If the GEM objects being rendered with in this request have been
exported via dma-buf to a third party, hook ourselves into the dma-buf
reservation object so that the third party can serialise with our
rendering via the dma-buf fences.
Testcase: igt/prime_busy
Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/i915/i915_gem_dmabuf.c | 42 +++++++++++++++++++++++++++---
drivers/gpu/drm/i915/i915_gem_execbuffer.c | 30 +++++++++++++++++++--
2 files changed, 67 insertions(+), 5 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_gem_dmabuf.c b/drivers/gpu/drm/i915/i915_gem_dmabuf.c
index 80bbe43a2e92..075d7a94e77c 100644
--- a/drivers/gpu/drm/i915/i915_gem_dmabuf.c
+++ b/drivers/gpu/drm/i915/i915_gem_dmabuf.c
@@ -23,9 +23,13 @@
* Authors:
* Dave Airlie <airlied@xxxxxxxxxx>
*/
+
+#include <linux/dma-buf.h>
+#include <linux/reservation.h>
+
#include <drm/drmP.h>
+
#include "i915_drv.h"
-#include <linux/dma-buf.h>
static struct drm_i915_gem_object *dma_buf_to_obj(struct dma_buf *buf)
{
@@ -218,25 +222,57 @@ static const struct dma_buf_ops i915_dmabuf_ops = {
.end_cpu_access = i915_gem_end_cpu_access,
};
+static void export_fences(struct drm_i915_gem_object *obj,
+ struct dma_buf *dma_buf)
+{
+ struct reservation_object *resv = dma_buf->resv;
+ struct drm_i915_gem_request *req;
+ int idx;
+
+ mutex_lock(&obj->base.dev->struct_mutex);
+ mutex_lock(&resv->lock.base);
+
+ for (idx = 0; idx < ARRAY_SIZE(obj->last_read_req); idx++) {
+ req = obj->last_read_req[idx];
+ if (!req)
+ continue;
+
+ if (reservation_object_reserve_shared(resv) == 0)
+ reservation_object_add_shared_fence(resv, &req->fence);
+ }
+
+ req = obj->last_write_req;
+ if (req)
+ reservation_object_add_excl_fence(resv, &req->fence);
+
+ mutex_unlock(&resv->lock.base);
+ mutex_unlock(&obj->base.dev->struct_mutex);
+}
+
struct dma_buf *i915_gem_prime_export(struct drm_device *dev,
struct drm_gem_object *gem_obj, int flags)
{
struct drm_i915_gem_object *obj = to_intel_bo(gem_obj);
DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
+ struct dma_buf *dma_buf;
exp_info.ops = &i915_dmabuf_ops;
exp_info.size = gem_obj->size;
exp_info.flags = flags;
exp_info.priv = gem_obj;
-
if (obj->ops->dmabuf_export) {
int ret = obj->ops->dmabuf_export(obj);
if (ret)
return ERR_PTR(ret);
}
- return dma_buf_export(&exp_info);
+ dma_buf = dma_buf_export(&exp_info);
+ if (IS_ERR(dma_buf))
+ return dma_buf;
+
+ export_fences(obj, dma_buf);
+ return dma_buf;
}
static int i915_gem_object_get_pages_dmabuf(struct drm_i915_gem_object *obj)
diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
index 1978633e7549..359ef0afa312 100644
--- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
@@ -26,13 +26,17 @@
*
*/
+#include <linux/dma_remapping.h>
+#include <linux/reservation.h>
+#include <linux/uaccess.h>
+
#include <drm/drmP.h>
#include <drm/i915_drm.h>
+
#include "i915_drv.h"
+#include "i915_gem_dmabuf.h"
#include "i915_trace.h"
#include "intel_drv.h"
-#include <linux/dma_remapping.h>
-#include <linux/uaccess.h>
#define __EXEC_OBJECT_HAS_PIN (1<<31)
#define __EXEC_OBJECT_HAS_FENCE (1<<30)
@@ -1086,6 +1090,27 @@ i915_gem_validate_context(struct drm_device *dev, struct drm_file *file,
return ctx;
}
+static void eb_export_fence(struct drm_i915_gem_object *obj,
+ struct drm_i915_gem_request *req)
+{
+ struct reservation_object *resv;
+
+ resv = i915_gem_object_get_dmabuf_resv(obj);
+ if (!resv)
+ return;
+
+ /* Ignore errors from failing to allocate the new fence, we can't
+ * handle an error right now. Worst case should be missed
+ * synchronisation leading to rendering corruption.
+ */
+ mutex_lock(&resv->lock.base);
+ if (obj->base.write_domain)
+ reservation_object_add_excl_fence(resv, &req->fence);
+ else if (reservation_object_reserve_shared(resv) == 0)
+ reservation_object_add_shared_fence(resv, &req->fence);
+ mutex_unlock(&resv->lock.base);
+}
+
void
i915_gem_execbuffer_move_to_active(struct list_head *vmas,
struct drm_i915_gem_request *req)
@@ -1106,6 +1131,7 @@ i915_gem_execbuffer_move_to_active(struct list_head *vmas,
obj->base.read_domains = obj->base.pending_read_domains;
i915_vma_move_to_active(vma, req);
+ eb_export_fence(obj, req);
if (obj->base.write_domain) {
i915_gem_request_assign(&obj->last_write_req, req);
--
2.8.1
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