Commit 18a8bd94 authored by Yinghai Lu's avatar Yinghai Lu Committed by Linus Torvalds

serial: convert early_uart to earlycon for 8250

Beacuse SERIAL_PORT_DFNS is removed from include/asm-i386/serial.h and
include/asm-x86_64/serial.h.  the serial8250_ports need to be probed late in
serial initializing stage.  the console_init=>serial8250_console_init=>
register_console=>serial8250_console_setup will return -ENDEV, and console
ttyS0 can not be enabled at that time.  need to wait till uart_add_one_port in
drivers/serial/serial_core.c to call register_console to get console ttyS0.
that is too late.

Make early_uart to use early_param, so uart console can be used earlier.  Make
it to be bootconsole with CON_BOOT flag, so can use console handover feature.
and it will switch to corresponding normal serial console automatically.

new command line will be:
	console=uart8250,io,0x3f8,9600n8
	console=uart8250,mmio,0xff5e0000,115200n8
or
	earlycon=uart8250,io,0x3f8,9600n8
	earlycon=uart8250,mmio,0xff5e0000,115200n8

it will print in very early stage:
	Early serial console at I/O port 0x3f8 (options '9600n8')
	console [uart0] enabled
later for console it will print:
	console handover: boot [uart0] -> real [ttyS0]

Signed-off-by: <yinghai.lu@sun.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Bjorn Helgaas <bjorn.helgaas@hp.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Gerd Hoffmann <kraxel@suse.de>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent b1c931e3
......@@ -462,13 +462,20 @@ and is between 256 and 4096 characters. It is defined in the file
Documentation/networking/netconsole.txt for an
alternative.
uart,io,<addr>[,options]
uart,mmio,<addr>[,options]
uart[8250],io,<addr>[,options]
uart[8250],mmio,<addr>[,options]
Start an early, polled-mode console on the 8250/16550
UART at the specified I/O port or MMIO address,
switching to the matching ttyS device later. The
options are the same as for ttyS, above.
earlycon= [KNL] Output early console device and options.
uart[8250],io,<addr>[,options]
uart[8250],mmio,<addr>[,options]
Start an early, polled-mode console on the 8250/16550
UART at the specified I/O port or MMIO address.
The options are the same as for ttyS, above.
cpcihp_generic= [HW,PCI] Generic port I/O CompactPCI driver
Format:
<first_slot>,<last_slot>,<port>,<enum_bit>[,<debug>]
......
......@@ -390,10 +390,6 @@ early_console_setup (char *cmdline)
if (!efi_setup_pcdp_console(cmdline))
earlycons++;
#endif
#ifdef CONFIG_SERIAL_8250_CONSOLE
if (!early_serial_console_init(cmdline))
earlycons++;
#endif
return (earlycons) ? 0 : -1;
}
......
......@@ -15,6 +15,7 @@
#include <linux/console.h>
#include <linux/efi.h>
#include <linux/serial.h>
#include <linux/serial_8250.h>
#include <asm/vga.h>
#include "pcdp.h"
......@@ -27,7 +28,7 @@ setup_serial_console(struct pcdp_uart *uart)
char parity;
mmio = (uart->addr.space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY);
p += sprintf(p, "console=uart,%s,0x%lx",
p += sprintf(p, "uart8250,%s,0x%lx",
mmio ? "mmio" : "io", uart->addr.address);
if (uart->baud) {
p += sprintf(p, ",%lu", uart->baud);
......@@ -41,7 +42,8 @@ setup_serial_console(struct pcdp_uart *uart)
}
}
return early_serial_console_init(options);
add_preferred_console("uart", 8250, &options[9]);
return setup_early_serial8250_console(options);
#else
return -ENODEV;
#endif
......
