229 lines
7.1 KiB
C
229 lines
7.1 KiB
C
/* SPDX-License-Identifier: GPL-2.0-or-later */
|
|
/*
|
|
* internal.h - printk internal definitions
|
|
*/
|
|
#include <linux/percpu.h>
|
|
#include <linux/console.h>
|
|
#include "printk_ringbuffer.h"
|
|
|
|
#if defined(CONFIG_PRINTK) && defined(CONFIG_SYSCTL)
|
|
void __init printk_sysctl_init(void);
|
|
int devkmsg_sysctl_set_loglvl(struct ctl_table *table, int write,
|
|
void *buffer, size_t *lenp, loff_t *ppos);
|
|
#else
|
|
#define printk_sysctl_init() do { } while (0)
|
|
#endif
|
|
|
|
#define con_printk(lvl, con, fmt, ...) \
|
|
printk(lvl pr_fmt("%s%sconsole [%s%d] " fmt), \
|
|
(con->flags & CON_NBCON) ? "" : "legacy ", \
|
|
(con->flags & CON_BOOT) ? "boot" : "", \
|
|
con->name, con->index, ##__VA_ARGS__)
|
|
|
|
#ifdef CONFIG_PRINTK
|
|
|
|
#ifdef CONFIG_PRINTK_CALLER
|
|
#define PRINTK_PREFIX_MAX 48
|
|
#else
|
|
#define PRINTK_PREFIX_MAX 32
|
|
#endif
|
|
|
|
/*
|
|
* the maximum size of a formatted record (i.e. with prefix added
|
|
* per line and dropped messages or in extended message format)
|
|
*/
|
|
#define PRINTK_MESSAGE_MAX 2048
|
|
|
|
/* the maximum size allowed to be reserved for a record */
|
|
#define PRINTKRB_RECORD_MAX 1024
|
|
|
|
/* Flags for a single printk record. */
|
|
enum printk_info_flags {
|
|
LOG_NEWLINE = 2, /* text ended with a newline */
|
|
LOG_CONT = 8, /* text is a fragment of a continuation line */
|
|
};
|
|
|
|
extern struct printk_ringbuffer *prb;
|
|
extern bool printk_threads_enabled;
|
|
extern bool have_legacy_console;
|
|
extern bool have_boot_console;
|
|
|
|
/*
|
|
* Specifies if the console lock/unlock dance is needed for console
|
|
* printing. If @have_boot_console is true, the nbcon consoles will
|
|
* be printed serially along with the legacy consoles because nbcon
|
|
* consoles cannot print simultaneously with boot consoles.
|
|
*/
|
|
#define printing_via_unlock (have_legacy_console || have_boot_console)
|
|
|
|
__printf(4, 0)
|
|
int vprintk_store(int facility, int level,
|
|
const struct dev_printk_info *dev_info,
|
|
const char *fmt, va_list args);
|
|
|
|
__printf(1, 0) int vprintk_default(const char *fmt, va_list args);
|
|
__printf(1, 0) int vprintk_deferred(const char *fmt, va_list args);
|
|
|
|
bool printk_percpu_data_ready(void);
|
|
|
|
#define printk_safe_enter_irqsave(flags) \
|
|
do { \
|
|
local_irq_save(flags); \
|
|
__printk_safe_enter(); \
|
|
} while (0)
|
|
|
|
#define printk_safe_exit_irqrestore(flags) \
|
|
do { \
|
|
__printk_safe_exit(); \
|
|
local_irq_restore(flags); \
|
|
} while (0)
|
|
|
|
void defer_console_output(void);
|
|
|
|
u16 printk_parse_prefix(const char *text, int *level,
|
|
enum printk_info_flags *flags);
|
|
void console_lock_spinning_enable(void);
|
|
int console_lock_spinning_disable_and_check(int cookie);
|
|
|
|
u64 nbcon_seq_read(struct console *con);
|
|
void nbcon_seq_force(struct console *con, u64 seq);
|
|
bool nbcon_alloc(struct console *con);
|
|
void nbcon_init(struct console *con);
|
|
void nbcon_free(struct console *con);
|
|
enum nbcon_prio nbcon_get_default_prio(void);
|
|
void nbcon_atomic_flush_all(void);
|
|
bool nbcon_atomic_emit_next_record(struct console *con, bool *handover, int cookie);
|
|
void nbcon_kthread_create(struct console *con);
|
|
void nbcon_wake_threads(void);
|
|
void nbcon_legacy_kthread_create(void);
|
|
|
|
/*
|
|
* Check if the given console is currently capable and allowed to print
|
|
* records. Note that this function does not consider the current context,
|
|
* which can also play a role in deciding if @con can be used to print
|
|
* records.
