[PATCH v19 0/7] firmware: arm_rmm: Add RMM v2.0 base RMI support

[PATCH v19 0/7] firmware: arm_rmm: Add RMM v2.0 base RMI support

[Suzuki K Poulose]

This series adds the generic firmware layer for talking to the Realm
Management Monitor (RMM), as specified by the RMM v2.0-bet3
specification[1]. It is the first part of the Arm CCA host support that
was previously posted as part of the larger KVM series.

The split allows this RMM support to be used as a base for other work,
including Aneesh's PCI IDE support with Arm CCA RMM as the TSM,
 without depending on the KVM Realm support that will follow as separate
 series. (See more on that below)

The series adds:

 * The RMI SMC definitions and direct-call wrappers.

 * RMM discovery and version checks during firmware init.

 * RMM host configuration, including the host page size.

 * Stateful RMI Operation (SRO) infrastructure for commands which the RMM
   can complete across multiple SMC calls while requesting or returning
   memory to the host.

 * Verification that granule tracking is available at fine granularity.
   Fine-grained tracking allows each granule in the system to be tracked
   independently, which is required before individual granules can be
   delegated. A future series will add support for dynamically supplying
   memory to the RMM for this tracking.

 * Support for fully firmware-managed systems, where the Granule Protection
   Tables for memory regions are allocated and managed by firmware. RMM v2.0
   also allows dynamic GPT creation on demand; support for that will be added
   in a later series.

 * Wrappers for the RMI commands that are used for managing the "Realm VM"
   lifecycle. This is added in to make it easier for the on-going KVM support
   to evolve in parallel pieces.

If the platform firmware cannot manage the granule tracking or the GPTs, we
bail out and deactivate the RMM, reclaiming any memory that we have donated.

The RMM v2.0 spec introduces Stateful RMI Operations (SROs), which allow
the RMM to complete an operation over several SMC calls while requesting
or returning memory to the host. This allows interrupts to be handled in
the middle of an operation and lets the RMM dynamically allocate memory
for internal tracking purposes. For example, RMI_REC_CREATE no longer
needs auxiliary granules to be provided up front, and can instead
request memory during the operation.

This series applies on v7.3-rc2 and a branch is available at [2]. The KVM
CCA support that builds on this series is available at [3] as an integration
branch. The KVM support depends on guest-memfd-in-place conversion support v13
from Ackerley [4], we plan to split that into parts, which apply cleanly on
v7.3-rcx without any dependency and is in progress. This will be made available
as soon as it is ready. Until then [3] shows how this base series enables KVM
CCA support. You may find the tf-RMM [5] and kvmtool support [6] below.

[1] RMM spec : https://support.arm.com/documentation/den0137/2-0bet3/
[2] This series: https://gitlab.arm.com/linux-arm/linux-cca.git cca/cca-host/fw_rmm/v19
[3] KVM CCA v17 integration branch: https://gitlab.arm.com/linux-arm/linux-cca.git cca/cca/cca-host/kvm-v20/integration
[4] Gmem inplace conversion https://github.com/googleprodkernel/linux-cc/tree/guest_memfd-inplace-conversion-v13
[5] TF-RMM https://git.trustedfirmware.org/TF-RMM/tf-rmm.git main (commit: 134266ae)
[6] kvmtool https://gitlab.arm.com/linux-arm/kvmtool-cca.git tag:cca-kvm-v20 (Also cca/kvm-v18)

Known issues: RMMv2.0 spec.
 * RmiOpMemDonateReq:count (Uint14) is incompatible with RmiAddrRangeDesc4KB
  (Uint10) and RmiAddrRangeDesc16KB (Uint12). i.e., a larger contiguous request
  may not be satisfiable by the host. This is resolved in the RMM spec, by clamping
  the upper limit on the number to match the RmiAddrRangeDesc* and will be published
  in the next release.
 * RMM to clarify the scenarios that triggers the RMI_BLOCKED and the
   recommendations to limit the cases.

Changes since v18:
 - Use _ULL version for masks spanning beyond 32bits
 - Add GENMASK, FIELD_* friends for RMI_ABI_VERSION_*
 - Consistent naming for masks and order the fields by MSB to LSB (missed out
   ones.
 - Rename RMI_RETURN_ => RMI_RESULT, RMI_RETURN_INDEX => RMI_RESULT_DATA_LEVEL
   and add relevant Rmi types for clear indication on what they represent.
 - Read and cache all implemented RmiFeatureRegisters (5), use ARRAY_SIZE()
   droping the macro for the number of registers.
 - Fold sinlge caller rmi calls to the caller (rmi_features)
 - Drop "default y" from Kconfig
 - Don't loop forever with RMI_BLOCKED, instead retry once and return to the
   caller.
 - Move rmi_config_set closer to rmi_configure.
 - Use __free() cleanup for rmm_config object
 - SRO: Clamp the mem donate request count to RMI_MAX_ADDR_LIST (the max we can
   hold in the struct sro, to prevent overflows in handling non_contig requests
 - Donate gathered memory when sro list runs out of space for non_contig case
   and donate the rest in the next iteration
 - Fix handling of buggy RMM for rmi_delegate_range()
 - Add comments for the exported interfaces rmi_delegate_range(), rmi_undelegate_range()
 - Move rmi_granule_{,un}delegate_range() closer to their callers
 - Clarify the requirements for rmi_granule_delegate_range()
 - Fix return result to -ENXIO if the MEM_OP is unknown
 - Handle unsupported RMI_OP_MEM_CONDITIONAL, bail out early
 - Rename "out" lable to mem_donate, where the actual donation happens
 - Switch to use readable loop construct in donate_noncontig, add comments
   to explain what we do.
 - Add comment, make the code reader friendly for caching the entries not
   consumed by RMM.
 - Add documentatoin for rmi_sro_execute()
 - Avoid mixing gotos with __free cleanups for arm64_init_rmi()
 - Convert the remaining nested if for results to early return based.
 - Pass out_top for RMI_ERROR_RTT in rmi_rtt_destroy() [ This boosts the
   Realm tear down ]

Changes since v17:
 - All RMIs are now issued using smccc-v1.2 helpers as mandated by the RMM
 - Add a helper function to reclaim an RmiAddrRange entry, which may be partially
   consumed. Used by rmi_sro_free and by rmi_sro_donate_*contig to reclaim
   partially consumed granules.
 - Move all RMI wrappers that are used only by rmi.c out of the arm-rmi-cmds.h
 - Rename macros, varibles to match RMM spec
 - Handle buggy RMM cases and sanitise the output values
 - Change sro_state.addr_count to int, giving us better handling of overflows
   and RMM bugs.
 - Avoid splling literal pools on stack for sro initialisation.
 - Print error messages for critical failures during RMM init
 - Use scope based cleanup for SRO object
 - Prevent overflow for donated_granules output from buggy RMM
 - Handle corrupted addr_count in the sro
 - Handle buggy RMM when the out_top is not changed with RMI_SUCCESS
   for delegate/undelegate range calls
 - Rename free_delegated_page => rmi_free_delegated_page
 - Rename donate_req_to_unit_size => donate_req_to_block_size
 - Introduce rmi_addr_block_size_to_bytes() helper to convert a RmiAddrBlockSize
   encoding used in RMI_DONATE_REQ and RMI_ADDR_RANGE Descriptors, replaces
   donate_req_to_unit_size(). Matches the RMM spec.
 - Rename unit_size => block_size_fld, unit_size_bytes => block_size etc.
 - Explicitly check for MEM_CONTIG/CAN_CANCEL fields to match the RMM spec values.
 - Rename free_delegated_page => rmi_free_delegated_page()
 - Drop RMI_BUSY, RMI_BLOCKED checks from rmi_*delegate_range as they are already
   handled by the rmi_smccc_invoke() used by the SRO.
 - Ensure RMI_OP_RECLAIM output is valid before consumption
 - Use GENMASK()/BIT() for masks consistently for RMI SMCCC defintions
 - Rename RMI_{ADDR_RANGE, DONATE}_SIZE => RMI_{*}_BLOCK_SIZE
 - Reorder the definitions for MSB to LSB
 - Add definions for RMI_OP_MEM_*CONTIG and RMI_OP_CAN*_CANCEL



Steven Price (6):
  firmware: arm_rmm: Add SMC definitions for calling the RMM
  firmware: arm_rmm: Check for RMI support at init
  firmware: arm_rmm: Add support for SRO
  firmware: arm_rmm: Activate the RMM
  firmware: arm_rmm: Ensure the RMM has GPT entries for memory
  firmware: arm_rmm: Add wrappers for Realm related RMI commands

Suzuki K Poulose (1):
  firmware: arm_rmm: Configure the RMM with the host's page size

 arch/arm64/Kconfig                |    1 +
 arch/arm64/kernel/cpufeature.c    |    1 +
 drivers/firmware/Kconfig          |    1 +
 drivers/firmware/Makefile         |    1 +
 drivers/firmware/arm_rmm/Kconfig  |   25 +
 drivers/firmware/arm_rmm/Makefile |    2 +
 drivers/firmware/arm_rmm/rmi.c    | 1072 +++++++++++++++++++++++++++++
 include/linux/arm-rmi-cmds.h      |  558 +++++++++++++++
 include/linux/arm-smccc-rmi.h     |  505 ++++++++++++++
 9 files changed, 2166 insertions(+)
 create mode 100644 drivers/firmware/arm_rmm/Kconfig
 create mode 100644 drivers/firmware/arm_rmm/Makefile
 create mode 100644 drivers/firmware/arm_rmm/rmi.c
 create mode 100644 include/linux/arm-rmi-cmds.h
 create mode 100644 include/linux/arm-smccc-rmi.h

-- 
2.43.0

[PATCH v19 1/7] firmware: arm_rmm: Add SMC definitions for calling the RMM

[Suzuki K Poulose]

From: Steven Price <steven.price@arm.com>

The RMM (Realm Management Monitor) provides functionality that can be
accessed by SMC calls from the host.

The SMC definitions are based on DEN0137[1] version 2.0-bet3

[1] https://developer.arm.com/documentation/den0137/2-0bet3/

Reviewed-by: Gavin Shan <gshan@redhat.com>
Signed-off-by: Steven Price <steven.price@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
---
 Changes since v18:
  * Use _ULL version for masks spanning beyond 32bits
  * Add GENMASK, FIELD_GET, FIELD_PREP for RMI_ABI_VERSION_*
  * Consistent naming for masks, order the remaing ones by MSB to LSB
  * Rename RMI_RETURN_ => RMI_RESULT and add relevant Rmi types for
    clear indication on what they represent.
 Changes since v17:
  * Use GENMASK()/BIT() for masks consistently
  * Rename RMI_{ADDR_RANGE, DONATE}_SIZE => RMI_{*}_BLOCK_SIZE
  * Reorder the definitions for MSB to LSB
  * Add definions for RMI_OP_MEM_*CONTIG and RMI_OP_CAN*_CANCEL
 Changes since v16:
  * Updated definitions to RMM specification v2.0-bet3.
 Changes since v15:
  * Dropped unused symbols REC_MAX_GIC_NUM_LRS and RMI_PERMITTED_GICV3_HCR_BITS.
  * Output is now (partially) generated from the spec source.
 Changes since v14:
  * Updated to RMM spec v2.0-bet2 but without the changes to move
    metadata out of individual address range descriptors as this is
    expected to be reverted in a future spec release.
 Changes since v13:
  * Updated to RMM spec v2.0-bet1
 Changes since v12:
  * Updated to RMM spec v2.0-bet0
 Changes since v9:
  * Corrected size of 'ripas_value' in struct rec_exit. The spec states
    this is an 8-bit type with padding afterwards (rather than a u64).
 Changes since v8:
  * Added RMI_PERMITTED_GICV3_HCR_BITS to define which bits the RMM
    permits to be modified.
 Changes since v6:
  * Renamed REC_ENTER_xxx defines to include 'FLAG' to make it obvious
    these are flag values.
 Changes since v5:
  * Sorted the SMC #defines by value.
  * Renamed SMI_RxI_CALL to SMI_RMI_CALL since the macro is only used for
    RMI calls.
  * Renamed REC_GIC_NUM_LRS to REC_MAX_GIC_NUM_LRS since the actual
    number of available list registers could be lower.
  * Provided a define for the reserved fields of FeatureRegister0.
  * Fix inconsistent names for padding fields.
 Changes since v4:
  * Update to point to final released RMM spec.
  * Minor rearrangements.
 Changes since v3:
  * Update to match RMM spec v1.0-rel0-rc1.
 Changes since v2:
  * Fix specification link.
  * Rename rec_entry->rec_enter to match spec.
  * Fix size of pmu_ovf_status to match spec.
---
 include/linux/arm-smccc-rmi.h | 505 ++++++++++++++++++++++++++++++++++
 1 file changed, 505 insertions(+)
 create mode 100644 include/linux/arm-smccc-rmi.h

