linux-stable.git/include/drm/ttm, branch v6.15 Linux kernel stable tree drm/ttm: Remove the struct ttm_backup abstraction 2025-05-06T08:57:27+00:00 Thomas Hellström thomas.hellstrom@linux.intel.com 2025-05-02T13:00:14+00:00 d4ad53adfe21df1464bae5ed916085a69d6ffb3d 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 <matthew.brost@intel.com> Cc: Dave Airlie <airlied@redhat.com> Cc: Christian König <christian.koenig@amd.com> Cc: Matthew Auld <matthew.auld@intel.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Reported-by: Kees Cook <kees@kernel.org> Closes: https://lore.kernel.org/dri-devel/9c8dbbafdaf9f3f089da2cde5a772d69579b3795.camel@linux.intel.com/T/#mb153ab9216cb813b92bdeb36f391ad4808c2ba29 Suggested-by: Christian König <christian.koenig@amd.com> Fixes: 70d645deac98 ("drm/ttm: Add helpers for shrinking") Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com> Reviewed-by: Christian König <christian.koenig@amd.com> Link: https://lore.kernel.org/r/20250502130014.3156-1-thomas.hellstrom@linux.intel.com 
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 <matthew.brost@intel.com>
Cc: Dave Airlie <airlied@redhat.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Reported-by: Kees Cook <kees@kernel.org>
Closes: https://lore.kernel.org/dri-devel/9c8dbbafdaf9f3f089da2cde5a772d69579b3795.camel@linux.intel.com/T/#mb153ab9216cb813b92bdeb36f391ad4808c2ba29
Suggested-by: Christian König <christian.koenig@amd.com>
Fixes: 70d645deac98 ("drm/ttm: Add helpers for shrinking")
Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
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 Thomas Hellström thomas.hellstrom@linux.intel.com 2025-05-02T13:01:01+00:00 2bb04ea9e5b7a2ef583c042ed5f8111804606e9d 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 <christian.koenig@amd.com> Cc: Matthew Brost <matthew.brost@intel.com> Cc: Matthew Auld <matthew.auld@intel.com> Cc: dri-devel@lists.freedesktop.org Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com> Reviewed-by: Matthew Brost <matthew.brost@intel.com> Link: https://lore.kernel.org/r/20250502130101.3185-1-thomas.hellstrom@linux.intel.com 
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 <christian.koenig@amd.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Link: https://lore.kernel.org/r/20250502130101.3185-1-thomas.hellstrom@linux.intel.com
drm/ttm: Add helpers for shrinking 2025-03-05T16:08:59+00:00 Thomas Hellström thomas.hellstrom@linux.intel.com 2025-03-05T09:22:18+00:00 70d645deac98303d1bf9ab08a4e68da52bf8c1e1 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 <thomas.hellstrom@linux.intel.com> Reviewed-by: Matthew Brost <matthew.brost@intel.com> Acked-by: Dave Airlie <airlied@redhat.com> Acked-by: Christian König <christian.koenig@amd.com> Link: https://lore.kernel.org/intel-xe/20250305092220.123405-6-thomas.hellstrom@linux.intel.com 
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 <thomas.hellstrom@linux.intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Acked-by: Dave Airlie <airlied@redhat.com>
Acked-by: Christian König <christian.koenig@amd.com>
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 Thomas Hellström thomas.hellstrom@linux.intel.com 2025-03-05T09:22:17+00:00 f3bcfd04a52fb1b1702349bed2bccc1126b97f89 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 <thomas.hellstrom@linux.intel.com> Reviewed-by: Matthew Brost <matthew.brost@intel.com> Acked-by: Dave Airlie <airlied@redhat.com> Acked-by: Christian König <christian.koenig@amd.com> Link: https://lore.kernel.org/intel-xe/20250305092220.123405-5-thomas.hellstrom@linux.intel.com 
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 <thomas.hellstrom@linux.intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Acked-by: Dave Airlie <airlied@redhat.com>
Acked-by: Christian König <christian.koenig@amd.com>
Link: https://lore.kernel.org/intel-xe/20250305092220.123405-5-thomas.hellstrom@linux.intel.com
drm/ttm/pool, drm/ttm/tt: Provide a helper to shrink pages 2025-03-05T16:08:59+00:00 Thomas Hellström thomas.hellstrom@linux.intel.com 2025-03-05T09:22:15+00:00 b63d715b8090aed48bdef5930625946fa4c0d324 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 <christian.koenig@amd.com> Cc: Somalapuram Amaranath <Amaranath.Somalapuram@amd.com> Cc: Matthew Brost <matthew.brost@intel.com> Cc: <dri-devel@lists.freedesktop.org> Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com> Reviewed-by: Matthew Brost <matthew.brost@intel.com> Acked-by: Christian Koenig <christian.koenig@amd.com> Link: https://lore.kernel.org/intel-xe/20250305092220.123405-3-thomas.hellstrom@linux.intel.com 
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 <christian.koenig@amd.com>
Cc: Somalapuram Amaranath <Amaranath.Somalapuram@amd.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: <dri-devel@lists.freedesktop.org>
Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Acked-by: Christian Koenig <christian.koenig@amd.com>
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 Thomas Hellström thomas.hellstrom@linux.intel.com 2025-03-05T09:22:14+00:00 e7b5d23e5d4705ae93ef6af891b7b7bcccbe1257 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 <christian.koenig@amd.com> Cc: Somalapuram Amaranath <Amaranath.Somalapuram@amd.com> Cc: Matthew Brost <matthew.brost@intel.com> Cc: <dri-devel@lists.freedesktop.org> Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com> Reviewed-by: Matthew Brost <matthew.brost@intel.com> Reviewed-by: Christian König <christian.koenig@amd.com> Link: https://lore.kernel.org/intel-xe/20250305092220.123405-2-thomas.hellstrom@linux.intel.com 
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 <christian.koenig@amd.com>
Cc: Somalapuram Amaranath <Amaranath.Somalapuram@amd.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: <dri-devel@lists.freedesktop.org>
Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Link: https://lore.kernel.org/intel-xe/20250305092220.123405-2-thomas.hellstrom@linux.intel.com
Merge drm/drm-next into drm-misc-next 2025-02-06T12:47:32+00:00 Maxime Ripard mripard@kernel.org 2025-02-06T12:47:32+00:00 93c7dd1b39444ebd5a6a98e56a363d7a4e646775 Bring rc1 to start the new release dev. Signed-off-by: Maxime Ripard <mripard@kernel.org> 
Bring rc1 to start the new release dev.

