linux-stable.git/drivers/gpu/drm/ttm, branch v6.15

drm/ttm: Remove the struct ttm_backup abstraction

2025-05-06T08:57:27+00:00

The abstraction was previously added to support separate
ttm_backup implementations.

However with the current implementation casting from a
struct file to a struct ttm_backup, we run into trouble since
struct file may have randomized the layout and gcc complains.

Remove the struct ttm_backup abstraction

Cc: dri-devel@lists.freedesktop.org
Cc: Matthew Brost 
Cc: Dave Airlie 
Cc: Christian König 
Cc: Matthew Auld 
Cc: Al Viro 
Reported-by: Kees Cook 
Closes: https://lore.kernel.org/dri-devel/9c8dbbafdaf9f3f089da2cde5a772d69579b3795.camel@linux.intel.com/T/#mb153ab9216cb813b92bdeb36f391ad4808c2ba29
Suggested-by: Christian König 
Fixes: 70d645deac98 ("drm/ttm: Add helpers for shrinking")
Signed-off-by: Thomas Hellström 
Reviewed-by: Christian König 
Link: https://lore.kernel.org/r/20250502130014.3156-1-thomas.hellstrom@linux.intel.com

drm/ttm: Fix ttm_backup kerneldoc

2025-05-06T08:57:11+00:00

The docs were not properly updated from an earlier version of the code.

Fixes: e7b5d23e5d47 ("drm/ttm: Provide a shmem backup implementation")
Cc: Christian König 
Cc: Matthew Brost 
Cc: Matthew Auld 
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: Thomas Hellström 
Reviewed-by: Matthew Brost 
Link: https://lore.kernel.org/r/20250502130101.3185-1-thomas.hellstrom@linux.intel.com

drm/ttm: fix the warning for hit_low and evict_low

2025-04-28T08:01:03+00:00

fix the below warning messages:
ttm/ttm_bo.c:1098: warning: Function parameter or struct member 'hit_low' not described in 'ttm_bo_swapout_walk'
ttm/ttm_bo.c:1098: warning: Function parameter or struct member 'evict_low' not described in 'ttm_bo_swapout_walk'

Cc: Maarten Lankhorst 
Cc: Tvrtko Ursulin 
Signed-off-by: Sunil Khatri 
Reviewed-by: Maarten Lankhorst 
Signed-off-by: Christian König 
Link: https://lore.kernel.org/r/20250423042442.762108-1-sunil.khatri@amd.com

drm/ttm: Add helpers for shrinking

2025-03-05T16:08:59+00:00

Add a number of helpers for shrinking that access core TTM and
core MM functionality in a way that make them unsuitable for
driver open-coding.

v11:
- New patch (split off from previous) and additional helpers.
v13:
- Adapt to ttm_backup interface change.
- Take resource off LRU when backed up.

Signed-off-by: Thomas Hellström 
Reviewed-by: Matthew Brost 
Acked-by: Dave Airlie 
Acked-by: Christian König 
Link: https://lore.kernel.org/intel-xe/20250305092220.123405-6-thomas.hellstrom@linux.intel.com

drm/ttm: Add a macro to perform LRU iteration

2025-03-05T16:08:59+00:00

Following the design direction communicated here:

https://lore.kernel.org/linux-mm/b7491378-defd-4f1c-31e2-29e4c77e2d67@amd.com/T/#ma918844aa8a6efe8768fdcda0c6590d5c93850c9

Export a LRU walker for driver shrinker use. The walker
initially supports only trylocking, since that's the
method used by shrinkes. The walker makes use of
scoped_guard() to allow exiting from the LRU walk loop
without performing any explicit unlocking or
cleanup.

v8:
- Split out from another patch.
- Use a struct for bool arguments to increase readability (Matt Brost).
- Unmap user-space cpu-mappings before shrinking pages.
- Explain non-fatal error codes (Matt Brost)

v10:
- Instead of using the existing helper, Wrap the interface inside out and
  provide a loop to de-midlayer things the LRU iteration (Christian König).
- Removing the R-B by Matt Brost since the patch was significantly changed.

v11:
- Split the patch up to include just the LRU walk helper.

v12:
- Indent after scoped_guard() (Matt Brost)

v15:
- Adapt to new definition of scoped_guard()

Signed-off-by: Thomas Hellström 
Reviewed-by: Matthew Brost 
Acked-by: Dave Airlie 
Acked-by: Christian König 
Link: https://lore.kernel.org/intel-xe/20250305092220.123405-5-thomas.hellstrom@linux.intel.com

drm/ttm: Use fault-injection to test error paths

2025-03-05T16:08:59+00:00

Use fault-injection to test partial TTM swapout and interrupted swapin.
Return -EINTR for swapin to test the callers ability to handle and
restart the swapin, and on swapout perform a partial swapout to test that
the swapin and release_shrunken functionality.

