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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290/* SPDX-License-Identifier: GPL-2.0-only *//* * Persistent Storage - pstore.h * * Copyright (C) 2010 Intel Corporation <tony.luck@intel.com> * * This code is the generic layer to export data records from platform * level persistent storage via a file system. */#ifndef _LINUX_PSTORE_H#define _LINUX_PSTORE_H
#include <linux/compiler.h>#include <linux/errno.h>#include <linux/kmsg_dump.h>#include <linux/mutex.h>#include <linux/spinlock.h>#include <linux/time.h>#include <linux/types.h>
struct module;
/* * pstore record types (see fs/pstore/platform.c for pstore_type_names[]) * These values may be written to storage (see EFI vars backend), so * they are kind of an ABI. Be careful changing the mappings. */enum pstore_type_id { /* Frontend storage types */ PSTORE_TYPE_DMESG = 0, PSTORE_TYPE_MCE = 1, PSTORE_TYPE_CONSOLE = 2, PSTORE_TYPE_FTRACE = 3,
/* PPC64-specific partition types */ PSTORE_TYPE_PPC_RTAS = 4, PSTORE_TYPE_PPC_OF = 5, PSTORE_TYPE_PPC_COMMON = 6, PSTORE_TYPE_PMSG = 7, PSTORE_TYPE_PPC_OPAL = 8,
/* End of the list */ PSTORE_TYPE_MAX};
const char *pstore_type_to_name(enum pstore_type_id type);enum pstore_type_id pstore_name_to_type(const char *name);
struct pstore_info;/** * struct pstore_record - details of a pstore record entry * @psi: pstore backend driver information * @type: pstore record type * @id: per-type unique identifier for record * @time: timestamp of the record * @buf: pointer to record contents * @size: size of @buf * @ecc_notice_size: * ECC information for @buf * @priv: pointer for backend specific use, will be * kfree()d by the pstore core if non-NULL * when the record is freed. * * Valid for PSTORE_TYPE_DMESG @type: * * @count: Oops count since boot * @reason: kdump reason for notification * @part: position in a multipart record * @compressed: whether the buffer is compressed * */struct pstore_record { struct pstore_info *psi; enum pstore_type_id type; u64 id; struct timespec64 time; char *buf; ssize_t size; ssize_t ecc_notice_size; void *priv;
int count; enum kmsg_dump_reason reason; unsigned int part; bool compressed;};
/** * struct pstore_info - backend pstore driver structure * * @owner: module which is responsible for this backend driver * @name: name of the backend driver * * @buf_lock: spinlock to serialize access to @buf * @buf: preallocated crash dump buffer * @bufsize: size of @buf available for crash dump bytes (must match * smallest number of bytes available for writing to a * backend entry, since compressed bytes don't take kindly * to being truncated) * * @read_mutex: serializes @open, @read, @close, and @erase callbacks * @flags: bitfield of frontends the backend can accept writes for * @max_reason: Used when PSTORE_FLAGS_DMESG is set. Contains the * kmsg_dump_reason enum value. KMSG_DUMP_UNDEF means * "use existing kmsg_dump() filtering, based on the * printk.always_kmsg_dump boot param" (which is either * KMSG_DUMP_OOPS when false, or KMSG_DUMP_MAX when * true); see printk.always_kmsg_dump for more details. * @data: backend-private pointer passed back during callbacks * * Callbacks: * * @open: * Notify backend that pstore is starting a full read of backend * records. Followed by one or more @read calls, and a final @close. * * @psi: in: pointer to the struct pstore_info for the backend * * Returns 0 on success, and non-zero on error. * * @close: * Notify backend that pstore has finished a full read of backend * records. Always preceded by an @open call and one or more @read * calls. * * @psi: in: pointer to the struct pstore_info for the backend * * Returns 0 on success, and non-zero on error. (Though pstore will * ignore the error.) * * @read: * Read next available backend record. Called after a successful * @open. * * @record: * pointer to record