gpu: nvgpu: Add platform flag to disable ASPM

Add a platform flag and logic to disable ASPM on boot if a
platform does not want ASPM enabled.

Bug 200256272

Change-Id: I378997290377ef8ffa21bf8e7f3f59fa134b3d4d
Signed-off-by: Alex Waterman <alexw@nvidia.com>
Reviewed-on: http://git-master/r/1263271
(cherry picked from commit 01e4700b74f4b4c6f0b9ffb40747653f2b63ea3c)
Reviewed-on: http://git-master/r/1274477
GVS: Gerrit_Virtual_Submit
Reviewed-by: Terje Bergstrom <tbergstrom@nvidia.com>

3 files changed, 7 insertions, 0 deletions

diff --git a/drivers/gpu/nvgpu/gk20a/gk20a.c b/drivers/gpu/nvgpu/gk20a/gk20a.c
index bed728cf..77d708dd 100644
--- a/drivers/gpu/nvgpu/gk20a/gk20a.c
+++ b/drivers/gpu/nvgpu/gk20a/gk20a.c
@@ -1084,6 +1084,9 @@ int gk20a_pm_finalize_poweron(struct device *dev)
         if (g->ops.xve.available_speeds) {
                 u32 speed;
 
+                if (platform->disable_aspm && g->ops.xve.disable_aspm)
+                        g->ops.xve.disable_aspm(g);
+
                 g->ops.xve.sw_init(dev);
                 g->ops.xve.available_speeds(g, &speed);
 
diff --git a/drivers/gpu/nvgpu/gk20a/gk20a.h b/drivers/gpu/nvgpu/gk20a/gk20a.h
index dc130e33..9e0dd64a 100644
--- a/drivers/gpu/nvgpu/gk20a/gk20a.h
+++ b/drivers/gpu/nvgpu/gk20a/gk20a.h
@@ -744,6 +744,7 @@ struct gpu_ops {
                 void (*available_speeds)(struct gk20a *g, u32 *speed_mask);
                 u32 (*xve_readl)(struct gk20a *g, u32 reg);
                 void (*xve_writel)(struct gk20a *g, u32 reg, u32 val);
+                void (*disable_aspm)(struct gk20a *g);
         } xve;
 };
 
diff --git a/drivers/gpu/nvgpu/gk20a/platform_gk20a.h b/drivers/gpu/nvgpu/gk20a/platform_gk20a.h
index 2b17d32a..c2aec6e3 100644
--- a/drivers/gpu/nvgpu/gk20a/platform_gk20a.h
+++ b/drivers/gpu/nvgpu/gk20a/platform_gk20a.h
@@ -61,6 +61,9 @@ struct gk20a_platform {
         /* flag to set sync destroy aggressiveness */
         bool aggressive_sync_destroy;
 
+        /* set if ASPM should be disabled on boot; only makes sense for PCI */
+        bool disable_aspm;
+
         /* Should be populated by probe. */
         struct dentry *debugfs;
         struct dentry *debugfs_alias;