gpu: nvgpu: replace tsg list mutex with rwsem

Lock only for modifications to the tsg channel list, and allow multiple
concurrent readers.

Bug 1848834
Bug 1814773

Change-Id: Ie3938d4239cfe36a14211f4649ce72b7fc3e2fa4
Signed-off-by: Konsta Holtta <kholtta@nvidia.com>
Reviewed-on: http://git-master/r/1269579
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>

1 files changed, 9 insertions, 9 deletions

diff --git a/drivers/gpu/nvgpu/gk20a/tsg_gk20a.c b/drivers/gpu/nvgpu/gk20a/tsg_gk20a.c
index 0541f430..8e6f763a 100644
--- a/drivers/gpu/nvgpu/gk20a/tsg_gk20a.c
+++ b/drivers/gpu/nvgpu/gk20a/tsg_gk20a.c
@@ -43,11 +43,11 @@ int gk20a_enable_tsg(struct tsg_gk20a *tsg)
         struct gk20a *g = tsg->g;
         struct channel_gk20a *ch;
 
-        mutex_lock(&tsg->ch_list_lock);
+        down_read(&tsg->ch_list_lock);
         list_for_each_entry(ch, &tsg->ch_list, ch_entry) {
                 g->ops.fifo.enable_channel(ch);
         }
-        mutex_unlock(&tsg->ch_list_lock);
+        up_read(&tsg->ch_list_lock);
 
         return 0;
 }
@@ -57,11 +57,11 @@ int gk20a_disable_tsg(struct tsg_gk20a *tsg)
         struct gk20a *g = tsg->g;
         struct channel_gk20a *ch;
 
-        mutex_lock(&tsg->ch_list_lock);
+        down_read(&tsg->ch_list_lock);
         list_for_each_entry(ch, &tsg->ch_list, ch_entry) {
                 g->ops.fifo.disable_channel(ch);
         }
-        mutex_unlock(&tsg->ch_list_lock);
+        up_read(&tsg->ch_list_lock);
 
         return 0;
 }
@@ -126,9 +126,9 @@ int gk20a_tsg_bind_channel(struct tsg_gk20a *tsg,
                 return -EINVAL;
         }
 
-        mutex_lock(&tsg->ch_list_lock);
+        down_write(&tsg->ch_list_lock);
         list_add_tail(&ch->ch_entry, &tsg->ch_list);
-        mutex_unlock(&tsg->ch_list_lock);
+        up_write(&tsg->ch_list_lock);
 
         kref_get(&tsg->refcount);
 
@@ -144,9 +144,9 @@ int gk20a_tsg_unbind_channel(struct channel_gk20a *ch)
         struct fifo_gk20a *f = &ch->g->fifo;
         struct tsg_gk20a *tsg = &f->tsg[ch->tsgid];
 
-        mutex_lock(&tsg->ch_list_lock);
+        down_write(&tsg->ch_list_lock);
         list_del_init(&ch->ch_entry);
-        mutex_unlock(&tsg->ch_list_lock);
+        up_write(&tsg->ch_list_lock);
 
         kref_put(&tsg->refcount, gk20a_tsg_release);
 
@@ -168,7 +168,7 @@ int gk20a_init_tsg_support(struct gk20a *g, u32 tsgid)
         tsg->tsgid = tsgid;
 
         INIT_LIST_HEAD(&tsg->ch_list);
-        mutex_init(&tsg->ch_list_lock);
+        init_rwsem(&tsg->ch_list_lock);
 
         INIT_LIST_HEAD(&tsg->event_id_list);
         mutex_init(&tsg->event_id_list_lock);