drm: Make drm_local_map use a resource_size_t offset

This changes drm_local_map to use a resource_size for its "offset"
member instead of an unsigned long, thus allowing 32-bit machines
with a >32-bit physical address space to be able to store there
their register or framebuffer addresses when those are above 4G,
such as when using a PCI video card on a recent AMCC 440 SoC.

This patch isn't as "trivial" as it sounds: A few functions needed
to have some unsigned long/int changed to resource_size_t and a few
printk's had to be adjusted.

But also, because userspace isn't capable of passing such offsets,
I had to modify drm_find_matching_map() to ignore the offset passed
in for maps of type _DRM_FRAMEBUFFER or _DRM_REGISTERS.

If we ever support multiple _DRM_FRAMEBUFFER or _DRM_REGISTERS maps
for a given device, we might have to change that trick, but I don't
think that happens on any current driver.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Dave Airlie <airlied@linux.ie>

1 files changed, 28 insertions, 9 deletions

diff --git a/drivers/gpu/drm/drm_bufs.c b/drivers/gpu/drm/drm_bufs.c
index 1b8dbd5961bc..cddea1a2472c 100644
--- a/drivers/gpu/drm/drm_bufs.c
+++ b/drivers/gpu/drm/drm_bufs.c
@@ -54,11 +54,29 @@ static struct drm_map_list *drm_find_matching_map(struct drm_device *dev,
 {
         struct drm_map_list *entry;
         list_for_each_entry(entry, &dev->maplist, head) {
-                if (entry->map && (entry->master == dev->primary->master) && (map->type == entry->map->type) &&
-                    ((entry->map->offset == map->offset) ||
-                     ((map->type == _DRM_SHM) && (map->flags&_DRM_CONTAINS_LOCK)))) {
+                /*
+                 * Because the kernel-userspace ABI is fixed at a 32-bit offset
+                 * while PCI resources may live above that, we ignore the map
+                 * offset for maps of type _DRM_FRAMEBUFFER or _DRM_REGISTERS.
+                 * It is assumed that each driver will have only one resource of
+                 * each type.
+                 */
+                if (!entry->map ||
+                    map->type != entry->map->type ||
+                    entry->master != dev->primary->master)
+                        continue;
+                switch (map->type) {
+                case _DRM_SHM:
+                        if (map->flags != _DRM_CONTAINS_LOCK)
+                                break;
+                case _DRM_REGISTERS:
+                case _DRM_FRAME_BUFFER:
                         return entry;
+                default: /* Make gcc happy */
+                        ;
                 }
+                if (entry->map->offset == map->offset)
+                        return entry;
         }
 
         return NULL;
@@ -96,7 +114,7 @@ static int drm_map_handle(struct drm_device *dev, struct drm_hash_item *hash,
  * type.  Adds the map to the map list drm_device::maplist. Adds MTRR's where
  * applicable and if supported by the kernel.
  */
-static int drm_addmap_core(struct drm_device * dev, unsigned int offset,
+static int drm_addmap_core(struct drm_device * dev, resource_size_t offset,
                            unsigned int size, enum drm_map_type type,
                            enum drm_map_flags flags,
                            struct drm_map_list ** maplist)
@@ -124,9 +142,9 @@ static int drm_addmap_core(struct drm_device * dev, unsigned int offset,
                 drm_free(map, sizeof(*map), DRM_MEM_MAPS);
                 return -EINVAL;
         }
-        DRM_DEBUG("offset = 0x%08lx, size = 0x%08lx, type = %d\n",
-                  map->offset, map->size, map->type);
-        if ((map->offset & (~PAGE_MASK)) || (map->size & (~PAGE_MASK))) {
+        DRM_DEBUG("offset = 0x%08llx, size = 0x%08lx, type = %d\n",
+                  (unsigned long long)map->offset, map->size, map->type);
+        if ((map->offset & (~(resource_size_t)PAGE_MASK)) || (map->size & (~PAGE_MASK))) {
                 drm_free(map, sizeof(*map), DRM_MEM_MAPS);
                 return -EINVAL;
         }
@@ -254,7 +272,8 @@ static int drm_addmap_core(struct drm_device * dev, unsigned int offset,
                         drm_free(map, sizeof(*map), DRM_MEM_MAPS);
                         return -EPERM;
                 }
-                DRM_DEBUG("AGP offset = 0x%08lx, size = 0x%08lx\n", map->offset, map->size);
+                DRM_DEBUG("AGP offset = 0x%08llx, size = 0x%08lx\n",
+                          (unsigned long long)map->offset, map->size);
 
                 break;
         case _DRM_GEM:
@@ -322,7 +341,7 @@ static int drm_addmap_core(struct drm_device * dev, unsigned int offset,
         return 0;
         }
 
-int drm_addmap(struct drm_device * dev, unsigned int offset,
+int drm_addmap(struct drm_device * dev, resource_size_t offset,
                unsigned int size, enum drm_map_type type,
                enum drm_map_flags flags, struct drm_local_map ** map_ptr)
 {