From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 009EA245AF8; Thu, 13 Feb 2025 22:22:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739485369; cv=none; b=YK0MgHmQ5mLAyejtV4KxKMWjVKTbFtBWAUk4wqmwTZuoZBzr7X1WW8Yk5+a7Zdez0yWNG7S/32CaSJU5v3bR2cWmFdhggR3F9yZIJRVtbLIEsla+l0XR1ApuEo7UlxcKr/l5iqBN++83yX/Or0PD7YtUvd4xeRjqE/Q/70cNK6o= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739485369; c=relaxed/simple; bh=ytUq0rzfHMChpiXV7qnsvrI47BzMXjO3CDqJrE9tpdg=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=Q5m1BJa2RYcl50Ui7PetbJYojL/pbfH9DToLHnGi4UBxvhzUv/QcA6bY4aoTfAKsU+OKJ4t3nCBNkfMomvTMbFKTNHUtroeHq8DpqtKCVRjbk9SxbvBnj8imvhPE7MKzsBWCcR0l36sqBm8RIg7HrR0fwOUnLtiVr4zp2zVdiNQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id DA9DB113E; Thu, 13 Feb 2025 14:23:05 -0800 (PST) Received: from [10.122.17.146] (unknown [10.122.17.146]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 045C93F5A1; Thu, 13 Feb 2025 14:22:44 -0800 (PST) Message-ID: <5f913165-f33e-4d14-8cc3-2e16507aab25@arm.com> Date: Thu, 13 Feb 2025 16:22:44 -0600 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 1/5] tpm_crb: implement driver compliant to CRB over FF-A To: Jarkko Sakkinen Cc: linux-integrity@vger.kernel.org, peterhuewe@gmx.de, jgg@ziepe.ca, sudeep.holla@arm.com, rafael@kernel.org, lenb@kernel.org, linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org References: <20250212220548.400447-1-stuart.yoder@arm.com> <20250212220548.400447-2-stuart.yoder@arm.com> Content-Language: en-US From: Stuart Yoder In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 2/13/25 4:14 PM, Jarkko Sakkinen wrote: > On Wed, Feb 12, 2025 at 04:05:44PM -0600, Stuart Yoder wrote: >> The Arm specification TPM Service CRB over FF-A specification >> defines the FF-A messages to interact with a CRB-based TPM >> implemented as an FF-A secure partition. >> >> Spec URL: >> https://developer.arm.com/documentation/den0138/latest/ >> >> This driver is probed when a TPM Secure Partition is >> discovered by the FF-A subsystem. It exposes APIs >> used by the TPM CRB driver to send notifications to >> the TPM. >> >> Signed-off-by: Stuart Yoder >> --- >> drivers/char/tpm/Kconfig | 9 + >> drivers/char/tpm/Makefile | 1 + >> drivers/char/tpm/tpm_ffa_crb.c | 310 +++++++++++++++++++++++++++++++++ >> drivers/char/tpm/tpm_ffa_crb.h | 30 ++++ >> 4 files changed, 350 insertions(+) >> create mode 100644 drivers/char/tpm/tpm_ffa_crb.c >> create mode 100644 drivers/char/tpm/tpm_ffa_crb.h >> >> diff --git a/drivers/char/tpm/Kconfig b/drivers/char/tpm/Kconfig >> index 0fc9a510e059..af5ba7c63927 100644 >> --- a/drivers/char/tpm/Kconfig >> +++ b/drivers/char/tpm/Kconfig >> @@ -210,6 +210,15 @@ config TCG_CRB >> from within Linux. To compile this driver as a module, choose >> M here; the module will be called tpm_crb. >> >> +config TCG_ARM_FFA_CRB >> + tristate "TPM CRB over Arm FF-A Transport" >> + depends on ARM_FFA_TRANSPORT >> + default y if (TCG_CRB && ARM_FFA_TRANSPORT) >> + help >> + If the Arm FF-A transport is used to access the TPM say Yes. >> + To compile this driver as a module, choose M here; the module >> + will be called tpm_ffa_crb. >> + >> config TCG_VTPM_PROXY >> tristate "VTPM Proxy Interface" >> depends on TCG_TPM >> diff --git a/drivers/char/tpm/Makefile b/drivers/char/tpm/Makefile >> index 9bb142c75243..21f2eb5a485e 100644 >> --- a/drivers/char/tpm/Makefile >> +++ b/drivers/char/tpm/Makefile >> @@ -42,5 +42,6 @@ obj-$(CONFIG_TCG_IBMVTPM) += tpm_ibmvtpm.o >> obj-$(CONFIG_TCG_TIS_ST33ZP24) += st33zp24/ >> obj-$(CONFIG_TCG_XEN) += xen-tpmfront.o >> obj-$(CONFIG_TCG_CRB) += tpm_crb.o >> +obj-$(CONFIG_TCG_ARM_FFA_CRB) += tpm_ffa_crb.o >> obj-$(CONFIG_TCG_VTPM_PROXY) += tpm_vtpm_proxy.o >> obj-$(CONFIG_TCG_FTPM_TEE) += tpm_ftpm_tee.o >> diff --git a/drivers/char/tpm/tpm_ffa_crb.c b/drivers/char/tpm/tpm_ffa_crb.c >> new file mode 100644 >> index 000000000000..56bd77864a47 >> --- /dev/null >> +++ b/drivers/char/tpm/tpm_ffa_crb.c >> @@ -0,0 +1,310 @@ >> +// SPDX-License-Identifier: GPL-2.0-only >> +/* >> + * Copyright (C) 2024 Arm Ltd. >> + * >> + * Maintained by: >> + * >> + * This device driver implements the TPM CRB start method >> + * as defined in the TPM Service Command Response Buffer >> + * Interface Over FF-A (DEN0138). >> + */ >> + >> +#define pr_fmt(fmt) "FFA_CRB: " fmt >> + >> +#include >> +#include "tpm_ffa_crb.h" >> + >> +/* TPM service function status codes */ >> +#define FFA_CRB_OK 0x05000001 >> +#define FFA_CRB_OK_RESULTS_RETURNED 0x05000002 >> +#define FFA_CRB_NOFUNC 0x8e000001 >> +#define FFA_CRB_NOTSUP 0x8e000002 >> +#define FFA_CRB_INVARG 0x8e000005 >> +#define FFA_CRB_INV_CRB_CTRL_DATA 0x8e000006 >> +#define FFA_CRB_ALREADY 0x8e000009 >> +#define FFA_CRB_DENIED 0x8e00000a >> +#define FFA_CRB_NOMEM 0x8e00000b >> + >> +#define FFA_CRB_VERSION_MAJOR 1 >> +#define FFA_CRB_VERSION_MINOR 0 >> + >> +/* version encoding */ >> +#define FFA_CRB_MAJOR_VERSION_MASK GENMASK(30, 16) >> +#define FFA_CRB_MINOR_VERSION_MASK GENMASK(15, 0) >> +#define FFA_CRB_MAJOR_VERSION(x) ((u16)(FIELD_GET(FFA_CRB_MAJOR_VERSION_MASK, (x)))) >> +#define FFA_CRB_MINOR_VERSION(x) ((u16)(FIELD_GET(FFA_CRB_MINOR_VERSION_MASK, (x)))) >> + >> +/* >> + * Normal world sends requests with FFA_MSG_SEND_DIRECT_REQ and >> + * responses are returned with FFA_MSG_SEND_DIRECT_RESP for normal >> + * messages. >> + * >> + * All requests with FFA_MSG_SEND_DIRECT_REQ and FFA_MSG_SEND_DIRECT_RESP >> + * are using the AArch32 SMC calling convention with register usage as >> + * defined in FF-A specification: >> + * w0: Function ID (0x8400006F or 0x84000070) >> + * w1: Source/Destination IDs >> + * w2: Reserved (MBZ) >> + * w3-w7: Implementation defined, free