gpu: nvgpu: create sync_fence only if needed

Currently, we create sync_fence (from nvhost_sync_create_fence())
for every submit
But not all submits request for a sync_fence.

Also, nvhost_sync_create_fence() API takes about 1/3rd of the total
submit path.

Hence to optimize, we can allocate sync_fence
only when user explicitly asks for it using
(NVGPU_SUBMIT_GPFIFO_FLAGS_FENCE_GET &&
NVGPU_SUBMIT_GPFIFO_FLAGS_SYNC_FENCE)

Also, in CDE path from gk20a_prepare_compressible_read(),
we reuse existing fence stored in "state" and that can
result into not returning sync_fence_fd when user asked
for it
Hence, force allocation of sync_fence when job submission
comes from CDE path

Bug 200141116

Change-Id: Ia921701bf0e2432d6b8a5e8b7d91160e7f52db1e
Signed-off-by: Deepak Nibade <dnibade@nvidia.com>
Reviewed-on: http://git-master/r/812845
(cherry picked from commit 5fd47015eeed00352cc8473eff969a66c94fee98)
Reviewed-on: http://git-master/r/837662
Reviewed-by: Automatic_Commit_Validation_User
GVS: Gerrit_Virtual_Submit
Reviewed-by: Sachin Nikam <snikam@nvidia.com>

7 files changed, 54 insertions, 29 deletions

diff --git a/drivers/gpu/nvgpu/gk20a/cde_gk20a.c b/drivers/gpu/nvgpu/gk20a/cde_gk20a.c
index e1edec2a..a2f7e7a4 100644
--- a/drivers/gpu/nvgpu/gk20a/cde_gk20a.c
+++ b/drivers/gpu/nvgpu/gk20a/cde_gk20a.c
@@ -724,7 +724,7 @@ static int gk20a_cde_execute_buffer(struct gk20a_cde_ctx *cde_ctx,
         }
 
         return gk20a_submit_channel_gpfifo(cde_ctx->ch, gpfifo, NULL,
-                                           num_entries, flags, fence, fence_out);
+                                   num_entries, flags, fence, fence_out, true);
 }
 
 static void gk20a_cde_ctx_release(struct gk20a_cde_ctx *cde_ctx)
diff --git a/drivers/gpu/nvgpu/gk20a/channel_gk20a.c b/drivers/gpu/nvgpu/gk20a/channel_gk20a.c
index 59c3e31d..98c8760e 100644
--- a/drivers/gpu/nvgpu/gk20a/channel_gk20a.c
+++ b/drivers/gpu/nvgpu/gk20a/channel_gk20a.c
@@ -1830,7 +1830,8 @@ int gk20a_submit_channel_gpfifo(struct channel_gk20a *c,
                                 u32 num_entries,
                                 u32 flags,
                                 struct nvgpu_fence *fence,
-                                struct gk20a_fence **fence_out)
+                                struct gk20a_fence **fence_out,
+                                bool force_need_sync_fence)
 {
         struct gk20a *g = c->g;
         struct device *d = dev_from_gk20a(g);
@@ -1848,6 +1849,14 @@ int gk20a_submit_channel_gpfifo(struct channel_gk20a *c,
         struct nvgpu_gpfifo *gpfifo_mem = c->gpfifo.mem.cpu_va;
         bool skip_buffer_refcounting = (flags &
                         NVGPU_SUBMIT_GPFIFO_FLAGS_SKIP_BUFFER_REFCOUNTING);
+        bool need_sync_fence = false;
+
+        /*
+         * If user wants to allocate sync_fence_fd always, then respect that;
+         * otherwise, allocate sync_fence_fd based on user flags only
+         */
+        if (force_need_sync_fence)
+                need_sync_fence = true;
 
         if (c->has_timedout)
                 return -ETIMEDOUT;
@@ -1970,15 +1979,18 @@ int gk20a_submit_channel_gpfifo(struct channel_gk20a *c,
                 goto clean_up;
         }
 
+        if ((flags & NVGPU_SUBMIT_GPFIFO_FLAGS_FENCE_GET) &&
+                        (flags & NVGPU_SUBMIT_GPFIFO_FLAGS_SYNC_FENCE))
+                need_sync_fence = true;
 