|
|
*/
|
|
static inline bool console_is_usable(struct console *con, short flags, bool use_atomic)
|
|
{
|
|
if (!(flags & CON_ENABLED))
|
|
return false;
|
|
|
|
if ((flags & CON_SUSPENDED))
|
|
return false;
|
|
|
|
if (flags & CON_NBCON) {
|
|
if (use_atomic) {
|
|
if (!con->write_atomic)
|
|
return false;
|
|
} else {
|
|
if (!con->write_thread || !con->kthread)
|
|
return false;
|
|
}
|
|
} else {
|
|
if (!con->write)
|
|
return false;
|
|
}
|
|
|
|
/*
|
|
* Console drivers may assume that per-cpu resources have been
|
|
* allocated. So unless they're explicitly marked as being able to
|
|
* cope (CON_ANYTIME) don't call them until this CPU is officially up.
|
|
*/
|
|
if (!cpu_online(raw_smp_processor_id()) && !(flags & CON_ANYTIME))
|
|
return false;
|
|
|
|
return true;
|
|
}
|
|
|
|
/**
|
|
* nbcon_kthread_wake - Wake up a printk thread
|
|
* @con: Console to operate on
|
|
*/
|
|
static inline void nbcon_kthread_wake(struct console *con)
|
|
{
|
|
/*
|
|
* Guarantee any new records can be seen by tasks preparing to wait
|
|
* before this context checks if the rcuwait is empty.
|
|
*
|
|
* The full memory barrier in rcuwait_wake_up() pairs with the full
|
|
* memory barrier within set_current_state() of
|
|
* ___rcuwait_wait_event(), which is called after prepare_to_rcuwait()
|
|
* adds the waiter but before it has checked the wait condition.
|
|
*
|
|
* This pairs with nbcon_kthread_func:A.
|
|
*/
|
|
rcuwait_wake_up(&con->rcuwait); /* LMM(nbcon_kthread_wake:A) */
|
|
}
|
|
|
|
#else
|
|
|
|
#define PRINTK_PREFIX_MAX 0
|
|
#define PRINTK_MESSAGE_MAX 0
|
|
#define PRINTKRB_RECORD_MAX 0
|
|
|
|
static inline void nbcon_kthread_wake(struct console *con) { }
|
|
static inline void nbcon_kthread_create(struct console *con) { }
|
|
#define printk_threads_enabled (false)
|
|
#define printing_via_unlock (false)
|
|
|
|
/*
|
|
* In !PRINTK builds we still export console_sem
|
|
* semaphore and some of console functions (console_unlock()/etc.), so
|
|
* printk-safe must preserve the existing local IRQ guarantees.
|
|
*/
|
|
#define printk_safe_enter_irqsave(flags) local_irq_save(flags)
|
|
#define printk_safe_exit_irqrestore(flags) local_irq_restore(flags)
|
|
|
|
static inline bool printk_percpu_data_ready(void) { return false; }
|
|
static inline u64 nbcon_seq_read(struct console *con) { return 0; }
|
|
static inline void nbcon_seq_force(struct console *con, u64 seq) { }
|
|
static inline bool nbcon_alloc(struct console *con) { return false; }
|
|
static inline void nbcon_init(struct console *con) { }
|
|
static inline void nbcon_free(struct console *con) { }
|
|
static inline enum nbcon_prio nbcon_get_default_prio(void) { return NBCON_PRIO_NONE; }
|
|
static inline void nbcon_atomic_flush_all(void) { }
|
|
static inline bool nbcon_atomic_emit_next_record(struct console *con, bool *handover,
|
|
int cookie) { return false; }
|
|
|
|
static inline bool console_is_usable(struct console *con, short flags,
|
|
bool use_atomic) { return false; }
|
|
|
|
#endif /* CONFIG_PRINTK */
|
|
|
|
extern struct printk_buffers printk_shared_pbufs;
|
|
|
|
/**
|
|
* struct printk_buffers - Buffers to read/format/output printk messages.
|
|
* @outbuf: After formatting, contains text to output.
|
|
* @scratchbuf: Used as temporary ringbuffer reading and string-print space.
|
|
*/
|
|
struct printk_buffers {
|
|
char outbuf[PRINTK_MESSAGE_MAX];
|
|
char scratchbuf[PRINTKRB_RECORD_MAX];
|
|
};
|
|
|
|
/**
|
|
* struct printk_message - Container for a prepared printk message.
|
|
* @pbufs: printk buffers used to prepare the message.
|
|
* @outbuf_len: The length of prepared text in @pbufs->outbuf to output. This
|
|
* does not count the terminator. A value of 0 means there is
|
|
* nothing to output and this record should be skipped.
|
|
* @seq: The sequence number of the record used for @pbufs->outbuf.
|
|
* @dropped: The number of dropped records from reading @seq.
|
|
*/
|
|
struct printk_message {
|
|
struct printk_buffers *pbufs;
|
|
unsigned int outbuf_len;
|
|
u64 seq;
|
|
unsigned long dropped;
|
|
};
|
|
|
|
bool other_cpu_in_panic(void);
|
|
bool this_cpu_in_panic(void);
|
|
bool printk_get_next_message(struct printk_message *pmsg, u64 seq,
|
|
bool is_extended, bool may_supress);
|
|
|
|
#ifdef CONFIG_PRINTK
|
|
void console_prepend_dropped(struct printk_message *pmsg, unsigned long dropped);
|
|
#endif
|