diff options
Diffstat (limited to 'include/linux/serial_core.h')
| -rw-r--r-- | include/linux/serial_core.h | 221 |
1 files changed, 185 insertions, 36 deletions
diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h index 0a0f6e21d40e..914b5e97e056 100644 --- a/include/linux/serial_core.h +++ b/include/linux/serial_core.h @@ -11,7 +11,8 @@ #include <linux/compiler.h> #include <linux/console.h> #include <linux/interrupt.h> -#include <linux/circ_buf.h> +#include <linux/lockdep.h> +#include <linux/printk.h> #include <linux/spinlock.h> #include <linux/sched.h> #include <linux/tty.h> @@ -426,6 +427,18 @@ struct uart_icount { typedef u64 __bitwise upf_t; typedef unsigned int __bitwise upstat_t; +enum uart_iotype { + UPIO_UNKNOWN = -1, + UPIO_PORT = SERIAL_IO_PORT, /* 8b I/O port access */ + UPIO_HUB6 = SERIAL_IO_HUB6, /* Hub6 ISA card */ + UPIO_MEM = SERIAL_IO_MEM, /* driver-specific */ + UPIO_MEM32 = SERIAL_IO_MEM32, /* 32b little endian */ + UPIO_AU = SERIAL_IO_AU, /* Au1x00 and RT288x type IO */ + UPIO_TSI = SERIAL_IO_TSI, /* Tsi108/109 type IO */ + UPIO_MEM32BE = SERIAL_IO_MEM32BE, /* 32b big endian */ + UPIO_MEM16 = SERIAL_IO_MEM16, /* 16b little endian */ +}; + struct uart_port { spinlock_t lock; /* port lock */ unsigned long iobase; /* in/out[bwl] */ @@ -468,23 +481,13 @@ struct uart_port { unsigned char x_char; /* xon/xoff char */ unsigned char regshift; /* reg offset shift */ - unsigned char iotype; /* io access style */ - -#define UPIO_UNKNOWN ((unsigned char)~0U) /* UCHAR_MAX */ -#define UPIO_PORT (SERIAL_IO_PORT) /* 8b I/O port access */ -#define UPIO_HUB6 (SERIAL_IO_HUB6) /* Hub6 ISA card */ -#define UPIO_MEM (SERIAL_IO_MEM) /* driver-specific */ -#define UPIO_MEM32 (SERIAL_IO_MEM32) /* 32b little endian */ -#define UPIO_AU (SERIAL_IO_AU) /* Au1x00 and RT288x type IO */ -#define UPIO_TSI (SERIAL_IO_TSI) /* Tsi108/109 type IO */ -#define UPIO_MEM32BE (SERIAL_IO_MEM32BE) /* 32b big endian */ -#define UPIO_MEM16 (SERIAL_IO_MEM16) /* 16b little endian */ - unsigned char quirks; /* internal quirks */ /* internal quirks must be updated while holding port mutex */ #define UPQ_NO_TXEN_TEST BIT(0) + enum uart_iotype iotype; /* io access style */ + unsigned int read_status_mask; /* driver specific */ unsigned int ignore_status_mask; /* driver specific */ struct uart_state *state; /* pointer to parent state */ @@ -504,7 +507,11 @@ struct uart_port { * The remaining bits are serial-core specific and not modifiable by * userspace. */ +#ifdef CONFIG_HAS_IOPORT #define UPF_FOURPORT ((__force upf_t) ASYNC_FOURPORT /* 1 */ ) +#else +#define UPF_FOURPORT 0 +#endif #define UPF_SAK ((__force upf_t) ASYNC_SAK /* 2 */ ) #define UPF_SPD_HI ((__force upf_t) ASYNC_SPD_HI /* 4 */ ) #define UPF_SPD_VHI ((__force upf_t) ASYNC_SPD_VHI /* 5 */ ) @@ -591,6 +598,95 @@ struct uart_port { void *private_data; /* generic platform data pointer */ }; +/* + * Only for console->device_lock()/_unlock() callbacks and internal + * port lock wrapper synchronization. + */ +static inline void __uart_port_lock_irqsave(struct uart_port *up, unsigned long *flags) +{ + spin_lock_irqsave(&up->lock, *flags); +} + +/* + * Only for console->device_lock()/_unlock() callbacks and internal + * port lock wrapper synchronization. + */ +static inline void __uart_port_unlock_irqrestore(struct uart_port *up, unsigned long flags) +{ + spin_unlock_irqrestore(&up->lock, flags); +} + +/** + * uart_port_set_cons - Safely set the @cons field for a uart + * @up: The uart port to set + * @con: The new console to set to + * + * This function must be used to set @up->cons. It uses the port lock to + * synchronize with the port lock wrappers in order to ensure that the console + * cannot change or disappear while another context is holding the port lock. + */ +static inline void uart_port_set_cons(struct uart_port *up, struct console *con) +{ + unsigned long