         /* always insert syncpt increment at end of gpfifo submission
            to keep track of method completion for idle railgating */
         if (flags & NVGPU_SUBMIT_GPFIFO_FLAGS_FENCE_GET)
                 err = c->sync->incr_user(c->sync, wait_fence_fd, &incr_cmd,
-                                         &post_fence, need_wfi);
+                                 &post_fence, need_wfi, need_sync_fence);
         else
                 err = c->sync->incr(c->sync, &incr_cmd,
-                                    &post_fence);
+                                    &post_fence, need_sync_fence);
         if (err) {
                 mutex_unlock(&c->submit_lock);
                 goto clean_up;
@@ -2578,7 +2590,7 @@ static int gk20a_ioctl_channel_submit_gpfifo(
 
         ret = gk20a_submit_channel_gpfifo(ch, NULL, args, args->num_entries,
                                           args->flags, &args->fence,
-                                          &fence_out);
+                                          &fence_out, false);
 
         if (ret)
                 goto clean_up;
diff --git a/drivers/gpu/nvgpu/gk20a/channel_gk20a.h b/drivers/gpu/nvgpu/gk20a/channel_gk20a.h
index 55528dd9..d3428788 100644
--- a/drivers/gpu/nvgpu/gk20a/channel_gk20a.h
+++ b/drivers/gpu/nvgpu/gk20a/channel_gk20a.h
@@ -244,7 +244,8 @@ int gk20a_submit_channel_gpfifo(struct channel_gk20a *c,
                                 u32 num_entries,
                                 u32 flags,
                                 struct nvgpu_fence *fence,
-                                struct gk20a_fence **fence_out);
+                                struct gk20a_fence **fence_out,
+                                bool force_need_sync_fence);
 
 int gk20a_alloc_channel_gpfifo(struct channel_gk20a *c,
                                struct nvgpu_alloc_gpfifo_args *args);
diff --git a/drivers/gpu/nvgpu/gk20a/channel_sync_gk20a.c b/drivers/gpu/nvgpu/gk20a/channel_sync_gk20a.c
index 95647774..c0c8ec6d 100644
--- a/drivers/gpu/nvgpu/gk20a/channel_sync_gk20a.c
+++ b/drivers/gpu/nvgpu/gk20a/channel_sync_gk20a.c
@@ -166,7 +166,8 @@ static int __gk20a_channel_syncpt_incr(struct gk20a_channel_sync *s,
                                        bool wfi_cmd,
                                        bool register_irq,
                                        struct priv_cmd_entry **entry,
-                                       struct gk20a_fence **fence)
+                                       struct gk20a_fence **fence,
+                                       bool need_sync_fence)
 {
         u32 thresh;
         int incr_cmd_size;
@@ -239,7 +240,7 @@ static int __gk20a_channel_syncpt_incr(struct gk20a_channel_sync *s,
         }
 
         *fence = gk20a_fence_from_syncpt(sp->host1x_pdev, sp->id, thresh,
-                                         wfi_cmd);
+                                         wfi_cmd, need_sync_fence);
         *entry = incr_cmd;
         return 0;
 }
@@ -251,33 +252,35 @@ static int gk20a_channel_syncpt_incr_wfi(struct gk20a_channel_sync *s,
         return __gk20a_channel_syncpt_incr(s,
                         true /* wfi */,
                         false /* no irq handler */,
-                        entry, fence);
+                        entry, fence, true);
 }
 
 static int gk20a_channel_syncpt_incr(struct gk20a_channel_sync *s,
                               struct priv_cmd_entry **entry,
-                              struct gk20a_fence **fence)
+                              struct gk20a_fence **fence,
+                              bool need_sync_fence)
 {
         /* Don't put wfi cmd to this one since we're not returning
          * a fence to user space. */
         return __gk20a_channel_syncpt_incr(s,
                         false /* no wfi */,
                         true /* register irq */,
-                        entry, fence);
+                        entry, fence, need_sync_fence);
 }
 
 static int gk20a_channel_syncpt_incr_user(struct gk20a_channel_sync *s,
                                    int wait_fence_fd,
                                    struct priv_cmd_entry **entry,
                                    struct gk20a_fence **fence,
-                                   bool wfi)
+                                   bool wfi,
+                                   bool need_sync_fence)
 {
         /* Need to do 'wfi + host incr' since we return the fence
          * to user space. */
         return __gk20a_channel_syncpt_incr(s,
                         wfi,
                         true /* register irq */,
-                        entry, fence);
+                        entry, fence, need_sync_fence);
 }
 
 static void gk20a_channel_syncpt_set_min_eq_max(struct gk20a_channel_sync *s)
@@ -513,7 +516,8 @@ static int __gk20a_channel_semaphore_incr(
                 struct gk20a_channel_sync *s, bool wfi_cmd,
                 struct sync_fence *dependency,
                 struct priv_cmd_entry **entry,
-                struct gk20a_fence **fence)
+                struct gk20a_fence **fence,
+                bool need_sync_fence)
 {
         u64 va;
         int incr_cmd_size;
@@ -560,18 +564,19 @@ static int gk20a_channel_semaphore_incr_wfi(
         return __gk20a_channel_semaphore_incr(s,
                         true /* wfi */,
                         NULL,
-                        entry, fence);
+                        entry, fence, true);
 }
 
