From 9cc63f8bcd560c760d0b12e15bba8f81c86237cf Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Fri, 14 Aug 2026 15:43:51 -0700 Subject: Merge branches 'expcb.2026.07.24a', 'misc.2026.07.30a', 'rcu-tasks.2026.07.30a', 'srcu.2026.08.11a' and 'torture.2026.08.14a' into HEAD Changes: Make expedited grace periods expedite normal RCU callbacks Miscellaneous fixes: * Improve diagnostic output with character task states. * Mark accesses to inform KCSAN of concurrency design. * Move from kmalloc() to kmalloc_obj(). * Documentation updates. * Improve handling of RCU deferred quiescent states. * Clean up unused function arguments and structure fields. * Reduce show_rcu_gp_kthreads() stack space. Tasks RCU updates: * Clean up after SRCU re-implementation of Tasks Trace RCU. * Mark accesses to inform KCSAN of concurrency design. * Add ->lazy_timer status to diagnostic output. * Remove an unnecessary memory barrier. * Fix a data race, courtesy of KCSAN. * Documentation updates. * Convert cond_resched_tasks_rcu_qs() from macro to static inline function. SRCU updates: * Add Rust helpers for SRCU. * Avoid losing queued work at cleanup_srcu_struct() time. Torture-test updates: * Preparation work for immediate RCU priority deboosting. * Test RCU readers from real interrupt handlers (as opposed to softirq). * Simplify code through use of cpumask_next_wrap(). * Improve diagnostic output with character task states. * Add rcutorture.nwriters parameter to allow lightweight stall testing, and rcutorture.stall_only to make doing so easier. * Test an RCU Tasks Trace grace period implying an RCU grace period. * Make RCU Tasks Trace torturing track reader batches. * Fix a data race, courtesy of KCSAN. * Plug a shuffle_tmp_mask memory leak on kthread spawn failure. --- Documentation/gpu/amdgpu/debugfs.rst | 210 +++++++++++++++++++++++++++++++++++ 1 file changed, 210 insertions(+) create mode 100644 Documentation/gpu/amdgpu/debugfs.rst (limited to 'Documentation/gpu/amdgpu/debugfs.rst') diff --git a/Documentation/gpu/amdgpu/debugfs.rst b/Documentation/gpu/amdgpu/debugfs.rst new file mode 100644 index 000000000..151d8bfc7 --- /dev/null +++ b/Documentation/gpu/amdgpu/debugfs.rst @@ -0,0 +1,210 @@ +============== +AMDGPU DebugFS +============== + +The amdgpu driver provides a number of debugfs files to aid in debugging +issues in the driver. These are usually found in +/sys/kernel/debug/dri/. + +DebugFS Files +============= + +amdgpu_benchmark +---------------- + +Run benchmarks using the DMA engine the driver uses for GPU memory paging. +Write a number to the file to run the test. The results are written to the +kernel log. VRAM is on device memory (dGPUs) or carve out (APUs) and GTT +(Graphics Translation Tables) is system memory that is accessible by the GPU. +The following tests are available: + +- 1: simple test, VRAM to GTT and GTT to VRAM +- 2: simple test, VRAM to VRAM +- 3: GTT to VRAM, buffer size sweep, powers of 2 +- 4: VRAM to GTT, buffer size sweep, powers of 2 +- 5: VRAM to VRAM, buffer size sweep, powers of 2 +- 6: GTT to VRAM, buffer size sweep, common display sizes +- 7: VRAM to GTT, buffer size sweep, common display sizes +- 8: VRAM to VRAM, buffer size sweep, common display sizes + +amdgpu_test_ib +-------------- + +Read this file to run simple IB (Indirect Buffer) tests on all kernel managed +rings. IBs are command buffers usually generated by userspace applications +which are submitted to the kernel for execution on an particular GPU engine. +This just runs the simple IB tests included in the kernel. These tests +are engine specific and verify that IB submission works. + +amdgpu_discovery +---------------- + +Provides raw access to the IP discovery binary provided by the GPU. Read this +file to access the raw binary. This is useful for verifying the contents of +the IP discovery table. It is chip specific. + +amdgpu_vbios +------------ + +Provides raw access to the ROM binary image from the GPU. Read this file to +access the raw binary. This is useful for verifying the contents of the +video BIOS ROM. It is board specific. + +amdgpu_evict_gtt +---------------- + +Evict all buffers from the GTT memory pool. Read this file to evict all +buffers from this pool. + +amdgpu_evict_vram +----------------- + +Evict all buffers from the VRAM memory pool. Read this file to evict all +buffers from this pool. + +amdgpu_gpu_recover +------------------ + +Trigger a GPU reset. Read this file to trigger reset the entire GPU. +All work currently running on the GPU will be lost. + +amdgpu_ring_ +------------------ + +Provides