soc: hisilicon: kunpeng_hccs: Support low power feature for the specified HCCS type

Add the low power feature for the specified HCCS type by increasing
and decreasing the used lane number of these HCCS ports on platform.

Signed-off-by: Huisong Li <lihuisong@huawei.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Wei Xu <xuwei5@hisilicon.com>

Documentation/ABI/testing/sysfs-devices-platform-kunpeng_hccs

@@ -87,3 +87,40 @@ Contact:	Huisong Li <lihuisong@huawei.com>
 Description:
 		This interface is used to show all HCCS types used on the
 		platform, like, HCCS-v1, HCCS-v2 and so on.
+
+What:		/sys/devices/platform/HISI04Bx:00/available_inc_dec_lane_types
+What:		/sys/devices/platform/HISI04Bx:00/dec_lane_of_type
+What:		/sys/devices/platform/HISI04Bx:00/inc_lane_of_type
+Date:		August 2024
+KernelVersion:	6.12
+Contact:	Huisong Li <lihuisong@huawei.com>
+Description:
+		These interfaces under /sys/devices/platform/HISI04Bx/ are
+		used to support the low power consumption feature of some
+		HCCS types by changing the number of lanes used. The interfaces
+		changing the number of lanes used are 'dec_lane_of_type' and
+		'inc_lane_of_type' which require root privileges. These
+		interfaces aren't exposed if no HCCS type on platform support
+		this feature. Please note that decreasing lane number is only
+		allowed if all the specified HCCS ports are not busy.
+
+		The low power consumption interfaces are as follows:
+
+		============================= ==== ================================
+		available_inc_dec_lane_types: (RO) available HCCS types (string) to
+						   increase and decrease the number
+						   of lane used, e.g. HCCS-v2.
+		dec_lane_of_type:             (WO) input HCCS type supported
+						   decreasing lane to decrease the
+						   used lane number of all specified
+						   HCCS type ports on platform to
+						   the minimum.
+						   You can query the 'cur_lane_num'
+						   to get the minimum lane number
+						   after executing successfully.
+		inc_lane_of_type:             (WO) input HCCS type supported
+						   increasing lane to increase the
+						   used lane number of all specified
+						   HCCS type ports on platform to
+						   the full lane state.
+		============================= ==== ================================

drivers/soc/hisilicon/Kconfig

@@ -13,9 +13,12 @@ config KUNPENG_HCCS
 	  interconnection bus protocol.
 	  The performance of application may be affected if some HCCS
 	  ports are not in full lane status, have a large number of CRC
-	  errors and so on.
+	  errors and so on. This may support for reducing system power
+	  consumption if there are HCCS ports supported low power feature
+	  on platform.
 
 	  Say M here if you want to include support for querying the
-	  health status and port information of HCCS on Kunpeng SoC.
+	  health status and port information of HCCS, or reducing system
+	  power consumption on Kunpeng SoC.
 
 endmenu

drivers/soc/hisilicon/kunpeng_hccs.c

@@ -23,10 +23,18 @@
  *    - CRC error count sum
  *
  * - Retrieve all HCCS types used on the platform.
+ *
+ * - Support low power feature for all specified HCCS type ports, and
+ *   provide the following interface:
+ *    - query HCCS types supported increasing and decreasing lane number.
+ *    - decrease lane number of all specified HCCS type ports on idle state.
+ *    - increase lane number of all specified HCCS type ports.
  */
 #include <linux/acpi.h>
+#include <linux/delay.h>
 #include <linux/iopoll.h>
 #include <linux/platform_device.h>
+#include <linux/stringify.h>
 #include <linux/sysfs.h>
 #include <linux/types.h>
 
@@ -65,6 +73,33 @@ static struct hccs_dev *device_kobj_to_hccs_dev(struct kobject *k)
 	return platform_get_drvdata(pdev);
 }
 
