[PATCH v2 11/24] drm/i915/slpc: Add/Update interface for requested frequency

[Sagar Arun Kamble]

From: Tom O'Rourke <Tom.O'Rourke at intel.com>

When SLPC is controlling requested frequency, the rps.cur_freq
value is not used to make the frequency request.

Requested frequency from register RPNSWREQ has the value
most recently requested by SLPC firmware. Adding new sysfs
interface gt_req_freq_mhz to know this value.
SLPC requested value needs to be made available to i915 without
reading RPNSWREQ.

v1: Replace HAS_SLPC with intel_slpc_active (Paulo)
    Avoid magic numbers (Nick)
    Use a function for repeated code (Jon)

v2: Add "SLPC Active" to i915_frequency_info output and
    don't update cur_freq as it is driver internal request. (Chris)

Signed-off-by: Tom O'Rourke <Tom.O'Rourke at intel.com>
Signed-off-by: Sagar Arun Kamble <sagar.a.kamble at intel.com>
---
 drivers/gpu/drm/i915/i915_debugfs.c |  6 ++++++
 drivers/gpu/drm/i915/i915_sysfs.c   | 33 +++++++++++++++++++++++++++++++++
 2 files changed, 39 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index a95d7bc..2ae1fff 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -1110,6 +1110,9 @@ static int i915_frequency_info(struct seq_file *m, void *unused)
 
 	intel_runtime_pm_get(dev_priv);
 
+	if (intel_slpc_active(dev_priv))
+		seq_puts(m, "SLPC Active\n");
+
 	if (IS_GEN5(dev)) {
 		u16 rgvswctl = I915_READ16(MEMSWCTL);
 		u16 rgvstat = I915_READ16(MEMSTAT_ILK);
@@ -2372,6 +2375,9 @@ static int i915_rps_boost_info(struct seq_file *m, void *data)
 	struct drm_i915_private *dev_priv = to_i915(dev);
 	struct drm_file *file;
 
+	if (intel_slpc_active(dev_priv))
+		return -ENODEV;
+
 	seq_printf(m, "RPS enabled? %d\n", dev_priv->rps.enabled);
 	seq_printf(m, "GPU busy? %s [%x]\n",
 		   yesno(dev_priv->gt.awake), dev_priv->gt.active_engines);
diff --git a/drivers/gpu/drm/i915/i915_sysfs.c b/drivers/gpu/drm/i915/i915_sysfs.c
index f1ffde7..5547f41 100644
--- a/drivers/gpu/drm/i915/i915_sysfs.c
+++ b/drivers/gpu/drm/i915/i915_sysfs.c
@@ -302,11 +302,42 @@ static ssize_t gt_cur_freq_mhz_show(struct device *kdev,
 	struct drm_device *dev = minor->dev;
 	struct drm_i915_private *dev_priv = to_i915(dev);
 
+	if (intel_slpc_active(dev_priv))
+		return -ENODEV;
+
 	return snprintf(buf, PAGE_SIZE, "%d\n",
 			intel_gpu_freq(dev_priv,
 				       dev_priv->rps.cur_freq));
 }
 
+static ssize_t gt_req_freq_mhz_show(struct device *kdev,
+				    struct device_attribute *attr, char *buf)
+{
+	struct drm_minor *minor = dev_to_drm_minor(kdev);
+	struct drm_device *dev = minor->dev;
+	struct drm_i915_private *dev_priv = to_i915(dev);
+	u32 reqf;
+
+	if (!intel_runtime_pm_get_if_in_use(dev_priv))
+		return -ENODEV;
+
+	reqf = I915_READ(GEN6_RPNSWREQ);
+	intel_runtime_pm_put(dev_priv);
+
+	if (IS_GEN9(dev))
+		reqf >>= 23;
+	else {
+		reqf &= ~GEN6_TURBO_DISABLE;
+		if (IS_HASWELL(dev) || IS_BROADWELL(dev))
+			reqf >>= 24;
+		else
+			reqf >>= 25;
+	}
+	reqf = intel_gpu_freq(dev_priv, reqf);
+
+	return snprintf(buf, PAGE_SIZE, "%d\n", reqf);
+}
+
 static ssize_t gt_boost_freq_mhz_show(struct device *kdev, struct device_attribute *attr, char *buf)
 {
 	struct drm_minor *minor = dev_to_drm_minor(kdev);
@@ -476,6 +507,7 @@ static ssize_t gt_min_freq_mhz_store(struct device *kdev,
 
 static DEVICE_ATTR(gt_act_freq_mhz, S_IRUGO, gt_act_freq_mhz_show, NULL);
 static DEVICE_ATTR(gt_cur_freq_mhz, S_IRUGO, gt_cur_freq_mhz_show, NULL);
+static DEVICE_ATTR(gt_req_freq_mhz, S_IRUGO, gt_req_freq_mhz_show, NULL);
 static DEVICE_ATTR(gt_boost_freq_mhz, S_IRUGO, gt_boost_freq_mhz_show, gt_boost_freq_mhz_store);
 static DEVICE_ATTR(gt_max_freq_mhz, S_IRUGO | S_IWUSR, gt_max_freq_mhz_show, gt_max_freq_mhz_store);
 static DEVICE_ATTR(gt_min_freq_mhz, S_IRUGO | S_IWUSR, gt_min_freq_mhz_show, gt_min_freq_mhz_store);
@@ -510,6 +542,7 @@ static ssize_t gt_rp_mhz_show(struct device *kdev, struct device_attribute *attr
 static const struct attribute *gen6_attrs[] = {
 	&dev_attr_gt_act_freq_mhz.attr,
 	&dev_attr_gt_cur_freq_mhz.attr,
+	&dev_attr_gt_req_freq_mhz.attr,
 	&dev_attr_gt_boost_freq_mhz.attr,
 	&dev_attr_gt_max_freq_mhz.attr,
 	&dev_attr_gt_min_freq_mhz.attr,
-- 
1.9.1