[PATCH v11 00/10] Add generic memory shrinker to VirtIO-GPU and Panfrost DRM drivers

[PATCH v11 00/10] Add generic memory shrinker to VirtIO-GPU and Panfrost DRM drivers

[Dmitry Osipenko]

This series:

  1. Adds common drm-shmem memory shrinker
  2. Enables shrinker for VirtIO-GPU driver
  3. Switches Panfrost driver to the common shrinker

Changelog:

v11:- Rebased on a recent linux-next. Added new patch as a result:

        drm/shmem-helper: Export drm_gem_shmem_get_pages_sgt_locked()

        It's needed by the virtio-gpu driver to swap-in/unevict shmem
        object, previously get_pages_sgt() didn't use locking.

    - Separated the "Add memory shrinker" patch into smaller parts to ease
      the reviewing, as was requested by Thomas Zimmermann:

        drm/shmem-helper: Factor out pages alloc/release from
          drm_gem_shmem_get/put_pages()
        drm/shmem-helper: Add pages_pin_count field
        drm/shmem-helper: Switch drm_gem_shmem_vmap/vunmap to use pin/unpin
        drm/shmem-helper: Factor out unpinning part from drm_gem_shmem_purge()

    - Addessed the v10 review comments from Thomas Zimmermann: return errno
      instead of bool, sort code alphabetically, rename function and etc
      minor changes.

    - Added new patch to remove the "map->is_iomem" from drm-shmem, as
      was suggested by Thomas Zimmermann.

    - Added acks and r-b's that were given to v10.

v10:- Was partially applied to misc-fixes/next.

      https://lore.kernel.org/dri-devel/6c16f303-81df-7ebe-85e9-51bb40a8b301@collabora.com/T/

Dmitry Osipenko (10):
  drm/shmem-helper: Factor out pages alloc/release from
    drm_gem_shmem_get/put_pages()
  drm/shmem-helper: Add pages_pin_count field
  drm/shmem-helper: Switch drm_gem_shmem_vmap/vunmap to use pin/unpin
  drm/shmem-helper: Factor out unpinning part from drm_gem_shmem_purge()
  drm/shmem-helper: Add memory shrinker
  drm/shmem-helper: Remove obsoleted is_iomem test
  drm/shmem-helper: Export drm_gem_shmem_get_pages_sgt_locked()
  drm/gem: Add drm_gem_pin_unlocked()
  drm/virtio: Support memory shrinking
  drm/panfrost: Switch to generic memory shrinker

 drivers/gpu/drm/drm_gem.c                     |  29 ++
 drivers/gpu/drm/drm_gem_shmem_helper.c        | 453 ++++++++++++++++--
 drivers/gpu/drm/panfrost/Makefile             |   1 -
 drivers/gpu/drm/panfrost/panfrost_device.h    |   4 -
 drivers/gpu/drm/panfrost/panfrost_drv.c       |  27 +-
 drivers/gpu/drm/panfrost/panfrost_gem.c       |  30 +-
 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/virtio/virtgpu_drv.h          |  18 +-
 drivers/gpu/drm/virtio/virtgpu_gem.c          |  52 ++
 drivers/gpu/drm/virtio/virtgpu_ioctl.c        |  37 ++
 drivers/gpu/drm/virtio/virtgpu_kms.c          |   8 +
 drivers/gpu/drm/virtio/virtgpu_object.c       | 137 ++++--
 drivers/gpu/drm/virtio/virtgpu_plane.c        |  22 +-
 drivers/gpu/drm/virtio/virtgpu_vq.c           |  40 ++
 include/drm/drm_device.h                      |  10 +-
 include/drm/drm_gem.h                         |   3 +
 include/drm/drm_gem_shmem_helper.h            |  69 ++-
 include/uapi/drm/virtgpu_drm.h                |  14 +
 20 files changed, 857 insertions(+), 246 deletions(-)
 delete mode 100644 drivers/gpu/drm/panfrost/panfrost_gem_shrinker.c

-- 
2.39.2

[PATCH v11 01/10] drm/shmem-helper: Factor out pages alloc/release from drm_gem_shmem_get/put_pages()

[Dmitry Osipenko]

Factor out pages allocation from drm_gem_shmem_get_pages() into
drm_gem_shmem_acquire_pages() function and similar for the put_pages()
in a preparation for addition of shrinker support to drm-shmem.

Once shrinker will be added, the pages_use_count>0 will no longer determine
whether pages are pinned because pages could be swapped out by the shrinker
and then pages_use_count will be greater than 0 in this case. We will add
new pages_pin_count in a later patch.

The new common drm_gem_shmem_acquire/release_pages() will be used by
shrinker code for performing the page swapping.

Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
---
 drivers/gpu/drm/drm_gem_shmem_helper.c | 67 +++++++++++++++++++++-----
 1 file changed, 54 insertions(+), 13 deletions(-)

diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c
index ad01c43ff26e..49ab49454783 100644
--- a/drivers/gpu/drm/drm_gem_shmem_helper.c
+++ b/drivers/gpu/drm/drm_gem_shmem_helper.c
@@ -165,19 +165,26 @@ 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(struct drm_gem_shmem_object *shmem)
+static int
+drm_gem_shmem_acquire_pages(struct drm_gem_shmem_object *shmem)
 {
 	struct drm_gem_object *obj = &shmem->base;
 	struct page **pages;
 
-	if (shmem->pages_use_count++ > 0)
-		return 0;
+	dma_resv_assert_held(shmem->base.resv);
+
+	if (shmem->madv < 0) {
+		drm_WARN_ON(obj->dev, shmem->pages);
+		return -ENOMEM;
+	}
+
+	if (drm_WARN_ON(obj->dev, !shmem->pages_use_count))
+		return -EINVAL;
 
 	pages = drm_gem_get_pages(obj);
 	if (IS_ERR(pages)) {
 		drm_dbg_kms(obj->dev, "Failed to get pages (%ld)\n",
 			    PTR_ERR(pages));
-		shmem->pages_use_count = 0;
 		return PTR_ERR(pages);
 	}
 
@@ -196,6 +203,48 @@ static int drm_gem_shmem_get_pages(struct drm_gem_shmem_object *shmem)
 	return 0;
 }
 
+static int drm_gem_shmem_get_pages(struct drm_gem_shmem_object *shmem)
+{
+	int err;
+
+	dma_resv_assert_held(shmem->base.resv);
+
+	if (shmem->madv < 0)
+		return -ENOMEM;
+
+	if (shmem->pages_use_count++ > 0)
+		return 0;
+
+	err = drm_gem_shmem_acquire_pages(shmem);
+	if (err)
+		goto err_zero_use;
+
+	return 0;
+
+err_zero_use:
+	shmem->pages_use_count = 0;
+
+	return err;
+}
+
+static void
+drm_gem_shmem_release_pages(struct drm_gem_shmem_object *shmem)
+{
+	struct drm_gem_object *obj = &shmem->base;
+
+	dma_resv_assert_held(shmem->base.resv);
+
+#ifdef CONFIG_X86
+	if (shmem->map_wc)
+		set_pages_array_wb(shmem->pages, obj->size >> PAGE_SHIFT);
+#endif
+
+	drm_gem_put_pages(obj, shmem->pages,
+			  shmem->pages_mark_dirty_on_put,
+			  shmem->pages_mark_accessed_on_put);
+	shmem->pages = NULL;
+}
+
 /*
  * drm_gem_shmem_put_pages - Decrease use count on the backing pages for a shmem GEM object
  * @shmem: shmem GEM object
@@ -214,15 +263,7 @@ void drm_gem_shmem_put_pages(struct drm_gem_shmem_object *shmem)
 	if (--shmem->pages_use_count > 0)
 		return;
 
-#ifdef CONFIG_X86
-	if (shmem->map_wc)
-		set_pages_array_wb(shmem->pages, obj->size >> PAGE_SHIFT);
-#endif
-
-	drm_gem_put_pages(obj, shmem->pages,
-			  shmem->pages_mark_dirty_on_put,
-			  shmem->pages_mark_accessed_on_put);
-	shmem->pages = NULL;
+	drm_gem_shmem_release_pages(shmem);
 }
 EXPORT_SYMBOL(drm_gem_shmem_put_pages);
 
-- 
2.39.2

[PATCH v11 02/10] drm/shmem-helper: Add pages_pin_count field

[Dmitry Osipenko]

And new pages_pin_count field to struct drm_gem_shmem_object that will
determine whether pages are evictable by memory shrinker. The pages will
be evictable only when pages_pin_count=0. This patch prepares code for
addition of the memory shrinker that will utilize the new field.

Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
---
 drivers/gpu/drm/drm_gem_shmem_helper.c | 12 +++++++++++-
 include/drm/drm_gem_shmem_helper.h     |  9 +++++++++
 2 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c
index 49ab49454783..97b40676bdfa 100644
--- a/drivers/gpu/drm/drm_gem_shmem_helper.c
+++ b/drivers/gpu/drm/drm_gem_shmem_helper.c
@@ -280,12 +280,17 @@ EXPORT_SYMBOL(drm_gem_shmem_put_pages);
 int drm_gem_shmem_pin(struct drm_gem_shmem_object *shmem)
 {
 	struct drm_gem_object *obj = &shmem->base;
+	int ret;
 
 	dma_resv_assert_held(shmem->base.resv);
 
 	drm_WARN_ON(obj->dev, obj->import_attach);
 
-	return drm_gem_shmem_get_pages(shmem);
+	ret = drm_gem_shmem_get_pages(shmem);
+	if (!ret)
+		shmem->pages_pin_count++;
+
+	return ret;
 }
 EXPORT_SYMBOL(drm_gem_shmem_pin);
 
@@ -304,7 +309,12 @@ void drm_gem_shmem_unpin(struct drm_gem_shmem_object *shmem)
 
 	drm_WARN_ON(obj->dev, obj->import_attach);
 
+	if (drm_WARN_ON_ONCE(obj->dev, !shmem->pages_pin_count))
+		return;
+
 	drm_gem_shmem_put_pages(shmem);
+
+	shmem->pages_pin_count--;
 }
 EXPORT_SYMBOL(drm_gem_shmem_unpin);
 
diff --git a/include/drm/drm_gem_shmem_helper.h b/include/drm/drm_gem_shmem_helper.h
index 20ddcd799df9..7d823c9fc480 100644
--- a/include/drm/drm_gem_shmem_helper.h
+++ b/include/drm/drm_gem_shmem_helper.h
@@ -39,6 +39,15 @@ struct drm_gem_shmem_object {
 	 */
 	unsigned int pages_use_count;
 
+	/**
+	 * @pages_pin_count:
+	 *
+	 * Reference count on the pinned pages table.
+	 * The pages allowed to be evicted by memory shrinker
+	 * only when the count is zero.
+	 */
+	unsigned int pages_pin_count;
+
 	/**
 	 * @madv: State for madvise
 	 *
-- 
2.39.2

[PATCH v11 03/10] drm/shmem-helper: Switch drm_gem_shmem_vmap/vunmap to use pin/unpin

[Dmitry Osipenko]

The vmapped pages shall be pinned in memory. Previously get/put pages were
implicitly pinning/unpinning the pages. This will no longer be the case
with addition of memory shrinker because pages_use_count>0 won't determine
whether pages are pinned anymore, while the new pages_pin_count will do
that. Switch the vmap/vunmap to use pin/unpin functions in a preparation
of addition of the memory shrinker support.

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

diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c
index 97b40676bdfa..2b1eef335bf6 100644
--- a/drivers/gpu/drm/drm_gem_shmem_helper.c
+++ b/drivers/gpu/drm/drm_gem_shmem_helper.c
@@ -357,7 +357,7 @@ int drm_gem_shmem_vmap(struct drm_gem_shmem_object *shmem,
 			return 0;
 		}
 
-		ret = drm_gem_shmem_get_pages(shmem);
+		ret = drm_gem_shmem_pin(shmem);
 		if (ret)
 			goto err_zero_use;
 
@@ -380,7 +380,7 @@ int drm_gem_shmem_vmap(struct drm_gem_shmem_object *shmem,
 
 err_put_pages:
 	if (!obj->import_attach)
-		drm_gem_shmem_put_pages(shmem);
+		drm_gem_shmem_unpin(shmem);
 err_zero_use:
 	shmem->vmap_use_count = 0;
 
@@ -417,7 +417,7 @@ void drm_gem_shmem_vunmap(struct drm_gem_shmem_object *shmem,
 			return;
 
 		vunmap(shmem->vaddr);
-		drm_gem_shmem_put_pages(shmem);
+		drm_gem_shmem_unpin(shmem);
 	}
 
 	shmem->vaddr = NULL;
-- 
2.39.2

[PATCH v11 04/10] drm/shmem-helper: Factor out unpinning part from drm_gem_shmem_purge()

[Dmitry Osipenko]

Factor out pages unpinning code from drm_gem_shmem_purge() into new
drm_gem_shmem_unpin_pages(). This prepares code for addition of memory
shrinker support. The new common function will be used by shrinker for
eviction of shmem pages.

Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
---
 drivers/gpu/drm/drm_gem_shmem_helper.c | 18 ++++++++++++------
 1 file changed, 12 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c
index 2b1eef335bf6..fc1cfd5f5e7a 100644
--- a/drivers/gpu/drm/drm_gem_shmem_helper.c
+++ b/drivers/gpu/drm/drm_gem_shmem_helper.c
@@ -463,25 +463,29 @@ int drm_gem_shmem_madvise(struct drm_gem_shmem_object *shmem, int madv)
 }
 EXPORT_SYMBOL(drm_gem_shmem_madvise);
 
-void drm_gem_shmem_purge(struct drm_gem_shmem_object *shmem)
+static void drm_gem_shmem_unpin_pages(struct drm_gem_shmem_object *shmem)
 {
 	struct drm_gem_object *obj = &shmem->base;
 	struct drm_device *dev = obj->dev;
 
 	dma_resv_assert_held(shmem->base.resv);
 
-	drm_WARN_ON(obj->dev, !drm_gem_shmem_is_purgeable(shmem));
-
 	dma_unmap_sgtable(dev->dev, shmem->sgt, DMA_BIDIRECTIONAL, 0);
+	drm_gem_shmem_release_pages(shmem);
+	drm_vma_node_unmap(&obj->vma_node, dev->anon_inode->i_mapping);
+
 	sg_free_table(shmem->sgt);
 	kfree(shmem->sgt);
 	shmem->sgt = NULL;
+}
 
-	drm_gem_shmem_put_pages(shmem);
+void drm_gem_shmem_purge(struct drm_gem_shmem_object *shmem)
+{
+	struct drm_gem_object *obj = &shmem->base;
 
-	shmem->madv = -1;
+	drm_WARN_ON(obj->dev, !drm_gem_shmem_is_purgeable(shmem));
 
-	drm_vma_node_unmap(&obj->vma_node, dev->anon_inode->i_mapping);
+	drm_gem_shmem_unpin_pages(shmem);
 	drm_gem_free_mmap_offset(obj);
 
 	/* Our goal here is to return as much of the memory as
@@ -492,6 +496,8 @@ void drm_gem_shmem_purge(struct drm_gem_shmem_object *shmem)
 	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;
 }
 EXPORT_SYMBOL(drm_gem_shmem_purge);
 
-- 
2.39.2

[PATCH v11 05/10] drm/shmem-helper: Add memory shrinker

[Dmitry Osipenko]

Introduce common drm-shmem shrinker for DRM drivers.

To start using drm-shmem shrinker drivers should do the following:

1. Implement evict() callback of GEM object where driver should check
   whether object is purgeable or evictable using drm-shmem helpers and
   perform the shrinking action

2. Initialize drm-shmem internals using drmm_gem_shmem_init(drm_device),
   which will register drm-shmem shrinker

3. Implement madvise IOCTL that will use drm_gem_shmem_madvise()

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        | 353 +++++++++++++++++-
 .../gpu/drm/panfrost/panfrost_gem_shrinker.c  |   9 +-
 include/drm/drm_device.h                      |  10 +-
 include/drm/drm_gem_shmem_helper.h            |  52 ++-
 4 files changed, 403 insertions(+), 21 deletions(-)

diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c
index fc1cfd5f5e7a..56de12bb28b1 100644
--- a/drivers/gpu/drm/drm_gem_shmem_helper.c
+++ b/drivers/gpu/drm/drm_gem_shmem_helper.c
@@ -20,6 +20,7 @@
 #include <drm/drm_device.h>
 #include <drm/drm_drv.h>
 #include <drm/drm_gem_shmem_helper.h>
+#include <drm/drm_managed.h>
 #include <drm/drm_prime.h>
 #include <drm/drm_print.h>
 
@@ -88,8 +89,6 @@ __drm_gem_shmem_create(struct drm_device *dev, size_t size, bool private)
 	if (ret)
 		goto err_release;
 