+static char *hccs_port_type_to_name(struct hccs_dev *hdev, u8 type)
+{
+	u16 i;
+
+	for (i = 0; i < hdev->used_type_num; i++) {
+		if (hdev->type_name_maps[i].type == type)
+			return hdev->type_name_maps[i].name;
+	}
+
+	return NULL;
+}
+
+static int hccs_name_to_port_type(struct hccs_dev *hdev,
+				  const char *name, u8 *type)
+{
+	u16 i;
+
+	for (i = 0; i < hdev->used_type_num; i++) {
+		if (strcmp(hdev->type_name_maps[i].name, name) == 0) {
+			*type = hdev->type_name_maps[i].type;
+			return 0;
+		}
+	}
+
+	return -EINVAL;
+}
+
 struct hccs_register_ctx {
 	struct device *dev;
 	u8 chan_id;
@@ -1195,6 +1230,306 @@ static const struct kobj_type hccs_chip_type = {
 	.default_groups = hccs_chip_default_groups,
 };
 
+static int hccs_parse_pm_port_type(struct hccs_dev *hdev, const char *buf,
+				   u8 *port_type)
+{
+	char hccs_name[HCCS_NAME_MAX_LEN + 1] = "";
+	u8 type;
+	int ret;
+
+	ret = sscanf(buf, "%" __stringify(HCCS_NAME_MAX_LEN) "s", hccs_name);
+	if (ret != 1)
+		return -EINVAL;
+
+	ret = hccs_name_to_port_type(hdev, hccs_name, &type);
+	if (ret) {
+		dev_dbg(hdev->dev, "input invalid, please get the available types from 'used_types'.\n");
+		return ret;
+	}
+
+	if (type == HCCS_V2 && hdev->caps & HCCS_CAPS_HCCS_V2_PM) {
+		*port_type = type;
+		return 0;
+	}
+
+	dev_dbg(hdev->dev, "%s doesn't support for increasing and decreasing lane.\n",
+		hccs_name);
+
+	return -EOPNOTSUPP;
+}
+
+static int hccs_query_port_idle_status(struct hccs_dev *hdev,
+				       struct hccs_port_info *port, u8 *idle)
+{
+	const struct hccs_die_info *die = port->die;
+	const struct hccs_chip_info *chip = die->chip;
+	struct hccs_port_comm_req_param *req_param;
+	struct hccs_desc desc;
+	int ret;
+
+	hccs_init_req_desc(&desc);
+	req_param = (struct hccs_port_comm_req_param *)desc.req.data;
+	req_param->chip_id = chip->chip_id;
+	req_param->die_id = die->die_id;
+	req_param->port_id = port->port_id;
+	ret = hccs_pcc_cmd_send(hdev, HCCS_GET_PORT_IDLE_STATUS, &desc);
+	if (ret) {
+		dev_err(hdev->dev,
+			"get port idle status failed, ret = %d.\n", ret);
+		return ret;
+	}
+
+	*idle = *((u8 *)desc.rsp.data);
+	return 0;
+}
+
+static int hccs_get_all_spec_port_idle_sta(struct hccs_dev *hdev, u8 port_type,
+					   bool *all_idle)
+{
+	struct hccs_chip_info *chip;
+	struct hccs_port_info *port;
+	struct hccs_die_info *die;
+	int ret = 0;
+	u8 i, j, k;
+	u8 idle;
+
+	*all_idle = false;
+	for (i = 0; i < hdev->chip_num; i++) {
+		chip = &hdev->chips[i];
+		for (j = 0; j < chip->die_num; j++) {
+			die = &chip->dies[j];
+			for (k = 0; k < die->port_num; k++) {
+				port = &die->ports[k];
+				if (port->port_type != port_type)
+					continue;
+				ret = hccs_query_port_idle_status(hdev, port,
+								  &idle);
+				if (ret) {
+					dev_err(hdev->dev,
+						"hccs%u on chip%u/die%u get idle status failed, ret = %d.\n",
