[PATCH v5 00/17] Add generic memory shrinker to VirtIO-GPU and Panfrost DRM drivers

[PATCH v5 00/17] Add generic memory shrinker to VirtIO-GPU and Panfrost DRM drivers

[Dmitry Osipenko]

Hello,

This patchset introduces memory shrinker for the VirtIO-GPU DRM driver.
During OOM, the shrinker will release BOs that are marked as "not needed"
by userspace using the new madvise IOCTL, it will also evict idling BOs
to SWAP. The userspace in this case is the Mesa VirGL driver, it will mark
the cached BOs as "not needed", allowing kernel driver to release memory
of the cached shmem BOs on lowmem situations, preventing OOM kills.

This patchset adds memory purging and eviction support to VirtIO-GPU driver.

The Panfrost driver is switched to use generic memory shrinker. Eviction
support will come later on, after resolving the blocker bug in Panfrost.

This patchset also includes couple improvements and fixes for various
minor things that I found while was working on the shrinker.

The Mesa and IGT patches will be kept on hold until this kernel series
will be approved and merged.

This patchset was tested using Qemu and crosvm, including both cases of
IOMMU off/on.

Mesa: https://gitlab.freedesktop.org/digetx/mesa/-/commits/virgl-madvise
IGT:  https://gitlab.freedesktop.org/digetx/igt-gpu-tools/-/commits/virtio-madvise
      https://gitlab.freedesktop.org/digetx/igt-gpu-tools/-/commits/panfrost-madvise

Changelog:

v5: - Added new for-stable patch "drm/panfrost: Put mapping instead of
      shmem obj on panfrost_mmu_map_fault_addr() error" that corrects GEM's
      refcounting in case of error.

    - The drm_gem_shmem_v[un]map() now takes a separate vmap_lock for
      imported GEMs to avoid recursive locking of DMA reservations.
      This addresses v4 comment from Thomas Zimmermann about the potential
      deadlocking of vmapping.

    - Added ack from Thomas Zimmermann to "drm/shmem-helper: Correct
      doc-comment of drm_gem_shmem_get_sg_table()" patch.

    - Dropped explicit shmem states from the generic shrinker patch as
      was requested by Thomas Zimmermann.

    - Improved variable names and comments of the generic shrinker code.

    - Extended drm_gem_shmem_print_info() with the shrinker-state info in
      the "drm/virtio: Support memory shrinking" patch.

    - Moved evict()/swap_in()/purge() callbacks from drm_gem_object_funcs
      to drm_gem_shmem_object in the generic shrinker patch, for more
      consistency.

    - Corrected bisectability of the patches that was broken in v4
      by accident.

    - The virtio_gpu_plane_prepare_fb() now uses drm_gem_shmem_pin() instead
      of drm_gem_shmem_set_unpurgeable_and_unevictable() and does it only for
      shmem BOs in the "drm/virtio: Support memory shrinking" patch.

    - Made more functions private to drm_gem_shmem_helper.c as was requested
      by Thomas Zimmermann. This minimizes number of the public shmem helpers.

v4: - Corrected minor W=1 warnings reported by kernel test robot for v3.

    - Renamed DRM_GEM_SHMEM_PAGES_STATE_ACTIVE/INACTIVE to PINNED/UNPINNED,
      for more clarity.

v3: - Hardened shrinker's count() with usage of READ_ONCE() since we don't
      use atomic type for counting and technically compiler is free to
      re-fetch counter's variable.

    - "Correct drm_gem_shmem_get_sg_table() error handling" now uses
      PTR_ERR_OR_ZERO(), fixing typo that was made in v2.

    - Removed obsoleted shrinker from the Panfrost driver, which I missed to
      do in v2 by accident and Alyssa Rosenzweig managed to notice it.

    - CCed stable kernels in all patches that make fixes, even the minor ones,
      like was suggested by Emil Velikov and added his r-b to the patches.

    - Added t-b from Steven Price to the Panfrost's shrinker patch.

    - Corrected doc-comment of drm_gem_shmem_object.madv, like was suggested
      by Steven Price. Comment now says that madv=1 means "object is purged"
      instead of saying that value is unused.

    - Added more doc-comments to the new shmem shrinker API.

    - The "Improve DMA API usage for shmem BOs" patch got more improvements
      by removing the obsoleted drm_dev_set_unique() quirk and its comment.

    - Added patch that makes Virtio-GPU driver to use common dev_is_pci()
      helper, which was suggested by Robin Murphy.

    - Added new "drm/shmem-helper: Take GEM reservation lock instead of
      drm_gem_shmem locks" patch, which was suggested by Daniel Vetter.

    - Added new "drm/virtio: Simplify error handling of
      virtio_gpu_object_create()" patch.

    - Improved "Correct doc-comment of drm_gem_shmem_get_sg_table()" patch,
      like was suggested by Daniel Vetter, by saying that function returns
      ERR_PTR() and not errno.

    - virtio_gpu_purge_object() is fenced properly now, turned out
      virtio_gpu_notify() doesn't do fencing as I was supposing before.
      Stress testing of memory eviction revealed that.

    - Added new patch that corrects virtio_gpu_plane_cleanup_fb() to use
      appropriate atomic plane state.

    - SHMEM shrinker got eviction support.

    - VirtIO-GPU driver now supports memory eviction. It's enabled for a
      non-blob GEMs only, i.e. for VirGL. The blobs don't support dynamic
      attaching/detaching of guest's memory, so it's not trivial to enable
      them.

    - Added patch that removes obsoleted drm_gem_shmem_purge()

    - Added patch that makes drm_gem_shmem_get_pages() private.

    - Added patch that fixes lockup on dma_resv_reserve_fences() error.

v2: - Improved shrinker by using a more fine-grained locking to reduce
      contention during scan of objects and dropped locking from the
      'counting' callback by tracking count of shrinkable pages. This
      was suggested by Rob Clark in the comment to v1.

    - Factored out common shrinker code into drm_gem_shmem_helper.c
      and switched Panfrost driver to use the new common memory shrinker.
      This was proposed by Thomas Zimmermann in his prototype series that
      he shared with us in the comment to v1. Note that I only compile-tested
      the Panfrost driver.

    - Shrinker now takes object_name_lock during scan to prevent racing
      with dma-buf exporting.

    - Shrinker now takes vmap_lock during scan to prevent racing with shmem
      vmap/unmap code.

    - Added "Correct doc-comment of drm_gem_shmem_get_sg_table()" patch,
      which I sent out previously as a standalone change, since the
      drm_gem_shmem_helper.c is now touched by this patchset anyways and
      it doesn't hurt to group all the patches together.

Dmitry Osipenko (17):
  drm/panfrost: Put mapping instead of shmem obj on
    panfrost_mmu_map_fault_addr() error
  drm/virtio: Correct drm_gem_shmem_get_sg_table() error handling
  drm/virtio: Check whether transferred 2D BO is shmem
  drm/virtio: Unlock reservations on virtio_gpu_object_shmem_init()
    error
  drm/virtio: Unlock reservations on dma_resv_reserve_fences() error
  drm/virtio: Use appropriate atomic state in
    virtio_gpu_plane_cleanup_fb()
  drm/virtio: Simplify error handling of virtio_gpu_object_create()
  drm/virtio: Improve DMA API usage for shmem BOs
  drm/virtio: Use dev_is_pci()
  drm/shmem-helper: Correct doc-comment of drm_gem_shmem_get_sg_table()
  drm/shmem-helper: Take reservation lock instead of drm_gem_shmem locks
  drm/shmem-helper: Add generic memory shrinker
  drm/virtio: Support memory shrinking
  drm/panfrost: Switch to generic memory shrinker
  drm/shmem-helper: Make drm_gem_shmem_get_pages() private
  drm/shmem-helper: Make drm_gem_shmem_is_purgeable() private
  drm/shmem-helper: Remove drm_gem_shmem_purge_locked()

 drivers/gpu/drm/drm_gem_shmem_helper.c        | 800 ++++++++++++++++--
 drivers/gpu/drm/lima/lima_gem.c               |   8 +-
 drivers/gpu/drm/panfrost/Makefile             |   1 -
 drivers/gpu/drm/panfrost/panfrost_device.h    |   4 -
 drivers/gpu/drm/panfrost/panfrost_drv.c       |  19 +-
 drivers/gpu/drm/panfrost/panfrost_gem.c       |  28 +-
 drivers/gpu/drm/panfrost/panfrost_gem.h       |   9 -
 .../gpu/drm/panfrost/panfrost_gem_shrinker.c  | 122 ---
 drivers/gpu/drm/panfrost/panfrost_job.c       |  18 +-
 drivers/gpu/drm/panfrost/panfrost_mmu.c       |  17 +-
 drivers/gpu/drm/virtio/virtgpu_drv.c          |  53 +-
 drivers/gpu/drm/virtio/virtgpu_drv.h          |  20 +-
 drivers/gpu/drm/virtio/virtgpu_gem.c          |  50 +-
 drivers/gpu/drm/virtio/virtgpu_ioctl.c        |  37 +
 drivers/gpu/drm/virtio/virtgpu_kms.c          |  16 +-
 drivers/gpu/drm/virtio/virtgpu_object.c       | 195 +++--
 drivers/gpu/drm/virtio/virtgpu_plane.c        |  28 +-
 drivers/gpu/drm/virtio/virtgpu_vq.c           |  55 +-
 include/drm/drm_device.h                      |   4 +
 include/drm/drm_gem_shmem_helper.h            | 127 ++-
 include/uapi/drm/virtgpu_drm.h                |  14 +
 21 files changed, 1227 insertions(+), 398 deletions(-)
 delete mode 100644 drivers/gpu/drm/panfrost/panfrost_gem_shrinker.c

-- 
2.35.1

[PATCH v5 01/17] drm/panfrost: Put mapping instead of shmem obj on panfrost_mmu_map_fault_addr() error

[Dmitry Osipenko]

When panfrost_mmu_map_fault_addr() fails, the BO's mapping should be
unreferenced and not the shmem object that backs that mapping.

Cc: stable@vger.kernel.org
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
---
 drivers/gpu/drm/panfrost/panfrost_mmu.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/panfrost/panfrost_mmu.c b/drivers/gpu/drm/panfrost/panfrost_mmu.c
index d3f82b26a631..b285a8001b1d 100644
--- a/drivers/gpu/drm/panfrost/panfrost_mmu.c
+++ b/drivers/gpu/drm/panfrost/panfrost_mmu.c
@@ -518,7 +518,7 @@ static int panfrost_mmu_map_fault_addr(struct panfrost_device *pfdev, int as,
 err_pages:
 	drm_gem_shmem_put_pages(&bo->base);
 err_bo:
-	drm_gem_object_put(&bo->base.base);
+	panfrost_gem_mapping_put(bomapping);
 	return ret;
 }
 
-- 
2.35.1

[PATCH v5 02/17] drm/virtio: Correct drm_gem_shmem_get_sg_table() error handling

[Dmitry Osipenko]

drm_gem_shmem_get_sg_table() never ever returned NULL on error. Correct
the error handling to avoid crash on OOM.

Cc: stable@vger.kernel.org
Reviewed-by: Emil Velikov <emil.l.velikov@gmail.com>
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
---
 drivers/gpu/drm/virtio/virtgpu_object.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/virtio/virtgpu_object.c b/drivers/gpu/drm/virtio/virtgpu_object.c
index f293e6ad52da..3d0c8d4d1c20 100644
--- a/drivers/gpu/drm/virtio/virtgpu_object.c
+++ b/drivers/gpu/drm/virtio/virtgpu_object.c
@@ -168,9 +168,11 @@ static int virtio_gpu_object_shmem_init(struct virtio_gpu_device *vgdev,
 	 * since virtio_gpu doesn't support dma-buf import from other devices.
 	 */
 	shmem->pages = drm_gem_shmem_get_sg_table(&bo->base);
-	if (!shmem->pages) {
+	ret = PTR_ERR_OR_ZERO(shmem->pages);
+	if (ret) {
 		drm_gem_shmem_unpin(&bo->base);
-		return -EINVAL;
+		shmem->pages = NULL;
+		return ret;
 	}
 
 	if (use_dma_api) {
-- 
2.35.1

[PATCH v5 03/17] drm/virtio: Check whether transferred 2D BO is shmem

[Dmitry Osipenko]

Transferred 2D BO always must be a shmem BO. Add check for that to prevent
NULL dereference if userspace passes a VRAM BO.

Cc: stable@vger.kernel.org
Reviewed-by: Emil Velikov <emil.l.velikov@gmail.com>
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
---
 drivers/gpu/drm/virtio/virtgpu_vq.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/virtio/virtgpu_vq.c b/drivers/gpu/drm/virtio/virtgpu_vq.c
index 7c052efe8836..2edf31806b74 100644
--- a/drivers/gpu/drm/virtio/virtgpu_vq.c
+++ b/drivers/gpu/drm/virtio/virtgpu_vq.c
@@ -595,7 +595,7 @@ void virtio_gpu_cmd_transfer_to_host_2d(struct virtio_gpu_device *vgdev,
 	bool use_dma_api = !virtio_has_dma_quirk(vgdev->vdev);
 	struct virtio_gpu_object_shmem *shmem = to_virtio_gpu_shmem(bo);
 
-	if (use_dma_api)
+	if (virtio_gpu_is_shmem(bo) && use_dma_api)
 		dma_sync_sgtable_for_device(vgdev->vdev->dev.parent,
 					    shmem->pages, DMA_TO_DEVICE);
 
-- 
2.35.1

[PATCH v5 04/17] drm/virtio: Unlock reservations on virtio_gpu_object_shmem_init() error

[Dmitry Osipenko]

Unlock reservations in the error code path of virtio_gpu_object_create()
to silence debug warning splat produced by ww_mutex_destroy(&obj->lock)
when GEM is released with the held lock.

Cc: stable@vger.kernel.org
Reviewed-by: Emil Velikov <emil.l.velikov@gmail.com>
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
---
 drivers/gpu/drm/virtio/virtgpu_object.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/gpu/drm/virtio/virtgpu_object.c b/drivers/gpu/drm/virtio/virtgpu_object.c
index 3d0c8d4d1c20..21c19cdedce0 100644
--- a/drivers/gpu/drm/virtio/virtgpu_object.c
+++ b/drivers/gpu/drm/virtio/virtgpu_object.c
@@ -250,6 +250,8 @@ int virtio_gpu_object_create(struct virtio_gpu_device *vgdev,
 
 	ret = virtio_gpu_object_shmem_init(vgdev, bo, &ents, &nents);
 	if (ret != 0) {
+		if (fence)
+			virtio_gpu_array_unlock_resv(objs);
 		virtio_gpu_array_put_free(objs);
 		virtio_gpu_free_object(&shmem_obj->base);
 		return ret;
-- 
2.35.1

[PATCH v5 05/17] drm/virtio: Unlock reservations on dma_resv_reserve_fences() error

[Dmitry Osipenko]

Unlock reservations on dma_resv_reserve_fences() error to fix recursive
locking of the reservations when this error happens.

Cc: stable@vger.kernel.org
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
---
 drivers/gpu/drm/virtio/virtgpu_gem.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/virtio/virtgpu_gem.c b/drivers/gpu/drm/virtio/virtgpu_gem.c
index 580a78809836..7db48d17ee3a 100644
--- a/drivers/gpu/drm/virtio/virtgpu_gem.c
+++ b/drivers/gpu/drm/virtio/virtgpu_gem.c
@@ -228,8 +228,10 @@ int virtio_gpu_array_lock_resv(struct virtio_gpu_object_array *objs)
 
 	for (i = 0; i < objs->nents; ++i) {
 		ret = dma_resv_reserve_fences(objs->objs[i]->resv, 1);
-		if (ret)
+		if (ret) {
+			virtio_gpu_array_unlock_resv(objs);
 			return ret;
+		}
 	}
 	return ret;
 }
-- 
2.35.1

[PATCH v5 06/17] drm/virtio: Use appropriate atomic state in virtio_gpu_plane_cleanup_fb()

[Dmitry Osipenko]

Make virtio_gpu_plane_cleanup_fb() to clean the state which DRM core
wants to clean up and not the current plane's state. Normally the older
atomic state is cleaned up, but the newer state could also be cleaned up
in case of aborted commits.

Cc: stable@vger.kernel.org
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
---
 drivers/gpu/drm/virtio/virtgpu_plane.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/virtio/virtgpu_plane.c b/drivers/gpu/drm/virtio/virtgpu_plane.c
index 6d3cc9e238a4..7148f3813d8b 100644
--- a/drivers/gpu/drm/virtio/virtgpu_plane.c
+++ b/drivers/gpu/drm/virtio/virtgpu_plane.c
@@ -266,14 +266,14 @@ static int virtio_gpu_plane_prepare_fb(struct drm_plane *plane,
 }
 
 static void virtio_gpu_plane_cleanup_fb(struct drm_plane *plane,
-					struct drm_plane_state *old_state)
+					struct drm_plane_state *state)
 {
 	struct virtio_gpu_framebuffer *vgfb;
 
-	if (!plane->state->fb)
+	if (!state->fb)
 		return;
 
-	vgfb = to_virtio_gpu_framebuffer(plane->state->fb);
+	vgfb = to_virtio_gpu_framebuffer(state->fb);
 	if (vgfb->fence) {
 		dma_fence_put(&vgfb->fence->f);
 		vgfb->fence = NULL;
-- 
2.35.1

[PATCH v5 07/17] drm/virtio: Simplify error handling of virtio_gpu_object_create()

[Dmitry Osipenko]

Change the order of SHMEM initialization and reservation locking to
make code cleaner a tad and to prepare to transitioning of the common
GEM SHMEM code to use the GEM's reservation lock instead of the
shmem.page_lock.

There is no need to lock reservation during allocation of the SHMEM pages
because the lock is needed only to avoid racing with the async host-side
allocation. Hence we can safely move the SHMEM initialization out of the
reservation lock.

Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
---
 drivers/gpu/drm/virtio/virtgpu_object.c | 13 ++++---------
 1 file changed, 4 insertions(+), 9 deletions(-)

diff --git a/drivers/gpu/drm/virtio/virtgpu_object.c b/drivers/gpu/drm/virtio/virtgpu_object.c
index 21c19cdedce0..18f70ef6b4d0 100644
--- a/drivers/gpu/drm/virtio/virtgpu_object.c
+++ b/drivers/gpu/drm/virtio/virtgpu_object.c
@@ -236,6 +236,10 @@ int virtio_gpu_object_create(struct virtio_gpu_device *vgdev,
 
 	bo->dumb = params->dumb;
 
+	ret = virtio_gpu_object_shmem_init(vgdev, bo, &ents, &nents);
+	if (ret != 0)
+		goto err_put_id;
+
 	if (fence) {
 		ret = -ENOMEM;
 		objs = virtio_gpu_array_alloc(1);
@@ -248,15 +252,6 @@ int virtio_gpu_object_create(struct virtio_gpu_device *vgdev,
 			goto err_put_objs;
 	}
 
-	ret = virtio_gpu_object_shmem_init(vgdev, bo, &ents, &nents);
-	if (ret != 0) {
-		if (fence)
-			virtio_gpu_array_unlock_resv(objs);
-		virtio_gpu_array_put_free(objs);
-		virtio_gpu_free_object(&shmem_obj->base);
-		return ret;
-	}
-
 	if (params->blob) {
 		if (params->blob_mem == VIRTGPU_BLOB_MEM_GUEST)
 			bo->guest_blob = true;
-- 
2.35.1

[PATCH v5 08/17] drm/virtio: Improve DMA API usage for shmem BOs

[Dmitry Osipenko]

DRM API requires the DRM's driver to be backed with the device that can
be used for generic DMA operations. The VirtIO-GPU device can't perform
DMA operations if it uses PCI transport because PCI device driver creates
a virtual VirtIO-GPU device that isn't associated with the PCI. Use PCI's
GPU device for the DRM's device instead of the VirtIO-GPU device and drop
DMA-related hacks from the VirtIO-GPU driver.

Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
---
 drivers/gpu/drm/virtio/virtgpu_drv.c    | 51 ++++++----------------
 drivers/gpu/drm/virtio/virtgpu_drv.h    |  5 +--
 drivers/gpu/drm/virtio/virtgpu_kms.c    |  7 ++--
 drivers/gpu/drm/virtio/virtgpu_object.c | 56 +++++--------------------
 drivers/gpu/drm/virtio/virtgpu_vq.c     | 13 +++---
 5 files changed, 32 insertions(+), 100 deletions(-)

diff --git a/drivers/gpu/drm/virtio/virtgpu_drv.c b/drivers/gpu/drm/virtio/virtgpu_drv.c
index 5f25a8d15464..0141b7df97ec 100644
--- a/drivers/gpu/drm/virtio/virtgpu_drv.c
+++ b/drivers/gpu/drm/virtio/virtgpu_drv.c
@@ -46,12 +46,11 @@ static int virtio_gpu_modeset = -1;
 MODULE_PARM_DESC(modeset, "Disable/Enable modesetting");
 module_param_named(modeset, virtio_gpu_modeset, int, 0400);
 
-static int virtio_gpu_pci_quirk(struct drm_device *dev, struct virtio_device *vdev)
+static int virtio_gpu_pci_quirk(struct drm_device *dev)
 {
-	struct pci_dev *pdev = to_pci_dev(vdev->dev.parent);
+	struct pci_dev *pdev = to_pci_dev(dev->dev);
 	const char *pname = dev_name(&pdev->dev);
 	bool vga = (pdev->class >> 8) == PCI_CLASS_DISPLAY_VGA;
-	char unique[20];
 	int ret;
 
 	DRM_INFO("pci: %s detected at %s\n",
@@ -63,39 +62,7 @@ static int virtio_gpu_pci_quirk(struct drm_device *dev, struct virtio_device *vd
 			return ret;
 	}
 
-	/*
-	 * Normally the drm_dev_set_unique() call is done by core DRM.
-	 * The following comment covers, why virtio cannot rely on it.
-	 *
-	 * Unlike the other virtual GPU drivers, virtio abstracts the
-	 * underlying bus type by using struct virtio_device.
-	 *
-	 * Hence the dev_is_pci() check, used in core DRM, will fail
-	 * and the unique returned will be the virtio_device "virtio0",
-	 * while a "pci:..." one is required.
-	 *
-	 * A few other ideas were considered:
-	 * - Extend the dev_is_pci() check [in drm_set_busid] to
-	 *   consider virtio.
-	 *   Seems like a bigger hack than what we have already.
-	 *
-	 * - Point drm_device::dev to the parent of the virtio_device
-	 *   Semantic changes:
-	 *   * Using the wrong device for i2c, framebuffer_alloc and
-	 *     prime import.
-	 *   Visual changes:
-	 *   * Helpers such as DRM_DEV_ERROR, dev_info, drm_printer,
-	 *     will print the wrong information.
-	 *
-	 * We could address the latter issues, by introducing
-	 * drm_device::bus_dev, ... which would be used solely for this.
-	 *
-	 * So for the moment keep things as-is, with a bulky comment
-	 * for the next person who feels like removing this
-	 * drm_dev_set_unique() quirk.
-	 */
-	snprintf(unique, sizeof(unique), "pci:%s", pname);
-	return drm_dev_set_unique(dev, unique);
+	return 0;
 }
 
 static int virtio_gpu_probe(struct virtio_device *vdev)
@@ -109,18 +76,24 @@ static int virtio_gpu_probe(struct virtio_device *vdev)
 	if (virtio_gpu_modeset == 0)
 		return -EINVAL;
 
-	dev = drm_dev_alloc(&driver, &vdev->dev);
+	/*
+	 * The virtio-gpu device is a virtual device that doesn't have DMA
+	 * ops assigned to it, nor DMA mask set and etc. Its parent device
+	 * is actual GPU device we want to use it for the DRM's device in
+	 * order to benefit from using generic DRM APIs.
+	 */
+	dev = drm_dev_alloc(&driver, vdev->dev.parent);
 	if (IS_ERR(dev))
 		return PTR_ERR(dev);
 	vdev->priv = dev;
 
 	if (!strcmp(vdev->dev.parent->bus->name, "pci")) {
-		ret = virtio_gpu_pci_quirk(dev, vdev);
+		ret = virtio_gpu_pci_quirk(dev);
 		if (ret)
 			goto err_free;
 	}
 
-	ret = virtio_gpu_init(dev);
+	ret = virtio_gpu_init(vdev, dev);
 	if (ret)
 		goto err_free;
 
diff --git a/drivers/gpu/drm/virtio/virtgpu_drv.h b/drivers/gpu/drm/virtio/virtgpu_drv.h
index 0a194aaad419..b2d93cb12ebf 100644
--- a/drivers/gpu/drm/virtio/virtgpu_drv.h
+++ b/drivers/gpu/drm/virtio/virtgpu_drv.h
@@ -100,8 +100,6 @@ struct virtio_gpu_object {
 
 struct virtio_gpu_object_shmem {
 	struct virtio_gpu_object base;
-	struct sg_table *pages;
-	uint32_t mapped;
 };
 
 struct virtio_gpu_object_vram {
@@ -214,7 +212,6 @@ struct virtio_gpu_drv_cap_cache {
 };
 
 struct virtio_gpu_device {
-	struct device *dev;
 	struct drm_device *ddev;
 
 	struct virtio_device *vdev;
@@ -282,7 +279,7 @@ extern struct drm_ioctl_desc virtio_gpu_ioctls[DRM_VIRTIO_NUM_IOCTLS];
 void virtio_gpu_create_context(struct drm_device *dev, struct drm_file *file);
 
 /* virtgpu_kms.c */
-int virtio_gpu_init(struct drm_device *dev);
+int virtio_gpu_init(struct virtio_device *vdev, struct drm_device *dev);
 void virtio_gpu_deinit(struct drm_device *dev);
 void virtio_gpu_release(struct drm_device *dev);
 int virtio_gpu_driver_open(struct drm_device *dev, struct drm_file *file);
diff --git a/drivers/gpu/drm/virtio/virtgpu_kms.c b/drivers/gpu/drm/virtio/virtgpu_kms.c
index 3313b92db531..0d1e3eb61bee 100644
--- a/drivers/gpu/drm/virtio/virtgpu_kms.c
+++ b/drivers/gpu/drm/virtio/virtgpu_kms.c
@@ -110,7 +110,7 @@ static void virtio_gpu_get_capsets(struct virtio_gpu_device *vgdev,
 	vgdev->num_capsets = num_capsets;
 }
 
-int virtio_gpu_init(struct drm_device *dev)
+int virtio_gpu_init(struct virtio_device *vdev, struct drm_device *dev)
 {
 	static vq_callback_t *callbacks[] = {
 		virtio_gpu_ctrl_ack, virtio_gpu_cursor_ack
@@ -123,7 +123,7 @@ int virtio_gpu_init(struct drm_device *dev)
 	u32 num_scanouts, num_capsets;
 	int ret = 0;
 
-	if (!virtio_has_feature(dev_to_virtio(dev->dev), VIRTIO_F_VERSION_1))
+	if (!virtio_has_feature(vdev, VIRTIO_F_VERSION_1))
 		return -ENODEV;
 
 	vgdev = kzalloc(sizeof(struct virtio_gpu_device), GFP_KERNEL);
@@ -132,8 +132,7 @@ int virtio_gpu_init(struct drm_device *dev)
 
 	vgdev->ddev = dev;
 	dev->dev_private = vgdev;
-	vgdev->vdev = dev_to_virtio(dev->dev);
-	vgdev->dev = dev->dev;
+	vgdev->vdev = vdev;
 
 	spin_lock_init(&vgdev->display_info_lock);
 	spin_lock_init(&vgdev->resource_export_lock);
diff --git a/drivers/gpu/drm/virtio/virtgpu_object.c b/drivers/gpu/drm/virtio/virtgpu_object.c
index 18f70ef6b4d0..8d7728181de0 100644
--- a/drivers/gpu/drm/virtio/virtgpu_object.c
+++ b/drivers/gpu/drm/virtio/virtgpu_object.c
@@ -67,21 +67,6 @@ void virtio_gpu_cleanup_object(struct virtio_gpu_object *bo)
 
 	virtio_gpu_resource_id_put(vgdev, bo->hw_res_handle);
 	if (virtio_gpu_is_shmem(bo)) {
-		struct virtio_gpu_object_shmem *shmem = to_virtio_gpu_shmem(bo);
-
-		if (shmem->pages) {
-			if (shmem->mapped) {
-				dma_unmap_sgtable(vgdev->vdev->dev.parent,
-					     shmem->pages, DMA_TO_DEVICE, 0);
-				shmem->mapped = 0;
-			}
-
-			sg_free_table(shmem->pages);
-			kfree(shmem->pages);
-			shmem->pages = NULL;
-			drm_gem_shmem_unpin(&bo->base);
-		}
-
 		drm_gem_shmem_free(&bo->base);
 	} else if (virtio_gpu_is_vram(bo)) {
 		struct virtio_gpu_object_vram *vram = to_virtio_gpu_vram(bo);
@@ -153,37 +138,18 @@ static int virtio_gpu_object_shmem_init(struct virtio_gpu_device *vgdev,
 					unsigned int *nents)
 {
 	bool use_dma_api = !virtio_has_dma_quirk(vgdev->vdev);
-	struct virtio_gpu_object_shmem *shmem = to_virtio_gpu_shmem(bo);
 	struct scatterlist *sg;
-	int si, ret;
+	struct sg_table *pages;
+	int si;
 
-	ret = drm_gem_shmem_pin(&bo->base);
-	if (ret < 0)
-		return -EINVAL;
-
-	/*
-	 * virtio_gpu uses drm_gem_shmem_get_sg_table instead of
-	 * drm_gem_shmem_get_pages_sgt because virtio has it's own set of
-	 * dma-ops. This is discouraged for other drivers, but should be fine
-	 * since virtio_gpu doesn't support dma-buf import from other devices.
-	 */
-	shmem->pages = drm_gem_shmem_get_sg_table(&bo->base);
-	ret = PTR_ERR_OR_ZERO(shmem->pages);
-	if (ret) {
-		drm_gem_shmem_unpin(&bo->base);
-		shmem->pages = NULL;
-		return ret;
-	}
+	pages = drm_gem_shmem_get_pages_sgt(&bo->base);
+	if (IS_ERR(pages))
+		return PTR_ERR(pages);
 
-	if (use_dma_api) {
-		ret = dma_map_sgtable(vgdev->vdev->dev.parent,
-				      shmem->pages, DMA_TO_DEVICE, 0);
-		if (ret)
-			return ret;
-		*nents = shmem->mapped = shmem->pages->nents;
-	} else {
-		*nents = shmem->pages->orig_nents;
-	}
+	if (use_dma_api)
+		*nents = pages->nents;
+	else
+		*nents = pages->orig_nents;
 
 	*ents = kvmalloc_array(*nents,
 			       sizeof(struct virtio_gpu_mem_entry),
@@ -194,13 +160,13 @@ static int virtio_gpu_object_shmem_init(struct virtio_gpu_device *vgdev,
 	}
 
 	if (use_dma_api) {
-		for_each_sgtable_dma_sg(shmem->pages, sg, si) {
+		for_each_sgtable_dma_sg(pages, sg, si) {
 			(*ents)[si].addr = cpu_to_le64(sg_dma_address(sg));
 			(*ents)[si].length = cpu_to_le32(sg_dma_len(sg));
 			(*ents)[si].padding = 0;
 		}
 	} else {
-		for_each_sgtable_sg(shmem->pages, sg, si) {
+		for_each_sgtable_sg(pages, sg, si) {
 			(*ents)[si].addr = cpu_to_le64(sg_phys(sg));
 			(*ents)[si].length = cpu_to_le32(sg->length);
 			(*ents)[si].padding = 0;
diff --git a/drivers/gpu/drm/virtio/virtgpu_vq.c b/drivers/gpu/drm/virtio/virtgpu_vq.c
index 2edf31806b74..06566e44307d 100644
--- a/drivers/gpu/drm/virtio/virtgpu_vq.c
+++ b/drivers/gpu/drm/virtio/virtgpu_vq.c
@@ -593,11 +593,10 @@ void virtio_gpu_cmd_transfer_to_host_2d(struct virtio_gpu_device *vgdev,
 	struct virtio_gpu_transfer_to_host_2d *cmd_p;
 	struct virtio_gpu_vbuffer *vbuf;
 	bool use_dma_api = !virtio_has_dma_quirk(vgdev->vdev);
-	struct virtio_gpu_object_shmem *shmem = to_virtio_gpu_shmem(bo);
 
 	if (virtio_gpu_is_shmem(bo) && use_dma_api)
-		dma_sync_sgtable_for_device(vgdev->vdev->dev.parent,
-					    shmem->pages, DMA_TO_DEVICE);
+		dma_sync_sgtable_for_device(&vgdev->vdev->dev,
+					    bo->base.sgt, DMA_TO_DEVICE);
 
 	cmd_p = virtio_gpu_alloc_cmd(vgdev, &vbuf, sizeof(*cmd_p));
 	memset(cmd_p, 0, sizeof(*cmd_p));
@@ -1017,11 +1016,9 @@ void virtio_gpu_cmd_transfer_to_host_3d(struct virtio_gpu_device *vgdev,
 	struct virtio_gpu_vbuffer *vbuf;
 	bool use_dma_api = !virtio_has_dma_quirk(vgdev->vdev);
 
-	if (virtio_gpu_is_shmem(bo) && use_dma_api) {
-		struct virtio_gpu_object_shmem *shmem = to_virtio_gpu_shmem(bo);
-		dma_sync_sgtable_for_device(vgdev->vdev->dev.parent,
-					    shmem->pages, DMA_TO_DEVICE);
-	}
+	if (virtio_gpu_is_shmem(bo) && use_dma_api)
+		dma_sync_sgtable_for_device(&vgdev->vdev->dev,
+					    bo->base.sgt, DMA_TO_DEVICE);
 
 	cmd_p = virtio_gpu_alloc_cmd(vgdev, &vbuf, sizeof(*cmd_p));
 	memset(cmd_p, 0, sizeof(*cmd_p));
-- 
2.35.1

[PATCH v5 09/17] drm/virtio: Use dev_is_pci()

[Dmitry Osipenko]

Use common dev_is_pci() helper to replace the strcmp("pci") used by driver.

Suggested-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
---
 drivers/gpu/drm/virtio/virtgpu_drv.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/virtio/virtgpu_drv.c b/drivers/gpu/drm/virtio/virtgpu_drv.c
index 0141b7df97ec..0035affc3e59 100644
--- a/drivers/gpu/drm/virtio/virtgpu_drv.c
+++ b/drivers/gpu/drm/virtio/virtgpu_drv.c
@@ -87,7 +87,7 @@ static int virtio_gpu_probe(struct virtio_device *vdev)
 		return PTR_ERR(dev);
 	vdev->priv = dev;
 
-	if (!strcmp(vdev->dev.parent->bus->name, "pci")) {
+	if (dev_is_pci(vdev->dev.parent)) {
 		ret = virtio_gpu_pci_quirk(dev);
 		if (ret)
 			goto err_free;
-- 
2.35.1

[PATCH v5 10/17] drm/shmem-helper: Correct doc-comment of drm_gem_shmem_get_sg_table()

[Dmitry Osipenko]

drm_gem_shmem_get_sg_table() never returns NULL on error, but a ERR_PTR.
Correct the doc comment which says that it returns NULL on error.

Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
---
 drivers/gpu/drm/drm_gem_shmem_helper.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c
index 8ad0e02991ca..5c7a7106b41d 100644
--- a/drivers/gpu/drm/drm_gem_shmem_helper.c
+++ b/drivers/gpu/drm/drm_gem_shmem_helper.c
@@ -662,7 +662,8 @@ EXPORT_SYMBOL(drm_gem_shmem_print_info);
  * drm_gem_shmem_get_pages_sgt() instead.
  *
  * Returns:
- * A pointer to the scatter/gather table of pinned pages or NULL on failure.
+ * A pointer to the scatter/gather table of pinned pages or an ERR_PTR()-encoded
+ * error code on failure.
  */
 struct sg_table *drm_gem_shmem_get_sg_table(struct drm_gem_shmem_object *shmem)
 {
@@ -688,7 +689,8 @@ EXPORT_SYMBOL_GPL(drm_gem_shmem_get_sg_table);
  * drm_gem_shmem_get_sg_table() should not be directly called by drivers.
  *
  * Returns:
- * A pointer to the scatter/gather table of pinned pages or errno on failure.
+ * A pointer to the scatter/gather table of pinned pages or an ERR_PTR()-encoded
+ * error code on failure.
  */
 struct sg_table *drm_gem_shmem_get_pages_sgt(struct drm_gem_shmem_object *shmem)
 {
-- 
2.35.1

[PATCH v5 11/17] drm/shmem-helper: Take reservation lock instead of drm_gem_shmem locks

[Dmitry Osipenko]

Replace drm_gem_shmem locks with the reservation lock to make GEM
lockings more consistent.

Previously drm_gem_shmem_vmap() and drm_gem_shmem_get_pages() were
protected by separate locks, now it's the same lock for non-imported GEMs.
For imported GEMs with still use a separate lock in vmap/vunmap() to
avoid recursive locking of reservations, the reservation's locking isn't
needed in this case.

