gpu: nvgpu: Remove get and put client routines

gk20a_get_client() and gk20a_put_client() routines are effectively dead
code. The GPU has been using pm_runtime for reference counting whether
the device should be turned on or off, and gk20a_get_client() and
gk20a_put_client() have had no positive effect on the behaviour.

In worst case these functions trigger some issues as they may trigger
code paths that should not be run. There is also a race between get/put
and busy/idle.

This patch removes the functions and reworks as_gk20a.c to correctly use
gk20a_busy()/gk20a_idle() where put/get was required.

Additionally, finalize_poweron() is moved to gk20a_busy(), similarly as
it was with gk20a_get_client(). If pm_runtime is not in use, the device
is only powered on and never off. Currently this affects vgpu power
management since it does not use pm_runtime yet.

Bug 1562096

Change-Id: I3162655f83457e9caccd9264eed36b5d51e60c52
Signed-off-by: Arto Merilainen <amerilainen@nvidia.com>
Signed-off-by: Konsta Holtta <kholtta@nvidia.com>
Reviewed-on: http://git-master/r/414998
Reviewed-by: Automatic_Commit_Validation_User
Reviewed-by: Seshendra Gadagottu <sgadagottu@nvidia.com>
Tested-by: Seshendra Gadagottu <sgadagottu@nvidia.com>
GVS: Gerrit_Virtual_Submit
Reviewed-by: Terje Bergstrom <tbergstrom@nvidia.com>

1 files changed, 7 insertions, 15 deletions

diff --git a/drivers/gpu/nvgpu/gk20a/as_gk20a.c b/drivers/gpu/nvgpu/gk20a/as_gk20a.c
index 74d83a7d..27608cec 100644
--- a/drivers/gpu/nvgpu/gk20a/as_gk20a.c
+++ b/drivers/gpu/nvgpu/gk20a/as_gk20a.c
@@ -56,14 +56,19 @@ int gk20a_as_alloc_share(struct gk20a_as *as,
         as_share->ref_cnt.counter = 1;
 
         /* this will set as_share->vm. */
+        err = gk20a_busy(g->dev);
+        if (err)
+                goto failed;
         err = g->ops.mm.vm_alloc_share(as_share, flags);
+        gk20a_idle(g->dev);
+
         if (err)
                 goto failed;
 
         *out = as_share;
         return 0;
 
- failed:
+failed:
         kfree(as_share);
         return err;
 }
@@ -180,16 +185,9 @@ int gk20a_as_dev_open(struct inode *inode, struct file *filp)
 
         g = container_of(inode->i_cdev, struct gk20a, as.cdev);
 
-        err = gk20a_get_client(g);
-        if (err) {
-                gk20a_dbg_fn("fail to get channel!");
-                return err;
-        }
-
         err = gk20a_as_alloc_share(&g->as, 0, &as_share);
         if (err) {
                 gk20a_dbg_fn("failed to alloc share");
-                gk20a_put_client(g);
                 return err;
         }
 
@@ -200,16 +198,10 @@ int gk20a_as_dev_open(struct inode *inode, struct file *filp)
 int gk20a_as_dev_release(struct inode *inode, struct file *filp)
 {
         struct gk20a_as_share *as_share = filp->private_data;
-        int ret;
-        struct gk20a *g = gk20a_from_as(as_share->as);
 
         gk20a_dbg_fn("");
 
-        ret = gk20a_as_release_share(as_share);
-
-        gk20a_put_client(g);
-
-        return ret;
+        return gk20a_as_release_share(as_share);
 }
 
 long gk20a_as_dev_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)