diff --git a/drivers/gpu/drm/ttm/ttm_pool.c b/drivers/gpu/drm/ttm/ttm_pool.c
index 6e1fd6985ffc..38e50cf81b0a 100644
--- a/drivers/gpu/drm/ttm/ttm_pool.c
+++ b/drivers/gpu/drm/ttm/ttm_pool.c
@@ -41,6 +41,7 @@
 #include <asm/set_memory.h>
 #endif
 
+#include <drm/ttm/ttm_backup.h>
 #include <drm/ttm/ttm_pool.h>
 #include <drm/ttm/ttm_tt.h>
 #include <drm/ttm/ttm_bo.h>
@@ -58,6 +59,32 @@ struct ttm_pool_dma {
 	unsigned long vaddr;
 };
 
+/**
+ * struct ttm_pool_tt_restore - State representing restore from backup
+ * @alloced_pages: Total number of already allocated pages for the ttm_tt.
+ * @restored_pages: Number of (sub) pages restored from swap for this
+ *		     chunk of 1 << @order pages.
+ * @first_page: The ttm page ptr representing for @old_pages[0].
+ * @caching_divide: Page pointer where subsequent pages are cached.
+ * @old_pages: Backup copy of page pointers that were replaced by the new
+ *	       page allocation.
+ * @pool: The pool used for page allocation while restoring.
+ * @order: The order of the last page allocated while restoring.
+ *
+ * Recovery from backup might fail when we've recovered less than the
+ * full ttm_tt. In order not to loose any data (yet), keep information
+ * around that allows us to restart a failed ttm backup recovery.
+ */
+struct ttm_pool_tt_restore {
+	pgoff_t alloced_pages;
+	pgoff_t restored_pages;
+	struct page **first_page;
+	struct page **caching_divide;
+	struct ttm_pool *pool;
+	unsigned int order;
+	struct page *old_pages[];
+};
+
 static unsigned long page_pool_size;
 
 MODULE_PARM_DESC(page_pool_size, "Number of pages in the WC/UC/DMA pool");
@@ -354,11 +381,102 @@ static unsigned int ttm_pool_page_order(struct ttm_pool *pool, struct page *p)
 	return p->private;
 }
 
+/*
+ * To be able to insert single pages into backup directly,
+ * we need to split multi-order page allocations and make them look
+ * like single-page allocations.
+ */
+static void ttm_pool_split_for_swap(struct ttm_pool *pool, struct page *p)
+{
+	unsigned int order = ttm_pool_page_order(pool, p);
+	pgoff_t nr;
+
+	if (!order)
+		return;
+
+	split_page(p, order);
+	nr = 1UL << order;
+	while (nr--)
+		(p++)->private = 0;
+}
+
+/**
+ * DOC: Partial backup and restoration of a struct ttm_tt.
+ *
+ * Swapout using ttm_backup::ops::backup_page() and swapin using
+ * ttm_backup::ops::copy_backed_up_page() may fail.
+ * The former most likely due to lack of swap-space or memory, the latter due
+ * to lack of memory or because of signal interruption during waits.
+ *
+ * Backupfailure is easily handled by using a ttm_tt pages vector that holds
+ * both swap entries and page pointers. This has to be taken into account when
+ * restoring such a ttm_tt from backup, and when freeing it while backed up.
+ * When restoring, for simplicity, new pages are actually allocated from the
+ * pool and the contents of any old pages are copied in and then the old pages
+ * are released.
+ *
+ * For restoration failures, the struct ttm_pool_tt_restore holds sufficient state
+ * to be able to resume an interrupted restore, and that structure is freed once
+ * the restoration is complete. If the struct ttm_tt is destroyed while there
+ * is a valid struct ttm_pool_tt_restore attached, that is also properly taken
+ * care of.
+ */
+
+static bool ttm_pool_restore_valid(const struct ttm_pool_tt_restore *restore)
+{
+	return restore && restore->restored_pages < (1 << restore->order);
+}
+
+static int ttm_pool_restore_tt(struct ttm_pool_tt_restore *restore,
+			       struct ttm_backup *backup,
+			       struct ttm_operation_ctx *ctx)
+{
+	unsigned int i, nr = 1 << restore->order;
+	int ret = 0;
+
+	if (!ttm_pool_restore_valid(restore))
+		return 0;
+
+	for (i = restore->restored_pages; i < nr; ++i) {
+		struct page *p = restore->old_pages[i];
+
+		if (ttm_backup_page_ptr_is_handle(p)) {
+			unsigned long handle = ttm_backup_page_ptr_to_handle(p);
+
+			if (handle == 0)
+				continue;
+
+			ret = backup->ops->copy_backed_up_page
+				(backup, restore->first_page[i],
+				 handle, ctx->interruptible);
+			if (ret)
+				break;
+
+			backup->ops->drop(backup, handle);
+		} else if (p) {
+			/*
+			 * We could probably avoid splitting the old page
+			 * using clever logic, but ATM we don't care.
+			 */
+			ttm_pool_split_for_swap(restore->pool, p);
+			copy_highpage(restore->first_page[i], p);
+			__free_pages(p, 0);
+		}
+
+		restore->restored_pages++;
+		restore->old_pages[i] = NULL;
+		cond_resched();
+	}
+
+	return ret;
+}
+
 /* Called when we got a page, either from a pool or newly allocated */
 static int ttm_pool_page_allocated(struct ttm_pool *pool, unsigned int order,
 				   struct page *p, dma_addr_t **dma_addr,
 				   unsigned long *num_pages,
-				   struct page ***pages)
+				   struct page ***pages,
+				   struct ttm_pool_tt_restore *restore)
 {
 	unsigned int i;
 	int r;
@@ -369,6 +487,16 @@ static int ttm_pool_page_allocated(struct ttm_pool *pool, unsigned int order,
 			return r;
 	}
 
