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Commit 542c6f6d authored by Thomas Hellstrom's avatar Thomas Hellstrom Committed by Dave Airlie
Browse files

drm/ttm: Fix ttm in-kernel copying of pages with non-standard caching attributes. 



For x86 this affected highmem pages only, since they were always kmapped
cache-coherent, and this is fixed using kmap_atomic_prot().

For other architectures that may not modify the linear kernel map we
resort to vmap() for now, since kmap_atomic_prot() generally uses the
linear kernel map for lowmem pages. This of course comes with a
performance impact and should be optimized when possible.

Signed-off-by: default avatarThomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: default avatarDave Airlie <airlied@redhat.com>
parent 4677f15c

drivers/gpu/drm/ttm/ttm_bo_util.c

+52 −11
Original line number Diff line number Diff line
@@ -136,7 +136,8 @@ static int ttm_copy_io_page(void *dst, void *src, unsigned long page) 
}



static int ttm_copy_io_ttm_page(struct ttm_tt *ttm, void *src,

				unsigned long page)

				unsigned long page,

				pgprot_t prot)

{

	struct page *d = ttm_tt_get_page(ttm, page);

	void *dst;
@@ -145,17 +146,35 @@ static int ttm_copy_io_ttm_page(struct ttm_tt *ttm, void *src, 
		return -ENOMEM;



	src = (void *)((unsigned long)src + (page << PAGE_SHIFT));



#ifdef CONFIG_X86

	dst = kmap_atomic_prot(d, KM_USER0, prot);

#else

	if (prot != PAGE_KERNEL)

		dst = vmap(&d, 1, 0, prot);

	else

		dst = kmap(d);

#endif

	if (!dst)

		return -ENOMEM;



	memcpy_fromio(dst, src, PAGE_SIZE);



#ifdef CONFIG_X86

	kunmap_atomic(dst, KM_USER0);

#else

	if (prot != PAGE_KERNEL)

		vunmap(dst);

	else

		kunmap(d);

#endif



	return 0;

}



static int ttm_copy_ttm_io_page(struct ttm_tt *ttm, void *dst,

				unsigned long page)

				unsigned long page,

				pgprot_t prot)

{

	struct page *s = ttm_tt_get_page(ttm, page);

	void *src;
@@ -164,12 +183,28 @@ static int ttm_copy_ttm_io_page(struct ttm_tt *ttm, void *dst, 
		return -ENOMEM;



	dst = (void *)((unsigned long)dst + (page << PAGE_SHIFT));

#ifdef CONFIG_X86

	src = kmap_atomic_prot(s, KM_USER0, prot);

#else

	if (prot != PAGE_KERNEL)

		src = vmap(&s, 1, 0, prot);

	else

		src = kmap(s);

#endif

	if (!src)

		return -ENOMEM;



	memcpy_toio(dst, src, PAGE_SIZE);



#ifdef CONFIG_X86

	kunmap_atomic(src, KM_USER0);

#else

	if (prot != PAGE_KERNEL)

		vunmap(src);

	else

		kunmap(s);

#endif



	return 0;

}
@@ -214,11 +249,17 @@ int ttm_bo_move_memcpy(struct ttm_buffer_object *bo, 


	for (i = 0; i < new_mem->num_pages; ++i) {

		page = i * dir + add;

		if (old_iomap == NULL)

			ret = ttm_copy_ttm_io_page(ttm, new_iomap, page);

		else if (new_iomap == NULL)

			ret = ttm_copy_io_ttm_page(ttm, old_iomap, page);

		else

		if (old_iomap == NULL) {

			pgprot_t prot = ttm_io_prot(old_mem->placement,

						    PAGE_KERNEL);

			ret = ttm_copy_ttm_io_page(ttm, new_iomap, page,

						   prot);

		} else if (new_iomap == NULL) {

			pgprot_t prot = ttm_io_prot(new_mem->placement,

						    PAGE_KERNEL);

			ret = ttm_copy_io_ttm_page(ttm, old_iomap, page,

						   prot);

		} else

			ret = ttm_copy_io_page(new_iomap, old_iomap, page);

		if (ret)

			goto out1;