drm/i915: Add helpers for managing rps thresholds

In preparation for exposing via sysfs add helpers for managing rps
thresholds.

v2:
* Force sw and hw re-programming on threshold change.

Signed-off-by: Tvrtko Ursulin <[e-mail]>
Cc: Rodrigo Vivi <[e-mail]>
Reviewed-by: Rodrigo Vivi <[e-mail]>
Reviewed-by: Andi Shyti <[e-mail]>
Link: https://patchwork.freedesktop.org/patch/msgid/[e-mail]

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

···
 #include "intel_gt.h"
 #include "intel_gt_clock_utils.h"
 #include "intel_gt_irq.h"
+#include "intel_gt_pm.h"
 #include "intel_gt_pm_irq.h"
+#include "intel_gt_print.h"
 #include "intel_gt_regs.h"
 #include "intel_mchbar_regs.h"
 #include "intel_pcode.h"
···
 		return intel_guc_slpc_set_min_freq(slpc, val);
 	else
 		return set_min_freq(rps, val);
+}
+
+u8 intel_rps_get_up_threshold(struct intel_rps *rps)
+{
+	return rps->power.up_threshold;
+}
+
+static int rps_set_threshold(struct intel_rps *rps, u8 *threshold, u8 val)
+{
+	int ret;
+
+	if (val > 100)
+		return -EINVAL;
+
+	ret = mutex_lock_interruptible(&rps->lock);
+	if (ret)
+		return ret;
+
+	if (*threshold == val)
+		goto out_unlock;
+
+	*threshold = val;
+
+	/* Force reset. */
+	rps->last_freq = -1;
+	mutex_lock(&rps->power.mutex);
+	rps->power.mode = -1;
+	mutex_unlock(&rps->power.mutex);
+
+	intel_rps_set(rps, clamp(rps->cur_freq,
+				 rps->min_freq_softlimit,
+				 rps->max_freq_softlimit));
+
+out_unlock:
+	mutex_unlock(&rps->lock);
+
+	return ret;
+}
+
+int intel_rps_set_up_threshold(struct intel_rps *rps, u8 threshold)
+{
+	return rps_set_threshold(rps, &rps->power.up_threshold, threshold);
+}
+
+u8 intel_rps_get_down_threshold(struct intel_rps *rps)
+{
+	return rps->power.down_threshold;
+}
+
+int intel_rps_set_down_threshold(struct intel_rps *rps, u8 threshold)
+{
+	return rps_set_threshold(rps, &rps->power.down_threshold, threshold);
 }
 
 static void intel_rps_set_manual(struct intel_rps *rps, bool enable)

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

···
 
 int intel_gpu_freq(struct intel_rps *rps, int val);
 int intel_freq_opcode(struct intel_rps *rps, int val);
+u8 intel_rps_get_up_threshold(struct intel_rps *rps);
+int intel_rps_set_up_threshold(struct intel_rps *rps, u8 threshold);
+u8 intel_rps_get_down_threshold(struct intel_rps *rps);
+int intel_rps_set_down_threshold(struct intel_rps *rps, u8 threshold);
 u32 intel_rps_read_actual_frequency(struct intel_rps *rps);
 u32 intel_rps_read_actual_frequency_fw(struct intel_rps *rps);
 u32 intel_rps_get_requested_frequency(struct intel_rps *rps);