diff options
| -rw-r--r-- | drivers/gpu/drm/drm_bufs.c | 35 |
1 files changed, 31 insertions, 4 deletions
diff --git a/drivers/gpu/drm/drm_bufs.c b/drivers/gpu/drm/drm_bufs.c index cddea1a2472..6d80d17f1e9 100644 --- a/drivers/gpu/drm/drm_bufs.c +++ b/drivers/gpu/drm/drm_bufs.c @@ -34,6 +34,8 @@ */ #include <linux/vmalloc.h> +#include <linux/log2.h> +#include <asm/shmparam.h> #include "drmP.h" resource_size_t drm_get_resource_start(struct drm_device *dev, unsigned int resource) @@ -83,9 +85,11 @@ static struct drm_map_list *drm_find_matching_map(struct drm_device *dev, } static int drm_map_handle(struct drm_device *dev, struct drm_hash_item *hash, - unsigned long user_token, int hashed_handle) + unsigned long user_token, int hashed_handle, int shm) { - int use_hashed_handle; + int use_hashed_handle, shift; + unsigned long add; + #if (BITS_PER_LONG == 64) use_hashed_handle = ((user_token & 0xFFFFFFFF00000000UL) || hashed_handle); #elif (BITS_PER_LONG == 32) @@ -101,9 +105,31 @@ static int drm_map_handle(struct drm_device *dev, struct drm_hash_item *hash, if (ret != -EINVAL) return ret; } + + shift = 0; + add = DRM_MAP_HASH_OFFSET >> PAGE_SHIFT; + if (shm && (SHMLBA > PAGE_SIZE)) { + int bits = ilog2(SHMLBA >> PAGE_SHIFT) + 1; + + /* For shared memory, we have to preserve the SHMLBA + * bits of the eventual vma->vm_pgoff value during + * mmap(). Otherwise we run into cache aliasing problems + * on some platforms. On these platforms, the pgoff of + * a mmap() request is used to pick a suitable virtual + * address for the mmap() region such that it will not + * cause cache aliasing problems. + * + * Therefore, make sure the SHMLBA relevant bits of the + * hash value we use are equal to those in the original + * kernel virtual address. + */ + shift = bits; + add |= ((user_token >> PAGE_SHIFT) & ((1UL << bits) - 1UL)); + } + return drm_ht_just_insert_please(&dev->map_hash, hash, user_token, 32 - PAGE_SHIFT - 3, - 0, DRM_MAP_HASH_OFFSET >> PAGE_SHIFT); + shift, add); } /** @@ -323,7 +349,8 @@ static int drm_addmap_core(struct drm_device * dev, resource_size_t offset, /* We do it here so that dev->struct_mutex protects the increment */ user_token = (map->type == _DRM_SHM) ? (unsigned long)map->handle : map->offset; - ret = drm_map_handle(dev, &list->hash, user_token, 0); + ret = drm_map_handle(dev, &list->hash, user_token, 0, + (map->type == _DRM_SHM)); if (ret) { if (map->type == _DRM_REGISTERS) iounmap(map->handle); |