[PATCH] drm/xe/guc_pc: Add ignore efficient frequency support

[Sk Anirban <sk.anirban@intel.com>]

When setting the minimum frequency, GuC automatically adjusts it to
efficient levels, potentially overriding user requests.
This patch adds the slpc_ignore_eff_freq sysfs interface to disable
this behavior, allowing users to enforce their exact minimum frequency
settings.

Signed-off-by: Sk Anirban <sk.anirban@intel.com>
---
 drivers/gpu/drm/xe/xe_gt_freq.c      | 36 ++++++++++++++++++++
 drivers/gpu/drm/xe/xe_guc_pc.c       | 49 ++++++++++++++++++++++++++--
 drivers/gpu/drm/xe/xe_guc_pc.h       |  1 +
 drivers/gpu/drm/xe/xe_guc_pc_types.h |  2 ++
 4 files changed, 86 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/xe/xe_gt_freq.c b/drivers/gpu/drm/xe/xe_gt_freq.c
index 4ff1b6b58d6b..fb16fa5c6a0f 100644
--- a/drivers/gpu/drm/xe/xe_gt_freq.c
+++ b/drivers/gpu/drm/xe/xe_gt_freq.c
@@ -227,6 +227,41 @@ static ssize_t max_freq_store(struct kobject *kobj,
 }
 static struct kobj_attribute attr_max_freq = __ATTR_RW(max_freq);
 
+static ssize_t slpc_ignore_eff_freq_show(struct kobject *kobj,
+					 struct kobj_attribute *attr, char *buf)
+{
+	struct device *dev = kobj_to_dev(kobj);
+	struct xe_guc_pc *pc = dev_to_pc(dev);
+
+	return sysfs_emit(buf, "%u\n", pc->ignore_eff_freq);
+}
+
+static ssize_t slpc_ignore_eff_freq_store(struct kobject *kobj,
+					  struct kobj_attribute *attr,
+					  const char *buff, size_t count)
+{
+	struct device *dev = kobj_to_dev(kobj);
+	struct xe_guc_pc *pc = dev_to_pc(dev);
+	u32 val;
+	ssize_t ret;
+
+	ret = kstrtou32(buff, 0, &val);
+	if (ret)
+		return ret;
+
+	if (val > 1)
+		return -EINVAL;
+
+	xe_pm_runtime_get(dev_to_xe(dev));
+	ret = xe_guc_pc_set_ignore_eff_freq(pc, val);
+	xe_pm_runtime_put(dev_to_xe(dev));
+	if (ret)
+		return ret;
+
+	return count;
+}
+static struct kobj_attribute attr_slpc_ignore_eff_freq = __ATTR_RW(slpc_ignore_eff_freq);
+
 static ssize_t power_profile_show(struct kobject *kobj,
 				  struct kobj_attribute *attr,
 				  char *buff)
@@ -263,6 +298,7 @@ static const struct attribute *freq_attrs[] = {
 	&attr_rpn_freq.attr,
 	&attr_min_freq.attr,
 	&attr_max_freq.attr,
+	&attr_slpc_ignore_eff_freq.attr,
 	&attr_power_profile.attr,
 	NULL
 };
diff --git a/drivers/gpu/drm/xe/xe_guc_pc.c b/drivers/gpu/drm/xe/xe_guc_pc.c
index 53fdf59524c4..0229a89e3ff8 100644
--- a/drivers/gpu/drm/xe/xe_guc_pc.c
+++ b/drivers/gpu/drm/xe/xe_guc_pc.c
@@ -336,6 +336,8 @@ static void pc_set_cur_freq(struct xe_guc_pc *pc, u32 freq)
 
 static int pc_set_min_freq(struct xe_guc_pc *pc, u32 freq)
 {
+	int ret;
+
 	/*
 	 * Let's only check for the rpn-rp0 range. If max < min,
 	 * min becomes a fixed request.
@@ -347,8 +349,10 @@ static int pc_set_min_freq(struct xe_guc_pc *pc, u32 freq)
 	 * GuC policy is to elevate minimum frequency to the efficient levels
 	 * Our goal is to have the admin choices respected.
 	 */
-	pc_action_set_param(pc, SLPC_PARAM_IGNORE_EFFICIENT_FREQUENCY,
-			    freq < pc->rpe_freq);
+	ret = pc_action_set_param(pc, SLPC_PARAM_IGNORE_EFFICIENT_FREQUENCY,
+				  freq < pc->rpe_freq || pc->ignore_eff_freq);
+	if (ret)
+		xe_gt_err(pc_to_gt(pc), "Failed to set efficient freq\n");
 
