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serial_core: Un-ifdef sysrq SUPPORT_SYSRQ 

The SUPPORT_SYSRQ is messy: every .c source should define it before
including "serial_core.h" if sysrq is supported or struct uart_port will
differ in sizes. Also this prevents moving to serial_core.c functions:
uart_handle_sysrq_char(), uart_prepare_sysrq_char(),
uart_unlock_and_check_sysrq().

It doesn't save many bytes in the structure, and a better way to reduce
it's size would be making rs485 and iso7816 pointers.

Introduce `has_sysrq` member to be used by serial line drivers further.

Signed-off-by: Dmitry Safonov <dima@arista.com>
Link: https://lore.kernel.org/r/20191213000657.931618-4-dima@arista.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Dmitry Safonov 2019-12-13 00:06:02 +00:00 committed by Greg Kroah-Hartman
parent 8336240ebb
commit 1997e9dfdc
1 changed files with 43 additions and 34 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

77
include/linux/serial_core.h
View File

@ -240,14 +240,13 @@ struct uart_port {
resource_size_t mapsize;
struct device *dev; /* parent device */
#if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(SUPPORT_SYSRQ)
unsigned long sysrq; /* sysrq timeout */
unsigned int sysrq_ch; /* char for sysrq */
#endif
unsigned char has_sysrq;
unsigned char hub6; /* this should be in the 8250 driver */
unsigned char suspended;
unsigned char unused[2];
unsigned char unused;
const char *name; /* port name */
struct attribute_group *attr_group; /* port specific attributes */
const struct attribute_group **tty_groups; /* all attributes (serial core use only) */
@ -461,31 +460,46 @@ extern void uart_handle_cts_change(struct uart_port *uport,
extern void uart_insert_char(struct uart_port *port, unsigned int status,
unsigned int overrun, unsigned int ch, unsigned int flag);
#if defined(SUPPORT_SYSRQ) && defined(CONFIG_MAGIC_SYSRQ_SERIAL)
static inline int
uart_handle_sysrq_char(struct uart_port *port, unsigned int ch)
{
if (port->sysrq) {
if (ch && time_before(jiffies, port->sysrq)) {
handle_sysrq(ch);
port->sysrq = 0;
return 1;
}
if (!IS_ENABLED(CONFIG_MAGIC_SYSRQ_SERIAL))
return 0;
if (!port->has_sysrq && !IS_ENABLED(SUPPORT_SYSRQ))
return 0;
if (!port->sysrq)
return 0;
if (ch && time_before(jiffies, port->sysrq)) {
handle_sysrq(ch);
port->sysrq = 0;
return 1;
}
port->sysrq = 0;
return 0;
}
static inline int
uart_prepare_sysrq_char(struct uart_port *port, unsigned int ch)
{
if (port->sysrq) {
if (ch && time_before(jiffies, port->sysrq)) {
port->sysrq_ch = ch;
port->sysrq = 0;
return 1;
}
if (!IS_ENABLED(CONFIG_MAGIC_SYSRQ_SERIAL))
return 0;
if (!port->has_sysrq && !IS_ENABLED(SUPPORT_SYSRQ))
return 0;
if (!port->sysrq)
return 0;
if (ch && time_before(jiffies, port->sysrq)) {
port->sysrq_ch = ch;
port->sysrq = 0;
return 1;
}
port->sysrq = 0;
return 0;
}
static inline void
@ -493,6 +507,11 @@ uart_unlock_and_check_sysrq(struct uart_port *port, unsigned long irqflags)
{
int sysrq_ch;
if (!port->has_sysrq && !IS_ENABLED(SUPPORT_SYSRQ)) {
spin_unlock_irqrestore(&port->lock, irqflags);
return;
}
sysrq_ch = port->sysrq_ch;
port->sysrq_ch = 0;
@ -501,17 +520,6 @@ uart_unlock_and_check_sysrq(struct uart_port *port, unsigned long irqflags)
if (sysrq_ch)
handle_sysrq(sysrq_ch);
}
#else
static inline int
uart_handle_sysrq_char(struct uart_port *port, unsigned int ch) { return 0; }
static inline int
uart_prepare_sysrq_char(struct uart_port *port, unsigned int ch) { return 0; }
static inline void
uart_unlock_and_check_sysrq(struct uart_port *port, unsigned long irqflags)
{
spin_unlock_irqrestore(&port->lock, irqflags);
}
#endif
/*
* We do the SysRQ and SAK checking like this...
@ -523,15 +531,16 @@ static inline int uart_handle_break(struct uart_port *port)
if (port->handle_break)
port->handle_break(port);
#ifdef SUPPORT_SYSRQ
if (port->cons && port->cons->index == port->line) {
if (!port->sysrq) {
port->sysrq = jiffies + HZ*5;
return 1;
if (port->has_sysrq || IS_ENABLED(SUPPORT_SYSRQ)) {
if (port->cons && port->cons->index == port->line) {
if (!port->sysrq) {
port->sysrq = jiffies + HZ*5;
return 1;
}
port->sysrq = 0;
}
port->sysrq = 0;
}
#endif
if (port->flags & UPF_SAK)
do_SAK(state->port.tty);
return 0;