[PATCH 2/7] gpu: nova-core: place the generic bootloader at the top of IMEM

[Alexandre Courbot <acourbot@nvidia.com>]

From: John Hubbard <jhubbard@nvidia.com>

The generic bootloader was loaded right below the first 64 KiB of IMEM,
on the assumption that every falcon it runs on has a 64 KiB IMEM. The
r000 load-and-execute bootloader event can name any image for it to
load, and the bootloader must then sit above the blocks that the image
occupies, that is, in the last blocks of IMEM, regardless of its size.

Place the bootloader at the top of the falcon's IMEM, using the IMEM
size that the HWCFG register reports, instead of assuming a 64 KiB IMEM.

Assisted-by: LLM
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: Timur Tabi <ttabi@nvidia.com>
Reviewed-by: Zhi Wang <zhiw@nvidia.com>
[acourbot: split out of the patch separating the bootloader from FWSEC;
 convert the IMEM size with usize::from()]
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
---
 drivers/gpu/nova-core/falcon.rs                    |  7 +++++++
 drivers/gpu/nova-core/firmware/fwsec/bootloader.rs |  3 ++-
 drivers/gpu/nova-core/firmware/gen_bootloader.rs   | 23 +++++++++++++---------
 drivers/gpu/nova-core/gsp/hal/tu102.rs             |  6 ++++--
 drivers/gpu/nova-core/regs.rs                      |  5 +++++
 5 files changed, 32 insertions(+), 12 deletions(-)

diff --git a/drivers/gpu/nova-core/falcon.rs b/drivers/gpu/nova-core/falcon.rs
index 0b377bd6524a..1bceb38c33c6 100644
--- a/drivers/gpu/nova-core/falcon.rs
+++ b/drivers/gpu/nova-core/falcon.rs
@@ -382,6 +382,13 @@ pub(crate) fn new(
         })
     }
 
+    /// Returns the size of this falcon's IMEM in bytes.
+    pub(crate) fn imem_size(&self) -> usize {
+        let blocks = usize::from(self.pfalcon.read(regs::NV_PFALCON_FALCON_HWCFG).imem_size());
+
+        blocks * MEM_BLOCK_ALIGNMENT
+    }
+
     /// Resets DMA-related registers.
     pub(crate) fn dma_reset(&self) {
         self.pfalcon.update(regs::NV_PFALCON_FBIF_CTL, |v| {
diff --git a/drivers/gpu/nova-core/firmware/fwsec/bootloader.rs b/drivers/gpu/nova-core/firmware/fwsec/bootloader.rs
index 59f57714fcfb..3943948d74bc 100644
--- a/drivers/gpu/nova-core/firmware/fwsec/bootloader.rs
+++ b/drivers/gpu/nova-core/firmware/fwsec/bootloader.rs
@@ -108,8 +108,9 @@ pub(crate) fn new(
         firmware: FwsecFirmware,
         dev: &'a Device<device::Bound>,
         chipset: Chipset,
+        falcon: &Falcon<'_, Gsp>,
     ) -> Result<Self> {
-        let bootloader = GenericBootloader::new(dev, chipset)?;
+        let bootloader = GenericBootloader::new(dev, chipset, falcon)?;
 
         // `BootloaderDmemDescV2` expects the source to be a mirror image of the destination and
         // uses the same offset parameter for both.
diff --git a/drivers/gpu/nova-core/firmware/gen_bootloader.rs b/drivers/gpu/nova-core/firmware/gen_bootloader.rs
index b1ed6c2ccf7d..d51948c6a2b8 100644
--- a/drivers/gpu/nova-core/firmware/gen_bootloader.rs
+++ b/drivers/gpu/nova-core/firmware/gen_bootloader.rs
@@ -8,13 +8,14 @@
 use kernel::{
     device,
     prelude::*,
-    ptr::Alignable,
-    sizes, //
+    ptr::Alignable, //
 };
 
 use crate::{
     falcon::{
         self,
+        gsp::Gsp,
+        Falcon,
         FalconPioImemLoadTarget, //
     },
     firmware::tlv::{
@@ -36,15 +37,19 @@ pub(crate) struct GenericBootloader {
 }
 
