Mesa (master): iris: Fix resource tracking for CS thread ID buffer

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Module: Mesa
Branch: master
Commit: 340df53d6a9dea21a968bb040232ffa66db53add
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=340df53d6a9dea21a968bb040232ffa66db53add

Author: Kenneth Graunke <kenneth at whitecape.org>
Date:   Wed Jun 26 23:38:59 2019 -0700

iris: Fix resource tracking for CS thread ID buffer

Today, we stream the compute shader thread IDs simply because they're
(annoyingly) relative to dynamic state base address.  We could upload
them once at compile time, but we'd need a separate non-streaming
uploader for IRIS_MEMZONE_DYNAMIC, and I'm not sure it's worth it.

stream_state pins the buffer for use in the current batch, but also
returns a reference to the pipe_resource.  We dropped this reference
on the floor, leaking a reference basically every time we dispatched
a compute shader after switching to a new one.

The reason it returns a reference is so that we can hold on to it and
re-pin it in iris_restore_compute_saved_bos, which we were also failing
to do.  So if we actually filled up a batch with repeated dispatches to
the same compute shader, and flushed, then continued dispatching, we
would fail to pin it and likely GPU hang.

---

 src/gallium/drivers/iris/iris_context.h | 1 +
 src/gallium/drivers/iris/iris_state.c   | 9 +++++++--
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/src/gallium/drivers/iris/iris_context.h b/src/gallium/drivers/iris/iris_context.h
index e34ea930eae..21877173b3f 100644
--- a/src/gallium/drivers/iris/iris_context.h
+++ b/src/gallium/drivers/iris/iris_context.h
@@ -712,6 +712,7 @@ struct iris_context {
          struct pipe_resource *scissor;
          struct pipe_resource *blend;
          struct pipe_resource *index_buffer;
+         struct pipe_resource *cs_thread_ids;
       } last_res;
 
       /** Records the size of variable-length state for INTEL_DEBUG=bat */
diff --git a/src/gallium/drivers/iris/iris_state.c b/src/gallium/drivers/iris/iris_state.c
index 385d99bdb4f..5de994893e0 100644
--- a/src/gallium/drivers/iris/iris_state.c
+++ b/src/gallium/drivers/iris/iris_state.c
@@ -4369,6 +4369,10 @@ iris_restore_compute_saved_bos(struct iris_context *ice,
          struct iris_bo *bo = iris_resource_bo(shader->assembly.res);
          iris_use_pinned_bo(batch, bo, false);
 
+         struct iris_bo *curbe_bo =
+            iris_resource_bo(ice->state.last_res.cs_thread_ids);
+         iris_use_pinned_bo(batch, curbe_bo, false);
+
          struct brw_stage_prog_data *prog_data = shader->prog_data;
 
          if (prog_data->total_scratch > 0) {
@@ -5507,9 +5511,9 @@ iris_upload_compute_state(struct iris_context *ice,
       assert(cs_prog_data->push.cross_thread.dwords == 0 &&
              cs_prog_data->push.per_thread.dwords == 1 &&
              cs_prog_data->base.param[0] == BRW_PARAM_BUILTIN_SUBGROUP_ID);
-      struct pipe_resource *curbe_data_res = NULL;
       uint32_t *curbe_data_map =
-         stream_state(batch, ice->state.dynamic_uploader, &curbe_data_res,
+         stream_state(batch, ice->state.dynamic_uploader,
+                      &ice->state.last_res.cs_thread_ids,
                       ALIGN(cs_prog_data->push.total.size, 64), 64,
                       &curbe_data_offset);
       assert(curbe_data_map);
@@ -5653,6 +5657,7 @@ iris_destroy_state(struct iris_context *ice)
    pipe_resource_reference(&ice->state.last_res.scissor, NULL);
    pipe_resource_reference(&ice->state.last_res.blend, NULL);
    pipe_resource_reference(&ice->state.last_res.index_buffer, NULL);
+   pipe_resource_reference(&ice->state.last_res.cs_thread_ids, NULL);
 }
 
 /* ------------------------------------------------------------------- */