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 HEADgrafted

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.

1 files changed, 210 insertions, 0 deletions

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/<num>.
+
+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_<name>
+------------------
+
+Provides read access to the kernel managed ring buffers for each ring <name>.
+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_<name>
+-----------------
+
+Provides read access to the kernel managed MQD (Memory Queue Descriptor) for
+ring <name> 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_<name>
+-------------------
+
+Provides an interface to set an error code on the dma fences associated with
+ring <name>.  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_<pool>_mm
+----------------
+
+Prints TTM information about the memory pool <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.