 impl GenericBootloader {
-    /// Loads the generic bootloader image for `chipset`, placed right below the first 64 KiB of
-    /// IMEM.
+    /// Loads the generic bootloader image for `chipset`, placed in the last blocks of an IMEM of
+    /// `imem_size` bytes.
     ///
     /// # Errors
     ///
     /// - `EINVAL` if a required TLV field is absent.
-    /// - `EOVERFLOW` if the image does not fit below 64 KiB.
+    /// - `EOVERFLOW` if the image does not fit in IMEM.
     /// - `ENOMEM` if the padded copy of the code cannot be allocated.
-    pub(crate) fn new(dev: &device::Device<device::Bound>, chipset: Chipset) -> Result<Self> {
+    pub(crate) fn new(
+        dev: &device::Device<device::Bound>,
+        chipset: Chipset,
+        falcon: &Falcon<'_, Gsp>,
+    ) -> Result<Self> {
         let fw = request_tlv(dev, chipset, "gen_bootloader")?;
         let tlv = Tlv::new(fw.data())?;
         dev_dbg!(
@@ -68,9 +73,9 @@ pub(crate) fn new(dev: &device::Device<device::Bound>, chipset: Chipset) -> Resu
             ucode
         };
 
-        // The bootloader's code must be loaded in the area right below the first 64K of IMEM.
-        const BOOTLOADER_LOAD_CEILING: usize = sizes::SZ_64K;
-        let imem_dst_start = BOOTLOADER_LOAD_CEILING
+        // The top of IMEM, above the blocks that the bootloader loads the image into.
+        let imem_dst_start = falcon
+            .imem_size()
             .checked_sub(ucode.len())
             .ok_or(EOVERFLOW)?;
 
diff --git a/drivers/gpu/nova-core/gsp/hal/tu102.rs b/drivers/gpu/nova-core/gsp/hal/tu102.rs
index e90db1a23032..1b17ece53bd6 100644
--- a/drivers/gpu/nova-core/gsp/hal/tu102.rs
+++ b/drivers/gpu/nova-core/gsp/hal/tu102.rs
@@ -165,7 +165,7 @@ fn run_fwsec_frts(
         )?;
 
         if self.needs_fwsec_bootloader {
-            let fwsec_frts_bl = FwsecFirmwareWithBl::new(fwsec_frts, dev, chipset)?;
+            let fwsec_frts_bl = FwsecFirmwareWithBl::new(fwsec_frts, dev, chipset, falcon)?;
             // Load and run the bootloader, which will load FWSEC-FRTS and run it.
             fwsec_frts_bl.run(dev, falcon)?;
         } else {
@@ -223,7 +223,9 @@ fn build_unload_bundle<'gpu>(
         // Load the FWSEC SB firmware, as well as its bootloader if required.
         let fwsec_sb = FwsecFirmware::new(dev, gsp_falcon, bios, FwsecCommand::Sb)?;
         let fwsec_sb = if self.needs_fwsec_bootloader {
-            FwsecUnloadFirmware::WithBl(FwsecFirmwareWithBl::new(fwsec_sb, dev, chipset)?)
+            FwsecUnloadFirmware::WithBl(FwsecFirmwareWithBl::new(
+                fwsec_sb, dev, chipset, gsp_falcon,
+            )?)
         } else {
             FwsecUnloadFirmware::WithoutBl(fwsec_sb)
         };
diff --git a/drivers/gpu/nova-core/regs.rs b/drivers/gpu/nova-core/regs.rs
index 88662da634dc..b7070282d692 100644
--- a/drivers/gpu/nova-core/regs.rs
+++ b/drivers/gpu/nova-core/regs.rs
@@ -181,6 +181,11 @@ pub(crate) fn usable_fb_size(self) -> u64 {
         31:0    value => u32;
     }
 
+    pub(crate) NV_PFALCON_FALCON_HWCFG(u32) @ 0x00000108 {
+        /// Number of 256-byte blocks in this falcon's IMEM.
+        8:0     imem_size;
+    }
+
     pub(crate) NV_PFALCON_FALCON_DMACTL(u32) @ 0x0000010c {
         7:7     secure_stat => bool;
         6:3     dmaq_num;

-- 
2.56.0