Basically just extracting some code duplicated in gma500, omapdrm, udl, and upcoming msm driver.
Signed-off-by: Rob Clark robdclark@gmail.com CC: Daniel Vetter daniel@ffwll.ch CC: Patrik Jakobsson patrik.r.jakobsson@gmail.com --- v1: original v2: add WARN_ON()'s for non-page-aligned sizes as suggested by Patrik Jakobsson and Daniel Vetter
drivers/gpu/drm/drm_gem.c | 103 ++++++++++++++++++++++++++++++++++++++++++++++ include/drm/drmP.h | 4 ++ 2 files changed, 107 insertions(+)
diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c index 7995466..bf299b3 100644 --- a/drivers/gpu/drm/drm_gem.c +++ b/drivers/gpu/drm/drm_gem.c @@ -408,6 +408,109 @@ 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, diff --git a/include/drm/drmP.h b/include/drm/drmP.h index fefbbda..853557a 100644 --- a/include/drm/drmP.h +++ b/include/drm/drmP.h @@ -1730,6 +1730,10 @@ void drm_gem_free_mmap_offset(struct drm_gem_object *obj); int drm_gem_create_mmap_offset(struct drm_gem_object *obj); int drm_gem_create_mmap_offset_size(struct drm_gem_object *obj, size_t size);
+struct page **drm_gem_get_pages(struct drm_gem_object *obj, gfp_t gfpmask); +void drm_gem_put_pages(struct drm_gem_object *obj, struct page **pages, + bool dirty, bool accessed); + struct drm_gem_object *drm_gem_object_lookup(struct drm_device *dev, struct drm_file *filp, u32 handle);