drm/i915: Do not export RC6p and RC6pp if they don't exist

Avoid to expose RC6 and RC6pp to the platforms that doesn't support it.
So powertop can be changed to show RC6p and RC6pp only on the platforms
they are available.

v2: Simplify by merging RC6p and RC6pp groups and respect the spec that
mentions deep and deepest RC6 on SNB and IVB although they keep disabled
by default.

v3: Remove unecessary space.

v4: RC6p and RC6pp is only for SNB and IVB; unify debug msg and use
    has_rc6p() on sanitize options instead of is gen 6 and ivb.

v5: yet another fix on has_rc6p macro. final is_gen6 or is_ivb! To make sure
    we are excluding hsw and baytrail.

References: https://bugs.freedesktop.org/show_bug.cgi?id=84524
Cc: Josh Triplett <josh.triplett@intel.com>
Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_drv.h

@@ -2184,6 +2184,8 @@ struct drm_i915_cmd_table {
 #define HAS_PSR(dev)		(IS_HASWELL(dev) || IS_BROADWELL(dev))
 #define HAS_RUNTIME_PM(dev)	(IS_GEN6(dev) || IS_HASWELL(dev) || \
 				 IS_BROADWELL(dev) || IS_VALLEYVIEW(dev))
+#define HAS_RC6(dev)		(INTEL_INFO(dev)->gen >= 6)
+#define HAS_RC6p(dev)		(INTEL_INFO(dev)->gen == 6 || IS_IVYBRIDGE(dev))
 
 #define INTEL_PCH_DEVICE_ID_MASK		0xff00
 #define INTEL_PCH_IBX_DEVICE_ID_TYPE		0x3b00

drivers/gpu/drm/i915/i915_sysfs.c

@@ -139,8 +139,6 @@ static DEVICE_ATTR(rc6pp_residency_ms, S_IRUGO, show_rc6pp_ms, NULL);
 static struct attribute *rc6_attrs[] = {
 	&dev_attr_rc6_enable.attr,
 	&dev_attr_rc6_residency_ms.attr,
-	&dev_attr_rc6p_residency_ms.attr,
-	&dev_attr_rc6pp_residency_ms.attr,
 	NULL
 };
 
@@ -148,6 +146,17 @@ static struct attribute_group rc6_attr_group = {
 	.name = power_group_name,
 	.attrs =  rc6_attrs
 };
+
+static struct attribute *rc6p_attrs[] = {
+	&dev_attr_rc6p_residency_ms.attr,
+	&dev_attr_rc6pp_residency_ms.attr,
+	NULL
+};
+
+static struct attribute_group rc6p_attr_group = {
+	.name = power_group_name,
+	.attrs =  rc6p_attrs
+};
 #endif
 
 static int l3_access_valid(struct drm_device *dev, loff_t offset)
@@ -595,12 +604,18 @@ void i915_setup_sysfs(struct drm_device *dev)
 	int ret;
 
 #ifdef CONFIG_PM
-	if (INTEL_INFO(dev)->gen >= 6) {
+	if (HAS_RC6(dev)) {
 		ret = sysfs_merge_group(&dev->primary->kdev->kobj,
 					&rc6_attr_group);
 		if (ret)
 			DRM_ERROR("RC6 residency sysfs setup failed\n");
 	}
+	if (HAS_RC6p(dev)) {
+		ret = sysfs_merge_group(&dev->primary->kdev->kobj,
+					&rc6p_attr_group);
+		if (ret)
+			DRM_ERROR("RC6p residency sysfs setup failed\n");
+	}
 #endif
 	if (HAS_L3_DPF(dev)) {
 		ret = device_create_bin_file(dev->primary->kdev, &dpf_attrs);
@@ -640,5 +655,6 @@ void i915_teardown_sysfs(struct drm_device *dev)
 	device_remove_bin_file(dev->primary->kdev,  &dpf_attrs);
 #ifdef CONFIG_PM
 	sysfs_unmerge_group(&dev->primary->kdev->kobj, &rc6_attr_group);
+	sysfs_unmerge_group(&dev->primary->kdev->kobj, &rc6p_attr_group);
 #endif
 }

drivers/gpu/drm/i915/intel_pm.c

@@ -3629,10 +3629,15 @@ static void intel_print_rc6_info(struct drm_device *dev, u32 mode)
 		else
 			mode = 0;
 	}
-	DRM_DEBUG_KMS("Enabling RC6 states: RC6 %s, RC6p %s, RC6pp %s\n",
+	if (HAS_RC6p(dev))
+		DRM_DEBUG_KMS("Enabling RC6 states: RC6 %s RC6p %s RC6pp %s\n",
 			      (mode & GEN6_RC_CTL_RC6_ENABLE) ? "on" : "off",
 			      (mode & GEN6_RC_CTL_RC6p_ENABLE) ? "on" : "off",
 			      (mode & GEN6_RC_CTL_RC6pp_ENABLE) ? "on" : "off");
+
+	else
+		DRM_DEBUG_KMS("Enabling RC6 states: RC6 %s\n",
+			      (mode & GEN6_RC_CTL_RC6_ENABLE) ? "on" : "off");
 }
 
 static int sanitize_rc6_option(const struct drm_device *dev, int enable_rc6)
@@ -3649,7 +3654,7 @@ static int sanitize_rc6_option(const struct drm_device *dev, int enable_rc6)
 	if (enable_rc6 >= 0) {
 		int mask;
 
-		if (INTEL_INFO(dev)->gen == 6 || IS_IVYBRIDGE(dev))
+		if (HAS_RC6p(dev))
 			mask = INTEL_RC6_ENABLE | INTEL_RC6p_ENABLE |
 			       INTEL_RC6pp_ENABLE;
 		else