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Commit 4c9613ce authored by Chris Wilson's avatar Chris Wilson Committed by Rodrigo Vivi
Browse files

drm/i915: Handle incomplete Z_FINISH for compressed error states 



The final call to zlib_deflate(Z_FINISH) may require more output
space to be allocated and so needs to re-invoked. Failure to do so in
the current code leads to incomplete zlib streams (albeit intact due to
the use of Z_SYNC_FLUSH) resulting in the occasional short object
capture.

v2: Check against overrunning our pre-allocated page array
v3: Drop Z_SYNC_FLUSH entirely

Testcase: igt/i915-error-capture.js
Fixes: 0a97015d ("drm/i915: Compress GPU objects in error state")
Signed-off-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: <stable@vger.kernel.org> # v4.10+
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: default avatarTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181003082422.23214-1-chris@chris-wilson.co.uk


(cherry picked from commit 83bc0f5b432f60394466deef16fc753e27371d0b)
Signed-off-by: default avatarRodrigo Vivi <rodrigo.vivi@intel.com>
parent 4ca8ca9f

drivers/gpu/drm/i915/i915_gpu_error.c

+63 −25
Original line number Diff line number Diff line
@@ -232,6 +232,20 @@ static bool compress_init(struct compress *c) 
	return true;

}



static void *compress_next_page(struct drm_i915_error_object *dst)

{

	unsigned long page;



	if (dst->page_count >= dst->num_pages)

		return ERR_PTR(-ENOSPC);



	page = __get_free_page(GFP_ATOMIC | __GFP_NOWARN);

	if (!page)

		return ERR_PTR(-ENOMEM);



	return dst->pages[dst->page_count++] = (void *)page;

}



static int compress_page(struct compress *c,

			 void *src,

			 struct drm_i915_error_object *dst)
@@ -245,19 +259,14 @@ static int compress_page(struct compress *c, 


	do {

		if (zstream->avail_out == 0) {

			unsigned long page;

			zstream->next_out = compress_next_page(dst);

			if (IS_ERR(zstream->next_out))

				return PTR_ERR(zstream->next_out);



			page = __get_free_page(GFP_ATOMIC | __GFP_NOWARN);

			if (!page)

				return -ENOMEM;



			dst->pages[dst->page_count++] = (void *)page;



			zstream->next_out = (void *)page;

			zstream->avail_out = PAGE_SIZE;

		}



		if (zlib_deflate(zstream, Z_SYNC_FLUSH) != Z_OK)

		if (zlib_deflate(zstream, Z_NO_FLUSH) != Z_OK)

			return -EIO;

	} while (zstream->avail_in);
@@ -268,19 +277,42 @@ static int compress_page(struct compress *c, 
	return 0;

}



static void compress_fini(struct compress *c,

static int compress_flush(struct compress *c,

			  struct drm_i915_error_object *dst)

{

	struct z_stream_s *zstream = &c->zstream;



	if (dst) {

		zlib_deflate(zstream, Z_FINISH);

	do {

		switch (zlib_deflate(zstream, Z_FINISH)) {

		case Z_OK: /* more space requested */

			zstream->next_out = compress_next_page(dst);

			if (IS_ERR(zstream->next_out))

				return PTR_ERR(zstream->next_out);



			zstream->avail_out = PAGE_SIZE;

			break;



		case Z_STREAM_END:

			goto end;



		default: /* any error */

			return -EIO;

		}

	} while (1);



end:

	memset(zstream->next_out, 0, zstream->avail_out);

	dst->unused = zstream->avail_out;

	return 0;

}



static void compress_fini(struct compress *c,

			  struct drm_i915_error_object *dst)

{

	struct z_stream_s *zstream = &c->zstream;



	zlib_deflateEnd(zstream);

	kfree(zstream->workspace);



	if (c->tmp)

		free_page((unsigned long)c->tmp);

}
@@ -319,6 +351,12 @@ static int compress_page(struct compress *c, 
	return 0;

}



static int compress_flush(struct compress *c,

			  struct drm_i915_error_object *dst)

{

	return 0;

}



static void compress_fini(struct compress *c,

			  struct drm_i915_error_object *dst)

{
@@ -917,6 +955,7 @@ i915_error_object_create(struct drm_i915_private *i915, 
	unsigned long num_pages;

	struct sgt_iter iter;

	dma_addr_t dma;

	int ret;



	if (!vma)

		return NULL;
@@ -930,6 +969,7 @@ i915_error_object_create(struct drm_i915_private *i915, 


	dst->gtt_offset = vma->node.start;

	dst->gtt_size = vma->node.size;

	dst->num_pages = num_pages;

	dst->page_count = 0;

	dst->unused = 0;
@@ -938,28 +978,26 @@ i915_error_object_create(struct drm_i915_private *i915, 
		return NULL;

	}



	ret = -EINVAL;

	for_each_sgt_dma(dma, iter, vma->pages) {

		void __iomem *s;

		int ret;



		ggtt->vm.insert_page(&ggtt->vm, dma, slot, I915_CACHE_NONE, 0);



		s = io_mapping_map_atomic_wc(&ggtt->iomap, slot);

		ret = compress_page(&compress, (void  __force *)s, dst);

		io_mapping_unmap_atomic(s);



		if (ret)

			goto unwind;

			break;

	}

	goto out;



unwind:

	if (ret || compress_flush(&compress, dst)) {

		while (dst->page_count--)

			free_page((unsigned long)dst->pages[dst->page_count]);

		kfree(dst);

		dst = NULL;

	}



out:

	compress_fini(&compress, dst);

	ggtt->vm.clear_range(&ggtt->vm, slot, PAGE_SIZE);

	return dst;

drivers/gpu/drm/i915/i915_gpu_error.h

+1 −0
Original line number Diff line number Diff line
@@ -135,6 +135,7 @@ struct i915_gpu_state { 
		struct drm_i915_error_object {

			u64 gtt_offset;

			u64 gtt_size;

			int num_pages;

			int page_count;

			int unused;

			u32 *pages[0];