gpu: nvgpu: Add synchronization to comptag alloc and clearing

Comptags allocation and clearing was not synchronized for a
buffer. Fix this race by serializing the operations with the
gk20a_dmabuf_priv lock. While doing that, add an error check in
the cbc_ctrl call.

Bug 1902982

Change-Id: Icd96f1855eb5e5340651bcc85849b5ccc199b821
Signed-off-by: Sami Kiminki <skiminki@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/1597904
Reviewed-by: Alex Waterman <alexw@nvidia.com>
Reviewed-by: Terje Bergstrom <tbergstrom@nvidia.com>
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>

1 files changed, 18 insertions, 9 deletions

diff --git a/drivers/gpu/nvgpu/common/mm/vm.c b/drivers/gpu/nvgpu/common/mm/vm.c
index c3f6b79d..ebe8e381 100644
--- a/drivers/gpu/nvgpu/common/mm/vm.c
+++ b/drivers/gpu/nvgpu/common/mm/vm.c
@@ -874,12 +874,17 @@ struct nvgpu_mapped_buf *nvgpu_vm_map(struct vm_gk20a *vm,
                  */
                 if (comptags.needs_clear) {
                         if (g->ops.ltc.cbc_ctrl) {
-                                g->ops.ltc.cbc_ctrl(
-                                        g, gk20a_cbc_op_clear,
-                                        comptags.offset,
-                                        (comptags.offset +
-                                         comptags.lines - 1));
-                                gk20a_mark_comptags_cleared(os_buf);
+                                if (gk20a_comptags_start_clear(os_buf)) {
+                                        err = g->ops.ltc.cbc_ctrl(
+                                                g, gk20a_cbc_op_clear,
+                                                comptags.offset,
+                                                (comptags.offset +
+                                                 comptags.lines - 1));
+                                        gk20a_comptags_finish_clear(
+                                                os_buf, err == 0);
+                                        if (err)
+                                                goto clean_up;
+                                }
                         } else {
                                 /*
                                  * Cleared as part of gmmu map
@@ -920,6 +925,9 @@ struct nvgpu_mapped_buf *nvgpu_vm_map(struct vm_gk20a *vm,
                 goto clean_up;
         }
 
+        if (clear_ctags)
+                clear_ctags = gk20a_comptags_start_clear(os_buf);
+
         map_addr = g->ops.mm.gmmu_map(vm,
                                       map_addr,
                                       sgt,
@@ -935,14 +943,15 @@ struct nvgpu_mapped_buf *nvgpu_vm_map(struct vm_gk20a *vm,
                                       false,
                                       batch,
                                       aperture);
+
+        if (clear_ctags)
+                gk20a_comptags_finish_clear(os_buf, map_addr != 0);
+
         if (!map_addr) {
                 err = -ENOMEM;
                 goto clean_up;
         }
 
-        if (clear_ctags)
-                gk20a_mark_comptags_cleared(os_buf);
-
         nvgpu_init_list_node(&mapped_buffer->buffer_list);
         nvgpu_ref_init(&mapped_buffer->ref);
         mapped_buffer->addr         = map_addr;