drm/ttm: introduce callback for ttm_tt populate & unpopulate V4

Move the page allocation and freeing to driver callback and
provide ttm code helper function for those.

Most intrusive change, is the fact that we now only fully
populate an object this simplify some of code designed around
the page fault design.

V2 Rebase on top of memory accounting overhaul
V3 New rebase on top of more memory accouting changes
V4 Rebase on top of no memory account changes (where/when is my
   delorean when i need it ?)

Signed-off-by: Jerome Glisse <jglisse@redhat.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Thomas Hellstrom <thellstrom@vmware.com>
diff --git a/drivers/gpu/drm/nouveau/nouveau_bo.c b/drivers/gpu/drm/nouveau/nouveau_bo.c
index b060fa4..f19ac42 100644
--- a/drivers/gpu/drm/nouveau/nouveau_bo.c
+++ b/drivers/gpu/drm/nouveau/nouveau_bo.c
@@ -28,6 +28,7 @@
  */
 
 #include "drmP.h"
+#include "ttm/ttm_page_alloc.h"
 
 #include "nouveau_drm.h"
 #include "nouveau_drv.h"
@@ -1050,6 +1051,8 @@
 
 struct ttm_bo_driver nouveau_bo_driver = {
 	.ttm_tt_create = &nouveau_ttm_tt_create,
+	.ttm_tt_populate = &ttm_pool_populate,
+	.ttm_tt_unpopulate = &ttm_pool_unpopulate,
 	.invalidate_caches = nouveau_bo_invalidate_caches,
 	.init_mem_type = nouveau_bo_init_mem_type,
 	.evict_flags = nouveau_bo_evict_flags,
diff --git a/drivers/gpu/drm/radeon/radeon_ttm.c b/drivers/gpu/drm/radeon/radeon_ttm.c
index af4d5f2..b1768cb 100644
--- a/drivers/gpu/drm/radeon/radeon_ttm.c
+++ b/drivers/gpu/drm/radeon/radeon_ttm.c
@@ -581,6 +581,8 @@
 
 static struct ttm_bo_driver radeon_bo_driver = {
 	.ttm_tt_create = &radeon_ttm_tt_create,
+	.ttm_tt_populate = &ttm_pool_populate,
+	.ttm_tt_unpopulate = &ttm_pool_unpopulate,
 	.invalidate_caches = &radeon_invalidate_caches,
 	.init_mem_type = &radeon_init_mem_type,
 	.evict_flags = &radeon_evict_flags,
diff --git a/drivers/gpu/drm/ttm/ttm_bo_util.c b/drivers/gpu/drm/ttm/ttm_bo_util.c
index 082fcae..60f204d 100644
--- a/drivers/gpu/drm/ttm/ttm_bo_util.c
+++ b/drivers/gpu/drm/ttm/ttm_bo_util.c
@@ -244,7 +244,7 @@
 				unsigned long page,
 				pgprot_t prot)
 {
-	struct page *d = ttm_tt_get_page(ttm, page);
+	struct page *d = ttm->pages[page];
 	void *dst;
 
 	if (!d)
@@ -281,7 +281,7 @@
 				unsigned long page,
 				pgprot_t prot)
 {
-	struct page *s = ttm_tt_get_page(ttm, page);
+	struct page *s = ttm->pages[page];
 	void *src;
 
 	if (!s)
@@ -342,6 +342,12 @@
 	if (old_iomap == NULL && ttm == NULL)
 		goto out2;
 
+	if (ttm->state == tt_unpopulated) {
+		ret = ttm->bdev->driver->ttm_tt_populate(ttm);
+		if (ret)
+			goto out1;
+	}
+
 	add = 0;
 	dir = 1;
 
@@ -502,10 +508,16 @@
 {
 	struct ttm_mem_reg *mem = &bo->mem; pgprot_t prot;
 	struct ttm_tt *ttm = bo->ttm;
-	struct page *d;
-	int i;
+	int ret;
 
 	BUG_ON(!ttm);
+
+	if (ttm->state == tt_unpopulated) {
+		ret = ttm->bdev->driver->ttm_tt_populate(ttm);
+		if (ret)
+			return ret;
+	}
+
 	if (num_pages == 1 && (mem->placement & TTM_PL_FLAG_CACHED)) {
 		/*
 		 * We're mapping a single page, and the desired
@@ -513,18 +525,9 @@
 		 */
 
 		map->bo_kmap_type = ttm_bo_map_kmap;
-		map->page = ttm_tt_get_page(ttm, start_page);
+		map->page = ttm->pages[start_page];
 		map->virtual = kmap(map->page);
 	} else {
-	    /*
-	     * Populate the part we're mapping;
-	     */
-		for (i = start_page; i < start_page + num_pages; ++i) {
-			d = ttm_tt_get_page(ttm, i);
-			if (!d)
-				return -ENOMEM;
-		}
-
 		/*
 		 * We need to use vmap to get the desired page protection
 		 * or to make the buffer object look contiguous.
diff --git a/drivers/gpu/drm/ttm/ttm_bo_vm.c b/drivers/gpu/drm/ttm/ttm_bo_vm.c
index 221b924..5441284 100644
--- a/drivers/gpu/drm/ttm/ttm_bo_vm.c
+++ b/drivers/gpu/drm/ttm/ttm_bo_vm.c
@@ -174,18 +174,23 @@
 		vma->vm_page_prot = (bo->mem.placement & TTM_PL_FLAG_CACHED) ?
 		    vm_get_page_prot(vma->vm_flags) :
 		    ttm_io_prot(bo->mem.placement, vma->vm_page_prot);
+
+		/* Allocate all page at once, most common usage */
+		if (ttm->bdev->driver->ttm_tt_populate(ttm)) {
+			retval = VM_FAULT_OOM;
+			goto out_io_unlock;
+		}
 	}
 
 	/*
 	 * Speculatively prefault a number of pages. Only error on
 	 * first page.
 	 */
-
 	for (i = 0; i < TTM_BO_VM_NUM_PREFAULT; ++i) {
 		if (bo->mem.bus.is_iomem)
 			pfn = ((bo->mem.bus.base + bo->mem.bus.offset) >> PAGE_SHIFT) + page_offset;
 		else {
-			page = ttm_tt_get_page(ttm, page_offset);
+			page = ttm->pages[page_offset];
 			if (unlikely(!page && i == 0)) {
 				retval = VM_FAULT_OOM;
 				goto out_io_unlock;
diff --git a/drivers/gpu/drm/ttm/ttm_page_alloc.c b/drivers/gpu/drm/ttm/ttm_page_alloc.c
index 0f3e6d2..8d6267e 100644
--- a/drivers/gpu/drm/ttm/ttm_page_alloc.c
+++ b/drivers/gpu/drm/ttm/ttm_page_alloc.c
@@ -855,6 +855,63 @@
 	_manager = NULL;
 }
 
+int ttm_pool_populate(struct ttm_tt *ttm)
+{
+	struct ttm_mem_global *mem_glob = ttm->glob->mem_glob;
+	unsigned i;
+	int ret;
+
+	if (ttm->state != tt_unpopulated)
+		return 0;
+
+	for (i = 0; i < ttm->num_pages; ++i) {
+		ret = ttm_get_pages(&ttm->pages[i], ttm->page_flags,
+				    ttm->caching_state, 1,
+				    &ttm->dma_address[i]);
+		if (ret != 0) {
+			ttm_pool_unpopulate(ttm);
+			return -ENOMEM;
+		}
+
+		ret = ttm_mem_global_alloc_page(mem_glob, ttm->pages[i],
+						false, false);
+		if (unlikely(ret != 0)) {
+			ttm_pool_unpopulate(ttm);
+			return -ENOMEM;
+		}
+	}
+
+	if (unlikely(ttm->page_flags & TTM_PAGE_FLAG_SWAPPED)) {
+		ret = ttm_tt_swapin(ttm);
+		if (unlikely(ret != 0)) {
+			ttm_pool_unpopulate(ttm);
+			return ret;
+		}
+	}
+
+	ttm->state = tt_unbound;
+	return 0;
+}
+EXPORT_SYMBOL(ttm_pool_populate);
+
+void ttm_pool_unpopulate(struct ttm_tt *ttm)
+{
+	unsigned i;
+
+	for (i = 0; i < ttm->num_pages; ++i) {
+		if (ttm->pages[i]) {
+			ttm_mem_global_free_page(ttm->glob->mem_glob,
+						 ttm->pages[i]);
+			ttm_put_pages(&ttm->pages[i], 1,
+				      ttm->page_flags,
+				      ttm->caching_state,
+				      ttm->dma_address);
+		}
+	}
+	ttm->state = tt_unpopulated;
+}
+EXPORT_SYMBOL(ttm_pool_unpopulate);
+
 int ttm_page_alloc_debugfs(struct seq_file *m, void *data)
 {
 	struct ttm_page_pool *p;
diff --git a/drivers/gpu/drm/ttm/ttm_tt.c b/drivers/gpu/drm/ttm/ttm_tt.c
index fbc90dc..77f0e6f 100644
--- a/drivers/gpu/drm/ttm/ttm_tt.c
+++ b/drivers/gpu/drm/ttm/ttm_tt.c
@@ -43,8 +43,6 @@
 #include "ttm/ttm_placement.h"
 #include "ttm/ttm_page_alloc.h"
 
