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, 0 insertions, 1 deletions

diff --git a/drivers/gpu/nvgpu/gk20a/gk20a.h b/drivers/gpu/nvgpu/gk20a/gk20a.h
index d1ce6afb..b03e779b 100644
--- a/drivers/gpu/nvgpu/gk20a/gk20a.h
+++ b/drivers/gpu/nvgpu/gk20a/gk20a.h
@@ -647,7 +647,6 @@ struct gk20a {
         /* held while manipulating # of debug/profiler sessions present */
         /* also prevents debug sessions from attaching until released */
         struct mutex dbg_sessions_lock;
-        int dbg_sessions; /* number attached */
         int dbg_powergating_disabled_refcount; /*refcount for pg disable */
         int dbg_timeout_disabled_refcount; /*refcount for timeout disable */