[PATCH 4/7] drm/amdgpu/virt: add function to check MMIO accessing

[Pixel Ding]

From: pding <Pixel.Ding at amd.com>

MMIO space can be blocked on virtualised device. Add this function
to check if MMIO is blocked or not.

Todo: need a reliable method such like communation with hypervisor.

Signed-off-by: pding <Pixel.Ding at amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_virt.c | 5 +++++
 drivers/gpu/drm/amd/amdgpu/amdgpu_virt.h | 1 +
 2 files changed, 6 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_virt.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_virt.c
index e97f80f..33dac7e 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_virt.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_virt.c
@@ -24,6 +24,11 @@
 #include "amdgpu.h"
 #define MAX_KIQ_REG_WAIT	100000000 /* in usecs */
 
+bool amdgpu_virt_mmio_blocked(struct amdgpu_device *adev)
+{
+	return RREG32_NO_KIQ(0xc040) == 0xffffffff;
+}
+
 int amdgpu_allocate_static_csa(struct amdgpu_device *adev)
 {
 	int r;
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_virt.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_virt.h
index b89d37f..81efb9d 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_virt.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_virt.h
@@ -276,6 +276,7 @@ static inline bool is_virtual_machine(void)
 }
 
 struct amdgpu_vm;
+bool amdgpu_virt_mmio_blocked(struct amdgpu_device *adev);
 int amdgpu_allocate_static_csa(struct amdgpu_device *adev);
 int amdgpu_map_static_csa(struct amdgpu_device *adev, struct amdgpu_vm *vm,
 			  struct amdgpu_bo_va **bo_va);
-- 
2.9.5