drm/ttm: Use VM_PFNMAP for shared bo maps
VM_PFNMAP is faster than VM_MIXEDMAP due to reduced page administration so
use it for shared maps where we don't have any Copy-On-Write pages. For
private maps, we continue to use VM_MIXEDMAP.
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Jakob Bornecrantz <jakob@vmware.com>
diff --git a/drivers/gpu/drm/ttm/ttm_bo_vm.c b/drivers/gpu/drm/ttm/ttm_bo_vm.c
index b249ab9..cdda784 100644
--- a/drivers/gpu/drm/ttm/ttm_bo_vm.c
+++ b/drivers/gpu/drm/ttm/ttm_bo_vm.c
@@ -220,7 +220,11 @@
pfn = page_to_pfn(page);
}
- ret = vm_insert_mixed(&cvma, address, pfn);
+ if (vma->vm_flags & VM_MIXEDMAP)
+ ret = vm_insert_mixed(&cvma, address, pfn);
+ else
+ ret = vm_insert_pfn(&cvma, address, pfn);
+
/*
* Somebody beat us to this PTE or prefaulting to
* an already populated PTE, or prefaulting error.
@@ -319,7 +323,14 @@
*/
vma->vm_private_data = bo;
- vma->vm_flags |= VM_IO | VM_MIXEDMAP | VM_DONTEXPAND | VM_DONTDUMP;
+
+ /*
+ * PFNMAP is faster than MIXEDMAP due to reduced page
+ * administration. So use MIXEDMAP only if private VMA, where
+ * we need to support COW.
+ */
+ vma->vm_flags |= (vma->vm_flags & VM_SHARED) ? VM_PFNMAP : VM_MIXEDMAP;
+ vma->vm_flags |= VM_IO | VM_DONTEXPAND | VM_DONTDUMP;
return 0;
out_unref:
ttm_bo_unref(&bo);
@@ -334,7 +345,8 @@
vma->vm_ops = &ttm_bo_vm_ops;
vma->vm_private_data = ttm_bo_reference(bo);
- vma->vm_flags |= VM_IO | VM_MIXEDMAP | VM_DONTEXPAND;
+ vma->vm_flags |= (vma->vm_flags & VM_SHARED) ? VM_PFNMAP : VM_MIXEDMAP;
+ vma->vm_flags |= VM_IO | VM_DONTEXPAND;
return 0;
}
EXPORT_SYMBOL(ttm_fbdev_mmap);