drm/xe: Create a xe_gt_freq component for raw management and sysfs

Goals of this new xe_gt_freq component:
1. Detach sysfs controls and raw freq management from GuC SLPC.
2. Create a directory that could later be aligned with devfreq.
3. Encapsulate all the freq control in a single directory. Although
   we only have one freq domain per GT, already start with a numbered
   freq0 directory so it could be expanded in the future if multiple
   domains or PLL are needed.

Note: Although in the goal #1, the raw freq management control is
mentioned, this patch only starts by the sysfs control. The RP freq
configuration and init freq selection are still under the guc_pc, but
should be moved to this component in a follow-up patch.

v2: - Add /tile# to the doc and remove unnecessary kobject_put (Riana)
    - s/ssize_t/int on some ret variables (Vinay)

Cc: Sujaritha Sundaresan <sujaritha.sundaresan@intel.com>
Cc: Vinay Belgaumkar <vinay.belgaumkar@intel.com>
Cc: Riana Tauro <riana.tauro@intel.com>
Reviewed-by: Vinay Belgaumkar <vinay.belgaumkar@intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

1 files changed, 216 insertions, 0 deletions

diff --git a/drivers/gpu/drm/xe/xe_gt_freq.c b/drivers/gpu/drm/xe/xe_gt_freq.c
new file mode 100644
index 000000000000..2c3830d0e9e5
--- /dev/null
+++ b/drivers/gpu/drm/xe/xe_gt_freq.c
@@ -0,0 +1,216 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright © 2023 Intel Corporation
+ */
+
+#include "xe_gt_freq.h"
+
+#include <linux/kobject.h>
+#include <linux/sysfs.h>
+
+#include <drm/drm_managed.h>
+#include <drm/drm_print.h>
+
+#include "xe_device_types.h"
+#include "xe_gt_sysfs.h"
+#include "xe_guc_pc.h"
+
+/**
+ * DOC: Xe GT Frequency Management
+ *
+ * This component is responsible for the raw GT frequency management, including
+ * the sysfs API.
+ *
+ * Underneath, Xe enables GuC SLPC automated frequency management. GuC is then
+ * allowed to request PCODE any frequency between the Minimum and the Maximum
+ * selected by this component. Furthermore, it is important to highlight that
+ * PCODE is the ultimate decision maker of the actual running frequency, based
+ * on thermal and other running conditions.
+ *
+ * Xe's Freq provides a sysfs API for frequency management:
+ *
+ * device/tile#/gt#/freq0/<item>_freq *read-only* files:
+ * - act_freq: The actual resolved frequency decided by PCODE.
+ * - cur_freq: The current one requested by GuC PC to the PCODE.
+ * - rpn_freq: The Render Performance (RP) N level, which is the minimal one.
+ * - rpe_freq: The Render Performance (RP) E level, which is the efficient one.
+ * - rp0_freq: The Render Performance (RP) 0 level, which is the maximum one.
+ *
+ * device/tile#/gt#/freq0/<item>_freq *read-write* files:
+ * - min_freq: Min frequency request.
+ * - max_freq: Max frequency request.
+ *             If max <= min, then freq_min becomes a fixed frequency request.
+ */
+
+static struct xe_guc_pc *
+dev_to_pc(struct device *dev)
+{
+	return &kobj_to_gt(dev->kobj.parent)->uc.guc.pc;
+}
+
+static ssize_t act_freq_show(struct device *dev,
+			     struct device_attribute *attr, char *buf)
+{
+	struct xe_guc_pc *pc = dev_to_pc(dev);
+
+	return sysfs_emit(buf, "%d\n", xe_guc_pc_get_act_freq(pc));
+}
+static DEVICE_ATTR_RO(act_freq);
+
+static ssize_t cur_freq_show(struct device *dev,
+			     struct device_attribute *attr, char *buf)
+{
+	struct xe_guc_pc *pc = dev_to_pc(dev);
+	u32 freq;
+	ssize_t ret;
+