diff --git a/include/linux/arm-smccc-rmi.h b/include/linux/arm-smccc-rmi.h
new file mode 100644
index 0000000000000..3b2a3ae6d81cd
--- /dev/null
+++ b/include/linux/arm-smccc-rmi.h
@@ -0,0 +1,505 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2023-2026 ARM Ltd.
+ *
+ * The values and structures in this file are from the Realm Management Monitor
+ * specification (DEN0137) version 2.0-bet3:
+ * https://developer.arm.com/documentation/den0137/2-0bet3/
+ */
+
+#ifndef __LINUX_ARM_SMCCC_RMI_H_
+#define __LINUX_ARM_SMCCC_RMI_H_
+
+#include <linux/arm-smccc.h>
+#include <linux/bitfield.h>
+#include <linux/bits.h>
+#include <linux/build_bug.h>
+#include <linux/sizes.h>
+
+#include <asm/page.h>
+
+#define SMC_RMI_CALL(func)				\
+	ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL,		\
+			   ARM_SMCCC_SMC_64,		\
+			   ARM_SMCCC_OWNER_STANDARD,	\
+			   (func))
+
+#define SMC_RMI_VERSION				SMC_RMI_CALL(0x0150)
+
+#define SMC_RMI_RTT_DATA_MAP_INIT		SMC_RMI_CALL(0x0153)
+
+#define SMC_RMI_REALM_ACTIVATE			SMC_RMI_CALL(0x0157)
+#define SMC_RMI_REALM_CREATE			SMC_RMI_CALL(0x0158)
+#define SMC_RMI_REALM_DESTROY			SMC_RMI_CALL(0x0159)
+#define SMC_RMI_REC_CREATE			SMC_RMI_CALL(0x015a)
+#define SMC_RMI_REC_DESTROY			SMC_RMI_CALL(0x015b)
+#define SMC_RMI_REC_ENTER			SMC_RMI_CALL(0x015c)
+#define SMC_RMI_RTT_CREATE			SMC_RMI_CALL(0x015d)
+#define SMC_RMI_RTT_DESTROY			SMC_RMI_CALL(0x015e)
+
+#define SMC_RMI_RTT_READ_ENTRY			SMC_RMI_CALL(0x0161)
+
+#define SMC_RMI_RTT_DEV_VALIDATE		SMC_RMI_CALL(0x0163)
+#define SMC_RMI_PSCI_COMPLETE			SMC_RMI_CALL(0x0164)
+#define SMC_RMI_FEATURES			SMC_RMI_CALL(0x0165)
+#define SMC_RMI_RTT_FOLD			SMC_RMI_CALL(0x0166)
+
+#define SMC_RMI_RTT_INIT_RIPAS			SMC_RMI_CALL(0x0168)
+#define SMC_RMI_RTT_SET_RIPAS			SMC_RMI_CALL(0x0169)
+#define SMC_RMI_VSMMU_CREATE			SMC_RMI_CALL(0x016a)
+#define SMC_RMI_VSMMU_DESTROY			SMC_RMI_CALL(0x016b)
+
+#define SMC_RMI_RMM_CONFIG_SET			SMC_RMI_CALL(0x016e)
+#define SMC_RMI_PSMMU_IRQ_NOTIFY		SMC_RMI_CALL(0x016f)
+#define SMC_RMI_ATTEST_PLAT_TOKEN_REFRESH	SMC_RMI_CALL(0x0170)
+
+#define SMC_RMI_PDEV_ABORT			SMC_RMI_CALL(0x0174)
+#define SMC_RMI_PDEV_COMMUNICATE		SMC_RMI_CALL(0x0175)
+#define SMC_RMI_PDEV_CREATE			SMC_RMI_CALL(0x0176)
+#define SMC_RMI_PDEV_DESTROY			SMC_RMI_CALL(0x0177)
+#define SMC_RMI_PDEV_GET_STATE			SMC_RMI_CALL(0x0178)
+
+#define SMC_RMI_PDEV_STREAM_KEY_REFRESH		SMC_RMI_CALL(0x017a)
+#define SMC_RMI_PDEV_SET_PUBKEY			SMC_RMI_CALL(0x017b)
+#define SMC_RMI_PDEV_STOP			SMC_RMI_CALL(0x017c)
+#define SMC_RMI_RTT_AUX_CREATE			SMC_RMI_CALL(0x017d)
+#define SMC_RMI_RTT_AUX_DESTROY			SMC_RMI_CALL(0x017e)
+#define SMC_RMI_RTT_AUX_FOLD			SMC_RMI_CALL(0x017f)
+
+#define SMC_RMI_VDEV_ABORT			SMC_RMI_CALL(0x0185)
+#define SMC_RMI_VDEV_COMMUNICATE		SMC_RMI_CALL(0x0186)
+#define SMC_RMI_VDEV_CREATE			SMC_RMI_CALL(0x0187)
+#define SMC_RMI_VDEV_DESTROY			SMC_RMI_CALL(0x0188)
+#define SMC_RMI_VDEV_GET_STATE			SMC_RMI_CALL(0x0189)
+#define SMC_RMI_VDEV_UNLOCK			SMC_RMI_CALL(0x018a)
+#define SMC_RMI_RTT_SET_S2AP			SMC_RMI_CALL(0x018b)
+
+#define SMC_RMI_VDEV_GET_INTERFACE_REPORT	SMC_RMI_CALL(0x01d0)
+#define SMC_RMI_VDEV_GET_MEASUREMENTS		SMC_RMI_CALL(0x01d1)
+#define SMC_RMI_VDEV_LOCK			SMC_RMI_CALL(0x01d2)
+#define SMC_RMI_VDEV_START			SMC_RMI_CALL(0x01d3)
+
+#define SMC_RMI_VSMMU_EVENT_HANDLE		SMC_RMI_CALL(0x01d6)
+#define SMC_RMI_PSMMU_ACTIVATE			SMC_RMI_CALL(0x01d7)
+#define SMC_RMI_PSMMU_DEACTIVATE		SMC_RMI_CALL(0x01d8)
+
+#define SMC_RMI_PSMMU_ST_L2_CREATE		SMC_RMI_CALL(0x01db)
+#define SMC_RMI_PSMMU_ST_L2_DESTROY		SMC_RMI_CALL(0x01dc)
+#define SMC_RMI_DPT_L0_CREATE			SMC_RMI_CALL(0x01dd)
+#define SMC_RMI_DPT_L0_DESTROY			SMC_RMI_CALL(0x01de)
+#define SMC_RMI_DPT_L1_CREATE			SMC_RMI_CALL(0x01df)
+#define SMC_RMI_DPT_L1_DESTROY			SMC_RMI_CALL(0x01e0)
+#define SMC_RMI_GRANULE_TRACKING_GET		SMC_RMI_CALL(0x01e1)
+
+#define SMC_RMI_GRANULE_TRACKING_SET		SMC_RMI_CALL(0x01e3)
+
+#define SMC_RMI_RMM_CONFIG_GET			SMC_RMI_CALL(0x01ec)
+
+#define SMC_RMI_RMM_STATE_GET			SMC_RMI_CALL(0x01ee)
+
+#define SMC_RMI_PSMMU_EVENT_CONSUME		SMC_RMI_CALL(0x01f0)
+#define SMC_RMI_GRANULE_RANGE_DELEGATE		SMC_RMI_CALL(0x01f1)
+#define SMC_RMI_GRANULE_RANGE_UNDELEGATE	SMC_RMI_CALL(0x01f2)
+#define SMC_RMI_GPT_L1_CREATE			SMC_RMI_CALL(0x01f3)
+#define SMC_RMI_GPT_L1_DESTROY			SMC_RMI_CALL(0x01f4)
+#define SMC_RMI_RTT_DATA_MAP			SMC_RMI_CALL(0x01f5)
+#define SMC_RMI_RTT_DATA_UNMAP			SMC_RMI_CALL(0x01f6)
+#define SMC_RMI_RTT_DEV_MAP			SMC_RMI_CALL(0x01f7)
+#define SMC_RMI_RTT_DEV_UNMAP			SMC_RMI_CALL(0x01f8)
+#define SMC_RMI_RTT_ARCH_DEV_MAP		SMC_RMI_CALL(0x01f9)
+#define SMC_RMI_RTT_ARCH_DEV_UNMAP		SMC_RMI_CALL(0x01fa)
+#define SMC_RMI_RTT_UNPROT_MAP			SMC_RMI_CALL(0x01fb)
+#define SMC_RMI_RTT_UNPROT_UNMAP		SMC_RMI_CALL(0x01fc)
+#define SMC_RMI_RTT_AUX_PROT_MAP		SMC_RMI_CALL(0x01fd)
+#define SMC_RMI_RTT_AUX_PROT_UNMAP		SMC_RMI_CALL(0x01fe)
+#define SMC_RMI_RTT_AUX_UNPROT_MAP		SMC_RMI_CALL(0x01ff)
+#define SMC_RMI_RTT_AUX_UNPROT_UNMAP		SMC_RMI_CALL(0x0200)
+#define SMC_RMI_REALM_TERMINATE			SMC_RMI_CALL(0x0201)
+#define SMC_RMI_RMM_ACTIVATE			SMC_RMI_CALL(0x0202)
+#define SMC_RMI_OP_CONTINUE			SMC_RMI_CALL(0x0203)
+#define SMC_RMI_PDEV_STREAM_CONNECT		SMC_RMI_CALL(0x0204)
+#define SMC_RMI_PDEV_STREAM_DISCONNECT		SMC_RMI_CALL(0x0205)
+#define SMC_RMI_PDEV_STREAM_COMPLETE		SMC_RMI_CALL(0x0206)
+#define SMC_RMI_PDEV_STREAM_KEY_PURGE		SMC_RMI_CALL(0x0207)
+#define SMC_RMI_OP_MEM_DONATE			SMC_RMI_CALL(0x0208)
+#define SMC_RMI_OP_MEM_RECLAIM			SMC_RMI_CALL(0x0209)
+#define SMC_RMI_OP_CANCEL			SMC_RMI_CALL(0x020a)
+#define SMC_RMI_VSMMU_FEATURES			SMC_RMI_CALL(0x020b)
+#define SMC_RMI_VSMMU_CMD_GET			SMC_RMI_CALL(0x020c)
+#define SMC_RMI_VSMMU_CMD_COMPLETE		SMC_RMI_CALL(0x020d)
+#define SMC_RMI_PSMMU_INFO			SMC_RMI_CALL(0x020e)
+#define SMC_RMI_RMM_DEACTIVATE			SMC_RMI_CALL(0x020f)
+#define SMC_RMI_PDEV_STREAM_INFO		SMC_RMI_CALL(0x0210)
+#define SMC_RMI_GPT_INFO			SMC_RMI_CALL(0x0211)
+
+#define RMI_ABI_MAJOR_VERSION	2
+#define RMI_ABI_MINOR_VERSION	0
+
+#define RMI_ABI_VERSION_MAJOR_MASK		GENMASK(30, 16)
+#define RMI_ABI_VERSION_MINOR_MASK		GENMASK(15, 0)
+
+#define RMI_ABI_VERSION_GET_MAJOR(v)	FIELD_GET(RMI_ABI_VERSION_MAJOR_MASK, (v))
+#define RMI_ABI_VERSION_GET_MINOR(v)	FIELD_GET(RMI_ABI_VERSION_MINOR_MASK, (v))
+#define RMI_ABI_VERSION(major, minor)				\
+	(FIELD_PREP(RMI_ABI_VERSION_MAJOR_MASK, (major)) |	\
+	 FIELD_PREP(RMI_ABI_VERSION_MINOR_MASK, (minor)))
+
+/* RmiResult Type definitions */
+#define RMI_RESULT_STATUS_MASK		GENMASK(7, 0)
+/* RmiResultDataLevel field */
+#define RMI_RESULT_DATA_LEVEL_MASK	GENMASK(15, 8)
+/* RmiResultDataIncomplete fields */
+#define RMI_RESULT_MEMREQ_MASK		GENMASK(9, 8)
+#define RMI_RESULT_CAN_CANCEL_MASK	BIT(10)
+
+#define RMI_RESULT_STATUS(ret)		FIELD_GET(RMI_RESULT_STATUS_MASK, ret)
+#define RMI_RESULT_DATA_LEVEL(ret)	FIELD_GET(RMI_RESULT_DATA_LEVEL_MASK, ret)
+#define RMI_RESULT_MEMREQ(ret)		FIELD_GET(RMI_RESULT_MEMREQ_MASK, ret)
+#define RMI_RESULT_CAN_CANCEL(ret)	FIELD_GET(RMI_RESULT_CAN_CANCEL_MASK, ret)
+
+#define RMI_SUCCESS			0
+#define RMI_ERROR_INPUT			1
+#define RMI_ERROR_REALM			2
+#define RMI_ERROR_REC			3
+#define RMI_ERROR_RTT			4
+#define RMI_ERROR_NOT_SUPPORTED		5
+#define RMI_ERROR_DEVICE		6
+#define RMI_ERROR_RTT_AUX		7
+#define RMI_ERROR_PSMMU_ST		8
+#define RMI_ERROR_DPT			9
+#define RMI_BUSY			10
+#define RMI_ERROR_GLOBAL		11
+#define RMI_ERROR_TRACKING		12
+#define RMI_INCOMPLETE			13
+#define RMI_BLOCKED			14
+#define RMI_ERROR_GPT			15
+#define RMI_ERROR_GRANULE		16
+
+#define RMI_CONTINUE_KEEP_GOING		0
+#define RMI_CONTINUE_STOP		1
+
+#define RMI_OP_MEM_REQ_NONE		0
+#define RMI_OP_MEM_REQ_DONATE		1
+#define RMI_OP_MEM_REQ_RECLAIM		2
+
+#define RMI_OP_CANNOT_CANCEL		0
+#define RMI_OP_CAN_CANCEL		1
+
+#define RMI_DONATE_STATE_MASK		GENMASK(18, 17)
+#define RMI_DONATE_CONTIG_MASK		BIT(16)
+#define RMI_DONATE_COUNT_MASK		GENMASK(15, 2)
+#define RMI_DONATE_BLOCK_SIZE_MASK	GENMASK(1, 0)
+
+#define RMI_DONATE_STATE(req)		FIELD_GET(RMI_DONATE_STATE_MASK, req)
+#define RMI_DONATE_CONTIG(req)		FIELD_GET(RMI_DONATE_CONTIG_MASK, req)
+#define RMI_DONATE_COUNT(req)		FIELD_GET(RMI_DONATE_COUNT_MASK, req)
+#define RMI_DONATE_BLOCK_SIZE(req)	FIELD_GET(RMI_DONATE_BLOCK_SIZE_MASK, req)
+
+#define RMI_OP_MEM_DELEGATED		0
+#define RMI_OP_MEM_UNDELEGATED		1
+#define RMI_OP_MEM_CONDITIONAL		2
+
+#define RMI_OP_MEM_NON_CONTIG		0
+#define RMI_OP_MEM_CONTIG		1
+
+#define RMI_ADDR_TYPE_NONE		0
+#define RMI_ADDR_TYPE_SINGLE		1
+#define RMI_ADDR_TYPE_LIST		2
+
+#define RMI_ADDR_RANGE_STATE_MASK	GENMASK_ULL(63, 62)
+#define RMI_ADDR_RANGE_ADDR_MASK	GENMASK_ULL(51, PAGE_SHIFT)
+#define RMI_ADDR_RANGE_COUNT_MASK	GENMASK(PAGE_SHIFT - 1, 2)
+#define RMI_ADDR_RANGE_BLOCK_SIZE_MASK	GENMASK(1, 0)
+
+#define RMI_ADDR_RANGE_STATE(r)		FIELD_GET(RMI_ADDR_RANGE_STATE_MASK, (r))
+#define RMI_ADDR_RANGE_ADDR(r)		((r) & RMI_ADDR_RANGE_ADDR_MASK)
+#define RMI_ADDR_RANGE_COUNT(r)		FIELD_GET(RMI_ADDR_RANGE_COUNT_MASK, (r))
+#define RMI_ADDR_RANGE_BLOCK_SIZE(r)	FIELD_GET(RMI_ADDR_RANGE_BLOCK_SIZE_MASK, (r))
+
+enum rmi_ripas {
+	RMI_EMPTY = 0,
+	RMI_RAM = 1,
+	RMI_DESTROYED = 2,
+	RMI_DEV = 3,
+};
+
+#define RMI_NO_MEASURE_CONTENT	0
+#define RMI_MEASURE_CONTENT	1
+
+#define RMI_FEATURE_REGISTER_0_S2OASZ			GENMASK_ULL(40, 33)
+#define RMI_FEATURE_REGISTER_0_L0GPT_BLOCK_DELEGATE	BIT_ULL(32)
+#define RMI_FEATURE_REGISTER_0_PMU_NUM_CTRS		GENMASK(31, 27)
+#define RMI_FEATURE_REGISTER_0_PMU			BIT(26)
+#define RMI_FEATURE_REGISTER_0_NUM_WPS			GENMASK(25, 20)
+#define RMI_FEATURE_REGISTER_0_NUM_BPS			GENMASK(19, 14)
+#define RMI_FEATURE_REGISTER_0_SVE_VL			GENMASK(13, 10)
+#define RMI_FEATURE_REGISTER_0_SVE			BIT(9)
+#define RMI_FEATURE_REGISTER_0_LPA2			BIT(8)
+#define RMI_FEATURE_REGISTER_0_S2SZ			GENMASK(7, 0)
+
+#define RMI_FEATURE_REGISTER_1_PPS			GENMASK(16, 14)
+#define RMI_FEATURE_REGISTER_1_L0GPTSZ			GENMASK(13, 10)
+#define RMI_FEATURE_REGISTER_1_MAX_RECS_ORDER		GENMASK(9, 6)
+#define RMI_FEATURE_REGISTER_1_HASH_SHA_512		BIT(5)
+#define RMI_FEATURE_REGISTER_1_HASH_SHA_384		BIT(4)
+#define RMI_FEATURE_REGISTER_1_HASH_SHA_256		BIT(3)
+#define RMI_FEATURE_REGISTER_1_RMI_GRAN_SZ_64KB		BIT(2)
+#define RMI_FEATURE_REGISTER_1_RMI_GRAN_SZ_16KB		BIT(1)
+#define RMI_FEATURE_REGISTER_1_RMI_GRAN_SZ_4KB		BIT(0)
+
+#define RMI_FEATURE_REGISTER_2_REALM_MAX_VDEVS_ORDER	GENMASK(14, 10)
+#define RMI_FEATURE_REGISTER_2_NON_TEE_STREAM		BIT(9)
+#define RMI_FEATURE_REGISTER_2_VDEV_KROU		BIT(8)
+#define RMI_FEATURE_REGISTER_2_PDEV_MAX_VDEVS_ORDER	GENMASK(7, 4)
+#define RMI_FEATURE_REGISTER_2_ATS			BIT(3)
+#define RMI_FEATURE_REGISTER_2_VSMMU			BIT(2)
+#define RMI_FEATURE_REGISTER_2_DA_COH			BIT(1)
+#define RMI_FEATURE_REGISTER_2_DA			BIT(0)
+
+#define RMI_FEATURE_REGISTER_3_RTT_S2AP_INDIRECT	BIT(6)
+#define RMI_FEATURE_REGISTER_3_RTT_PLANE		GENMASK(5, 4)
+#define RMI_FEATURE_REGISTER_3_MAX_NUM_AUX_PLANES	GENMASK(3, 0)
+
+#define RMI_FEATURE_REGISTER_4_MEC_COUNT		GENMASK_ULL(63, 0)
+
+#define RMI_MEM_CATEGORY_CONVENTIONAL		0
+#define RMI_MEM_CATEGORY_DEV_NCOH		1
+#define RMI_MEM_CATEGORY_DEV_COH		2
+#define RMI_MEM_CATEGORY_NONE			3
+
+#define RMI_TRACKING_RESERVED			0
+#define RMI_TRACKING_NONE			1
+#define RMI_TRACKING_FINE			2
+#define RMI_TRACKING_COARSE			3
+#define RMI_TRACKING_INTERMEDIATE		4
+
+#define RMI_GRANULE_SIZE_4KB	0
+#define RMI_GRANULE_SIZE_16KB	1
+#define RMI_GRANULE_SIZE_64KB	2
+
+#define RMI_GPT_PAR_RESERVED           0U
+#define RMI_GPT_PAR_PLAT               1U
+#define RMI_GPT_PAR_HOST_NOT_CREATED   2U
+#define RMI_GPT_PAR_HOST_CREATED       3U
+
+/*
+ * Note many of these fields are smaller than u64 but all fields have u64
+ * alignment, so use u64 to ensure correct alignment.
+ */
+struct rmm_config {
+	union { /* 0x0 */
+		struct {
+			u64 tracking_region_size;
+			u64 rmi_granule_size;
+		};
+		u8 sizer[SZ_4K];
+	};
+};
+
+static_assert(sizeof(struct rmm_config) == SZ_4K);
+
+#define RMI_REALM_PARAM_FLAG_MEC_POLICY_MASK	GENMASK(8, 7)
+#define RMI_REALM_PARAM_FLAG_LFA_POLICY_MASK	GENMASK(6, 5)
+#define RMI_REALM_PARAM_FLAG_DA			BIT(3)
+#define RMI_REALM_PARAM_FLAG_PMU		BIT(2)
+#define RMI_REALM_PARAM_FLAG_SVE		BIT(1)
+
+#define RMI_HASH_SHA_256			0
+#define RMI_HASH_SHA_512			1
+#define RMI_HASH_SHA_384			2
+
+struct realm_params {
+	union { /* 0x0 */
+		struct {
+			u64 flags0;
+			u64 s2sz;
+			u64 sve_vl;
+			u64 num_bps;
+			u64 num_wps;
+			u64 pmu_num_ctrs;
+			u64 hash_algo;
+			u64 num_aux_planes;
+		};
+		u8 padding0[0x400];
+	};
+	union { /* 0x400 */
+		struct {
+			u8 rpv[64];
+			u64 ats_plane;
+		};
+		u8 padding1[0x400];
+	};
+	union { /* 0x800 */
+		struct {
+			u64 padding2;
+			u64 rtt_base;
+			s64 rtt_level_start;
+			u64 rtt_num_start;
+			u64 flags1;
+			u64 max_num_vdevs;
+		};
+		u8 padding3[0x700];
+	};
+	union { /* 0xf00 */
+		struct {
+			u8 padding4[0x80];
+			u64 aux_rtt_base[3];
+		};
+		u8 padding5[0x100];
+	};
+};
+
+static_assert(sizeof(struct realm_params) == SZ_4K);
+
+/*
+ * The number of GPRs (starting from X0) that are configured by the host when
+ * a REC is created.
+ */
+#define REC_CREATE_NR_GPRS		8
+
+#define REC_PARAMS_FLAG_RUNNABLE	BIT(0)
+
+struct rec_params {
+	union { /* 0x0 */
+		u64 flags;
+		u8 padding0[0x100];
+	};
+	union { /* 0x100 */
+		u64 mpidr;
+		u8 padding1[0x100];
+	};
+	union { /* 0x200 */
+		u64 pc;
+		u8 padding2[0x100];
+	};
+	union { /* 0x300 */
+		u64 gprs[REC_CREATE_NR_GPRS];
+		u8 padding3[0xd00];
+	};
+};
+
+static_assert(sizeof(struct rec_params) == SZ_4K);
+
+#define REC_ENTER_FLAG_FORCE_P0		BIT(7)
+#define REC_ENTER_FLAG_DEV_MEM_RESPONSE	BIT(6)
+#define REC_ENTER_FLAG_S2AP_RESPONSE	BIT(5)
+#define REC_ENTER_FLAG_RIPAS_RESPONSE	BIT(4)
+#define REC_ENTER_FLAG_TRAP_WFE		BIT(3)
+#define REC_ENTER_FLAG_TRAP_WFI		BIT(2)
+#define REC_ENTER_FLAG_INJECT_SEA	BIT(1)
+#define REC_ENTER_FLAG_EMULATED_MMIO	BIT(0)
+
+#define REC_RUN_GPRS			31
+
+struct rec_enter {
+	union { /* 0x000 */
+		u64 flags;
+		u8 padding0[0x200];
+	};
+	union { /* 0x200 */
+		u64 gprs[REC_RUN_GPRS];
+		u8 padding1[0x600];
+	};
+};
+
+static_assert(sizeof(struct rec_enter) == SZ_2K);
+
+#define RMI_EXIT_SYNC			0x00
+#define RMI_EXIT_IRQ			0x01
+#define RMI_EXIT_FIQ			0x02
+#define RMI_EXIT_PSCI			0x03
+#define RMI_EXIT_RIPAS_CHANGE		0x04
+#define RMI_EXIT_HOST_CALL		0x05
+#define RMI_EXIT_SERROR			0x06
+#define RMI_EXIT_S2AP_CHANGE		0x07
+#define RMI_EXIT_VDEV_VALIDATE_MAPPING	0x08
+#define RMI_EXIT_VSMMU_COMMAND		0x0a
+
+struct rec_exit {
+	union { /* 0x000 */
+		u8 exit_reason;
+		u8 padding0[0x100];
+	};
+	union { /* 0x100 */
+		struct {
+			u64 esr;
+			u64 far;
+			u64 hpfar;
+			u64 rtt_tree;
+		};
+		u8 padding1[0x100];
+	};
+	union { /* 0x200 */
+		u64 gprs[REC_RUN_GPRS];
+		u8 padding2[0x100];
+	};
+	union { /* 0x300 */
+		u8 padding3[0x100];
+	};
+	union { /* 0x400 */
+		struct {
+			u64 cntp_ctl;
+			u64 cntp_cval;
+			u64 cntv_ctl;
+			u64 cntv_cval;
+		};
+		u8 padding4[0x100];
+	};
+	union { /* 0x500 */
+		struct {
+			u64 ripas_base;
+			u64 ripas_top;
+			u8 ripas_value;
+			u8 padding5[0xf];
+			u64 s2ap_base;
+			u64 s2ap_top;
+			u64 vdev_id_1;
+			u64 vdev_id_2;
+			u64 dev_mem_base;
+			u64 dev_mem_top;
+			u64 dev_mem_pa;
+		};
+		u8 padding6[0x100];
+	};
+	union { /* 0x600 */
+		struct {
+			u16 imm;
+			u8 padding7[0x6];
+			u64 plane;
+		};
+		u8 padding8[0x100];
+	};
+	union { /* 0x700 */
+		struct {
+			u8 pmu_ovf_status;
+			u8 padding9[0xf];
+			u64 vsmmu;
+		};
+		u8 padding10[0x100];
+	};
+};
+
+static_assert(sizeof(struct rec_exit) == SZ_2K);
+
+struct rec_run {
+	struct rec_enter enter;
+	struct rec_exit exit;
+};
+
+static_assert(sizeof(struct rec_run) == SZ_4K);
+
+/* RMI_RTT_UNPROT_MAP_FLAGS definitions */
+#define RMI_RTT_UNPROT_MAP_FLAGS_S2AP_MASK		GENMASK(22, 19)
+#define RMI_RTT_UNPROT_MAP_FLAGS_MEMATTR_MASK		GENMASK(18, 16)
+#define RMI_RTT_UNPROT_MAP_FLAGS_LIST_COUNT_MASK	GENMASK(15, 2)
+#define RMI_RTT_UNPROT_MAP_FLAGS_OADDR_TYPE_MASK	GENMASK(1, 0)
+
+/* RMI_RTT_PROT_MAP_FLAGS definitions */
+#define RMI_RTT_PROT_MAP_FLAGS_LIST_COUNT_MASK		GENMASK(15, 2)
+#define RMI_RTT_PROT_MAP_FLAGS_OADDR_TYPE_MASK		GENMASK(1, 0)
+
+/* S2AP Direct Encodings, used in RMI_RTT_UNPROT_MAP_FLAGS_S2AP */
+#define RMI_S2AP_DIRECT_READ			BIT(1)
+#define RMI_S2AP_DIRECT_WRITE			BIT(0)
+
+#endif /* __LINUX_ARM_SMCCC_RMI_H_ */
-- 
2.43.0