-	INIT_LIST_HEAD(&shmem->madv_list);
-
 	if (!private) {
 		/*
 		 * Our buffers are kept pinned, so allocating them
@@ -128,6 +127,57 @@ 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_resv_assert_held(struct drm_gem_shmem_object *shmem)
+{
+	/*
+	 * Destroying the object is a special case.. drm_gem_shmem_free()
+	 * calls many things that WARN_ON if the obj lock is not held.  But
+	 * acquiring the obj lock in drm_gem_shmem_free() can cause a locking
+	 * order inversion between reservation_ww_class_mutex and fs_reclaim.
+	 *
+	 * This deadlock is not actually possible, because no one should
+	 * be already holding the lock when drm_gem_shmem_free() is called.
+	 * Unfortunately lockdep is not aware of this detail.  So when the
+	 * refcount drops to zero, we pretend it is already locked.
+	 */
+	if (kref_read(&shmem->base.refcount))
+		dma_resv_assert_held(shmem->base.resv);
+}
+
+static bool drm_gem_shmem_is_evictable(struct drm_gem_shmem_object *shmem)
+{
+	dma_resv_assert_held(shmem->base.resv);
+
+	return (shmem->madv >= 0) && shmem->base.funcs->evict &&
+		shmem->pages_use_count && !shmem->pages_pin_count &&
+		!shmem->base.dma_buf && !shmem->base.import_attach &&
+		shmem->sgt && !shmem->evicted;
+}
+
+static void
+drm_gem_shmem_update_pages_state(struct drm_gem_shmem_object *shmem)
+{
+	struct drm_gem_object *obj = &shmem->base;
+	struct drm_gem_shmem *shmem_mm = obj->dev->shmem_mm;
+	struct drm_gem_shmem_shrinker *shmem_shrinker = &shmem_mm->shrinker;
+
+	drm_gem_shmem_resv_assert_held(shmem);
+
+	if (!shmem_shrinker || obj->import_attach)
+		return;
+
+	if (shmem->madv < 0)
+		drm_gem_lru_remove(&shmem->base);
+	else if (drm_gem_shmem_is_evictable(shmem) || drm_gem_shmem_is_purgeable(shmem))
+		drm_gem_lru_move_tail(&shmem_shrinker->lru_evictable, &shmem->base);
+	else if (shmem->evicted)
+		drm_gem_lru_move_tail(&shmem_shrinker->lru_evicted, &shmem->base);
+	else if (!shmem->pages)
+		drm_gem_lru_remove(&shmem->base);
+	else
+		drm_gem_lru_move_tail(&shmem_shrinker->lru_pinned, &shmem->base);
+}
+
 /**
  * drm_gem_shmem_free - Free resources associated with a shmem GEM object
  * @shmem: shmem GEM object to free
@@ -142,7 +192,8 @@ void drm_gem_shmem_free(struct drm_gem_shmem_object *shmem)
 	if (obj->import_attach) {
 		drm_prime_gem_destroy(obj, shmem->sgt);
 	} else {
-		dma_resv_lock(shmem->base.resv, NULL);
+		/* take out shmem GEM object from the memory shrinker */
+		drm_gem_shmem_madvise(shmem, -1);
 
 		drm_WARN_ON(obj->dev, shmem->vmap_use_count);
 
@@ -152,12 +203,10 @@ 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);
 
 		drm_WARN_ON(obj->dev, shmem->pages_use_count);
-
-		dma_resv_unlock(shmem->base.resv);
 	}
 
 	drm_gem_object_release(obj);
@@ -178,6 +227,11 @@ drm_gem_shmem_acquire_pages(struct drm_gem_shmem_object *shmem)
 		return -ENOMEM;
 	}
 
+	if (shmem->pages) {
+		drm_WARN_ON(obj->dev, !shmem->evicted);
+		return 0;
+	}
+
 	if (drm_WARN_ON(obj->dev, !shmem->pages_use_count))
 		return -EINVAL;
 
@@ -212,13 +266,20 @@ static int drm_gem_shmem_get_pages(struct drm_gem_shmem_object *shmem)
 	if (shmem->madv < 0)
 		return -ENOMEM;
 
-	if (shmem->pages_use_count++ > 0)
+	if (shmem->pages_use_count++ > 0) {
+		err = drm_gem_shmem_swapin(shmem);
+		if (err)
+			goto err_zero_use;
+
 		return 0;
+	}
 
 	err = drm_gem_shmem_acquire_pages(shmem);
 	if (err)
 		goto err_zero_use;
 
+	drm_gem_shmem_update_pages_state(shmem);
+
 	return 0;
 
 err_zero_use:
@@ -232,7 +293,12 @@ drm_gem_shmem_release_pages(struct drm_gem_shmem_object *shmem)
 {
 	struct drm_gem_object *obj = &shmem->base;
 
-	dma_resv_assert_held(shmem->base.resv);
+	drm_gem_shmem_resv_assert_held(shmem);
+
+	if (!shmem->pages) {
+		drm_WARN_ON(obj->dev, !shmem->evicted && shmem->madv >= 0);
+		return;
+	}
 
 #ifdef CONFIG_X86
 	if (shmem->map_wc)
@@ -255,7 +321,7 @@ void drm_gem_shmem_put_pages(struct drm_gem_shmem_object *shmem)
 {
 	struct drm_gem_object *obj = &shmem->base;
 
-	dma_resv_assert_held(shmem->base.resv);
+	drm_gem_shmem_resv_assert_held(shmem);
 
 	if (drm_WARN_ON_ONCE(obj->dev, !shmem->pages_use_count))
 		return;
@@ -264,6 +330,8 @@ void drm_gem_shmem_put_pages(struct drm_gem_shmem_object *shmem)
 		return;
 
 	drm_gem_shmem_release_pages(shmem);
+
+	drm_gem_shmem_update_pages_state(shmem);
 }
 EXPORT_SYMBOL(drm_gem_shmem_put_pages);
 
@@ -452,13 +520,15 @@ drm_gem_shmem_create_with_handle(struct drm_file *file_priv,
  */
 int drm_gem_shmem_madvise(struct drm_gem_shmem_object *shmem, int madv)
 {
-	dma_resv_assert_held(shmem->base.resv);
+	drm_gem_shmem_resv_assert_held(shmem);
 
 	if (shmem->madv >= 0)
 		shmem->madv = madv;
 
 	madv = shmem->madv;
 
+	drm_gem_shmem_update_pages_state(shmem);
+
 	return (madv >= 0);
 }
 EXPORT_SYMBOL(drm_gem_shmem_madvise);
@@ -470,6 +540,9 @@ static void drm_gem_shmem_unpin_pages(struct drm_gem_shmem_object *shmem)
 
 	dma_resv_assert_held(shmem->base.resv);
 
+	if (shmem->evicted)
+		return;
+
 	dma_unmap_sgtable(dev->dev, shmem->sgt, DMA_BIDIRECTIONAL, 0);
 	drm_gem_shmem_release_pages(shmem);
 	drm_vma_node_unmap(&obj->vma_node, dev->anon_inode->i_mapping);
@@ -498,9 +571,60 @@ void drm_gem_shmem_purge(struct drm_gem_shmem_object *shmem)
 	invalidate_mapping_pages(file_inode(obj->filp)->i_mapping, 0, (loff_t)-1);
 
 	shmem->madv = -1;
+	shmem->evicted = false;
+	drm_gem_shmem_update_pages_state(shmem);
 }
 EXPORT_SYMBOL(drm_gem_shmem_purge);
 
+/**
+ * drm_gem_shmem_swapin() - 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_swapin(struct drm_gem_shmem_object *shmem)
+{
+	struct drm_gem_object *obj = &shmem->base;
+	struct sg_table *sgt;
+	int err;
+
+	dma_resv_assert_held(shmem->base.resv);
+
+	if (shmem->evicted) {
+		err = drm_gem_shmem_acquire_pages(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(shmem);
+	}
+
+	if (!shmem->pages)
+		return -ENOMEM;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(drm_gem_shmem_swapin);
+
 /**
  * drm_gem_shmem_dumb_create - Create a dumb shmem buffer object
  * @file: DRM file structure to create the dumb buffer for
@@ -547,22 +671,33 @@ 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_unpinned;
+	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 ||
-	    drm_WARN_ON_ONCE(obj->dev, !shmem->pages) ||
-	    shmem->madv < 0) {
+	/* Sanity-check that we have the pages pointer when it should present */
+	pages_unpinned = (shmem->evicted || shmem->madv < 0 || !shmem->pages_use_count);
+	drm_WARN_ON_ONCE(obj->dev, !shmem->pages ^ pages_unpinned);
+
+	if (page_offset >= num_pages || (!shmem->pages && !shmem->evicted)) {
 		ret = VM_FAULT_SIGBUS;
 	} else {
+		err = drm_gem_shmem_swapin(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;
@@ -585,6 +720,7 @@ static void drm_gem_shmem_vm_open(struct vm_area_struct *vma)
 	if (!drm_WARN_ON_ONCE(obj->dev, !shmem->pages_use_count))
 		shmem->pages_use_count++;
 
+	drm_gem_shmem_update_pages_state(shmem);
 	dma_resv_unlock(shmem->base.resv);
 
 	drm_gem_vm_open(vma);
@@ -666,7 +802,9 @@ void drm_gem_shmem_print_info(const struct drm_gem_shmem_object *shmem,
 
 	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);
 
@@ -694,7 +832,7 @@ struct sg_table *drm_gem_shmem_get_sg_table(struct drm_gem_shmem_object *shmem)
 }
 EXPORT_SYMBOL_GPL(drm_gem_shmem_get_sg_table);
 