+						k, i, j, ret);
+					return ret;
+				} else if (idle == 0) {
+					dev_info(hdev->dev, "hccs%u on chip%u/die%u is busy.\n",
+						k, i, j);
+					return 0;
+				}
+			}
+		}
+	}
+	*all_idle = true;
+
+	return 0;
+}
+
+static int hccs_get_all_spec_port_full_lane_sta(struct hccs_dev *hdev,
+						u8 port_type, bool *full_lane)
+{
+	struct hccs_link_status status = {0};
+	struct hccs_chip_info *chip;
+	struct hccs_port_info *port;
+	struct hccs_die_info *die;
+	u8 i, j, k;
+	int ret;
+
+	*full_lane = false;
+	for (i = 0; i < hdev->chip_num; i++) {
+		chip = &hdev->chips[i];
+		for (j = 0; j < chip->die_num; j++) {
+			die = &chip->dies[j];
+			for (k = 0; k < die->port_num; k++) {
+				port = &die->ports[k];
+				if (port->port_type != port_type)
+					continue;
+				ret = hccs_query_port_link_status(hdev, port,
+								  &status);
+				if (ret)
+					return ret;
+				if (status.lane_num != port->max_lane_num)
+					return 0;
+			}
+		}
+	}
+	*full_lane = true;
+
+	return 0;
+}
+
+static int hccs_prepare_inc_lane(struct hccs_dev *hdev, u8 type)
+{
+	struct hccs_inc_lane_req_param *req_param;
+	struct hccs_desc desc;
+	int ret;
+
+	hccs_init_req_desc(&desc);
+	req_param = (struct hccs_inc_lane_req_param *)desc.req.data;
+	req_param->port_type = type;
+	req_param->opt_type = HCCS_PREPARE_INC_LANE;
+	ret = hccs_pcc_cmd_send(hdev, HCCS_PM_INC_LANE, &desc);
+	if (ret)
+		dev_err(hdev->dev, "prepare for increasing lane failed, ret = %d.\n",
+			ret);
+
+	return ret;
+}
+
+static int hccs_wait_serdes_adapt_completed(struct hccs_dev *hdev, u8 type)
+{
+#define HCCS_MAX_WAIT_CNT_FOR_ADAPT	10
+#define HCCS_QUERY_ADAPT_RES_DELAY_MS	100
+#define HCCS_SERDES_ADAPT_OK		0
+
+	struct hccs_inc_lane_req_param *req_param;
+	u8 wait_cnt = HCCS_MAX_WAIT_CNT_FOR_ADAPT;
+	struct hccs_desc desc;
+	u8 adapt_res;
+	int ret;
+
+	do {
+		hccs_init_req_desc(&desc);
+		req_param = (struct hccs_inc_lane_req_param *)desc.req.data;
+		req_param->port_type = type;
+		req_param->opt_type = HCCS_GET_ADAPT_RES;
+		ret = hccs_pcc_cmd_send(hdev, HCCS_PM_INC_LANE, &desc);
+		if (ret) {
+			dev_err(hdev->dev, "query adapting result failed, ret = %d.\n",
+				ret);
+			return ret;
+		}
+		adapt_res = *((u8 *)&desc.rsp.data);
+		if (adapt_res == HCCS_SERDES_ADAPT_OK)
+			return 0;
+
+		msleep(HCCS_QUERY_ADAPT_RES_DELAY_MS);
+	} while (--wait_cnt);
+
+	dev_err(hdev->dev, "wait for adapting completed timeout.\n");
+
+	return -ETIMEDOUT;
+}
+
+static int hccs_start_hpcs_retraining(struct hccs_dev *hdev, u8 type)
+{
+	struct hccs_inc_lane_req_param *req_param;
+	struct hccs_desc desc;
+	int ret;
+
+	hccs_init_req_desc(&desc);
+	req_param = (struct hccs_inc_lane_req_param *)desc.req.data;
+	req_param->port_type = type;
+	req_param->opt_type = HCCS_START_RETRAINING;
+	ret = hccs_pcc_cmd_send(hdev, HCCS_PM_INC_LANE, &desc);
+	if (ret)
