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

Message ID 20230227060219.904986-6-dmitry.osipenko@collabora.com
State New
Headers
Series Add generic memory shrinker to VirtIO-GPU and Panfrost DRM drivers |

Commit Message

Dmitry Osipenko Feb. 27, 2023, 6:02 a.m. UTC
  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(-)
  

Comments

kernel test robot Feb. 27, 2023, 8:25 a.m. UTC | #1
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
  
kernel test robot Feb. 27, 2023, 8:56 a.m. UTC | #2
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
  
Dmitry Osipenko Feb. 27, 2023, 11:05 a.m. UTC | #3
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.
  

Patch

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
  */