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Commit 7dfe8b61 authored by Thomas Hellstrom's avatar Thomas Hellstrom
Browse files

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: default avatarThomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: default avatarJakob Bornecrantz <jakob@vmware.com>
parent 859ae233

drivers/gpu/drm/ttm/ttm_bo_vm.c

+15 −3
Original line number Diff line number Diff line
@@ -220,7 +220,11 @@ static int ttm_bo_vm_fault(struct vm_area_struct *vma, struct vm_fault *vmf) 
			pfn = page_to_pfn(page);

		}



		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 @@ int ttm_bo_mmap(struct file *filp, struct vm_area_struct *vma, 
	 */



	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 @@ int ttm_fbdev_mmap(struct vm_area_struct *vma, struct ttm_buffer_object *bo) 


	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);