drm: Update drm_addmap and drm_mmap to use PAT WC instead of MTRRs

Previously, DRM_FRAME_BUFFER mappings, as well as DRM_REGISTERS
mappings with DRM_WRITE_COMBINING set, resulted in an unconditional
MTRR being added but the actual mappings being created as UC-.

Now these mappings have the MTRR added only if needed, but they will
be mapped with pgprot_writecombine.

The non-WC DRM_REGISTERS case now uses pgprot_noncached instead of
hardcoding the bit twiddling.

The DRM_AGP case is unchanged for now.

[airlied: fix ppc build]
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Dave Airlie <airlied@redhat.com>

diff --git a/drivers/gpu/drm/drm_bufs.c b/drivers/gpu/drm/drm_bufs.c
index 0128147..0190fce 100644 (file)
--- a/drivers/gpu/drm/drm_bufs.c
+++ b/drivers/gpu/drm/drm_bufs.c
@@ -210,12 +210,16 @@ static int drm_addmap_core(struct drm_device * dev, resource_size_t offset,
                if (drm_core_has_MTRR(dev)) {
                        if (map->type == _DRM_FRAME_BUFFER ||
                            (map->flags & _DRM_WRITE_COMBINING)) {
-                               map->mtrr = mtrr_add(map->offset, map->size,
-                                                    MTRR_TYPE_WRCOMB, 1);
+                               map->mtrr =
+                                       arch_phys_wc_add(map->offset, map->size);
                        }
                }
                if (map->type == _DRM_REGISTERS) {
-                       map->handle = ioremap(map->offset, map->size);
+                       if (map->flags & _DRM_WRITE_COMBINING)
+                               map->handle = ioremap_wc(map->offset,
+                                                        map->size);
+                       else
+                               map->handle = ioremap(map->offset, map->size);
                        if (!map->handle) {
                                kfree(map);
                                return -ENOMEM;
@@ -451,11 +455,8 @@ int drm_rmmap_locked(struct drm_device *dev, struct drm_local_map *map)
                iounmap(map->handle);
                /* FALLTHROUGH */
        case _DRM_FRAME_BUFFER:
-               if (drm_core_has_MTRR(dev) && map->mtrr >= 0) {
-                       int retcode;
-                       retcode = mtrr_del(map->mtrr, map->offset, map->size);
-                       DRM_DEBUG("mtrr_del=%d\n", retcode);
-               }
+               if (drm_core_has_MTRR(dev))
+                       arch_phys_wc_del(map->mtrr);
                break;
        case _DRM_SHM:
                vfree(map->handle);

diff --git a/drivers/gpu/drm/drm_vm.c b/drivers/gpu/drm/drm_vm.c
index 1d4f7c9..43e7825 100644 (file)
--- a/drivers/gpu/drm/drm_vm.c
+++ b/drivers/gpu/drm/drm_vm.c
@@ -43,18 +43,22 @@
 static void drm_vm_open(struct vm_area_struct *vma);
 static void drm_vm_close(struct vm_area_struct *vma);
 
-static pgprot_t drm_io_prot(uint32_t map_type, struct vm_area_struct *vma)
+static pgprot_t drm_io_prot(struct drm_local_map *map,
+                           struct vm_area_struct *vma)
 {
        pgprot_t tmp = vm_get_page_prot(vma->vm_flags);
 
 #if defined(__i386__) || defined(__x86_64__)
-       if (boot_cpu_data.x86 > 3 && map_type != _DRM_AGP) {
-               pgprot_val(tmp) |= _PAGE_PCD;
-               pgprot_val(tmp) &= ~_PAGE_PWT;
+       if (map->type != _DRM_AGP) {
+               if (map->type == _DRM_FRAME_BUFFER ||
+                   map->flags & _DRM_WRITE_COMBINING)
+                       tmp = pgprot_writecombine(tmp);
+               else
+                       tmp = pgprot_noncached(tmp);
        }
 #elif defined(__powerpc__)
        pgprot_val(tmp) |= _PAGE_NO_CACHE;
-       if (map_type == _DRM_REGISTERS)
+       if (map->type == _DRM_REGISTERS)
                pgprot_val(tmp) |= _PAGE_GUARDED;
 #elif defined(__ia64__)
        if (efi_range_is_wc(vma->vm_start, vma->vm_end -
@@ -250,13 +254,8 @@ static void drm_vm_shm_close(struct vm_area_struct *vma)
                        switch (map->type) {
                        case _DRM_REGISTERS:
                        case _DRM_FRAME_BUFFER:
-                               if (drm_core_has_MTRR(dev) && map->mtrr >= 0) {
-                                       int retcode;
-                                       retcode = mtrr_del(map->mtrr,
-                                                          map->offset,
-                                                          map->size);
-                                       DRM_DEBUG("mtrr_del = %d\n", retcode);
-                               }
+                               if (drm_core_has_MTRR(dev))
+                                       arch_phys_wc_del(map->mtrr);
                                iounmap(map->handle);
                                break;
                        case _DRM_SHM:
@@ -618,7 +617,7 @@ int drm_mmap_locked(struct file *filp, struct vm_area_struct *vma)
        case _DRM_REGISTERS:
                offset = drm_core_get_reg_ofs(dev);
                vma->vm_flags |= VM_IO; /* not in core dump */
-               vma->vm_page_prot = drm_io_prot(map->type, vma);
+               vma->vm_page_prot = drm_io_prot(map, vma);
                if (io_remap_pfn_range(vma, vma->vm_start,
                                       (map->offset + offset) >> PAGE_SHIFT,
                                       vma->vm_end - vma->vm_start,