-static int ttm_tt_swapin(struct ttm_tt *ttm);
-
 /**
  * Allocates storage for pointers to the pages that back the ttm.
  */
@@ -63,69 +61,6 @@
 	ttm->dma_address = NULL;
 }
 
-static struct page *__ttm_tt_get_page(struct ttm_tt *ttm, int index)
-{
-	struct page *p;
-	struct ttm_mem_global *mem_glob = ttm->glob->mem_glob;
-	int ret;
-
-	if (NULL == (p = ttm->pages[index])) {
-
-		ret = ttm_get_pages(&p, ttm->page_flags, ttm->caching_state, 1,
-				    &ttm->dma_address[index]);
-		if (ret != 0)
-			return NULL;
-
-		ret = ttm_mem_global_alloc_page(mem_glob, p, false, false);
-		if (unlikely(ret != 0))
-			goto out_err;
-
-		ttm->pages[index] = p;
-	}
-	return p;
-out_err:
-	ttm_put_pages(&p, 1, ttm->page_flags,
-		      ttm->caching_state, &ttm->dma_address[index]);
-	return NULL;
-}
-
-struct page *ttm_tt_get_page(struct ttm_tt *ttm, int index)
-{
-	int ret;
-
-	if (unlikely(ttm->page_flags & TTM_PAGE_FLAG_SWAPPED)) {
-		ret = ttm_tt_swapin(ttm);
-		if (unlikely(ret != 0))
-			return NULL;
-	}
-	return __ttm_tt_get_page(ttm, index);
-}
-
-int ttm_tt_populate(struct ttm_tt *ttm)
-{
-	struct page *page;
-	unsigned long i;
-	int ret;
-
-	if (ttm->state != tt_unpopulated)
-		return 0;
-
-	if (unlikely(ttm->page_flags & TTM_PAGE_FLAG_SWAPPED)) {
-		ret = ttm_tt_swapin(ttm);
-		if (unlikely(ret != 0))
-			return ret;
-	}
-
-	for (i = 0; i < ttm->num_pages; ++i) {
-		page = __ttm_tt_get_page(ttm, i);
-		if (!page)
-			return -ENOMEM;
-	}
-	ttm->state = tt_unbound;
-	return 0;
-}
-EXPORT_SYMBOL(ttm_tt_populate);
-
 #ifdef CONFIG_X86
 static inline int ttm_tt_set_page_caching(struct page *p,
 					  enum ttm_caching_state c_old,
@@ -227,21 +162,6 @@
 }
 EXPORT_SYMBOL(ttm_tt_set_placement_caching);
 
-static void ttm_tt_free_alloced_pages(struct ttm_tt *ttm)
-{
-	unsigned i;
-
-	for (i = 0; i < ttm->num_pages; ++i) {
-		if (ttm->pages[i]) {
-			ttm_mem_global_free_page(ttm->glob->mem_glob,
-						 ttm->pages[i]);
-			ttm_put_pages(&ttm->pages[i], 1, ttm->page_flags,
-				      ttm->caching_state, &ttm->dma_address[i]);
-		}
-	}
-	ttm->state = tt_unpopulated;
-}
-
 void ttm_tt_destroy(struct ttm_tt *ttm)
 {
 	if (unlikely(ttm == NULL))
@@ -252,7 +172,7 @@
 	}
 
 	if (likely(ttm->pages != NULL)) {
-		ttm_tt_free_alloced_pages(ttm);
+		ttm->bdev->driver->ttm_tt_unpopulate(ttm);
 		ttm_tt_free_page_directory(ttm);
 	}
 
@@ -307,7 +227,7 @@
 	if (ttm->state == tt_bound)
 		return 0;
 
-	ret = ttm_tt_populate(ttm);
+	ret = ttm->bdev->driver->ttm_tt_populate(ttm);
 	if (ret)
 		return ret;
 
@@ -321,7 +241,7 @@
 }
 EXPORT_SYMBOL(ttm_tt_bind);
 
-static int ttm_tt_swapin(struct ttm_tt *ttm)
+int ttm_tt_swapin(struct ttm_tt *ttm)
 {
 	struct address_space *swap_space;
 	struct file *swap_storage;
@@ -343,7 +263,7 @@
 			ret = PTR_ERR(from_page);
 			goto out_err;
 		}
-		to_page = __ttm_tt_get_page(ttm, i);
+		to_page = ttm->pages[i];
 		if (unlikely(to_page == NULL))
 			goto out_err;
 
