gpu: nvgpu: allocate ctxsw buffers once only

In *_set_ctxsw_preemption_mode, only allocate
buffers the first time through.

Bug 200418468

Change-Id: I22d06463416615b9a9d671c32b6fe76b602a2623
Signed-off-by: Peter Daifuku <pdaifuku@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/2004301
Reviewed-by: Automatic_Commit_Validation_User
GVS: Gerrit_Virtual_Submit
Reviewed-by: Alex Waterman <alexw@nvidia.com>
Reviewed-by: Satish Arora <satisha@nvidia.com>
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>

1 files changed, 23 insertions, 20 deletions

diff --git a/drivers/gpu/nvgpu/gp10b/gr_gp10b.c b/drivers/gpu/nvgpu/gp10b/gr_gp10b.c
index be1e2038..f70a5a00 100644
--- a/drivers/gpu/nvgpu/gp10b/gr_gp10b.c
+++ b/drivers/gpu/nvgpu/gp10b/gr_gp10b.c
@@ -1,7 +1,7 @@
 /*
  * GP10B GPU GR
  *
- * Copyright (c) 2015-2018, NVIDIA CORPORATION.  All rights reserved.
+ * Copyright (c) 2015-2019, NVIDIA CORPORATION.  All rights reserved.
  *
  * Permission is hereby granted, free of charge, to any person obtaining a
  * copy of this software and associated documentation files (the "Software"),
@@ -1013,36 +1013,39 @@ int gr_gp10b_set_ctxsw_preemption_mode(struct gk20a *g,
                 nvgpu_log_info(g, "gfxp context attrib_cb_size=%d",
                                 attrib_cb_size);
 
-                err = gr_gp10b_alloc_buffer(vm,
+                /* Only allocate buffers the first time through */
+                if (!nvgpu_mem_is_valid(&gr_ctx->preempt_ctxsw_buffer)) {
+                        err = gr_gp10b_alloc_buffer(vm,
                                         g->gr.ctx_vars.preempt_image_size,
                                         &gr_ctx->preempt_ctxsw_buffer);
-                if (err) {
-                        nvgpu_err(g, "cannot allocate preempt buffer");
-                        goto fail;
-                }
+                        if (err) {
+                                nvgpu_err(g, "cannot allocate preempt buffer");
+                                goto fail;
+                        }
 
-                err = gr_gp10b_alloc_buffer(vm,
+                        err = gr_gp10b_alloc_buffer(vm,
                                         spill_size,
                                         &gr_ctx->spill_ctxsw_buffer);
-                if (err) {
-                        nvgpu_err(g, "cannot allocate spill buffer");
-                        goto fail_free_preempt;
-                }
+                        if (err) {
+                                nvgpu_err(g, "cannot allocate spill buffer");
+                                goto fail_free_preempt;
+                        }
 
-                err = gr_gp10b_alloc_buffer(vm,
+                        err = gr_gp10b_alloc_buffer(vm,
                                         attrib_cb_size,
                                         &gr_ctx->betacb_ctxsw_buffer);
-                if (err) {
-                        nvgpu_err(g, "cannot allocate beta buffer");
-                        goto fail_free_spill;
-                }
+                        if (err) {
+                                nvgpu_err(g, "cannot allocate beta buffer");
+                                goto fail_free_spill;
+                        }
 
-                err = gr_gp10b_alloc_buffer(vm,
+                        err = gr_gp10b_alloc_buffer(vm,
                                         pagepool_size,
                                         &gr_ctx->pagepool_ctxsw_buffer);
-                if (err) {
-                        nvgpu_err(g, "cannot allocate page pool");
-                        goto fail_free_betacb;
+                        if (err) {
+                                nvgpu_err(g, "cannot allocate page pool");
+                                goto fail_free_betacb;
+                        }
                 }
 
                 gr_ctx->graphics_preempt_mode = graphics_preempt_mode;