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, 2 insertions, 1 deletions

diff --git a/drivers/gpu/nvgpu/vgpu/dbg_vgpu.c b/drivers/gpu/nvgpu/vgpu/dbg_vgpu.c
index ef12c3fd..a9533e03 100644
--- a/drivers/gpu/nvgpu/vgpu/dbg_vgpu.c
+++ b/drivers/gpu/nvgpu/vgpu/dbg_vgpu.c
@@ -26,7 +26,7 @@ static int vgpu_exec_regops(struct dbg_session_gk20a *dbg_s,
                       struct nvgpu_dbg_gpu_reg_op *ops,
                       u64 num_ops)
 {
-        struct channel_gk20a *ch = dbg_s->ch;
+        struct channel_gk20a *ch;
         struct gk20a_platform *platform = gk20a_get_platform(dbg_s->g->dev);
         struct tegra_vgpu_cmd_msg msg;
         struct tegra_vgpu_reg_ops_params *p = &msg.params.reg_ops;
@@ -55,6 +55,7 @@ static int vgpu_exec_regops(struct dbg_session_gk20a *dbg_s,
 
         msg.cmd = TEGRA_VGPU_CMD_REG_OPS;
         msg.handle = platform->virt_handle;
+        ch = nvgpu_dbg_gpu_get_session_channel(dbg_s);
         p->handle = ch ? ch->virt_ctx : 0;
         p->num_ops = num_ops;
         p->is_profiler = dbg_s->is_profiler;