[PATCH v19 2/7] firmware: arm_rmm: Check for RMI support at init

[Suzuki K Poulose]

From: Steven Price <steven.price@arm.com>

Query the RMI version number and check if it is a compatible version.
The first two feature registers are read and exposed for future code to
use.

We only support this for Little Endian kernels, the Big Endian kernel
support is anyway marked BROKEN and is being removed.

Signed-off-by: Steven Price <steven.price@arm.com>
Co-developed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
---
v19:
 * Read all implemented RmiFeatureRegisters - 5
 * Use ARRAY_SIZE(rmi_feat_reg_cache) for the loop in rmi_read_features()
 * Fold rmi_features() into rmi_read_features
 * Fix comment for rmi_smccc_invoke()
 * Drop default y
 * Add retry for RMI_BLOCKED and return to caller
v18:
 * Always use arm_smccc_1_2_invoke() for all RMIs making sure the unsused
   parameters are 0 - Sashiko
 * Move rmi_features() calls away from the arm-rmi-cmds.h to rmi.c - Gavin
v17:
 * Rename ARM_RMM to ARM_RMM_RMI to make it easier to add Guest facing RSI
   support, which is also in progress
v16:
 * Update Kconfig text to include PCIe TDISP.
 * Export rmi_feat_reg() here rather than in a later commit.
v15:
 * The code is moved again, this time into the 'firmware' directory.
v14:
 * This moves the basic RMI setup into the 'kernel' directory. This is
   because RMI will be used for some features outside of KVM so should
   be available even if KVM isn't compiled in.
---
 arch/arm64/Kconfig                |   1 +
 arch/arm64/kernel/cpufeature.c    |   1 +
 drivers/firmware/Kconfig          |   1 +
 drivers/firmware/Makefile         |   1 +
 drivers/firmware/arm_rmm/Kconfig  |  25 +++++++
 drivers/firmware/arm_rmm/Makefile |   2 +
 drivers/firmware/arm_rmm/rmi.c    | 109 ++++++++++++++++++++++++++++++
 include/linux/arm-rmi-cmds.h      |  48 +++++++++++++
 8 files changed, 188 insertions(+)
 create mode 100644 drivers/firmware/arm_rmm/Kconfig
 create mode 100644 drivers/firmware/arm_rmm/Makefile
 create mode 100644 drivers/firmware/arm_rmm/rmi.c
 create mode 100644 include/linux/arm-rmi-cmds.h

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index b5a51b0ef9440..ff9565d3ffa59 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -38,6 +38,7 @@ config ARM64
 	select ARCH_HAS_MEMBARRIER_SYNC_CORE
 	select ARCH_HAS_MEM_ENCRYPT
 	select ARCH_SUPPORTS_MSEAL_SYSTEM_MAPPINGS
+	select ARCH_SUPPORTS_RMM
 	select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS
 	select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
 	select ARCH_HAS_NONLEAF_PMD_YOUNG if ARM64_HAFT
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index 32102c3912fa7..e8b29983b0021 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -293,6 +293,7 @@ static const struct arm64_ftr_bits ftr_id_aa64isar3[] = {
 static const struct arm64_ftr_bits ftr_id_aa64pfr0[] = {
 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR0_EL1_CSV3_SHIFT, 4, 0),
 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR0_EL1_CSV2_SHIFT, 4, 0),
+	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR0_EL1_RME_SHIFT, 4, 0),
 	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_EL1_DIT_SHIFT, 4, 0),
 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR0_EL1_AMU_SHIFT, 4, 0),
 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR0_EL1_MPAM_SHIFT, 4, 0),
diff --git a/drivers/firmware/Kconfig b/drivers/firmware/Kconfig
index b7cc11e4fbfa6..62660bf520a8d 100644
--- a/drivers/firmware/Kconfig
+++ b/drivers/firmware/Kconfig
@@ -310,5 +310,6 @@ source "drivers/firmware/samsung/Kconfig"
 source "drivers/firmware/smccc/Kconfig"
 source "drivers/firmware/tegra/Kconfig"
 source "drivers/firmware/xilinx/Kconfig"
+source "drivers/firmware/arm_rmm/Kconfig"
 
 endmenu
diff --git a/drivers/firmware/Makefile b/drivers/firmware/Makefile
index be46f1e1dc77f..196a650ccf025 100644
--- a/drivers/firmware/Makefile
+++ b/drivers/firmware/Makefile
@@ -39,3 +39,4 @@ obj-y				+= samsung/
 obj-y				+= smccc/
 obj-y				+= tegra/
 obj-y				+= xilinx/
+obj-y				+= arm_rmm/
diff --git a/drivers/firmware/arm_rmm/Kconfig b/drivers/firmware/arm_rmm/Kconfig
new file mode 100644
index 0000000000000..a37cba6647360
--- /dev/null
+++ b/drivers/firmware/arm_rmm/Kconfig
@@ -0,0 +1,25 @@
+
+config ARCH_SUPPORTS_RMM
+	bool
+
+config ARM_RMM_RMI
+	bool "Realm Management Interface (RMI) Support"
+	depends on ARCH_SUPPORTS_RMM
+	help
+	  Support the Realm Management Monitor (RMM) on Arm systems that
+	  implement the Realm Management Extension (RME), as defined by the
+	  Arm Confidential Compute Architecture.
+
+	  The RMM runs at EL2 in the Realm world and provides the Realm
+	  Management Interface (RMI) used by a Normal World host to create,
+	  manage and run protected virtual machines called Realms. The RMM can
+	  also act as a TSM, as defined by the PCIe TDISP and can manage the
+	  PCI IDE setup for securing the PCIe links.
+
+	  This option builds the host-side RMI support used by KVM to detect a
+	  compatible RMM, configure it, manage delegated memory and enable
+	  Realm guests.
+
+	  Selecting this option does not by itself make Realm guests available:
+	  the system must also provide RME-capable hardware and firmware with a
+	  compatible RMM implementation.
diff --git a/drivers/firmware/arm_rmm/Makefile b/drivers/firmware/arm_rmm/Makefile
new file mode 100644
index 0000000000000..65171988fdcae
--- /dev/null
+++ b/drivers/firmware/arm_rmm/Makefile
@@ -0,0 +1,2 @@
+
+obj-$(CONFIG_ARM_RMM_RMI)	= rmi.o
diff --git a/drivers/firmware/arm_rmm/rmi.c b/drivers/firmware/arm_rmm/rmi.c
new file mode 100644
index 0000000000000..3baba931f92e4
--- /dev/null
+++ b/drivers/firmware/arm_rmm/rmi.c
@@ -0,0 +1,109 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2023-2026 ARM Ltd.
+ */
+
+#include <linux/cpufeature.h>
+#include <linux/memblock.h>
+#include <linux/arm-rmi-cmds.h>
+#include <linux/slab.h>
+
+#include <asm/memory.h>
+#include <asm/pgtable-hwdef.h>
+
+/* RMM defines RmiFeatureRegister0 to RmiFeatureRegister5. */
+static unsigned long rmi_feat_reg_cache[5] __ro_after_init;
+
+static int rmi_check_version(void)
+{
+	unsigned short version_major, version_minor;
+	unsigned long host_version = RMI_ABI_VERSION(RMI_ABI_MAJOR_VERSION,
+						     RMI_ABI_MINOR_VERSION);
+	unsigned long aa64pfr0 = read_sanitised_ftr_reg(SYS_ID_AA64PFR0_EL1);
+	struct arm_smccc_1_2_regs res = {
+		SMC_RMI_VERSION, host_version,
+	};
+
+	/* If RME isn't supported, then RMI can't be */
+	if (cpuid_feature_extract_unsigned_field(aa64pfr0, ID_AA64PFR0_EL1_RME_SHIFT) == 0)
+		return -ENXIO;
+
+	rmi_smccc_invoke(&res);
+	if (res.a0 == SMCCC_RET_NOT_SUPPORTED)
+		return -ENXIO;
+
+	version_major = RMI_ABI_VERSION_GET_MAJOR(res.a1);
+	version_minor = RMI_ABI_VERSION_GET_MINOR(res.a1);
+
+	if (res.a0 != RMI_SUCCESS) {
+		unsigned short high_version_major, high_version_minor;
+
+		high_version_major = RMI_ABI_VERSION_GET_MAJOR(res.a2);
+		high_version_minor = RMI_ABI_VERSION_GET_MINOR(res.a2);
+
+		pr_err("Unsupported RMI ABI (v%d.%d - v%d.%d) we want v%d.%d\n",
+		       version_major, version_minor,
+		       high_version_major, high_version_minor,
+		       RMI_ABI_MAJOR_VERSION,
+		       RMI_ABI_MINOR_VERSION);
+		return -ENXIO;
+	}
+
+	pr_info("RMI ABI version %d.%d\n", version_major, version_minor);
+
+	return 0;
+}
+
+static int rmi_read_features(void)
+{
+	/*
+	 * Since we've negotiated a compatible version these feature registers
+	 * should always be available
+	 */
+	for (int i = 0; i < ARRAY_SIZE(rmi_feat_reg_cache); i++) {
+		struct arm_smccc_1_2_regs args = {
+			SMC_RMI_FEATURES, i,
+		};
+
+		rmi_smccc_invoke(&args);
+		if (WARN_ON(args.a0 != RMI_SUCCESS))
+			return -EINVAL;
+
+		rmi_feat_reg_cache[i] = args.a1;
+	}
+
+	return 0;
+}
+
+unsigned long rmi_feat_reg(unsigned long index)
+{
+	if (WARN_ON(index >= ARRAY_SIZE(rmi_feat_reg_cache)))
+		return 0;
+
+	return rmi_feat_reg_cache[index];
+}
+EXPORT_SYMBOL_GPL(rmi_feat_reg);
+
+
+static int __init arm64_init_rmi(void)
+{
+	int ret;
+
+	/* If we can't agree on the RMI ABI version, don't proceed further */
+	ret = rmi_check_version();
+	if (ret)
+		return ret;
+
+	ret = rmi_read_features();
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+/*
+ * Note arm64_init_rmi() must be called before kvm_init_rmi() otherwise KVM
+ * will not support realm guests. subsys_initcall() is called before
+ * module_init() (used for KVM) so this is OK.
+ */
+subsys_initcall(arm64_init_rmi);
diff --git a/include/linux/arm-rmi-cmds.h b/include/linux/arm-rmi-cmds.h
new file mode 100644
index 0000000000000..5c6c563c81555
--- /dev/null
+++ b/include/linux/arm-rmi-cmds.h
@@ -0,0 +1,48 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2026 ARM Ltd.
+ */
+
+#ifndef __LINUX_ARM_RMI_CMDS_H_
+#define __LINUX_ARM_RMI_CMDS_H_
+
+#include <linux/arm-smccc-rmi.h>
+#include <linux/bug.h>
+#include <linux/processor.h>
+#include <linux/types.h>
+
+#define RMM_BLOCKED_RETRY_COUNT		2
+/*
+ * rmi_smccc_invoke: Invoke the RMI call and return the results, retrying the
+ * command when status is RMI_BUSY. If we encounter RMI_BLOCKED, we retry
+ * it one more time before we give up. The caller is supposed to handle the
+ * result and reissue if required.
+ *
+ * We don't expect to see RMI_BLOCKED on a practical system, except when
+ * there are parallel requests that results in long standing operation,
+ * with one blocking the other.
+ *
+ * @regs: Input parameters filled in. Updated with the ouptput results
+ * after the call.
+ */
+static inline void rmi_smccc_invoke(struct arm_smccc_1_2_regs *regs)
+{
+	struct arm_smccc_1_2_regs args = *regs;
+	long status;
+	int i = 0;
+
+	while (i < RMM_BLOCKED_RETRY_COUNT) {
+		arm_smccc_1_2_invoke(&args, regs);
+
+		status = RMI_RESULT_STATUS(regs->a0);
+		if (status != RMI_BUSY && status != RMI_BLOCKED)
+			break;
+		if (status == RMI_BLOCKED)
+			i++;
+		cpu_relax();
+	}
+}
+
+unsigned long rmi_feat_reg(unsigned long index);
+
+#endif
-- 
2.43.0

[PATCH v19 3/7] firmware: arm_rmm: Configure the RMM with the host's page size

[Suzuki K Poulose]

RMM v2.0 brings the ability to set the RMM's granule size. Check the
feature registers and configure the RMM so that it matches the host's
page size. This means that operations can be done with a granularity
equal to PAGE_SIZE.