@@ -364,7 +284,6 @@
 
 	return 0;
 out_err:
-	ttm_tt_free_alloced_pages(ttm);
 	return ret;
 }
 
@@ -416,7 +335,7 @@
 		page_cache_release(to_page);
 	}
 
-	ttm_tt_free_alloced_pages(ttm);
+	ttm->bdev->driver->ttm_tt_unpopulate(ttm);
 	ttm->swap_storage = swap_storage;
 	ttm->page_flags |= TTM_PAGE_FLAG_SWAPPED;
 	if (persistent_swap_storage)
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_buffer.c b/drivers/gpu/drm/vmwgfx/vmwgfx_buffer.c
index cc72435..3986d74 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_buffer.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_buffer.c
@@ -28,6 +28,7 @@
 #include "vmwgfx_drv.h"
 #include "ttm/ttm_bo_driver.h"
 #include "ttm/ttm_placement.h"
+#include "ttm/ttm_page_alloc.h"
 
 static uint32_t vram_placement_flags = TTM_PL_FLAG_VRAM |
 	TTM_PL_FLAG_CACHED;
@@ -334,6 +335,8 @@
 
 struct ttm_bo_driver vmw_bo_driver = {
 	.ttm_tt_create = &vmw_ttm_tt_create,
+	.ttm_tt_populate = &ttm_pool_populate,
+	.ttm_tt_unpopulate = &ttm_pool_unpopulate,
 	.invalidate_caches = vmw_invalidate_caches,
 	.init_mem_type = vmw_init_mem_type,
 	.evict_flags = vmw_evict_flags,
diff --git a/include/drm/ttm/ttm_bo_driver.h b/include/drm/ttm/ttm_bo_driver.h
index 6b8c5cd..ae06e42 100644
--- a/include/drm/ttm/ttm_bo_driver.h
+++ b/include/drm/ttm/ttm_bo_driver.h
@@ -319,6 +319,26 @@
 					struct page *dummy_read_page);
 
 	/**
+	 * ttm_tt_populate
+	 *
+	 * @ttm: The struct ttm_tt to contain the backing pages.
+	 *
+	 * Allocate all backing pages
+	 * Returns:
+	 * -ENOMEM: Out of memory.
+	 */
+	int (*ttm_tt_populate)(struct ttm_tt *ttm);
+
+	/**
+	 * ttm_tt_unpopulate
+	 *
+	 * @ttm: The struct ttm_tt to contain the backing pages.
+	 *
+	 * Free all backing page
+	 */
+	void (*ttm_tt_unpopulate)(struct ttm_tt *ttm);
+
+	/**
 	 * struct ttm_bo_driver member invalidate_caches
 	 *
 	 * @bdev: the buffer object device.
@@ -585,15 +605,6 @@
 extern int ttm_tt_bind(struct ttm_tt *ttm, struct ttm_mem_reg *bo_mem);
 
 /**
- * ttm_tt_populate:
- *
- * @ttm: The struct ttm_tt to contain the backing pages.
- *
- * Add backing pages to all of @ttm
- */
-extern int ttm_tt_populate(struct ttm_tt *ttm);
-
-/**
  * ttm_ttm_destroy:
  *
  * @ttm: The struct ttm_tt.
@@ -612,19 +623,13 @@
 extern void ttm_tt_unbind(struct ttm_tt *ttm);
 
 /**
- * ttm_ttm_destroy:
+ * ttm_tt_swapin:
  *
  * @ttm: The struct ttm_tt.
- * @index: Index of the desired page.
  *
- * Return a pointer to the struct page backing @ttm at page
- * index @index. If the page is unpopulated, one will be allocated to
- * populate that index.
- *
- * Returns:
- * NULL on OOM.
+ * Swap in a previously swap out ttm_tt.
  */
-extern struct page *ttm_tt_get_page(struct ttm_tt *ttm, int index);
+extern int ttm_tt_swapin(struct ttm_tt *ttm);
 
 /**
  * ttm_tt_cache_flush:
diff --git a/include/drm/ttm/ttm_page_alloc.h b/include/drm/ttm/ttm_page_alloc.h
index fe61c8d..18deeee 100644
--- a/include/drm/ttm/ttm_page_alloc.h
+++ b/include/drm/ttm/ttm_page_alloc.h
@@ -68,6 +68,24 @@
 void ttm_page_alloc_fini(void);
 
 /**
+ * ttm_pool_populate:
+ *
+ * @ttm: The struct ttm_tt to contain the backing pages.
+ *
+ * Add backing pages to all of @ttm
+ */
+extern int ttm_pool_populate(struct ttm_tt *ttm);
+
+/**
+ * ttm_pool_unpopulate:
+ *
+ * @ttm: The struct ttm_tt which to free backing pages.
+ *
+ * Free all pages of @ttm
+ */
+extern void ttm_pool_unpopulate(struct ttm_tt *ttm);
+
+/**
  * Output the state of pools to debugfs file
  */
 extern int ttm_page_alloc_debugfs(struct seq_file *m, void *data);