serial: convert early_uart to earlycon for 8250
authorYinghai Lu <Yinghai.Lu@Sun.COM>
Mon, 16 Jul 2007 06:37:59 +0000 (23:37 -0700)
committerLinus Torvalds <torvalds@woody.linux-foundation.org>
Mon, 16 Jul 2007 16:05:35 +0000 (09:05 -0700)
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: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
15 files changed:
Documentation/kernel-parameters.txt
arch/ia64/kernel/setup.c
drivers/firmware/pcdp.c
drivers/serial/8250.c
drivers/serial/8250_early.c
drivers/serial/Kconfig
include/asm-i386/fixmap.h
include/asm-i386/io.h
include/asm-x86_64/fixmap.h
include/asm-x86_64/io.h
include/linux/console.h
include/linux/serial.h
include/linux/serial_8250.h
init/main.c
kernel/printk.c

index 4d880b3d1f35548083613a18d695d68029382c81..62aab585d9d7fd4353986f4e114967ac5470ed60 100644 (file)
@@ -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>]
index 188fb73c68456e3e2f1bd70e8f947b1b0754f869..4d9864cc92c90bb0fe7d31033db07bb76fbe84e4 100644 (file)
@@ -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;
 }
index 2b4b76e8bd723ac25b6aa57b55cf57e23736297a..58e9f8e457f833671813c4b71a20b252775efb4d 100644 (file)
@@ -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
index c84dab083a852b48ff7a55d1fbe87c79cd01e23a..0b3ec38ae6147e05ac8e02a917e1427adb4c46e8 100644 (file)
@@ -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
index 7e511199b4c5c91f09fcde69ced030c7ca15043d..947c20507e1f2a4bee47d64d918e9b3ecb167c45 100644 (file)
  * 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>
 #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);
index 2adbed4e10f350ac753d7db2f1be860eb01e6243..cab42cbd920db98df8d9941f5f0e466dfdfa6868 100644 (file)
@@ -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
index 80ea052ee3a4e1bce7f4c9f0f8564fffada8b538..249e753ac8053fd3c7b37ccf2a17eec20e2164aa 100644 (file)
@@ -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
index e797586a5bfc6fcbfa03cbcfe07ca40f07a81210..7b65b5b0003439c15852912d587ffc2a80ec293c 100644 (file)
@@ -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
index e90e1677531be3fdd0820771720a44c6845a5eac..2acb9b7f6418ba25b03c9c576b46843a9b8a9bf7 100644 (file)
@@ -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
index de2cd9a2303a92922a9dea817cd127841bf32765..7475095c5061b1634066f439c3112a209b6c7c29 100644 (file)
@@ -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.
index 62ef6e11d0d25cb49fc5c33951a89c8d2e8b62b3..c44d3dfde7a5199cf14e7e0ce643512af1d33b1e 100644 (file)
@@ -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;
index 33fc8cb8ddfbaedf234300c397a87b50895e1ec7..deb714314fb169de39bf195921c01b2a7e8085a6 100644 (file)
@@ -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 */
index 71310d80c09aae4d866f743baeb6e5ae932651e2..706ee9a4c80ca50d956c358e07630f68cf6669ed 100644 (file)
@@ -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
index 0eb1c7463fe4d08c3012ee66cb486c72122a26d5..038c7cb52390caf7ffe5b80b092f9dd9c80a8489 100644 (file)
@@ -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);
index 7ce9a8c1331282b4e37249f67fbda1a7fcb7a136..f46cc6dff46e6d90986a8018d9c60323a116b437 100644 (file)
@@ -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