Signed-off-by: Steven Price <steven.price@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
---
 Changes since v18:
  * Move the rmi_config_set closer to rmi_configure, drop the comment
  * Use __free() magic for rmm_config object
 Changes since v17:
  * Move rmi_config_set() out of the header file.
  * Print the error message for rmi_config_set if it fails
 Changes since v15:
  * Actually check the feature register for the host's page-size support.
 Changes since v14:
  * Move the implementation into drivers/firmware/arm_rmm.
 Changes since v13:
  * Moved out of KVM.
---
 drivers/firmware/arm_rmm/rmi.c | 70 ++++++++++++++++++++++++++++++++++
 1 file changed, 70 insertions(+)

diff --git a/drivers/firmware/arm_rmm/rmi.c b/drivers/firmware/arm_rmm/rmi.c
index 3baba931f92e4..c9ea964fd9081 100644
--- a/drivers/firmware/arm_rmm/rmi.c
+++ b/drivers/firmware/arm_rmm/rmi.c
@@ -84,6 +84,72 @@ unsigned long rmi_feat_reg(unsigned long index)
 }
 EXPORT_SYMBOL_GPL(rmi_feat_reg);
 
+static int rmi_rmm_config_set(unsigned long cfg_ptr)
+{
+	struct arm_smccc_1_2_regs regs = {
+		SMC_RMI_RMM_CONFIG_SET, cfg_ptr,
+	};
+
+	rmi_smccc_invoke(&regs);
+
+	return regs.a0;
+}
+
+static int rmi_configure(void)
+{
+	unsigned long granule_feature;
+	unsigned long granule_size;
+	int ret = 0;
+
+	switch (PAGE_SIZE) {
+	case SZ_4K:
+		granule_size = RMI_GRANULE_SIZE_4KB;
+		granule_feature = RMI_FEATURE_REGISTER_1_RMI_GRAN_SZ_4KB;
+		break;
+	case SZ_16K:
+		granule_size = RMI_GRANULE_SIZE_16KB;
+		granule_feature = RMI_FEATURE_REGISTER_1_RMI_GRAN_SZ_16KB;
+		break;
+	case SZ_64K:
+		granule_size = RMI_GRANULE_SIZE_64KB;
+		granule_feature = RMI_FEATURE_REGISTER_1_RMI_GRAN_SZ_64KB;
+		break;
+	default:
+		BUILD_BUG();
+	}
+
+	if (!(rmi_feat_reg(1) & granule_feature)) {
+		pr_err("RMM does not support %luKB granules\n",
+		       PAGE_SIZE >> 10);
+		return -ENXIO;
+	}
+
+	struct rmm_config *config __free(free_page) =
+		(struct rmm_config *)get_zeroed_page(GFP_KERNEL);
+
+	if (!config) {
+		pr_err("Unable to allocate memory for RMM config\n");
+		return -ENOMEM;
+	}
+
+	config->rmi_granule_size = granule_size;
+
+	/*
+	 * For now we set the tracking_region_size to 0 which is the only option
+	 * for 4KB PAGE_SIZE (1GB for 4KB PAGE_SIZE, 32MB/512MB for 16KB/64KB).
+	 * TODO: Support other tracking sizes via Kconfig option for other
+	 * PAGE_SIZES
+	 */
+	config->tracking_region_size = 0;
+
+	ret = rmi_rmm_config_set(virt_to_phys(config));
+	if (ret) {
+		pr_err("RMM config set failed (%d)\n", ret);
+		ret = -EINVAL;
+	}
+
+	return ret;
+}
 
 static int __init arm64_init_rmi(void)
 {
@@ -98,6 +164,10 @@ static int __init arm64_init_rmi(void)
 	if (ret)
 		return ret;
 
+	ret = rmi_configure();
+	if (ret)
+		return ret;
+
 	return 0;
 }
 
-- 
2.43.0

[PATCH v19 4/7] firmware: arm_rmm: Add support for SRO

[Suzuki K Poulose]

From: Steven Price <steven.price@arm.com>

RMM v2.0 introduces the concept of "Stateful RMI Operations" (SRO). This
means that an SMC can return with an operation still in progress. The
host is expected to continue the operation until it reaches a conclusion
(either success or failure). During this process the RMM can request
additional memory ('donate') or hand memory back to the host
('reclaim'). The host can request an in progress operation is cancelled,
but still continue the operation until it has completed (otherwise the
incomplete operation may cause future RMM operations to fail).

The SRO is tracked using a struct rmi_sro_state object which keeps track
of any memory which has been allocated but not yet consumed by the RMM
or reclaimed from the RMM. This allows the memory to be reused in a
future request within the same operation. It will also permit an
operation to be done in a context where memory allocation may be
difficult (e.g. atomic context) with the option to abort the operation
and retry the memory allocation outside of the atomic context. The
memory stored in the struct rmi_sro_state object can then be reused on
the subsequent attempt.

Wrappers for SRO RMI commands are also provided here because they depend
on the rmi_sro_execute() implementation added by this patch.
Delegate/undelegate handles are also added here because they now use the
SRO/stateful command infrastructure and are also used for the memory
DONATE/RECLAIM flows.

Signed-off-by: Steven Price <steven.price@arm.com>
Co-developed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
---
 v19:
  * Clamp the mem donate request count to RMI_MAX_ADDR_LIST to prevent overflow
    for non_contig requests
  * Donate gathered memory when sro list runs out of space for non_contig case
  * Add comments for rmi_delegate_range(), rmi_free_delegated_page()
  * Fix handling of buggy RMM for rmi_delegate_range()
  * Move rmi_granule_*delegate_range() closer to their callers.
  * Clarify the requirements for rmi_granule_delegate_range()
  * Fix return result to -ENXIO if the MEM_OP is unknown
  * Handle unsupported RMI_OP_MEM_CONDITIONAL
  * Rename "out" label to "mem_donate"
  * Switch to use while loop for rmi_sro_donate_noncontig(), add comments
    where we gather the cached entries
  * If we don't have capacity in the SRO object, try with what we managed to
    collect for non-contiguous requests
  * Switch to for() loop for allocation of granules
  * Add comment, make code reader friendly for the caching the remaining
    entries after the memory donate
  * Add documentation for rmi_sro_execute()

 v18:
  * Prevent overflow for donated_granules output from buggy RMM
  * Handle corrupted addr_count in the sro
  * Avoid spilling literal pools on stack with sro initialisation
  * Handle buggy RMM when the out_top is not changed with RMI_SUCCESS
    for delegat/undelegate range calls
  * Rename free_delegated_page => rmi_free_delegated_page
  * Rename donate_req_to_unit_size => donate_req_to_block_size
  * Introduce rmi_addr_block_size_to_bytes() helper to convert a RmiAddrBlockSize
    encoding used in RMI_DONATE_REQ and RMI_ADDR_RANGE Descriptors, replaces
    donate_req_to_unit_size()
  * Rename unit_size => block_size_fld, unit_size_bytes => block_size etc.
  * Explicitly check for MEM_CONTIG/CAN_CANCEL fields to match the RMM spec values.
  * Rename free_delegated_page => rmi_free_delegated_page()
  * Drop RMI_BUSY, RMI_BLOCKED checks from rmi_*delegate_range as they are already
    handled by the rmi_smccc_invoke() used by the SRO.
  * Add a helper to free an address range entry, which may be partially consumed.
  * Ensure RMI_OP_RECLAIM output is valid before consumption
 v17:
  * Handle buggy RMM firmware to avoid looping forever for non-cancellable SROs.
  * Add comment (for the AI agents) to clarify that all memory donating SROs are
    cancellable.
 v16:
  * Wrappers for realm guests split into a separate patch.
  * Better support for cancellation - previously a cancelled operation
    could be treated as successful.
  * Consistently use a signed type for wrapper return values so that
    Linux error codes can be returned as well as RMI return values.
 v15:
  * Wrappers for SRO RMI functions are provided in this patch due to
    their dependency on the SRO infrastructure.
  * Fold the range delegate/undelegate wrappers into this patch because
    they depend on the stateful command infrastructure.
  * Add cpu_relax() calls when RMI_BUSY/RMI_BLOCKED is returned.
  * Various fixes.
 v14:
  * SRO support has improved although is still not fully complete. The
    infrastructure has been moved out of KVM.
---
 drivers/firmware/arm_rmm/rmi.c | 666 +++++++++++++++++++++++++++++++++
 include/linux/arm-rmi-cmds.h   |  41 ++
 2 files changed, 707 insertions(+)

diff --git a/drivers/firmware/arm_rmm/rmi.c b/drivers/firmware/arm_rmm/rmi.c
index c9ea964fd9081..035f21d3f26b6 100644
--- a/drivers/firmware/arm_rmm/rmi.c
+++ b/drivers/firmware/arm_rmm/rmi.c
@@ -14,6 +14,672 @@
 /* RMM defines RmiFeatureRegister0 to RmiFeatureRegister5. */
 static unsigned long rmi_feat_reg_cache[5] __ro_after_init;
 