to be used below >> + */ >> + >> +/* >> + * Returns the version of the interface that is available >> + * Call register usage: >> + * w3: Not used (MBZ) >> + * w4: TPM service function ID, FFA_CRB_GET_INTERFACE_VERSION >> + * w5-w7: Reserved (MBZ) >> + * >> + * Return register usage: >> + * w3: Not used (MBZ) >> + * w4: TPM service function status >> + * w5: TPM service interface version >> + * Bits[31:16]: major version >> + * Bits[15:0]: minor version >> + * w6-w7: Reserved (MBZ) >> + * >> + * Possible function status codes in register w4: >> + * CRB_FFA_OK_RESULTS_RETURNED: The version of the interface has been >> + * returned. >> + */ >> +#define FFA_CRB_GET_INTERFACE_VERSION 0x0f000001 >> + >> +/* >> + * Return information on a given feature of the TPM service >> + * Call register usage: >> + * w3: Not used (MBZ) >> + * w4: TPM service function ID, FFA_CRB_START >> + * w5: Start function qualifier >> + * Bits[31:8] (MBZ) >> + * Bits[7:0] >> + * 0: Notifies TPM that a command is ready to be processed >> + * 1: Notifies TPM that a locality request is ready to be processed >> + * w6: TPM locality, one of 0..4 >> + * -If the start function qualifier is 0, identifies the locality >> + * from where the command originated. >> + * -If the start function qualifier is 1, identifies the locality >> + * of the locality request >> + * w6-w7: Reserved (MBZ) >> + * >> + * Return register usage: >> + * w3: Not used (MBZ) >> + * w4: TPM service function status >> + * w5-w7: Reserved (MBZ) >> + * >> + * Possible function status codes in register w4: >> + * FFA_CRB_OK: the TPM service has been notified successfully >> + * FFA_CRB_INVARG: one or more arguments are not valid >> + * FFA_CRB_INV_CRB_CTRL_DATA: CRB control data or locality control >> + * data at the given TPM locality is not valid >> + * FFA_CRB_DENIED: the TPM has previously disabled locality requests and >> + * command processing at the given locality >> + */ >> +#define FFA_CRB_START 0x0f000201 >> + >> +struct ffa_crb { >> + struct ffa_device *ffa_dev; >> + u16 major_version; >> + u16 minor_version; >> + struct mutex msg_data_lock; >> + struct ffa_send_direct_data direct_msg_data; >> +}; >> + >> +static struct ffa_crb *ffa_crb; >> + >> +static int ffa_crb_to_linux_errno(int errno) >> +{ >> + int rc; >> + >> + switch (errno) { >> + case FFA_CRB_OK: >> + rc = 0; >> + break; >> + case FFA_CRB_OK_RESULTS_RETURNED: >> + rc = 0; >> + break; >> + case FFA_CRB_NOFUNC: >> + rc = -ENOENT; >> + break; >> + case FFA_CRB_NOTSUP: >> + rc = -EPERM; >> + break; >> + case FFA_CRB_INVARG: >> + rc = -EINVAL; >> + break; >> + case FFA_CRB_INV_CRB_CTRL_DATA: >> + rc = -ENOEXEC; >> + break; >> + case FFA_CRB_ALREADY: >> + rc = -EEXIST; >> + break; >> + case FFA_CRB_DENIED: >> + rc = -EACCES; >> + break; >> + case FFA_CRB_NOMEM: >> + rc = -ENOMEM; >> + break; >> + default: >> + rc = -EINVAL; >> + } >> + >> + return rc; >> +} >> + >> +int ffa_crb_init(void) >> +{ >> + if (ffa_crb == NULL) >> + return -ENOENT; >> + >> + if (IS_ERR_VALUE(ffa_crb)) >> + return -ENODEV; >> + >> + return 0; >> +} >> +EXPORT_SYMBOL_GPL(ffa_crb_init); >> + >> +static int __ffa_crb_send_recieve(unsigned long func_id, >> + unsigned long a0, unsigned long a1, unsigned long a2) >> +{ >> + int ret; >> + const struct ffa_msg_ops *msg_ops; >> + >> + if (ffa_crb == NULL) >> + return -ENOENT; >> + >> + msg_ops = ffa_crb->ffa_dev->ops->msg_ops; >> + >> + memset(&ffa_crb->direct_msg_data, 0x00, >> + sizeof(struct ffa_send_direct_data)); >> + >> + ffa_crb->direct_msg_data.data1 = func_id; >> + ffa_crb->direct_msg_data.data2 = a0; >> + ffa_crb->direct_msg_data.data3 = a1; >> + ffa_crb->direct_msg_data.data4 = a2; >> + >> + ret = msg_ops->sync_send_receive(ffa_crb->ffa_dev, >> + &ffa_crb->direct_msg_data); >> + if (!ret) >> + ret = ffa_crb_to_linux_errno(ffa_crb->direct_msg_data.data1); >> + >> + return ret; >> +} >> + >> +int ffa_crb_get_interface_version(uint16_t *major, uint16_t *minor) >> +{ >> + int rc; >> + >> + if (ffa_crb == NULL) >> + return -ENOENT; >> + >> + if (IS_ERR_VALUE(ffa_crb)) >> + return -ENODEV; >> + >> + if (major == NULL || minor == NULL) >> + return -EINVAL; >> + >> + guard(mutex)(&ffa_crb->msg_data_lock); >> + >> + rc = __ffa_crb_send_recieve(FFA_CRB_GET_INTERFACE_VERSION, 0x00, 0x00, 0x00); >> + if (!rc) { >> + *major = FFA_CRB_MAJOR_VERSION(ffa_crb->direct_msg_data.data2); >> + *minor = FFA_CRB_MINOR_VERSION(ffa_crb->direct_msg_data.data2); >> + } >> + >> + return rc; >> +} >> +EXPORT_SYMBOL_GPL(ffa_crb_get_interface_version); >> + >> +int ffa_crb_start(int request_type, int locality) >> +{ >> + if (ffa_crb == NULL) >> + return -ENOENT; >> + >> + if (IS_ERR_VALUE(ffa_crb)) >> + return -ENODEV; >> + >> + guard(mutex)(&ffa_crb->msg_data_lock); >> + >> + return __ffa_crb_send_recieve(FFA_CRB_START, request_type, locality, 0x00); >> +} >> +EXPORT_SYMBOL_GPL(ffa_crb_start); >> + >> +static int ffa_crb_probe(struct ffa_device *ffa_dev) >> +{ >> + int rc; >> + struct ffa_crb *p; >> + >> + /* only one instance of a TPM partition is supported */ >> + if (ffa_crb && !IS_ERR_VALUE(ffa_crb)) >> + return -EEXIST; >> + >> + ffa_crb = ERR_PTR(-ENODEV); // set ffa_crb so we can detect probe failure >> + >> + if (!ffa_partition_supports_direct_recv(ffa_dev)) { >> + pr_err("TPM partition doesn't support direct message receive.