......@@ -2514,12 +2514,18 @@ static int __init serial8250_console_setup(struct console *co, char *options)
return uart_set_options(port, co, baud, parity, bits, flow);
}
static int __init serial8250_console_early_setup(void)
{
return serial8250_find_port_for_earlycon();
}
static struct uart_driver serial8250_reg;
static struct console serial8250_console = {
.name = "ttyS",
.write = serial8250_console_write,
.device = uart_console_device,
.setup = serial8250_console_setup,
.early_setup = serial8250_console_early_setup,
.flags = CON_PRINTBUFFER,
.index = -1,
.data = &serial8250_reg,
......@@ -2533,7 +2539,7 @@ static int __init serial8250_console_init(void)
}
console_initcall(serial8250_console_init);
static int __init find_port(struct uart_port *p)
int serial8250_find_port(struct uart_port *p)
{
int line;
struct uart_port *port;
......@@ -2546,26 +2552,6 @@ static int __init find_port(struct uart_port *p)
return -ENODEV;
}
int __init serial8250_start_console(struct uart_port *port, char *options)
{
int line;
line = find_port(port);
if (line < 0)
return -ENODEV;
add_preferred_console("ttyS", line, options);
printk("Adding console on ttyS%d at %s 0x%lx (options '%s')\n",
line, port->iotype == UPIO_MEM ? "MMIO" : "I/O port",
port->iotype == UPIO_MEM ? (unsigned long) port->mapbase :
(unsigned long) port->iobase, options);
if (!(serial8250_console.flags & CON_ENABLED)) {
serial8250_console.flags &= ~CON_PRINTBUFFER;
register_console(&serial8250_console);
}
return line;
}
#define SERIAL8250_CONSOLE &serial8250_console
#else
#define SERIAL8250_CONSOLE NULL
......
......@@ -17,13 +17,11 @@
* we locate the device directly by its MMIO or I/O port address.
*
* The user can specify the device directly, e.g.,
* console=uart,io,0x3f8,9600n8
* console=uart,mmio,0xff5e0000,115200n8
* or platform code can call early_uart_console_init() to set
* the early UART device.
*
* After the normal serial driver starts, we try to locate the
* matching ttyS device and start a console there.
* earlycon=uart8250,io,0x3f8,9600n8
* earlycon=uart8250,mmio,0xff5e0000,115200n8
* or
* console=uart8250,io,0x3f8,9600n8
* console=uart8250,mmio,0xff5e0000,115200n8
*/
#include <linux/tty.h>
......@@ -32,17 +30,21 @@
#include <linux/serial_core.h>
#include <linux/serial_reg.h>
#include <linux/serial.h>
#include <linux/serial_8250.h>
#include <asm/io.h>
#include <asm/serial.h>
#ifdef CONFIG_FIX_EARLYCON_MEM
#include <asm/pgtable.h>
#include <asm/fixmap.h>
#endif
struct early_uart_device {
struct early_serial8250_device {
struct uart_port port;
char options[16]; /* e.g., 115200n8 */
unsigned int baud;
};
static struct early_uart_device early_device __initdata;
static int early_uart_registered __initdata;
static struct early_serial8250_device early_device;
static unsigned int __init serial_in(struct uart_port *port, int offset)
{
......@@ -80,7 +82,7 @@ static void __init putc(struct uart_port *port, int c)
serial_out(port, UART_TX, c);
}
static void __init early_uart_write(struct console *console, const char *s, unsigned int count)
static void __init early_serial8250_write(struct console *console, const char *s, unsigned int count)
{
struct uart_port *port = &early_device.port;
unsigned int ier;
......@@ -111,7 +113,7 @@ static unsigned int __init probe_baud(struct uart_port *port)
return (port->uartclk / 16) / quot;
}
static void __init init_port(struct early_uart_device *device)
static void __init init_port(struct early_serial8250_device *device)
{
struct uart_port *port = &device->port;
unsigned int divisor;
......@@ -130,10 +132,9 @@ static void __init init_port(struct early_uart_device *device)
serial_out(port, UART_LCR, c & ~UART_LCR_DLAB);
}
static int __init parse_options(struct early_uart_device *device, char *options)
static int __init parse_options(struct early_serial8250_device *device, char *options)
{
struct uart_port *port = &device->port;
int mapsize = 64;
int mmio, length;
if (!options)
......@@ -143,12 +144,18 @@ static int __init parse_options(struct early_uart_device *device, char *options)
if (!strncmp(options, "mmio,", 5)) {
port->iotype = UPIO_MEM;
port->mapbase = simple_strtoul(options + 5, &options, 0);
port->membase = ioremap(port->mapbase, mapsize);
#ifdef CONFIG_FIX_EARLYCON_MEM
set_fixmap_nocache(FIX_EARLYCON_MEM_BASE, port->mapbase & PAGE_MASK);
