[RFC PATCH] drm/radeon: fixup locking inversion between mmap_sem and reservations

Maarten Lankhorst maarten.lankhorst at canonical.com
Tue Oct 8 16:14:40 CEST 2013


Allocate and copy all kernel memory before doing reservations. This prevents a locking
inversion between mmap_sem and reservation_class, and allows us to drop the trylocking
in ttm_bo_vm_fault without upsetting lockdep.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst at canonical.com>
---
diff --git a/drivers/gpu/drm/radeon/r600_cs.c b/drivers/gpu/drm/radeon/r600_cs.c
index 01a3ec8..efa9bca 100644
--- a/drivers/gpu/drm/radeon/r600_cs.c
+++ b/drivers/gpu/drm/radeon/r600_cs.c
@@ -2391,18 +2391,13 @@ int r600_cs_legacy(struct drm_device *dev, void *data, struct drm_file *filp,
 	ib_chunk = &parser.chunks[parser.chunk_ib_idx];
 	parser.ib.length_dw = ib_chunk->length_dw;
 	*l = parser.ib.length_dw;
+	memcpy(ib, ib_chunk->kdata, ib_chunk->length_dw * 4);
 	r = r600_cs_parse(&parser);
 	if (r) {
 		DRM_ERROR("Invalid command stream !\n");
 		r600_cs_parser_fini(&parser, r);
 		return r;
 	}
-	r = radeon_cs_finish_pages(&parser);
-	if (r) {
-		DRM_ERROR("Invalid command stream !\n");
-		r600_cs_parser_fini(&parser, r);
-		return r;
-	}
 	r600_cs_parser_fini(&parser, r);
 	return r;
 }
diff --git a/drivers/gpu/drm/radeon/radeon.h b/drivers/gpu/drm/radeon/radeon.h
index e067024..c52bb5e 100644
--- a/drivers/gpu/drm/radeon/radeon.h
+++ b/drivers/gpu/drm/radeon/radeon.h
@@ -983,12 +983,7 @@ struct radeon_cs_reloc {
 struct radeon_cs_chunk {
 	uint32_t		chunk_id;
 	uint32_t		length_dw;
-	int			kpage_idx[2];
-	uint32_t		*kpage[2];
 	uint32_t		*kdata;
-	void __user		*user_ptr;
-	int			last_copied_page;
-	int			last_page_index;
 };
 
 struct radeon_cs_parser {
@@ -1027,8 +1022,13 @@ struct radeon_cs_parser {
 	struct radeon_sa_bo	*cpu_sema;
 };
 
-extern int radeon_cs_finish_pages(struct radeon_cs_parser *p);
-extern u32 radeon_get_ib_value(struct radeon_cs_parser *p, int idx);
+static inline u32 radeon_get_ib_value(struct radeon_cs_parser *p, int idx)
+{
+	struct radeon_cs_chunk *ibc = &p->chunks[p->chunk_ib_idx];
+
+	return ibc->kdata[idx];
+}
+
 
 struct radeon_cs_packet {
 	unsigned	idx;
diff --git a/drivers/gpu/drm/radeon/radeon_cs.c b/drivers/gpu/drm/radeon/radeon_cs.c
index 7d7322e..98d8898 100644
--- a/drivers/gpu/drm/radeon/radeon_cs.c
+++ b/drivers/gpu/drm/radeon/radeon_cs.c
@@ -217,9 +217,7 @@ int radeon_cs_parser_init(struct radeon_cs_parser *p, void *data)
 			return -EFAULT;
 		}
 		p->chunks[i].length_dw = user_chunk.length_dw;
-		p->chunks[i].kdata = NULL;
 		p->chunks[i].chunk_id = user_chunk.chunk_id;
-		p->chunks[i].user_ptr = (void __user *)(unsigned long)user_chunk.chunk_data;
 		if (p->chunks[i].chunk_id == RADEON_CHUNK_ID_RELOCS) {
 			p->chunk_relocs_idx = i;
 		}
@@ -242,25 +240,22 @@ int radeon_cs_parser_init(struct radeon_cs_parser *p, void *data)
 				return -EINVAL;
 		}
 