+/**
+ * rmi_granule_range_undelegate() - Undelegate a range of granules
+ * @base: Base PA of the target range
+ * @top: Top PA of the target range
+ * @out_top: Returns the top PA of range whose state is undelegated
+ *
+ * Undelegate a range of granules to allow use by the normal world. Will fail
+ * if the granules are in use by RMM. RMM can ignore granules that are already
+ * undelegated and thus is safe to be called on a range with a mix of delegated
+ * and undelegated granules.
+ *
+ * Return: 0 on success, positive RMI result code or negative Linux error code
+ */
+static inline long rmi_granule_range_undelegate(unsigned long base,
+						unsigned long top,
+						unsigned long *out_top)
+{
+	struct arm_smccc_1_2_regs regs = {
+		SMC_RMI_GRANULE_RANGE_UNDELEGATE, base, top
+	};
+	long ret = rmi_sro_execute(&regs);
+
+	if (ret == RMI_SUCCESS && out_top)
+		*out_top = regs.a1;
+
+	return ret;
+}
+
+int rmi_undelegate_range(phys_addr_t phys,
+			 unsigned long size)
+{
+	long ret = 0;
+	unsigned long top = phys + size;
+	unsigned long out_top;
+
+	while (phys < top) {
+		ret = rmi_granule_range_undelegate(phys, top, &out_top);
+
+		if (ret == RMI_SUCCESS) {
+			/* Buggy RMM ? Let the caller leak the pages */
+			if (WARN_ON(out_top <= phys))
+				return -ENXIO;
+			phys = out_top;
+		} else {
+			break;
+		}
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(rmi_undelegate_range);
+
+/**
+ * rmi_granule_range_delegate() - Delegate granules
+ * @base: PA of the first granule of the range
+ * @top: PA of the first granule after the range
+ * @out_top: PA of the first granule not delegated
+ *
+ * Delegate a range of granule for use by the realm world. If the entire range
+ * was delegated then @out_top == @top, otherwise the function should be called
+ * again with @base == @out_top.
+ *
+ * Return: 0 on success, positive RMI result code or negative Linux error code
+ */
+static long rmi_granule_range_delegate(unsigned long base,
+				       unsigned long top,
+				       unsigned long *out_top)
+{
+	struct arm_smccc_1_2_regs regs = {
+		SMC_RMI_GRANULE_RANGE_DELEGATE, base, top
+	};
+	long ret = rmi_sro_execute(&regs);
+
+	if (ret == RMI_SUCCESS && out_top)
+		*out_top = regs.a1;
+
+	return ret;
+}
+
+/*
+ * rmi_delegate_range: Delegate a physically contiguous range.
+ * We iterate over the range until we hit an error. So we may
+ * return an error, but with a partially delegated range. The
+ * caller must always look at the @out_phys to figure out, how
+ * much progress was made.
+ *
+ * @phys:	Base of the physical address range
+ * @size:	Size of the physical address range
+ * @out_phys:	Top of the range that was completed. This is always
+ *		valid, irrespective of the result.
+ *
+ * Returns RMI_SUCCESS on successful completion. Otherwise, returns
+ * the Linux error number or the RMI status code as described
+ * by the RMM spec for RMI_GRANULE_DELEGATE_RANGE or RMI_BLOCKED.
+ */
+int rmi_delegate_range(phys_addr_t phys,
+		       unsigned long size,
+		       phys_addr_t *out_phys)
+{
+	long ret = 0;
+	unsigned long top = phys + size;
+	unsigned long out_top;
+
+	while (phys < top) {
+		ret = rmi_granule_range_delegate(phys, top, &out_top);
+
+		if (ret == RMI_SUCCESS) {
+			/*
+			 * Buggy RMM ? Let the caller handle the failure.
+			 * We can't know how far the RMM delegated in this
+			 * iteration, so we return the best known good limit.
+			 * RMM can deal with granules already in "undelegated"
+			 * in a given range. So, it is fine for the caller to
+			 * try the range we return.
+			 */
+			if (WARN_ON(out_top <= phys)) {
+				ret = -ENXIO;
+				break;
+			}
+			phys = out_top;
+		} else {
+			break;
+		}
+	}
+
+	if (out_phys)
+		*out_phys = phys;
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(rmi_delegate_range);
+
+/*
+ * Convert the RmiAddrBlockSize to actual size. This is used in RmiDonateReq
+ * and RmiAddrRangeDesc*.
+ */
+static unsigned long rmi_addr_block_size_to_bytes(unsigned long block_size_fld)
+{
+	return BIT(ARM64_HW_PGTABLE_LEVEL_SHIFT(3 - block_size_fld));
+}
+
+/*
+ * free_addr_range: Free memory described by the address range entry, which may
+ *		    be partially consumed by RMM.
+ *
+ * @entry: RMI_ADDR_RANGE descriptor
+ * @consumed_size: Page aligned size consumed by the RMM from the address range.
+ *
+ * If the state of the address is DELEGATED, undelegate it back, before freeing.
+ * Leaks the memory if we cannot undelegate the range.
+ */
+static void free_addr_range(unsigned long entry, unsigned long consumed_size)
+{
+	unsigned long phys = RMI_ADDR_RANGE_ADDR(entry);
+	unsigned long block_size_fld = RMI_ADDR_RANGE_BLOCK_SIZE(entry);
+	unsigned long count = RMI_ADDR_RANGE_COUNT(entry);
+	unsigned long state = RMI_ADDR_RANGE_STATE(entry);
+	unsigned long size = rmi_addr_block_size_to_bytes(block_size_fld) * count;
+
+	WARN_ON(!PAGE_ALIGNED(phys) || !PAGE_ALIGNED(consumed_size));
+
+	/* We shouldn't see this in reclaim path, leak it for now  */
+	if (WARN_ON(state == RMI_OP_MEM_CONDITIONAL))
+		return;
+
+	/* Adjust the address and size for partially consumed entry */
+	phys += consumed_size;
+	size -= consumed_size;
+	/*
+	 * Undelegate the pages back if required. If we can't
+	 * change them back, leak the pages.
+	 */
+	if (state == RMI_OP_MEM_DELEGATED &&
+	    WARN_ON(rmi_undelegate_range(phys, size)))
+		return;
+	free_pages_exact(phys_to_virt(phys), size);
+}
+
+static void rmi_op_continue(unsigned long sro_handle, unsigned long flags,
+			    struct arm_smccc_1_2_regs *out_regs)
+{
+	*out_regs = (struct arm_smccc_1_2_regs) {
+		SMC_RMI_OP_CONTINUE, sro_handle, flags
+	};
+
+	rmi_smccc_invoke(out_regs);
+}
+
+static void rmi_op_cancel(unsigned long sro_handle,
+			  struct arm_smccc_1_2_regs *out_regs)
+{
+	*out_regs = (struct arm_smccc_1_2_regs) {
+		SMC_RMI_OP_CANCEL, sro_handle
+	};
+
+	rmi_smccc_invoke(out_regs);
+}
+
+static void rmi_op_mem_donate(unsigned long sro_handle, unsigned long list_addr,
+			      unsigned long list_count, unsigned long flags,
+			      struct arm_smccc_1_2_regs *out_regs)
+{
+	*out_regs = (struct arm_smccc_1_2_regs) {
+		SMC_RMI_OP_MEM_DONATE, sro_handle, list_addr, list_count, flags
+	};
+
+	/*
+	 * The output donated count (a1) is always valid, irrespective
+	 * of the return result. i.e., 0 if there was an error
+	 */
+	rmi_smccc_invoke(out_regs);
+}
+
+static void rmi_op_mem_reclaim(unsigned long sro_handle,
+			       unsigned long list_addr,
+			       unsigned long list_count,
+			       struct arm_smccc_1_2_regs *out_regs)
+{
+	*out_regs = (struct arm_smccc_1_2_regs) {
+		SMC_RMI_OP_MEM_RECLAIM, sro_handle, list_addr, list_count
+	};
+
+	rmi_smccc_invoke(out_regs);
+}
+
+/*
+ * rmi_free_delegated_page: Undelegate and free a page that has been previously
+ * delegated to the Realm world. If we are unable to undelegate it, the page is
+ * leaked.
+ * NOTE: Do not use this helper if the page could be concurrently operated by
+ * another thread, as it may get leaked if the undelegation fails due to RMI_BLOCKED
+ */
+int rmi_free_delegated_page(phys_addr_t phys)
+{
+	if (WARN_ON_ONCE(rmi_undelegate_page(phys))) {
+		/* Undelegate failed: leak the page */
+		return -EBUSY;
+	}
+
+	free_page((unsigned long)phys_to_virt(phys));
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(rmi_free_delegated_page);
+
+static int rmi_sro_ensure_capacity(struct rmi_sro_state *sro,
+				   unsigned long count)
+{
+	if (WARN_ON_ONCE(sro->addr_count > RMI_MAX_ADDR_LIST))
+		return -EOVERFLOW;
+
+	if (count > RMI_MAX_ADDR_LIST - sro->addr_count)
+		return -ENOSPC;
+
+	return 0;
+}
+
+static int rmi_sro_donate_contig(struct rmi_sro_state *sro,
+				 unsigned long sro_handle,
+				 unsigned long donatereq,
+				 struct arm_smccc_1_2_regs *out_regs,
+				 gfp_t gfp)
+{
+	unsigned long block_size_fld = RMI_DONATE_BLOCK_SIZE(donatereq);
+	unsigned long block_size = rmi_addr_block_size_to_bytes(block_size_fld);
+	unsigned long count = RMI_DONATE_COUNT(donatereq);
+	unsigned long state = RMI_DONATE_STATE(donatereq);
+	unsigned long size = block_size * count;
+	unsigned long addr_range;
+	unsigned long donated_granules;
+	unsigned long donated_size;
+	int ret;
+	void *virt;
+	phys_addr_t phys;
+
+	/*
+	 * The RMM specification requires contiguous allocations are always a
+	 * power of 2
+	 */
+	if (WARN_ON_ONCE(!is_power_of_2(size)))
+		return -EINVAL;
+
+	/* Reuse the cached address range if we have one */
+	for (int i = 0; i < sro->addr_count; i++) {
+		unsigned long entry = sro->addr_list[i];
+
+		if (RMI_ADDR_RANGE_BLOCK_SIZE(entry) == block_size_fld &&
+		    RMI_ADDR_RANGE_COUNT(entry) == count &&
+		    RMI_ADDR_RANGE_STATE(entry) == state &&
+		    IS_ALIGNED(RMI_ADDR_RANGE_ADDR(entry), size)) {
+			sro->addr_count--;
+			swap(sro->addr_list[sro->addr_count],
+			     sro->addr_list[i]);
+
+			goto mem_donate;
+		}
+	}
+
+	ret = rmi_sro_ensure_capacity(sro, 1);
+	if (ret)
+		return ret;
+
+	virt = alloc_pages_exact(size, gfp);
+	if (!virt)
+		return -ENOMEM;
+	phys = virt_to_phys(virt);
+
+	if (state == RMI_OP_MEM_DELEGATED) {
+		phys_addr_t delegated_phys;
+
+		if (rmi_delegate_range(phys, size, &delegated_phys)) {
+			if (!rmi_undelegate_range(phys, delegated_phys - phys))
+				free_pages_exact(virt, size);
+			return -ENXIO;
+		}
+	}
+
+	addr_range = phys & RMI_ADDR_RANGE_ADDR_MASK;
+	FIELD_MODIFY(RMI_ADDR_RANGE_BLOCK_SIZE_MASK, &addr_range, block_size_fld);
+	FIELD_MODIFY(RMI_ADDR_RANGE_COUNT_MASK, &addr_range, count);
+	FIELD_MODIFY(RMI_ADDR_RANGE_STATE_MASK, &addr_range, state);
+
+	sro->addr_list[sro->addr_count] = addr_range;
+
+mem_donate:
+	rmi_op_mem_donate(sro_handle,
+			  virt_to_phys(&sro->addr_list[sro->addr_count]), 1,
+			  0, out_regs);
+	donated_granules = out_regs->a1;
+
+	if (WARN_ON(donated_granules > (size >> PAGE_SHIFT)))
+		donated_granules = (size >> PAGE_SHIFT);
+
+	donated_size = donated_granules << PAGE_SHIFT;
+
+	/* All granules consumed by the RMM */
+	if (donated_size == size)
+		return 0;
+	/* No granules were consumed by the RMM, cache them */
+	if (donated_granules == 0) {
+		sro->addr_count++;
+		return 0;
+	}
+
+	/* The granules were partially consumed, reclaim the unused ones. */
+	free_addr_range(sro->addr_list[sro->addr_count], donated_size);
+
+	return 0;
+}
+
+static int rmi_sro_donate_noncontig(struct rmi_sro_state *sro,
+				    unsigned long sro_handle,
+				    unsigned long donatereq,
+				    struct arm_smccc_1_2_regs *out_regs,
+				    gfp_t gfp)
+{
+	unsigned long block_size_fld = RMI_DONATE_BLOCK_SIZE(donatereq);
+	unsigned long block_size = rmi_addr_block_size_to_bytes(block_size_fld);
+	unsigned long count = RMI_DONATE_COUNT(donatereq);
+	unsigned long state = RMI_DONATE_STATE(donatereq);
+	unsigned long found = 0;
+	unsigned long donated_granules;
+	unsigned long granules_per_block = block_size >> PAGE_SHIFT;
+	unsigned long consumed_blocks;
+	int addr_list_start = sro->addr_count;
+	int ret, i;
+
+	/*
+	 * Clamp the number of entries to the maximum we can do in one go.
+	 * The RMM can request  the remaining in the next iteration.
+	 */
+	if (count > RMI_MAX_ADDR_LIST)
+		count = RMI_MAX_ADDR_LIST;
+
+	/* Gather the suitable entries to the end of the list */
+	i = 0;
+	while (i <  addr_list_start && found < count) {
+		unsigned long entry = sro->addr_list[i];
+
+		if (RMI_ADDR_RANGE_BLOCK_SIZE(entry) == block_size_fld &&
+		    RMI_ADDR_RANGE_COUNT(entry) == 1 &&
+		    RMI_ADDR_RANGE_STATE(entry) == state) {
+			addr_list_start--;
+			swap(sro->addr_list[addr_list_start],
+			     sro->addr_list[i]);
+			found++;
+			/* Continue from the swapped in entry */
+			continue;
+		}
+		/* skip past the entry */
+		i++;
+	}
+
+	ret = rmi_sro_ensure_capacity(sro, count - found);
+	if (ret) {
+		/* If we have found some entries, donate them and try again */
+		if (found)
+			goto mem_donate;
+		/* Otherwise free up the list and start again */
+		rmi_sro_free(sro);
+		/* Reset the addr_list_start to match sro->addr_count */
+		addr_list_start = 0;
+	}
+
+	for (; found < count; found++) {
+		unsigned long addr_range;
+		void *virt = alloc_pages_exact(block_size, gfp);
+		phys_addr_t phys;
+
+		if (!virt)
+			return -ENOMEM;
+
+		phys = virt_to_phys(virt);
+
+		if (state == RMI_OP_MEM_DELEGATED) {
+			phys_addr_t delegated_phys;
+
+			if (rmi_delegate_range(phys, block_size, &delegated_phys)) {
+				if (!rmi_undelegate_range(phys, delegated_phys - phys))
+					free_pages_exact(virt, block_size);
+				return -ENXIO;
+			}
+		}
+
+		addr_range = phys & RMI_ADDR_RANGE_ADDR_MASK;
+		FIELD_MODIFY(RMI_ADDR_RANGE_BLOCK_SIZE_MASK, &addr_range, block_size_fld);
+		FIELD_MODIFY(RMI_ADDR_RANGE_COUNT_MASK, &addr_range, 1);
+		FIELD_MODIFY(RMI_ADDR_RANGE_STATE_MASK, &addr_range, state);
+
+		sro->addr_list[sro->addr_count++] = addr_range;
+	}
+
+mem_donate:
+	rmi_op_mem_donate(sro_handle,
+			  virt_to_phys(&sro->addr_list[addr_list_start]),
+			  found, 0, out_regs);
+
+	donated_granules = out_regs->a1;
+	/*
+	 * The RMM shouldn't report more granules than we provided, but clamp
+	 * just in case.
+	 */
+	if (WARN_ON_ONCE(donated_granules > found * granules_per_block))
+		donated_granules = found * granules_per_block;
+
+	/*
+	 * The RMM reports the consumed memory in terms of granules, but we
+	 * track in the address lists in block-sized ranges. So divide to get
+	 * the number of (complete) consumed blocks.
+	 */
+	consumed_blocks = donated_granules / granules_per_block;
+	if (donated_granules % granules_per_block) {
+		/*
+		 * A block has been partially consumed, the start is owned by
+		 * the RMM, the tail is owned by the host
+		 */
+		unsigned long entry =
+			sro->addr_list[addr_list_start + consumed_blocks];
+		unsigned long donated_size =
+			(donated_granules % granules_per_block) << PAGE_SHIFT;
+
+		free_addr_range(entry, donated_size);
+		/*
+		 * This block is now fully 'consumed' (either held by the RMM or
+		 * freed)
+		 */
+		consumed_blocks++;
+	}
+
+	/*
+	 * Keep just the blocks the RMM didn't use in addr_list
+	 * RMM claimed consumed_blocks entries from addr_list_start.
+	 * Move the entries left out at the end i.e.,
+	 * [ addr_list_start + consumed_blocks, addr_list_start + found)
+	 * to the rest of the valid entries and adjust the addr_count to
+	 * reflect the available entries.
+	 */
+	for (int i = 0, src = addr_list_start + consumed_blocks;
+		i < found - consumed_blocks; i++)
+		sro->addr_list[addr_list_start + i] = sro->addr_list[src + i];
+
+	sro->addr_count -= consumed_blocks;
+
+	return 0;
+}
+
+static int rmi_sro_donate(struct rmi_sro_state *sro,
+			  unsigned long sro_handle,
+			  unsigned long donatereq,
+			  struct arm_smccc_1_2_regs *regs,
+			  gfp_t gfp)
+{
+	if (WARN_ON_ONCE(!RMI_DONATE_COUNT(donatereq)))
+		return -EINVAL;
+
+	/*
+	 * We do not support RMI_OP_MEM_CONDITIONAL yet. This is only required
+	 * for use in RMI_GRANULE_TRACKING_SET, which we don't support yet.
+	 */
+	if (WARN_ON_ONCE(RMI_DONATE_STATE(donatereq) == RMI_OP_MEM_CONDITIONAL))
+		return -EINVAL;
+
+	if (RMI_DONATE_CONTIG(donatereq) == RMI_OP_MEM_CONTIG)
+		return rmi_sro_donate_contig(sro, sro_handle, donatereq, regs, gfp);
+	else
+		return rmi_sro_donate_noncontig(sro, sro_handle, donatereq, regs, gfp);
+}
+
+static int rmi_sro_reclaim(struct rmi_sro_state *sro,
+			   unsigned long sro_handle,
+			   struct arm_smccc_1_2_regs *out_regs)
+{
+	unsigned long capacity;
+
+	/*
+	 * We don't do a partial free of the entries. So for
+	 * now free the entire address list as we prepare
+	 * to reclaim more from the RMM.
+	 */
+	if (rmi_sro_ensure_capacity(sro, 1))
+		rmi_sro_free(sro);
+
+	capacity = RMI_MAX_ADDR_LIST - sro->addr_count;
+
+	rmi_op_mem_reclaim(sro_handle,
+			   virt_to_phys(&sro->addr_list[sro->addr_count]),
+			   capacity, out_regs);
+
+	/*
+	 * RMI_OP_MEM_RECLAIM always return RMI_INCOMPLETE, except when the
+	 * input parameters were invalid.
+	 */
+	if (WARN_ON_ONCE(RMI_RESULT_STATUS(out_regs->a0) != RMI_INCOMPLETE))
+		return -EINVAL;
+	if (WARN_ON_ONCE(out_regs->a1 > capacity))
+		out_regs->a1 = capacity;
+
+	sro->addr_count += out_regs->a1;
+
+	return 0;
+}
+
+void rmi_sro_free(struct rmi_sro_state *sro)
+{
+	/* Handle the worse */
+	if (WARN_ON(sro->addr_count < 0))
+		return;
+
+	if (WARN_ON(sro->addr_count > RMI_MAX_ADDR_LIST))
+		sro->addr_count = RMI_MAX_ADDR_LIST;
+
+	for (int i = 0; i < sro->addr_count; i++)
+		free_addr_range(sro->addr_list[i], 0);
+
+	sro->addr_count = 0;
+}
+EXPORT_SYMBOL_GPL(rmi_sro_free);
+
+long rmi_sro_memxfer_execute(struct rmi_sro_state *sro, gfp_t gfp)
+{
+	struct arm_smccc_1_2_regs *regs = &sro->regs;
+	bool cancelled = false;
+	unsigned long sro_handle;
+
+	rmi_smccc_invoke(regs);
+
+	sro_handle = regs->a1;
+	while (RMI_RESULT_STATUS(regs->a0) == RMI_INCOMPLETE) {
+		bool can_cancel = RMI_RESULT_CAN_CANCEL(regs->a0) == RMI_OP_CAN_CANCEL;
+		int ret = 0;
+
+		switch (RMI_RESULT_MEMREQ(regs->a0)) {
+		case RMI_OP_MEM_REQ_NONE:
+			rmi_op_continue(sro_handle, RMI_CONTINUE_KEEP_GOING,
+					regs);
+			break;
+		case RMI_OP_MEM_REQ_DONATE:
+			ret = rmi_sro_donate(sro, sro_handle, regs->a2, regs,
+					     gfp);
+			break;
+		case RMI_OP_MEM_REQ_RECLAIM:
+			ret = rmi_sro_reclaim(sro, sro_handle, regs);
+			break;
+		default:
+			WARN_ON_ONCE(1);
+			ret = -ENXIO;
+			break;
+		}
+
+		if (ret) {
+			/*
+			 * All memory donating SROs must be cancellable. So a
+			 * failure in memory allocation shouldn't be an issue.
+			 * However, if we encounter a random failure (e.g.,
+			 * buggy RMM), don't loop forever, just give up.
+			 */
+			if (WARN_ON_ONCE(!can_cancel))
+				return ret;
+			/*
+			 * If we have already cancelled, and came back here due
+			 * to an error in MEMREQ, then there is no point
+			 * in going in loops.
+			 */
+			if (WARN_ON_ONCE(cancelled))
+				break;
+			rmi_op_cancel(sro_handle, regs);
+			cancelled = true;
+
+			if (WARN_ON_ONCE(RMI_RESULT_STATUS(regs->a0) != RMI_INCOMPLETE))
+				return ret;
+		}
+	}
+
+	if (cancelled)
+		return -ECANCELED;
+
+	return regs->a0;
+}
+EXPORT_SYMBOL_GPL(rmi_sro_memxfer_execute);
+
+/*
+ * rmi_sro_execute: Execute an RMI command that is Stateful but not memory
+ * tranfserring. Takes regs, filled with the FIDs and the arguments in place.
+ *
+ * Returns :
+ *  -ECANCELLED - If the operation had to be aborted and SRO was cancellable.
+ *  Otherwise, returns the result of the RMI command.
+ */
+long rmi_sro_execute(struct arm_smccc_1_2_regs *regs)
+{
+	bool cancelled = false;
+	unsigned long sro_handle = regs->a1;
+
+	rmi_smccc_invoke(regs);
+
+	sro_handle = regs->a1;
+	while (RMI_RESULT_STATUS(regs->a0) == RMI_INCOMPLETE) {
+		bool can_cancel = RMI_RESULT_CAN_CANCEL(regs->a0) == RMI_OP_CAN_CANCEL;
+
+		switch (RMI_RESULT_MEMREQ(regs->a0)) {
+		case RMI_OP_MEM_REQ_NONE:
+			rmi_op_continue(sro_handle, RMI_CONTINUE_KEEP_GOING,
+					regs);
+			break;
+		default:
+			WARN_ON_ONCE(1);
+			if (!can_cancel)
+				return regs->a0;
+			/*
+			 * We can't get here normally, but handle this anyway
+			 * for a buggy RMM implementation.
+			 */
+			if (cancelled)
+				return -ECANCELED;
+			rmi_op_cancel(sro_handle, regs);
+			cancelled = true;
+		}
+	}
+
+	if (cancelled)
+		return -ECANCELED;
+
+	return regs->a0;
+}
+EXPORT_SYMBOL_GPL(rmi_sro_execute);
+
 static int rmi_check_version(void)
 {
 	unsigned short version_major, version_minor;
diff --git a/include/linux/arm-rmi-cmds.h b/include/linux/arm-rmi-cmds.h
index 5c6c563c81555..b03974fd8168c 100644
--- a/include/linux/arm-rmi-cmds.h
+++ b/include/linux/arm-rmi-cmds.h
@@ -8,9 +8,19 @@
 
 #include <linux/arm-smccc-rmi.h>
 #include <linux/bug.h>
+#include <linux/gfp.h>
 #include <linux/processor.h>
+#include <linux/string.h>
 #include <linux/types.h>
 
+#define RMI_MAX_ADDR_LIST	256
+
+struct rmi_sro_state {
+	struct arm_smccc_1_2_regs regs;
+	int addr_count;
+	unsigned long addr_list[RMI_MAX_ADDR_LIST];
+};
+
 #define RMM_BLOCKED_RETRY_COUNT		2
 /*
  * rmi_smccc_invoke: Invoke the RMI call and return the results, retrying the
@@ -45,4 +55,35 @@ static inline void rmi_smccc_invoke(struct arm_smccc_1_2_regs *regs)
 
 unsigned long rmi_feat_reg(unsigned long index);
 
+int rmi_delegate_range(phys_addr_t phys, unsigned long size,
+		       phys_addr_t *out_phys);
+int rmi_undelegate_range(phys_addr_t phys, unsigned long size);
+int rmi_free_delegated_page(phys_addr_t phys);
+
+static inline int rmi_delegate_page(phys_addr_t phys)
+{
+	return rmi_delegate_range(phys, PAGE_SIZE, NULL);
+}
+
+static inline int rmi_undelegate_page(phys_addr_t phys)
+{
+	return rmi_undelegate_range(phys, PAGE_SIZE);
+}
+
+long rmi_sro_memxfer_execute(struct rmi_sro_state *sro, gfp_t gfp);
+void rmi_sro_free(struct rmi_sro_state *sro);
+long rmi_sro_execute(struct arm_smccc_1_2_regs *regs);
+
+/*
+ * Resetting the addr_count is sufficient to ignore the addr_list contents.
+ */
+#define rmi_sro_memxfer_cmd(sro, gfp, ...) ({				\
+	struct rmi_sro_state *__sro = (sro);				\
+	__sro->addr_count = 0;						\
+	__sro->regs = (struct arm_smccc_1_2_regs){ __VA_ARGS__ };	\
+	long __ret = rmi_sro_memxfer_execute(__sro, gfp);		\
+	rmi_sro_free(__sro);						\
+	__ret;								\
+})
+
 #endif
-- 
2.43.0

[PATCH v19 5/7] firmware: arm_rmm: Activate the RMM

[Suzuki K Poulose]

From: Steven Price <steven.price@arm.com>

Activate the RMM after the basic configuration. This is a memory
transferring stateful operation.