flags; + + __uart_port_lock_irqsave(up, &flags); + up->cons = con; + __uart_port_unlock_irqrestore(up, flags); +} + +/* Only for internal port lock wrapper usage. */ +static inline bool __uart_port_using_nbcon(struct uart_port *up) +{ + lockdep_assert_held_once(&up->lock); + + if (likely(!uart_console(up))) + return false; + + /* + * @up->cons is only modified under the port lock. Therefore it is + * certain that it cannot disappear here. + * + * @up->cons->node is added/removed from the console list under the + * port lock. Therefore it is certain that the registration status + * cannot change here, thus @up->cons->flags can be read directly. + */ + if (hlist_unhashed_lockless(&up->cons->node) || + !(up->cons->flags & CON_NBCON) || + !up->cons->write_atomic) { + return false; + } + + return true; +} + +/* Only for internal port lock wrapper usage. */ +static inline bool __uart_port_nbcon_try_acquire(struct uart_port *up) +{ + if (!__uart_port_using_nbcon(up)) + return true; + + return nbcon_device_try_acquire(up->cons); +} + +/* Only for internal port lock wrapper usage. */ +static inline void __uart_port_nbcon_acquire(struct uart_port *up) +{ + if (!__uart_port_using_nbcon(up)) + return; + + while (!nbcon_device_try_acquire(up->cons)) + cpu_relax(); +} + +/* Only for internal port lock wrapper usage. */ +static inline void __uart_port_nbcon_release(struct uart_port *up) +{ + if (!__uart_port_using_nbcon(up)) + return; + + nbcon_device_release(up->cons); +} + /** * uart_port_lock - Lock the UART port * @up: Pointer to UART port structure @@ -598,6 +694,7 @@ struct uart_port { static inline void uart_port_lock(struct uart_port *up) { spin_lock(&up->lock); + __uart_port_nbcon_acquire(up); } /** @@ -607,6 +704,7 @@ static inline void uart_port_lock(struct uart_port *up) static inline void uart_port_lock_irq(struct uart_port *up) { spin_lock_irq(&up->lock); + __uart_port_nbcon_acquire(up); } /** @@ -617,6 +715,7 @@ static inline void uart_port_lock_irq(struct uart_port *up) static inline void uart_port_lock_irqsave(struct uart_port *up, unsigned long *flags) { spin_lock_irqsave(&up->lock, *flags); + __uart_port_nbcon_acquire(up); } /** @@ -627,7 +726,15 @@ static inline void uart_port_lock_irqsave(struct uart_port *up, unsigned long *f */ static inline bool uart_port_trylock(struct uart_port *up) { - return spin_trylock(&up->lock); + if (!spin_trylock(&up->lock)) + return false; + + if (!__uart_port_nbcon_try_acquire(up)) { + spin_unlock(&up->lock); + return false; + } + + return true; } /** @@ -639,7 +746,15 @@ static inline bool uart_port_trylock(struct uart_port *up) */ static inline bool uart_port_trylock_irqsave(struct uart_port *up, unsigned long *flags) { - return spin_trylock_irqsave(&up->lock, *flags); + if (!spin_trylock_irqsave(&up->lock, *flags)) + return false; + + if (!__uart_port_nbcon_try_acquire(up)) { + spin_unlock_irqrestore(&up->lock, *flags); + return false; + } + + return true; } /** @@ -648,6 +763,7 @@ static inline bool uart_port_trylock_irqsave(struct uart_port *up, unsigned long */ static inline void uart_port_unlock(struct uart_port *up) { + __uart_port_nbcon_release(up); spin_unlock(&up->lock); } @@ -657,6 +773,7 @@ static inline void uart_port_unlock(struct uart_port *up) */ static inline void uart_port_unlock_irq(struct uart_port *up) { + __uart_port_nbcon_release(up); spin_unlock_irq(&up->lock); } @@ -667,6 +784,7 @@ static inline void uart_port_unlock_irq(struct uart_port *up) */ static inline void uart_port_unlock_irqrestore(struct uart_port *up, unsigned long flags) { + __uart_port_nbcon_release(up); spin_unlock_irqrestore(&up->lock, flags); } @@ -699,7 +817,6 @@ struct uart_state { struct tty_port port; enum uart_pm_state pm_state; - struct circ_buf xmit; atomic_t refcount; wait_queue_head_t remove_wait; @@ -723,12 +840,35 @@ struct uart_state { */ static inline void uart_xmit_advance(struct uart_port *up, unsigned