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 | 56 ++++++++++++++++++++++++++++--
drivers/gpu/drm/i915/i915_gem_execbuffer.c | 33 ++++++++++++++++--
2 files changed, 83 insertions(+), 6 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_gem_dmabuf.c b/drivers/gpu/drm/i915/i915_gem_dmabuf.c
index 3a00ab3ad06e..bab71ba9c25a 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 +222,71 @@ 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;
+ unsigned long active;
+ int idx;
+
+ active = __I915_BO_ACTIVE(obj);
+ if (!active)
+ return;
+
+ /* Mark the object for future fences before racily adding old fences */
+ obj->base.dma_buf = dma_buf;
+
+ mutex_lock(&resv->lock.base);
+
+ for_each_active(active, idx) {
+ rcu_read_lock();
+ req = i915_gem_active_get_rcu(&obj->last_read[idx]);
+ rcu_read_unlock();
+ if (!req)
+ continue;
+
+ if (reservation_object_reserve_shared(resv) == 0)
+ reservation_object_add_shared_fence(resv, &req->fence);
+
+ i915_gem_request_put(req);
+ }
+
+ rcu_read_lock();
+ req = i915_gem_active_get_rcu(&obj->last_write);
+ rcu_read_unlock();
+ if (req) {
+ reservation_object_add_excl_fence(resv, &req->fence);
+ i915_gem_request_put(req);
+ }
+
+ mutex_unlock(&resv->lock.base);
+}
+
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 0d28703d991a..e2aba40bf328 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)
@@ -1193,7 +1197,29 @@ void i915_vma_move_to_active(struct i915_vma *vma,
list_move_tail(&vma->vm_link, &vma->vm->active_list);
}
-static void
+static void eb_export_fence(struct drm_i915_gem_object *obj,
+ struct drm_i915_gem_request *req,
+ unsigned int flags)
+{
+ 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 (flags & EXEC_OBJECT_WRITE)
+ 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)
{
@@ -1212,6 +1238,7 @@ 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, vma->exec_entry->flags);
+ eb_export_fence(obj, req, vma->exec_entry->flags);
trace_i915_gem_object_change_domain(obj, old_read, old_write);
}
}
--
2.8.1
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