diff options
| author | John Ogness <john.ogness@linutronix.de> | 2020-11-30 03:36:02 +0300 |
|---|---|---|
| committer | Minda Chen <minda.chen@starfivetech.com> | 2023-11-06 14:24:37 +0300 |
| commit | e87d635bbace7e3d37cae016a34cef8f490ed4ef (patch) | |
| tree | 61f300bee0a14c08bbb5e902d127f93365ea27a6 /include | |
| parent | d485610e22d3db1cbd9c0391043a8fcfdbc3f945 (diff) | |
| download | linux-e87d635bbace7e3d37cae016a34cef8f490ed4ef.tar.xz | |
serial: 8250: implement write_atomic
Implement a non-sleeping NMI-safe write_atomic() console function in
order to support emergency console printing.
Since interrupts need to be disabled during transmit, all usage of
the IER register is wrapped with access functions that use the
console_atomic_lock() function to synchronize register access while
tracking the state of the interrupts. This is necessary because
write_atomic() can be called from an NMI context that has preempted
write_atomic().
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/serial_8250.h | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/include/linux/serial_8250.h b/include/linux/serial_8250.h index 068ba67788bc..7cd20b5def9d 100644 --- a/include/linux/serial_8250.h +++ b/include/linux/serial_8250.h @@ -7,6 +7,7 @@ #ifndef _LINUX_SERIAL_8250_H #define _LINUX_SERIAL_8250_H +#include <linux/atomic.h> #include <linux/serial_core.h> #include <linux/serial_reg.h> #include <linux/platform_device.h> @@ -126,6 +127,8 @@ struct uart_8250_port { #define MSR_SAVE_FLAGS UART_MSR_ANY_DELTA unsigned char msr_saved_flags; + atomic_t console_printing; + struct uart_8250_dma *dma; const struct uart_8250_ops *ops; @@ -181,6 +184,8 @@ void serial8250_init_port(struct uart_8250_port *up); void serial8250_set_defaults(struct uart_8250_port *up); void serial8250_console_write(struct uart_8250_port *up, const char *s, unsigned int count); +void serial8250_console_write_atomic(struct uart_8250_port *up, const char *s, + unsigned int count); int serial8250_console_setup(struct uart_port *port, char *options, bool probe); int serial8250_console_exit(struct uart_port *port); |