gpu: nvgpu: add support for pre-allocated resources

Add support for pre-allocation of job tracking resources
w/ new (extended) ioctl. Goal is to avoid dynamic memory
allocation in the submit path. This patch does the following:

1) Intoduces a new ioctl, NVGPU_IOCTL_CHANNEL_ALLOC_GPFIFO_EX,
which enables pre-allocation of tracking resources per job:
a) 2x priv_cmd_entry
b) 2x gk20a_fence

2) Implements circular ring buffer for job
tracking to avoid lock contention between producer
(submitter) and consumer (clean-up)

Bug 1795076

Change-Id: I6b52e5c575871107ff380f9a5790f440a6969347
Signed-off-by: Sachit Kadle <skadle@nvidia.com>
Reviewed-on: http://git-master/r/1203300
(cherry picked from commit 9fd270c22b860935dffe244753dabd87454bef39)
Reviewed-on: http://git-master/r/1223934
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>

1 files changed, 13 insertions, 2 deletions

diff --git a/drivers/gpu/nvgpu/gk20a/fence_gk20a.h b/drivers/gpu/nvgpu/gk20a/fence_gk20a.h
index 3fe2d8b2..97a7d957 100644
--- a/drivers/gpu/nvgpu/gk20a/fence_gk20a.h
+++ b/drivers/gpu/nvgpu/gk20a/fence_gk20a.h
@@ -3,7 +3,7 @@
  *
  * GK20A Fences
  *
- * Copyright (c) 2014-2015, NVIDIA CORPORATION.  All rights reserved.
+ * Copyright (c) 2014-2016, NVIDIA CORPORATION.  All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms and conditions of the GNU General Public License,
@@ -45,6 +45,9 @@ struct gk20a_fence {
         struct platform_device *host1x_pdev;
         u32 syncpt_id;
         u32 syncpt_value;
+
+        /* Valid for fences part of a pre-allocated fence pool */
+        struct gk20a_allocator *allocator;
 };
 
 /* Fences can be created from semaphores or syncpoint (id, value) pairs */
@@ -62,7 +65,15 @@ int gk20a_fence_from_syncpt(
                 u32 id, u32 value, bool wfi,
                 bool need_sync_fence);
 
-struct gk20a_fence *gk20a_alloc_fence(struct channel_gk20a *c);
+int gk20a_alloc_fence_pool(
+                struct channel_gk20a *c,
+                int size);
+
+void gk20a_free_fence_pool(
+                struct channel_gk20a *c);
+
+struct gk20a_fence *gk20a_alloc_fence(
+                struct channel_gk20a *c);
 
 void gk20a_init_fence(struct gk20a_fence *f,
                 const struct gk20a_fence_ops *ops,