-		cdata = (uint32_t *)(unsigned long)user_chunk.chunk_data;
-		if ((p->chunks[i].chunk_id == RADEON_CHUNK_ID_RELOCS) ||
-		    (p->chunks[i].chunk_id == RADEON_CHUNK_ID_FLAGS)) {
-			size = p->chunks[i].length_dw * sizeof(uint32_t);
-			p->chunks[i].kdata = kmalloc(size, GFP_KERNEL);
-			if (p->chunks[i].kdata == NULL) {
-				return -ENOMEM;
-			}
-			if (DRM_COPY_FROM_USER(p->chunks[i].kdata,
-					       p->chunks[i].user_ptr, size)) {
-				return -EFAULT;
-			}
-			if (p->chunks[i].chunk_id == RADEON_CHUNK_ID_FLAGS) {
-				p->cs_flags = p->chunks[i].kdata[0];
-				if (p->chunks[i].length_dw > 1)
-					ring = p->chunks[i].kdata[1];
-				if (p->chunks[i].length_dw > 2)
-					priority = (s32)p->chunks[i].kdata[2];
-			}
+		size = p->chunks[i].length_dw;
+		p->chunks[i].kdata = drm_malloc_ab(size, sizeof(uint32_t));
+		size *= sizeof(uint32_t);
+		if (p->chunks[i].kdata == NULL) {
+			return -ENOMEM;
+		}
+		cdata = (void __user *)(unsigned long)user_chunk.chunk_data;
+		if (DRM_COPY_FROM_USER(p->chunks[i].kdata, cdata, size)) {
+			return -EFAULT;
+		}
+		if (p->chunks[i].chunk_id == RADEON_CHUNK_ID_FLAGS) {
+			p->cs_flags = p->chunks[i].kdata[0];
+			if (p->chunks[i].length_dw > 1)
+				ring = p->chunks[i].kdata[1];
+			if (p->chunks[i].length_dw > 2)
+				priority = (s32)p->chunks[i].kdata[2];
 		}
 	}
 
@@ -283,34 +278,6 @@ int radeon_cs_parser_init(struct radeon_cs_parser *p, void *data)
 		}
 	}
 
-	/* deal with non-vm */
-	if ((p->chunk_ib_idx != -1) &&
-	    ((p->cs_flags & RADEON_CS_USE_VM) == 0) &&
-	    (p->chunks[p->chunk_ib_idx].chunk_id == RADEON_CHUNK_ID_IB)) {
-		if (p->chunks[p->chunk_ib_idx].length_dw > (16 * 1024)) {
-			DRM_ERROR("cs IB too big: %d\n",
-				  p->chunks[p->chunk_ib_idx].length_dw);
-			return -EINVAL;
-		}
-		if (p->rdev && (p->rdev->flags & RADEON_IS_AGP)) {
-			p->chunks[p->chunk_ib_idx].kpage[0] = kmalloc(PAGE_SIZE, GFP_KERNEL);
-			p->chunks[p->chunk_ib_idx].kpage[1] = kmalloc(PAGE_SIZE, GFP_KERNEL);
-			if (p->chunks[p->chunk_ib_idx].kpage[0] == NULL ||
-			    p->chunks[p->chunk_ib_idx].kpage[1] == NULL) {
-				kfree(p->chunks[p->chunk_ib_idx].kpage[0]);
-				kfree(p->chunks[p->chunk_ib_idx].kpage[1]);
-				p->chunks[p->chunk_ib_idx].kpage[0] = NULL;
-				p->chunks[p->chunk_ib_idx].kpage[1] = NULL;
-				return -ENOMEM;
-			}
-		}
-		p->chunks[p->chunk_ib_idx].kpage_idx[0] = -1;
-		p->chunks[p->chunk_ib_idx].kpage_idx[1] = -1;
-		p->chunks[p->chunk_ib_idx].last_copied_page = -1;
-		p->chunks[p->chunk_ib_idx].last_page_index =
-			((p->chunks[p->chunk_ib_idx].length_dw * 4) - 1) / PAGE_SIZE;
-	}
-
 	return 0;
 }
 
@@ -450,13 +417,8 @@ static void radeon_cs_parser_fini(struct radeon_cs_parser *parser, int error, bo
 	kfree(parser->track);
 	kfree(parser->relocs);
 	kfree(parser->relocs_ptr);
-	for (i = 0; i < parser->nchunks; i++) {
-		kfree(parser->chunks[i].kdata);
-		if ((parser->rdev->flags & RADEON_IS_AGP)) {
-			kfree(parser->chunks[i].kpage[0]);
-			kfree(parser->chunks[i].kpage[1]);
-		}
-	}
+	for (i = 0; i < parser->nchunks; i++)
+		drm_free_large(parser->chunks[i].kdata);
 	kfree(parser->chunks);
 	kfree(parser->chunks_array);
 	radeon_ib_free(parser->rdev, &parser->ib);
@@ -483,17 +445,15 @@ static int radeon_cs_ib_chunk(struct radeon_device *rdev,
 		DRM_ERROR("Failed to get ib !\n");
 		return r;
 	}
+
+	memcpy(parser->ib.ptr, ib_chunk->kdata, ib_chunk->length_dw * 4);
 	parser->ib.length_dw = ib_chunk->length_dw;
+
 	r = radeon_cs_parse(rdev, parser->ring, parser);
 	if (r || parser->parser_error) {
 		DRM_ERROR("Invalid command stream !\n");
 		return r;
 	}
-	r = radeon_cs_finish_pages(parser);
-	if (r) {
-		DRM_ERROR("Invalid command stream !\n");
-		return r;
-	}
 