Suggested-by: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
---
 drivers/gpu/drm/drm_gem_shmem_helper.c        | 54 ++++++++++++-------
 drivers/gpu/drm/lima/lima_gem.c               |  8 +--
 .../gpu/drm/panfrost/panfrost_gem_shrinker.c  |  4 +-
 drivers/gpu/drm/panfrost/panfrost_mmu.c       | 15 +++---
 include/drm/drm_gem_shmem_helper.h            |  5 --
 5 files changed, 50 insertions(+), 36 deletions(-)

diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c
index 5c7a7106b41d..cc90a4c28ace 100644
--- a/drivers/gpu/drm/drm_gem_shmem_helper.c
+++ b/drivers/gpu/drm/drm_gem_shmem_helper.c
@@ -86,7 +86,6 @@ __drm_gem_shmem_create(struct drm_device *dev, size_t size, bool private)
 	if (ret)
 		goto err_release;
 
-	mutex_init(&shmem->pages_lock);
 	mutex_init(&shmem->vmap_lock);
 	INIT_LIST_HEAD(&shmem->madv_list);
 
@@ -157,8 +156,6 @@ void drm_gem_shmem_free(struct drm_gem_shmem_object *shmem)
 	WARN_ON(shmem->pages_use_count);
 
 	drm_gem_object_release(obj);
-	mutex_destroy(&shmem->pages_lock);
-	mutex_destroy(&shmem->vmap_lock);
 	kfree(shmem);
 }
 EXPORT_SYMBOL_GPL(drm_gem_shmem_free);
@@ -209,11 +206,11 @@ int drm_gem_shmem_get_pages(struct drm_gem_shmem_object *shmem)
 
 	WARN_ON(shmem->base.import_attach);
 
-	ret = mutex_lock_interruptible(&shmem->pages_lock);
+	ret = dma_resv_lock_interruptible(shmem->base.resv, NULL);
 	if (ret)
 		return ret;
 	ret = drm_gem_shmem_get_pages_locked(shmem);
-	mutex_unlock(&shmem->pages_lock);
+	dma_resv_unlock(shmem->base.resv);
 
 	return ret;
 }
@@ -248,9 +245,9 @@ static void drm_gem_shmem_put_pages_locked(struct drm_gem_shmem_object *shmem)
  */
 void drm_gem_shmem_put_pages(struct drm_gem_shmem_object *shmem)
 {
-	mutex_lock(&shmem->pages_lock);
+	dma_resv_lock(shmem->base.resv, NULL);
 	drm_gem_shmem_put_pages_locked(shmem);
-	mutex_unlock(&shmem->pages_lock);
+	dma_resv_unlock(shmem->base.resv);
 }
 EXPORT_SYMBOL(drm_gem_shmem_put_pages);
 
@@ -310,7 +307,7 @@ static int drm_gem_shmem_vmap_locked(struct drm_gem_shmem_object *shmem,
 	} else {
 		pgprot_t prot = PAGE_KERNEL;
 
-		ret = drm_gem_shmem_get_pages(shmem);
+		ret = drm_gem_shmem_get_pages_locked(shmem);
 		if (ret)
 			goto err_zero_use;
 
@@ -358,13 +355,22 @@ static int drm_gem_shmem_vmap_locked(struct drm_gem_shmem_object *shmem,
 int drm_gem_shmem_vmap(struct drm_gem_shmem_object *shmem,
 		       struct iosys_map *map)
 {
+	struct drm_gem_object *obj = &shmem->base;
 	int ret;
 
-	ret = mutex_lock_interruptible(&shmem->vmap_lock);
+	if (obj->import_attach)
+		ret = mutex_lock_interruptible(&shmem->vmap_lock);
+	else
+		ret = dma_resv_lock_interruptible(shmem->base.resv, NULL);
+
 	if (ret)
 		return ret;
 	ret = drm_gem_shmem_vmap_locked(shmem, map);
-	mutex_unlock(&shmem->vmap_lock);
+
+	if (obj->import_attach)
+		mutex_unlock(&shmem->vmap_lock);
+	else
+		dma_resv_unlock(shmem->base.resv);
 
 	return ret;
 }
@@ -385,7 +391,7 @@ static void drm_gem_shmem_vunmap_locked(struct drm_gem_shmem_object *shmem,
 		dma_buf_vunmap(obj->import_attach->dmabuf, map);
 	} else {
 		vunmap(shmem->vaddr);
-		drm_gem_shmem_put_pages(shmem);
+		drm_gem_shmem_put_pages_locked(shmem);
 	}
 
 	shmem->vaddr = NULL;
@@ -406,9 +412,19 @@ static void drm_gem_shmem_vunmap_locked(struct drm_gem_shmem_object *shmem,
 void drm_gem_shmem_vunmap(struct drm_gem_shmem_object *shmem,
 			  struct iosys_map *map)
 {
-	mutex_lock(&shmem->vmap_lock);
+	struct drm_gem_object *obj = &shmem->base;
+
+	if (obj->import_attach)
+		mutex_lock(&shmem->vmap_lock);
+	else
+		dma_resv_lock(shmem->base.resv, NULL);
+
 	drm_gem_shmem_vunmap_locked(shmem, map);
-	mutex_unlock(&shmem->vmap_lock);
+
+	if (obj->import_attach)
+		mutex_unlock(&shmem->vmap_lock);
+	else
+		dma_resv_unlock(shmem->base.resv);
 }
 EXPORT_SYMBOL(drm_gem_shmem_vunmap);
 
@@ -442,14 +458,14 @@ drm_gem_shmem_create_with_handle(struct drm_file *file_priv,
  */
 int drm_gem_shmem_madvise(struct drm_gem_shmem_object *shmem, int madv)
 {
-	mutex_lock(&shmem->pages_lock);
+	dma_resv_lock(shmem->base.resv, NULL);
 
 	if (shmem->madv >= 0)
 		shmem->madv = madv;
 
 	madv = shmem->madv;
 
-	mutex_unlock(&shmem->pages_lock);
+	dma_resv_unlock(shmem->base.resv);
 
 	return (madv >= 0);
 }
@@ -487,10 +503,10 @@ EXPORT_SYMBOL(drm_gem_shmem_purge_locked);
 
 bool drm_gem_shmem_purge(struct drm_gem_shmem_object *shmem)
 {
-	if (!mutex_trylock(&shmem->pages_lock))
+	if (!dma_resv_trylock(shmem->base.resv))
 		return false;
 	drm_gem_shmem_purge_locked(shmem);
-	mutex_unlock(&shmem->pages_lock);
+	dma_resv_unlock(shmem->base.resv);
 
 	return true;
 }
@@ -549,7 +565,7 @@ static vm_fault_t drm_gem_shmem_fault(struct vm_fault *vmf)
 	/* We don't use vmf->pgoff since that has the fake offset */
 	page_offset = (vmf->address - vma->vm_start) >> PAGE_SHIFT;
 
-	mutex_lock(&shmem->pages_lock);
+	dma_resv_lock(shmem->base.resv, NULL);
 
 	if (page_offset >= num_pages ||
 	    WARN_ON_ONCE(!shmem->pages) ||
@@ -561,7 +577,7 @@ static vm_fault_t drm_gem_shmem_fault(struct vm_fault *vmf)
 		ret = vmf_insert_pfn(vma, vmf->address, page_to_pfn(page));
 	}
 
-	mutex_unlock(&shmem->pages_lock);
+	dma_resv_unlock(shmem->base.resv);
 
 	return ret;
 }
diff --git a/drivers/gpu/drm/lima/lima_gem.c b/drivers/gpu/drm/lima/lima_gem.c
index 0f1ca0b0db49..5008f0c2428f 100644
--- a/drivers/gpu/drm/lima/lima_gem.c
+++ b/drivers/gpu/drm/lima/lima_gem.c
@@ -34,7 +34,7 @@ int lima_heap_alloc(struct lima_bo *bo, struct lima_vm *vm)
 
 	new_size = min(new_size, bo->base.base.size);
 
-	mutex_lock(&bo->base.pages_lock);
+	dma_resv_lock(bo->base.base.resv, NULL);
 
 	if (bo->base.pages) {
 		pages = bo->base.pages;
@@ -42,7 +42,7 @@ int lima_heap_alloc(struct lima_bo *bo, struct lima_vm *vm)
 		pages = kvmalloc_array(bo->base.base.size >> PAGE_SHIFT,
 				       sizeof(*pages), GFP_KERNEL | __GFP_ZERO);
 		if (!pages) {
-			mutex_unlock(&bo->base.pages_lock);
+			dma_resv_unlock(bo->base.base.resv);
 			return -ENOMEM;
 		}
 
@@ -56,13 +56,13 @@ int lima_heap_alloc(struct lima_bo *bo, struct lima_vm *vm)
 		struct page *page = shmem_read_mapping_page(mapping, i);
 
 		if (IS_ERR(page)) {
-			mutex_unlock(&bo->base.pages_lock);
+			dma_resv_unlock(bo->base.base.resv);
 			return PTR_ERR(page);
 		}
 		pages[i] = page;
 	}
 
-	mutex_unlock(&bo->base.pages_lock);
+	dma_resv_unlock(bo->base.base.resv);
 
 	ret = sg_alloc_table_from_pages(&sgt, pages, i, 0,
 					new_size, GFP_KERNEL);
diff --git a/drivers/gpu/drm/panfrost/panfrost_gem_shrinker.c b/drivers/gpu/drm/panfrost/panfrost_gem_shrinker.c
index 77e7cb6d1ae3..3bcf8c291866 100644
--- a/drivers/gpu/drm/panfrost/panfrost_gem_shrinker.c
+++ b/drivers/gpu/drm/panfrost/panfrost_gem_shrinker.c
@@ -48,14 +48,14 @@ static bool panfrost_gem_purge(struct drm_gem_object *obj)
 	if (!mutex_trylock(&bo->mappings.lock))
 		return false;
 
-	if (!mutex_trylock(&shmem->pages_lock))
+	if (!dma_resv_trylock(shmem->base.resv))
 		goto unlock_mappings;
 
 	panfrost_gem_teardown_mappings_locked(bo);
 	drm_gem_shmem_purge_locked(&bo->base);
 	ret = true;
 
-	mutex_unlock(&shmem->pages_lock);
+	dma_resv_unlock(shmem->base.resv);
 
 unlock_mappings:
 	mutex_unlock(&bo->mappings.lock);
diff --git a/drivers/gpu/drm/panfrost/panfrost_mmu.c b/drivers/gpu/drm/panfrost/panfrost_mmu.c
index b285a8001b1d..9b261a1c7f5c 100644
--- a/drivers/gpu/drm/panfrost/panfrost_mmu.c
+++ b/drivers/gpu/drm/panfrost/panfrost_mmu.c
@@ -424,6 +424,7 @@ static int panfrost_mmu_map_fault_addr(struct panfrost_device *pfdev, int as,
 	struct panfrost_gem_mapping *bomapping;
 	struct panfrost_gem_object *bo;
 	struct address_space *mapping;
+	struct drm_gem_object *obj;
 	pgoff_t page_offset;
 	struct sg_table *sgt;
 	struct page **pages;
@@ -446,13 +447,15 @@ static int panfrost_mmu_map_fault_addr(struct panfrost_device *pfdev, int as,
 	page_offset = addr >> PAGE_SHIFT;
 	page_offset -= bomapping->mmnode.start;
 
-	mutex_lock(&bo->base.pages_lock);
+	obj = &bo->base.base;
+
+	dma_resv_lock(obj->resv, NULL);
 
 	if (!bo->base.pages) {
 		bo->sgts = kvmalloc_array(bo->base.base.size / SZ_2M,
 				     sizeof(struct sg_table), GFP_KERNEL | __GFP_ZERO);
 		if (!bo->sgts) {
-			mutex_unlock(&bo->base.pages_lock);
+			dma_resv_unlock(obj->resv);
 			ret = -ENOMEM;
 			goto err_bo;
 		}
@@ -462,7 +465,7 @@ static int panfrost_mmu_map_fault_addr(struct panfrost_device *pfdev, int as,
 		if (!pages) {
 			kvfree(bo->sgts);
 			bo->sgts = NULL;
-			mutex_unlock(&bo->base.pages_lock);
+			dma_resv_unlock(obj->resv);
 			ret = -ENOMEM;
 			goto err_bo;
 		}
@@ -472,7 +475,7 @@ static int panfrost_mmu_map_fault_addr(struct panfrost_device *pfdev, int as,
 		pages = bo->base.pages;
 		if (pages[page_offset]) {
 			/* Pages are already mapped, bail out. */
-			mutex_unlock(&bo->base.pages_lock);
+			dma_resv_unlock(obj->resv);
 			goto out;
 		}
 	}
@@ -483,13 +486,13 @@ static int panfrost_mmu_map_fault_addr(struct panfrost_device *pfdev, int as,
 	for (i = page_offset; i < page_offset + NUM_FAULT_PAGES; i++) {
 		pages[i] = shmem_read_mapping_page(mapping, i);
 		if (IS_ERR(pages[i])) {
-			mutex_unlock(&bo->base.pages_lock);
+			dma_resv_unlock(obj->resv);
 			ret = PTR_ERR(pages[i]);
 			goto err_pages;
 		}
 	}
 
-	mutex_unlock(&bo->base.pages_lock);
+	dma_resv_unlock(obj->resv);
 
 	sgt = &bo->sgts[page_offset / (SZ_2M / PAGE_SIZE)];
 	ret = sg_alloc_table_from_pages(sgt, pages + page_offset,
diff --git a/include/drm/drm_gem_shmem_helper.h b/include/drm/drm_gem_shmem_helper.h
index d0a57853c188..6f2b8fee620c 100644
--- a/include/drm/drm_gem_shmem_helper.h
+++ b/include/drm/drm_gem_shmem_helper.h
@@ -26,11 +26,6 @@ struct drm_gem_shmem_object {
 	 */
 	struct drm_gem_object base;
 
-	/**
-	 * @pages_lock: Protects the page table and use count
-	 */
-	struct mutex pages_lock;
-
 	/**
 	 * @pages: Page table
 	 */
-- 
2.35.1

[PATCH v5 12/17] drm/shmem-helper: Add generic memory shrinker

[Dmitry Osipenko]

Introduce a common DRM SHMEM shrinker. It allows to reduce code
duplication among DRM drivers that implement theirs own shrinkers.
This is initial version of the shrinker that covers basic needs of
GPU drivers, both purging and eviction of shmem objects are supported.

This patch is based on a couple ideas borrowed from Rob's Clark MSM
shrinker and Thomas' Zimmermann variant of SHMEM shrinker.

In order to start using DRM SHMEM shrinker drivers should:

1. Optionally implement new purge(), evict() + swap_in() shmem objects
   callbacks.
2. Register shrinker using drm_gem_shmem_shrinker_register(drm_device).
3. Use drm_gem_shmem_set_purgeable_and_evictable(shmem) and alike API
   functions to activate shrinking of shmem GEMs.

Signed-off-by: Daniel Almeida <daniel.almeida@collabora.com>
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
---
 drivers/gpu/drm/drm_gem_shmem_helper.c | 734 +++++++++++++++++++++++--
 include/drm/drm_device.h               |   4 +
 include/drm/drm_gem_shmem_helper.h     | 115 +++-
 3 files changed, 820 insertions(+), 33 deletions(-)

diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c
index cc90a4c28ace..25e9bc2803ee 100644
--- a/drivers/gpu/drm/drm_gem_shmem_helper.c
+++ b/drivers/gpu/drm/drm_gem_shmem_helper.c
@@ -89,6 +89,13 @@ __drm_gem_shmem_create(struct drm_device *dev, size_t size, bool private)
 	mutex_init(&shmem->vmap_lock);
 	INIT_LIST_HEAD(&shmem->madv_list);
 
+	/*
+	 * Eviction and purging are disabled by default, shmem user must enable
+	 * them explicitly using drm_gem_shmem_set_evictable/purgeable().
+	 */
+	shmem->eviction_disable_count = 1;
+	shmem->purge_disable_count = 1;
+
 	if (!private) {
 		/*
 		 * Our buffers are kept pinned, so allocating them
@@ -127,6 +134,77 @@ struct drm_gem_shmem_object *drm_gem_shmem_create(struct drm_device *dev, size_t
 }
 EXPORT_SYMBOL_GPL(drm_gem_shmem_create);
 
+static void
+drm_gem_shmem_add_pages_to_shrinker(struct drm_gem_shmem_object *shmem)
+{
+	struct drm_gem_object *obj = &shmem->base;
+	struct drm_gem_shmem_shrinker *gem_shrinker = obj->dev->shmem_shrinker;
+	size_t page_count = obj->size >> PAGE_SHIFT;
+
+	if (!shmem->pages_accounted_by_shrinker) {
+		WARN_ON(gem_shrinker->shrinkable_count + page_count < page_count);
+		gem_shrinker->shrinkable_count += page_count;
+		shmem->pages_accounted_by_shrinker = true;
+	}
+}
+
+static void
+drm_gem_shmem_remove_pages_from_shrinker(struct drm_gem_shmem_object *shmem)
+{
+	struct drm_gem_object *obj = &shmem->base;
+	struct drm_gem_shmem_shrinker *gem_shrinker = obj->dev->shmem_shrinker;
+	size_t page_count = obj->size >> PAGE_SHIFT;
+
+	if (shmem->pages_accounted_by_shrinker) {
+		WARN_ON(gem_shrinker->shrinkable_count < page_count);
+		gem_shrinker->shrinkable_count -= page_count;
+		shmem->pages_accounted_by_shrinker = false;
+	}
+}
+
+static bool drm_gem_shmem_is_evictable(struct drm_gem_shmem_object *shmem)
+{
+	return (shmem->madv >= 0) && !shmem->eviction_disable_count &&
+		!shmem->vmap_use_count && !shmem->base.dma_buf &&
+		!shmem->base.import_attach && shmem->sgt && !shmem->evicted;
+}
+
+static void
+drm_gem_shmem_update_pages_state_locked(struct drm_gem_shmem_object *shmem)
+{
+	struct drm_gem_object *obj = &shmem->base;
+	struct drm_gem_shmem_shrinker *gem_shrinker = obj->dev->shmem_shrinker;
+
+	if (!gem_shrinker || obj->import_attach)
+		return;
+
+	lockdep_assert_held(&obj->resv->lock.base);
+
+	mutex_lock(&gem_shrinker->lock);
+
+	if (drm_gem_shmem_is_purgeable(shmem) && !shmem->purge_disable_count) {
+		drm_gem_shmem_add_pages_to_shrinker(shmem);
+		list_move_tail(&shmem->madv_list, &gem_shrinker->lru_purgeable);
+	} else if (drm_gem_shmem_is_evictable(shmem)) {
+		drm_gem_shmem_add_pages_to_shrinker(shmem);
+		list_move_tail(&shmem->madv_list, &gem_shrinker->lru_evictable);
+	} else if (shmem->madv < 0) {
+		drm_gem_shmem_remove_pages_from_shrinker(shmem);
+		list_del_init(&shmem->madv_list);
+	} else if (shmem->evicted) {
+		drm_gem_shmem_remove_pages_from_shrinker(shmem);
+		list_move_tail(&shmem->madv_list, &gem_shrinker->lru_evicted);
+	} else if (!shmem->pages) {
+		drm_gem_shmem_remove_pages_from_shrinker(shmem);
+		list_del_init(&shmem->madv_list);
+	} else {
+		drm_gem_shmem_remove_pages_from_shrinker(shmem);
+		list_move_tail(&shmem->madv_list, &gem_shrinker->lru_active);
+	}
+
+	mutex_unlock(&gem_shrinker->lock);
+}
+
 /**
  * drm_gem_shmem_free - Free resources associated with a shmem GEM object
  * @shmem: shmem GEM object to free
@@ -138,6 +216,9 @@ void drm_gem_shmem_free(struct drm_gem_shmem_object *shmem)
 {
 	struct drm_gem_object *obj = &shmem->base;
 