read access to the kernel managed ring buffers for each ring . +These are useful for debugging problems on a particular ring. The ring buffer +is how the CPU sends commands to the GPU. The CPU writes commands into the +buffer and then asks the GPU engine to process it. This is the raw binary +contents of the ring buffer. Use a tool like UMR to decode the rings into human +readable form. + +amdgpu_mqd_ +----------------- + +Provides read access to the kernel managed MQD (Memory Queue Descriptor) for +ring managed by the kernel driver. MQDs define the features of the ring +and are used to store the ring's state when it is not connected to hardware. +The driver writes the requested ring features and metadata (GPU addresses of +the ring itself and associated buffers) to the MQD and the firmware uses the MQD +to populate the hardware when the ring is mapped to a hardware slot. Only +available on engines which use MQDs. This provides access to the raw MQD +binary. + +amdgpu_error_ +------------------- + +Provides an interface to set an error code on the dma fences associated with +ring . The error code specified is propagated to all fences associated +with the ring. Use this to inject a fence error into a ring. + +amdgpu_pm_info +-------------- + +Provides human readable information about the power management features +and state of the GPU. This includes current GFX clock, Memory clock, +voltages, average SoC power, temperature, GFX load, Memory load, SMU +feature mask, VCN power state, clock and power gating features. + +amdgpu_firmware_info +-------------------- + +Lists the firmware versions for all firmwares used by the GPU. Only +entries with a non-0 version are valid. If the version is 0, the firmware +is not valid for the GPU. + +amdgpu_fence_info +----------------- + +Shows the last signalled and emitted fence sequence numbers for each +kernel driver managed ring. Fences are associated with submissions +to the engine. Emitted fences have been submitted to the ring +and signalled fences have been signalled by the GPU. Rings with a +larger emitted fence value have outstanding work that is still being +processed by the engine that owns that ring. When the emitted and +signalled fence values are equal, the ring is idle. + +amdgpu_gem_info +--------------- + +Lists all of the PIDs using the GPU and the GPU buffers that they have +allocated. This lists the buffer size, pool (VRAM, GTT, etc.), and buffer +attributes (CPU access required, CPU cache attributes, etc.). + +amdgpu_vm_info +-------------- + +Lists all of the PIDs using the GPU and the GPU buffers that they have +allocated as well as the status of those buffers relative to that process' +GPU virtual address space (e.g., evicted, idle, invalidated, etc.). + +amdgpu_sa_info +-------------- + +Prints out all of the suballocations (sa) by the suballocation manager in the +kernel driver. Prints the GPU address, size, and fence info associated +with each suballocation. The suballocations are used internally within +the kernel driver for various things. + +amdgpu__mm +---------------- + +Prints TTM information about the memory pool . + +amdgpu_vram +----------- + +Provides direct access to VRAM. Used by tools like UMR to inspect +objects in VRAM. + +amdgpu_iomem +------------ + +Provides direct access to GTT memory. Used by tools like UMR to inspect +GTT memory. + +amdgpu_regs_* +------------- + +Provides direct access to various register apertures on the GPU. Used +by tools like UMR to access GPU registers. + +amdgpu_regs2 +------------ + +Provides an IOCTL interface used by UMR for interacting with GPU registers. + + +amdgpu_sensors +-------------- + +Provides an interface to query GPU power metrics (temperature, average +power, etc.). Used by tools like UMR to query GPU power metrics. + + +amdgpu_gca_config +----------------- + +Provides an interface to query GPU details (Graphics/Compute Array config, +PCI config, GPU family, etc.). Used by tools like UMR to query GPU details. + +amdgpu_wave +----------- + +Used to query GFX/compute wave information from the hardware. Used by tools +like UMR to query GFX/compute wave information. + +amdgpu_gpr +---------- + +Used to query GFX/compute GPR (General Purpose Register) information from the +hardware. Used by tools like UMR to query GPRs when debugging shaders. + +amdgpu_gprwave +-------------- + +Provides an IOCTL interface used by UMR for interacting with shader waves. + +amdgpu_fw_attestation +--------------------- + +Provides an interface for reading back firmware attestation records. -- cgit v1.3.1