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authorRob Clark <robdclark@gmail.com>2013-08-07 13:41:24 -0400
committerChanho Park <chanho61.park@samsung.com>2014-11-21 19:13:42 +0900
commitb76be4ede92521b826622ff4fed8a59962fca647 (patch)
tree08967b5943eec66911939bc3eb75ab476cbcda11 /drivers/gpu/drm
parent7bde9c1f036e959cb656f1a8d98bd7be8e5d6614 (diff)
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drm/gem: add shmem get/put page helpers
Basically just extracting some code duplicated in gma500, omapdrm, udl, and upcoming msm driver. Signed-off-by: Rob Clark <robdclark@gmail.com> Signed-off-by: Dave Airlie <airlied@redhat.com>
Diffstat (limited to 'drivers/gpu/drm')
-rw-r--r--drivers/gpu/drm/drm_gem.c103
1 files changed, 103 insertions, 0 deletions
diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c
index 6124a591501..d0c247ac271 100644
--- a/drivers/gpu/drm/drm_gem.c
+++ b/drivers/gpu/drm/drm_gem.c
@@ -421,6 +421,109 @@ int drm_gem_create_mmap_offset(struct drm_gem_object *obj)
}
EXPORT_SYMBOL(drm_gem_create_mmap_offset);
+/**
+ * drm_gem_get_pages - helper to allocate backing pages for a GEM object
+ * from shmem
+ * @obj: obj in question
+ * @gfpmask: gfp mask of requested pages
+ */
+struct page **drm_gem_get_pages(struct drm_gem_object *obj, gfp_t gfpmask)
+{
+ struct inode *inode;
+ struct address_space *mapping;
+ struct page *p, **pages;
+ int i, npages;
+
+ /* This is the shared memory object that backs the GEM resource */
+ inode = file_inode(obj->filp);
+ mapping = inode->i_mapping;
+
+ /* We already BUG_ON() for non-page-aligned sizes in
+ * drm_gem_object_init(), so we should never hit this unless
+ * driver author is doing something really wrong:
+ */
+ WARN_ON((obj->size & (PAGE_SIZE - 1)) != 0);
+
+ npages = obj->size >> PAGE_SHIFT;
+
+ pages = drm_malloc_ab(npages, sizeof(struct page *));
+ if (pages == NULL)
+ return ERR_PTR(-ENOMEM);
+
+ gfpmask |= mapping_gfp_mask(mapping);
+
+ for (i = 0; i < npages; i++) {
+ p = shmem_read_mapping_page_gfp(mapping, i, gfpmask);
+ if (IS_ERR(p))
+ goto fail;
+ pages[i] = p;
+
+ /* There is a hypothetical issue w/ drivers that require
+ * buffer memory in the low 4GB.. if the pages are un-
+ * pinned, and swapped out, they can end up swapped back
+ * in above 4GB. If pages are already in memory, then
+ * shmem_read_mapping_page_gfp will ignore the gfpmask,
+ * even if the already in-memory page disobeys the mask.
+ *
+ * It is only a theoretical issue today, because none of
+ * the devices with this limitation can be populated with
+ * enough memory to trigger the issue. But this BUG_ON()
+ * is here as a reminder in case the problem with
+ * shmem_read_mapping_page_gfp() isn't solved by the time
+ * it does become a real issue.
+ *
+ * See this thread: http://lkml.org/lkml/2011/7/11/238
+ */
+ BUG_ON((gfpmask & __GFP_DMA32) &&
+ (page_to_pfn(p) >= 0x00100000UL));
+ }
+
+ return pages;
+
+fail:
+ while (i--)
+ page_cache_release(pages[i]);
+
+ drm_free_large(pages);
+ return ERR_CAST(p);
+}
+EXPORT_SYMBOL(drm_gem_get_pages);
+
+/**
+ * drm_gem_put_pages - helper to free backing pages for a GEM object
+ * @obj: obj in question
+ * @pages: pages to free
+ * @dirty: if true, pages will be marked as dirty
+ * @accessed: if true, the pages will be marked as accessed
+ */
+void drm_gem_put_pages(struct drm_gem_object *obj, struct page **pages,
+ bool dirty, bool accessed)
+{
+ int i, npages;
+
+ /* We already BUG_ON() for non-page-aligned sizes in
+ * drm_gem_object_init(), so we should never hit this unless
+ * driver author is doing something really wrong:
+ */
+ WARN_ON((obj->size & (PAGE_SIZE - 1)) != 0);
+
+ npages = obj->size >> PAGE_SHIFT;
+
+ for (i = 0; i < npages; i++) {
+ if (dirty)
+ set_page_dirty(pages[i]);
+
+ if (accessed)
+ mark_page_accessed(pages[i]);
+
+ /* Undo the reference we took when populating the table */
+ page_cache_release(pages[i]);
+ }
+
+ drm_free_large(pages);
+}
+EXPORT_SYMBOL(drm_gem_put_pages);
+
/** Returns a reference to the object named by the handle. */
struct drm_gem_object *
drm_gem_object_lookup(struct drm_device *dev, struct drm_file *filp,