gpu: nvgpu: support binding multiple channels to a debug session

We currently bind only one channel to a debug session
But some use cases might need multiple channels bound
to same debug session

Add this support by adding a list of channels to debug session.
List structure is implemented as struct dbg_session_channel_data

List node dbg_s_list_node is currently defined in struct
dbg_session_gk20a. But this is inefficient when we need to
add debug session to multiple channels

Hence add new reference structure dbg_session_data to
store dbg_session pointer and list entry

For each NVGPU_DBG_GPU_IOCTL_BIND_CHANNEL call, create
two reference structure dbg_session_channel_data for channel
and dbg_session_data for debug session and bind them together

Define API nvgpu_dbg_gpu_get_session_channel() which will
get first channel in the list of debug session
Use this API wherever we refer to channel bound to debug
session

Remove dbg_sessions define in struct gk20a since it is
not being used anywhere

Add new API NVGPU_DBG_GPU_IOCTL_UNBIND_CHANNEL to support
unbinding of channel from debug sesssion

Bug 200156699

Change-Id: I3bfa6f9cd5b90e7254a75c7e64ac893739776b7f
Signed-off-by: Deepak Nibade <dnibade@nvidia.com>
Reviewed-on: http://git-master/r/1120331
GVS: Gerrit_Virtual_Submit
Reviewed-by: Terje Bergstrom <tbergstrom@nvidia.com>

1 files changed, 22 insertions, 4 deletions

diff --git a/drivers/gpu/nvgpu/gk20a/dbg_gpu_gk20a.h b/drivers/gpu/nvgpu/gk20a/dbg_gpu_gk20a.h
index 0ff6cfb3..d569a6cd 100644
--- a/drivers/gpu/nvgpu/gk20a/dbg_gpu_gk20a.h
+++ b/drivers/gpu/nvgpu/gk20a/dbg_gpu_gk20a.h
@@ -31,6 +31,9 @@ int gk20a_prof_gpu_dev_open(struct inode *inode, struct file *filp);
 /* used by the interrupt handler to post events */
 void gk20a_dbg_gpu_post_events(struct channel_gk20a *fault_ch);
 
+struct channel_gk20a *
+nvgpu_dbg_gpu_get_session_channel(struct dbg_session_gk20a *dbg_s);
+
 struct dbg_gpu_session_ops {
         int (*exec_reg_ops)(struct dbg_session_gk20a *dbg_s,
                             struct nvgpu_dbg_gpu_reg_op *ops,
@@ -68,22 +71,37 @@ struct dbg_session_gk20a {
         struct device             *dev;
         struct gk20a              *g;
 
-        /* bound channel, if any */
-        struct file          *ch_f;
-        struct channel_gk20a *ch;
+        /* list of bound channels, if any */
+        struct list_head ch_list;
+        struct mutex ch_list_lock;
 
         /* session operations */
         struct dbg_gpu_session_ops *ops;
 
         /* event support */
         struct dbg_gpu_session_events dbg_events;
-        struct list_head dbg_s_list_node;
 
         bool broadcast_stop_trigger;
 };
 
+struct dbg_session_data {
+        struct dbg_session_gk20a *dbg_s;
+        struct list_head dbg_s_entry;
+};
+
+struct dbg_session_channel_data {
+        struct file          *ch_f;
+        int channel_fd;
+        int chid;
+        struct list_head ch_entry;
+        struct dbg_session_data *session_data;
+};
+
 extern struct dbg_gpu_session_ops dbg_gpu_session_ops_gk20a;
 
+int dbg_unbind_single_channel_gk20a(struct dbg_session_gk20a *dbg_s,
+                        struct dbg_session_channel_data *ch_data);
+
 bool gk20a_dbg_gpu_broadcast_stop_trigger(struct channel_gk20a *ch);
 int gk20a_dbg_gpu_clear_broadcast_stop_trigger(struct channel_gk20a *ch);