diff options
Diffstat (limited to 'drivers/staging/omapdrm/omap_gem_helpers.c')
-rw-r--r-- | drivers/staging/omapdrm/omap_gem_helpers.c | 114 |
1 files changed, 114 insertions, 0 deletions
diff --git a/drivers/staging/omapdrm/omap_gem_helpers.c b/drivers/staging/omapdrm/omap_gem_helpers.c new file mode 100644 index 0000000..1cfc12d --- /dev/null +++ b/drivers/staging/omapdrm/omap_gem_helpers.c @@ -0,0 +1,114 @@ +/* + * drivers/staging/omapdrm/omap_gem_helpers.c + * + * Copyright (C) 2011 Texas Instruments + * Author: Rob Clark <rob.clark@linaro.org> + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 as published by + * the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + * + * You should have received a copy of the GNU General Public License along with + * this program. If not, see <http://www.gnu.org/licenses/>. + */ + +/* temporary copy of drm_gem_{get,put}_pages() until the + * "drm/gem: add functions to get/put pages" patch is merged.. + */ + +#include <linux/module.h> +#include <linux/types.h> +#include <linux/shmem_fs.h> + +#include <drm/drmP.h> + +/** + * drm_gem_get_pages - helper to allocate backing pages for a GEM object + * @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 = obj->filp->f_path.dentry->d_inode; + mapping = inode->i_mapping; + + 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_PTR(PTR_ERR(p)); +} + +/** + * drm_gem_put_pages - helper to free backing pages for a GEM object + * @obj: obj in question + * @pages: pages to free + */ +void _drm_gem_put_pages(struct drm_gem_object *obj, struct page **pages, + bool dirty, bool accessed) +{ + int i, npages; + + 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); +} |