gpu: nvgpu: use refcnt for ch mmu_debug_mode

Replaced ch->mmu_debug_mode_enabled with ch->mmu_debug_mode_refcnt.
If channel is enabled multiple times by userspace, then ref count is
updated accordingly. There is an expectation that enable/disable
calls are balanced for setting channel's mmu debug mode.
When unbinding the channel, decrease refcnt for the channel until it
reaches 0.
Also, removed tsg parameter from nvgpu_tsg_set_mmu_debug_mode as it
can be retrieved from ch.

Bug 2515097
Bug 2713590

Change-Id: If334e374a55bd14ae219edbfd3b1fce5ff25c226
Signed-off-by: Thomas Fleury <tfleury@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/2184702
(cherry picked from commit f422aee39387a5aa337de69cc21a67f16697ae0e)
Reviewed-on: https://git-master.nvidia.com/r/c/linux-nvgpu/+/2208772
Reviewed-by: Automatic_Commit_Validation_User
Reviewed-by: Kajetan Dutka <kdutka@nvidia.com>
Reviewed-by: Alex Waterman <alexw@nvidia.com>
Reviewed-by: Winnie Hsu <whsu@nvidia.com>
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: Kajetan Dutka <kdutka@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>
GVS: Gerrit_Virtual_Submit

2 files changed, 6 insertions, 3 deletions

diff --git a/drivers/gpu/nvgpu/include/nvgpu/channel.h b/drivers/gpu/nvgpu/include/nvgpu/channel.h
index e98af09b..764d047c 100644
--- a/drivers/gpu/nvgpu/include/nvgpu/channel.h
+++ b/drivers/gpu/nvgpu/include/nvgpu/channel.h
@@ -328,7 +328,11 @@ struct channel_gk20a {
         bool has_os_fence_framework_support;
 
         bool is_privileged_channel;
-        bool mmu_debug_mode_enabled;
+
+        /**
+         * MMU Debugger Mode is enabled for this channel if refcnt > 0
+         */
+        u32 mmu_debug_mode_refcnt;
 };
 
 static inline struct channel_gk20a *
diff --git a/drivers/gpu/nvgpu/include/nvgpu/tsg.h b/drivers/gpu/nvgpu/include/nvgpu/tsg.h
index b43a6b98..7cd97c97 100644
--- a/drivers/gpu/nvgpu/include/nvgpu/tsg.h
+++ b/drivers/gpu/nvgpu/include/nvgpu/tsg.h
@@ -127,7 +127,6 @@ gk20a_event_id_data_from_event_id_node(struct nvgpu_list_node *node)
                 ((uintptr_t)node - offsetof(struct gk20a_event_id_data, event_id_node));
 };
 
-int nvgpu_tsg_set_mmu_debug_mode(struct tsg_gk20a *tsg,
-                struct channel_gk20a *ch, bool enable);
+int nvgpu_tsg_set_mmu_debug_mode(struct channel_gk20a *ch, bool enable);
 
 #endif /* TSG_GK20A_H */