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.
Signed-off-by: Andy Lutomirski luto@amacapital.net ---
Unlike v1, this should work well even for drivers that call drmAddMap from userspace. I didn't understand how the flags were supposed to work last time around.
drivers/gpu/drm/drm_bufs.c | 17 +++++++++-------- drivers/gpu/drm/drm_vm.c | 23 +++++++++++------------ 2 files changed, 20 insertions(+), 20 deletions(-)
diff --git a/drivers/gpu/drm/drm_bufs.c b/drivers/gpu/drm/drm_bufs.c index 0128147..0190fce 100644 --- 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 db7bd29..163f436 100644 --- a/drivers/gpu/drm/drm_vm.c +++ b/drivers/gpu/drm/drm_vm.c @@ -43,14 +43,18 @@ 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; @@ -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: @@ -617,7 +616,7 @@ 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,