+	if (restore) {
+		memcpy(restore->old_pages, *pages,
+		       (1 << order) * sizeof(*restore->old_pages));
+		memset(*pages, 0, (1 << order) * sizeof(**pages));
+		restore->order = order;
+		restore->restored_pages = 0;
+		restore->first_page = *pages;
+		restore->alloced_pages += 1UL << order;
+	}
+
 	*num_pages -= 1 << order;
 	for (i = 1 << order; i; --i, ++(*pages), ++p)
 		**pages = p;
@@ -394,22 +522,39 @@ static void ttm_pool_free_range(struct ttm_pool *pool, struct ttm_tt *tt,
 				pgoff_t start_page, pgoff_t end_page)
 {
 	struct page **pages = &tt->pages[start_page];
+	struct ttm_backup *backup = tt->backup;
 	unsigned int order;
 	pgoff_t i, nr;
 
 	for (i = start_page; i < end_page; i += nr, pages += nr) {
 		struct ttm_pool_type *pt = NULL;
+		struct page *p = *pages;
+
+		if (ttm_backup_page_ptr_is_handle(p)) {
+			unsigned long handle = ttm_backup_page_ptr_to_handle(p);
+
+			nr = 1;
+			if (handle != 0)
+				backup->ops->drop(backup, handle);
+			continue;
+		}
+
+		if (pool) {
+			order = ttm_pool_page_order(pool, p);
+			nr = (1UL << order);
+			if (tt->dma_address)
+				ttm_pool_unmap(pool, tt->dma_address[i], nr);
 
-		order = ttm_pool_page_order(pool, *pages);
-		nr = (1UL << order);
-		if (tt->dma_address)
-			ttm_pool_unmap(pool, tt->dma_address[i], nr);
+			pt = ttm_pool_select_type(pool, caching, order);
+		} else {
+			order = p->private;
+			nr = (1UL << order);
+		}
 
-		pt = ttm_pool_select_type(pool, caching, order);
 		if (pt)
-			ttm_pool_type_give(pt, *pages);
+			ttm_pool_type_give(pt, p);
 		else
-			ttm_pool_free_page(pool, caching, order, *pages);
+			ttm_pool_free_page(pool, caching, order, p);
 	}
 }
 
@@ -453,9 +598,37 @@ int ttm_pool_alloc(struct ttm_pool *pool, struct ttm_tt *tt,
 	else
 		gfp_flags |= GFP_HIGHUSER;
 