 static int gk20a_channel_semaphore_incr(
                 struct gk20a_channel_sync *s,
                 struct priv_cmd_entry **entry,
-                struct gk20a_fence **fence)
+                struct gk20a_fence **fence,
+                bool need_sync_fence)
 {
         /* Don't put wfi cmd to this one since we're not returning
          * a fence to user space. */
         return __gk20a_channel_semaphore_incr(s, false /* no wfi */,
-                                              NULL, entry, fence);
+                                      NULL, entry, fence, need_sync_fence);
 }
 
 static int gk20a_channel_semaphore_incr_user(
@@ -579,7 +584,8 @@ static int gk20a_channel_semaphore_incr_user(
                 int wait_fence_fd,
                 struct priv_cmd_entry **entry,
                 struct gk20a_fence **fence,
-                bool wfi)
+                bool wfi,
+                bool need_sync_fence)
 {
 #ifdef CONFIG_SYNC
         struct sync_fence *dependency = NULL;
@@ -592,7 +598,7 @@ static int gk20a_channel_semaphore_incr_user(
         }
 
         err = __gk20a_channel_semaphore_incr(s, wfi, dependency,
-                                             entry, fence);
+                                             entry, fence, need_sync_fence);
         if (err) {
                 if (dependency)
                         sync_fence_put(dependency);
diff --git a/drivers/gpu/nvgpu/gk20a/channel_sync_gk20a.h b/drivers/gpu/nvgpu/gk20a/channel_sync_gk20a.h
index a347cbab..618e1b26 100644
--- a/drivers/gpu/nvgpu/gk20a/channel_sync_gk20a.h
+++ b/drivers/gpu/nvgpu/gk20a/channel_sync_gk20a.h
@@ -3,7 +3,7 @@
  *
  * GK20A Channel Synchronization Abstraction
  *
- * Copyright (c) 2014, NVIDIA CORPORATION.  All rights reserved.
+ * Copyright (c) 2014-2015, 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,
@@ -54,7 +54,8 @@ struct gk20a_channel_sync {
          */
         int (*incr)(struct gk20a_channel_sync *s,
                     struct priv_cmd_entry **entry,
-                    struct gk20a_fence **fence);
+                    struct gk20a_fence **fence,
+                    bool need_sync_fence);
 
         /* Increment syncpoint/semaphore, preceded by a wfi.
          * Returns
@@ -76,7 +77,8 @@ struct gk20a_channel_sync {
                          int wait_fence_fd,
                          struct priv_cmd_entry **entry,
                          struct gk20a_fence **fence,
-                         bool wfi);
+                         bool wfi,
+                         bool need_sync_fence);
 
         /* Reset the channel syncpoint/semaphore. */
         void (*set_min_eq_max)(struct gk20a_channel_sync *s);
diff --git a/drivers/gpu/nvgpu/gk20a/fence_gk20a.c b/drivers/gpu/nvgpu/gk20a/fence_gk20a.c
index 54a288cd..ae19d36f 100644
--- a/drivers/gpu/nvgpu/gk20a/fence_gk20a.c
+++ b/drivers/gpu/nvgpu/gk20a/fence_gk20a.c
@@ -194,7 +194,8 @@ static const struct gk20a_fence_ops gk20a_syncpt_fence_ops = {
 };
 
 struct gk20a_fence *gk20a_fence_from_syncpt(struct platform_device *host1x_pdev,
-                                            u32 id, u32 value, bool wfi)
+                                            u32 id, u32 value, bool wfi,
+                                            bool need_sync_fence)
 {
         struct gk20a_fence *f;
         struct sync_fence *sync_fence = NULL;
@@ -205,10 +206,12 @@ struct gk20a_fence *gk20a_fence_from_syncpt(struct platform_device *host1x_pdev,
                 .thresh = value
         };
 
-        sync_fence = nvhost_sync_create_fence(host1x_pdev, &pt, 1,
-                                              "fence");
-        if (IS_ERR(sync_fence))
-                return NULL;
+        if (need_sync_fence) {
+                sync_fence = nvhost_sync_create_fence(host1x_pdev, &pt, 1,
+                                                      "fence");
+                if (IS_ERR(sync_fence))
+                        return NULL;
+        }
 #endif
 
         f = alloc_fence(&gk20a_syncpt_fence_ops, sync_fence, wfi);
diff --git a/drivers/gpu/nvgpu/gk20a/fence_gk20a.h b/drivers/gpu/nvgpu/gk20a/fence_gk20a.h
index 629dc694..75e135e9 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, NVIDIA CORPORATION.  All rights reserved.
+ * Copyright (c) 2014-2015, 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,
@@ -56,7 +56,8 @@ struct gk20a_fence *gk20a_fence_from_semaphore(
 
 struct gk20a_fence *gk20a_fence_from_syncpt(
                 struct platform_device *host1x_pdev,
-                u32 id, u32 value, bool wfi);
+                u32 id, u32 value, bool wfi,
+                bool need_sync_fence);
 
 /* Fence operations */
 void gk20a_fence_put(struct gk20a_fence *f);