From 5febf432df1cfa5b25d99b54c32103fafbdd0eb9 Mon Sep 17 00:00:00 2001 From: Miguel Ojeda Date: Sun, 16 Aug 2026 15:32:33 +0200 Subject: kbuild: rust: keep Rust objects out of Clang LTO with inline helpers Under `CONFIG_LTO_CLANG` + `CONFIG_RUST_INLINE_HELPERS`, one may hit `objtool` errors such as: vmlinux.o: error: objtool: _R..._3Gsp4boot+0xd6a: can't find jump dest instruction at .text._R..._3Gsp4boot+0x1dfd The reason is that in such builds, the Clang invocation that compiles the combined Rust plus helpers bitcode emits LLVM bitcode (again) -- the final code generation happens in the linker's LTO step, which the `-mllvm` trap options passed to Clang do not reach. This, in turn, means that unreachable traps are missing, and the impossible paths do not merely fallthrough to the next symbol, but past the end of their own section, since LTO builds place each function in its own section. Thus filter `CC_FLAGS_LTO` out of the Clang invocation, so that it always emits machine code directly, with the traps in place. Assisted-by: LLM Cc: Gary Guo Cc: Boqun Feng Cc: Alice Ryhl Cc: Matthew Maurer Cc: Josh Poimboeuf Cc: Peter Zijlstra Cc: stable@vger.kernel.org Fixes: 3a2486cc1da5 ("kbuild: rust: provide an option to inline C helpers into Rust") Acked-by: Gary Guo Link: https://patch.msgid.link/20260816133233.197500-2-ojeda@kernel.org Signed-off-by: Miguel Ojeda --- Documentation/gpu/amdgpu/flashing.rst | 33 +++++++++++++++++++++++++++++++++ 1 file changed, 33 insertions(+) create mode 100644 Documentation/gpu/amdgpu/flashing.rst (limited to 'Documentation/gpu/amdgpu/flashing.rst') diff --git a/Documentation/gpu/amdgpu/flashing.rst b/Documentation/gpu/amdgpu/flashing.rst new file mode 100644 index 000000000..bd745c42a --- /dev/null +++ b/Documentation/gpu/amdgpu/flashing.rst @@ -0,0 +1,33 @@ +======================= + dGPU firmware flashing +======================= + +IFWI +---- +Flashing the dGPU integrated firmware image (IFWI) is supported by GPUs that +use the PSP to orchestrate the update (Navi3x or newer GPUs). +For supported GPUs, `amdgpu` will export a series of sysfs files that can be +used for the flash process. + +The IFWI flash process is: + +1. Ensure the IFWI image is intended for the dGPU on the system. +2. "Write" the IFWI image to the sysfs file `psp_vbflash`. This will stage the IFWI in memory. +3. "Read" from the `psp_vbflash` sysfs file to initiate the flash process. +4. Poll the `psp_vbflash_status` sysfs file to determine when the flash process completes. + +USB-C PD F/W +------------ +On GPUs that support flashing an updated USB-C PD firmware image, the process +is done using the `usbc_pd_fw` sysfs file. + +* Reading the file will provide the current firmware version. +* Writing the name of a firmware payload stored in `/lib/firmware/amdgpu` to the sysfs file will initiate the flash process. + +The firmware payload stored in `/lib/firmware/amdgpu` can be named any name +as long as it doesn't conflict with other existing binaries that are used by +`amdgpu`. + +sysfs files +----------- +.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_psp.c -- cgit v1.3.1