Reviewed-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@oss.qualcomm.com>
Signed-off-by: Steven Price <steven.price@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
---
Changes since v17:
 * Inline RMM_ACTIVATE command and remove the definitions from arm-rmi-cmds.h
 * Use scope-based cleanup to free sro object
Changes since v16:
 * Split into a new patch
---
 drivers/firmware/arm_rmm/rmi.c | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/drivers/firmware/arm_rmm/rmi.c b/drivers/firmware/arm_rmm/rmi.c
index 035f21d3f26b6..0859f256e192b 100644
--- a/drivers/firmware/arm_rmm/rmi.c
+++ b/drivers/firmware/arm_rmm/rmi.c
@@ -834,7 +834,18 @@ static int __init arm64_init_rmi(void)
 	if (ret)
 		return ret;
 
-	return 0;
+	/* Activate the RMM */
+	struct rmi_sro_state *sro __free(kfree) = kmalloc_obj(*sro);
+	if (!sro)
+		return -ENOMEM;
+
+	ret = rmi_sro_memxfer_cmd(sro, GFP_KERNEL, SMC_RMI_RMM_ACTIVATE);
+	if (ret) {
+		pr_err("RMM activate failed (%d)\n", ret);
+		ret = ret < 0 ? ret : -ENXIO;
+	}
+
+	return ret;
 }
 
 /*
-- 
2.43.0

[PATCH v19 6/7] firmware: arm_rmm: Ensure the RMM has GPT entries for memory

[Suzuki K Poulose]

From: Steven Price <steven.price@arm.com>

The RMM maintains the state of all the granules in the system to make
sure that the host is abiding by the rules. This state can be maintained
at different granularity, per page (TRACKING_FINE) or per region
(TRACKING_COARSE or TRACKING_INTERMEDIATE). The region size depends on the
underlying "RMI_GRANULE_SIZE". For a "coarse"/"intermediate" region,
all pages in the region must be of the same state, this implies we need to
have "fine" tracking for DRAM, so that we can delegate individual pages.

For now we only support a statically carved out memory for tracking
granules for the "fine" regions. This can be extended in the future to
allow modifying the tracking granularity and remove the need for a
static allocation by the firmware.

Similarly, the firmware may create L0 GPT entries describing the total
address space. But if we change the "PAS" (Physical Address Space) of a
granule, then the firmware may need to create L1 tables to track the PAS
at a finer granularity. Linux therefore checks if the platform firmware
manages the PAR region. i.e., the firmware is in charge of managing the
L1 GPTs (creation and the required memory for the GPT tables - via static
carveouts) without host intervention. Support for dynamic GPT creation by
the host will be added later.

If the firmware requires us to manage the tracking or GPT memory,
deactivate the RMM and reclaim any memory donated at RMM activation.

Apply the same checks when hotplugged memory is brought online.

Signed-off-by: Steven Price <steven.price@arm.com>
[ Switch to RMI_GPT_L1_INFO for checking GPTs and deactivate RMM ]
Co-developed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
---
 Changes since v19:
     * Avoid mixing gotos with __free cleanups for arm64_init_rmi()
 Changes since v18:
     * Handle buggy RMM to make forward progress for RMI_GPT_INFO and
       RMI_GRANULE_TRACKING_GET
     * Make sure the memory ranges are not inverted and reject such ranges.
     * Move granule_tracking_get/gpt_info wrappers closer to the callers
       Drop "inline", let the compiler do its job
 Changes since v17:
     * Move wrappers that may not be used elsewhere, out of arm-rmi-cmds.h
 Changes since v16:
     * Check fine tracking and create L1 GPTs for hotplug-added memory.
     * Clarify the L1 GPT setup and move the explanatory comment.
     * Switch to using RMI_GPT_INFO command for checking the GPTs.
     * Deactivate the RMM and reclaim the memory if we can't proceed.
 Changes since v15:
     * Skip firmware-reserved NOMAP memory in rmi_init_metadata()
     * Handle negative error codes from wrappers.
 Changes since v14:
     * Move the implementation into drivers/firmware/arm_rmm.
 Changes since v13:
     * Moved out of KVM
---
 drivers/firmware/arm_rmm/rmi.c | 218 ++++++++++++++++++++++++++++++++-
 include/linux/arm-rmi-cmds.h   |   2 +
 2 files changed, 219 insertions(+), 1 deletion(-)

diff --git a/drivers/firmware/arm_rmm/rmi.c b/drivers/firmware/arm_rmm/rmi.c
index 0859f256e192b..1a8f3debd844a 100644
--- a/drivers/firmware/arm_rmm/rmi.c
+++ b/drivers/firmware/arm_rmm/rmi.c
@@ -5,6 +5,7 @@
 
 #include <linux/cpufeature.h>
 #include <linux/memblock.h>
+#include <linux/memory.h>
 #include <linux/arm-rmi-cmds.h>
 #include <linux/slab.h>
 
@@ -13,6 +14,7 @@
 
 /* RMM defines RmiFeatureRegister0 to RmiFeatureRegister5. */
 static unsigned long rmi_feat_reg_cache[5] __ro_after_init;
+static bool arm64_rmi_is_available;
 
 /**
  * rmi_granule_range_undelegate() - Undelegate a range of granules
@@ -817,6 +819,210 @@ static int rmi_configure(void)
 	return ret;
 }
 
+/**
+ * rmi_granule_tracking_get() - Get configuration of a Granule tracking region
+ * @start: Base PA of the tracking region
+ * @end: End of the PA region
+ * @out_category: Memory category
+ * @out_state: Tracking region state
+ * @out_top: Top of the memory region
+ *
+ * Return: RMI return code
+ */
+static int rmi_granule_tracking_get(unsigned long start,
+				    unsigned long end,
+				    unsigned long *out_category,
+				    unsigned long *out_state,
+				    unsigned long *out_top)
+{
+	struct arm_smccc_1_2_regs regs = {
+		SMC_RMI_GRANULE_TRACKING_GET, start, end,
+	};
+
+	rmi_smccc_invoke(&regs);
+
+	if (regs.a0 != RMI_SUCCESS)
+		return regs.a0;
+
+	if (out_category)
+		*out_category = regs.a1;
+	if (out_state)
+		*out_state = regs.a2;
+	if (out_top)
+		*out_top = regs.a3;
+
+	return RMI_SUCCESS;
+}
+
+/*
+ * Make sure the area is tracked by RMM at FINE granularity.
+ * We do not support changing the tracking yet.
+ */
+static int rmi_verify_memory_tracking(phys_addr_t start, phys_addr_t end)
+{
+	while (start < end) {
+		unsigned long ret, category, state, next;
+
+		ret = rmi_granule_tracking_get(start, end, &category, &state, &next);
+		if (ret != RMI_SUCCESS)
+			return -ENOMEM;
+
+		if (WARN_ON(next <= start))
+			return -ENXIO;
+
+		if (state != RMI_TRACKING_FINE ||
+		    category != RMI_MEM_CATEGORY_CONVENTIONAL) {
+			/* TODO: Set granule tracking in this case */
+			pr_err("Granule tracking for region isn't fine/conventional: %llx-%lx\n",
+			       start, next);
+			return -ENODEV;
+		}
+		start = next;
+	}
+
+	return 0;
+}
+
+/*
+ * rmi_gpt_info - Query the GPT info for the given PAR.
+ * @start: Base of the physical address region
+ * @end: Top of the physical address region
+ * @out_top: Top of the physical address region for which
+ *		the GPT @out_gpt_par_state is valid
+ * @out_gpt_par_state: State of the GPT covered by [start, out_top)
+ */
+static long rmi_gpt_info(unsigned long start, unsigned long end,
+			 unsigned long *out_top,
+			 unsigned long *out_gpt_par_state)
+{
+	struct arm_smccc_1_2_regs regs = {
+		SMC_RMI_GPT_INFO, start, end,
+	};
+
+	rmi_smccc_invoke(&regs);
+	if (regs.a0 != RMI_SUCCESS)
+		return regs.a0;
+
+	if (out_top)
+		*out_top = regs.a1;
+	if (out_gpt_par_state)
+		*out_gpt_par_state = regs.a2;
+
+	return RMI_SUCCESS;
+}
+
+/*
+ * We do not support creating L1 GPTs yet. So, make sure that
+ * all the regions are managed by the firmware.
+ */
+static int rmi_verify_gpt_firmware_managed(phys_addr_t start, phys_addr_t end)
+{
+	unsigned long l0gpt_sz;
+	unsigned long next, par_state;
+
+	l0gpt_sz = 1UL << (30 + FIELD_GET(RMI_FEATURE_REGISTER_1_L0GPTSZ,
+					  rmi_feat_reg(1)));
+	start = ALIGN_DOWN(start, l0gpt_sz);
+	end = ALIGN(end, l0gpt_sz);
+
+	while (start < end) {
+		long ret = rmi_gpt_info(start, end, &next, &par_state);
+
+		if (ret != RMI_SUCCESS)
+			return -ENOMEM;
+
+		if (WARN_ON(next <= start))
+			return -ENXIO;
+
+		if (par_state != RMI_GPT_PAR_PLAT) {
+			pr_err("GPT for the region is not managed by firmware %llx-%lx\n",
+				start, next);
+			return -ENOMEM;
+		}
+		start = next;
+	}
+
+	return 0;
+}
+
+static int rmi_prepare_memory(phys_addr_t start, phys_addr_t end)
+{
+	int ret;
+
+	if (start >= end)
+		return -EINVAL;
+
+	ret = rmi_verify_memory_tracking(start, end);
+	if (ret)
+		return ret;
+
+	return rmi_verify_gpt_firmware_managed(start, end);
+}
+
+static int rmi_init_metadata(void)
+{
+	phys_addr_t start, end;
+	struct memblock_region *r;
+
+	for_each_mem_region(r) {
+		int ret;
+
+		/* Firmware-reserved NOMAP regions are not usable system RAM */
+		if (memblock_is_nomap(r))
+			continue;
+
+		start = PAGE_ALIGN(r->base);
+		end = PAGE_ALIGN_DOWN(r->base + r->size);
+		/* Too small ? */
+		if (start >= end)
+			continue;
+
+		ret = rmi_prepare_memory(start, end);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+static int rmi_memory_notifier(struct notifier_block *nb,
+			       unsigned long action, void *data)
+{
+	struct memory_notify *arg = data;
+	phys_addr_t start, end;
+	int ret;
+
+	if (action != MEM_GOING_ONLINE)
+		return NOTIFY_DONE;
+
+	start = PFN_PHYS(arg->start_pfn);
+	end = PFN_PHYS(arg->start_pfn + arg->nr_pages);
+	ret = rmi_prepare_memory(start, end);
+
+	return notifier_from_errno(ret);
+}
+
+static struct notifier_block rmi_memory_nb = {
+	.notifier_call = rmi_memory_notifier,
+};
+
+bool is_rmi_available(void)
+{
+	return arm64_rmi_is_available;
+}
+EXPORT_SYMBOL_GPL(is_rmi_available);
+
+static int rmi_init_memory(void)
+{
+	int ret;
+
+	ret = rmi_init_metadata();
+	if (ret)
+		return ret;
+
+	return register_memory_notifier(&rmi_memory_nb);
+}
+
 static int __init arm64_init_rmi(void)
 {
 	int ret;
@@ -843,9 +1049,19 @@ static int __init arm64_init_rmi(void)
 	if (ret) {
 		pr_err("RMM activate failed (%d)\n", ret);
 		ret = ret < 0 ? ret : -ENXIO;
+		return ret;
 	}
 
-	return ret;
+	ret = rmi_init_memory();
+	if (ret) {
+		/* Deactivate the RMM */
+		WARN_ON(rmi_sro_memxfer_cmd(sro, GFP_KERNEL, SMC_RMI_RMM_DEACTIVATE));
+		return ret;
+	}
+
+	arm64_rmi_is_available = true;
+	pr_info("RMI configured\n");
+	return 0;
 }
 
 /*
diff --git a/include/linux/arm-rmi-cmds.h b/include/linux/arm-rmi-cmds.h
index b03974fd8168c..5b177bb176326 100644
--- a/include/linux/arm-rmi-cmds.h
+++ b/include/linux/arm-rmi-cmds.h
@@ -70,6 +70,8 @@ static inline int rmi_undelegate_page(phys_addr_t phys)
 	return rmi_undelegate_range(phys, PAGE_SIZE);
 }
 
+bool is_rmi_available(void);
+
 long rmi_sro_memxfer_execute(struct rmi_sro_state *sro, gfp_t gfp);
 void rmi_sro_free(struct rmi_sro_state *sro);
 long rmi_sro_execute(struct arm_smccc_1_2_regs *regs);
-- 
2.43.0

[PATCH v19 7/7] firmware: arm_rmm: Add wrappers for Realm related RMI commands

[Suzuki K Poulose]

From: Steven Price <steven.price@arm.com>

Introduce wrappers for the RMI functions needed for creating and
managing realm guests. This will be used by the KVM to manage the
Realms

Reviewed-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@oss.qualcomm.com>
Signed-off-by: Steven Price <steven.price@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
---
Changes since v18:
  * Convert the last man standing nesting if - Gavin
  * Pass out_top for RMI_ERROR_RTT for rmi_rtt_destroy()
Changes since v17:
  * Avoid nesting if conditions for output populating RMI calls
  * Clean up comments
  * Always use arm_smccc_1_2_invoke() for RMI calls.
Changes since v16:
  * Split into a separate patch and move away from arch/arm64 to
    include/linux/.
  * Also moved into the firmware_rmm series from the KVM CCA support.
    This is done in a hope to reduce the merge conflicts and make
    the KVM CCA upstreaming in independent parallel chunks
---
 include/linux/arm-rmi-cmds.h | 467 +++++++++++++++++++++++++++++++++++
 1 file changed, 467 insertions(+)

diff --git a/include/linux/arm-rmi-cmds.h b/include/linux/arm-rmi-cmds.h
index 5b177bb176326..e03dd8316695d 100644
--- a/include/linux/arm-rmi-cmds.h
+++ b/include/linux/arm-rmi-cmds.h
@@ -88,4 +88,471 @@ long rmi_sro_execute(struct arm_smccc_1_2_regs *regs);
 	__ret;								\
 })
 