int chars) { - struct circ_buf *xmit = &up->state->xmit; + struct tty_port *tport = &up->state->port; - xmit->tail = (xmit->tail + chars) & (UART_XMIT_SIZE - 1); + kfifo_skip_count(&tport->xmit_fifo, chars); up->icount.tx += chars; } +static inline unsigned int uart_fifo_out(struct uart_port *up, + unsigned char *buf, unsigned int chars) +{ + struct tty_port *tport = &up->state->port; + + chars = kfifo_out(&tport->xmit_fifo, buf, chars); + up->icount.tx += chars; + + return chars; +} + +static inline unsigned int uart_fifo_get(struct uart_port *up, + unsigned char *ch) +{ + struct tty_port *tport = &up->state->port; + unsigned int chars; + + chars = kfifo_get(&tport->xmit_fifo, ch); + up->icount.tx += chars; + + return chars; +} + struct module; struct tty_driver; @@ -764,7 +904,7 @@ enum UART_TX_FLAGS { for_test, for_post) \ ({ \ struct uart_port *__port = (uport); \ - struct circ_buf *xmit = &__port->state->xmit; \ + struct tty_port *__tport = &__port->state->port; \ unsigned int pending; \ \ for (; (for_test) && (tx_ready); (for_post), __port->icount.tx++) { \ @@ -775,22 +915,22 @@ enum UART_TX_FLAGS { continue; \ } \ \ - if (uart_circ_empty(xmit) || uart_tx_stopped(__port)) \ + if (uart_tx_stopped(__port)) \ + break; \ + \ + if (!kfifo_get(&__tport->xmit_fifo, &(ch))) \ break; \ \ - (ch) = xmit->buf[xmit->tail]; \ (put_char); \ - xmit->tail = (xmit->tail + 1) % UART_XMIT_SIZE; \ } \ \ (tx_done); \ \ - pending = uart_circ_chars_pending(xmit); \ + pending = kfifo_len(&__tport->xmit_fifo); \ if (pending < WAKEUP_CHARS) { \ uart_write_wakeup(__port); \ \ - if (!((flags) & UART_TX_NOSTOP) && pending == 0 && \ - __port->ops->tx_empty(__port)) \ + if (!((flags) & UART_TX_NOSTOP) && pending == 0) \ __port->ops->stop_tx(__port); \ } \ \ @@ -830,6 +970,24 @@ enum UART_TX_FLAGS { }) /** + * uart_port_tx_limited_flags -- transmit helper for uart_port with count limiting with flags + * @port: uart port + * @ch: variable to store a character to be written to the HW + * @flags: %UART_TX_NOSTOP or similar + * @count: a limit of characters to send + * @tx_ready: can HW accept more data function + * @put_char: function to write a character + * @tx_done: function to call after the loop is done + * + * See uart_port_tx_limited() for more details. + */ +#define uart_port_tx_limited_flags(port, ch, flags, count, tx_ready, put_char, tx_done) ({ \ + unsigned int __count = (count); \ + __uart_port_tx(port, ch, flags, tx_ready, put_char, tx_done, __count, \ + __count--); \ +}) + +/** * uart_port_tx -- transmit helper for uart_port * @port: uart port * @ch: variable to store a character to be written to the HW @@ -945,8 +1103,8 @@ static inline bool uart_console_registered(struct uart_port *port) struct uart_port *uart_get_console(struct uart_port *ports, int nr, struct console *c); -int uart_parse_earlycon(char *p, unsigned char *iotype, resource_size_t *addr, - char **options); +int uart_parse_earlycon(char *p, enum uart_iotype *iotype, + resource_size_t *addr, char **options); void uart_parse_options(const char *options, int *baud, int *parity, int *bits, int *flow); int uart_set_options(struct uart_port *port, struct console *co, int baud, @@ -974,15 +1132,6 @@ bool uart_match_port(const struct uart_port *port1, int uart_suspend_port(struct uart_driver *reg, struct uart_port *port); int uart_resume_port(struct uart_driver *reg, struct uart_port *port); -#define uart_circ_empty(circ) ((circ)->head == (circ)->tail) -#define uart_circ_clear(circ) ((circ)->head = (circ)->tail = 0) - -#define uart_circ_chars_pending(circ) \ - (CIRC_CNT((circ)->head, (circ)->tail, UART_XMIT_SIZE)) - -#define uart_circ_chars_free(circ) \ - (CIRC_SPACE((circ)->head, (circ)->tail, UART_XMIT_SIZE)) - static inline int uart_tx_stopped(struct uart_port *port) { struct tty_struct *tty = port->state->port.tty; 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