[PATCH v4 10/33] gpu: nova-core: move firmware image parsing code to firmware.rs

John Hubbard posted 33 patches 22 hours ago
[PATCH v4 10/33] gpu: nova-core: move firmware image parsing code to firmware.rs
Posted by John Hubbard 22 hours ago
Up until now, only the GSP required parsing of its firmware headers.
However, upcoming support for Hopper/Blackwell+ adds another firmware
image (FMC), along with another format (ELF32).

Therefore, the current ELF64 section parsing support needs to be moved
up a level, so that both of the above can use it.

There are no functional changes. This is pure code movement.

Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
---
 drivers/gpu/nova-core/firmware.rs     | 88 +++++++++++++++++++++++++
 drivers/gpu/nova-core/firmware/gsp.rs | 93 ++-------------------------
 2 files changed, 94 insertions(+), 87 deletions(-)

diff --git a/drivers/gpu/nova-core/firmware.rs b/drivers/gpu/nova-core/firmware.rs
index 68779540aa28..a0201ac8ccb4 100644
--- a/drivers/gpu/nova-core/firmware.rs
+++ b/drivers/gpu/nova-core/firmware.rs
@@ -437,3 +437,91 @@ pub(crate) const fn create(
         this.0
     }
 }
+
+/// Ad-hoc and temporary module to extract sections from ELF images.
+///
+/// Some firmware images are currently packaged as ELF files, where sections names are used as keys
+/// to specific and related bits of data. Future firmware versions are scheduled to move away from
+/// that scheme before nova-core becomes stable, which means this module will eventually be
+/// removed.
+mod elf {
+    use core::mem::size_of;
+
+    use kernel::{
+        bindings,
+        str::CStr,
+        transmute::FromBytes, //
+    };
+
+    /// Newtype to provide a [`FromBytes`] implementation.
+    #[repr(transparent)]
+    struct Elf64Hdr(bindings::elf64_hdr);
+    // SAFETY: all bit patterns are valid for this type, and it doesn't use interior mutability.
+    unsafe impl FromBytes for Elf64Hdr {}
+
+    #[repr(transparent)]
+    struct Elf64SHdr(bindings::elf64_shdr);
+    // SAFETY: all bit patterns are valid for this type, and it doesn't use interior mutability.
+    unsafe impl FromBytes for Elf64SHdr {}
+
+    /// Tries to extract section with name `name` from the ELF64 image `elf`, and returns it.
+    pub(super) fn elf64_section<'a, 'b>(elf: &'a [u8], name: &'b str) -> Option<&'a [u8]> {
+        let hdr = &elf
+            .get(0..size_of::<bindings::elf64_hdr>())
+            .and_then(Elf64Hdr::from_bytes)?
+            .0;
+
+        // Get all the section headers.
+        let mut shdr = {
+            let shdr_num = usize::from(hdr.e_shnum);
+            let shdr_start = usize::try_from(hdr.e_shoff).ok()?;
+            let shdr_end = shdr_num
+                .checked_mul(size_of::<Elf64SHdr>())
+                .and_then(|v| v.checked_add(shdr_start))?;
+
+            elf.get(shdr_start..shdr_end)
+                .map(|slice| slice.chunks_exact(size_of::<Elf64SHdr>()))?
+        };
+
+        // Get the strings table.
+        let strhdr = shdr
+            .clone()
+            .nth(usize::from(hdr.e_shstrndx))
+            .and_then(Elf64SHdr::from_bytes)?;
+
+        // Find the section which name matches `name` and return it.
+        shdr.find(|&sh| {
+            let Some(hdr) = Elf64SHdr::from_bytes(sh) else {
+                return false;
+            };
+
+            let Some(name_idx) = strhdr
+                .0
+                .sh_offset
+                .checked_add(u64::from(hdr.0.sh_name))
+                .and_then(|idx| usize::try_from(idx).ok())
+            else {
+                return false;
+            };
+
+            // Get the start of the name.
+            elf.get(name_idx..)
+                .and_then(|nstr| CStr::from_bytes_until_nul(nstr).ok())
+                // Convert into str.
+                .and_then(|c_str| c_str.to_str().ok())
+                // Check that the name matches.
+                .map(|str| str == name)
+                .unwrap_or(false)
+        })
+        // Return the slice containing the section.
+        .and_then(|sh| {
+            let hdr = Elf64SHdr::from_bytes(sh)?;
+            let start = usize::try_from(hdr.0.sh_offset).ok()?;
+            let end = usize::try_from(hdr.0.sh_size)
+                .ok()
+                .and_then(|sh_size| start.checked_add(sh_size))?;
+
+            elf.get(start..end)
+        })
+    }
+}
diff --git a/drivers/gpu/nova-core/firmware/gsp.rs b/drivers/gpu/nova-core/firmware/gsp.rs
index 10761716ed93..173b16cdfb16 100644
--- a/drivers/gpu/nova-core/firmware/gsp.rs
+++ b/drivers/gpu/nova-core/firmware/gsp.rs
@@ -1,5 +1,7 @@
 // SPDX-License-Identifier: GPL-2.0
 