+/**
+ * rmi_rtt_data_map_init() - Create a mapping at protected IPA, copying contents
+ *			     from a given non-secure source granule.
+ * @rd: PA of the RD
+ * @data: PA of the target granule mapped in the guest
+ * @ipa: IPA at which the granule @data will be mapped in the guest
+ * @src: PA of the source granule with contents
+ * @flags: RMI_MEASURE_CONTENT if the contents should be measured
+ *
+ * Create a mapping from Protected IPA space to conventional memory, copying
+ * contents from a Non-secure Granule provided by the caller.
+ *
+ * Return: 0 on success, positive RMI result code or negative Linux error code
+ */
+static inline long rmi_rtt_data_map_init(unsigned long rd, unsigned long data,
+					 unsigned long ipa, unsigned long src,
+					 unsigned long flags)
+{
+	struct arm_smccc_1_2_regs regs = {
+		SMC_RMI_RTT_DATA_MAP_INIT, rd, data, ipa, src, flags
+	};
+
+	return rmi_sro_execute(&regs);
+}
+
+/**
+ * rmi_rtt_data_map() - Create mappings in protected IPA range with unknown contents
+ * @rd: PA of the RD
+ * @base: Base of the target IPA range
+ * @top: Top of the target IPA range
+ * @flags: Flags
+ * @oaddr: Output address set descriptor
+ * @out_top: Top address of range which was processed.
+ *
+ * Return: 0 on success, positive RMI result code or negative Linux error code
+ */
+static inline long rmi_rtt_data_map(unsigned long rd,
+				    unsigned long base,
+				    unsigned long top,
+				    unsigned long flags,
+				    unsigned long oaddr,
+				    unsigned long *out_top)
+{
+	struct arm_smccc_1_2_regs regs = {
+		SMC_RMI_RTT_DATA_MAP, rd, base, top, flags, oaddr
+	};
+	long ret;
+
+	ret = rmi_sro_execute(&regs);
+
+	if (ret == RMI_SUCCESS && out_top)
+		*out_top = regs.a1;
+
+	return ret;
+}
+
+/**
+ * rmi_rtt_data_unmap() - Remove mappings to conventional memory at a protected
+ *			  IPA range
+ * @rd: PA of the RD
+ * @base: Base of the target IPA range
+ * @top: Top of the target IPA range
+ * @flags: Flags
+ * @oaddr: Output address set descriptor
+ * @out_top: Returns top IPA of range which has been unmapped
+ * @out_range: Output address range
+ * @out_count: Number of entries in output address list
+ *
+ * Removes mappings to convention memory with a target Protected IPA range.
+ *
+ * Return: 0 on success, positive RMI result code or negative Linux error code
+ */
+static inline long rmi_rtt_data_unmap(unsigned long rd,
+				      unsigned long base,
+				      unsigned long top,
+				      unsigned long flags,
+				      unsigned long oaddr,
+				      unsigned long *out_top,
+				      unsigned long *out_range,
+				      unsigned long *out_count)
+{
+	struct arm_smccc_1_2_regs regs = {
+		SMC_RMI_RTT_DATA_UNMAP, rd, base, top, flags, oaddr
+	};
+	long ret;
+
+	ret = rmi_sro_execute(&regs);
+
+	if (ret != RMI_SUCCESS)
+		return ret;
+
+	if (out_top)
+		*out_top = regs.a1;
+	if (out_range)
+		*out_range = regs.a2;
+	if (out_count)
+		*out_count = regs.a3;
+
+	return RMI_SUCCESS;
+}
+
+/**
+ * rmi_psci_complete() - Complete pending PSCI command
+ * @calling_rec: PA of the calling REC
+ * @status: Status of the PSCI request
+ *
+ * Completes a pending PSCI command.
+ *
+ * Return: RMI return code
+ */
+static inline long rmi_psci_complete(unsigned long calling_rec,
+				     unsigned long status)
+{
+	struct arm_smccc_1_2_regs regs = {
+		SMC_RMI_PSCI_COMPLETE, calling_rec, status,
+	};
+
+	rmi_smccc_invoke(&regs);
+	return regs.a0;
+}
+
+/**
+ * rmi_realm_activate() - Activate a realm
+ * @rd: PA of the RD
+ *
+ * Mark a realm as Active, signalling that creation is completed, allowing
+ * execution of the realm.
+ *
+ * Return: RMI return code
+ */
+static inline long rmi_realm_activate(unsigned long rd)
+{
+	struct arm_smccc_1_2_regs regs = {
+		SMC_RMI_REALM_ACTIVATE, rd,
+	};
+
+	rmi_smccc_invoke(&regs);
+	return regs.a0;
+}
+
+/**
+ * rmi_realm_create() - Create a realm
+ * @rd: PA of the RD
+ * @params: PA of realm parameters
+ * @sro: Preallocated SRO context
+ *
+ * Create a new realm using the given parameters.
+ *
+ * Return: 0 on success, positive RMI result code or negative Linux error code
+ */
+static inline long rmi_realm_create(unsigned long rd, unsigned long params,
+				    struct rmi_sro_state *sro)
+{
+	return rmi_sro_memxfer_cmd(sro, GFP_KERNEL,
+				   SMC_RMI_REALM_CREATE, rd, params);
+}
+
+/**
+ * rmi_realm_terminate() - Terminate a realm
+ * @rd: PA of the RD
+ * @sro: Preallocated SRO context
+ *
+ * Terminates a realm, moving it into a ZOMBIE state
+ *
+ * Return: 0 on success, positive RMI result code or negative Linux error code
+ */
+static inline long rmi_realm_terminate(unsigned long rd,
+				       struct rmi_sro_state *sro)
+{
+	return rmi_sro_memxfer_cmd(sro, GFP_KERNEL,
+				   SMC_RMI_REALM_TERMINATE, rd);
+}
+
+/**
+ * rmi_realm_destroy() - Destroy a realm
+ * @rd: PA of the RD
+ * @sro: Preallocated SRO context
+ *
+ * Destroys a realm, all objects belonging to the realm must be destroyed first.
+ *
+ * Return: 0 on success, positive RMI result code or negative Linux error code
+ */
+static inline long rmi_realm_destroy(unsigned long rd,
+				     struct rmi_sro_state *sro)
+{
+	return rmi_sro_memxfer_cmd(sro, GFP_KERNEL,
+				   SMC_RMI_REALM_DESTROY, rd);
+}
+
+/**
+ * rmi_rec_create() - Create a REC
+ * @rd: PA of the RD
+ * @rec: PA of the target REC
+ * @params: PA of REC parameters
+ * @sro: Allocated SRO context to be used
+ *
+ * Create a REC using the parameters specified in the struct rec_params pointed
+ * to by @params.
+ *
+ * Return: 0 on success, positive RMI result code or negative Linux error code
+ */
+static inline long rmi_rec_create(unsigned long rd,
+				  unsigned long rec,
+				  unsigned long params,
+				  struct rmi_sro_state *sro)
+{
+	long ret;
+
+	sro->addr_count = 0;
+	sro->regs = (struct arm_smccc_1_2_regs) {
+		SMC_RMI_REC_CREATE, rd, rec, params
+	};
+	ret = rmi_sro_memxfer_execute(sro, GFP_KERNEL);
+	rmi_sro_free(sro);
+
+	return ret;
+}
+
+/**
+ * rmi_rec_destroy() - Destroy a REC
+ * @rec: PA of the target REC
+ * @sro: Allocated SRO context to be used
+ *
+ * Destroys a REC. The REC must not be running.
+ *
+ * Return: 0 on success, positive RMI result code or negative Linux error code
+ */
+static inline long rmi_rec_destroy(unsigned long rec,
+				   struct rmi_sro_state *sro)
+{
+	return rmi_sro_memxfer_cmd(sro, GFP_KERNEL, SMC_RMI_REC_DESTROY, rec);
+}
+
+/**
+ * rmi_rec_enter() - Enter a REC
+ * @rec: PA of the target REC
+ * @run_ptr: PA of RecRun structure
+ *
+ * Starts (or continues) execution within a REC.
+ *
+ * Return: RMI return code
+ */
+static inline long rmi_rec_enter(unsigned long rec, unsigned long run_ptr)
+{
+	struct arm_smccc_1_2_regs regs = {
+		SMC_RMI_REC_ENTER, rec, run_ptr,
+	};
+
+	rmi_smccc_invoke(&regs);
+	return regs.a0;
+}
+
+/**
+ * rmi_rtt_create() - Creates an RTT
+ * @rd: PA of the RD
+ * @rtt: PA of the target RTT
+ * @ipa: Base of the IPA range described by the RTT
+ * @level: Depth of the RTT within the tree
+ *
+ * Creates an RTT (Realm Translation Table) at the specified level for the
+ * translation of the specified address within the realm.
+ *
+ * Return: 0 on success, positive RMI result code or negative Linux error code
+ */
+static inline long rmi_rtt_create(unsigned long rd, unsigned long rtt,
+				  unsigned long ipa, long level)
+{
+	struct arm_smccc_1_2_regs regs = {
+		SMC_RMI_RTT_CREATE, rd, rtt, ipa, level
+	};
+
+	return rmi_sro_execute(&regs);
+}
+
+/**
+ * rmi_rtt_destroy() - Destroy an RTT
+ * @rd: PA of the RD
+ * @ipa: Base of the IPA range described by the RTT
+ * @level: RTT level
+ * @out_rtt: Pointer to write the PA of the RTT which was destroyed
+ * @out_top: Pointer to write the top IPA of non-live RTT entries, from entry
+ * at which the RTT walk terminated.
+ *
+ * Destroys an RTT. The RTT must be non-live, i.e. none of the entries in the
+ * table are in ASSIGNED or TABLE state.
+ *
+ * Return: 0 on success, positive RMI result code or negative Linux error code.
+ */
+static inline long rmi_rtt_destroy(unsigned long rd,
+				   unsigned long ipa,
+				   long level,
+				   unsigned long *out_rtt,
+				   unsigned long *out_top)
+{
+	struct arm_smccc_1_2_regs regs = {
+		SMC_RMI_RTT_DESTROY, rd, ipa, level
+	};
+	long ret = rmi_sro_execute(&regs);
+
+	switch (RMI_RESULT_STATUS(ret)) {
+	case RMI_SUCCESS:
+		if (out_rtt)
+			*out_rtt = regs.a1;
+		fallthrough;
+	case RMI_ERROR_RTT:
+		if (out_top)
+			*out_top = regs.a2;
+		break;
+	default:
+		break;
+	}
+
+	return ret;
+}
+
+/**
+ * rmi_rtt_fold() - Fold an RTT
+ * @rd: PA of the RD
+ * @ipa: Base of the IPA range described by the RTT
+ * @level: Depth of the RTT within the tree
+ * @out_rtt: Pointer to write the PA of the RTT which was destroyed
+ *
+ * Folds an RTT. If all entries with the RTT are 'homogeneous' the RTT can be
+ * folded into the parent and the RTT destroyed.
+ *
+ * Return: 0 on success, positive RMI result code or negative Linux error code
+ */
+static inline long rmi_rtt_fold(unsigned long rd, unsigned long ipa,
+				long level, unsigned long *out_rtt)
+{
+	struct arm_smccc_1_2_regs regs = {
+		SMC_RMI_RTT_FOLD, rd, ipa, level
+	};
+	long ret = rmi_sro_execute(&regs);
+
+	if (ret == RMI_SUCCESS && out_rtt)
+		*out_rtt = regs.a1;
+
+	return ret;
+}
+
+/**
+ * rmi_rtt_init_ripas() - Set RIPAS for new realm
+ * @rd: PA of the RD
+ * @base: Base of target IPA region
+ * @top: Top of target IPA region
+ * @out_top: Top IPA of range whose RIPAS was modified
+ *
+ * Sets the RIPAS of a target IPA range to RAM, for a realm in the NEW state.
+ *
+ * Return: 0 on success, positive RMI result code or negative Linux error code
+ */
+static inline long rmi_rtt_init_ripas(unsigned long rd, unsigned long base,
+				      unsigned long top, unsigned long *out_top)
+{
+	struct arm_smccc_1_2_regs regs = {
+		SMC_RMI_RTT_INIT_RIPAS, rd, base, top
+	};
+	long ret = rmi_sro_execute(&regs);
+
+	if (ret == RMI_SUCCESS && out_top)
+		*out_top = regs.a1;
+
+	return ret;
+}
+
+/**
+ * rmi_rtt_unprot_map() - Map unprotected granules into a realm
+ * @rd: PA of the RD
+ * @base: Base IPA of the mapping
+ * @top: Top of the target IPA range
+ * @flags: Flags
+ * @oaddr: Output address set descriptor
+ * @out_top: Top IPA of range which has been mapped
+ *
+ * Create mappings to memory within a target unprotected IPA range.
+ *
+ * Return: 0 on success, positive RMI result code or negative Linux error code
+ */
+static inline long rmi_rtt_unprot_map(unsigned long rd,
+				      unsigned long base,
+				      unsigned long top,
+				      unsigned long flags,
+				      unsigned long oaddr,
+				      unsigned long *out_top)
+{
+	struct arm_smccc_1_2_regs regs = {
+		SMC_RMI_RTT_UNPROT_MAP, rd, base, top, flags, oaddr
+	};
+	long ret = rmi_sro_execute(&regs);
+
+	if (ret == RMI_SUCCESS && out_top)
+		*out_top = regs.a1;
+
+	return ret;
+}
+
+/**
+ * rmi_rtt_set_ripas() - Set RIPAS for an running realm
+ * @rd: PA of the RD
+ * @rec: PA of the REC making the request
+ * @base: Base of target IPA region
+ * @top: Top of target IPA region
+ * @out_top: Pointer to write top IPA of range whose RIPAS was modified
+ *
+ * Completes a request made by the realm to change the RIPAS of a target IPA
+ * range.
+ *
+ * Return: 0 on success, positive RMI result code or negative Linux error code
+ */
+static inline long rmi_rtt_set_ripas(unsigned long rd, unsigned long rec,
+				     unsigned long base, unsigned long top,
+				     unsigned long *out_top)
+{
+	struct arm_smccc_1_2_regs regs = {
+		SMC_RMI_RTT_SET_RIPAS, rd, rec, base, top
+	};
+	long ret = rmi_sro_execute(&regs);
+
+	if (ret == RMI_SUCCESS && out_top)
+		*out_top = regs.a1;
+
+	return ret;
+}
+
+/**
+ * rmi_rtt_unprot_unmap() - Remove mappings within an unprotected IPA range
+ * @rd: PA of the RD
+ * @base: Base IPA of the mapping
+ * @top: Top of the target IPA range
+ * @flags: Flags
+ * @oaddr: Output address set descriptor
+ * @out_top: Top IPA which has been unmapped
+ * @out_range: Output address range
+ * @out_count: Number of entries in output address list
+ *
+ * Removes mappings to memory within a target unprotected IPA range.
+ *
+ * Return: 0 on success, positive RMI result code or negative Linux error code
+ */
+static inline long rmi_rtt_unprot_unmap(unsigned long rd,
+					unsigned long base,
+					unsigned long top,
+					unsigned long flags,
+					unsigned long oaddr,
+					unsigned long *out_top,
+					unsigned long *out_range,
+					unsigned long *out_count)
+{
+	struct arm_smccc_1_2_regs regs = {
+		SMC_RMI_RTT_UNPROT_UNMAP, rd, base, top, flags, oaddr
+	};
+	long ret = rmi_sro_execute(&regs);
+
+	if (ret != RMI_SUCCESS)
+		return ret;
+
+	if (out_top)
+		*out_top = regs.a1;
+	if (out_range)
+		*out_range = regs.a2;
+	if (out_count)
+		*out_count = regs.a3;
+
+	return RMI_SUCCESS;
+}
+
 #endif
-- 
2.43.0

Re: [PATCH v19 1/7] firmware: arm_rmm: Add SMC definitions for calling the RMM

[Jonathan Cameron]

On Thu, 24 Sep 2026 14:51:55 +0100
Suzuki K Poulose <suzuki.poulose@arm.com> wrote:

> From: Steven Price <steven.price@arm.com>
> 
> The RMM (Realm Management Monitor) provides functionality that can be
> accessed by SMC calls from the host.
> 
> The SMC definitions are based on DEN0137[1] version 2.0-bet3
> 
> [1] https://developer.arm.com/documentation/den0137/2-0bet3/
> 
> Reviewed-by: Gavin Shan <gshan@redhat.com>
> Signed-off-by: Steven Price <steven.price@arm.com>
> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>

Hi Suzuki,

One small thing I didn't really care about but where I thought you
said you were going to tweak things.

Either way
Reviewed-by: Jonathan Cameron <jonathan.cameron@oss.qualcomm.com>

> +struct rec_exit {
> +	union { /* 0x000 */
> +		u8 exit_reason;
> +		u8 padding0[0x100];
> +	};
> +	union { /* 0x100 */
> +		struct {
> +			u64 esr;
> +			u64 far;
> +			u64 hpfar;
> +			u64 rtt_tree;
> +		};
> +		u8 padding1[0x100];
> +	};
> +	union { /* 0x200 */
> +		u64 gprs[REC_RUN_GPRS];
> +		u8 padding2[0x100];
> +	};
> +	union { /* 0x300 */
> +		u8 padding3[0x100];

I thought plan was to fold into the padding above?

https://lore.kernel.org/all/d7ccaf22-5bde-4344-8bf0-a5a17dcac0f3@arm.com/

> +	};
> +	union { /* 0x400 */
> +		struct {
> +			u64 cntp_ctl;
> +			u64 cntp_cval;
> +			u64 cntv_ctl;
> +			u64 cntv_cval;
> +		};
> +		u8 padding4[0x100];
> +	};

Re: [PATCH v19 2/7] firmware: arm_rmm: Check for RMI support at init

[Jonathan Cameron]

On Thu, 24 Sep 2026 14:51:56 +0100
Suzuki K Poulose <suzuki.poulose@arm.com> wrote:

> From: Steven Price <steven.price@arm.com>
> 
> Query the RMI version number and check if it is a compatible version.
> The first two feature registers are read and exposed for future code to
> use.
> 
> We only support this for Little Endian kernels, the Big Endian kernel
> support is anyway marked BROKEN and is being removed.
> 
> Signed-off-by: Steven Price <steven.price@arm.com>
> Co-developed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@oss.qualcomm.com>

Re: [PATCH v19 3/7] firmware: arm_rmm: Configure the RMM with the host's page size

[Jonathan Cameron]

On Thu, 24 Sep 2026 14:51:57 +0100
Suzuki K Poulose <suzuki.poulose@arm.com> wrote:

> RMM v2.0 brings the ability to set the RMM's granule size. Check the
> feature registers and configure the RMM so that it matches the host's
> page size. This means that operations can be done with a granularity
> equal to PAGE_SIZE.
> 
> Signed-off-by: Steven Price <steven.price@arm.com>
> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Hi Suzuki,

Some trivial stuff inline.  Assuming that is addressed.