-static struct sg_table *drm_gem_shmem_get_pages_sgt_locked(struct drm_gem_shmem_object *shmem)
+struct sg_table *drm_gem_shmem_get_pages_sgt_locked(struct drm_gem_shmem_object *shmem)
 {
 	struct drm_gem_object *obj = &shmem->base;
 	int ret;
@@ -721,6 +859,8 @@ static struct sg_table *drm_gem_shmem_get_pages_sgt_locked(struct drm_gem_shmem_
 
 	shmem->sgt = sgt;
 
+	drm_gem_shmem_update_pages_state(shmem);
+
 	return sgt;
 
 err_free_sgt:
@@ -797,6 +937,191 @@ 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_gem_shmem_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 *shmem_shrinker =
+					to_drm_gem_shmem_shrinker(shrinker);
+	unsigned long count = shmem_shrinker->lru_evictable.count;
+
+	if (count >= SHRINK_EMPTY)
+		return SHRINK_EMPTY - 1;
+
+	return count ?: SHRINK_EMPTY;
+}
+
+void drm_gem_shmem_evict(struct drm_gem_shmem_object *shmem)
+{
+	struct drm_gem_object *obj = &shmem->base;
+
+	drm_WARN_ON(obj->dev, !drm_gem_shmem_is_evictable(shmem));
+	drm_WARN_ON(obj->dev, shmem->evicted);
+
+	drm_gem_shmem_unpin_pages(shmem);
+
+	shmem->evicted = true;
+	drm_gem_shmem_update_pages_state(shmem);
+}
+EXPORT_SYMBOL_GPL(drm_gem_shmem_evict);
+
+static bool drm_gem_shmem_shrinker_evict(struct drm_gem_object *obj)
+{
+	struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj);
+	int err;
+
+	if (!drm_gem_shmem_is_evictable(shmem) ||
+	    get_nr_swap_pages() < obj->size >> PAGE_SHIFT)
+		return false;
+
+	err = drm_gem_evict(obj);
+	if (err)
+		return false;
+
+	return true;
+}
+
+static bool drm_gem_shmem_shrinker_purge(struct drm_gem_object *obj)
+{
+	struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj);
+	int err;
+
+	if (!drm_gem_shmem_is_purgeable(shmem))
+		return false;
+
+	err = drm_gem_evict(obj);
+	if (err)
+		return false;
+
+	return true;
+}
+
+static unsigned long
+drm_gem_shmem_shrinker_scan_objects(struct shrinker *shrinker,
+				    struct shrink_control *sc)
+{
+	struct drm_gem_shmem_shrinker *shmem_shrinker;
+	unsigned long nr_to_scan = sc->nr_to_scan;
+	unsigned long remaining = 0;
+	unsigned long freed = 0;
+
+	shmem_shrinker = to_drm_gem_shmem_shrinker(shrinker);
+
+	/* purge as many objects as we can */
+	freed += drm_gem_lru_scan(&shmem_shrinker->lru_evictable,
+				  nr_to_scan, &remaining,
+				  drm_gem_shmem_shrinker_purge);
+
+	/* evict as many objects as we can */
+	if (freed < nr_to_scan)
+		freed += drm_gem_lru_scan(&shmem_shrinker->lru_evictable,
+					  nr_to_scan - freed, &remaining,
+					  drm_gem_shmem_shrinker_evict);
+
+	return (freed > 0 && remaining > 0) ? freed : SHRINK_STOP;
+}
+
+static int drm_gem_shmem_shrinker_init(struct drm_gem_shmem *shmem_mm,
+				       const char *shrinker_name)
+{
+	struct drm_gem_shmem_shrinker *shmem_shrinker = &shmem_mm->shrinker;
+	int err;
+
+	shmem_shrinker->base.count_objects = drm_gem_shmem_shrinker_count_objects;
+	shmem_shrinker->base.scan_objects = drm_gem_shmem_shrinker_scan_objects;
+	shmem_shrinker->base.seeks = DEFAULT_SEEKS;
+
+	mutex_init(&shmem_shrinker->lock);
+	drm_gem_lru_init(&shmem_shrinker->lru_evictable, &shmem_shrinker->lock);
+	drm_gem_lru_init(&shmem_shrinker->lru_evicted, &shmem_shrinker->lock);
+	drm_gem_lru_init(&shmem_shrinker->lru_pinned, &shmem_shrinker->lock);
+
+	err = register_shrinker(&shmem_shrinker->base, shrinker_name);
+	if (err) {
+		mutex_destroy(&shmem_shrinker->lock);
+		return err;
+	}
+
+	return 0;
+}
+
+static void drm_gem_shmem_shrinker_release(struct drm_device *dev,
+					   struct drm_gem_shmem *shmem_mm)
+{
+	struct drm_gem_shmem_shrinker *shmem_shrinker = &shmem_mm->shrinker;
+
+	unregister_shrinker(&shmem_shrinker->base);
+	drm_WARN_ON(dev, !list_empty(&shmem_shrinker->lru_evictable.list));
+	drm_WARN_ON(dev, !list_empty(&shmem_shrinker->lru_evicted.list));
+	drm_WARN_ON(dev, !list_empty(&shmem_shrinker->lru_pinned.list));
+	mutex_destroy(&shmem_shrinker->lock);
+}
+
+static int drm_gem_shmem_init(struct drm_device *dev)
+{
+	int err;
+
+	if (drm_WARN_ON(dev, dev->shmem_mm))
+		return -EBUSY;
+
+	dev->shmem_mm = kzalloc(sizeof(*dev->shmem_mm), GFP_KERNEL);
+	if (!dev->shmem_mm)
+		return -ENOMEM;
+
+	err = drm_gem_shmem_shrinker_init(dev->shmem_mm, dev->unique);
+	if (err)
+		goto free_gem_shmem;
+
+	return 0;
+
+free_gem_shmem:
+	kfree(dev->shmem_mm);
+	dev->shmem_mm = NULL;
+
+	return err;
+}
+
+static void drm_gem_shmem_release(struct drm_device *dev, void *ptr)
+{
+	struct drm_gem_shmem *shmem_mm = dev->shmem_mm;
+
+	drm_gem_shmem_shrinker_release(dev, shmem_mm);
+	dev->shmem_mm = NULL;
+	kfree(shmem_mm);
+}
+
+/**
+ * drmm_gem_shmem_init() - Initialize drm-shmem internals
+ * @dev: DRM device
+ *
+ * Cleanup is automatically managed as part of DRM device releasing.
+ * Calling this function multiple times will result in a error.
+ *
+ * Returns:
+ * 0 on success or a negative error code on failure.
+ */
+int drmm_gem_shmem_init(struct drm_device *dev)
+{
+	int err;
+
+	err = drm_gem_shmem_init(dev);
+	if (err)
+		return err;
+
+	err = drmm_add_action_or_reset(dev, drm_gem_shmem_release, NULL);
+	if (err)
+		return err;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(drmm_gem_shmem_init);
+
 MODULE_DESCRIPTION("DRM SHMEM memory-management helpers");
 MODULE_IMPORT_NS(DMA_BUF);
 MODULE_LICENSE("GPL v2");
diff --git a/drivers/gpu/drm/panfrost/panfrost_gem_shrinker.c b/drivers/gpu/drm/panfrost/panfrost_gem_shrinker.c
index 6a71a2555f85..865a989d67c8 100644
--- a/drivers/gpu/drm/panfrost/panfrost_gem_shrinker.c
+++ b/drivers/gpu/drm/panfrost/panfrost_gem_shrinker.c
@@ -15,6 +15,13 @@
 #include "panfrost_gem.h"
 #include "panfrost_mmu.h"
 
+static bool panfrost_gem_shmem_is_purgeable(struct drm_gem_shmem_object *shmem)
+{
+	return (shmem->madv > 0) &&
+		!shmem->pages_pin_count && shmem->sgt &&
+		!shmem->base.dma_buf && !shmem->base.import_attach;
+}
+
 static unsigned long
 panfrost_gem_shrinker_count(struct shrinker *shrinker, struct shrink_control *sc)
 {
@@ -27,7 +34,7 @@ panfrost_gem_shrinker_count(struct shrinker *shrinker, struct shrink_control *sc
 		return 0;
 
 	list_for_each_entry(shmem, &pfdev->shrinker_list, madv_list) {
-		if (drm_gem_shmem_is_purgeable(shmem))
+		if (panfrost_gem_shmem_is_purgeable(shmem))
 			count += shmem->base.size >> PAGE_SHIFT;
 	}
 
diff --git a/include/drm/drm_device.h b/include/drm/drm_device.h
index 7cf4afae2e79..a978f0cb5e84 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;
 
@@ -290,8 +291,13 @@ struct drm_device {
 	/** @vma_offset_manager: GEM information */
 	struct drm_vma_offset_manager *vma_offset_manager;
 
