gpu: nvgpu: Add busy/idle ref counting

Add reference counting for gk20a_busy() and gk20a_idle() so that
the driver can keep track of whether the driver is active.

Bug 1816516
Bug 1807277

Signed-off-by: Alex Waterman <alexw@nvidia.com>
Reviewed-on: http://git-master/r/1250019
(cherry picked from commit 7f558019735bb34cf00dd1ec17df1797501cff60)
Change-Id: I64c2ff1719673912ae127707e58ee557966c4d4d
Reviewed-on: http://git-master/r/1261922
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/drivers/gpu/nvgpu/gk20a/gk20a.h b/drivers/gpu/nvgpu/gk20a/gk20a.h
index f492801e..144cb37d 100644
--- a/drivers/gpu/nvgpu/gk20a/gk20a.h
+++ b/drivers/gpu/nvgpu/gk20a/gk20a.h
@@ -34,6 +34,7 @@ struct acr_desc;
 #include <linux/irqreturn.h>
 #include <linux/tegra-soc.h>
 #include <linux/version.h>
+#include <linux/atomic.h>
 
 #include "../../../arch/arm/mach-tegra/iomap.h"
 
@@ -784,6 +785,8 @@ struct gk20a {
         struct device *dev;
         struct platform_device *host1x_dev;
 
+        atomic_t usage_count;
+        int driver_is_dying;
 
         struct resource *reg_mem;
         void __iomem *regs;
@@ -1238,6 +1241,9 @@ int gk20a_do_unidle(void);
 int __gk20a_do_idle(struct device *dev, bool force_reset);
 int __gk20a_do_unidle(struct device *dev);
 
+void gk20a_driver_start_unload(struct gk20a *g);
+int gk20a_wait_for_idle(struct device *dev);
+
 #define NVGPU_GPU_ARCHITECTURE_SHIFT 4
 
 /* constructs unique and compact GPUID from nvgpu_gpu_characteristics