+	ret = xe_guc_pc_get_cur_freq(pc, &freq);
+	if (ret)
+		return ret;
+
+	return sysfs_emit(buf, "%d\n", freq);
+}
+static DEVICE_ATTR_RO(cur_freq);
+
+static ssize_t rp0_freq_show(struct device *dev,
+			     struct device_attribute *attr, char *buf)
+{
+	struct xe_guc_pc *pc = dev_to_pc(dev);
+
+	return sysfs_emit(buf, "%d\n", xe_guc_pc_get_rp0_freq(pc));
+}
+static DEVICE_ATTR_RO(rp0_freq);
+
+static ssize_t rpe_freq_show(struct device *dev,
+			     struct device_attribute *attr, char *buf)
+{
+	struct xe_guc_pc *pc = dev_to_pc(dev);
+
+	return sysfs_emit(buf, "%d\n", xe_guc_pc_get_rpe_freq(pc));
+}
+static DEVICE_ATTR_RO(rpe_freq);
+
+static ssize_t rpn_freq_show(struct device *dev,
+			     struct device_attribute *attr, char *buf)
+{
+	struct xe_guc_pc *pc = dev_to_pc(dev);
+
+	return sysfs_emit(buf, "%d\n", xe_guc_pc_get_rpn_freq(pc));
+}
+static DEVICE_ATTR_RO(rpn_freq);
+
+static ssize_t min_freq_show(struct device *dev,
+			     struct device_attribute *attr, char *buf)
+{
+	struct xe_guc_pc *pc = dev_to_pc(dev);
+	u32 freq;
+	ssize_t ret;
+
+	ret = xe_guc_pc_get_min_freq(pc, &freq);
+	if (ret)
+		return ret;
+
+	return sysfs_emit(buf, "%d\n", freq);
+}
+
+static ssize_t min_freq_store(struct device *dev, struct device_attribute *attr,
+			      const char *buff, size_t count)
+{
+	struct xe_guc_pc *pc = dev_to_pc(dev);
+	u32 freq;
+	ssize_t ret;
+
+	ret = kstrtou32(buff, 0, &freq);
+	if (ret)
+		return ret;
+
+	ret = xe_guc_pc_set_min_freq(pc, freq);
+	if (ret)
+		return ret;
+
+	return count;
+}
+static DEVICE_ATTR_RW(min_freq);
+
+static ssize_t max_freq_show(struct device *dev,
+			     struct device_attribute *attr, char *buf)
+{
+	struct xe_guc_pc *pc = dev_to_pc(dev);
+	u32 freq;
+	ssize_t ret;
+
+	ret = xe_guc_pc_get_max_freq(pc, &freq);
+	if (ret)
+		return ret;
+
+	return sysfs_emit(buf, "%d\n", freq);
+}
+
+static ssize_t max_freq_store(struct device *dev, struct device_attribute *attr,
+			      const char *buff, size_t count)
+{
+	struct xe_guc_pc *pc = dev_to_pc(dev);
+	u32 freq;
+	ssize_t ret;
+
+	ret = kstrtou32(buff, 0, &freq);
+	if (ret)
+		return ret;
+
+	ret = xe_guc_pc_set_max_freq(pc, freq);
+	if (ret)
+		return ret;
+
+	return count;
+}
+static DEVICE_ATTR_RW(max_freq);
+
+static const struct attribute *freq_attrs[] = {
+	&dev_attr_act_freq.attr,
+	&dev_attr_cur_freq.attr,
+	&dev_attr_rp0_freq.attr,
+	&dev_attr_rpe_freq.attr,
+	&dev_attr_rpn_freq.attr,
+	&dev_attr_min_freq.attr,
+	&dev_attr_max_freq.attr,
+	NULL
+};
+
+static void freq_fini(struct drm_device *drm, void *arg)
+{
+	struct kobject *kobj = arg;
+
+	sysfs_remove_files(kobj, freq_attrs);
+	kobject_put(kobj);
+}
+
+/**
+ * xe_gt_freq_init - Initialize Xe Freq component
+ * @gt: Xe GT object
+ *
+ * It needs to be initialized after GT Sysfs and GuC PC components are ready.
+ */
+void xe_gt_freq_init(struct xe_gt *gt)
+{
+	struct xe_device *xe = gt_to_xe(gt);
+	int err;
+
+	gt->freq = kobject_create_and_add("freq0", gt->sysfs);
+	if (!gt->freq) {
+		drm_warn(&xe->drm, "failed to add freq0 directory to %s, err: %d\n",
+			 kobject_name(gt->sysfs), err);
+		return;
+	}
+
+	err = drmm_add_action_or_reset(&xe->drm, freq_fini, gt->freq);
+	if (err) {
+		drm_warn(&xe->drm, "%s: drmm_add_action_or_reset failed, err: %d\n",
+			 __func__, err);
+		return;
+	}
+
+	err = sysfs_create_files(gt->freq, freq_attrs);
+	if (err)
+		drm_warn(&xe->drm,  "failed to add freq attrs to %s, err: %d\n",
+			 kobject_name(gt->freq), err);
+}