gpu: nvgpu: rework secure_page allocation path

Currently, if can_railgate = false, then we have below
sequence to allocate secure_page
- unrailgate GPU (forever)
- reset_assert()
- allocate secure_page
- reset_deassert()

But if we allocate secure page even before unrailgating GPU
for first time, then we can avoid reset_assert()/deassert()
calls since GPU should already be in reset/railgated at
boot time

hence, rework this sequence as below
- init required mutex, set platform->reset_control
- allocate secure page (GPU should already be in reset
  at this point)
- gk20a_pm_init() which unrailgates GPU in case of
  can_railgate = false

Bug 200137963
Bug 1678611

Change-Id: I79d0543bb5cf1eaf1009e1e6ac142532d84514a5
Signed-off-by: Deepak Nibade <dnibade@nvidia.com>
Reviewed-on: http://git-master/r/797153
(cherry picked from commit 368004501943d38c003747f6bec0384fed57ee65)
Reviewed-on: http://git-master/r/816005
GVS: Gerrit_Virtual_Submit
Reviewed-by: Terje Bergstrom <tbergstrom@nvidia.com>

1 files changed, 12 insertions, 19 deletions

diff --git a/drivers/gpu/nvgpu/gk20a/gk20a.c b/drivers/gpu/nvgpu/gk20a/gk20a.c
index 0cc29026..fd7fdee1 100644
--- a/drivers/gpu/nvgpu/gk20a/gk20a.c
+++ b/drivers/gpu/nvgpu/gk20a/gk20a.c
@@ -1275,8 +1275,6 @@ static int gk20a_pm_init(struct platform_device *dev)
 
         gk20a_dbg_fn("");
 
-        mutex_init(&platform->railgate_lock);
-
         /* Initialise pm runtime */
         if (platform->clockgate_delay) {
                 pm_runtime_set_autosuspend_delay(&dev->dev,
@@ -1299,10 +1297,6 @@ static int gk20a_pm_init(struct platform_device *dev)
         if (IS_ENABLED(CONFIG_PM_GENERIC_DOMAINS))
                 err = gk20a_pm_initialise_domain(dev);
 
-        platform->reset_control = devm_reset_control_get(&dev->dev, NULL);
-        if (IS_ERR(platform->reset_control))
-                platform->reset_control = NULL;
-
         return err;
 }
 
@@ -1312,17 +1306,11 @@ static int gk20a_secure_page_alloc(struct platform_device *pdev)
         int err = 0;
 
         if (platform->secure_page_alloc) {
-                if (platform->num_clks > 0)
-                        tegra_periph_reset_assert(platform->clk[0]);
-                udelay(10);
                 err = platform->secure_page_alloc(pdev);
-                if (platform->num_clks > 0)
-                        tegra_periph_reset_deassert(platform->clk[0]);
+                if (!err)
+                        platform->secure_alloc_ready = true;
         }
 
-        if (!err)
-                platform->secure_alloc_ready = true;
-
         return err;
 }
 
@@ -1413,9 +1401,14 @@ static int gk20a_probe(struct platform_device *dev)
         gk20a_init_support(dev);
 
         init_rwsem(&gk20a->busy_lock);
+        mutex_init(&platform->railgate_lock);
 
         spin_lock_init(&gk20a->mc_enable_lock);
 
+        platform->reset_control = devm_reset_control_get(&dev->dev, NULL);
+        if (IS_ERR(platform->reset_control))
+                platform->reset_control = NULL;
+
         gk20a_debug_init(dev);
 
         /* Initialize the platform interface. */
@@ -1425,6 +1418,11 @@ static int gk20a_probe(struct platform_device *dev)
                 return err;
         }
 
+        err = gk20a_secure_page_alloc(dev);
+        if (err)
+                dev_err(&dev->dev,
+                        "failed to allocate secure buffer %d\n", err);
+
         err = gk20a_pm_init(dev);
         if (err) {
                 dev_err(&dev->dev, "pm init failed");
@@ -1445,11 +1443,6 @@ static int gk20a_probe(struct platform_device *dev)
                 }
         }
 
-        err = gk20a_secure_page_alloc(dev);
-        if (err)
-                dev_err(&dev->dev,
-                        "failed to allocate secure buffer %d\n", err);
-
         /* Set DMA parameters to allow larger sgt lists */
         dev->dev.dma_parms = &gk20a->dma_parms;
         dma_set_max_seg_size(&dev->dev, UINT_MAX);