From ff47eaf24d01b5753e4964b10c606e0d711b143e Mon Sep 17 00:00:00 2001 From: Andy Lutomirski Date: Mon, 13 May 2013 23:58:42 +0000 Subject: 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 Signed-off-by: Andy Lutomirski Signed-off-by: Dave Airlie --- drivers/gpu/drm/drm_vm.c | 25 ++++++++++++------------- 1 file changed, 12 insertions(+), 13 deletions(-) (limited to 'drivers/gpu/drm/drm_vm.c') diff --git a/drivers/gpu/drm/drm_vm.c b/drivers/gpu/drm/drm_vm.c index 1d4f7c9fe661..43e7825d3717 100644 --- 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, -- cgit From f435046d38af631920b299455db9e95dfc06d055 Mon Sep 17 00:00:00 2001 From: Andy Lutomirski Date: Mon, 13 May 2013 23:58:43 +0000 Subject: drm, agpgart: Use pgprot_writecombine for AGP maps and make the MTRR optional I'm not sure I understand the intent of the previous behavior. mmap on /dev/agpgart and DRM_AGP maps had no cache flags set, so they would be fully cacheable. But the DRM code (most of the time) would add a write-combining MTRR that would change the effective memory type to WC. The new behavior just requests WC explicitly for all AGP maps. If there is any code out there that expects cacheable access to the AGP aperture (because the drm driver doesn't request an MTRR or because it's using /dev/agpgart directly), then it will now end up with a UC or WC mapping, depending on the architecture and PAT availability. But cacheable access to the aperture seems like it's asking for trouble, because, AIUI, the aperture is an alias of RAM. Reviewed-by: Daniel Vetter Signed-off-by: Andy Lutomirski Signed-off-by: Dave Airlie --- drivers/gpu/drm/drm_vm.c | 11 ++++------- 1 file changed, 4 insertions(+), 7 deletions(-) (limited to 'drivers/gpu/drm/drm_vm.c') diff --git a/drivers/gpu/drm/drm_vm.c b/drivers/gpu/drm/drm_vm.c index 43e7825d3717..1575694ccaca 100644 --- a/drivers/gpu/drm/drm_vm.c +++ b/drivers/gpu/drm/drm_vm.c @@ -49,13 +49,10 @@ static pgprot_t drm_io_prot(struct drm_local_map *map, pgprot_t tmp = vm_get_page_prot(vma->vm_flags); #if defined(__i386__) || defined(__x86_64__) - 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); - } + if (map->type == _DRM_REGISTERS && !(map->flags & _DRM_WRITE_COMBINING)) + tmp = pgprot_noncached(tmp); + else + tmp = pgprot_writecombine(tmp); #elif defined(__powerpc__) pgprot_val(tmp) |= _PAGE_NO_CACHE; if (map->type == _DRM_REGISTERS) -- cgit From fdcdec06a3027ab227b1780c353acece65c8e970 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Mon, 24 Jun 2013 06:26:50 +1000 Subject: drm_vm: drop explicit VM_IO setting io_remap_pfn_range already sets this internally. Signed-off-by: Al Viro Signed-off-by: Dave Airlie --- drivers/gpu/drm/drm_vm.c | 1 - 1 file changed, 1 deletion(-) (limited to 'drivers/gpu/drm/drm_vm.c') diff --git a/drivers/gpu/drm/drm_vm.c b/drivers/gpu/drm/drm_vm.c index 1575694ccaca..feb20035b2c4 100644 --- a/drivers/gpu/drm/drm_vm.c +++ b/drivers/gpu/drm/drm_vm.c @@ -613,7 +613,6 @@ int drm_mmap_locked(struct file *filp, struct vm_area_struct *vma) case _DRM_FRAME_BUFFER: 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, vma); if (io_remap_pfn_range(vma, vma->vm_start, (map->offset + offset) >> PAGE_SHIFT, -- cgit