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, 12 insertions, 10 deletions

diff --git a/drivers/gpu/drm/drm_vm.c b/drivers/gpu/drm/drm_vm.c
index 0d8bbd72ec55..22f76567ac7d 100644
--- a/drivers/gpu/drm/drm_vm.c
+++ b/drivers/gpu/drm/drm_vm.c
@@ -115,9 +115,9 @@ static int drm_do_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
                  * Using vm_pgoff as a selector forces us to use this unusual
                  * addressing scheme.
                  */
-                unsigned long offset = (unsigned long)vmf->virtual_address -
-                                                                vma->vm_start;
-                unsigned long baddr = map->offset + offset;
+                resource_size_t offset = (unsigned long)vmf->virtual_address -
+                        vma->vm_start;
+                resource_size_t baddr = map->offset + offset;
                 struct drm_agp_mem *agpmem;
                 struct page *page;
 
@@ -149,8 +149,10 @@ static int drm_do_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
                 vmf->page = page;
 
                 DRM_DEBUG
-                    ("baddr = 0x%lx page = 0x%p, offset = 0x%lx, count=%d\n",
-                     baddr, __va(agpmem->memory->memory[offset]), offset,
+                    ("baddr = 0x%llx page = 0x%p, offset = 0x%llx, count=%d\n",
+                     (unsigned long long)baddr,
+                     __va(agpmem->memory->memory[offset]),
+                     (unsigned long long)offset,
                      page_count(page));
                 return 0;
         }
@@ -512,14 +514,14 @@ static int drm_mmap_dma(struct file *filp, struct vm_area_struct *vma)
         return 0;
 }
 
-unsigned long drm_core_get_map_ofs(struct drm_local_map * map)
+resource_size_t drm_core_get_map_ofs(struct drm_local_map * map)
 {
         return map->offset;
 }
 
 EXPORT_SYMBOL(drm_core_get_map_ofs);
 
-unsigned long drm_core_get_reg_ofs(struct drm_device *dev)
+resource_size_t drm_core_get_reg_ofs(struct drm_device *dev)
 {
 #ifdef __alpha__
         return dev->hose->dense_mem_base - dev->hose->mem_space->start;
@@ -548,7 +550,7 @@ int drm_mmap_locked(struct file *filp, struct vm_area_struct *vma)
         struct drm_file *priv = filp->private_data;
         struct drm_device *dev = priv->minor->dev;
         struct drm_local_map *map = NULL;
-        unsigned long offset = 0;
+        resource_size_t offset = 0;
         struct drm_hash_item *hash;
 
         DRM_DEBUG("start = 0x%lx, end = 0x%lx, page offset = 0x%lx\n",
@@ -623,9 +625,9 @@ int drm_mmap_locked(struct file *filp, struct vm_area_struct *vma)
                                        vma->vm_page_prot))
                         return -EAGAIN;
                 DRM_DEBUG("   Type = %d; start = 0x%lx, end = 0x%lx,"
-                          " offset = 0x%lx\n",
+                          " offset = 0x%llx\n",
                           map->type,
-                          vma->vm_start, vma->vm_end, map->offset + offset);
+                          vma->vm_start, vma->vm_end, (unsigned long long)(map->offset + offset));
                 vma->vm_ops = &drm_vm_ops;
                 break;
         case _DRM_CONSISTENT: