soc: hbmcache: Add support for online and offline the hbm cache

hulk inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I6I7DH
CVE: NA

--------------------------------------------------

Add a driver for hbm cache, which support for power on/off the
hbm cache device. Hbm can be used as a cache, for which a normal
memory access can take advantage of the high band width of hbm.
Signed-off-by: NZhang Zekun <zhangzekun11@huawei.com>
Reviewed-by: NKefeng Wang <wangkefeng.wang@huawei.com>

drivers/soc/hisilicon/Kconfig

@@ -19,4 +19,15 @@ config HISI_HBMDEV
 	  To compile this driver as a module, choose M here:
 	  the module will be called hisi_hbmdev.
 
+config HISI_HBMCACHE
+	tristate "HBM cache memory device"
+	depends on ACPI
+	help
+	  This driver provids methods to control the power of hbm cache device
+	  in hisi soc. Use hbm as a cache can take advantage of hbm's high
+	  bandwidth in normal memory access.
+
+	  To compile the driver as a module, choose M here:
+	  the module will be called hisi_hbmcache.
+
 endmenu

drivers/soc/hisilicon/Makefile

 # SPDX-License-Identifier: GPL-2.0
 
 obj-$(CONFIG_HISI_HBMDEV)	+= hisi_hbmdev.o
+obj-$(CONFIG_HISI_HBMCACHE)	+= hisi_hbmcache.o

drivers/soc/hisilicon/hisi_hbmcache.c

+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) Huawei Technologies Co., Ltd. 2023. All rights reserved.
+ */
+
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/acpi.h>
+#include <linux/device.h>
+
+#include "hisi_internal.h"
+
+#define MODULE_NAME            "hbm_cache"
+
+static struct kobject *cache_kobj;
+
+static ssize_t state_store(struct device *d, struct device_attribute *attr,
+			   const char *buf, size_t count)
+{
+	struct acpi_device *adev = ACPI_COMPANION(d);
+	const int type = online_type_from_str(buf);
+	int ret = -EINVAL;
+
+	switch (type) {
+	case STATE_ONLINE:
+		ret = acpi_device_set_power(adev, ACPI_STATE_D0);
+		break;
+	case STATE_OFFLINE:
+		ret = acpi_device_set_power(adev, ACPI_STATE_D3);
+		break;
+	default:
+		break;
+	}
+
+	if (ret)
+		return ret;
+
+	return count;
+}
+
+static ssize_t state_show(struct device *d, struct device_attribute *attr,
+			  char *buf)
+{
+	struct acpi_device *adev = ACPI_COMPANION(d);
+	unsigned long long sta = 0;
+	acpi_status status;
+	const char *output;
+
+	status = acpi_evaluate_integer(adev->handle, "_STA", NULL, &sta);
+	if (ACPI_FAILURE(status))
+		return -EINVAL;
+
+	output = (sta & 0x01) ? online_type_to_str[STATE_ONLINE] :
+				online_type_to_str[STATE_OFFLINE];
+
+	return sysfs_emit(buf, "%s\n", output);
+}
+static DEVICE_ATTR_RW(state);
+
+static ssize_t socket_id_show(struct device *d, struct device_attribute *attr,
+				char *buf)
+{
+	int socket_id;
+
+	if (device_property_read_u32(d, "socket_id", &socket_id))
+		return -EINVAL;
+
+	return sysfs_emit(buf, "%d\n", socket_id);
+}
+static DEVICE_ATTR_RO(socket_id);
+
+static struct attribute *attrs[] = {
+	&dev_attr_state.attr,
+	&dev_attr_socket_id.attr,
+	NULL,
+};
+
+static struct attribute_group attr_group = {
+	.attrs = attrs,
+};
+
+static int cache_probe(struct platform_device *pdev)
+{
+	int ret;
+
+	ret = sysfs_create_group(&pdev->dev.kobj, &attr_group);
+	if (ret)
+		return ret;
+
+	ret = sysfs_create_link(cache_kobj,
+				&pdev->dev.kobj,
+				kobject_name(&pdev->dev.kobj));
+	if (ret) {
+		sysfs_remove_group(&pdev->dev.kobj, &attr_group);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int cache_remove(struct platform_device *pdev)
+{
+	sysfs_remove_group(&pdev->dev.kobj, &attr_group);
+	sysfs_remove_link(&pdev->dev.kobj,
+			  kobject_name(&pdev->dev.kobj));
+	return 0;
+}
+
+static const struct acpi_device_id cache_acpi_ids[] = {
+	{"HISI04A1"},
+	{},
+};
+
+static struct platform_driver hbm_cache_driver = {
+	.probe = cache_probe,
+	.remove = cache_remove,
+	.driver = {
+		.name = MODULE_NAME,
+		.acpi_match_table = ACPI_PTR(cache_acpi_ids),
+	},
+};
+
+static int __init hbm_cache_module_init(void)
+{
+	int ret;
+
+	cache_kobj = kobject_create_and_add("hbm_cache", kernel_kobj);
+	if (!cache_kobj)
+		return -ENOMEM;
+
+	ret = platform_driver_register(&hbm_cache_driver);
+	if (ret) {
+		kobject_put(cache_kobj);
+		return ret;
+	}
+	return 0;
+}
+module_init(hbm_cache_module_init);
+
+static void __exit hbm_cache_module_exit(void)
+{
+	kobject_put(cache_kobj);
+	platform_driver_unregister(&hbm_cache_driver);
+}
+module_exit(hbm_cache_module_exit);
+MODULE_LICENSE("GPL");