 	if (parser->ring == R600_RING_TYPE_UVD_INDEX)
 		radeon_uvd_note_usage(rdev);
@@ -555,10 +515,8 @@ static int radeon_cs_ib_vm_chunk(struct radeon_device *rdev,
 		parser->const_ib.is_const_ib = true;
 		parser->const_ib.length_dw = ib_chunk->length_dw;
 		/* Copy the packet into the IB */
-		if (DRM_COPY_FROM_USER(parser->const_ib.ptr, ib_chunk->user_ptr,
-				       ib_chunk->length_dw * 4)) {
-			return -EFAULT;
-		}
+		memcpy(parser->const_ib.ptr, ib_chunk->kdata,
+		       ib_chunk->length_dw * 4);
 		r = radeon_ring_ib_parse(rdev, parser->ring, &parser->const_ib);
 		if (r) {
 			return r;
@@ -578,10 +536,7 @@ static int radeon_cs_ib_vm_chunk(struct radeon_device *rdev,
 	}
 	parser->ib.length_dw = ib_chunk->length_dw;
 	/* Copy the packet into the IB */
-	if (DRM_COPY_FROM_USER(parser->ib.ptr, ib_chunk->user_ptr,
-			       ib_chunk->length_dw * 4)) {
-		return -EFAULT;
-	}
+	memcpy(parser->ib.ptr, ib_chunk->kdata, ib_chunk->length_dw * 4);
 	r = radeon_ring_ib_parse(rdev, parser->ring, &parser->ib);
 	if (r) {
 		return r;
@@ -704,97 +659,6 @@ int radeon_cs_ioctl(struct drm_device *dev, void *data, struct drm_file *filp)
 	return r;
 }
 
-int radeon_cs_finish_pages(struct radeon_cs_parser *p)
-{
-	struct radeon_cs_chunk *ibc = &p->chunks[p->chunk_ib_idx];
-	int i;
-	int size = PAGE_SIZE;
-
-	for (i = ibc->last_copied_page + 1; i <= ibc->last_page_index; i++) {
-		if (i == ibc->last_page_index) {
-			size = (ibc->length_dw * 4) % PAGE_SIZE;
-			if (size == 0)
-				size = PAGE_SIZE;
-		}
-		
-		if (DRM_COPY_FROM_USER(p->ib.ptr + (i * (PAGE_SIZE/4)),
-				       ibc->user_ptr + (i * PAGE_SIZE),
-				       size))
-			return -EFAULT;
-	}
-	return 0;
-}
-
-static int radeon_cs_update_pages(struct radeon_cs_parser *p, int pg_idx)
-{
-	int new_page;
-	struct radeon_cs_chunk *ibc = &p->chunks[p->chunk_ib_idx];
-	int i;
-	int size = PAGE_SIZE;
-	bool copy1 = (p->rdev && (p->rdev->flags & RADEON_IS_AGP)) ?
-		false : true;
-
-	for (i = ibc->last_copied_page + 1; i < pg_idx; i++) {
-		if (DRM_COPY_FROM_USER(p->ib.ptr + (i * (PAGE_SIZE/4)),
-				       ibc->user_ptr + (i * PAGE_SIZE),
-				       PAGE_SIZE)) {
-			p->parser_error = -EFAULT;
-			return 0;
-		}
-	}
-
-	if (pg_idx == ibc->last_page_index) {
-		size = (ibc->length_dw * 4) % PAGE_SIZE;
-		if (size == 0)
-			size = PAGE_SIZE;
-	}
-
-	new_page = ibc->kpage_idx[0] < ibc->kpage_idx[1] ? 0 : 1;
-	if (copy1)
-		ibc->kpage[new_page] = p->ib.ptr + (pg_idx * (PAGE_SIZE / 4));
-
-	if (DRM_COPY_FROM_USER(ibc->kpage[new_page],
-			       ibc->user_ptr + (pg_idx * PAGE_SIZE),
-			       size)) {
-		p->parser_error = -EFAULT;
-		return 0;
-	}
-
-	/* copy to IB for non single case */
-	if (!copy1)
-		memcpy((void *)(p->ib.ptr+(pg_idx*(PAGE_SIZE/4))), ibc->kpage[new_page], size);
-
-	ibc->last_copied_page = pg_idx;
-	ibc->kpage_idx[new_page] = pg_idx;
-
-	return new_page;
-}
-
-u32 radeon_get_ib_value(struct radeon_cs_parser *p, int idx)
-{
-	struct radeon_cs_chunk *ibc = &p->chunks[p->chunk_ib_idx];
-	u32 pg_idx, pg_offset;
-	u32 idx_value = 0;
-	int new_page;
-
-	pg_idx = (idx * 4) / PAGE_SIZE;
-	pg_offset = (idx * 4) % PAGE_SIZE;
-
-	if (ibc->kpage_idx[0] == pg_idx)
-		return ibc->kpage[0][pg_offset/4];
-	if (ibc->kpage_idx[1] == pg_idx)
-		return ibc->kpage[1][pg_offset/4];
-
-	new_page = radeon_cs_update_pages(p, pg_idx);
-	if (new_page < 0) {
-		p->parser_error = new_page;
-		return 0;
-	}
-
-	idx_value = ibc->kpage[new_page][pg_offset/4];
-	return idx_value;
-}
-
 /**
  * radeon_cs_packet_parse() - parse cp packet and point ib index to next packet
  * @parser:	parser structure holding parsing context.



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