-	for (order = min_t(unsigned int, MAX_PAGE_ORDER, __fls(num_pages));
-	     num_pages;
-	     order = min_t(unsigned int, order, __fls(num_pages))) {
+	order = min_t(unsigned int, MAX_PAGE_ORDER, __fls(num_pages));
+
+	if (tt->page_flags & TTM_TT_FLAG_PRIV_BACKED_UP) {
+		if (!tt->restore) {
+			gfp_t gfp = GFP_KERNEL | __GFP_NOWARN;
+
+			if (ctx->gfp_retry_mayfail)
+				gfp |= __GFP_RETRY_MAYFAIL;
+
+			tt->restore =
+				kvzalloc(struct_size(tt->restore, old_pages,
+						     (size_t)1 << order), gfp);
+			/* RFC: Possibly loop on -ENOMEM and reduce order. */
+			if (!tt->restore)
+				return -ENOMEM;
+		} else if (ttm_pool_restore_valid(tt->restore)) {
+			struct ttm_pool_tt_restore *restore = tt->restore;
+
+			num_pages -= restore->alloced_pages;
+			order = min_t(unsigned int, order, __fls(num_pages));
+			pages += restore->alloced_pages;
+			r = ttm_pool_restore_tt(restore, tt->backup, ctx);
+			if (r)
+				return r;
+			caching = restore->caching_divide;
+		}
+
+		tt->restore->pool = pool;
+	}
+
+	for (; num_pages; order = min_t(unsigned int, order, __fls(num_pages))) {
 		struct ttm_pool_type *pt;
 
 		page_caching = tt->caching;
@@ -472,11 +645,19 @@ int ttm_pool_alloc(struct ttm_pool *pool, struct ttm_tt *tt,
 				r = ttm_pool_page_allocated(pool, order, p,
 							    &dma_addr,
 							    &num_pages,
-							    &pages);
+							    &pages,
+							    tt->restore);
 				if (r)
 					goto error_free_page;
 
 				caching = pages;
+				if (ttm_pool_restore_valid(tt->restore)) {
+					r = ttm_pool_restore_tt(tt->restore, tt->backup,
+								ctx);
+					if (r)
+						goto error_free_all;
+				}
+
 				if (num_pages < (1 << order))
 					break;
 
@@ -496,9 +677,17 @@ int ttm_pool_alloc(struct ttm_pool *pool, struct ttm_tt *tt,
 				caching = pages;
 			}
 			r = ttm_pool_page_allocated(pool, order, p, &dma_addr,
-						    &num_pages, &pages);
+						    &num_pages, &pages,
+						    tt->restore);
 			if (r)
 				goto error_free_page;
+
+			if (ttm_pool_restore_valid(tt->restore)) {
+				r = ttm_pool_restore_tt(tt->restore, tt->backup, ctx);
+				if (r)
+					goto error_free_all;
+			}
+
 			if (PageHighMem(p))
 				caching = pages;
 		}
@@ -517,12 +706,26 @@ int ttm_pool_alloc(struct ttm_pool *pool, struct ttm_tt *tt,
 	if (r)
 		goto error_free_all;
 
+	if (tt->restore) {
+		kvfree(tt->restore);
+		tt->restore = NULL;
+	}
+
+	if (tt->page_flags & TTM_TT_FLAG_PRIV_BACKED_UP)
+		tt->page_flags &= ~(TTM_TT_FLAG_PRIV_BACKED_UP |
+				    TTM_TT_FLAG_SWAPPED);
+
 	return 0;
 
 error_free_page:
 	ttm_pool_free_page(pool, page_caching, order, p);
 
 error_free_all:
+	if (tt->page_flags & TTM_TT_FLAG_PRIV_BACKED_UP) {
+		tt->restore->caching_divide = caching;
+		return r;
+	}
+
 	num_pages = tt->num_pages - num_pages;
 	caching_divide = caching - tt->pages;
 	ttm_pool_free_range(pool, tt, tt->caching, 0, caching_divide);
@@ -549,6 +752,174 @@ void ttm_pool_free(struct ttm_pool *pool, struct ttm_tt *tt)
 }
 EXPORT_SYMBOL(ttm_pool_free);
 
