[PATCH 3/7] drm: Update drm_addmap and drm_mmap to use PAT WC instead of MTRRs

From: Andy Lutomirski
Date: Fri May 03 2013 - 19:01:56 EST


Signed-off-by: Andy Lutomirski <luto@xxxxxxxxxxxxxx>
---

This needs careful review. I don't really know what this code does, nor
do I have the hardware. (I don't understand AGP and the associated
caching implications.)

drivers/gpu/drm/drm_bufs.c | 11 ++++-------
drivers/gpu/drm/drm_vm.c | 13 +++++++------
2 files changed, 11 insertions(+), 13 deletions(-)

diff --git a/drivers/gpu/drm/drm_bufs.c b/drivers/gpu/drm/drm_bufs.c
index 0128147..0ae9cbb 100644
--- a/drivers/gpu/drm/drm_bufs.c
+++ b/drivers/gpu/drm/drm_bufs.c
@@ -210,8 +210,8 @@ 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 =
+ drm_mtrr_add_wc(map->offset, map->size);
}
}
if (map->type == _DRM_REGISTERS) {
@@ -451,11 +451,8 @@ 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))
+ drm_mtrr_del_wc(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 db7bd29..b255fd7 100644
--- a/drivers/gpu/drm/drm_vm.c
+++ b/drivers/gpu/drm/drm_vm.c
@@ -43,15 +43,16 @@
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->flags & _DRM_WRITE_COMBINING)
+ tmp = pgprot_writecombine(tmp);
+ else if (map->type != _DRM_AGP)
+ tmp = pgprot_noncached(tmp);
#elif defined(__powerpc__)
pgprot_val(tmp) |= _PAGE_NO_CACHE;
if (map_type == _DRM_REGISTERS)
@@ -617,7 +618,7 @@ 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,
--
1.8.1.4

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