-	/** @vram_mm: VRAM MM memory manager */
-	struct drm_vram_mm *vram_mm;
+	union {
+		/** @vram_mm: VRAM MM memory manager */
+		struct drm_vram_mm *vram_mm;
+
+		/** @shmem_mm: SHMEM GEM memory manager */
+		struct drm_gem_shmem *shmem_mm;
+	};
 
 	/**
 	 * @switch_power_state:
diff --git a/include/drm/drm_gem_shmem_helper.h b/include/drm/drm_gem_shmem_helper.h
index 7d823c9fc480..e99f1715514b 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>
@@ -13,6 +14,7 @@
 #include <drm/drm_prime.h>
 
 struct dma_buf_attachment;
+struct drm_device;
 struct drm_mode_create_dumb;
 struct drm_printer;
 struct sg_table;
@@ -52,8 +54,8 @@ 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;
 
@@ -100,6 +102,12 @@ struct drm_gem_shmem_object {
 	 * @map_wc: map object write-combined (instead of using shmem defaults).
 	 */
 	bool map_wc : 1;
+
+	/**
+	 * @evicted: True if shmem pages are evicted by the memory shrinker.
+	 * Used internally by memory shrinker.
+	 */
+	bool evicted : 1;
 };
 
 #define to_drm_gem_shmem_obj(obj) \
@@ -121,11 +129,17 @@ int drm_gem_shmem_madvise(struct drm_gem_shmem_object *shmem, int madv);
 
 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;
+	dma_resv_assert_held(shmem->base.resv);
+
+	return (shmem->madv > 0) && shmem->base.funcs->evict &&
+		shmem->pages_use_count && !shmem->pages_pin_count &&
+		!shmem->base.dma_buf && !shmem->base.import_attach &&
+		(shmem->sgt || shmem->evicted);
 }
 
+int drm_gem_shmem_swapin(struct drm_gem_shmem_object *shmem);
+
+void drm_gem_shmem_evict(struct drm_gem_shmem_object *shmem);
 void 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);
@@ -269,6 +283,36 @@ 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 - Memory shrinker of GEM shmem memory manager
+ */
+struct drm_gem_shmem_shrinker {
+	/** @base: Shrinker for purging shmem GEM objects */
+	struct shrinker base;
+
+	/** @lock: Protects @lru_* */
+	struct mutex lock;
+
+	/** @lru_pinned: List of pinned shmem GEM objects */
+	struct drm_gem_lru lru_pinned;
+
+	/** @lru_evictable: List of shmem GEM objects to be evicted */
+	struct drm_gem_lru lru_evictable;
+
+	/** @lru_evicted: List of evicted shmem GEM objects */
+	struct drm_gem_lru lru_evicted;
+};
+
+/**
+ * struct drm_gem_shmem - GEM shmem memory manager
+ */
+struct drm_gem_shmem {
+	/** @shrinker: GEM shmem shrinker */
+	struct drm_gem_shmem_shrinker shrinker;
+};
+
+int drmm_gem_shmem_init(struct drm_device *dev);
+
 /*
  * Driver ops
  */
-- 
2.39.2

[PATCH v11 06/10] drm/shmem-helper: Remove obsoleted is_iomem test

[Dmitry Osipenko]

Everything that uses the mapped buffer should by agnostic to is_iomem.
The only reason for the is_iomem test is is that we're setting shmem->vaddr
to the returned map->vaddr. Now that the shmem->vaddr code is gone, remove
the obsoleted is_iomem test to clean up the code.

Suggested-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, 6 deletions(-)

diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c
index 56de12bb28b1..ba1db7c5659c 100644
--- a/drivers/gpu/drm/drm_gem_shmem_helper.c
+++ b/drivers/gpu/drm/drm_gem_shmem_helper.c
@@ -409,12 +409,6 @@ int drm_gem_shmem_vmap(struct drm_gem_shmem_object *shmem,
 
 	if (obj->import_attach) {
 		ret = dma_buf_vmap(obj->import_attach->dmabuf, map);
-		if (!ret) {
-			if (drm_WARN_ON(obj->dev, map->is_iomem)) {
-				dma_buf_vunmap(obj->import_attach->dmabuf, map);
-				return -EIO;
-			}
-		}
 	} else {
 		pgprot_t prot = PAGE_KERNEL;
 
-- 
2.39.2

[PATCH v11 07/10] drm/shmem-helper: Export drm_gem_shmem_get_pages_sgt_locked()

[Dmitry Osipenko]

Export drm_gem_shmem_get_pages_sgt_locked() that will be used by virtio-gpu
shrinker during GEM swap-in operation done under the held reservation lock.

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

diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c
index ba1db7c5659c..c5707fbcbb40 100644
--- a/drivers/gpu/drm/drm_gem_shmem_helper.c
+++ b/drivers/gpu/drm/drm_gem_shmem_helper.c
@@ -864,6 +864,7 @@ struct sg_table *drm_gem_shmem_get_pages_sgt_locked(struct drm_gem_shmem_object
 	drm_gem_shmem_put_pages(shmem);
 	return ERR_PTR(ret);
 }
+EXPORT_SYMBOL_GPL(drm_gem_shmem_get_pages_sgt_locked);
 
 /**
  * drm_gem_shmem_get_pages_sgt - Pin pages, dma map them, and return a
diff --git a/include/drm/drm_gem_shmem_helper.h b/include/drm/drm_gem_shmem_helper.h
index e99f1715514b..61aaacc6cb99 100644
--- a/include/drm/drm_gem_shmem_helper.h
+++ b/include/drm/drm_gem_shmem_helper.h
@@ -144,6 +144,7 @@ void 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);
+struct sg_table *drm_gem_shmem_get_pages_sgt_locked(struct drm_gem_shmem_object *shmem);
 
 void drm_gem_shmem_print_info(const struct drm_gem_shmem_object *shmem,
 			      struct drm_printer *p, unsigned int indent);
-- 
2.39.2

[PATCH v11 08/10] drm/gem: Add drm_gem_pin_unlocked()

[Dmitry Osipenko]

Add unlocked variants of drm_gem_un/pin() functions. These new helpers
will take care of GEM dma-reservation locking for DRM drivers.

VirtIO-GPU driver will use these helpers to pin shmem framebuffers,
preventing them from eviction during scanout.

Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
---
 drivers/gpu/drm/drm_gem.c | 29 +++++++++++++++++++++++++++++
 include/drm/drm_gem.h     |  3 +++
 2 files changed, 32 insertions(+)

diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c
index e5b2c077b314..3b16026e47f8 100644
--- a/drivers/gpu/drm/drm_gem.c
+++ b/drivers/gpu/drm/drm_gem.c
@@ -1167,6 +1167,35 @@ void drm_gem_unpin(struct drm_gem_object *obj)
 		obj->funcs->unpin(obj);
 }
 
+int drm_gem_pin_unlocked(struct drm_gem_object *obj)
+{
+	int ret;
+
+	if (!obj->funcs->pin)
+		return 0;
+
+	ret = dma_resv_lock_interruptible(obj->resv, NULL);
+	if (ret)
+		return ret;
+
+	ret = obj->funcs->pin(obj);
+	dma_resv_unlock(obj->resv);
+
+	return ret;
+}
+EXPORT_SYMBOL(drm_gem_pin_unlocked);
+
+void drm_gem_unpin_unlocked(struct drm_gem_object *obj)
+{
+	if (!obj->funcs->unpin)
+		return;
+
+	dma_resv_lock(obj->resv, NULL);
+	obj->funcs->unpin(obj);
+	dma_resv_unlock(obj->resv);
+}
+EXPORT_SYMBOL(drm_gem_unpin_unlocked);
+
 int drm_gem_vmap(struct drm_gem_object *obj, struct iosys_map *map)
 {
 	int ret;
diff --git a/include/drm/drm_gem.h b/include/drm/drm_gem.h
index 7bd8e2bbbb36..b0a03d2dac99 100644
--- a/include/drm/drm_gem.h
+++ b/include/drm/drm_gem.h
@@ -493,4 +493,7 @@ unsigned long drm_gem_lru_scan(struct drm_gem_lru *lru,
 
 int drm_gem_evict(struct drm_gem_object *obj);
 
+int drm_gem_pin_unlocked(struct drm_gem_object *obj);
+void drm_gem_unpin_unlocked(struct drm_gem_object *obj);
+
 #endif /* __DRM_GEM_H__ */
-- 
2.39.2

[PATCH v11 09/10] drm/virtio: Support memory shrinking

[Dmitry Osipenko]

Support generic drm-shmem memory shrinker and add new madvise IOCTL to
the VirtIO-GPU driver. 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 file or partition.

Acked-by: Gerd Hoffmann <kraxel@redhat.com>
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    |  18 +++-
 drivers/gpu/drm/virtio/virtgpu_gem.c    |  52 +++++++++
 drivers/gpu/drm/virtio/virtgpu_ioctl.c  |  37 +++++++
 drivers/gpu/drm/virtio/virtgpu_kms.c    |   8 ++
 drivers/gpu/drm/virtio/virtgpu_object.c | 137 +++++++++++++++++++-----
 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, 297 insertions(+), 31 deletions(-)

diff --git a/drivers/gpu/drm/virtio/virtgpu_drv.h b/drivers/gpu/drm/virtio/virtgpu_drv.h
index af6ffb696086..07eb8d3e5cfd 100644
--- a/drivers/gpu/drm/virtio/virtgpu_drv.h
+++ b/drivers/gpu/drm/virtio/virtgpu_drv.h
@@ -89,6 +89,7 @@ struct virtio_gpu_object {
 	uint32_t hw_res_handle;
 	bool dumb;
 	bool created;
+	bool detached;
 	bool host3d_blob, guest_blob;
 	uint32_t blob_mem, blob_flags;
 
@@ -277,7 +278,7 @@ 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);
 
@@ -313,6 +314,10 @@ 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);
+int virtio_gpu_gem_madvise(struct virtio_gpu_object *obj, int madv);
 
 /* virtgpu_vq.c */
 int virtio_gpu_alloc_vbufs(struct virtio_gpu_device *vgdev);
@@ -324,6 +329,8 @@ 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,
@@ -344,6 +351,9 @@ 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,
@@ -456,6 +466,8 @@ int virtio_gpu_object_create(struct virtio_gpu_device *vgdev,
 
 bool virtio_gpu_is_shmem(struct virtio_gpu_object *bo);
 
+int virtio_gpu_reattach_shmem_object(struct virtio_gpu_object *bo);
+
 int virtio_gpu_resource_id_get(struct virtio_gpu_device *vgdev,
 			       uint32_t *resid);
 /* virtgpu_prime.c */
@@ -486,4 +498,8 @@ 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..8f65911b1e99 100644
--- a/drivers/gpu/drm/virtio/virtgpu_gem.c
+++ b/drivers/gpu/drm/virtio/virtgpu_gem.c
@@ -294,3 +294,55 @@ 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 virtio_gpu_object *bo;
+	int ret = 0;
+	u32 i;
+
+	for (i = 0; i < objs->nents; i++) {
+		bo = gem_to_virtio_gpu_obj(objs->objs[i]);
+
+		if (virtio_gpu_is_shmem(bo) && bo->detached) {
+			ret = virtio_gpu_reattach_shmem_object(bo);
+			if (ret)
+				break;
+		}
+	}
+
+	return ret;
+}
+
+int virtio_gpu_gem_madvise(struct virtio_gpu_object *bo, int madv)
+{
+	int ret;
+
+	/* only shmem BOs are supported by shrinker */
+	if (!virtio_gpu_is_shmem(bo) || !bo->base.pages_mark_dirty_on_put)
+		return 1;
+
+	dma_resv_lock(bo->base.base.resv, NULL);
+	ret = drm_gem_shmem_madvise(&bo->base, madv);
+	dma_resv_unlock(bo->base.base.resv);
+
+	return ret;
+}
+
+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 da45215a933d..179d5ddfe300 100644
--- a/drivers/gpu/drm/virtio/virtgpu_ioctl.c
+++ b/drivers/gpu/drm/virtio/virtgpu_ioctl.c
@@ -214,6 +214,10 @@ 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);
@@ -428,6 +432,10 @@ 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;
@@ -487,6 +495,10 @@ 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);
@@ -850,6 +862,28 @@ 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),
@@ -889,4 +923,7 @@ 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 27b7f14dae89..b80cf76cbbef 100644
--- a/drivers/gpu/drm/virtio/virtgpu_kms.c
+++ b/drivers/gpu/drm/virtio/virtgpu_kms.c
@@ -240,6 +240,12 @@ int virtio_gpu_init(struct virtio_device *vdev, struct drm_device *dev)
 		goto err_scanouts;
 	}
 
+	ret = drmm_gem_shmem_init(dev);
+	if (ret) {
+		DRM_ERROR("shmem init failed\n");
+		goto err_modeset;
+	}
+
 	virtio_device_ready(vgdev->vdev);
 
 	if (num_capsets)
@@ -252,6 +258,8 @@ 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:
diff --git a/drivers/gpu/drm/virtio/virtgpu_object.c b/drivers/gpu/drm/virtio/virtgpu_object.c
index c7e74cf13022..70dcd19266dc 100644
--- a/drivers/gpu/drm/virtio/virtgpu_object.c
+++ b/drivers/gpu/drm/virtio/virtgpu_object.c
@@ -97,39 +97,54 @@ 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);
+
+	bo->detached = true;
+
+	return 0;
 }
 
-struct drm_gem_object *virtio_gpu_create_object(struct drm_device *dev,
-						size_t size)
+static int virtio_gpu_shmem_evict(struct drm_gem_object *obj)
 {
-	struct virtio_gpu_object_shmem *shmem;
-	struct drm_gem_shmem_object *dshmem;
+	struct virtio_gpu_object *bo = gem_to_virtio_gpu_obj(obj);
+	int err;
+
+	/*
+	 * 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.
+	 */
+	if (!bo->base.evicted) {
+		err = virtio_gpu_detach_object_fenced(bo);
+		if (err)
+			return err;
+	}
 
-	shmem = kzalloc(sizeof(*shmem), GFP_KERNEL);
-	if (!shmem)
-		return ERR_PTR(-ENOMEM);
+	if (drm_gem_shmem_is_purgeable(&bo->base)) {
+		err = virtio_gpu_gem_host_mem_release(bo);
+		if (err) {
+			virtio_gpu_reattach_shmem_object(bo);
+			return err;
+		}
 
-	dshmem = &shmem->base.base;
-	dshmem->base.funcs = &virtio_gpu_shmem_funcs;
-	return &dshmem->base;
+		drm_gem_shmem_purge(&bo->base);
+	} else {
+		drm_gem_shmem_evict(&bo->base);
+	}
+
+	return 0;
 }
 
 static int virtio_gpu_object_shmem_init(struct virtio_gpu_device *vgdev,
@@ -142,7 +157,7 @@ static int virtio_gpu_object_shmem_init(struct virtio_gpu_device *vgdev,
 	struct sg_table *pages;
 	int si;
 
-	pages = drm_gem_shmem_get_pages_sgt(&bo->base);
+	pages = drm_gem_shmem_get_pages_sgt_locked(&bo->base);
 	if (IS_ERR(pages))
 		return PTR_ERR(pages);
 
@@ -176,6 +191,65 @@ static int virtio_gpu_object_shmem_init(struct virtio_gpu_device *vgdev,
 	return 0;
 }
 
+int virtio_gpu_reattach_shmem_object(struct virtio_gpu_object *bo)
+{
+	struct virtio_gpu_device *vgdev = bo->base.base.dev->dev_private;
+	struct virtio_gpu_mem_entry *ents;
+	unsigned int nents;
+	int err;
+
+	err = drm_gem_shmem_swapin(&bo->base);
+	if (err)
+		return 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);
+
+	bo->detached = false;
+
+	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,
+	.evict = virtio_gpu_shmem_evict,
+};
+
+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,
@@ -202,7 +276,10 @@ int virtio_gpu_object_create(struct virtio_gpu_device *vgdev,
 
 	bo->dumb = params->dumb;
 
+	dma_resv_lock(bo->base.base.resv, NULL);
 	ret = virtio_gpu_object_shmem_init(vgdev, bo, &ents, &nents);
+	dma_resv_unlock(bo->base.base.resv);
+
 	if (ret != 0)
 		goto err_put_id;
 
@@ -228,10 +305,14 @@ 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;
 	} 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;
 	}
 
 	*bo_ptr = bo;
diff --git a/drivers/gpu/drm/virtio/virtgpu_plane.c b/drivers/gpu/drm/virtio/virtgpu_plane.c
index 4c09e313bebc..2b99dea26e5c 100644
--- a/drivers/gpu/drm/virtio/virtgpu_plane.c
+++ b/drivers/gpu/drm/virtio/virtgpu_plane.c
@@ -238,20 +238,32 @@ 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_pin_unlocked(&bo->base.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_unpin_unlocked(&bo->base.base);
+
 			return -ENOMEM;
+		}
 	}
 
 	return 0;
@@ -261,15 +273,21 @@ 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_unpin_unlocked(&bo->base.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 a04a9b20896d..abdf3665c0ba 100644
--- a/drivers/gpu/drm/virtio/virtgpu_vq.c
+++ b/drivers/gpu/drm/virtio/virtgpu_vq.c
@@ -545,6 +545,21 @@ 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,
@@ -645,6 +660,23 @@ 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)
 {
@@ -1108,6 +1140,14 @@ 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 7b158fcb02b4..9fb38ad16120 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
@@ -197,6 +198,15 @@ 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
@@ -247,6 +257,10 @@ 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
-- 
2.39.2

[PATCH v11 10/10] drm/panfrost: Switch to generic memory shrinker

[Dmitry Osipenko]

Replace Panfrost's custom memory shrinker with a common drm-shmem
memory shrinker.

