resctrlfs: init support resctrlfs

hulk inclusion
category: feature
feature: ARM MPAM support
bugzilla: 48265
CVE: NA

--------------------------------
Signed-off-by: NXie XiuQi <xiexiuqi@huawei.com>
Reviewed-by: NHanjun Guo <guohanjun@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>
Signed-off-by: NWang ShaoBo <bobo.shaobowang@huawei.com>
Reviewed-by: NCheng Jian <cj.chengjian@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

fs/Makefile

@@ -134,6 +134,7 @@ obj-$(CONFIG_F2FS_FS)		+= f2fs/
 obj-$(CONFIG_CEPH_FS)		+= ceph/
 obj-$(CONFIG_PSTORE)		+= pstore/
 obj-$(CONFIG_EFIVAR_FS)		+= efivarfs/
+obj-$(CONFIG_RESCTRL)		+= resctrlfs.o
 obj-$(CONFIG_EROFS_FS)		+= erofs/
 obj-$(CONFIG_VBOXSF_FS)		+= vboxsf/
 obj-$(CONFIG_ZONEFS_FS)		+= zonefs/

include/linux/resctrlfs.h

+#ifndef _RESCTRLFS_H
+#define _RESCTRLFS_H
+
+#include <linux/sched.h>
+#include <linux/kernfs.h>
+#include <linux/fs_context.h>
+#include <linux/jump_label.h>
+
+#include <linux/seq_buf.h>
+#include <linux/seq_file.h>
+
+struct resctrl_resource {
+	int			rid;
+	bool			alloc_enabled;
+	bool			mon_enabled;
+	bool			alloc_capable;
+	bool			mon_capable;
+	char			*name;
+	struct list_head	domains;
+	struct list_head	evt_list;
+	unsigned long		fflags;
+
+	void *res;
+};
+
+DECLARE_STATIC_KEY_FALSE(resctrl_enable_key);
+
+/* rftype.flags */
+#define RFTYPE_FLAGS_CPUS_LIST	1
+
+/*
+ * Define the file type flags for base and info directories.
+ */
+#define RFTYPE_INFO			BIT(0)
+#define RFTYPE_BASE			BIT(1)
+#define RF_CTRLSHIFT			4
+#define RF_MONSHIFT			5
+#define RF_TOPSHIFT			6
+#define RFTYPE_CTRL			BIT(RF_CTRLSHIFT)
+#define RFTYPE_MON			BIT(RF_MONSHIFT)
+#define RFTYPE_TOP			BIT(RF_TOPSHIFT)
+#define RFTYPE_RES_SMMU			BIT(7)
+#define RFTYPE_RES_CACHE		BIT(8)
+#define RFTYPE_RES_MB			BIT(9)
+#define RFTYPE_RES_MC			BIT(10)
+#define RF_CTRL_INFO			(RFTYPE_INFO | RFTYPE_CTRL)
+#define RF_MON_INFO			(RFTYPE_INFO | RFTYPE_MON)
+#define RF_TOP_INFO			(RFTYPE_INFO | RFTYPE_TOP)
+#define RF_CTRL_BASE			(RFTYPE_BASE | RFTYPE_CTRL)
+
+/* List of all resource groups */
+extern struct list_head resctrl_all_groups;
+
+/**
+ * struct rftype - describe each file in the resctrl file system
+ * @name:	File name
+ * @mode:	Access mode
+ * @kf_ops:	File operations
+ * @flags:	File specific RFTYPE_FLAGS_* flags
+ * @fflags:	File specific RF_* or RFTYPE_* flags
+ * @seq_show:	Show content of the file
+ * @write:	Write to the file
+ */
+struct rftype {
+	char			*name;
+	umode_t			mode;
+	struct kernfs_ops	*kf_ops;
+	unsigned long		flags;
+	unsigned long		fflags;
+
+	bool (*enable)(void *arg);
+
+	int (*seq_show)(struct kernfs_open_file *of,
+			struct seq_file *sf, void *v);
+	/*
+	 * write() is the generic write callback which maps directly to
+	 * kernfs write operation and overrides all other operations.
+	 * Maximum write size is determined by ->max_write_len.
+	 */
+	ssize_t (*write)(struct kernfs_open_file *of,
+			 char *buf, size_t nbytes, loff_t off);
+};
+
+DECLARE_STATIC_KEY_FALSE(resctrl_alloc_enable_key);
+extern struct rdtgroup resctrl_group_default;
+
+int __init resctrl_group_init(void);
+
+int register_resctrl_specific_files(struct rftype *files, size_t len);
+extern struct kernfs_ops resctrl_group_kf_single_ops;
+
+extern struct rdtgroup *resctrl_group_kn_lock_live(struct kernfs_node *kn);
+void resctrl_group_kn_unlock(struct kernfs_node *kn);
+
+struct resctrl_fs_context {
+	struct kernfs_fs_context        kfc;
+};
+
+static inline struct resctrl_fs_context *resctrl_fc2context(struct fs_context *fc)
+{
+	struct kernfs_fs_context *kfc = fc->fs_private;
+
+	return container_of(kfc, struct resctrl_fs_context, kfc);
+}
+
+void post_resctrl_mount(void);
+
+#endif /* _RESCTRLFS_H */