port->membase = (void __iomem *)__fix_to_virt(FIX_EARLYCON_MEM_BASE);
port->membase += port->mapbase & ~PAGE_MASK;
#else
port->membase = ioremap(port->mapbase, 64);
if (!port->membase) {
printk(KERN_ERR "%s: Couldn't ioremap 0x%lx\n",
__FUNCTION__, port->mapbase);
return -ENOMEM;
}
#endif
mmio = 1;
} else if (!strncmp(options, "io,", 3)) {
port->iotype = UPIO_PORT;
......@@ -175,9 +182,16 @@ static int __init parse_options(struct early_uart_device *device, char *options)
return 0;
}
static int __init early_uart_setup(struct console *console, char *options)
static struct console early_serial8250_console __initdata = {
.name = "uart",
.write = early_serial8250_write,
.flags = CON_PRINTBUFFER | CON_BOOT,
.index = -1,
};
static int __init early_serial8250_setup(char *options)
{
struct early_uart_device *device = &early_device;
struct early_serial8250_device *device = &early_device;
int err;
if (device->port.membase || device->port.iobase)
......@@ -190,61 +204,48 @@ static int __init early_uart_setup(struct console *console, char *options)
return 0;
}
static struct console early_uart_console __initdata = {
.name = "uart",
.write = early_uart_write,
.setup = early_uart_setup,
.flags = CON_PRINTBUFFER,
.index = -1,
};
static int __init early_uart_console_init(void)
{
if (!early_uart_registered) {
register_console(&early_uart_console);
early_uart_registered = 1;
}
return 0;
}
console_initcall(early_uart_console_init);
int __init early_serial_console_init(char *cmdline)
int __init setup_early_serial8250_console(char *cmdline)
{
char *options;
int err;
options = strstr(cmdline, "console=uart,");
if (!options)
return -ENODEV;
options = strstr(cmdline, "uart8250,");
if (!options) {
options = strstr(cmdline, "uart,");
if (!options)
return 0;
}
options = strchr(cmdline, ',') + 1;
if ((err = early_uart_setup(NULL, options)) < 0)
if ((err = early_serial8250_setup(options)) < 0)
return err;
return early_uart_console_init();
register_console(&early_serial8250_console);
return 0;
}
static int __init early_uart_console_switch(void)
int __init serial8250_find_port_for_earlycon(void)
{
struct early_uart_device *device = &early_device;
struct early_serial8250_device *device = &early_device;
struct uart_port *port = &device->port;
int mmio, line;
int line;
int ret;
if (!(early_uart_console.flags & CON_ENABLED))
return 0;
if (!device->port.membase && !device->port.iobase)
return -ENODEV;
/* Try to start the normal driver on a matching line. */
mmio = (port->iotype == UPIO_MEM);
line = serial8250_start_console(port, device->options);
line = serial8250_find_port(port);
if (line < 0)
printk("No ttyS device at %s 0x%lx for console\n",
mmio ? "MMIO" : "I/O port",
mmio ? port->mapbase :
(unsigned long) port->iobase);
return -ENODEV;
unregister_console(&early_uart_console);
if (mmio)
iounmap(port->membase);
ret = update_console_cmdline("uart", 8250,
"ttyS", line, device->options);
if (ret < 0)
ret = update_console_cmdline("uart", 0,
"ttyS", line, device->options);
return 0;
return ret;
}
late_initcall(early_uart_console_switch);
early_param("earlycon", setup_early_serial8250_console);
......@@ -62,8 +62,22 @@ config SERIAL_8250_CONSOLE
kernel will automatically use the first serial line, /dev/ttyS0, as
system console.
you can set that using a kernel command line option such as
"console=uart8250,io,0x3f8,9600n8"
"console=uart8250,mmio,0xff5e0000,115200n8".
and it will switch to normal serial console when correponding port is
ready.
"earlycon=uart8250,io,0x3f8,9600n8"
"earlycon=uart8250,mmio,0xff5e0000,115200n8".
it will not only setup early console.
If unsure, say N.
config FIX_EARLYCON_MEM
bool
depends on X86
default y
config SERIAL_8250_GSC
tristate
depends on SERIAL_8250 && GSC
......
......@@ -54,6 +54,8 @@ extern unsigned long __FIXADDR_TOP;
enum fixed_addresses {
FIX_HOLE,
FIX_VDSO,
FIX_DBGP_BASE,
FIX_EARLYCON_MEM_BASE,
#ifdef CONFIG_X86_LOCAL_APIC
FIX_APIC_BASE, /* local (CPU) APIC) -- required for SMP or not */
#endif
......
......@@ -129,6 +129,7 @@ extern void iounmap(volatile void __iomem *addr);
*/
extern void *bt_ioremap(unsigned long offset, unsigned long size);
extern void bt_iounmap(void *addr, unsigned long size);
extern void __iomem *fix_ioremap(unsigned idx, unsigned long phys);
/* Use early IO mappings for DMI because it's initialized early */
#define dmi_ioremap bt_ioremap
......