 	return pc_action_set_param(pc,
 				   SLPC_PARAM_GLOBAL_MIN_GT_UNSLICE_FREQ_MHZ,
@@ -737,6 +741,45 @@ int xe_guc_pc_set_max_freq(struct xe_guc_pc *pc, u32 freq)
 	return xe_guc_pc_set_max_freq_locked(pc, freq);
 }
 
+int xe_guc_pc_set_ignore_eff_freq(struct xe_guc_pc *pc, bool val)
+{
+	int ret;
+	u32 min_freq;
+
+	guard(mutex)(&pc->freq_lock);
+
+	if (!pc->freq_ready)
+		return -EAGAIN;
+
+	if (val) {
+		ret = xe_guc_pc_get_min_freq_locked(pc, &min_freq);
+		if (ret)
+			return ret;
+	}
+
+	ret = pc_action_set_param(pc, SLPC_PARAM_IGNORE_EFFICIENT_FREQUENCY, val);
+	if (ret) {
+		xe_gt_err(pc_to_gt(pc), "Failed to set ignore efficient freq(%d): %pe\n",
+			  val, ERR_PTR(ret));
+		return ret;
+	}
+
+	pc->ignore_eff_freq = val;
+
+	if (val) {
+		ret = pc_action_set_param(pc,
+					  SLPC_PARAM_GLOBAL_MIN_GT_UNSLICE_FREQ_MHZ,
+					  min_freq);
+		if (ret) {
+			xe_gt_err(pc_to_gt(pc), "Failed to set min freq to %u: %pe\n",
+				  min_freq, ERR_PTR(ret));
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
 /**
  * xe_guc_pc_c_status - get the current GT C state
  * @pc: XE_GuC_PC instance
@@ -1382,6 +1425,8 @@ int xe_guc_pc_init(struct xe_guc_pc *pc)
 	if (err)
 		return err;
 
+	pc->ignore_eff_freq = false;
+
 	bo = xe_managed_bo_create_pin_map(xe, tile, size,
 					  XE_BO_FLAG_VRAM_IF_DGFX(tile) |
 					  XE_BO_FLAG_GGTT |
diff --git a/drivers/gpu/drm/xe/xe_guc_pc.h b/drivers/gpu/drm/xe/xe_guc_pc.h
index 0e31396f103c..3a87d0da609d 100644
--- a/drivers/gpu/drm/xe/xe_guc_pc.h
+++ b/drivers/gpu/drm/xe/xe_guc_pc.h
@@ -31,6 +31,7 @@ int xe_guc_pc_get_min_freq(struct xe_guc_pc *pc, u32 *freq);
 int xe_guc_pc_set_min_freq(struct xe_guc_pc *pc, u32 freq);
 int xe_guc_pc_get_max_freq(struct xe_guc_pc *pc, u32 *freq);
 int xe_guc_pc_set_max_freq(struct xe_guc_pc *pc, u32 freq);
+int xe_guc_pc_set_ignore_eff_freq(struct xe_guc_pc *pc, bool val);
 int xe_guc_pc_set_power_profile(struct xe_guc_pc *pc, const char *buf);
 void xe_guc_pc_get_power_profile(struct xe_guc_pc *pc, char *profile);
 
diff --git a/drivers/gpu/drm/xe/xe_guc_pc_types.h b/drivers/gpu/drm/xe/xe_guc_pc_types.h
index 5e4ea53fbee6..c3b44598507b 100644
--- a/drivers/gpu/drm/xe/xe_guc_pc_types.h
+++ b/drivers/gpu/drm/xe/xe_guc_pc_types.h
@@ -37,6 +37,8 @@ struct xe_guc_pc {
 	struct mutex freq_lock;
 	/** @freq_ready: Only handle freq changes, if they are really ready */
 	bool freq_ready;
+	/** @ignore_eff_freq: Ignore efficient frequency */
+	bool ignore_eff_freq;
 	/** @power_profile: Base or power_saving profile */
 	u32 power_profile;
 };
-- 
2.43.0