NULL
};
+/*
+ * Scaling for multipliers (aka frequency factors).
+ * The format of the value in the register is u8.8.
+ *
+ * The presentation to userspace is inspired by the perf event framework.
+ * See:
+ * Documentation/ABI/testing/sysfs-bus-event_source-devices-events
+ * for description of:
+ * /sys/bus/event_source/devices/<pmu>/events/<event>.scale
+ *
+ * Summary: Expose two sysfs files for each multiplier.
+ *
+ * 1. File <attr> contains a raw hardware value.
+ * 2. File <attr>.scale contains the multiplicative scale factor to be
+ * used by userspace to compute the actual value.
+ *
+ * So userspace knows that to get the frequency_factor it multiplies the
+ * provided value by the specified scale factor and vice-versa.
+ *
+ * That way there is no precision loss in the kernel interface and API
+ * is future proof should one day the hardware register change to u16.u16,
+ * on some platform. (Or any other fixed point representation.)
+ *
+ * Example:
+ * File <attr> contains the value 2.5, represented as u8.8 0x0280, which
+ * is comprised of:
+ * - an integer part of 2
+ * - a fractional part of 0x80 (representing 0x80 / 2^8 == 0x80 / 256).
+ * File <attr>.scale contains a string representation of floating point
+ * value 0.00390625 (which is (1 / 256)).
+ * Userspace computes the actual value:
+ * 0x0280 * 0.00390625 -> 2.5
+ * or converts an actual value to the value to be written into <attr>:
+ * 2.5 / 0.00390625 -> 0x0280
+ */
+
+#define U8_8_VAL_MASK 0xffff
+#define U8_8_SCALE_TO_VALUE "0.00390625"
+
+static ssize_t freq_factor_scale_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buff)
+{
+ return sysfs_emit(buff, "%s\n", U8_8_SCALE_TO_VALUE);
+}
+
+static u32 media_ratio_mode_to_factor(u32 mode)
+{
+ /* 0 -> 0, 1 -> 256, 2 -> 128 */
+ return !mode ? mode : 256 / mode;
+}
+
+static ssize_t media_freq_factor_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buff)
+{
+ struct intel_gt *gt = intel_gt_sysfs_get_drvdata(dev, attr->attr.name);
+ struct intel_guc_slpc *slpc = >->uc.guc.slpc;
+ intel_wakeref_t wakeref;
+ u32 mode;
+
+ /*
+ * Retrieve media_ratio_mode from GEN6_RPNSWREQ bit 13 set by
+ * GuC. GEN6_RPNSWREQ:13 value 0 represents 1:2 and 1 represents 1:1
+ */
+ if (IS_XEHPSDV(gt->i915) &&
+ slpc->media_ratio_mode == SLPC_MEDIA_RATIO_MODE_DYNAMIC_CONTROL) {
+ /*
+ * For XEHPSDV dynamic mode GEN6_RPNSWREQ:13 does not contain
+ * the media_ratio_mode, just return the cached media ratio
+ */
+ mode = slpc->media_ratio_mode;
+ } else {
+ with_intel_runtime_pm(gt->uncore->rpm, wakeref)
+ mode = intel_uncore_read(gt->uncore, GEN6_RPNSWREQ);
+ mode = REG_FIELD_GET(GEN12_MEDIA_FREQ_RATIO, mode) ?
+ SLPC_MEDIA_RATIO_MODE_FIXED_ONE_TO_ONE :
+ SLPC_MEDIA_RATIO_MODE_FIXED_ONE_TO_TWO;
+ }
+
+ return sysfs_emit(buff, "%u\n", media_ratio_mode_to_factor(mode));
+}
+
+static ssize_t media_freq_factor_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buff, size_t count)
+{
+ struct intel_gt *gt = intel_gt_sysfs_get_drvdata(dev, attr->attr.name);
+ struct intel_guc_slpc *slpc = >->uc.guc.slpc;
+ u32 factor, mode;
+ int err;
+
+ err = kstrtou32(buff, 0, &factor);
+ if (err)
+ return err;
+
+ for (mode = SLPC_MEDIA_RATIO_MODE_DYNAMIC_CONTROL;
+ mode <= SLPC_MEDIA_RATIO_MODE_FIXED_ONE_TO_TWO; mode++)
+ if (factor == media_ratio_mode_to_factor(mode))
+ break;
+
+ if (mode > SLPC_MEDIA_RATIO_MODE_FIXED_ONE_TO_TWO)
+ return -EINVAL;
+
+ err = intel_guc_slpc_set_media_ratio_mode(slpc, mode);
+ if (!err) {
+ slpc->media_ratio_mode = mode;
+ DRM_DEBUG("Set slpc->media_ratio_mode to %d", mode);
+ }
+ return err ?: count;
+}
+
+static DEVICE_ATTR_RW(media_freq_factor);
+static struct device_attribute dev_attr_media_freq_factor_scale =
+ __ATTR(media_freq_factor.scale, 0444, freq_factor_scale_show, NULL);
+
+static const struct attribute *media_perf_power_attrs[] = {
+ &dev_attr_media_freq_factor.attr,
+ &dev_attr_media_freq_factor_scale.attr,
+ NULL
+};
+
static int intel_sysfs_rps_init(struct intel_gt *gt, struct kobject *kobj,
const struct attribute * const *attrs)
{
drm_warn(>->i915->drm,
"failed to create gt%u throttle sysfs files (%pe)",
gt->info.id, ERR_PTR(ret));
+
+ if (HAS_MEDIA_RATIO_MODE(gt->i915) && intel_uc_uses_guc_slpc(>->uc)) {
+ ret = sysfs_create_files(kobj, media_perf_power_attrs);
+ if (ret)
+ drm_warn(>->i915->drm,
+ "failed to create gt%u media_perf_power_attrs sysfs (%pe)\n",
+ gt->info.id, ERR_PTR(ret));
+ }
}
projects / users / jedix / linux-maple.git / commitdiff