drm/amdgpu: add 64bit doorbell functions (v2)

Newer asics need 64 bit doorbells.

v2: fix comment (Nils)

Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Ken Wang <Qingqing.Wang@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/amdgpu.h

@@ -1521,6 +1521,8 @@ void amdgpu_io_wreg(struct amdgpu_device *adev, u32 reg, u32 v);
 
 u32 amdgpu_mm_rdoorbell(struct amdgpu_device *adev, u32 index);
 void amdgpu_mm_wdoorbell(struct amdgpu_device *adev, u32 index, u32 v);
+u64 amdgpu_mm_rdoorbell64(struct amdgpu_device *adev, u32 index);
+void amdgpu_mm_wdoorbell64(struct amdgpu_device *adev, u32 index, u64 v);
 
 /*
  * Registers read & write functions.
@@ -1575,6 +1577,8 @@ void amdgpu_mm_wdoorbell(struct amdgpu_device *adev, u32 index, u32 v);
 
 #define RDOORBELL32(index) amdgpu_mm_rdoorbell(adev, (index))
 #define WDOORBELL32(index, v) amdgpu_mm_wdoorbell(adev, (index), (v))
+#define RDOORBELL64(index) amdgpu_mm_rdoorbell64(adev, (index))
+#define WDOORBELL64(index, v) amdgpu_mm_wdoorbell64(adev, (index), (v))
 
 #define REG_FIELD_SHIFT(reg, field) reg##__##field##__SHIFT
 #define REG_FIELD_MASK(reg, field) reg##__##field##_MASK

drivers/gpu/drm/amd/amdgpu/amdgpu_device.c

@@ -194,6 +194,44 @@ void amdgpu_mm_wdoorbell(struct amdgpu_device *adev, u32 index, u32 v)
 	}
 }
 
+/**
+ * amdgpu_mm_rdoorbell64 - read a doorbell Qword
+ *
+ * @adev: amdgpu_device pointer
+ * @index: doorbell index
+ *
+ * Returns the value in the doorbell aperture at the
+ * requested doorbell index (VEGA10+).
+ */
+u64 amdgpu_mm_rdoorbell64(struct amdgpu_device *adev, u32 index)
+{
+	if (index < adev->doorbell.num_doorbells) {
+		return atomic64_read((atomic64_t *)(adev->doorbell.ptr + index));
+	} else {
+		DRM_ERROR("reading beyond doorbell aperture: 0x%08x!\n", index);
+		return 0;
+	}
+}
+
+/**
+ * amdgpu_mm_wdoorbell64 - write a doorbell Qword
+ *
+ * @adev: amdgpu_device pointer
+ * @index: doorbell index
+ * @v: value to write
+ *
+ * Writes @v to the doorbell aperture at the
+ * requested doorbell index (VEGA10+).
+ */
+void amdgpu_mm_wdoorbell64(struct amdgpu_device *adev, u32 index, u64 v)
+{
+	if (index < adev->doorbell.num_doorbells) {
+		atomic64_set((atomic64_t *)(adev->doorbell.ptr + index), v);
+	} else {
+		DRM_ERROR("writing beyond doorbell aperture: 0x%08x!\n", index);
+	}
+}
+
 /**
  * amdgpu_invalid_rreg - dummy reg read function
  *