+/**
+ * ttm_pool_release_backed_up() - Release content of a swapped-out struct ttm_tt
+ * @tt: The struct ttm_tt.
+ *
+ * Release handles with associated content or any remaining pages of
+ * a backed-up struct ttm_tt.
+ */
+void ttm_pool_release_backed_up(struct ttm_tt *tt)
+{
+	struct ttm_backup *backup = tt->backup;
+	struct ttm_pool_tt_restore *restore;
+	pgoff_t i, start_page = 0;
+	unsigned long handle;
+
+	if (!(tt->page_flags & TTM_TT_FLAG_PRIV_BACKED_UP))
+		return;
+
+	restore = tt->restore;
+
+	if (ttm_pool_restore_valid(restore)) {
+		pgoff_t nr = 1UL << restore->order;
+
+		for (i = restore->restored_pages; i < nr; ++i) {
+			struct page *p = restore->old_pages[i];
+
+			if (ttm_backup_page_ptr_is_handle(p)) {
+				handle = ttm_backup_page_ptr_to_handle(p);
+				if (handle == 0)
+					continue;
+
+				backup->ops->drop(backup, handle);
+			} else if (p) {
+				ttm_pool_split_for_swap(restore->pool, p);
+				__free_pages(p, 0);
+			}
+		}
+	}
+
+	if (restore) {
+		pgoff_t mid = restore->caching_divide - tt->pages;
+
+		start_page = restore->alloced_pages;
+		/* Pages that might be dma-mapped and non-cached */
+		ttm_pool_free_range(restore->pool, tt, tt->caching,
+				    0, mid);
+		/* Pages that might be dma-mapped but cached */
+		ttm_pool_free_range(restore->pool, tt, ttm_cached,
+				    mid, restore->alloced_pages);
+	}
+
+	/* Shrunken pages. Cached and not dma-mapped. */
+	ttm_pool_free_range(NULL, tt, ttm_cached, start_page, tt->num_pages);
+
+	if (restore) {
+		kvfree(restore);
+		tt->restore = NULL;
+	}
+
+	tt->page_flags &= ~(TTM_TT_FLAG_PRIV_BACKED_UP | TTM_TT_FLAG_SWAPPED);
+}
+
+/**
+ * ttm_pool_backup_tt() - Back up or purge a struct ttm_tt
+ * @pool: The pool used when allocating the struct ttm_tt.
+ * @ttm: The struct ttm_tt.
+ * @purge: Don't back up but release pages directly to system.
+ * @writeback: If !@purge, Try to write out directly to the
+ * underlying persistent media.
+ *
+ * Back up or purge a struct ttm_tt. If @purge is true, then
+ * all pages will be freed directly to the system rather than to the pool
+ * they were allocated from, making the function behave similarly to
+ * ttm_pool_free(). If @purge is false the pages will be backed up instead,
+ * exchanged for handles.
+ * A subsequent call to ttm_pool_alloc() will then read back the content and
+ * a subsequent call to ttm_pool_release_shrunken() will drop it.
+ * If backup of a page fails for whatever reason, @ttm will still be
+ * partially backed up, retaining those pages for which backup fails.
+ *
+ * Return: Number of pages actually backed up or freed, or negative
+ * error code on error.
+ */
+long ttm_pool_backup_tt(struct ttm_pool *pool, struct ttm_tt *ttm, bool purge,
+			bool writeback)
+{
+	struct ttm_backup *backup = ttm->backup;
+	struct page *page;
+	unsigned long handle;
+	gfp_t alloc_gfp;
+	gfp_t gfp;
+	int ret = 0;
+	pgoff_t shrunken = 0;
+	pgoff_t i, num_pages;
+
+	if ((!get_nr_swap_pages() && !purge) ||
+	    pool->use_dma_alloc ||
+	    (ttm->page_flags & TTM_TT_FLAG_PRIV_BACKED_UP))
+		return -EBUSY;
+
+#ifdef CONFIG_X86
+	/* Anything returned to the system needs to be cached. */
+	if (ttm->caching != ttm_cached)
+		set_pages_array_wb(ttm->pages, ttm->num_pages);
+#endif
+
+	if (ttm->dma_address || purge) {
+		for (i = 0; i < ttm->num_pages; i += num_pages) {
+			unsigned int order;
+
+			page = ttm->pages[i];
+			if (unlikely(!page)) {
+				num_pages = 1;
+				continue;
+			}
+
+			order = ttm_pool_page_order(pool, page);
+			num_pages = 1UL << order;
+			if (ttm->dma_address)
+				ttm_pool_unmap(pool, ttm->dma_address[i],
+					       num_pages);
+			if (purge) {
+				shrunken += num_pages;
+				page->private = 0;
+				__free_pages(page, order);
+				memset(ttm->pages + i, 0,
+				       num_pages * sizeof(*ttm->pages));
+			}
+		}
+	}
+
+	if (purge)
+		return shrunken;
+
+	if (pool->use_dma32)
+		gfp = GFP_DMA32;
+	else
+		gfp = GFP_HIGHUSER;
+
+	alloc_gfp = GFP_KERNEL | __GFP_HIGH | __GFP_NOWARN | __GFP_RETRY_MAYFAIL;
+
+	for (i = 0; i < ttm->num_pages; ++i) {
+		page = ttm->pages[i];
+		if (unlikely(!page))
+			continue;
+
+		ttm_pool_split_for_swap(pool, page);
+
+		handle = backup->ops->backup_page(backup, page, writeback, i,
+						  gfp, alloc_gfp);
+		if (handle) {
+			ttm->pages[i] = ttm_backup_handle_to_page_ptr(handle);
+			put_page(page);
+			shrunken++;
+		} else {
+			/* We allow partially shrunken tts */
+			ret = -ENOMEM;
+			break;
+		}
+		cond_resched();
+	}
+
+	if (shrunken)
+		ttm->page_flags |= (TTM_TT_FLAG_PRIV_BACKED_UP |
+				    TTM_TT_FLAG_SWAPPED);
+
+	return shrunken ? shrunken : ret;
+}
+
 /**
  * ttm_pool_init - Initialize a pool
  *
diff --git a/drivers/gpu/drm/ttm/ttm_tt.c b/drivers/gpu/drm/ttm/ttm_tt.c
index 578a7c37f00b..a14ba80eec44 100644
--- a/drivers/gpu/drm/ttm/ttm_tt.c
+++ b/drivers/gpu/drm/ttm/ttm_tt.c
@@ -39,6 +39,7 @@
 #include <drm/drm_cache.h>
 #include <drm/drm_device.h>
 #include <drm/drm_util.h>
+#include <drm/ttm/ttm_backup.h>
 #include <drm/ttm/ttm_bo.h>
 #include <drm/ttm/ttm_tt.h>
 