Tested-by: Steven Price <steven.price@arm.com> # Firefly-RK3288
Reviewed-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       |  27 ++--
 drivers/gpu/drm/panfrost/panfrost_gem.c       |  30 ++--
 drivers/gpu/drm/panfrost/panfrost_gem.h       |   9 --
 .../gpu/drm/panfrost/panfrost_gem_shrinker.c  | 129 ------------------
 drivers/gpu/drm/panfrost/panfrost_job.c       |  18 ++-
 include/drm/drm_gem_shmem_helper.h            |   7 -
 8 files changed, 47 insertions(+), 178 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 7da2b3f02ed9..11622e22cf15 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 d9ba68cffb77..28f28bbdbda9 100644
--- a/drivers/gpu/drm/panfrost/panfrost_device.h
+++ b/drivers/gpu/drm/panfrost/panfrost_device.h
@@ -116,10 +116,6 @@ 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 9f3f2283b67a..e31cf9db005b 100644
--- a/drivers/gpu/drm/panfrost/panfrost_drv.c
+++ b/drivers/gpu/drm/panfrost/panfrost_drv.c
@@ -169,7 +169,6 @@ panfrost_lookup_bos(struct drm_device *dev,
 			break;
 		}
 
-		atomic_inc(&bo->gpu_usecount);
 		job->mappings[i] = mapping;
 	}
 
@@ -401,7 +400,6 @@ 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;
@@ -414,11 +412,15 @@ static int panfrost_ioctl_madvise(struct drm_device *dev, void *data,
 
 	bo = to_panfrost_bo(gem_obj);
 
+	if (bo->is_heap) {
+		args->retained = 1;
+		goto out_put_object;
+	}
+
 	ret = dma_resv_lock_interruptible(bo->base.base.resv, NULL);
 	if (ret)
 		goto out_put_object;
 
-	mutex_lock(&pfdev->shrinker_lock);
 	mutex_lock(&bo->mappings.lock);
 	if (args->madv == PANFROST_MADV_DONTNEED) {
 		struct panfrost_gem_mapping *first;
@@ -444,17 +446,8 @@ 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_move_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);
 	dma_resv_unlock(bo->base.base.resv);
 out_put_object:
 	drm_gem_object_put(gem_obj);
@@ -586,9 +579,6 @@ 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)
@@ -610,10 +600,14 @@ static int panfrost_probe(struct platform_device *pdev)
 	if (err < 0)
 		goto err_out1;
 
-	panfrost_gem_shrinker_init(ddev);
+	err = drmm_gem_shmem_init(ddev);
+	if (err < 0)
+		goto err_out2;
 
 	return 0;
 
+err_out2:
+	drm_dev_unregister(ddev);
 err_out1:
 	pm_runtime_disable(pfdev->dev);
 	panfrost_device_fini(pfdev);
@@ -629,7 +623,6 @@ static int panfrost_remove(struct platform_device *pdev)
 	struct drm_device *ddev = pfdev->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 3c812fbd126f..08d795c28b4e 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.
@@ -195,6 +185,25 @@ static int panfrost_gem_pin(struct drm_gem_object *obj)
 	return drm_gem_shmem_pin(&bo->base);
 }
 
+static int panfrost_shmem_evict(struct drm_gem_object *obj)
+{
+	struct panfrost_gem_object *bo = to_panfrost_bo(obj);
+
+	if (!drm_gem_shmem_is_purgeable(&bo->base))
+		return -EBUSY;
+
+	if (!mutex_trylock(&bo->mappings.lock))
+		return -EBUSY;
+
+	panfrost_gem_teardown_mappings_locked(bo);
+
+	drm_gem_shmem_purge(&bo->base);
+
+	mutex_unlock(&bo->mappings.lock);
+
+	return 0;
+}
+
 static const struct drm_gem_object_funcs panfrost_gem_funcs = {
 	.free = panfrost_gem_free_object,
 	.open = panfrost_gem_open,
@@ -207,6 +216,7 @@ static const struct drm_gem_object_funcs panfrost_gem_funcs = {
 	.vunmap = drm_gem_shmem_object_vunmap,
 	.mmap = drm_gem_shmem_object_mmap,
 	.vm_ops = &drm_gem_shmem_vm_ops,
+	.evict = panfrost_shmem_evict,
 };
 
 /**
diff --git a/drivers/gpu/drm/panfrost/panfrost_gem.h b/drivers/gpu/drm/panfrost/panfrost_gem.h
index ad2877eeeccd..6ad1bcedb932 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;
 };
@@ -81,7 +75,4 @@ 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 865a989d67c8..000000000000
--- a/drivers/gpu/drm/panfrost/panfrost_gem_shrinker.c
+++ /dev/null
@@ -1,129 +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 bool panfrost_gem_shmem_is_purgeable(struct drm_gem_shmem_object *shmem)
-{
-	return (shmem->madv > 0) &&
-		!shmem->pages_pin_count && shmem->sgt &&
-		!shmem->base.dma_buf && !shmem->base.import_attach;
-}
-
-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 (panfrost_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(&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, "drm-panfrost"));
-}
-
-/**
- * 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 dbc597ab46fb..98d9751d2b2c 100644
--- a/drivers/gpu/drm/panfrost/panfrost_job.c
+++ b/drivers/gpu/drm/panfrost/panfrost_job.c
@@ -272,6 +272,19 @@ 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;
@@ -283,6 +296,10 @@ 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);
 
@@ -324,7 +341,6 @@ 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);
diff --git a/include/drm/drm_gem_shmem_helper.h b/include/drm/drm_gem_shmem_helper.h
index 61aaacc6cb99..bdd4b7402355 100644
--- a/include/drm/drm_gem_shmem_helper.h
+++ b/include/drm/drm_gem_shmem_helper.h
@@ -59,13 +59,6 @@ struct drm_gem_shmem_object {
 	 */
 	int madv;
 
-	/**
-	 * @madv_list: List entry for madvise tracking
-	 *
-	 * Typically used by drivers to track purgeable objects
-	 */
-	struct list_head madv_list;
-
 	/**
 	 * @sgt: Scatter/gather table for imported PRIME buffers
 	 */
-- 
2.39.2

Re: [PATCH v11 05/10] drm/shmem-helper: Add memory shrinker

[kernel test robot]

Hi Dmitry,

I love your patch! Yet something to improve:

[auto build test ERROR on drm-misc/drm-misc-next]
[cannot apply to drm/drm-next drm-intel/for-linux-next drm-intel/for-linux-next-fixes drm-tip/drm-tip linus/master v6.2 next-20230227]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Dmitry-Osipenko/drm-shmem-helper-Factor-out-pages-alloc-release-from-drm_gem_shmem_get-put_pages/20230227-140619
base:   git://anongit.freedesktop.org/drm/drm-misc drm-misc-next
patch link:    https://lore.kernel.org/r/20230227060219.904986-6-dmitry.osipenko%40collabora.com
patch subject: [PATCH v11 05/10] drm/shmem-helper: Add memory shrinker
config: riscv-randconfig-r006-20230227 (https://download.01.org/0day-ci/archive/20230227/202302271624.aEDOT0UV-lkp@intel.com/config)
compiler: clang version 17.0.0 (https://github.com/llvm/llvm-project db89896bbbd2251fff457699635acbbedeead27f)
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # install riscv cross compiling tool for clang build
        # apt-get install binutils-riscv64-linux-gnu
        # https://github.com/intel-lab-lkp/linux/commit/c4d106484ddbebccf4219dacbc2a9975909f4c2a
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Dmitry-Osipenko/drm-shmem-helper-Factor-out-pages-alloc-release-from-drm_gem_shmem_get-put_pages/20230227-140619
        git checkout c4d106484ddbebccf4219dacbc2a9975909f4c2a
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=riscv olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=riscv SHELL=/bin/bash drivers/gpu/

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>
| Link: https://lore.kernel.org/oe-kbuild-all/202302271624.aEDOT0UV-lkp@intel.com/

All errors (new ones prefixed by >>):

   drivers/gpu/drm/drm_gem_shmem_helper.c:832:18: warning: no previous prototype for function 'drm_gem_shmem_get_pages_sgt_locked' [-Wmissing-prototypes]
   struct sg_table *drm_gem_shmem_get_pages_sgt_locked(struct drm_gem_shmem_object *shmem)
                    ^
   drivers/gpu/drm/drm_gem_shmem_helper.c:832:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
   struct sg_table *drm_gem_shmem_get_pages_sgt_locked(struct drm_gem_shmem_object *shmem)
   ^
   static 
>> drivers/gpu/drm/drm_gem_shmem_helper.c:1016:7: error: too many arguments to function call, expected 3, have 4
                                     drm_gem_shmem_shrinker_purge);
                                     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
   include/drm/drm_gem.h:489:15: note: 'drm_gem_lru_scan' declared here
   unsigned long drm_gem_lru_scan(struct drm_gem_lru *lru, unsigned nr_to_scan,
                 ^
   drivers/gpu/drm/drm_gem_shmem_helper.c:1022:8: error: too many arguments to function call, expected 3, have 4
                                             drm_gem_shmem_shrinker_evict);
                                             ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
   include/drm/drm_gem.h:489:15: note: 'drm_gem_lru_scan' declared here
   unsigned long drm_gem_lru_scan(struct drm_gem_lru *lru, unsigned nr_to_scan,
                 ^
   1 warning and 2 errors generated.