......@@ -35,6 +35,8 @@ enum fixed_addresses {
VSYSCALL_LAST_PAGE,
VSYSCALL_FIRST_PAGE = VSYSCALL_LAST_PAGE + ((VSYSCALL_END-VSYSCALL_START) >> PAGE_SHIFT) - 1,
VSYSCALL_HPET,
FIX_DBGP_BASE,
FIX_EARLYCON_MEM_BASE,
FIX_HPET_BASE,
FIX_APIC_BASE, /* local (CPU) APIC) -- required for SMP or not */
FIX_IO_APIC_BASE_0,
......@@ -84,7 +86,7 @@ static __always_inline unsigned long fix_to_virt(const unsigned int idx)
if (idx >= __end_of_fixed_addresses)
__this_fixmap_does_not_exist();
return __fix_to_virt(idx);
return __fix_to_virt(idx);
}
#endif
......@@ -144,6 +144,7 @@ extern void early_iounmap(void *addr, unsigned long size);
*/
extern void __iomem * ioremap_nocache (unsigned long offset, unsigned long size);
extern void iounmap(volatile void __iomem *addr);
extern void __iomem *fix_ioremap(unsigned idx, unsigned long phys);
/*
* ISA I/O bus memory addresses are 1:1 with the physical address.
......
......@@ -99,6 +99,7 @@ struct console {
struct tty_driver *(*device)(struct console *, int *);
void (*unblank)(void);
int (*setup)(struct console *, char *);
int (*early_setup)(void);
short flags;
short index;
int cflag;
......@@ -107,6 +108,7 @@ struct console {
};
extern int add_preferred_console(char *name, int idx, char *options);
extern int update_console_cmdline(char *name, int idx, char *name_new, int idx_new, char *options);
extern void register_console(struct console *);
extern int unregister_console(struct console *);
extern struct console *console_drivers;
......
......@@ -177,11 +177,5 @@ struct serial_icounter_struct {
#ifdef __KERNEL__
#include <linux/compiler.h>
/* Allow architectures to override entries in serial8250_ports[] at run time: */
struct uart_port; /* forward declaration */
extern int early_serial_setup(struct uart_port *port);
extern int early_serial_console_init(char *options);
extern int serial8250_start_console(struct uart_port *port, char *options);
#endif /* __KERNEL__ */
#endif /* _LINUX_SERIAL_H */
......@@ -60,4 +60,8 @@ void serial8250_unregister_port(int line);
void serial8250_suspend_port(int line);
void serial8250_resume_port(int line);
extern int serial8250_find_port(struct uart_port *p);
extern int serial8250_find_port_for_earlycon(void);
extern int setup_early_serial8250_console(char *cmdline);
#endif
......@@ -453,7 +453,10 @@ static int __init do_early_param(char *param, char *val)
struct obs_kernel_param *p;
for (p = __setup_start; p < __setup_end; p++) {
if (p->early && strcmp(param, p->str) == 0) {
if ((p->early && strcmp(param, p->str) == 0) ||
(strcmp(param, "console") == 0 &&
strcmp(p->str, "earlycon") == 0)
) {
if (p->setup_func(val) != 0)
printk(KERN_WARNING
"Malformed early option '%s'\n", param);
......
......@@ -726,6 +726,25 @@ int __init add_preferred_console(char *name, int idx, char *options)
return 0;
}
int __init update_console_cmdline(char *name, int idx, char *name_new, int idx_new, char *options)
{
struct console_cmdline *c;
int i;
for (i = 0; i < MAX_CMDLINECONSOLES && console_cmdline[i].name[0]; i++)
if (strcmp(console_cmdline[i].name, name) == 0 &&
console_cmdline[i].index == idx) {
c = &console_cmdline[i];
memcpy(c->name, name_new, sizeof(c->name));
c->name[sizeof(c->name) - 1] = 0;
c->options = options;
c->index = idx_new;
return i;
}
/* not found */
return -1;
}
#ifndef CONFIG_DISABLE_CONSOLE_SUSPEND
/**
* suspend_console - suspend the console subsystem
......@@ -942,6 +961,9 @@ void register_console(struct console *console)
if (preferred_console < 0 || bootconsole || !console_drivers)
preferred_console = selected_console;
if (console->early_setup)
console->early_setup();
/*
* See if we want to use this console driver. If we
* didn't select a console we take the first one
......
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