+		dev_err(hdev->dev, "start hpcs retraining failed, ret = %d.\n",
+			ret);
+
+	return ret;
+}
+
+static int hccs_start_inc_lane(struct hccs_dev *hdev, u8 type)
+{
+	int ret;
+
+	ret = hccs_prepare_inc_lane(hdev, type);
+	if (ret)
+		return ret;
+
+	ret = hccs_wait_serdes_adapt_completed(hdev, type);
+	if (ret)
+		return ret;
+
+	return hccs_start_hpcs_retraining(hdev, type);
+}
+
+static int hccs_start_dec_lane(struct hccs_dev *hdev, u8 type)
+{
+	struct hccs_desc desc;
+	u8 *port_type;
+	int ret;
+
+	hccs_init_req_desc(&desc);
+	port_type = (u8 *)desc.req.data;
+	*port_type = type;
+	ret = hccs_pcc_cmd_send(hdev, HCCS_PM_DEC_LANE, &desc);
+	if (ret)
+		dev_err(hdev->dev, "start to decrease lane failed, ret = %d.\n",
+			ret);
+
+	return ret;
+}
+
+static ssize_t dec_lane_of_type_store(struct kobject *kobj, struct kobj_attribute *attr,
+			      const char *buf, size_t count)
+{
+	struct hccs_dev *hdev = device_kobj_to_hccs_dev(kobj);
+	bool all_in_idle;
+	u8 port_type;
+	int ret;
+
+	ret = hccs_parse_pm_port_type(hdev, buf, &port_type);
+	if (ret)
+		return ret;
+
+	mutex_lock(&hdev->lock);
+	ret = hccs_get_all_spec_port_idle_sta(hdev, port_type, &all_in_idle);
+	if (ret)
+		goto out;
+	if (!all_in_idle) {
+		ret = -EBUSY;
+		dev_err(hdev->dev, "please don't decrese lanes on high load with %s, ret = %d.\n",
+			hccs_port_type_to_name(hdev, port_type), ret);
+		goto out;
+	}
+
+	ret = hccs_start_dec_lane(hdev, port_type);
+out:
+	mutex_unlock(&hdev->lock);
+
+	return ret == 0 ? count : ret;
+}
+static struct kobj_attribute dec_lane_of_type_attr =
+		__ATTR(dec_lane_of_type, 0200, NULL, dec_lane_of_type_store);
+
+static ssize_t inc_lane_of_type_store(struct kobject *kobj, struct kobj_attribute *attr,
+			      const char *buf, size_t count)
+{
+	struct hccs_dev *hdev = device_kobj_to_hccs_dev(kobj);
+	bool full_lane;
+	u8 port_type;
+	int ret;
+
+	ret = hccs_parse_pm_port_type(hdev, buf, &port_type);
+	if (ret)
+		return ret;
+
+	mutex_lock(&hdev->lock);
+	ret = hccs_get_all_spec_port_full_lane_sta(hdev, port_type, &full_lane);
+	if (ret || full_lane)
+		goto out;
+
+	ret = hccs_start_inc_lane(hdev, port_type);
+out:
+	mutex_unlock(&hdev->lock);
+	return ret == 0 ? count : ret;
+}
+static struct kobj_attribute inc_lane_of_type_attr =
+		__ATTR(inc_lane_of_type, 0200, NULL, inc_lane_of_type_store);
+
+static ssize_t available_inc_dec_lane_types_show(struct kobject *kobj,
+						 struct kobj_attribute *attr,
+						 char *buf)
+{
+	struct hccs_dev *hdev = device_kobj_to_hccs_dev(kobj);
+
+	if (hdev->caps & HCCS_CAPS_HCCS_V2_PM)
+		return sysfs_emit(buf, "%s\n",
+				  hccs_port_type_to_name(hdev, HCCS_V2));
+
+	return -EINVAL;
+}
+static struct kobj_attribute available_inc_dec_lane_types_attr =
+		__ATTR(available_inc_dec_lane_types, 0444,
+		       available_inc_dec_lane_types_show, NULL);
 