+	/* take out shmem GEM object from the memory shrinker */
+	drm_gem_shmem_madvise(shmem, -1);
+
 	WARN_ON(shmem->vmap_use_count);
 
 	if (obj->import_attach) {
@@ -149,7 +230,7 @@ void drm_gem_shmem_free(struct drm_gem_shmem_object *shmem)
 			sg_free_table(shmem->sgt);
 			kfree(shmem->sgt);
 		}
-		if (shmem->pages)
+		if (shmem->pages_use_count)
 			drm_gem_shmem_put_pages(shmem);
 	}
 
@@ -160,18 +241,208 @@ void drm_gem_shmem_free(struct drm_gem_shmem_object *shmem)
 }
 EXPORT_SYMBOL_GPL(drm_gem_shmem_free);
 
-static int drm_gem_shmem_get_pages_locked(struct drm_gem_shmem_object *shmem)
+static int
+drm_gem_shmem_set_evictable_locked(struct drm_gem_shmem_object *shmem)
+{
+	struct drm_gem_object *obj = &shmem->base;
+	int ret = 0;
+
+	lockdep_assert_held(&obj->resv->lock.base);
+
+	WARN_ON_ONCE(!shmem->eviction_disable_count--);
+
+	if (shmem->madv < 0)
+		ret = -ENOMEM;
+
+	drm_gem_shmem_update_pages_state_locked(shmem);
+
+	return ret;
+}
+
+static int
+drm_gem_shmem_set_unevictable_locked(struct drm_gem_shmem_object *shmem)
+{
+	struct drm_gem_object *obj = &shmem->base;
+	int err;
+
+	lockdep_assert_held(&obj->resv->lock.base);
+
+	if (shmem->madv < 0)
+		return -ENOMEM;
+
+	if (shmem->evicted) {
+		err = drm_gem_shmem_swap_in_locked(shmem);
+		if (err)
+			return err;
+	}
+
+	shmem->eviction_disable_count++;
+
+	drm_gem_shmem_update_pages_state_locked(shmem);
+
+	return 0;
+}
+
+static int
+drm_gem_shmem_set_unpurgeable_locked(struct drm_gem_shmem_object *shmem)
+{
+	struct drm_gem_object *obj = &shmem->base;
+
+	lockdep_assert_held(&obj->resv->lock.base);
+
+	if (shmem->madv < 0)
+		return -ENOMEM;
+
+	shmem->purge_disable_count++;
+
+	drm_gem_shmem_update_pages_state_locked(shmem);
+
+	return 0;
+}
+
+static int
+drm_gem_shmem_set_purgeable_locked(struct drm_gem_shmem_object *shmem)
+{
+	struct drm_gem_object *obj = &shmem->base;
+	int ret = 0;
+
+	lockdep_assert_held(&obj->resv->lock.base);
+
+	WARN_ON_ONCE(!shmem->purge_disable_count--);
+
+	if (shmem->madv < 0)
+		ret = -ENOMEM;
+
+	drm_gem_shmem_update_pages_state_locked(shmem);
+
+	return ret;
+}
+
+/**
+ * drm_gem_shmem_set_purgeable() - Make GEM purgeable by memory shrinker
+ * @shmem: shmem GEM object
+ *
+ * Tell memory shrinker that this GEM can be purged. Initially purging is
+ * disabled for all GEMs. Each set_pureable() call must have corresponding
+ * set_unpureable() call. If GEM was purged, then -ENOMEM is returned.
+ *
+ * Returns:
+ * 0 on success or a negative error code on failure.
+ */
+int drm_gem_shmem_set_purgeable(struct drm_gem_shmem_object *shmem)
+{
+	int ret;
+
+	dma_resv_lock(shmem->base.resv, NULL);
+	ret = drm_gem_shmem_set_purgeable_locked(shmem);
+	dma_resv_unlock(shmem->base.resv);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(drm_gem_shmem_set_purgeable);
+
+static int
+drm_gem_shmem_set_purgeable_and_evictable_locked(struct drm_gem_shmem_object *shmem)
+{
+	int ret;
+
+	ret = drm_gem_shmem_set_evictable_locked(shmem);
+	if (!ret) {
+		ret = drm_gem_shmem_set_purgeable_locked(shmem);
+		if (ret)
+			drm_gem_shmem_set_unevictable_locked(shmem);
+	}
+
+	return ret;
+}
+
+static int
+drm_gem_shmem_set_unpurgeable_and_unevictable_locked(struct drm_gem_shmem_object *shmem)
+{
+	int ret;
+
+	ret = drm_gem_shmem_set_unpurgeable_locked(shmem);
+	if (!ret) {
+		ret = drm_gem_shmem_set_unevictable_locked(shmem);
+		if (ret)
+			drm_gem_shmem_set_purgeable_locked(shmem);
+	}
+
+	return ret;
+}
+
+/**
+ * drm_gem_shmem_set_purgeable_and_evictable() - Make GEM purgeable and
+ * 						 evictable by memory shrinker
+ * @shmem: shmem GEM object
+ *
+ * Tell memory shrinker that this GEM can be purged and evicted. Each
+ * set_unpurgeable_and_unevictable() call must have corresponding
+ * set_purgeable_and_evictable() call. If GEM was purged, then -ENOMEM
+ * is returned.
+ *
+ * Returns:
+ * 0 on success or a negative error code on failure.
+ */
+int drm_gem_shmem_set_purgeable_and_evictable(struct drm_gem_shmem_object *shmem)
+{
+	int ret;
+
+	dma_resv_lock(shmem->base.resv, NULL);
+	ret = drm_gem_shmem_set_purgeable_and_evictable_locked(shmem);
+	dma_resv_unlock(shmem->base.resv);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(drm_gem_shmem_set_purgeable_and_evictable);
+
+/**
+ * drm_gem_shmem_set_unpurgeable_and_unevictable() - Make GEM unpurgeable and
+ * 						     unevictable by memory shrinker
+ * @shmem: shmem GEM object
+ *
+ * Tell memory shrinker that this GEM can't be purged and evicted. Each
+ * set_purgeable_and_evictable() call must have corresponding
+ * set_unpurgeable_and_unevictable() call. If GEM was purged, then -ENOMEM
+ * is returned.
+ *
+ * Returns:
+ * 0 on success or a negative error code on failure.
+ */
+static int
+drm_gem_shmem_set_unpurgeable_and_unevictable(struct drm_gem_shmem_object *shmem)
+{
+	int ret;
+
+	ret = dma_resv_lock_interruptible(shmem->base.resv, NULL);
+	if (ret)
+		return ret;
+
+	ret = drm_gem_shmem_set_unpurgeable_and_unevictable_locked(shmem);
+	dma_resv_unlock(shmem->base.resv);
+
+	return ret;
+}
+
+static int
+drm_gem_shmem_acquire_pages_locked(struct drm_gem_shmem_object *shmem)
 {
 	struct drm_gem_object *obj = &shmem->base;
 	struct page **pages;
 
-	if (shmem->pages_use_count++ > 0)
+	if (shmem->madv < 0) {
+		WARN_ON(shmem->pages);
+		return -ENOMEM;
+	}
+
+	if (shmem->pages) {
+		WARN_ON(!shmem->evicted);
 		return 0;
+	}
 
 	pages = drm_gem_get_pages(obj);
 	if (IS_ERR(pages)) {
 		DRM_DEBUG_KMS("Failed to get pages (%ld)\n", PTR_ERR(pages));
-		shmem->pages_use_count = 0;
 		return PTR_ERR(pages);
 	}
 
@@ -190,6 +461,25 @@ static int drm_gem_shmem_get_pages_locked(struct drm_gem_shmem_object *shmem)
 	return 0;
 }
 
+static int drm_gem_shmem_get_pages_locked(struct drm_gem_shmem_object *shmem)
+{
+	int err;
+
+	if (shmem->madv < 0)
+		return -ENOMEM;
+
+	if (shmem->pages_use_count++ > 0)
+		return 0;
+
+	err = drm_gem_shmem_acquire_pages_locked(shmem);
+	if (err) {
+		shmem->pages_use_count = 0;
+		return err;
+	}
+
+	return 0;
+}
+
 /*
  * drm_gem_shmem_get_pages - Allocate backing pages for a shmem GEM object
  * @shmem: shmem GEM object
@@ -210,21 +500,38 @@ int drm_gem_shmem_get_pages(struct drm_gem_shmem_object *shmem)
 	if (ret)
 		return ret;
 	ret = drm_gem_shmem_get_pages_locked(shmem);
+
+	drm_gem_shmem_update_pages_state_locked(shmem);
+
 	dma_resv_unlock(shmem->base.resv);
 
 	return ret;
 }
 EXPORT_SYMBOL(drm_gem_shmem_get_pages);
 
-static void drm_gem_shmem_put_pages_locked(struct drm_gem_shmem_object *shmem)
+static void drm_gem_shmem_get_pages_no_fail(struct drm_gem_shmem_object *shmem)
 {
-	struct drm_gem_object *obj = &shmem->base;
+	WARN_ON(shmem->base.import_attach);
 
-	if (WARN_ON_ONCE(!shmem->pages_use_count))
-		return;
+	dma_resv_lock(shmem->base.resv, NULL);
 
-	if (--shmem->pages_use_count > 0)
+	if (drm_gem_shmem_get_pages_locked(shmem))
+		shmem->pages_use_count++;
+
+	drm_gem_shmem_update_pages_state_locked(shmem);
+
+	dma_resv_unlock(shmem->base.resv);
+}
+
+static void
+drm_gem_shmem_release_pages_locked(struct drm_gem_shmem_object *shmem)
+{
+	struct drm_gem_object *obj = &shmem->base;
+
+	if (!shmem->pages) {
+		WARN_ON(!shmem->evicted && shmem->madv >= 0);
 		return;
+	}
 
 #ifdef CONFIG_X86
 	if (shmem->map_wc)
@@ -237,6 +544,21 @@ static void drm_gem_shmem_put_pages_locked(struct drm_gem_shmem_object *shmem)
 	shmem->pages = NULL;
 }
 
+static void drm_gem_shmem_put_pages_locked(struct drm_gem_shmem_object *shmem)
+{
+	struct drm_gem_object *obj = &shmem->base;
+
+	lockdep_assert_held(&obj->resv->lock.base);
+
+	if (WARN_ON(!shmem->pages_use_count))
+		return;
+
+	if (--shmem->pages_use_count > 0)
+		return;
+
+	drm_gem_shmem_release_pages_locked(shmem);
+}
+
 /*
  * drm_gem_shmem_put_pages - Decrease use count on the backing pages for a shmem GEM object
  * @shmem: shmem GEM object
@@ -247,6 +569,7 @@ void drm_gem_shmem_put_pages(struct drm_gem_shmem_object *shmem)
 {
 	dma_resv_lock(shmem->base.resv, NULL);
 	drm_gem_shmem_put_pages_locked(shmem);
+	drm_gem_shmem_update_pages_state_locked(shmem);
 	dma_resv_unlock(shmem->base.resv);
 }
 EXPORT_SYMBOL(drm_gem_shmem_put_pages);
@@ -263,9 +586,21 @@ EXPORT_SYMBOL(drm_gem_shmem_put_pages);
  */
 int drm_gem_shmem_pin(struct drm_gem_shmem_object *shmem)
 {
+	int err;
+
 	WARN_ON(shmem->base.import_attach);
 
-	return drm_gem_shmem_get_pages(shmem);
+	err = drm_gem_shmem_set_unpurgeable_and_unevictable(shmem);
+	if (err)
+		return err;
+
+	err = drm_gem_shmem_get_pages(shmem);
+	if (err) {
+		drm_gem_shmem_set_purgeable_and_evictable(shmem);
+		return err;
+	}
+
+	return 0;
 }
 EXPORT_SYMBOL(drm_gem_shmem_pin);
 
@@ -281,6 +616,7 @@ void drm_gem_shmem_unpin(struct drm_gem_shmem_object *shmem)
 	WARN_ON(shmem->base.import_attach);
 
 	drm_gem_shmem_put_pages(shmem);
+	drm_gem_shmem_set_purgeable_and_evictable(shmem);
 }
 EXPORT_SYMBOL(drm_gem_shmem_unpin);
 
@@ -365,8 +701,18 @@ int drm_gem_shmem_vmap(struct drm_gem_shmem_object *shmem,
 
 	if (ret)
 		return ret;
+
+	ret = drm_gem_shmem_set_unpurgeable_and_unevictable_locked(shmem);
+	if (ret)
+		goto unlock;
+
 	ret = drm_gem_shmem_vmap_locked(shmem, map);
+	if (ret)
+		drm_gem_shmem_set_purgeable_and_evictable_locked(shmem);
+	else
+		drm_gem_shmem_update_pages_state_locked(shmem);
 
+unlock:
 	if (obj->import_attach)
 		mutex_unlock(&shmem->vmap_lock);
 	else
@@ -420,6 +766,8 @@ void drm_gem_shmem_vunmap(struct drm_gem_shmem_object *shmem,
 		dma_resv_lock(shmem->base.resv, NULL);
 
 	drm_gem_shmem_vunmap_locked(shmem, map);
+	drm_gem_shmem_update_pages_state_locked(shmem);
+	drm_gem_shmem_set_purgeable_and_evictable_locked(shmem);
 
 	if (obj->import_attach)
 		mutex_unlock(&shmem->vmap_lock);
@@ -465,12 +813,86 @@ int drm_gem_shmem_madvise(struct drm_gem_shmem_object *shmem, int madv)
 
 	madv = shmem->madv;
 
+	drm_gem_shmem_update_pages_state_locked(shmem);
+
 	dma_resv_unlock(shmem->base.resv);
 
 	return (madv >= 0);
 }
 EXPORT_SYMBOL(drm_gem_shmem_madvise);
 
+/**
+ * drm_gem_shmem_swap_in_locked() - Moves shmem GEM back to memory and enables
+ *                                  hardware access to the memory.
+ * @shmem: shmem GEM object
+ *
+ * This function moves shmem GEM back to memory if it was previously evicted
+ * by the memory shrinker. The GEM is ready to use on success.
+ *
+ * Returns:
+ * 0 on success or a negative error code on failure.
+ */
+int drm_gem_shmem_swap_in_locked(struct drm_gem_shmem_object *shmem)
+{
+	struct drm_gem_object *obj = &shmem->base;
+	struct sg_table *sgt;
+	int err;
+
+	lockdep_assert_held(&obj->resv->lock.base);
+
+	if (shmem->evicted) {
+		err = drm_gem_shmem_acquire_pages_locked(shmem);
+		if (err)
+			return err;
+
+		sgt = drm_gem_shmem_get_sg_table(shmem);
+		if (IS_ERR(sgt))
+			return PTR_ERR(sgt);
+
+		err = dma_map_sgtable(obj->dev->dev, sgt,
+				      DMA_BIDIRECTIONAL, 0);
+		if (err) {
+			sg_free_table(sgt);
+			kfree(sgt);
+			return err;
+		}
+
+		shmem->sgt = sgt;
+		shmem->evicted = false;
+
+		drm_gem_shmem_update_pages_state_locked(shmem);
+
+		if (shmem->swap_in) {
+			err = shmem->swap_in(shmem);
+			if (err)
+				return err;
+		}
+	}
+
+	if (!shmem->pages)
+		return -ENOMEM;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(drm_gem_shmem_swap_in_locked);
+
+static void drm_gem_shmem_unpin_pages_locked(struct drm_gem_shmem_object *shmem)
+{
+	struct drm_gem_object *obj = &shmem->base;
+	struct drm_device *dev = obj->dev;
+
+	if (shmem->evicted)
+		return;
+
+	dma_unmap_sgtable(dev->dev, shmem->sgt, DMA_BIDIRECTIONAL, 0);
+	drm_gem_shmem_release_pages_locked(shmem);
+	drm_vma_node_unmap(&obj->vma_node, dev->anon_inode->i_mapping);
+
+	sg_free_table(shmem->sgt);
+	kfree(shmem->sgt);
+	shmem->sgt = NULL;
+}
+
 void drm_gem_shmem_purge_locked(struct drm_gem_shmem_object *shmem)
 {
 	struct drm_gem_object *obj = &shmem->base;
@@ -501,17 +923,6 @@ void drm_gem_shmem_purge_locked(struct drm_gem_shmem_object *shmem)
 }
 EXPORT_SYMBOL(drm_gem_shmem_purge_locked);
 
-bool drm_gem_shmem_purge(struct drm_gem_shmem_object *shmem)
-{
-	if (!dma_resv_trylock(shmem->base.resv))
-		return false;
-	drm_gem_shmem_purge_locked(shmem);
-	dma_resv_unlock(shmem->base.resv);
-
-	return true;
-}
-EXPORT_SYMBOL(drm_gem_shmem_purge);
-
 /**
  * drm_gem_shmem_dumb_create - Create a dumb shmem buffer object
  * @file: DRM file structure to create the dumb buffer for
@@ -561,22 +972,31 @@ static vm_fault_t drm_gem_shmem_fault(struct vm_fault *vmf)
 	vm_fault_t ret;
 	struct page *page;
 	pgoff_t page_offset;
+	bool pages_inactive;
+	int err;
 
 	/* We don't use vmf->pgoff since that has the fake offset */
 	page_offset = (vmf->address - vma->vm_start) >> PAGE_SHIFT;
 
 	dma_resv_lock(shmem->base.resv, NULL);
 
-	if (page_offset >= num_pages ||
-	    WARN_ON_ONCE(!shmem->pages) ||
-	    shmem->madv < 0) {
+	pages_inactive = (shmem->evicted || shmem->madv < 0 || !shmem->pages_use_count);
+	WARN_ON_ONCE(!shmem->pages ^ pages_inactive);
+
+	if (page_offset >= num_pages || (!shmem->pages && !shmem->evicted)) {
 		ret = VM_FAULT_SIGBUS;
 	} else {
+		err = drm_gem_shmem_swap_in_locked(shmem);
+		if (err) {
+			ret = VM_FAULT_OOM;
+			goto unlock;
+		}
+
 		page = shmem->pages[page_offset];
 
 		ret = vmf_insert_pfn(vma, vmf->address, page_to_pfn(page));
 	}
-
+unlock:
 	dma_resv_unlock(shmem->base.resv);
 
 	return ret;
@@ -586,13 +1006,8 @@ static void drm_gem_shmem_vm_open(struct vm_area_struct *vma)
 {
 	struct drm_gem_object *obj = vma->vm_private_data;
 	struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj);
-	int ret;
-
-	WARN_ON(shmem->base.import_attach);
-
-	ret = drm_gem_shmem_get_pages(shmem);
-	WARN_ON_ONCE(ret != 0);
 