to populate. @buf should be allocated * by the backend and filled. At least @type and @id should * be populated, since these are used when creating pstorefs * file names. * * Returns record size on success, zero when no more records are * available, or negative on error. * * @write: * A newly generated record needs to be written to backend storage. * * @record: * pointer to record metadata. When @type is PSTORE_TYPE_DMESG, * @buf will be pointing to the preallocated @psi.buf, since * memory allocation may be broken during an Oops. Regardless, * @buf must be proccesed or copied before returning. The * backend is also expected to write @id with something that * can help identify this record to a future @erase callback. * The @time field will be prepopulated with the current time, * when available. The @size field will have the size of data * in @buf. * * Returns 0 on success, and non-zero on error. * * @write_user: * Perform a frontend write to a backend record, using a specified * buffer that is coming directly from userspace, instead of the * @record @buf. * * @record: pointer to record metadata. * @buf: pointer to userspace contents to write to backend * * Returns 0 on success, and non-zero on error. * * @erase: * Delete a record from backend storage. Different backends * identify records differently, so entire original record is * passed back to assist in identification of what the backend * should remove from storage. * * @record: pointer to record metadata. * * Returns 0 on success, and non-zero on error. * */struct pstore_info { struct module *owner; const char *name;
raw_spinlock_t buf_lock; char *buf; size_t bufsize;
struct mutex read_mutex;
int flags; int max_reason; void *data;
int (*open)(struct pstore_info *psi); int (*close)(struct pstore_info *psi); ssize_t (*read)(struct pstore_record *record); int (*write)(struct pstore_record *record); int (*write_user)(struct pstore_record *record, const char __user *buf); int (*erase)(struct pstore_record *record);};
/* Supported frontends */#define PSTORE_FLAGS_DMESG BIT(0)#define PSTORE_FLAGS_CONSOLE BIT(1)#define PSTORE_FLAGS_FTRACE BIT(2)#define PSTORE_FLAGS_PMSG BIT(3)
extern int pstore_register(struct pstore_info *);extern void pstore_unregister(struct pstore_info *);
struct pstore_ftrace_record { unsigned long ip; unsigned long parent_ip; u64 ts;};
/* * ftrace related stuff: Both backends and frontends need these so expose * them here. */
#if NR_CPUS <= 2 && defined(CONFIG_ARM_THUMB)#define PSTORE_CPU_IN_IP 0x1#elif NR_CPUS <= 4 && defined(CONFIG_ARM)#define PSTORE_CPU_IN_IP 0x3#endif
#define TS_CPU_SHIFT 8#define TS_CPU_MASK (BIT(TS_CPU_SHIFT) - 1)
/* * If CPU number can be stored in IP, store it there, otherwise store it in * the time stamp. This means more timestamp resolution is available when * the CPU can be stored in the IP. */#ifdef PSTORE_CPU_IN_IPstatic inline voidpstore_ftrace_encode_cpu(struct pstore_ftrace_record *rec, unsigned int cpu){ rec->ip |= cpu;}
static inline unsigned intpstore_ftrace_decode_cpu(struct pstore_ftrace_record *rec){ return rec->ip & PSTORE_CPU_IN_IP;}
static inline u64pstore_ftrace_read_timestamp(struct pstore_ftrace_record *rec){ return rec->ts;}
static inline voidpstore_ftrace_write_timestamp(struct pstore_ftrace_record *rec, u64 val){ rec->ts = val;}#elsestatic inline voidpstore_ftrace_encode_cpu(struct pstore_ftrace_record *rec, unsigned int cpu){ rec->ts &= ~(TS_CPU_MASK); rec->ts |= cpu;}
static inline unsigned intpstore_ftrace_decode_cpu(struct pstore_ftrace_record *rec){ return rec->ts & TS_CPU_MASK;}
static inline u64pstore_ftrace_read_timestamp(struct pstore_ftrace_record *rec){ return rec->ts >> TS_CPU_SHIFT;}
static inline voidpstore_ftrace_write_timestamp(struct pstore_ftrace_record *rec, u64 val){ rec->ts = (rec->ts & TS_CPU_MASK) | (val << TS_CPU_SHIFT);}#endif
#endif /*_LINUX_PSTORE_H*/