Reviewed-by: Jonathan Cameron <jonathan.cameron@oss.qualcomm.com>

> ---
>  drivers/firmware/arm_rmm/rmi.c | 70 ++++++++++++++++++++++++++++++++++
>  1 file changed, 70 insertions(+)
> 
> diff --git a/drivers/firmware/arm_rmm/rmi.c b/drivers/firmware/arm_rmm/rmi.c
> index 3baba931f92e4..c9ea964fd9081 100644
> --- a/drivers/firmware/arm_rmm/rmi.c
> +++ b/drivers/firmware/arm_rmm/rmi.c

> +
> +static int rmi_configure(void)
> +{
> +	unsigned long granule_feature;
> +	unsigned long granule_size;
> +	int ret = 0;

Value not used.  Fine if it is future churn reduction, but I didn't spot
where if so. I'm guessing left over from refactoring

> +
> +	switch (PAGE_SIZE) {
> +	case SZ_4K:
> +		granule_size = RMI_GRANULE_SIZE_4KB;
> +		granule_feature = RMI_FEATURE_REGISTER_1_RMI_GRAN_SZ_4KB;
> +		break;
> +	case SZ_16K:
> +		granule_size = RMI_GRANULE_SIZE_16KB;
> +		granule_feature = RMI_FEATURE_REGISTER_1_RMI_GRAN_SZ_16KB;
> +		break;
> +	case SZ_64K:
> +		granule_size = RMI_GRANULE_SIZE_64KB;
> +		granule_feature = RMI_FEATURE_REGISTER_1_RMI_GRAN_SZ_64KB;
> +		break;
> +	default:
> +		BUILD_BUG();
> +	}
> +
> +	if (!(rmi_feat_reg(1) & granule_feature)) {
> +		pr_err("RMM does not support %luKB granules\n",
> +		       PAGE_SIZE >> 10);
> +		return -ENXIO;
> +	}
> +
> +	struct rmm_config *config __free(free_page) =
> +		(struct rmm_config *)get_zeroed_page(GFP_KERNEL);
> +
> +	if (!config) {
> +		pr_err("Unable to allocate memory for RMM config\n");
> +		return -ENOMEM;
> +	}
> +
> +	config->rmi_granule_size = granule_size;
> +
> +	/*
> +	 * For now we set the tracking_region_size to 0 which is the only option
> +	 * for 4KB PAGE_SIZE (1GB for 4KB PAGE_SIZE, 32MB/512MB for 16KB/64KB).
> +	 * TODO: Support other tracking sizes via Kconfig option for other
> +	 * PAGE_SIZES
> +	 */
> +	config->tracking_region_size = 0;
> +
> +	ret = rmi_rmm_config_set(virt_to_phys(config));
> +	if (ret) {
> +		pr_err("RMM config set failed (%d)\n", ret);
> +		ret = -EINVAL;

		return -EINVAL;

> +	}
> +
> +	return ret;
	return 0;

So obvious this is the good path without anyone having to think about it!

I did quick check on whether this was to reduce churn due to later changes
but couldn't immediately spot anything


> +}

Re: [PATCH v19 1/7] firmware: arm_rmm: Add SMC definitions for calling the RMM

[Ackerley Tng]

Suzuki K Poulose <suzuki.poulose@arm.com> writes:

>
> [...snip...]
>
> +
> +/*
> + * Note many of these fields are smaller than u64 but all fields have u64
> + * alignment, so use u64 to ensure correct alignment.
> + */
> +struct rmm_config {
> +	union { /* 0x0 */
> +		struct {
> +			u64 tracking_region_size;
> +			u64 rmi_granule_size;
> +		};
> +		u8 sizer[SZ_4K];
> +	};
> +};
> +
> +static_assert(sizeof(struct rmm_config) == SZ_4K);
> +
> +#define RMI_REALM_PARAM_FLAG_MEC_POLICY_MASK	GENMASK(8, 7)
> +#define RMI_REALM_PARAM_FLAG_LFA_POLICY_MASK	GENMASK(6, 5)
> +#define RMI_REALM_PARAM_FLAG_DA			BIT(3)
> +#define RMI_REALM_PARAM_FLAG_PMU		BIT(2)
> +#define RMI_REALM_PARAM_FLAG_SVE		BIT(1)
> +
> +#define RMI_HASH_SHA_256			0
> +#define RMI_HASH_SHA_512			1
> +#define RMI_HASH_SHA_384			2
> +
> +struct realm_params {
> +	union { /* 0x0 */
> +		struct {
> +			u64 flags0;
> +			u64 s2sz;
> +			u64 sve_vl;
> +			u64 num_bps;
> +			u64 num_wps;
> +			u64 pmu_num_ctrs;
> +			u64 hash_algo;
> +			u64 num_aux_planes;
> +		};
> +		u8 padding0[0x400];

The union + sizer concept is cool. Technically this one isn't a padding,
it's also a sizer? (same for the other structs below.

> +	};
> +	union { /* 0x400 */
> +		struct {
> +			u8 rpv[64];
> +			u64 ats_plane;
> +		};
> +		u8 padding1[0x400];
> +	};
> +	union { /* 0x800 */
> +		struct {
> +			u64 padding2;
> +			u64 rtt_base;
> +			s64 rtt_level_start;
> +			u64 rtt_num_start;
> +			u64 flags1;
> +			u64 max_num_vdevs;
> +		};
> +		u8 padding3[0x700];
> +	};
> +	union { /* 0xf00 */
> +		struct {
> +			u8 padding4[0x80];
> +			u64 aux_rtt_base[3];
> +		};
> +		u8 padding5[0x100];
> +	};
> +};
> +
> +static_assert(sizeof(struct realm_params) == SZ_4K);
> +

Does declaring this struct as packed matter? I guess the static_assert()
has the same effect.

>
> [...snip...]
>

Re: [PATCH v19 4/7] firmware: arm_rmm: Add support for SRO

[Jonathan Cameron]

On Thu, 24 Sep 2026 14:51:58 +0100
Suzuki K Poulose <suzuki.poulose@arm.com> wrote:

> From: Steven Price <steven.price@arm.com>
> 
> RMM v2.0 introduces the concept of "Stateful RMI Operations" (SRO). This
> means that an SMC can return with an operation still in progress. The
> host is expected to continue the operation until it reaches a conclusion
> (either success or failure). During this process the RMM can request
> additional memory ('donate') or hand memory back to the host
> ('reclaim'). The host can request an in progress operation is cancelled,
> but still continue the operation until it has completed (otherwise the
> incomplete operation may cause future RMM operations to fail).
> 
> The SRO is tracked using a struct rmi_sro_state object which keeps track
> of any memory which has been allocated but not yet consumed by the RMM
> or reclaimed from the RMM. This allows the memory to be reused in a
> future request within the same operation. It will also permit an
> operation to be done in a context where memory allocation may be
> difficult (e.g. atomic context) with the option to abort the operation
> and retry the memory allocation outside of the atomic context. The
> memory stored in the struct rmi_sro_state object can then be reused on
> the subsequent attempt.
> 
> Wrappers for SRO RMI commands are also provided here because they depend
> on the rmi_sro_execute() implementation added by this patch.
> Delegate/undelegate handles are also added here because they now use the
> SRO/stateful command infrastructure and are also used for the memory
> DONATE/RECLAIM flows.
> 
> Signed-off-by: Steven Price <steven.price@arm.com>
> Co-developed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>

Nice.  Everything I spotted this time around is pretty trivial.
So assuming you'll clean up and bits that make sense to you for v20

Reviewed-by: Jonathan Cameron <jonathan.cameron@oss.qualcomm.com>


> ---
>  drivers/firmware/arm_rmm/rmi.c | 666 +++++++++++++++++++++++++++++++++
>  include/linux/arm-rmi-cmds.h   |  41 ++
>  2 files changed, 707 insertions(+)
> 
> diff --git a/drivers/firmware/arm_rmm/rmi.c b/drivers/firmware/arm_rmm/rmi.c
> index c9ea964fd9081..035f21d3f26b6 100644
> --- a/drivers/firmware/arm_rmm/rmi.c
> +++ b/drivers/firmware/arm_rmm/rmi.c

> +
> +int rmi_undelegate_range(phys_addr_t phys,
> +			 unsigned long size)
> +{
> +	long ret = 0;
> +	unsigned long top = phys + size;
> +	unsigned long out_top;
> +
> +	while (phys < top) {
> +		ret = rmi_granule_range_undelegate(phys, top, &out_top);
> +
> +		if (ret == RMI_SUCCESS) {
> +			/* Buggy RMM ? Let the caller leak the pages */
> +			if (WARN_ON(out_top <= phys))
> +				return -ENXIO;
> +			phys = out_top;
> +		} else {

Similar to below, why not deal with error case first and reduce indent of
the good path.

> +			break;
> +		}
> +	}
> +
> +	return ret;
> +}
> +EXPORT_SYMBOL_GPL(rmi_undelegate_range);

> +/*
> + * rmi_delegate_range: Delegate a physically contiguous range.
> + * We iterate over the range until we hit an error. So we may
> + * return an error, but with a partially delegated range. The
> + * caller must always look at the @out_phys to figure out, how
> + * much progress was made.
> + *
> + * @phys:	Base of the physical address range
> + * @size:	Size of the physical address range
> + * @out_phys:	Top of the range that was completed. This is always
> + *		valid, irrespective of the result.
> + *
> + * Returns RMI_SUCCESS on successful completion. Otherwise, returns
> + * the Linux error number or the RMI status code as described
> + * by the RMM spec for RMI_GRANULE_DELEGATE_RANGE or RMI_BLOCKED.
> + */
> +int rmi_delegate_range(phys_addr_t phys,
> +		       unsigned long size,
> +		       phys_addr_t *out_phys)
> +{
> +	long ret = 0;
> +	unsigned long top = phys + size;
> +	unsigned long out_top;
> +
> +	while (phys < top) {
> +		ret = rmi_granule_range_delegate(phys, top, &out_top);
> +
> +		if (ret == RMI_SUCCESS) {

My instinct here would be to flip this and have the error out of line given
it breaks anyway and that gives you smaller indent for that ocmment block.

		if (ret != RMI_SUCCESS)
			break;

		/*
		 * Buggy RMM ? Let the caller handle the failure. We can't know
		 * how far the RMM delegated in this iteration, so we return 
 		 * the best known good limit. RMM can deal with granules 
		 * already in "undelegated" in a given range. So, it is fine
		 * for the caller to try the range we return.
		 */
		if (WARN_ON...

> +			/*
> +			 * Buggy RMM ? Let the caller handle the failure.
> +			 * We can't know how far the RMM delegated in this
> +			 * iteration, so we return the best known good limit.
> +			 * RMM can deal with granules already in "undelegated"
> +			 * in a given range. So, it is fine for the caller to
> +			 * try the range we return.
> +			 */
> +			if (WARN_ON(out_top <= phys)) {
> +				ret = -ENXIO;
> +				break;
> +			}
> +			phys = out_top;
> +		} else {
> +			break;
> +		}
> +	}
> +
> +	if (out_phys)
> +		*out_phys = phys;
> +
> +	return ret;
> +}
> +EXPORT_SYMBOL_GPL(rmi_delegate_range);

...

> +
> +static int rmi_sro_donate_noncontig(struct rmi_sro_state *sro,
> +				    unsigned long sro_handle,
> +				    unsigned long donatereq,
> +				    struct arm_smccc_1_2_regs *out_regs,
> +				    gfp_t gfp)
> +{

...

> +
> +	/* Gather the suitable entries to the end of the list */
> +	i = 0;
> +	while (i <  addr_list_start && found < count) {
> +		unsigned long entry = sro->addr_list[i];
> +
> +		if (RMI_ADDR_RANGE_BLOCK_SIZE(entry) == block_size_fld &&
> +		    RMI_ADDR_RANGE_COUNT(entry) == 1 &&
> +		    RMI_ADDR_RANGE_STATE(entry) == state) {
> +			addr_list_start--;
> +			swap(sro->addr_list[addr_list_start],
> +			     sro->addr_list[i]);
> +			found++;
> +			/* Continue from the swapped in entry */
> +			continue;
> +		}
> +		/* skip past the entry */

Bit random on comment capitalization.  Have a quick final look through.
For instance I think this one is Skip to match Continue above.

> +		i++;
> +	}

...


> +
> +static int rmi_sro_reclaim(struct rmi_sro_state *sro,
> +			   unsigned long sro_handle,
> +			   struct arm_smccc_1_2_regs *out_regs)
> +{
> +	unsigned long capacity;
> +
> +	/*
> +	 * We don't do a partial free of the entries. So for
> +	 * now free the entire address list as we prepare
> +	 * to reclaim more from the RMM.

Rewrap to use all that nice space up to 80 chars!  I guess a refactoring
side effect.

> +	 */
> +	if (rmi_sro_ensure_capacity(sro, 1))
> +		rmi_sro_free(sro);
> +
> +	capacity = RMI_MAX_ADDR_LIST - sro->addr_count;
> +
> +	rmi_op_mem_reclaim(sro_handle,
> +			   virt_to_phys(&sro->addr_list[sro->addr_count]),
> +			   capacity, out_regs);
> +
> +	/*
> +	 * RMI_OP_MEM_RECLAIM always return RMI_INCOMPLETE, except when the
> +	 * input parameters were invalid.
> +	 */
> +	if (WARN_ON_ONCE(RMI_RESULT_STATUS(out_regs->a0) != RMI_INCOMPLETE))
> +		return -EINVAL;
> +	if (WARN_ON_ONCE(out_regs->a1 > capacity))
> +		out_regs->a1 = capacity;
> +
> +	sro->addr_count += out_regs->a1;
> +
> +	return 0;
> +}

> +
> +long rmi_sro_memxfer_execute(struct rmi_sro_state *sro, gfp_t gfp)
> +{
> +	struct arm_smccc_1_2_regs *regs = &sro->regs;
> +	bool cancelled = false;
> +	unsigned long sro_handle;
> +
> +	rmi_smccc_invoke(regs);
> +
> +	sro_handle = regs->a1;
> +	while (RMI_RESULT_STATUS(regs->a0) == RMI_INCOMPLETE) {
> +		bool can_cancel = RMI_RESULT_CAN_CANCEL(regs->a0) == RMI_OP_CAN_CANCEL;

For a flag that is "can" or "cannot", do we need the RMI_OP_CAN_CANCEL (1) / RMI_OP_CANNOT_CANCEL (0)
defines?  Doesn't feel like we'll ever get RMI_OP_UNKNOWN_IF_IT_CAN_CANCEL and I can't think
of any other more reasonable options that would justify needing the explicit field value
match.

To me

		bool can_cancel = RMI_RESULT_CAN_CANCEL(regs->a0);

is obvious enough.  I don't care that much though so up to you.


> +		int ret = 0;
> +
> +		switch (RMI_RESULT_MEMREQ(regs->a0)) {
> +		case RMI_OP_MEM_REQ_NONE:
> +			rmi_op_continue(sro_handle, RMI_CONTINUE_KEEP_GOING,
> +					regs);
> +			break;
> +		case RMI_OP_MEM_REQ_DONATE:
> +			ret = rmi_sro_donate(sro, sro_handle, regs->a2, regs,
> +					     gfp);
> +			break;
> +		case RMI_OP_MEM_REQ_RECLAIM:
> +			ret = rmi_sro_reclaim(sro, sro_handle, regs);
> +			break;
> +		default:
> +			WARN_ON_ONCE(1);
> +			ret = -ENXIO;
> +			break;
> +		}
> +
> +		if (ret) {
> +			/*
> +			 * All memory donating SROs must be cancellable. So a
> +			 * failure in memory allocation shouldn't be an issue.
> +			 * However, if we encounter a random failure (e.g.,
> +			 * buggy RMM), don't loop forever, just give up.
> +			 */
> +			if (WARN_ON_ONCE(!can_cancel))
> +				return ret;
> +			/*
> +			 * If we have already cancelled, and came back here due
> +			 * to an error in MEMREQ, then there is no point
> +			 * in going in loops.
> +			 */
> +			if (WARN_ON_ONCE(cancelled))
> +				break;
> +			rmi_op_cancel(sro_handle, regs);
> +			cancelled = true;
> +
> +			if (WARN_ON_ONCE(RMI_RESULT_STATUS(regs->a0) != RMI_INCOMPLETE))
> +				return ret;
> +		}
> +	}
> +
> +	if (cancelled)
> +		return -ECANCELED;
> +
> +	return regs->a0;
> +}
> +EXPORT_SYMBOL_GPL(rmi_sro_memxfer_execute);
> +
> +/*
> + * rmi_sro_execute: Execute an RMI command that is Stateful but not memory
> + * tranfserring. Takes regs, filled with the FIDs and the arguments in place.

Spell check. Transferring.  Also why does Stateful get a capital letter and
Memory Transferring does not.  They seem to both be properties of the comman
so I'd expect some consistency.

> + *
> + * Returns :
> + *  -ECANCELLED - If the operation had to be aborted and SRO was cancellable.
> + *  Otherwise, returns the result of the RMI command.
> + */
> +long rmi_sro_execute(struct arm_smccc_1_2_regs *regs)
> +{
> +	bool cancelled = false;
> +	unsigned long sro_handle = regs->a1;
> +
> +	rmi_smccc_invoke(regs);
> +
> +	sro_handle = regs->a1;
> +	while (RMI_RESULT_STATUS(regs->a0) == RMI_INCOMPLETE) {
> +		bool can_cancel = RMI_RESULT_CAN_CANCEL(regs->a0) == RMI_OP_CAN_CANCEL;
> +
> +		switch (RMI_RESULT_MEMREQ(regs->a0)) {
> +		case RMI_OP_MEM_REQ_NONE:
> +			rmi_op_continue(sro_handle, RMI_CONTINUE_KEEP_GOING,
> +					regs);
> +			break;
> +		default:
> +			WARN_ON_ONCE(1);
> +			if (!can_cancel)
> +				return regs->a0;
> +			/*
> +			 * We can't get here normally, but handle this anyway
> +			 * for a buggy RMM implementation.
> +			 */
> +			if (cancelled)
> +				return -ECANCELED;
> +			rmi_op_cancel(sro_handle, regs);
> +			cancelled = true;
> +		}
> +	}
> +
> +	if (cancelled)
> +		return -ECANCELED;
> +
> +	return regs->a0;
> +}
> +EXPORT_SYMBOL_GPL(rmi_sro_execute);