+	drm_gem_shmem_get_pages_no_fail(shmem);
 	drm_gem_vm_open(vma);
 }
 
@@ -660,9 +1075,13 @@ EXPORT_SYMBOL_GPL(drm_gem_shmem_mmap);
 void drm_gem_shmem_print_info(const struct drm_gem_shmem_object *shmem,
 			      struct drm_printer *p, unsigned int indent)
 {
+	drm_printf_indent(p, indent, "eviction_disable_count=%u\n", shmem->eviction_disable_count);
+	drm_printf_indent(p, indent, "purge_disable_count=%u\n", shmem->purge_disable_count);
 	drm_printf_indent(p, indent, "pages_use_count=%u\n", shmem->pages_use_count);
 	drm_printf_indent(p, indent, "vmap_use_count=%u\n", shmem->vmap_use_count);
+	drm_printf_indent(p, indent, "evicted=%d\n", shmem->evicted);
 	drm_printf_indent(p, indent, "vaddr=%p\n", shmem->vaddr);
+	drm_printf_indent(p, indent, "madv=%d\n", shmem->madv);
 }
 EXPORT_SYMBOL(drm_gem_shmem_print_info);
 
@@ -735,6 +1154,10 @@ struct sg_table *drm_gem_shmem_get_pages_sgt(struct drm_gem_shmem_object *shmem)
 
 	shmem->sgt = sgt;
 
+	dma_resv_lock(shmem->base.resv, NULL);
+	drm_gem_shmem_update_pages_state_locked(shmem);
+	dma_resv_unlock(shmem->base.resv);
+
 	return sgt;
 
 err_free_sgt:
@@ -781,6 +1204,255 @@ drm_gem_shmem_prime_import_sg_table(struct drm_device *dev,
 }
 EXPORT_SYMBOL_GPL(drm_gem_shmem_prime_import_sg_table);
 
+static struct drm_gem_shmem_shrinker *
+to_drm_shrinker(struct shrinker *shrinker)
+{
+	return container_of(shrinker, struct drm_gem_shmem_shrinker, base);
+}
+
+static unsigned long
+drm_gem_shmem_shrinker_count_objects(struct shrinker *shrinker,
+				     struct shrink_control *sc)
+{
+	struct drm_gem_shmem_shrinker *gem_shrinker = to_drm_shrinker(shrinker);
+	u64 count = READ_ONCE(gem_shrinker->shrinkable_count);
+
+	if (count >= SHRINK_EMPTY)
+		return SHRINK_EMPTY - 1;
+
+	return count ?: SHRINK_EMPTY;
+}
+
+static unsigned long drm_gem_shmem_evict(struct drm_gem_shmem_object *shmem)
+{
+	struct drm_gem_object *obj = &shmem->base;
+	int err;
+
+	if (!drm_gem_shmem_is_evictable(shmem))
+		return 0;
+
+	if (shmem->evict) {
+		err = shmem->evict(shmem);
+		if (err)
+			return 0;
+	}
+
+	WARN_ON(!drm_gem_shmem_is_evictable(shmem));
+	WARN_ON(shmem->madv < 0);
+	WARN_ON(shmem->evicted);
+
+	drm_gem_shmem_unpin_pages_locked(shmem);
+
+	shmem->evicted = true;
+	drm_gem_shmem_update_pages_state_locked(shmem);
+
+	return obj->size >> PAGE_SHIFT;
+}
+
+static unsigned long drm_gem_shmem_purge(struct drm_gem_shmem_object *shmem)
+{
+	struct drm_gem_object *obj = &shmem->base;
+	int err;
+
+	if (!drm_gem_shmem_is_purgeable(shmem))
+		return 0;
+
+	if (shmem->purge) {
+		err = shmem->purge(shmem);
+		if (err)
+			return 0;
+	}
+
+	WARN_ON(!drm_gem_shmem_is_purgeable(shmem));
+	WARN_ON(shmem->madv < 0);
+
+	drm_gem_shmem_unpin_pages_locked(shmem);
+	drm_gem_free_mmap_offset(obj);
+
+	/* Our goal here is to return as much of the memory as
+	 * is possible back to the system as we are called from OOM.
+	 * To do this we must instruct the shmfs to drop all of its
+	 * backing pages, *now*.
+	 */
+	shmem_truncate_range(file_inode(obj->filp), 0, (loff_t)-1);
+
+	invalidate_mapping_pages(file_inode(obj->filp)->i_mapping, 0, (loff_t)-1);
+
+	shmem->madv = -1;
+	drm_gem_shmem_update_pages_state_locked(shmem);
+
+	return obj->size >> PAGE_SHIFT;
+}
+
+static unsigned long
+drm_gem_shmem_shrinker_run_objects_scan(struct shrinker *shrinker,
+					unsigned long nr_to_scan,
+					bool *lock_contention,
+					bool evict)
+{
+	struct drm_gem_shmem_shrinker *gem_shrinker = to_drm_shrinker(shrinker);
+	struct drm_gem_shmem_object *shmem;
+	struct list_head still_in_list;
+	struct drm_gem_object *obj;
+	unsigned long freed = 0;
+	struct list_head *lru;
+	size_t page_count;
+
+	INIT_LIST_HEAD(&still_in_list);
+
+	mutex_lock(&gem_shrinker->lock);
+
+	if (evict)
+		lru = &gem_shrinker->lru_evictable;
+	else
+		lru = &gem_shrinker->lru_purgeable;
+
+	while (freed < nr_to_scan) {
+		shmem = list_first_entry_or_null(lru, typeof(*shmem), madv_list);
+		if (!shmem)
+			break;
+
+		obj = &shmem->base;
+		page_count = obj->size >> PAGE_SHIFT;
+		list_move_tail(&shmem->madv_list, &still_in_list);
+
+		if (evict && get_nr_swap_pages() < page_count)
+			continue;
+
+		/*
+		 * If it's in the process of being freed, gem_object->free()
+		 * may be blocked on lock waiting to remove it.  So just
+		 * skip it.
+		 */
+		if (!kref_get_unless_zero(&obj->refcount))
+			continue;
+
+		mutex_unlock(&gem_shrinker->lock);
+
+		/* prevent racing with job-submission code paths */
+		if (!dma_resv_trylock(obj->resv)) {
+			*lock_contention |= true;
+			goto shrinker_lock;
+		}
+
+		/* prevent racing with the dma-buf exporting */
+		if (!mutex_trylock(&gem_shrinker->dev->object_name_lock)) {
+			*lock_contention |= true;
+			goto resv_unlock;
+		}
+
+		/* check whether h/w uses this object */
+		if (!dma_resv_test_signaled(obj->resv, DMA_RESV_USAGE_WRITE))
+			goto object_name_unlock;
+
+		if (evict)
+			freed += drm_gem_shmem_evict(shmem);
+		else
+			freed += drm_gem_shmem_purge(shmem);
+
+object_name_unlock:
+		mutex_unlock(&gem_shrinker->dev->object_name_lock);
+resv_unlock:
+		dma_resv_unlock(obj->resv);
+shrinker_lock:
+		drm_gem_object_put(&shmem->base);
+		mutex_lock(&gem_shrinker->lock);
+	}
+
+	list_splice_tail(&still_in_list, lru);
+
+	mutex_unlock(&gem_shrinker->lock);
+
+	return freed;
+}
+
+static unsigned long
+drm_gem_shmem_shrinker_scan_objects(struct shrinker *shrinker,
+				    struct shrink_control *sc)
+{
+	unsigned long nr_to_scan = sc->nr_to_scan;
+	bool lock_contention = false;
+	unsigned long freed;
+
+	/* purge as many objects as we can */
+	freed = drm_gem_shmem_shrinker_run_objects_scan(shrinker, nr_to_scan,
+							&lock_contention, false);
+	nr_to_scan -= freed;
+
+	/* evict as many objects as we can */
+	if (freed < nr_to_scan)
+		freed += drm_gem_shmem_shrinker_run_objects_scan(shrinker,
+								 nr_to_scan,
+								 &lock_contention,
+								 true);
+
+	return (!freed && !lock_contention) ? SHRINK_STOP : freed;
+}
+
+/**
+ * drm_gem_shmem_shrinker_register() - Register shmem shrinker
+ * @dev: DRM device
+ *
+ * Returns:
+ * 0 on success or a negative error code on failure.
+ */
+int drm_gem_shmem_shrinker_register(struct drm_device *dev)
+{
+	struct drm_gem_shmem_shrinker *gem_shrinker;
+	int err;
+
+	if (WARN_ON(dev->shmem_shrinker))
+		return -EBUSY;
+
+	gem_shrinker = kzalloc(sizeof(*gem_shrinker), GFP_KERNEL);
+	if (!gem_shrinker)
+		return -ENOMEM;
+
+	gem_shrinker->base.count_objects = drm_gem_shmem_shrinker_count_objects;
+	gem_shrinker->base.scan_objects = drm_gem_shmem_shrinker_scan_objects;
+	gem_shrinker->base.seeks = DEFAULT_SEEKS;
+	gem_shrinker->dev = dev;
+
+	INIT_LIST_HEAD(&gem_shrinker->lru_purgeable);
+	INIT_LIST_HEAD(&gem_shrinker->lru_evictable);
+	INIT_LIST_HEAD(&gem_shrinker->lru_evicted);
+	INIT_LIST_HEAD(&gem_shrinker->lru_active);
+	mutex_init(&gem_shrinker->lock);
+
+	dev->shmem_shrinker = gem_shrinker;
+
+	err = register_shrinker(&gem_shrinker->base);
+	if (err) {
+		dev->shmem_shrinker = NULL;
+		kfree(gem_shrinker);
+		return err;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(drm_gem_shmem_shrinker_register);
+
+/**
+ * drm_gem_shmem_shrinker_unregister() - Unregister shmem shrinker
+ * @dev: DRM device
+ */
+void drm_gem_shmem_shrinker_unregister(struct drm_device *dev)
+{
+	struct drm_gem_shmem_shrinker *gem_shrinker = dev->shmem_shrinker;
+
+	if (gem_shrinker) {
+		unregister_shrinker(&gem_shrinker->base);
+		WARN_ON(!list_empty(&gem_shrinker->lru_purgeable));
+		WARN_ON(!list_empty(&gem_shrinker->lru_evictable));
+		WARN_ON(!list_empty(&gem_shrinker->lru_evicted));
+		WARN_ON(!list_empty(&gem_shrinker->lru_active));
+		mutex_destroy(&gem_shrinker->lock);
+		dev->shmem_shrinker = NULL;
+		kfree(gem_shrinker);
+	}
+}
+EXPORT_SYMBOL_GPL(drm_gem_shmem_shrinker_unregister);
+
 MODULE_DESCRIPTION("DRM SHMEM memory-management helpers");
 MODULE_IMPORT_NS(DMA_BUF);
 MODULE_LICENSE("GPL v2");
diff --git a/include/drm/drm_device.h b/include/drm/drm_device.h
index 9923c7a6885e..929546cad894 100644
--- a/include/drm/drm_device.h
+++ b/include/drm/drm_device.h
@@ -16,6 +16,7 @@ struct drm_vblank_crtc;
 struct drm_vma_offset_manager;
 struct drm_vram_mm;
 struct drm_fb_helper;
+struct drm_gem_shmem_shrinker;
 
 struct inode;
 
@@ -277,6 +278,9 @@ struct drm_device {
 	/** @vram_mm: VRAM MM memory manager */
 	struct drm_vram_mm *vram_mm;
 
+	/** @shmem_shrinker: SHMEM GEM memory shrinker */
+	struct drm_gem_shmem_shrinker *shmem_shrinker;
+
 	/**
 	 * @switch_power_state:
 	 *
diff --git a/include/drm/drm_gem_shmem_helper.h b/include/drm/drm_gem_shmem_helper.h
index 6f2b8fee620c..638cb16a4576 100644
--- a/include/drm/drm_gem_shmem_helper.h
+++ b/include/drm/drm_gem_shmem_helper.h
@@ -6,6 +6,7 @@
 #include <linux/fs.h>
 #include <linux/mm.h>
 #include <linux/mutex.h>
+#include <linux/shrinker.h>
 
 #include <drm/drm_file.h>
 #include <drm/drm_gem.h>
@@ -15,6 +16,7 @@
 struct dma_buf_attachment;
 struct drm_mode_create_dumb;
 struct drm_printer;
+struct drm_device;
 struct sg_table;
 
 /**
@@ -43,8 +45,8 @@ struct drm_gem_shmem_object {
 	 * @madv: State for madvise
 	 *
 	 * 0 is active/inuse.
+	 * 1 is not-needed/can-be-purged
 	 * A negative value is the object is purged.
-	 * Positive values are driver specific and not used by the helpers.
 	 */
 	int madv;
 
@@ -96,6 +98,80 @@ struct drm_gem_shmem_object {
 	 * @map_wc: map object write-combined (instead of using shmem defaults).
 	 */
 	bool map_wc;
+
+	/**
+	 * @eviction_disable_count:
+	 *
+	 * The shmem pages are disallowed to be evicted by the memory shrinker
+	 * while count is non-zero. Used internally by memory shrinker.
+	 */
+	unsigned int eviction_disable_count;
+
+	/**
+	 * @purge_disable_count:
+	 *
+	 * The shmem pages are disallowed to be purged by the memory shrinker
+	 * while count is non-zero. Used internally by memory shrinker.
+	 */
+	unsigned int purge_disable_count;
+
+	/**
+	 * @evicted: True if shmem pages were evicted by the memory shrinker.
+	 * Used internally by memory shrinker.
+	 */
+	bool evicted;
+
+	/**
+	 * @pages_accounted_by_shrinker: True if shmem pages can be evicted or
+	 * purged by the memory shrinker. Used internally by memory shrinker
+	 * to prevent double accounting of shrinkable pages.
+	 */
+	bool pages_accounted_by_shrinker;
+
+	/**
+	 * @swap_in:
+	 *
+	 * Invoked by shmem shrinker after pinning shmem GEM pages to memory.
+	 * GEM's DMA reservation is locked by the shrinker during invocation.
+	 * This callback is intended for DRM drivers that need to do something
+	 * special to make pages accessible to hardware after they've been
+	 * pinned.
+	 *
+	 * Returns 0 on success, or -errno on error.
+	 *
+	 * This callback is optional and should be set by drivers.
+	 */
+	int (*swap_in)(struct drm_gem_shmem_object *shmem);
+
+	/**
+	 * @evict:
+	 *
+	 * Invoked by shmem shrinker before unpinning shmem GEM pages from memory.
+	 * GEM's DMA reservation is locked by the shrinker during invocation.
+	 * This callback is intended for DRM drivers that need to do something
+	 * special to make pages unaccessible to hardware before they are
+	 * swapped out.
+	 *
+	 * Returns 0 on success, or -errno on error.
+	 *
+	 * This callback is optional and should be set by drivers.
+	 */
+	int (*evict)(struct drm_gem_shmem_object *shmem);
+
+	/**
+	 * @purge:
+	 *
+	 * Invoked by shmem shrinker before permanently purging shmem GEM pages.
+	 * GEM's DMA reservation is locked by the shrinker during invocation.
+	 * This callback is intended for DRM drivers that need to do something
+	 * special to make pages unaccessible to hardware before they are
+	 * purged.
+	 *
+	 * Returns 0 on success, or -errno on error.
+	 *
+	 * This callback is optional and should be set by drivers.
+	 */
+	int (*purge)(struct drm_gem_shmem_object *shmem);
 };
 
 #define to_drm_gem_shmem_obj(obj) \
@@ -116,6 +192,9 @@ int drm_gem_shmem_mmap(struct drm_gem_shmem_object *shmem, struct vm_area_struct
 
 int drm_gem_shmem_madvise(struct drm_gem_shmem_object *shmem, int madv);
 
+int drm_gem_shmem_set_purgeable(struct drm_gem_shmem_object *shmem);
+int drm_gem_shmem_set_purgeable_and_evictable(struct drm_gem_shmem_object *shmem);
+
 static inline bool drm_gem_shmem_is_purgeable(struct drm_gem_shmem_object *shmem)
 {
 	return (shmem->madv > 0) &&
@@ -123,8 +202,8 @@ static inline bool drm_gem_shmem_is_purgeable(struct drm_gem_shmem_object *shmem
 		!shmem->base.dma_buf && !shmem->base.import_attach;
 }
 
+int drm_gem_shmem_swap_in_locked(struct drm_gem_shmem_object *shmem);
 void drm_gem_shmem_purge_locked(struct drm_gem_shmem_object *shmem);
-bool drm_gem_shmem_purge(struct drm_gem_shmem_object *shmem);
 
 struct sg_table *drm_gem_shmem_get_sg_table(struct drm_gem_shmem_object *shmem);
 struct sg_table *drm_gem_shmem_get_pages_sgt(struct drm_gem_shmem_object *shmem);
@@ -267,6 +346,38 @@ static inline int drm_gem_shmem_object_mmap(struct drm_gem_object *obj, struct v
 	return drm_gem_shmem_mmap(shmem, vma);
 }
 
+/**
+ * struct drm_gem_shmem_shrinker - Generic memory shrinker for shmem GEMs
+ */
+struct drm_gem_shmem_shrinker {
+	/** @base: Shrinker for purging shmem GEM objects */
+	struct shrinker base;
+
+	/** @lock: Protects @lru_* */
+	struct mutex lock;
+
+	/** @lru_purgeable: List of shmem GEM objects that can be purged */
+	struct list_head lru_purgeable;
+
+	/** @lru_active: List of active shmem GEM objects */
+	struct list_head lru_active;
+
+	/** @lru_evictable: List of shmem GEM objects that can be evicted */
+	struct list_head lru_evictable;
+
+	/** @lru_evicted: List of evicted shmem GEM objects */
+	struct list_head lru_evicted;
+
+	/** @dev: DRM device that uses this shrinker */
+	struct drm_device *dev;
+
+	/** @shrinkable_count: Count of shmem GEM pages to be purged and evicted */
+	u64 shrinkable_count;
+};
+
+int drm_gem_shmem_shrinker_register(struct drm_device *dev);
+void drm_gem_shmem_shrinker_unregister(struct drm_device *dev);
+
 /*
  * Driver ops
  */
-- 
2.35.1

[PATCH v5 13/17] drm/virtio: Support memory shrinking

[Dmitry Osipenko]

Support generic DRM SHMEM memory shrinker and add new madvise IOCTL
to the VirtIO-GPU driver. Userspace (BO cache manager of Mesa driver)
will mark BOs as "don't need" using the new IOCTL to let shrinker purge
the marked BOs on OOM, the shrinker will also evict unpurgeable shmem BOs
from memory if guest supports SWAP. Altogether this allows to prevent OOM
kills of guest applications that use VirGL by lowering memory pressure.

