drm/radeon: add get_allowed_info_register for SI

Registers that can be fetched from the info ioctl.

Tested-by: Marek Olšák <marek.olsak@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
diff --git a/drivers/gpu/drm/radeon/si.c b/drivers/gpu/drm/radeon/si.c
index e088e55..0d2295f 100644
--- a/drivers/gpu/drm/radeon/si.c
+++ b/drivers/gpu/drm/radeon/si.c
@@ -1264,6 +1264,36 @@
 	}
 }
 
+/**
+ * si_get_allowed_info_register - fetch the register for the info ioctl
+ *
+ * @rdev: radeon_device pointer
+ * @reg: register offset in bytes
+ * @val: register value
+ *
+ * Returns 0 for success or -EINVAL for an invalid register
+ *
+ */
+int si_get_allowed_info_register(struct radeon_device *rdev,
+				 u32 reg, u32 *val)
+{
+	switch (reg) {
+	case GRBM_STATUS:
+	case GRBM_STATUS2:
+	case GRBM_STATUS_SE0:
+	case GRBM_STATUS_SE1:
+	case SRBM_STATUS:
+	case SRBM_STATUS2:
+	case (DMA_STATUS_REG + DMA0_REGISTER_OFFSET):
+	case (DMA_STATUS_REG + DMA1_REGISTER_OFFSET):
+	case UVD_STATUS:
+		*val = RREG32(reg);
+		return 0;
+	default:
+		return -EINVAL;
+	}
+}
+
 #define PCIE_BUS_CLK                10000
 #define TCLK                        (PCIE_BUS_CLK / 10)