v8:
- Use the core fault-injection system.
v9:
- Fix compliation failure for !CONFIG_FAULT_INJECTION

Cc: Christian König 
Cc: Somalapuram Amaranath 
Cc: Matthew Brost 
Cc: 
Signed-off-by: Thomas Hellström 
Reviewed-by: Matthew Brost 
Reviewed-by: Christian König 
Link: https://lore.kernel.org/intel-xe/20250305092220.123405-4-thomas.hellstrom@linux.intel.com

drm/ttm/pool, drm/ttm/tt: Provide a helper to shrink pages

2025-03-05T16:08:59+00:00

Provide a helper to shrink ttm_tt page-vectors on a per-page
basis. A ttm_backup backend could then in theory get away with
allocating a single temporary page for each struct ttm_tt.

This is accomplished by splitting larger pages before trying to
back them up.

In the future we could allow ttm_backup to handle backing up
large pages as well, but currently there's no benefit in
doing that, since the shmem backup backend would have to
split those anyway to avoid allocating too much temporary
memory, and if the backend instead inserts pages into the
swap-cache, those are split on reclaim by the core.

Due to potential backup- and recover errors, allow partially swapped
out struct ttm_tt's, although mark them as swapped out stopping them
from being swapped out a second time. More details in the ttm_pool.c
DOC section.

v2:
- A couple of cleanups and error fixes in ttm_pool_back_up_tt.
- s/back_up/backup/
- Add a writeback parameter to the exported interface.
v8:
- Use a struct for flags for readability (Matt Brost)
- Address misc other review comments (Matt Brost)
v9:
- Update the kerneldoc for the ttm_tt::backup field.
v10:
- Rebase.
v13:
- Rebase on ttm_backup interface change. Update kerneldoc.
- Rebase and adjust ttm_tt_is_swapped().
v15:
- Rebase on ttm_backup return value change.
- Rebase on previous restructuring of ttm_pool_alloc()
- Rework the ttm_pool backup interface (Christian König)
- Remove cond_resched() (Christian König)
- Get rid of the need to allocate an intermediate page array
  when restoring a multi-order page (Christian König)
- Update documentation.

Cc: Christian König 
Cc: Somalapuram Amaranath 
Cc: Matthew Brost 
Cc: 
Signed-off-by: Thomas Hellström 
Reviewed-by: Matthew Brost 
Acked-by: Christian Koenig 
Link: https://lore.kernel.org/intel-xe/20250305092220.123405-3-thomas.hellstrom@linux.intel.com

drm/ttm: Provide a shmem backup implementation

2025-03-05T16:08:59+00:00

Provide a standalone shmem backup implementation.
Given the ttm_backup interface, this could
later on be extended to providing other backup
implementation than shmem, with one use-case being
GPU swapout to a user-provided fd.

v5:
- Fix a UAF. (kernel test robot, Dan Carptenter)
v6:
- Rename ttm_backup_shmem_copy_page() function argument
  (Matthew Brost)
- Add some missing documentation
v8:
- Use folio_file_page to get to the page we want to writeback
  instead of using the first page of the folio.
v13:
- Remove the base class abstraction (Christian König)
- Include ttm_backup_bytes_avail().
v14:
- Fix kerneldoc for ttm_backup_bytes_avail() (0-day)
- Work around casting of __randomize_layout struct pointer (0-day)
v15:
- Return negative error code from ttm_backup_backup_page()
  (Christian König)
- Doc fixes. (Christian König).

Cc: Christian König 
Cc: Somalapuram Amaranath 
Cc: Matthew Brost 
Cc: 
Signed-off-by: Thomas Hellström 
Reviewed-by: Matthew Brost 
Reviewed-by: Christian König 
Link: https://lore.kernel.org/intel-xe/20250305092220.123405-2-thomas.hellstrom@linux.intel.com

drm/ttm: use ttm_resource_unevictable() to replace pin_count and swapped

2025-02-10T12:39:03+00:00

TTM always uses pin_count and ttm_resource_is_swapped() together to
determine whether a BO is unevictable.
Now use ttm_resource_unevictable() to replace them.

Signed-off-by: Zhaoyu Liu 
Reviewed-by: Christian König 
Link: https://patchwork.freedesktop.org/patch/msgid/20250126093256.GA688734@bytedance
Signed-off-by: Christian König

Merge drm/drm-next into drm-misc-next

2025-02-06T12:47:32+00:00

Bring rc1 to start the new release dev.

Signed-off-by: Maxime Ripard