Signed-off-by: Daniel Almeida <daniel.almeida@collabora.com>
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
---
 drivers/gpu/drm/virtio/virtgpu_drv.h    |  15 ++-
 drivers/gpu/drm/virtio/virtgpu_gem.c    |  46 +++++++++
 drivers/gpu/drm/virtio/virtgpu_ioctl.c  |  37 +++++++
 drivers/gpu/drm/virtio/virtgpu_kms.c    |   9 ++
 drivers/gpu/drm/virtio/virtgpu_object.c | 130 +++++++++++++++++++-----
 drivers/gpu/drm/virtio/virtgpu_plane.c  |  22 +++-
 drivers/gpu/drm/virtio/virtgpu_vq.c     |  40 ++++++++
 include/uapi/drm/virtgpu_drm.h          |  14 +++
 8 files changed, 283 insertions(+), 30 deletions(-)

diff --git a/drivers/gpu/drm/virtio/virtgpu_drv.h b/drivers/gpu/drm/virtio/virtgpu_drv.h
index b2d93cb12ebf..c8918a271e1c 100644
--- a/drivers/gpu/drm/virtio/virtgpu_drv.h
+++ b/drivers/gpu/drm/virtio/virtgpu_drv.h
@@ -274,7 +274,7 @@ struct virtio_gpu_fpriv {
 };
 
 /* virtgpu_ioctl.c */
-#define DRM_VIRTIO_NUM_IOCTLS 12
+#define DRM_VIRTIO_NUM_IOCTLS 13
 extern struct drm_ioctl_desc virtio_gpu_ioctls[DRM_VIRTIO_NUM_IOCTLS];
 void virtio_gpu_create_context(struct drm_device *dev, struct drm_file *file);
 
@@ -310,6 +310,10 @@ void virtio_gpu_array_put_free(struct virtio_gpu_object_array *objs);
 void virtio_gpu_array_put_free_delayed(struct virtio_gpu_device *vgdev,
 				       struct virtio_gpu_object_array *objs);
 void virtio_gpu_array_put_free_work(struct work_struct *work);
+int virtio_gpu_array_prepare(struct virtio_gpu_device *vgdev,
+			     struct virtio_gpu_object_array *objs);
+int virtio_gpu_gem_host_mem_release(struct virtio_gpu_object *bo);
+bool virtio_gpu_gem_madvise(struct virtio_gpu_object *obj, int madv);
 
 /* virtgpu_vq.c */
 int virtio_gpu_alloc_vbufs(struct virtio_gpu_device *vgdev);
@@ -321,6 +325,8 @@ void virtio_gpu_cmd_create_resource(struct virtio_gpu_device *vgdev,
 				    struct virtio_gpu_fence *fence);
 void virtio_gpu_cmd_unref_resource(struct virtio_gpu_device *vgdev,
 				   struct virtio_gpu_object *bo);
+int virtio_gpu_cmd_release_resource(struct virtio_gpu_device *vgdev,
+				    struct virtio_gpu_object *bo);
 void virtio_gpu_cmd_transfer_to_host_2d(struct virtio_gpu_device *vgdev,
 					uint64_t offset,
 					uint32_t width, uint32_t height,
@@ -341,6 +347,9 @@ void virtio_gpu_object_attach(struct virtio_gpu_device *vgdev,
 			      struct virtio_gpu_object *obj,
 			      struct virtio_gpu_mem_entry *ents,
 			      unsigned int nents);
+void virtio_gpu_object_detach(struct virtio_gpu_device *vgdev,
+			      struct virtio_gpu_object *obj,
+			      struct virtio_gpu_fence *fence);
 int virtio_gpu_attach_status_page(struct virtio_gpu_device *vgdev);
 int virtio_gpu_detach_status_page(struct virtio_gpu_device *vgdev);
 void virtio_gpu_cursor_ping(struct virtio_gpu_device *vgdev,
@@ -483,4 +492,8 @@ void virtio_gpu_vram_unmap_dma_buf(struct device *dev,
 				   struct sg_table *sgt,
 				   enum dma_data_direction dir);
 
+/* virtgpu_gem_shrinker.c */
+int virtio_gpu_gem_shrinker_init(struct virtio_gpu_device *vgdev);
+void virtio_gpu_gem_shrinker_fini(struct virtio_gpu_device *vgdev);
+
 #endif
diff --git a/drivers/gpu/drm/virtio/virtgpu_gem.c b/drivers/gpu/drm/virtio/virtgpu_gem.c
index 7db48d17ee3a..08189ad43736 100644
--- a/drivers/gpu/drm/virtio/virtgpu_gem.c
+++ b/drivers/gpu/drm/virtio/virtgpu_gem.c
@@ -294,3 +294,49 @@ void virtio_gpu_array_put_free_work(struct work_struct *work)
 	}
 	spin_unlock(&vgdev->obj_free_lock);
 }
+
+int virtio_gpu_array_prepare(struct virtio_gpu_device *vgdev,
+			     struct virtio_gpu_object_array *objs)
+{
+	struct drm_gem_shmem_object *shmem;
+	int ret = 0;
+	u32 i;
+
+	for (i = 0; i < objs->nents; i++) {
+		shmem = to_drm_gem_shmem_obj(objs->objs[i]);
+		ret = drm_gem_shmem_swap_in_locked(shmem);
+		if (ret)
+			break;
+	}
+
+	return ret;
+}
+
+bool virtio_gpu_gem_madvise(struct virtio_gpu_object *bo, int madv)
+{
+	/*
+	 * For now we support only purging BOs that are backed by guest's
+	 * memory.
+	 */
+	if (!virtio_gpu_is_shmem(bo))
+		return true;
+
+	return drm_gem_shmem_madvise(&bo->base, madv);
+}
+
+int virtio_gpu_gem_host_mem_release(struct virtio_gpu_object *bo)
+{
+	struct virtio_gpu_device *vgdev = bo->base.base.dev->dev_private;
+	int err;
+
+	if (bo->created) {
+		err = virtio_gpu_cmd_release_resource(vgdev, bo);
+		if (err)
+			return err;
+
+		virtio_gpu_notify(vgdev);
+		bo->created = false;
+	}
+
+	return 0;
+}
diff --git a/drivers/gpu/drm/virtio/virtgpu_ioctl.c b/drivers/gpu/drm/virtio/virtgpu_ioctl.c
index f8d83358d2a0..55ee9bd2098e 100644
--- a/drivers/gpu/drm/virtio/virtgpu_ioctl.c
+++ b/drivers/gpu/drm/virtio/virtgpu_ioctl.c
@@ -217,6 +217,10 @@ static int virtio_gpu_execbuffer_ioctl(struct drm_device *dev, void *data,
 		ret = virtio_gpu_array_lock_resv(buflist);
 		if (ret)
 			goto out_memdup;
+
+		ret = virtio_gpu_array_prepare(vgdev, buflist);
+		if (ret)
+			goto out_unresv;
 	}
 
 	out_fence = virtio_gpu_fence_alloc(vgdev, fence_ctx, ring_idx);
@@ -423,6 +427,10 @@ static int virtio_gpu_transfer_from_host_ioctl(struct drm_device *dev,
 	if (ret != 0)
 		goto err_put_free;
 
+	ret = virtio_gpu_array_prepare(vgdev, objs);
+	if (ret)
+		goto err_unlock;
+
 	fence = virtio_gpu_fence_alloc(vgdev, vgdev->fence_drv.context, 0);
 	if (!fence) {
 		ret = -ENOMEM;
@@ -482,6 +490,10 @@ static int virtio_gpu_transfer_to_host_ioctl(struct drm_device *dev, void *data,
 		if (ret != 0)
 			goto err_put_free;
 
+		ret = virtio_gpu_array_prepare(vgdev, objs);
+		if (ret)
+			goto err_unlock;
+
 		ret = -ENOMEM;
 		fence = virtio_gpu_fence_alloc(vgdev, vgdev->fence_drv.context,
 					       0);
@@ -836,6 +848,28 @@ static int virtio_gpu_context_init_ioctl(struct drm_device *dev,
 	return ret;
 }
 
+static int virtio_gpu_madvise_ioctl(struct drm_device *dev,
+				    void *data,
+				    struct drm_file *file)
+{
+	struct drm_virtgpu_madvise *args = data;
+	struct virtio_gpu_object *bo;
+	struct drm_gem_object *obj;
+
+	if (args->madv > VIRTGPU_MADV_DONTNEED)
+		return -EOPNOTSUPP;
+
+	obj = drm_gem_object_lookup(file, args->bo_handle);
+	if (!obj)
+		return -ENOENT;
+
+	bo = gem_to_virtio_gpu_obj(obj);
+	args->retained = virtio_gpu_gem_madvise(bo, args->madv);
+	drm_gem_object_put(obj);
+
+	return 0;
+}
+
 struct drm_ioctl_desc virtio_gpu_ioctls[DRM_VIRTIO_NUM_IOCTLS] = {
 	DRM_IOCTL_DEF_DRV(VIRTGPU_MAP, virtio_gpu_map_ioctl,
 			  DRM_RENDER_ALLOW),
@@ -875,4 +909,7 @@ struct drm_ioctl_desc virtio_gpu_ioctls[DRM_VIRTIO_NUM_IOCTLS] = {
 
 	DRM_IOCTL_DEF_DRV(VIRTGPU_CONTEXT_INIT, virtio_gpu_context_init_ioctl,
 			  DRM_RENDER_ALLOW),
+
+	DRM_IOCTL_DEF_DRV(VIRTGPU_MADVISE, virtio_gpu_madvise_ioctl,
+			  DRM_RENDER_ALLOW),
 };
diff --git a/drivers/gpu/drm/virtio/virtgpu_kms.c b/drivers/gpu/drm/virtio/virtgpu_kms.c
index 0d1e3eb61bee..1175999acea1 100644
--- a/drivers/gpu/drm/virtio/virtgpu_kms.c
+++ b/drivers/gpu/drm/virtio/virtgpu_kms.c
@@ -238,6 +238,12 @@ int virtio_gpu_init(struct virtio_device *vdev, struct drm_device *dev)
 		goto err_scanouts;
 	}
 
+	ret = drm_gem_shmem_shrinker_register(dev);
+	if (ret) {
+		DRM_ERROR("shrinker init failed\n");
+		goto err_modeset;
+	}
+
 	virtio_device_ready(vgdev->vdev);
 
 	if (num_capsets)
@@ -250,6 +256,8 @@ int virtio_gpu_init(struct virtio_device *vdev, struct drm_device *dev)
 			   5 * HZ);
 	return 0;
 
+err_modeset:
+	virtio_gpu_modeset_fini(vgdev);
 err_scanouts:
 	virtio_gpu_free_vbufs(vgdev);
 err_vbufs:
@@ -289,6 +297,7 @@ void virtio_gpu_release(struct drm_device *dev)
 	if (!vgdev)
 		return;
 
+	drm_gem_shmem_shrinker_unregister(dev);
 	virtio_gpu_modeset_fini(vgdev);
 	virtio_gpu_free_vbufs(vgdev);
 	virtio_gpu_cleanup_cap_cache(vgdev);
diff --git a/drivers/gpu/drm/virtio/virtgpu_object.c b/drivers/gpu/drm/virtio/virtgpu_object.c
index 8d7728181de0..fc8f2a78fd1d 100644
--- a/drivers/gpu/drm/virtio/virtgpu_object.c
+++ b/drivers/gpu/drm/virtio/virtgpu_object.c
@@ -97,41 +97,53 @@ static void virtio_gpu_free_object(struct drm_gem_object *obj)
 	virtio_gpu_cleanup_object(bo);
 }
 
-static const struct drm_gem_object_funcs virtio_gpu_shmem_funcs = {
-	.free = virtio_gpu_free_object,
-	.open = virtio_gpu_gem_object_open,
-	.close = virtio_gpu_gem_object_close,
-	.print_info = drm_gem_shmem_object_print_info,
-	.export = virtgpu_gem_prime_export,
-	.pin = drm_gem_shmem_object_pin,
-	.unpin = drm_gem_shmem_object_unpin,
-	.get_sg_table = drm_gem_shmem_object_get_sg_table,
-	.vmap = drm_gem_shmem_object_vmap,
-	.vunmap = drm_gem_shmem_object_vunmap,
-	.mmap = drm_gem_shmem_object_mmap,
-	.vm_ops = &drm_gem_shmem_vm_ops,
-};
-
-bool virtio_gpu_is_shmem(struct virtio_gpu_object *bo)
+static int virtio_gpu_detach_object_fenced(struct virtio_gpu_object *bo)
 {
-	return bo->base.base.funcs == &virtio_gpu_shmem_funcs;
+	struct virtio_gpu_device *vgdev = bo->base.base.dev->dev_private;
+	struct virtio_gpu_fence *fence;
+
+	fence = virtio_gpu_fence_alloc(vgdev, vgdev->fence_drv.context, 0);
+	if (!fence)
+		return -ENOMEM;
+
+	virtio_gpu_object_detach(vgdev, bo, fence);
+	virtio_gpu_notify(vgdev);
+
+	dma_fence_wait(&fence->f, false);
+	dma_fence_put(&fence->f);
+
+	return 0;
 }
 
-struct drm_gem_object *virtio_gpu_create_object(struct drm_device *dev,
-						size_t size)
+static int virtio_gpu_shmem_purge(struct drm_gem_shmem_object *shmem)
 {
-	struct virtio_gpu_object_shmem *shmem;
-	struct drm_gem_shmem_object *dshmem;
+	struct virtio_gpu_object *bo = gem_to_virtio_gpu_obj(&shmem->base);
+	int err;
 
-	shmem = kzalloc(sizeof(*shmem), GFP_KERNEL);
-	if (!shmem)
-		return ERR_PTR(-ENOMEM);
+	/*
+	 * At first tell host to stop using guest's memory to ensure that
+	 * host won't touch the released guest's memory once it's gone.
+	 */
+	err = virtio_gpu_detach_object_fenced(bo);
+	if (err)
+		return err;
 
-	dshmem = &shmem->base.base;
-	dshmem->base.funcs = &virtio_gpu_shmem_funcs;
-	return &dshmem->base;
+	err = virtio_gpu_gem_host_mem_release(bo);
+	if (err)
+		return err;
+
+	return 0;
+}
+
+static int virtio_gpu_shmem_evict(struct drm_gem_shmem_object *shmem)
+{
+	struct virtio_gpu_object *bo = gem_to_virtio_gpu_obj(&shmem->base);
+
+	return virtio_gpu_detach_object_fenced(bo);
 }
 
+static int virtio_gpu_shmem_swap_in(struct drm_gem_shmem_object *shmem);
+
 static int virtio_gpu_object_shmem_init(struct virtio_gpu_device *vgdev,
 					struct virtio_gpu_object *bo,
 					struct virtio_gpu_mem_entry **ents,
@@ -176,6 +188,59 @@ static int virtio_gpu_object_shmem_init(struct virtio_gpu_device *vgdev,
 	return 0;
 }
 
+static int virtio_gpu_shmem_swap_in(struct drm_gem_shmem_object *shmem)
+{
+	struct virtio_gpu_object *bo = gem_to_virtio_gpu_obj(&shmem->base);
+	struct virtio_gpu_device *vgdev = bo->base.base.dev->dev_private;
+	struct virtio_gpu_mem_entry *ents;
+	unsigned int nents;
+	int err;
+
+	err = virtio_gpu_object_shmem_init(vgdev, bo, &ents, &nents);
+	if (err)
+		return err;
+
+	virtio_gpu_object_attach(vgdev, bo, ents, nents);
+	virtio_gpu_notify(vgdev);
+
+	return 0;
+}
+
+static const struct drm_gem_object_funcs virtio_gpu_shmem_funcs = {
+	.free = virtio_gpu_free_object,
+	.open = virtio_gpu_gem_object_open,
+	.close = virtio_gpu_gem_object_close,
+	.print_info = drm_gem_shmem_object_print_info,
+	.export = virtgpu_gem_prime_export,
+	.pin = drm_gem_shmem_object_pin,
+	.unpin = drm_gem_shmem_object_unpin,
+	.get_sg_table = drm_gem_shmem_object_get_sg_table,
+	.vmap = drm_gem_shmem_object_vmap,
+	.vunmap = drm_gem_shmem_object_vunmap,
+	.mmap = drm_gem_shmem_object_mmap,
+	.vm_ops = &drm_gem_shmem_vm_ops,
+};
+
+bool virtio_gpu_is_shmem(struct virtio_gpu_object *bo)
+{
+	return bo->base.base.funcs == &virtio_gpu_shmem_funcs;
+}
+
+struct drm_gem_object *virtio_gpu_create_object(struct drm_device *dev,
+						size_t size)
+{
+	struct virtio_gpu_object_shmem *shmem;
+	struct drm_gem_shmem_object *dshmem;
+
+	shmem = kzalloc(sizeof(*shmem), GFP_KERNEL);
+	if (!shmem)
+		return ERR_PTR(-ENOMEM);
+
+	dshmem = &shmem->base.base;
+	dshmem->base.funcs = &virtio_gpu_shmem_funcs;
+	return &dshmem->base;
+}
+
 int virtio_gpu_object_create(struct virtio_gpu_device *vgdev,
 			     struct virtio_gpu_object_params *params,
 			     struct virtio_gpu_object **bo_ptr,
@@ -201,6 +266,9 @@ int virtio_gpu_object_create(struct virtio_gpu_device *vgdev,
 		goto err_free_gem;
 
 	bo->dumb = params->dumb;
+	bo->base.purge = virtio_gpu_shmem_purge;
+	bo->base.evict = virtio_gpu_shmem_evict;
+	bo->base.swap_in = virtio_gpu_shmem_swap_in;
 
 	ret = virtio_gpu_object_shmem_init(vgdev, bo, &ents, &nents);
 	if (ret != 0)
@@ -228,10 +296,18 @@ int virtio_gpu_object_create(struct virtio_gpu_device *vgdev,
 		virtio_gpu_cmd_resource_create_3d(vgdev, bo, params,
 						  objs, fence);
 		virtio_gpu_object_attach(vgdev, bo, ents, nents);
+
+		shmem_obj->pages_mark_dirty_on_put = 1;
+
+		drm_gem_shmem_set_purgeable_and_evictable(shmem_obj);
 	} else {
 		virtio_gpu_cmd_create_resource(vgdev, bo, params,
 					       objs, fence);
 		virtio_gpu_object_attach(vgdev, bo, ents, nents);
+
+		shmem_obj->pages_mark_dirty_on_put = 1;
+
+		drm_gem_shmem_set_purgeable_and_evictable(shmem_obj);
 	}
 