vim +1016 drivers/gpu/drm/drm_gem_shmem_helper.c

  1001	
  1002	static unsigned long
  1003	drm_gem_shmem_shrinker_scan_objects(struct shrinker *shrinker,
  1004					    struct shrink_control *sc)
  1005	{
  1006		struct drm_gem_shmem_shrinker *shmem_shrinker;
  1007		unsigned long nr_to_scan = sc->nr_to_scan;
  1008		unsigned long remaining = 0;
  1009		unsigned long freed = 0;
  1010	
  1011		shmem_shrinker = to_drm_gem_shmem_shrinker(shrinker);
  1012	
  1013		/* purge as many objects as we can */
  1014		freed += drm_gem_lru_scan(&shmem_shrinker->lru_evictable,
  1015					  nr_to_scan, &remaining,
> 1016					  drm_gem_shmem_shrinker_purge);
  1017	
  1018		/* evict as many objects as we can */
  1019		if (freed < nr_to_scan)
  1020			freed += drm_gem_lru_scan(&shmem_shrinker->lru_evictable,
  1021						  nr_to_scan - freed, &remaining,
  1022						  drm_gem_shmem_shrinker_evict);
  1023	
  1024		return (freed > 0 && remaining > 0) ? freed : SHRINK_STOP;
  1025	}
  1026	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests

Re: [PATCH v11 05/10] drm/shmem-helper: Add memory shrinker

[kernel test robot]

Hi Dmitry,

I love your patch! Perhaps something to improve:

[auto build test WARNING on drm-misc/drm-misc-next]
[cannot apply to drm/drm-next drm-intel/for-linux-next drm-intel/for-linux-next-fixes drm-tip/drm-tip linus/master v6.2 next-20230227]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Dmitry-Osipenko/drm-shmem-helper-Factor-out-pages-alloc-release-from-drm_gem_shmem_get-put_pages/20230227-140619
base:   git://anongit.freedesktop.org/drm/drm-misc drm-misc-next
patch link:    https://lore.kernel.org/r/20230227060219.904986-6-dmitry.osipenko%40collabora.com
patch subject: [PATCH v11 05/10] drm/shmem-helper: Add memory shrinker
config: s390-allyesconfig (https://download.01.org/0day-ci/archive/20230227/202302271639.sq28B3aR-lkp@intel.com/config)
compiler: s390-linux-gcc (GCC) 12.1.0
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://github.com/intel-lab-lkp/linux/commit/c4d106484ddbebccf4219dacbc2a9975909f4c2a
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Dmitry-Osipenko/drm-shmem-helper-Factor-out-pages-alloc-release-from-drm_gem_shmem_get-put_pages/20230227-140619
        git checkout c4d106484ddbebccf4219dacbc2a9975909f4c2a
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=s390 olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=s390 SHELL=/bin/bash drivers/gpu/

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>
| Link: https://lore.kernel.org/oe-kbuild-all/202302271639.sq28B3aR-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> drivers/gpu/drm/drm_gem_shmem_helper.c:832:18: warning: no previous prototype for 'drm_gem_shmem_get_pages_sgt_locked' [-Wmissing-prototypes]
     832 | struct sg_table *drm_gem_shmem_get_pages_sgt_locked(struct drm_gem_shmem_object *shmem)
         |                  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   drivers/gpu/drm/drm_gem_shmem_helper.c: In function 'drm_gem_shmem_shrinker_scan_objects':
   drivers/gpu/drm/drm_gem_shmem_helper.c:1015:47: error: passing argument 3 of 'drm_gem_lru_scan' from incompatible pointer type [-Werror=incompatible-pointer-types]
    1015 |                                   nr_to_scan, &remaining,
         |                                               ^~~~~~~~~~
         |                                               |
         |                                               long unsigned int *
   In file included from include/drm/drm_gem_shmem_helper.h:12,
                    from drivers/gpu/drm/drm_gem_shmem_helper.c:22:
   include/drm/drm_gem.h:490:39: note: expected 'bool (*)(struct drm_gem_object *)' {aka '_Bool (*)(struct drm_gem_object *)'} but argument is of type 'long unsigned int *'
     490 |                                bool (*shrink)(struct drm_gem_object *obj));
         |                                ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   drivers/gpu/drm/drm_gem_shmem_helper.c:1014:18: error: too many arguments to function 'drm_gem_lru_scan'
    1014 |         freed += drm_gem_lru_scan(&shmem_shrinker->lru_evictable,
         |                  ^~~~~~~~~~~~~~~~
   include/drm/drm_gem.h:489:15: note: declared here
     489 | unsigned long drm_gem_lru_scan(struct drm_gem_lru *lru, unsigned nr_to_scan,
         |               ^~~~~~~~~~~~~~~~
   drivers/gpu/drm/drm_gem_shmem_helper.c:1021:63: error: passing argument 3 of 'drm_gem_lru_scan' from incompatible pointer type [-Werror=incompatible-pointer-types]
    1021 |                                           nr_to_scan - freed, &remaining,
         |                                                               ^~~~~~~~~~
         |                                                               |
         |                                                               long unsigned int *
   include/drm/drm_gem.h:490:39: note: expected 'bool (*)(struct drm_gem_object *)' {aka '_Bool (*)(struct drm_gem_object *)'} but argument is of type 'long unsigned int *'
     490 |                                bool (*shrink)(struct drm_gem_object *obj));
         |                                ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   drivers/gpu/drm/drm_gem_shmem_helper.c:1020:26: error: too many arguments to function 'drm_gem_lru_scan'
    1020 |                 freed += drm_gem_lru_scan(&shmem_shrinker->lru_evictable,
         |                          ^~~~~~~~~~~~~~~~
   include/drm/drm_gem.h:489:15: note: declared here
     489 | unsigned long drm_gem_lru_scan(struct drm_gem_lru *lru, unsigned nr_to_scan,
         |               ^~~~~~~~~~~~~~~~
   cc1: some warnings being treated as errors


vim +/drm_gem_shmem_get_pages_sgt_locked +832 drivers/gpu/drm/drm_gem_shmem_helper.c

   831	
 > 832	struct sg_table *drm_gem_shmem_get_pages_sgt_locked(struct drm_gem_shmem_object *shmem)
   833	{
   834		struct drm_gem_object *obj = &shmem->base;
   835		int ret;
   836		struct sg_table *sgt;
   837	
   838		if (shmem->sgt)
   839			return shmem->sgt;
   840	
   841		drm_WARN_ON(obj->dev, obj->import_attach);
   842	
   843		ret = drm_gem_shmem_get_pages(shmem);
   844		if (ret)
   845			return ERR_PTR(ret);
   846	
   847		sgt = drm_gem_shmem_get_sg_table(shmem);
   848		if (IS_ERR(sgt)) {
   849			ret = PTR_ERR(sgt);
   850			goto err_put_pages;
   851		}
   852		/* Map the pages for use by the h/w. */
   853		ret = dma_map_sgtable(obj->dev->dev, sgt, DMA_BIDIRECTIONAL, 0);
   854		if (ret)
   855			goto err_free_sgt;
   856	
   857		shmem->sgt = sgt;
   858	
   859		drm_gem_shmem_update_pages_state(shmem);
   860	
   861		return sgt;
   862	
   863	err_free_sgt:
   864		sg_free_table(sgt);
   865		kfree(sgt);
   866	err_put_pages:
   867		drm_gem_shmem_put_pages(shmem);
   868		return ERR_PTR(ret);
   869	}
   870	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests

Re: [PATCH v11 05/10] drm/shmem-helper: Add memory shrinker

[Dmitry Osipenko]

On 2/27/23 11:25, kernel test robot wrote:
> All errors (new ones prefixed by >>):
> 
>    drivers/gpu/drm/drm_gem_shmem_helper.c:832:18: warning: no previous prototype for function 'drm_gem_shmem_get_pages_sgt_locked' [-Wmissing-prototypes]
>    struct sg_table *drm_gem_shmem_get_pages_sgt_locked(struct drm_gem_shmem_object *shmem)
>                     ^
>    drivers/gpu/drm/drm_gem_shmem_helper.c:832:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
>    struct sg_table *drm_gem_shmem_get_pages_sgt_locked(struct drm_gem_shmem_object *shmem)
>    ^
>    static 

This should've been a part of patch 7, will correct in v12.

-- 
Best regards,
Dmitry