@@ -157,6 +158,7 @@ static void ttm_tt_init_fields(struct ttm_tt *ttm,
 	ttm->swap_storage = NULL;
 	ttm->sg = bo->sg;
 	ttm->caching = caching;
+	ttm->restore = NULL;
 }
 
 int ttm_tt_init(struct ttm_tt *ttm, struct ttm_buffer_object *bo,
@@ -181,6 +183,12 @@ void ttm_tt_fini(struct ttm_tt *ttm)
 		fput(ttm->swap_storage);
 	ttm->swap_storage = NULL;
 
+	ttm_pool_release_backed_up(ttm);
+	if (ttm->backup) {
+		ttm->backup->ops->fini(ttm->backup);
+		ttm->backup = NULL;
+	}
+
 	if (ttm->pages)
 		kvfree(ttm->pages);
 	else
@@ -251,6 +259,35 @@ int ttm_tt_swapin(struct ttm_tt *ttm)
 	return ret;
 }
 
+/**
+ * ttm_tt_backup() - Helper to back up a struct ttm_tt.
+ * @bdev: The TTM device.
+ * @tt: The struct ttm_tt.
+ * @purge: Don't back up but release pages directly to system,
+ * bypassing any pooling.
+ * @writeback: If !@purge, try to write out directly to the
+ * underlying persistent media.
+ *
+ * Helper for a TTM driver to use from the bo_shrink() method to shrink
+ * a struct ttm_tt, after it has done the necessary unbinding. This function
+ * will update the page accounting and call ttm_pool_shrink_tt to free pages
+ * or move them to the swap cache.
+ *
+ * Return: Number of pages freed or swapped out, or negative error code on
+ * error.
+ */
+long ttm_tt_backup(struct ttm_device *bdev, struct ttm_tt *tt, bool purge,
+		   bool writeback)
+{
+	long ret = ttm_pool_backup_tt(&bdev->pool, tt, purge, writeback);
+
+	if (ret > 0)
+		tt->page_flags &= ~TTM_TT_FLAG_PRIV_POPULATED;
+
+	return ret;
+}
+EXPORT_SYMBOL(ttm_tt_backup);
+
 /**
  * ttm_tt_swapout - swap out tt object
  *
diff --git a/include/drm/ttm/ttm_pool.h b/include/drm/ttm/ttm_pool.h
index 160d954a261e..4e4db369952b 100644
--- a/include/drm/ttm/ttm_pool.h
+++ b/include/drm/ttm/ttm_pool.h
@@ -89,6 +89,11 @@ void ttm_pool_fini(struct ttm_pool *pool);
 