 	*bo_ptr = bo;
diff --git a/drivers/gpu/drm/virtio/virtgpu_plane.c b/drivers/gpu/drm/virtio/virtgpu_plane.c
index 7148f3813d8b..c3ac77cae555 100644
--- a/drivers/gpu/drm/virtio/virtgpu_plane.c
+++ b/drivers/gpu/drm/virtio/virtgpu_plane.c
@@ -246,20 +246,32 @@ static int virtio_gpu_plane_prepare_fb(struct drm_plane *plane,
 	struct virtio_gpu_device *vgdev = dev->dev_private;
 	struct virtio_gpu_framebuffer *vgfb;
 	struct virtio_gpu_object *bo;
+	int err;
 
 	if (!new_state->fb)
 		return 0;
 
 	vgfb = to_virtio_gpu_framebuffer(new_state->fb);
 	bo = gem_to_virtio_gpu_obj(vgfb->base.obj[0]);
-	if (!bo || (plane->type == DRM_PLANE_TYPE_PRIMARY && !bo->guest_blob))
+
+	if (virtio_gpu_is_shmem(bo)) {
+		err = drm_gem_shmem_pin(&bo->base);
+		if (err)
+			return err;
+	}
+
+	if (plane->type == DRM_PLANE_TYPE_PRIMARY && !bo->guest_blob)
 		return 0;
 
 	if (bo->dumb && (plane->state->fb != new_state->fb)) {
 		vgfb->fence = virtio_gpu_fence_alloc(vgdev, vgdev->fence_drv.context,
 						     0);
-		if (!vgfb->fence)
+		if (!vgfb->fence) {
+			if (virtio_gpu_is_shmem(bo))
+				drm_gem_shmem_unpin(&bo->base);
+
 			return -ENOMEM;
+		}
 	}
 
 	return 0;
@@ -269,15 +281,21 @@ static void virtio_gpu_plane_cleanup_fb(struct drm_plane *plane,
 					struct drm_plane_state *state)
 {
 	struct virtio_gpu_framebuffer *vgfb;
+	struct virtio_gpu_object *bo;
 
 	if (!state->fb)
 		return;
 
 	vgfb = to_virtio_gpu_framebuffer(state->fb);
+	bo = gem_to_virtio_gpu_obj(vgfb->base.obj[0]);
+
 	if (vgfb->fence) {
 		dma_fence_put(&vgfb->fence->f);
 		vgfb->fence = NULL;
 	}
+
+	if (virtio_gpu_is_shmem(bo))
+		drm_gem_shmem_unpin(&bo->base);
 }
 
 static void virtio_gpu_cursor_plane_update(struct drm_plane *plane,
diff --git a/drivers/gpu/drm/virtio/virtgpu_vq.c b/drivers/gpu/drm/virtio/virtgpu_vq.c
index 06566e44307d..2a04dad1ae89 100644
--- a/drivers/gpu/drm/virtio/virtgpu_vq.c
+++ b/drivers/gpu/drm/virtio/virtgpu_vq.c
@@ -536,6 +536,21 @@ void virtio_gpu_cmd_unref_resource(struct virtio_gpu_device *vgdev,
 		virtio_gpu_cleanup_object(bo);
 }
 
+int virtio_gpu_cmd_release_resource(struct virtio_gpu_device *vgdev,
+				    struct virtio_gpu_object *bo)
+{
+	struct virtio_gpu_resource_unref *cmd_p;
+	struct virtio_gpu_vbuffer *vbuf;
+
+	cmd_p = virtio_gpu_alloc_cmd(vgdev, &vbuf, sizeof(*cmd_p));
+	memset(cmd_p, 0, sizeof(*cmd_p));
+
+	cmd_p->hdr.type = cpu_to_le32(VIRTIO_GPU_CMD_RESOURCE_UNREF);
+	cmd_p->resource_id = cpu_to_le32(bo->hw_res_handle);
+
+	return virtio_gpu_queue_ctrl_buffer(vgdev, vbuf);
+}
+
 void virtio_gpu_cmd_set_scanout(struct virtio_gpu_device *vgdev,
 				uint32_t scanout_id, uint32_t resource_id,
 				uint32_t width, uint32_t height,
@@ -636,6 +651,23 @@ virtio_gpu_cmd_resource_attach_backing(struct virtio_gpu_device *vgdev,
 	virtio_gpu_queue_fenced_ctrl_buffer(vgdev, vbuf, fence);
 }
 
+static void
+virtio_gpu_cmd_resource_detach_backing(struct virtio_gpu_device *vgdev,
+				       u32 resource_id,
+				       struct virtio_gpu_fence *fence)
+{
+	struct virtio_gpu_resource_attach_backing *cmd_p;
+	struct virtio_gpu_vbuffer *vbuf;
+
+	cmd_p = virtio_gpu_alloc_cmd(vgdev, &vbuf, sizeof(*cmd_p));
+	memset(cmd_p, 0, sizeof(*cmd_p));
+
+	cmd_p->hdr.type = cpu_to_le32(VIRTIO_GPU_CMD_RESOURCE_DETACH_BACKING);
+	cmd_p->resource_id = cpu_to_le32(resource_id);
+
+	virtio_gpu_queue_fenced_ctrl_buffer(vgdev, vbuf, fence);
+}
+
 static void virtio_gpu_cmd_get_display_info_cb(struct virtio_gpu_device *vgdev,
 					       struct virtio_gpu_vbuffer *vbuf)
 {
@@ -1099,6 +1131,14 @@ void virtio_gpu_object_attach(struct virtio_gpu_device *vgdev,
 					       ents, nents, NULL);
 }
 
+void virtio_gpu_object_detach(struct virtio_gpu_device *vgdev,
+			      struct virtio_gpu_object *obj,
+			      struct virtio_gpu_fence *fence)
+{
+	virtio_gpu_cmd_resource_detach_backing(vgdev, obj->hw_res_handle,
+					       fence);
+}
+
 void virtio_gpu_cursor_ping(struct virtio_gpu_device *vgdev,
 			    struct virtio_gpu_output *output)
 {
diff --git a/include/uapi/drm/virtgpu_drm.h b/include/uapi/drm/virtgpu_drm.h
index 0512fde5e697..12197d8e9759 100644
--- a/include/uapi/drm/virtgpu_drm.h
+++ b/include/uapi/drm/virtgpu_drm.h
@@ -48,6 +48,7 @@ extern "C" {
 #define DRM_VIRTGPU_GET_CAPS  0x09
 #define DRM_VIRTGPU_RESOURCE_CREATE_BLOB 0x0a
 #define DRM_VIRTGPU_CONTEXT_INIT 0x0b
+#define DRM_VIRTGPU_MADVISE 0x0c
 
 #define VIRTGPU_EXECBUF_FENCE_FD_IN	0x01
 #define VIRTGPU_EXECBUF_FENCE_FD_OUT	0x02
@@ -196,6 +197,15 @@ struct drm_virtgpu_context_init {
 	__u64 ctx_set_params;
 };
 
+#define VIRTGPU_MADV_WILLNEED 0
+#define VIRTGPU_MADV_DONTNEED 1
+struct drm_virtgpu_madvise {
+	__u32 bo_handle;
+	__u32 retained; /* out, non-zero if BO can be used */
+	__u32 madv;
+	__u32 pad;
+};
+
 /*
  * Event code that's given when VIRTGPU_CONTEXT_PARAM_POLL_RINGS_MASK is in
  * effect.  The event size is sizeof(drm_event), since there is no additional
@@ -246,6 +256,10 @@ struct drm_virtgpu_context_init {
 	DRM_IOWR(DRM_COMMAND_BASE + DRM_VIRTGPU_CONTEXT_INIT,		\
 		struct drm_virtgpu_context_init)
 
+#define DRM_IOCTL_VIRTGPU_MADVISE \
+	DRM_IOWR(DRM_COMMAND_BASE + DRM_VIRTGPU_MADVISE, \
+		 struct drm_virtgpu_madvise)
+
 #if defined(__cplusplus)
 }
 #endif
-- 
2.35.1

[PATCH v5 14/17] drm/panfrost: Switch to generic memory shrinker

[Dmitry Osipenko]

Replace Panfrost's memory shrinker with a generic DRM SHMEM memory
shrinker.

Tested-by: Steven Price <steven.price@arm.com>
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
---
 drivers/gpu/drm/panfrost/Makefile             |   1 -
 drivers/gpu/drm/panfrost/panfrost_device.h    |   4 -
 drivers/gpu/drm/panfrost/panfrost_drv.c       |  19 +--
 drivers/gpu/drm/panfrost/panfrost_gem.c       |  28 ++--
 drivers/gpu/drm/panfrost/panfrost_gem.h       |   9 --
 .../gpu/drm/panfrost/panfrost_gem_shrinker.c  | 122 ------------------
 drivers/gpu/drm/panfrost/panfrost_job.c       |  18 ++-
 7 files changed, 37 insertions(+), 164 deletions(-)
 delete mode 100644 drivers/gpu/drm/panfrost/panfrost_gem_shrinker.c

diff --git a/drivers/gpu/drm/panfrost/Makefile b/drivers/gpu/drm/panfrost/Makefile
index b71935862417..ecf0864cb515 100644
--- a/drivers/gpu/drm/panfrost/Makefile
+++ b/drivers/gpu/drm/panfrost/Makefile
@@ -5,7 +5,6 @@ panfrost-y := \
 	panfrost_device.o \
 	panfrost_devfreq.o \
 	panfrost_gem.o \
-	panfrost_gem_shrinker.o \
 	panfrost_gpu.o \
 	panfrost_job.o \
 	panfrost_mmu.o \
diff --git a/drivers/gpu/drm/panfrost/panfrost_device.h b/drivers/gpu/drm/panfrost/panfrost_device.h
index 8b25278f34c8..fe04b21fc044 100644
--- a/drivers/gpu/drm/panfrost/panfrost_device.h
+++ b/drivers/gpu/drm/panfrost/panfrost_device.h
@@ -115,10 +115,6 @@ struct panfrost_device {
 		atomic_t pending;
 	} reset;
 
-	struct mutex shrinker_lock;
-	struct list_head shrinker_list;
-	struct shrinker shrinker;
-
 	struct panfrost_devfreq pfdevfreq;
 };
 
diff --git a/drivers/gpu/drm/panfrost/panfrost_drv.c b/drivers/gpu/drm/panfrost/panfrost_drv.c
index 7fcbc2a5b6cd..57a93555813f 100644
--- a/drivers/gpu/drm/panfrost/panfrost_drv.c
+++ b/drivers/gpu/drm/panfrost/panfrost_drv.c
@@ -160,7 +160,6 @@ panfrost_lookup_bos(struct drm_device *dev,
 			break;
 		}
 
-		atomic_inc(&bo->gpu_usecount);
 		job->mappings[i] = mapping;
 	}
 
@@ -391,7 +390,6 @@ static int panfrost_ioctl_madvise(struct drm_device *dev, void *data,
 {
 	struct panfrost_file_priv *priv = file_priv->driver_priv;
 	struct drm_panfrost_madvise *args = data;
-	struct panfrost_device *pfdev = dev->dev_private;
 	struct drm_gem_object *gem_obj;
 	struct panfrost_gem_object *bo;
 	int ret = 0;
@@ -404,7 +402,6 @@ static int panfrost_ioctl_madvise(struct drm_device *dev, void *data,
 
 	bo = to_panfrost_bo(gem_obj);
 
-	mutex_lock(&pfdev->shrinker_lock);
 	mutex_lock(&bo->mappings.lock);
 	if (args->madv == PANFROST_MADV_DONTNEED) {
 		struct panfrost_gem_mapping *first;
@@ -430,17 +427,8 @@ static int panfrost_ioctl_madvise(struct drm_device *dev, void *data,
 
 	args->retained = drm_gem_shmem_madvise(&bo->base, args->madv);
 
-	if (args->retained) {
-		if (args->madv == PANFROST_MADV_DONTNEED)
-			list_add_tail(&bo->base.madv_list,
-				      &pfdev->shrinker_list);
-		else if (args->madv == PANFROST_MADV_WILLNEED)
-			list_del_init(&bo->base.madv_list);
-	}
-
 out_unlock_mappings:
 	mutex_unlock(&bo->mappings.lock);
-	mutex_unlock(&pfdev->shrinker_lock);
 
 	drm_gem_object_put(gem_obj);
 	return ret;
@@ -571,9 +559,6 @@ static int panfrost_probe(struct platform_device *pdev)
 	ddev->dev_private = pfdev;
 	pfdev->ddev = ddev;
 
-	mutex_init(&pfdev->shrinker_lock);
-	INIT_LIST_HEAD(&pfdev->shrinker_list);
-
 	err = panfrost_device_init(pfdev);
 	if (err) {
 		if (err != -EPROBE_DEFER)
@@ -595,7 +580,7 @@ static int panfrost_probe(struct platform_device *pdev)
 	if (err < 0)
 		goto err_out1;
 
-	panfrost_gem_shrinker_init(ddev);
+	drm_gem_shmem_shrinker_register(ddev);
 
 	return 0;
 
@@ -613,8 +598,8 @@ static int panfrost_remove(struct platform_device *pdev)
 	struct panfrost_device *pfdev = platform_get_drvdata(pdev);
 	struct drm_device *ddev = pfdev->ddev;
 
+	drm_gem_shmem_shrinker_unregister(ddev);
 	drm_dev_unregister(ddev);
-	panfrost_gem_shrinker_cleanup(ddev);
 
 	pm_runtime_get_sync(pfdev->dev);
 	pm_runtime_disable(pfdev->dev);
diff --git a/drivers/gpu/drm/panfrost/panfrost_gem.c b/drivers/gpu/drm/panfrost/panfrost_gem.c
index 293e799e2fe8..f91ef0726e5e 100644
--- a/drivers/gpu/drm/panfrost/panfrost_gem.c
+++ b/drivers/gpu/drm/panfrost/panfrost_gem.c
@@ -19,16 +19,6 @@ static void panfrost_gem_free_object(struct drm_gem_object *obj)
 	struct panfrost_gem_object *bo = to_panfrost_bo(obj);
 	struct panfrost_device *pfdev = obj->dev->dev_private;
 
-	/*
-	 * Make sure the BO is no longer inserted in the shrinker list before
-	 * taking care of the destruction itself. If we don't do that we have a
-	 * race condition between this function and what's done in
-	 * panfrost_gem_shrinker_scan().
-	 */
-	mutex_lock(&pfdev->shrinker_lock);
-	list_del_init(&bo->base.madv_list);
-	mutex_unlock(&pfdev->shrinker_lock);
-
 	/*
 	 * If we still have mappings attached to the BO, there's a problem in
 	 * our refcounting.
@@ -209,6 +199,20 @@ static const struct drm_gem_object_funcs panfrost_gem_funcs = {
 	.vm_ops = &drm_gem_shmem_vm_ops,
 };
 
+static int panfrost_shmem_purge(struct drm_gem_shmem_object *shmem)
+{
+	struct panfrost_gem_object *bo = to_panfrost_bo(&shmem->base);
+
+	if (!mutex_trylock(&bo->mappings.lock))
+		return -EBUSY;
+
+	panfrost_gem_teardown_mappings_locked(bo);
+
+	mutex_unlock(&bo->mappings.lock);
+
+	return 0;
+}
+
 /**
  * panfrost_gem_create_object - Implementation of driver->gem_create_object.
  * @dev: DRM device
@@ -230,6 +234,7 @@ struct drm_gem_object *panfrost_gem_create_object(struct drm_device *dev, size_t
 	mutex_init(&obj->mappings.lock);
 	obj->base.base.funcs = &panfrost_gem_funcs;
 	obj->base.map_wc = !pfdev->coherent;
+	obj->base.purge = panfrost_shmem_purge;
 
 	return &obj->base.base;
 }
@@ -266,6 +271,9 @@ panfrost_gem_create_with_handle(struct drm_file *file_priv,
 	if (ret)
 		return ERR_PTR(ret);
 
+	if (!bo->is_heap)
+		drm_gem_shmem_set_purgeable(shmem);
+
 	return bo;
 }
 
diff --git a/drivers/gpu/drm/panfrost/panfrost_gem.h b/drivers/gpu/drm/panfrost/panfrost_gem.h
index 8088d5fd8480..09da064f1c07 100644
--- a/drivers/gpu/drm/panfrost/panfrost_gem.h
+++ b/drivers/gpu/drm/panfrost/panfrost_gem.h
@@ -30,12 +30,6 @@ struct panfrost_gem_object {
 		struct mutex lock;
 	} mappings;
 
-	/*
-	 * Count the number of jobs referencing this BO so we don't let the
-	 * shrinker reclaim this object prematurely.
-	 */
-	atomic_t gpu_usecount;
-
 	bool noexec		:1;
 	bool is_heap		:1;
 };
@@ -84,7 +78,4 @@ panfrost_gem_mapping_get(struct panfrost_gem_object *bo,
 void panfrost_gem_mapping_put(struct panfrost_gem_mapping *mapping);
 void panfrost_gem_teardown_mappings_locked(struct panfrost_gem_object *bo);
 
-void panfrost_gem_shrinker_init(struct drm_device *dev);
-void panfrost_gem_shrinker_cleanup(struct drm_device *dev);
-
 #endif /* __PANFROST_GEM_H__ */
diff --git a/drivers/gpu/drm/panfrost/panfrost_gem_shrinker.c b/drivers/gpu/drm/panfrost/panfrost_gem_shrinker.c
deleted file mode 100644
index 3bcf8c291866..000000000000
--- a/drivers/gpu/drm/panfrost/panfrost_gem_shrinker.c
+++ /dev/null
@@ -1,122 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/* Copyright (C) 2019 Arm Ltd.
- *
- * Based on msm_gem_freedreno.c:
- * Copyright (C) 2016 Red Hat
- * Author: Rob Clark <robdclark@gmail.com>
- */
-
-#include <linux/list.h>
-
-#include <drm/drm_device.h>
-#include <drm/drm_gem_shmem_helper.h>
-
-#include "panfrost_device.h"
-#include "panfrost_gem.h"
-#include "panfrost_mmu.h"
-
-static unsigned long
-panfrost_gem_shrinker_count(struct shrinker *shrinker, struct shrink_control *sc)
-{
-	struct panfrost_device *pfdev =
-		container_of(shrinker, struct panfrost_device, shrinker);
-	struct drm_gem_shmem_object *shmem;
-	unsigned long count = 0;
-
-	if (!mutex_trylock(&pfdev->shrinker_lock))
-		return 0;
-
-	list_for_each_entry(shmem, &pfdev->shrinker_list, madv_list) {
-		if (drm_gem_shmem_is_purgeable(shmem))
-			count += shmem->base.size >> PAGE_SHIFT;
-	}
-
-	mutex_unlock(&pfdev->shrinker_lock);
-
-	return count;
-}
-
-static bool panfrost_gem_purge(struct drm_gem_object *obj)
-{
-	struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj);
-	struct panfrost_gem_object *bo = to_panfrost_bo(obj);
-	bool ret = false;
-
-	if (atomic_read(&bo->gpu_usecount))
-		return false;
-
-	if (!mutex_trylock(&bo->mappings.lock))
-		return false;
-
-	if (!dma_resv_trylock(shmem->base.resv))
-		goto unlock_mappings;
-
-	panfrost_gem_teardown_mappings_locked(bo);
-	drm_gem_shmem_purge_locked(&bo->base);
-	ret = true;
-
-	dma_resv_unlock(shmem->base.resv);
-
-unlock_mappings:
-	mutex_unlock(&bo->mappings.lock);
-	return ret;
-}
-
-static unsigned long
-panfrost_gem_shrinker_scan(struct shrinker *shrinker, struct shrink_control *sc)
-{
-	struct panfrost_device *pfdev =
-		container_of(shrinker, struct panfrost_device, shrinker);
-	struct drm_gem_shmem_object *shmem, *tmp;
-	unsigned long freed = 0;
-
-	if (!mutex_trylock(&pfdev->shrinker_lock))
-		return SHRINK_STOP;
-
-	list_for_each_entry_safe(shmem, tmp, &pfdev->shrinker_list, madv_list) {
-		if (freed >= sc->nr_to_scan)
-			break;
-		if (drm_gem_shmem_is_purgeable(shmem) &&
-		    panfrost_gem_purge(&shmem->base)) {
-			freed += shmem->base.size >> PAGE_SHIFT;
-			list_del_init(&shmem->madv_list);
-		}
-	}
-
-	mutex_unlock(&pfdev->shrinker_lock);
-
-	if (freed > 0)
-		pr_info_ratelimited("Purging %lu bytes\n", freed << PAGE_SHIFT);
-
-	return freed;
-}
-
-/**
- * panfrost_gem_shrinker_init - Initialize panfrost shrinker
- * @dev: DRM device
- *
- * This function registers and sets up the panfrost shrinker.
- */
-void panfrost_gem_shrinker_init(struct drm_device *dev)
-{
-	struct panfrost_device *pfdev = dev->dev_private;
-	pfdev->shrinker.count_objects = panfrost_gem_shrinker_count;
-	pfdev->shrinker.scan_objects = panfrost_gem_shrinker_scan;
-	pfdev->shrinker.seeks = DEFAULT_SEEKS;
-	WARN_ON(register_shrinker(&pfdev->shrinker));
-}
-
-/**
- * panfrost_gem_shrinker_cleanup - Clean up panfrost shrinker
- * @dev: DRM device
- *
- * This function unregisters the panfrost shrinker.
- */
-void panfrost_gem_shrinker_cleanup(struct drm_device *dev)
-{
-	struct panfrost_device *pfdev = dev->dev_private;
-
-	if (pfdev->shrinker.nr_deferred) {
-		unregister_shrinker(&pfdev->shrinker);
-	}
-}
diff --git a/drivers/gpu/drm/panfrost/panfrost_job.c b/drivers/gpu/drm/panfrost/panfrost_job.c
index fda5871aebe3..bcf496b837ce 100644
--- a/drivers/gpu/drm/panfrost/panfrost_job.c
+++ b/drivers/gpu/drm/panfrost/panfrost_job.c
@@ -271,6 +271,19 @@ static void panfrost_attach_object_fences(struct drm_gem_object **bos,
 		dma_resv_add_fence(bos[i]->resv, fence, DMA_RESV_USAGE_WRITE);
 }
 