Signed-off-by: Maxime Ripard <mripard@kernel.org>
drm/ttm: Balance ttm_resource_cursor_init() and ttm_resource_cursor_fini() 2025-01-13T11:58:10+00:00 Thomas Hellström thomas.hellstrom@linux.intel.com 2024-12-17T14:58:44+00:00 1f463794097dcdf4c64fffd31de2177681525e35 Make the interface more symmetric by providing and using a ttm_resource_cursor_init(). v10: - Fix a stray newline (Matthew Brost) - Update kerneldoc (Matthew Brost) Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com> Reviewed-by: Matthew Brost <matthew.brost@intel.com> Reviewed-by: Christian König <christian.koenig@amd.com> Link: https://patchwork.freedesktop.org/patch/msgid/20241217145852.37342-2-thomas.hellstrom@linux.intel.com Signed-off-by: Christian König <christian.koenig@amd.com> 
Make the interface more symmetric by providing and using a
ttm_resource_cursor_init().

v10:
- Fix a stray newline (Matthew Brost)
- Update kerneldoc (Matthew Brost)

Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20241217145852.37342-2-thomas.hellstrom@linux.intel.com
Signed-off-by: Christian König <christian.koenig@amd.com>
Merge tag 'cgroup-dmem-drm-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/mripard/linux into drm-next 2025-01-10T21:20:29+00:00 Dave Airlie airlied@redhat.com 2025-01-10T21:20:22+00:00 39388d53c57be95eafb0ce1d81d0ec6bd2f6f42d DMEM cgroup pull request This introduces a new cgroup controller to limit the device memory. Notable users would be DRM, dma-buf heaps, or v4l2. This pull request is based on the series developped by Maarten Lankhorst, Friedrich Vock, and I: https://lore.kernel.org/all/20241204134410.1161769-1-dev@lankhorst.se/ Signed-off-by: Dave Airlie <airlied@redhat.com> From: Maxime Ripard <mripard@redhat.com> Link: https://patchwork.freedesktop.org/patch/msgid/20250110-cryptic-warm-mandrill-b71f5d@houat 
DMEM cgroup pull request

This introduces a new cgroup controller to limit the device memory.
Notable users would be DRM, dma-buf heaps, or v4l2.

This pull request is based on the series developped by Maarten
Lankhorst, Friedrich Vock, and I:
https://lore.kernel.org/all/20241204134410.1161769-1-dev@lankhorst.se/

Signed-off-by: Dave Airlie <airlied@redhat.com>

From: Maxime Ripard <mripard@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250110-cryptic-warm-mandrill-b71f5d@houat
drm/ttm: Handle cgroup based eviction in TTM 2025-01-10T08:54:49+00:00 Maarten Lankhorst dev@lankhorst.se 2024-12-04T13:44:03+00:00 2b624a2c18656ea32e0849e7bc0018ba3c97ca64 cgroup resource allocation has to be handled in TTM, so -EAGAIN from cgroups can be converted into -ENOSPC, and the limitcg can be properly evicted in ttm code. When hitting a resource limit through -EAGAIN, the cgroup for which the limit is hit is also returned. This allows eviction to delete only from cgroups which are a subgroup of the current cgroup. The returned CSS is used to determine if eviction is valuable for a given resource, and allows TTM to only target specific resources to lower memory usage. Co-developed-by: Friedrich Vock <friedrich.vock@gmx.de> Signed-off-by: Friedrich Vock <friedrich.vock@gmx.de> Co-developed-by: Maxime Ripard <mripard@kernel.org> Signed-off-by: Maarten Lankhorst <dev@lankhorst.se> Acked-by: Tejun Heo <tj@kernel.org> Link: https://lore.kernel.org/r/20241204134410.1161769-4-dev@lankhorst.se Signed-off-by: Maxime Ripard <mripard@kernel.org> 
cgroup resource allocation has to be handled in TTM, so -EAGAIN from
cgroups can be converted into -ENOSPC, and the limitcg can be properly
evicted in ttm code.

When hitting a resource limit through -EAGAIN, the cgroup for which the
limit is hit is also returned. This allows eviction to delete only from
cgroups which are a subgroup of the current cgroup.

The returned CSS is used to determine if eviction is valuable for a
given resource, and allows TTM to only target specific resources to
lower memory usage.

Co-developed-by: Friedrich Vock <friedrich.vock@gmx.de>
Signed-off-by: Friedrich Vock <friedrich.vock@gmx.de>
Co-developed-by: Maxime Ripard <mripard@kernel.org>
Signed-off-by: Maarten Lankhorst <dev@lankhorst.se>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20241204134410.1161769-4-dev@lankhorst.se
Signed-off-by: Maxime Ripard <mripard@kernel.org>