gpu: nvgpu: simplify power management

We currenlty initialize both runtime PM and pm_domains frameworks
and use pm_domain to control runtime power management of NvGPU

But since GPU has a separate rail, using pm_domain is not
strictly required
Hence remove pm_domain support and use runtime PM only for all
the power management
This also simplifies the code a lot

Initialization in gk20a_pm_init()
- if railgate_delay is set, set autosuspend delay of runtime PM
- try enabling runtime PM
- if runtime PM is now enabled, keep GPU railgated
- if runtime PM is not enabled, keep GPU unrailgated
- if can_railgate = false, disable runtime PM and keep
  GPU unrailgated

Set gk20a_pm_ops with below callbacks for runtime PM
static const struct dev_pm_ops gk20a_pm_ops = {
.runtime_resume = gk20a_pm_runtime_resume,
.runtime_suspend = gk20a_pm_runtime_suspend,
.resume = gk20a_pm_resume,
.suspend = gk20a_pm_suspend,
}

Move gk20a_busy() to use runtime checks of pm_runtime_enabled()
instead of using compile time checks on CONFIG_PM

Clean up some pm_domain related code

Remove use of gk20a_pm_enable/disable_clk() since this
should be already done in platform specific unrailgate()/
railgate() APIs

Fix "railgate_delay" and "railgate_enable" sysfs to use
runtime PM calls

For VGPU, disable runtime PM during vgpu_pm_init()
With this, we will initialize vgpu with vgpu_pm_finalize_poweron()
upon first call to gk20a_busy()

Jira DNVGPU-57

Change-Id: I6013e33ae9bd28f35c25271af1239942a4fa0919
Signed-off-by: Deepak Nibade <dnibade@nvidia.com>
Reviewed-on: http://git-master/r/1163216
Reviewed-by: Automatic_Commit_Validation_User
GVS: Gerrit_Virtual_Submit
Reviewed-by: Terje Bergstrom <tbergstrom@nvidia.com>

1 files changed, 1 insertions, 41 deletions

diff --git a/drivers/gpu/nvgpu/vgpu/vgpu.c b/drivers/gpu/nvgpu/vgpu/vgpu.c
index 6393ea50..c28130f2 100644
--- a/drivers/gpu/nvgpu/vgpu/vgpu.c
+++ b/drivers/gpu/nvgpu/vgpu/vgpu.c
@@ -430,48 +430,13 @@ done:
         return err;
 }
 
-static int vgpu_pm_initialise_domain(struct device *dev)
-{
-        struct gk20a_platform *platform = dev_get_drvdata(dev);
-        struct dev_power_governor *pm_domain_gov = NULL;
-        struct gk20a_domain_data *vgpu_pd_data;
-        struct generic_pm_domain *domain;
-
-        vgpu_pd_data = (struct gk20a_domain_data *)kzalloc
-                (sizeof(struct gk20a_domain_data), GFP_KERNEL);
-
-        if (!vgpu_pd_data)
-                return -ENOMEM;
-
-        domain = &vgpu_pd_data->gpd;
-        vgpu_pd_data->gk20a = platform->g;
-
-        domain->name = "gpu";
-
-#ifdef CONFIG_PM
-        pm_domain_gov = &pm_domain_always_on_gov;
-#endif
-
-        pm_genpd_init(domain, pm_domain_gov, true);
-
-        domain->dev_ops.save_state = vgpu_pm_prepare_poweroff;
-        domain->dev_ops.restore_state = vgpu_pm_finalize_poweron;
-
-        device_set_wakeup_capable(dev, 0);
-        return pm_genpd_add_device(domain, dev);
-}
-
 static int vgpu_pm_init(struct device *dev)
 {
         int err = 0;
 
         gk20a_dbg_fn("");
 
-        pm_runtime_enable(dev);
-
-        /* genpd will take care of runtime power management if it is enabled */
-        if (IS_ENABLED(CONFIG_PM_GENERIC_DOMAINS))
-                err = vgpu_pm_initialise_domain(dev);
+        __pm_runtime_disable(dev, false);
 
         return err;
 }
@@ -567,16 +532,11 @@ int vgpu_remove(struct platform_device *pdev)
 {
         struct device *dev = &pdev->dev;
         struct gk20a *g = get_gk20a(dev);
-        struct gk20a_domain_data *vgpu_gpd;
         gk20a_dbg_fn("");
 
         if (g->remove_support)
                 g->remove_support(dev);
 
-        vgpu_gpd = container_of(&g, struct gk20a_domain_data, gk20a);
-        vgpu_gpd->gk20a = NULL;
-        kfree(vgpu_gpd);
-
         vgpu_comm_deinit();
         gk20a_user_deinit(dev, &nvgpu_class);
         gk20a_get_platform(dev)->g = NULL;