drm/radeon: add helper function to support golden registers

Golden registers are arrays of register settings from the
hw team that need to be initialized at asic startup.
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/radeon/radeon.h

@@ -1946,6 +1946,9 @@ extern void radeon_gtt_location(struct radeon_device *rdev, struct radeon_mc *mc
 extern int radeon_resume_kms(struct drm_device *dev);
 extern int radeon_suspend_kms(struct drm_device *dev, pm_message_t state);
 extern void radeon_ttm_set_active_vram_size(struct radeon_device *rdev, u64 size);
+extern void radeon_program_register_sequence(struct radeon_device *rdev,
+					     const u32 *registers,
+					     const u32 array_size);
 
 /*
  * vm

drivers/gpu/drm/radeon/radeon_device.c

@@ -97,6 +97,42 @@ static const char radeon_family_name[][16] = {
 	"LAST",
 };
 
+/**
+ * radeon_program_register_sequence - program an array of registers.
+ *
+ * @rdev: radeon_device pointer
+ * @registers: pointer to the register array
+ * @array_size: size of the register array
+ *
+ * Programs an array or registers with and and or masks.
+ * This is a helper for setting golden registers.
+ */
+void radeon_program_register_sequence(struct radeon_device *rdev,
+				      const u32 *registers,
+				      const u32 array_size)
+{
+	u32 tmp, reg, and_mask, or_mask;
+	int i;
+
+	if (array_size % 3)
+		return;
+
+	for (i = 0; i < array_size; i +=3) {
+		reg = registers[i + 0];
+		and_mask = registers[i + 1];
+		or_mask = registers[i + 2];
+
+		if (and_mask == 0xffffffff) {
+			tmp = or_mask;
+		} else {
+			tmp = RREG32(reg);
+			tmp &= ~and_mask;
+			tmp |= or_mask;
+		}
+		WREG32(reg, tmp);
+	}
+}
+
 /**
  * radeon_surface_init - Clear GPU surface registers.
  *