 int ttm_pool_debugfs(struct ttm_pool *pool, struct seq_file *m);
 
+void ttm_pool_release_backed_up(struct ttm_tt *tt);
+
+long ttm_pool_backup_tt(struct ttm_pool *pool, struct ttm_tt *ttm,
+			bool purge, bool writeback);
+
 int ttm_pool_mgr_init(unsigned long num_pages);
 void ttm_pool_mgr_fini(void);
 
diff --git a/include/drm/ttm/ttm_tt.h b/include/drm/ttm/ttm_tt.h
index 2b9d856ff388..6b990f1e7dd0 100644
--- a/include/drm/ttm/ttm_tt.h
+++ b/include/drm/ttm/ttm_tt.h
@@ -32,11 +32,13 @@
 #include <drm/ttm/ttm_caching.h>
 #include <drm/ttm/ttm_kmap_iter.h>
 
+struct ttm_backup;
 struct ttm_device;
 struct ttm_tt;
 struct ttm_resource;
 struct ttm_buffer_object;
 struct ttm_operation_ctx;
+struct ttm_pool_tt_restore;
 
 /**
  * struct ttm_tt - This is a structure holding the pages, caching- and aperture
@@ -85,6 +87,9 @@ struct ttm_tt {
 	 * fault handling abuses the DMA api a bit and dma_map_attrs can't be
 	 * used to assure pgprot always matches.
 	 *
+	 * TTM_TT_FLAG_PRIV_BACKED_UP: TTM internal only. This is set if the
+	 * struct ttm_tt has been (possibly partially) backed up.
+	 *
 	 * TTM_TT_FLAG_PRIV_POPULATED: TTM internal only. DO NOT USE. This is
 	 * set by TTM after ttm_tt_populate() has successfully returned, and is
 	 * then unset when TTM calls ttm_tt_unpopulate().
@@ -96,6 +101,7 @@ struct ttm_tt {
 #define TTM_TT_FLAG_DECRYPTED		BIT(4)
 
 #define TTM_TT_FLAG_PRIV_POPULATED	BIT(5)
+#define TTM_TT_FLAG_PRIV_BACKED_UP	BIT(6)
 	uint32_t page_flags;
 	/** @num_pages: Number of pages in the page array. */
 	uint32_t num_pages;
@@ -105,11 +111,21 @@ struct ttm_tt {
 	dma_addr_t *dma_address;
 	/** @swap_storage: Pointer to shmem struct file for swap storage. */
 	struct file *swap_storage;
+	/**
+	 * @backup: Pointer to backup struct for backed up tts.
+	 * RFC: Could possibly be unified with @swap_storage.
+	 */
+	struct ttm_backup *backup;
 	/**
 	 * @caching: The current caching state of the pages, see enum
 	 * ttm_caching.
 	 */
 	enum ttm_caching caching;
+	/**
+	 * @restore: Partial restoration from backup state.
+	 * RFC: Incorporate in struct ttm_backup?
+	 */
+	struct ttm_pool_tt_restore *restore;
 };
 
 /**
@@ -230,6 +246,10 @@ void ttm_tt_mgr_init(unsigned long num_pages, unsigned long num_dma32_pages);
 struct ttm_kmap_iter *ttm_kmap_iter_tt_init(struct ttm_kmap_iter_tt *iter_tt,
 					    struct ttm_tt *tt);
 unsigned long ttm_tt_pages_limit(void);
+
+long ttm_tt_backup(struct ttm_device *bdev, struct ttm_tt *tt, bool purge,
+		   bool writeback);
+
 #if IS_ENABLED(CONFIG_AGP)
 #include <linux/agp_backend.h>
 
