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, 15 insertions, 6 deletions

diff --git a/drivers/gpu/nvgpu/gk20a/channel_gk20a.c b/drivers/gpu/nvgpu/gk20a/channel_gk20a.c
index b7bccd07..e0beefb1 100644
--- a/drivers/gpu/nvgpu/gk20a/channel_gk20a.c
+++ b/drivers/gpu/nvgpu/gk20a/channel_gk20a.c
@@ -857,6 +857,8 @@ static void gk20a_free_channel(struct channel_gk20a *ch)
         struct vm_gk20a *ch_vm = ch->vm;
         unsigned long timeout = gk20a_get_gr_idle_timeout(g);
         struct dbg_session_gk20a *dbg_s;
+        struct dbg_session_data *session_data, *tmp_s;
+        struct dbg_session_channel_data *ch_data, *tmp;
         bool was_reset;
 
         gk20a_dbg_fn("");
@@ -992,14 +994,21 @@ unbind:
         WARN_ON(ch->sync);
 
         /* unlink all debug sessions */
-        mutex_lock(&ch->dbg_s_lock);
-
-        list_for_each_entry(dbg_s, &ch->dbg_s_list, dbg_s_list_node) {
-                dbg_s->ch = NULL;
-                list_del_init(&dbg_s->dbg_s_list_node);
+        mutex_lock(&g->dbg_sessions_lock);
+
+        list_for_each_entry_safe(session_data, tmp_s,
+                                &ch->dbg_s_list, dbg_s_entry) {
+                dbg_s = session_data->dbg_s;
+                mutex_lock(&dbg_s->ch_list_lock);
+                list_for_each_entry_safe(ch_data, tmp,
+                                        &dbg_s->ch_list, ch_entry) {
+                        if (ch_data->chid == ch->hw_chid)
+                                dbg_unbind_single_channel_gk20a(dbg_s, ch_data);
+                }
+                mutex_unlock(&dbg_s->ch_list_lock);
         }
 
-        mutex_unlock(&ch->dbg_s_lock);
+        mutex_unlock(&g->dbg_sessions_lock);
 
 release:
         /* make sure we catch accesses of unopened channels in case