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Commit 99a03df5 authored by Chris Wilson's avatar Chris Wilson Committed by Eric Anholt
Browse files

drm/i915: Use non-atomic kmap for slow copy paths 



As we do not have a requirement to be atomic and avoid sleeping whilst
performing the slow copy for shmem based pread and pwrite, we can use
kmap instead, thus simplifying the code.

Signed-off-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: default avatarEric Anholt <eric@anholt.net>
parent 9b8c4a0b

drivers/gpu/drm/i915/i915_gem.c

+30 −52
Original line number Diff line number Diff line
@@ -167,7 +167,7 @@ static int i915_gem_object_needs_bit17_swizzle(struct drm_gem_object *obj) 
		obj_priv->tiling_mode != I915_TILING_NONE;

}



static inline int

static inline void

slow_shmem_copy(struct page *dst_page,

		int dst_offset,

		struct page *src_page,
@@ -176,25 +176,16 @@ slow_shmem_copy(struct page *dst_page, 
{

	char *dst_vaddr, *src_vaddr;



	dst_vaddr = kmap_atomic(dst_page, KM_USER0);

	if (dst_vaddr == NULL)

		return -ENOMEM;



	src_vaddr = kmap_atomic(src_page, KM_USER1);

	if (src_vaddr == NULL) {

		kunmap_atomic(dst_vaddr, KM_USER0);

		return -ENOMEM;

	}

	dst_vaddr = kmap(dst_page);

	src_vaddr = kmap(src_page);



	memcpy(dst_vaddr + dst_offset, src_vaddr + src_offset, length);



	kunmap_atomic(src_vaddr, KM_USER1);

	kunmap_atomic(dst_vaddr, KM_USER0);



	return 0;

	kunmap(src_page);

	kunmap(dst_page);

}



static inline int

static inline void

slow_shmem_bit17_copy(struct page *gpu_page,

		      int gpu_offset,

		      struct page *cpu_page,
@@ -214,15 +205,8 @@ slow_shmem_bit17_copy(struct page *gpu_page, 
					       cpu_page, cpu_offset, length);

	}



	gpu_vaddr = kmap_atomic(gpu_page, KM_USER0);

	if (gpu_vaddr == NULL)

		return -ENOMEM;



	cpu_vaddr = kmap_atomic(cpu_page, KM_USER1);

	if (cpu_vaddr == NULL) {

		kunmap_atomic(gpu_vaddr, KM_USER0);

		return -ENOMEM;

	}

	gpu_vaddr = kmap(gpu_page);

	cpu_vaddr = kmap(cpu_page);



	/* Copy the data, XORing A6 with A17 (1). The user already knows he's

	 * XORing with the other bits (A9 for Y, A9 and A10 for X)
@@ -246,10 +230,8 @@ slow_shmem_bit17_copy(struct page *gpu_page, 
		length -= this_length;

	}



	kunmap_atomic(cpu_vaddr, KM_USER1);

	kunmap_atomic(gpu_vaddr, KM_USER0);



	return 0;

	kunmap(cpu_page);

	kunmap(gpu_page);

}



/**
@@ -425,21 +407,19 @@ i915_gem_shmem_pread_slow(struct drm_device *dev, struct drm_gem_object *obj, 
			page_length = PAGE_SIZE - data_page_offset;



		if (do_bit17_swizzling) {

			ret = slow_shmem_bit17_copy(obj_priv->pages[shmem_page_index],

			slow_shmem_bit17_copy(obj_priv->pages[shmem_page_index],

					      shmem_page_offset,

					      user_pages[data_page_index],

					      data_page_offset,

					      page_length,

					      1);

		} else {

			ret = slow_shmem_copy(user_pages[data_page_index],

			slow_shmem_copy(user_pages[data_page_index],

					data_page_offset,

					obj_priv->pages[shmem_page_index],

					shmem_page_offset,

					page_length);

		}

		if (ret)

			goto fail_put_pages;



		remain -= page_length;

		data_ptr += page_length;
@@ -900,21 +880,19 @@ i915_gem_shmem_pwrite_slow(struct drm_device *dev, struct drm_gem_object *obj, 
			page_length = PAGE_SIZE - data_page_offset;



		if (do_bit17_swizzling) {

			ret = slow_shmem_bit17_copy(obj_priv->pages[shmem_page_index],

			slow_shmem_bit17_copy(obj_priv->pages[shmem_page_index],

					      shmem_page_offset,

					      user_pages[data_page_index],

					      data_page_offset,

					      page_length,

					      0);

		} else {

			ret = slow_shmem_copy(obj_priv->pages[shmem_page_index],

			slow_shmem_copy(obj_priv->pages[shmem_page_index],

					shmem_page_offset,

					user_pages[data_page_index],

					data_page_offset,

					page_length);

		}

		if (ret)

			goto fail_put_pages;



		remain -= page_length;

		data_ptr += page_length;