 static ssize_t used_types_show(struct kobject *kobj,
 			       struct kobj_attribute *attr, char *buf)
@@ -1215,11 +1550,50 @@ static struct kobj_attribute used_types_attr =
 static void hccs_remove_misc_sysfs(struct hccs_dev *hdev)
 {
 	sysfs_remove_file(&hdev->dev->kobj, &used_types_attr.attr);
+
+	if (!(hdev->caps & HCCS_CAPS_HCCS_V2_PM))
+		return;
+
+	sysfs_remove_file(&hdev->dev->kobj,
+			  &available_inc_dec_lane_types_attr.attr);
+	sysfs_remove_file(&hdev->dev->kobj, &dec_lane_of_type_attr.attr);
+	sysfs_remove_file(&hdev->dev->kobj, &inc_lane_of_type_attr.attr);
 }
 
 static int hccs_add_misc_sysfs(struct hccs_dev *hdev)
 {
-	return sysfs_create_file(&hdev->dev->kobj, &used_types_attr.attr);
+	int ret;
+
+	ret = sysfs_create_file(&hdev->dev->kobj, &used_types_attr.attr);
+	if (ret)
+		return ret;
+
+	if (!(hdev->caps & HCCS_CAPS_HCCS_V2_PM))
+		return 0;
+
+	ret = sysfs_create_file(&hdev->dev->kobj,
+				&available_inc_dec_lane_types_attr.attr);
+	if (ret)
+		goto used_types_remove;
+
+	ret = sysfs_create_file(&hdev->dev->kobj, &dec_lane_of_type_attr.attr);
+	if (ret)
+		goto inc_dec_lane_types_remove;
+
+	ret = sysfs_create_file(&hdev->dev->kobj, &inc_lane_of_type_attr.attr);
+	if (ret)
+		goto dec_lane_of_type_remove;
+
+	return 0;
+
+dec_lane_of_type_remove:
+	sysfs_remove_file(&hdev->dev->kobj, &dec_lane_of_type_attr.attr);
+inc_dec_lane_types_remove:
+	sysfs_remove_file(&hdev->dev->kobj,
+			  &available_inc_dec_lane_types_attr.attr);
+used_types_remove:
+	sysfs_remove_file(&hdev->dev->kobj, &used_types_attr.attr);
+	return ret;
 }
 
 static void hccs_remove_die_dir(struct hccs_die_info *die)

drivers/soc/hisilicon/kunpeng_hccs.h

@@ -80,10 +80,13 @@ struct hccs_verspecific_data {
 	bool has_txdone_irq;
 };
 
+#define HCCS_CAPS_HCCS_V2_PM	BIT_ULL(0)
+
 struct hccs_dev {
 	struct device *dev;
 	struct acpi_device *acpi_dev;
 	const struct hccs_verspecific_data *verspec_data;
+	/* device capabilities from firmware, like HCCS_CAPS_xxx. */
 	u64 caps;
 	u8 chip_num;
 	struct hccs_chip_info *chips;
@@ -106,6 +109,9 @@ enum hccs_subcmd_type {
 	HCCS_GET_DIE_PORTS_LANE_STA,
 	HCCS_GET_DIE_PORTS_LINK_STA,
 	HCCS_GET_DIE_PORTS_CRC_ERR_CNT,
+	HCCS_GET_PORT_IDLE_STATUS,
+	HCCS_PM_DEC_LANE,
+	HCCS_PM_INC_LANE,
 	HCCS_SUB_CMD_MAX = 255,
 };
 
@@ -149,6 +155,14 @@ struct hccs_port_comm_req_param {
 	u8 port_id;
 };
 
+#define HCCS_PREPARE_INC_LANE	1
+#define HCCS_GET_ADAPT_RES	2
+#define HCCS_START_RETRAINING	3
+struct hccs_inc_lane_req_param {
+	u8 port_type;
+	u8 opt_type;
+};
+
 #define HCCS_PORT_RESET         1
 #define HCCS_PORT_SETUP         2
 #define HCCS_PORT_CONFIG        3