5 files changed, 64 insertions, 5 deletions

diff --git a/drivers/gpu/nvgpu/common/fifo/tsg.c b/drivers/gpu/nvgpu/common/fifo/tsg.c
index 6d6c322e..5883667f 100644
--- a/drivers/gpu/nvgpu/common/fifo/tsg.c
+++ b/drivers/gpu/nvgpu/common/fifo/tsg.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2014-2019, NVIDIA CORPORATION.  All rights reserved.
+ * Copyright (c) 2014-2020, 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"),
@@ -445,3 +445,49 @@ void gk20a_tsg_update_sm_error_state_locked(struct tsg_gk20a *tsg,
         tsg_sm_error_states->hww_warp_esr_report_mask =
                         sm_error_state->hww_warp_esr_report_mask;
 }
+
+int nvgpu_tsg_set_mmu_debug_mode(struct tsg_gk20a *tsg,
+                struct channel_gk20a *ch, bool enable)
+{
+        struct gk20a *g;
+        int err = 0;
+        u32 tsg_refcnt;
+
+        if ((ch == NULL) || (tsg == NULL)) {
+                return -EINVAL;
+        }
+        g = ch->g;
+
+        if (g->ops.gr.set_mmu_debug_mode == NULL) {
+                return -ENOSYS;
+        }
+
+        if (enable) {
+                if (ch->mmu_debug_mode_enabled) {
+                        /* already enabled for this channel */
+                        return 0;
+                }
+                tsg_refcnt = tsg->mmu_debug_mode_refcnt + 1U;
+        } else {
+                if (!ch->mmu_debug_mode_enabled) {
+                        /* already disabled for this channel */
+                        return 0;
+                }
+                tsg_refcnt = tsg->mmu_debug_mode_refcnt - 1U;
+        }
+
+        /*
+         * enable GPC MMU debug mode if it was requested for at
+         * least one channel in the TSG
+         */
+        err = g->ops.gr.set_mmu_debug_mode(g, ch, tsg_refcnt > 0U);
+        if (err != 0) {
+                nvgpu_err(g, "set mmu debug mode failed, err=%d", err);
+                return err;
+        }
+
+        ch->mmu_debug_mode_enabled = enable;
+        tsg->mmu_debug_mode_refcnt = tsg_refcnt;
+
+        return err;
+}
diff --git a/drivers/gpu/nvgpu/gm20b/gr_gm20b.c b/drivers/gpu/nvgpu/gm20b/gr_gm20b.c
index d00181af..dacef784 100644
--- a/drivers/gpu/nvgpu/gm20b/gr_gm20b.c
+++ b/drivers/gpu/nvgpu/gm20b/gr_gm20b.c
@@ -1468,10 +1468,15 @@ int gm20b_gr_set_mmu_debug_mode(struct gk20a *g,
                         gr_gpcs_pri_mmu_debug_ctrl_debug_disabled_f(),
         };
         int err;
+        struct tsg_gk20a *tsg = tsg_gk20a_from_ch(ch);
+
+        if (tsg == NULL) {
+                return enable ? -EINVAL : 0;
+        }
 
         err = gr_gk20a_exec_ctx_ops(ch, &ctx_ops, 1, 1, 0, NULL);
         if (err != 0) {
-                nvgpu_err(g, "Failed to access register");
+                nvgpu_err(g, "update MMU debug mode failed");
         }
         return err;
 }
diff --git a/drivers/gpu/nvgpu/include/nvgpu/channel.h b/drivers/gpu/nvgpu/include/nvgpu/channel.h
index 7ca60fe3..e98af09b 100644
--- a/drivers/gpu/nvgpu/include/nvgpu/channel.h
+++ b/drivers/gpu/nvgpu/include/nvgpu/channel.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018-2019, NVIDIA CORPORATION.  All rights reserved.
+ * Copyright (c) 2018-2020, 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"),
@@ -328,6 +328,7 @@ struct channel_gk20a {
         bool has_os_fence_framework_support;
 
         bool is_privileged_channel;
+        bool mmu_debug_mode_enabled;
 };
 
 static inline struct channel_gk20a *
diff --git a/drivers/gpu/nvgpu/include/nvgpu/tsg.h b/drivers/gpu/nvgpu/include/nvgpu/tsg.h
index 212fb77c..b43a6b98 100644
--- a/drivers/gpu/nvgpu/include/nvgpu/tsg.h
+++ b/drivers/gpu/nvgpu/include/nvgpu/tsg.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2014-2018, NVIDIA CORPORATION.  All rights reserved.
+ * Copyright (c) 2014-2020, 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"),
@@ -76,6 +76,9 @@ struct tsg_gk20a {
         bool tpc_num_initialized;
         bool in_use;
 
+        /* MMU debug mode enabled if mmu_debug_mode_refcnt > 0 */
+        u32  mmu_debug_mode_refcnt;
+
         struct nvgpu_tsg_sm_error_state *sm_error_states;
 
 #define NVGPU_SM_EXCEPTION_TYPE_MASK_NONE               (0x0U)
@@ -124,4 +127,7 @@ 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);
+
 #endif /* TSG_GK20A_H */
diff --git a/drivers/gpu/nvgpu/os/linux/ioctl_dbg.c b/drivers/gpu/nvgpu/os/linux/ioctl_dbg.c
index f7a65f2b..408bbc64 100644
--- a/drivers/gpu/nvgpu/os/linux/ioctl_dbg.c
+++ b/drivers/gpu/nvgpu/os/linux/ioctl_dbg.c
@@ -1107,10 +1107,11 @@ static int nvgpu_dbg_gpu_ioctl_set_mmu_debug_mode(
         ch = nvgpu_dbg_gpu_get_session_channel(dbg_s);
         if (!ch) {
                 nvgpu_err(g, "no bound channel for mmu debug mode");
+                err = -EINVAL;
                 goto clean_up;
         }
 
-        err = g->ops.gr.set_mmu_debug_mode(g, ch, enable);
+        err = nvgpu_tsg_set_mmu_debug_mode(tsg_gk20a_from_ch(ch), ch, enable);
         if (err) {
                 nvgpu_err(g, "set mmu debug mode failed, err=%d", err);
         }