[PATCH 4/5] drm/i915/dmabuf: Add LMEM support for cpu access and vmap interfaces

[Michael J. Ruhl]

LMEM backed buffer objects do not have struct page information, and
are not WB compatible.  Currently the cpu access and vmap interfaces
only support struct page backed objects.

Update the dma-buf interfaces begin/end_cpu_access and vmap/vunmap
to be LMEM aware.

Signed-off-by: Michael J. Ruhl <michael.j.ruhl at intel.com>
---
 drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c b/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c
index 402c989cc23d..988778cc8539 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c
@@ -155,7 +155,10 @@ static void *i915_gem_dmabuf_vmap(struct dma_buf *dma_buf)
 {
 	struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);
 
-	return i915_gem_object_pin_map(obj, I915_MAP_WB);
+	if (i915_gem_object_has_struct_page(obj))
+		return i915_gem_object_pin_map(obj, I915_MAP_WB);
+	else
+		return i915_gem_object_pin_map(obj, I915_MAP_WC);
 }
 
 static void i915_gem_dmabuf_vunmap(struct dma_buf *dma_buf, void *vaddr)
@@ -201,7 +204,11 @@ static int i915_gem_begin_cpu_access(struct dma_buf *dma_buf, enum dma_data_dire
 	if (err)
 		goto out;
 
-	err = i915_gem_object_set_to_cpu_domain(obj, write);
+	if (i915_gem_object_has_struct_page(obj))
+		err = i915_gem_object_set_to_cpu_domain(obj, write);
+	else
+		err = i915_gem_object_set_to_wc_domain(obj, write);
+
 	i915_gem_object_unlock(obj);
 
 out:
@@ -222,7 +229,9 @@ static int i915_gem_end_cpu_access(struct dma_buf *dma_buf, enum dma_data_direct
 	if (err)
 		goto out;
 
-	err = i915_gem_object_set_to_gtt_domain(obj, false);
+	if (i915_gem_object_has_struct_page(obj))
+		err = i915_gem_object_set_to_gtt_domain(obj, false);
+
 	i915_gem_object_unlock(obj);
 
 out:
-- 
2.21.0