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>

5 files changed, 16 insertions, 110 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)
diff --git a/drivers/gpu/nvgpu/gk20a/channel_gk20a.c b/drivers/gpu/nvgpu/gk20a/channel_gk20a.c
index bcc05079..eaea5a77 100644
--- a/drivers/gpu/nvgpu/gk20a/channel_gk20a.c
+++ b/drivers/gpu/nvgpu/gk20a/channel_gk20a.c
@@ -726,7 +726,6 @@ int gk20a_channel_release(struct inode *inode, struct file *filp)
         gk20a_free_channel(ch, true);
         gk20a_idle(ch->g->dev);
 
-        gk20a_put_client(g);
         filp->private_data = NULL;
         return 0;
 }
@@ -788,23 +787,14 @@ static int __gk20a_channel_open(struct gk20a *g, struct file *filp)
 
         trace_gk20a_channel_open(dev_name(&g->dev->dev));
 
-        err = gk20a_get_client(g);
-        if (err) {
-                gk20a_err(dev_from_gk20a(g),
-                        "failed to get client ref");
-                return err;
-        }
-
         err = gk20a_busy(g->dev);
         if (err) {
-                gk20a_put_client(g);
                 gk20a_err(dev_from_gk20a(g), "failed to power on, %d", err);
                 return err;
         }
         ch = gk20a_open_new_channel(g);
         gk20a_idle(g->dev);
         if (!ch) {
-                gk20a_put_client(g);
                 gk20a_err(dev_from_gk20a(g),
                         "failed to get f");
                 return -ENOMEM;
diff --git a/drivers/gpu/nvgpu/gk20a/ctrl_gk20a.c b/drivers/gpu/nvgpu/gk20a/ctrl_gk20a.c
index 6969a3a7..fbc93fc3 100644
--- a/drivers/gpu/nvgpu/gk20a/ctrl_gk20a.c
+++ b/drivers/gpu/nvgpu/gk20a/ctrl_gk20a.c
@@ -25,7 +25,6 @@
 
 int gk20a_ctrl_dev_open(struct inode *inode, struct file *filp)
 {
-        int err;
         struct gk20a *g;
 
         gk20a_dbg_fn("");
@@ -35,22 +34,13 @@ int gk20a_ctrl_dev_open(struct inode *inode, struct file *filp)
 
         filp->private_data = g->dev;
 
-        err = gk20a_get_client(g);
-        if (err) {
-                gk20a_dbg_fn("fail to get channel!");
-                return err;
-        }
-
         return 0;
 }
 
 int gk20a_ctrl_dev_release(struct inode *inode, struct file *filp)
 {
-        struct platform_device *dev = filp->private_data;
-
         gk20a_dbg_fn("");
 
-        gk20a_put_client(get_gk20a(dev));
         return 0;
 }
 
@@ -177,21 +167,15 @@ static int gk20a_ctrl_alloc_as(
         }
         fd_install(fd, file);
 
-        err = gk20a_get_client(g);
-        if (err)
-                goto clean_up;
-
         err = gk20a_as_alloc_share(&g->as, args->big_page_size, &as_share);
         if (err)
-                goto clean_up_client;
+                goto clean_up;
 
         file->private_data = as_share;
 
         args->as_fd = fd;
         return 0;
 
-clean_up_client:
-        gk20a_put_client(g);
 clean_up:
         put_unused_fd(fd);
         return err;
diff --git a/drivers/gpu/nvgpu/gk20a/gk20a.c b/drivers/gpu/nvgpu/gk20a/gk20a.c
index a09a0631..98dce955 100644
--- a/drivers/gpu/nvgpu/gk20a/gk20a.c
+++ b/drivers/gpu/nvgpu/gk20a/gk20a.c
@@ -734,72 +734,6 @@ static int gk20a_init_support(struct platform_device *dev)
         return err;
 }
 
-static int gk20a_init_client(struct platform_device *dev)
-{
-        struct gk20a *g = get_gk20a(dev);
-        struct gk20a_platform *platform = gk20a_get_platform(dev);
-        int err;
-
-        gk20a_dbg_fn("");
-
-        if (platform->virtual_dev) {
-                err = vgpu_pm_finalize_poweron(&dev->dev);
-                if (err)
-                        return err;
-        }
-
-#ifndef CONFIG_PM_RUNTIME
-        gk20a_pm_finalize_poweron(&dev->dev);
-#endif
-
-        err = gk20a_init_mm_setup_sw(g);
-        if (err)
-                return err;
-
-        if (IS_ENABLED(CONFIG_GK20A_DEVFREQ))
-                gk20a_scale_hw_init(dev);
-        return 0;
-}
-
-static void gk20a_deinit_client(struct platform_device *dev)
-{
-        struct gk20a_platform *platform = gk20a_get_platform(dev);
-
-        gk20a_dbg_fn("");
-
-        if (platform->virtual_dev) {
-                vgpu_pm_prepare_poweroff(&dev->dev);
-                return;
-        }
-
-#ifndef CONFIG_PM_RUNTIME
-        gk20a_pm_prepare_poweroff(&dev->dev);
-#endif
-}
-
-int gk20a_get_client(struct gk20a *g)
-{
-        int err = 0;
-
-        mutex_lock(&g->client_lock);
-        if (g->client_refcount == 0)
-                err = gk20a_init_client(g->dev);
-        if (!err)
-                g->client_refcount++;
-        mutex_unlock(&g->client_lock);
-        return err;
-}
-
-void gk20a_put_client(struct gk20a *g)
-{
-        mutex_lock(&g->client_lock);
-        if (g->client_refcount == 1)
-                gk20a_deinit_client(g->dev);
-        g->client_refcount--;
-        mutex_unlock(&g->client_lock);
-        WARN_ON(g->client_refcount < 0);
-}
-
 static int gk20a_pm_prepare_poweroff(struct device *dev)
 {
         struct platform_device *pdev = to_platform_device(dev);
@@ -1662,6 +1596,14 @@ int gk20a_busy(struct platform_device *pdev)
                 if (platform->idle)
                         platform->idle(pdev);
         }
+#else
+        if (!g->power_on) {
+                ret = platform->virtual_dev ?
+                        vgpu_pm_finalize_poweron(&dev->dev)
+                        : gk20a_pm_finalize_poweron(&dev->dev);
+                if (ret)
+                        goto fail;
+        }
 #endif
         gk20a_scale_notify_busy(pdev);
 
diff --git a/drivers/gpu/nvgpu/gk20a/gk20a.h b/drivers/gpu/nvgpu/gk20a/gk20a.h
index 04a4cf66..20afd2bd 100644
--- a/drivers/gpu/nvgpu/gk20a/gk20a.h
+++ b/drivers/gpu/nvgpu/gk20a/gk20a.h
@@ -710,8 +710,6 @@ void gk20a_idle(struct platform_device *pdev);
 void gk20a_disable(struct gk20a *g, u32 units);
 void gk20a_enable(struct gk20a *g, u32 units);
 void gk20a_reset(struct gk20a *g, u32 units);
-int gk20a_get_client(struct gk20a *g);
-void gk20a_put_client(struct gk20a *g);
 int __gk20a_do_idle(struct platform_device *pdev);
 int __gk20a_do_unidle(struct platform_device *pdev);