drm/i915/mtl: Modify CAGF functions for MTL

Update CAGF functions for MTL to get actual resolved frequency of 3D and
SAMedia.

v2: Update MTL_MIRROR_TARGET_WP1 position/formatting (MattR)
    Move MTL branches in cagf functions to top (MattR)
    Fix commit message (Andi)
v3: Added comment about registers not needing forcewake for Gen12+ and
    returning 0 freq in RC6
v4: Use REG_FIELD_GET and uncore (Rodrigo)

Bspec: 66300
Signed-off-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Signed-off-by: Badal Nilawar <badal.nilawar@intel.com>
Reviewed-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Acked-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221114123348.3474216-4-badal.nilawar@intel.com

drivers/gpu/drm/i915/gt/intel_gt_regs.h

@@ -21,6 +21,10 @@
  */
 #define PERF_REG(offset)			_MMIO(offset)
 
+/* MTL workpoint reg to get core C state and actual freq of 3D, SAMedia */
+#define MTL_MIRROR_TARGET_WP1			_MMIO(0xc60)
+#define   MTL_CAGF_MASK				REG_GENMASK(8, 0)
+
 /* RPM unit config (Gen8+) */
 #define RPM_CONFIG0				_MMIO(0xd00)
 #define   GEN9_RPM_CONFIG0_CRYSTAL_CLOCK_FREQ_SHIFT	3

drivers/gpu/drm/i915/gt/intel_rps.c

@@ -2099,7 +2099,9 @@ u32 intel_rps_get_cagf(struct intel_rps *rps, u32 rpstat)
 	struct drm_i915_private *i915 = rps_to_i915(rps);
 	u32 cagf;
 
-	if (GRAPHICS_VER(i915) >= 12)
+	if (GRAPHICS_VER_FULL(i915) >= IP_VER(12, 70))
+		cagf = REG_FIELD_GET(MTL_CAGF_MASK, rpstat);
+	else if (GRAPHICS_VER(i915) >= 12)
 		cagf = REG_FIELD_GET(GEN12_CAGF_MASK, rpstat);
 	else if (IS_VALLEYVIEW(i915) || IS_CHERRYVIEW(i915))
 		cagf = REG_FIELD_GET(RPE_MASK, rpstat);
@@ -2121,7 +2123,13 @@ static u32 read_cagf(struct intel_rps *rps)
 	struct intel_uncore *uncore = rps_to_uncore(rps);
 	u32 freq;
 
-	if (GRAPHICS_VER(i915) >= 12) {
+	/*
+	 * For Gen12+ reading freq from HW does not need a forcewake and
+	 * registers will return 0 freq when GT is in RC6
+	 */
+	if (GRAPHICS_VER_FULL(i915) >= IP_VER(12, 70)) {
+		freq = intel_uncore_read(uncore, MTL_MIRROR_TARGET_WP1);
+	} else if (GRAPHICS_VER(i915) >= 12) {
 		freq = intel_uncore_read(uncore, GEN12_RPSTAT1);
 	} else if (IS_VALLEYVIEW(i915) || IS_CHERRYVIEW(i915)) {
 		vlv_punit_get(i915);