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

1 files changed, 1 insertions, 1 deletions

diff --git a/drivers/gpu/nvgpu/os/linux/ioctl_dbg.c b/drivers/gpu/nvgpu/os/linux/ioctl_dbg.c
index aeed07ce..dc732dc5 100644
--- a/drivers/gpu/nvgpu/os/linux/ioctl_dbg.c
+++ b/drivers/gpu/nvgpu/os/linux/ioctl_dbg.c
@@ -1112,7 +1112,7 @@ static int nvgpu_dbg_gpu_ioctl_set_mmu_debug_mode(
                 goto clean_up;
         }
 
-        err = nvgpu_tsg_set_mmu_debug_mode(tsg_gk20a_from_ch(ch), ch, enable);
+        err = nvgpu_tsg_set_mmu_debug_mode(ch, enable);
         if (err) {
                 nvgpu_err(g, "set mmu debug mode failed, err=%d", err);
         }