+static int panfrost_objects_prepare(struct drm_gem_object **bos, int bo_count)
+{
+	struct panfrost_gem_object *bo;
+	int ret = 0;
+
+	while (!ret && bo_count--) {
+		bo = to_panfrost_bo(bos[bo_count]);
+		ret = bo->base.madv ? -ENOMEM : 0;
+	}
+
+	return ret;
+}
+
 int panfrost_job_push(struct panfrost_job *job)
 {
 	struct panfrost_device *pfdev = job->pfdev;
@@ -282,6 +295,10 @@ int panfrost_job_push(struct panfrost_job *job)
 	if (ret)
 		return ret;
 
+	ret = panfrost_objects_prepare(job->bos, job->bo_count);
+	if (ret)
+		goto unlock;
+
 	mutex_lock(&pfdev->sched_lock);
 	drm_sched_job_arm(&job->base);
 
@@ -323,7 +340,6 @@ static void panfrost_job_cleanup(struct kref *ref)
 			if (!job->mappings[i])
 				break;
 
-			atomic_dec(&job->mappings[i]->obj->gpu_usecount);
 			panfrost_gem_mapping_put(job->mappings[i]);
 		}
 		kvfree(job->mappings);
-- 
2.35.1

[PATCH v5 15/17] drm/shmem-helper: Make drm_gem_shmem_get_pages() private

[Dmitry Osipenko]

VirtIO-GPU driver was the only user of drm_gem_shmem_get_pages()
and it now uses drm_gem_shmem_get_pages_sgt(). Make the get_pages()
private to drm_gem_shmem_helper.

Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
---
 drivers/gpu/drm/drm_gem_shmem_helper.c | 3 +--
 include/drm/drm_gem_shmem_helper.h     | 1 -
 2 files changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c
index 25e9bc2803ee..7ec5f8002f68 100644
--- a/drivers/gpu/drm/drm_gem_shmem_helper.c
+++ b/drivers/gpu/drm/drm_gem_shmem_helper.c
@@ -490,7 +490,7 @@ static int drm_gem_shmem_get_pages_locked(struct drm_gem_shmem_object *shmem)
  * Returns:
  * 0 on success or a negative error code on failure.
  */
-int drm_gem_shmem_get_pages(struct drm_gem_shmem_object *shmem)
+static int drm_gem_shmem_get_pages(struct drm_gem_shmem_object *shmem)
 {
 	int ret;
 
@@ -507,7 +507,6 @@ int drm_gem_shmem_get_pages(struct drm_gem_shmem_object *shmem)
 
 	return ret;
 }
-EXPORT_SYMBOL(drm_gem_shmem_get_pages);
 
 static void drm_gem_shmem_get_pages_no_fail(struct drm_gem_shmem_object *shmem)
 {
diff --git a/include/drm/drm_gem_shmem_helper.h b/include/drm/drm_gem_shmem_helper.h
index 638cb16a4576..5b351933c293 100644
--- a/include/drm/drm_gem_shmem_helper.h
+++ b/include/drm/drm_gem_shmem_helper.h
@@ -180,7 +180,6 @@ struct drm_gem_shmem_object {
 struct drm_gem_shmem_object *drm_gem_shmem_create(struct drm_device *dev, size_t size);
 void drm_gem_shmem_free(struct drm_gem_shmem_object *shmem);
 
-int drm_gem_shmem_get_pages(struct drm_gem_shmem_object *shmem);
 void drm_gem_shmem_put_pages(struct drm_gem_shmem_object *shmem);
 int drm_gem_shmem_pin(struct drm_gem_shmem_object *shmem);
 void drm_gem_shmem_unpin(struct drm_gem_shmem_object *shmem);
-- 
2.35.1

[PATCH v5 16/17] drm/shmem-helper: Make drm_gem_shmem_is_purgeable() private

[Dmitry Osipenko]

Panfrost driver was the only user of the drm_gem_shmem_is_purgeable()
helper. Panfrost driver was converted to use new generic memory shrinker
and the helper doesn't have external users anymore, hence make it private
to the drm_gem_shmem_helper.c to keep the code clean.

Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
---
 drivers/gpu/drm/drm_gem_shmem_helper.c | 9 ++++++++-
 include/drm/drm_gem_shmem_helper.h     | 7 -------
 2 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c
index 7ec5f8002f68..045921ad4795 100644
--- a/drivers/gpu/drm/drm_gem_shmem_helper.c
+++ b/drivers/gpu/drm/drm_gem_shmem_helper.c
@@ -169,6 +169,13 @@ static bool drm_gem_shmem_is_evictable(struct drm_gem_shmem_object *shmem)
 		!shmem->base.import_attach && shmem->sgt && !shmem->evicted;
 }
 
+static bool drm_gem_shmem_is_purgeable(struct drm_gem_shmem_object *shmem)
+{
+	return (shmem->madv > 0) && !shmem->purge_disable_count &&
+		!shmem->vmap_use_count && !shmem->base.dma_buf &&
+		!shmem->base.import_attach && shmem->sgt;
+}
+
 static void
 drm_gem_shmem_update_pages_state_locked(struct drm_gem_shmem_object *shmem)
 {
@@ -182,7 +189,7 @@ drm_gem_shmem_update_pages_state_locked(struct drm_gem_shmem_object *shmem)
 
 	mutex_lock(&gem_shrinker->lock);
 
-	if (drm_gem_shmem_is_purgeable(shmem) && !shmem->purge_disable_count) {
+	if (drm_gem_shmem_is_purgeable(shmem)) {
 		drm_gem_shmem_add_pages_to_shrinker(shmem);
 		list_move_tail(&shmem->madv_list, &gem_shrinker->lru_purgeable);
 	} else if (drm_gem_shmem_is_evictable(shmem)) {
diff --git a/include/drm/drm_gem_shmem_helper.h b/include/drm/drm_gem_shmem_helper.h
index 5b351933c293..972687bf9717 100644
--- a/include/drm/drm_gem_shmem_helper.h
+++ b/include/drm/drm_gem_shmem_helper.h
@@ -194,13 +194,6 @@ int drm_gem_shmem_madvise(struct drm_gem_shmem_object *shmem, int madv);
 int drm_gem_shmem_set_purgeable(struct drm_gem_shmem_object *shmem);
 int drm_gem_shmem_set_purgeable_and_evictable(struct drm_gem_shmem_object *shmem);
 
-static inline bool drm_gem_shmem_is_purgeable(struct drm_gem_shmem_object *shmem)
-{
-	return (shmem->madv > 0) &&
-		!shmem->vmap_use_count && shmem->sgt &&
-		!shmem->base.dma_buf && !shmem->base.import_attach;
-}
-
 int drm_gem_shmem_swap_in_locked(struct drm_gem_shmem_object *shmem);
 void drm_gem_shmem_purge_locked(struct drm_gem_shmem_object *shmem);
 
-- 
2.35.1

[PATCH v5 17/17] drm/shmem-helper: Remove drm_gem_shmem_purge_locked()

[Dmitry Osipenko]

Panfrost driver was the only user of the drm_gem_shmem_purge_locked()
helper. Panfrost driver was converted to use new generic memory shrinker
and the helper doesn't have users anymore, remove it.

Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
---
 drivers/gpu/drm/drm_gem_shmem_helper.c | 30 --------------------------
 include/drm/drm_gem_shmem_helper.h     |  1 -
 2 files changed, 31 deletions(-)

diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c
index 045921ad4795..ef7691c84fa8 100644
--- a/drivers/gpu/drm/drm_gem_shmem_helper.c
+++ b/drivers/gpu/drm/drm_gem_shmem_helper.c
@@ -899,36 +899,6 @@ static void drm_gem_shmem_unpin_pages_locked(struct drm_gem_shmem_object *shmem)
 	shmem->sgt = NULL;
 }
 
-void drm_gem_shmem_purge_locked(struct drm_gem_shmem_object *shmem)
-{
-	struct drm_gem_object *obj = &shmem->base;
-	struct drm_device *dev = obj->dev;
-
-	WARN_ON(!drm_gem_shmem_is_purgeable(shmem));
-
-	dma_unmap_sgtable(dev->dev, shmem->sgt, DMA_BIDIRECTIONAL, 0);
-	sg_free_table(shmem->sgt);
-	kfree(shmem->sgt);
-	shmem->sgt = NULL;
-
-	drm_gem_shmem_put_pages_locked(shmem);
-
-	shmem->madv = -1;
-
-	drm_vma_node_unmap(&obj->vma_node, dev->anon_inode->i_mapping);
-	drm_gem_free_mmap_offset(obj);
-
-	/* Our goal here is to return as much of the memory as
-	 * is possible back to the system as we are called from OOM.
-	 * To do this we must instruct the shmfs to drop all of its
-	 * backing pages, *now*.
-	 */
-	shmem_truncate_range(file_inode(obj->filp), 0, (loff_t)-1);
-
-	invalidate_mapping_pages(file_inode(obj->filp)->i_mapping, 0, (loff_t)-1);
-}
-EXPORT_SYMBOL(drm_gem_shmem_purge_locked);
-
 /**
  * drm_gem_shmem_dumb_create - Create a dumb shmem buffer object
  * @file: DRM file structure to create the dumb buffer for
diff --git a/include/drm/drm_gem_shmem_helper.h b/include/drm/drm_gem_shmem_helper.h
index 972687bf9717..8d7053c36fa6 100644
--- a/include/drm/drm_gem_shmem_helper.h
+++ b/include/drm/drm_gem_shmem_helper.h
@@ -195,7 +195,6 @@ int drm_gem_shmem_set_purgeable(struct drm_gem_shmem_object *shmem);
 int drm_gem_shmem_set_purgeable_and_evictable(struct drm_gem_shmem_object *shmem);
 
 int drm_gem_shmem_swap_in_locked(struct drm_gem_shmem_object *shmem);
-void drm_gem_shmem_purge_locked(struct drm_gem_shmem_object *shmem);
 
 struct sg_table *drm_gem_shmem_get_sg_table(struct drm_gem_shmem_object *shmem);
 struct sg_table *drm_gem_shmem_get_pages_sgt(struct drm_gem_shmem_object *shmem);
-- 
2.35.1

Re: [PATCH v5 15/17] drm/shmem-helper: Make drm_gem_shmem_get_pages() private

[Daniel Vetter]

On Sun, Apr 24, 2022 at 10:04:22PM +0300, Dmitry Osipenko wrote:
> VirtIO-GPU driver was the only user of drm_gem_shmem_get_pages()
> and it now uses drm_gem_shmem_get_pages_sgt(). Make the get_pages()
> private to drm_gem_shmem_helper.
> 
> Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
> ---
>  drivers/gpu/drm/drm_gem_shmem_helper.c | 3 +--
>  include/drm/drm_gem_shmem_helper.h     | 1 -
>  2 files changed, 1 insertion(+), 3 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c
> index 25e9bc2803ee..7ec5f8002f68 100644
> --- a/drivers/gpu/drm/drm_gem_shmem_helper.c
> +++ b/drivers/gpu/drm/drm_gem_shmem_helper.c
> @@ -490,7 +490,7 @@ static int drm_gem_shmem_get_pages_locked(struct drm_gem_shmem_object *shmem)
>   * Returns:
>   * 0 on success or a negative error code on failure.
>   */

We also delete the kerneldoc for functions not exported (kerneldoc is
geared towards driver writes). If there's anything critical the comment
explains about the internals, you can keep that as a normal C style
comment without the /** but generally there's no need for these anymore.
-Daniel

> -int drm_gem_shmem_get_pages(struct drm_gem_shmem_object *shmem)
> +static int drm_gem_shmem_get_pages(struct drm_gem_shmem_object *shmem)
>  {
>  	int ret;
>  
> @@ -507,7 +507,6 @@ int drm_gem_shmem_get_pages(struct drm_gem_shmem_object *shmem)
>  
>  	return ret;
>  }
> -EXPORT_SYMBOL(drm_gem_shmem_get_pages);
>  
>  static void drm_gem_shmem_get_pages_no_fail(struct drm_gem_shmem_object *shmem)
>  {
> diff --git a/include/drm/drm_gem_shmem_helper.h b/include/drm/drm_gem_shmem_helper.h
> index 638cb16a4576..5b351933c293 100644
> --- a/include/drm/drm_gem_shmem_helper.h
> +++ b/include/drm/drm_gem_shmem_helper.h
> @@ -180,7 +180,6 @@ struct drm_gem_shmem_object {
>  struct drm_gem_shmem_object *drm_gem_shmem_create(struct drm_device *dev, size_t size);
>  void drm_gem_shmem_free(struct drm_gem_shmem_object *shmem);
>  
> -int drm_gem_shmem_get_pages(struct drm_gem_shmem_object *shmem);
>  void drm_gem_shmem_put_pages(struct drm_gem_shmem_object *shmem);
>  int drm_gem_shmem_pin(struct drm_gem_shmem_object *shmem);
>  void drm_gem_shmem_unpin(struct drm_gem_shmem_object *shmem);
> -- 
> 2.35.1
> 

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch

Re: [PATCH v5 01/17] drm/panfrost: Put mapping instead of shmem obj on panfrost_mmu_map_fault_addr() error

[Steven Price]

On 24/04/2022 20:04, Dmitry Osipenko wrote:
> When panfrost_mmu_map_fault_addr() fails, the BO's mapping should be
> unreferenced and not the shmem object that backs that mapping.
> 
> Cc: stable@vger.kernel.org
> Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>

Fixes: bdefca2d8dc0 ("drm/panfrost: Add the panfrost_gem_mapping concept")

Reviewed-by: Steven Price <steven.price@arm.com>

Thanks,

Steve

> ---
>  drivers/gpu/drm/panfrost/panfrost_mmu.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/panfrost/panfrost_mmu.c b/drivers/gpu/drm/panfrost/panfrost_mmu.c
> index d3f82b26a631..b285a8001b1d 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_mmu.c
> +++ b/drivers/gpu/drm/panfrost/panfrost_mmu.c
> @@ -518,7 +518,7 @@ static int panfrost_mmu_map_fault_addr(struct panfrost_device *pfdev, int as,
>  err_pages:
>  	drm_gem_shmem_put_pages(&bo->base);
>  err_bo:
> -	drm_gem_object_put(&bo->base.base);
> +	panfrost_gem_mapping_put(bomapping);
>  	return ret;
>  }
>  

Re: [PATCH v5 15/17] drm/shmem-helper: Make drm_gem_shmem_get_pages() private

[Dmitry Osipenko]

28.04.2022 15:33, Daniel Vetter пишет:
> On Sun, Apr 24, 2022 at 10:04:22PM +0300, Dmitry Osipenko wrote:
>> VirtIO-GPU driver was the only user of drm_gem_shmem_get_pages()
>> and it now uses drm_gem_shmem_get_pages_sgt(). Make the get_pages()
>> private to drm_gem_shmem_helper.
>>
>> Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
>> ---
>>  drivers/gpu/drm/drm_gem_shmem_helper.c | 3 +--
>>  include/drm/drm_gem_shmem_helper.h     | 1 -
>>  2 files changed, 1 insertion(+), 3 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c
>> index 25e9bc2803ee..7ec5f8002f68 100644
>> --- a/drivers/gpu/drm/drm_gem_shmem_helper.c
>> +++ b/drivers/gpu/drm/drm_gem_shmem_helper.c
>> @@ -490,7 +490,7 @@ static int drm_gem_shmem_get_pages_locked(struct drm_gem_shmem_object *shmem)
>>   * Returns:
>>   * 0 on success or a negative error code on failure.
>>   */
> 
> We also delete the kerneldoc for functions not exported (kerneldoc is
> geared towards driver writes). If there's anything critical the comment
> explains about the internals, you can keep that as a normal C style
> comment without the /** but generally there's no need for these anymore.

Noted for v6.

Re: [PATCH v5 01/17] drm/panfrost: Put mapping instead of shmem obj on panfrost_mmu_map_fault_addr() error

[Dmitry Osipenko]

28.04.2022 16:19, Steven Price пишет:
> On 24/04/2022 20:04, Dmitry Osipenko wrote:
>> When panfrost_mmu_map_fault_addr() fails, the BO's mapping should be
>> unreferenced and not the shmem object that backs that mapping.
>>
>> Cc: stable@vger.kernel.org
>> Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
> 
> Fixes: bdefca2d8dc0 ("drm/panfrost: Add the panfrost_gem_mapping concept")
> 
> Reviewed-by: Steven Price <steven.price@arm.com>

Thank you for the fixes tag. It appeared to me that this problem existed
since the first addition of the srinker when I was looking up the
offending commit, my bad :)