+use core::mem::size_of_val;
+
 use kernel::{
     device,
     dma::{
@@ -16,7 +18,10 @@
 
 use crate::{
     dma::DmaObject,
-    firmware::riscv::RiscvFirmware,
+    firmware::{
+        elf,
+        riscv::RiscvFirmware, //
+    },
     gpu::{
         Architecture,
         Chipset, //
@@ -25,92 +30,6 @@
     num::FromSafeCast,
 };
 
-/// Ad-hoc and temporary module to extract sections from ELF images.
-///
-/// Some firmware images are currently packaged as ELF files, where sections names are used as keys
-/// to specific and related bits of data. Future firmware versions are scheduled to move away from
-/// that scheme before nova-core becomes stable, which means this module will eventually be
-/// removed.
-mod elf {
-    use kernel::{
-        bindings,
-        prelude::*,
-        transmute::FromBytes, //
-    };
-
-    /// Newtype to provide a [`FromBytes`] implementation.
-    #[repr(transparent)]
-    struct Elf64Hdr(bindings::elf64_hdr);
-    // SAFETY: all bit patterns are valid for this type, and it doesn't use interior mutability.
-    unsafe impl FromBytes for Elf64Hdr {}
-
-    #[repr(transparent)]
-    struct Elf64SHdr(bindings::elf64_shdr);
-    // SAFETY: all bit patterns are valid for this type, and it doesn't use interior mutability.
-    unsafe impl FromBytes for Elf64SHdr {}
-
-    /// Tries to extract section with name `name` from the ELF64 image `elf`, and returns it.
-    pub(super) fn elf64_section<'a, 'b>(elf: &'a [u8], name: &'b str) -> Option<&'a [u8]> {
-        let hdr = &elf
-            .get(0..size_of::<bindings::elf64_hdr>())
-            .and_then(Elf64Hdr::from_bytes)?
-            .0;
-
-        // Get all the section headers.
-        let mut shdr = {
-            let shdr_num = usize::from(hdr.e_shnum);
-            let shdr_start = usize::try_from(hdr.e_shoff).ok()?;
-            let shdr_end = shdr_num
-                .checked_mul(size_of::<Elf64SHdr>())
-                .and_then(|v| v.checked_add(shdr_start))?;
-
-            elf.get(shdr_start..shdr_end)
-                .map(|slice| slice.chunks_exact(size_of::<Elf64SHdr>()))?
-        };
-
-        // Get the strings table.
-        let strhdr = shdr
-            .clone()
-            .nth(usize::from(hdr.e_shstrndx))
-            .and_then(Elf64SHdr::from_bytes)?;
-
-        // Find the section which name matches `name` and return it.
-        shdr.find(|&sh| {
-            let Some(hdr) = Elf64SHdr::from_bytes(sh) else {
-                return false;
-            };
-
-            let Some(name_idx) = strhdr
-                .0
-                .sh_offset
-                .checked_add(u64::from(hdr.0.sh_name))
-                .and_then(|idx| usize::try_from(idx).ok())
-            else {
-                return false;
-            };
-
-            // Get the start of the name.
-            elf.get(name_idx..)
-                .and_then(|nstr| CStr::from_bytes_until_nul(nstr).ok())
-                // Convert into str.
-                .and_then(|c_str| c_str.to_str().ok())
-                // Check that the name matches.
-                .map(|str| str == name)
-                .unwrap_or(false)
-        })
-        // Return the slice containing the section.
-        .and_then(|sh| {
-            let hdr = Elf64SHdr::from_bytes(sh)?;
-            let start = usize::try_from(hdr.0.sh_offset).ok()?;
-            let end = usize::try_from(hdr.0.sh_size)
-                .ok()
-                .and_then(|sh_size| start.checked_add(sh_size))?;
-
-            elf.get(start..end)
-        })
-    }
-}
-
 /// GSP firmware with 3-level radix page tables for the GSP bootloader.
 ///
 /// The bootloader expects firmware to be mapped starting at address 0 in GSP's virtual address
-- 
2.53.0