\n"); >> + return -EINVAL; >> + } >> + >> + p = kzalloc(sizeof(*ffa_crb), GFP_KERNEL); >> + if (!p) >> + return -ENOMEM; >> + ffa_crb = p; >> + >> + mutex_init(&ffa_crb->msg_data_lock); >> + ffa_crb->ffa_dev = ffa_dev; >> + ffa_dev_set_drvdata(ffa_dev, ffa_crb); >> + >> + /* if TPM is aarch32 use 32-bit SMCs */ >> + if (!ffa_partition_check_property(ffa_dev, FFA_PARTITION_AARCH64_EXEC)) >> + ffa_dev->ops->msg_ops->mode_32bit_set(ffa_dev); >> + >> + /* verify compatibility of TPM service version number */ >> + rc = ffa_crb_get_interface_version(&ffa_crb->major_version, >> + &ffa_crb->minor_version); >> + if (rc) { >> + pr_err("failed to get crb interface version. rc:%d", rc); >> + goto out; >> + } >> + >> + pr_info("ABI version %u.%u", ffa_crb->major_version, >> + ffa_crb->minor_version); >> + >> + if ((ffa_crb->major_version != FFA_CRB_VERSION_MAJOR) || >> + (ffa_crb->minor_version < FFA_CRB_VERSION_MINOR)) { >> + pr_err("Incompatible ABI version"); >> + goto out; >> + } >> + >> + return 0; >> + >> +out: >> + kfree(ffa_crb); >> + ffa_crb = ERR_PTR(-ENODEV); >> + return -EINVAL; >> +} >> + >> +static void ffa_crb_remove(struct ffa_device *ffa_dev) >> +{ >> + kfree(ffa_crb); >> + ffa_crb = NULL; >> +} >> + >> +static const struct ffa_device_id ffa_crb_device_id[] = { >> + /* 17b862a4-1806-4faf-86b3-089a58353861 */ >> + { UUID_INIT(0x17b862a4, 0x1806, 0x4faf, >> + 0x86, 0xb3, 0x08, 0x9a, 0x58, 0x35, 0x38, 0x61) }, >> + {} >> +}; >> + >> +static struct ffa_driver ffa_crb_driver = { >> + .name = "ffa-crb", >> + .probe = ffa_crb_probe, >> + .remove = ffa_crb_remove, >> + .id_table = ffa_crb_device_id, >> +}; >> + >> +module_ffa_driver(ffa_crb_driver); >> + >> +MODULE_AUTHOR("Arm"); >> +MODULE_DESCRIPTION("FFA CRB driver"); >> +MODULE_VERSION("1.0"); >> +MODULE_LICENSE("GPL"); >> diff --git a/drivers/char/tpm/tpm_ffa_crb.h b/drivers/char/tpm/tpm_ffa_crb.h >> new file mode 100644 >> index 000000000000..42327d285165 >> --- /dev/null >> +++ b/drivers/char/tpm/tpm_ffa_crb.h >> @@ -0,0 +1,30 @@ >> +/* SPDX-License-Identifier: GPL-2.0-only */ >> +/* >> + * Copyright (C) 2024 Arm Ltd. >> + * >> + * Authors: >> + * Stuart Yoder >> + * >> + * Maintained by: >> + * >> + * This device driver implements the TPM CRB start method >> + * as defined in the TPM Service Command Response Buffer >> + * Interface Over FF-A (DEN0138). >> + */ >> +#ifndef _FFA_CRB_H >> +#define _FFA_CRB_H >> + >> +#if IS_ENABLED(CONFIG_TCG_ARM_FFA_CRB) >> +int ffa_crb_init(void); >> +int ffa_crb_get_interface_version(uint16_t *major, uint16_t *minor); >> +int ffa_crb_start(int request_type, int locality); >> +#else >> +static inline int ffa_crb_init(void) { return 0; } >> +static inline int ffa_crb_get_interface_version(uint16_t *major, uint16_t *minor) { return 0; } >> +static inline int ffa_crb_start(int request_type, int locality) { return 0; } >> +#endif >> + >> +#define FFA_CRB_START_TYPE_COMMAND 0 >> +#define FFA_CRB_START_TYPE_LOCALITY_REQUEST 1 >> + >> +#endif >> -- >> 2.34.1 >> >> > > tpm_crb_ffa_* I had renamed the source file to be tpm_ffa_crb.c based on your previous feedback. It would be good to be consistent. Would you prefer: tpm_crb_ffa_* or tpm_ffa_crb_* Thanks, Stuart