2007-05-30 01:49:44

by Yinghai Lu

[permalink] [raw]
Subject: [PATCH 4/5] serial: convert early_uart to earlycon for 8250

[PATCH 4/5] 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: <[email protected]>

Documentation/kernel-parameters.txt | 11 +++
arch/ia64/kernel/setup.c | 4 -
drivers/serial/8250.c | 28 ++-------
drivers/serial/8250_early.c | 104 ++++++++++++++----------------------
drivers/serial/Kconfig | 10 +++
include/asm-i386/fixmap.h | 2
include/asm-i386/io.h | 13 ++++
include/asm-ia64/io.h | 4 +
include/asm-x86_64/fixmap.h | 4 +
include/asm-x86_64/io.h | 13 ++++
include/linux/console.h | 2
include/linux/serial.h | 6 --
include/linux/serial_8250.h | 3 +
init/main.c | 5 +
kernel/printk.c | 22 +++++++
15 files changed, 133 insertions(+), 98 deletions(-)

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index aae2282..b51fbac 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -464,13 +464,20 @@ 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]
+ uart8250,io,<addr>[,options]
+ uart8250,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.
+ uart8250,io,<addr>[,options]
+ uart8250,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>]
diff --git a/arch/ia64/kernel/setup.c b/arch/ia64/kernel/setup.c
index eaa6a24..dd7f95b 100644
--- a/arch/ia64/kernel/setup.c
+++ b/arch/ia64/kernel/setup.c
@@ -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;
}
diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c
index c84dab0..0b3ec38 100644
--- a/drivers/serial/8250.c
+++ b/drivers/serial/8250.c
@@ -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
diff --git a/drivers/serial/8250_early.c b/drivers/serial/8250_early.c
index 7e51119..820d164 100644
--- a/drivers/serial/8250_early.c
+++ b/drivers/serial/8250_early.c
@@ -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 +30,17 @@
#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>

-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 +78,7 @@ 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 +109,7 @@ 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 +128,9 @@ 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 +140,7 @@ 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);
- if (!port->membase) {
- printk(KERN_ERR "%s: Couldn't ioremap 0x%lx\n",
- __FUNCTION__, port->mapbase);
- return -ENOMEM;
- }
+ port->membase = fix_ioremap(FIX_EARLYCON_MEM_BASE, port->mapbase);
mmio = 1;
} else if (!strncmp(options, "io,", 3)) {
port->iotype = UPIO_PORT;
@@ -175,9 +167,16 @@ 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,
+ .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 +189,40 @@ 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)
+static int __init setup_early_serial8250_console(char *cmdline)
{
char *options;
int err;

- options = strstr(cmdline, "console=uart,");
+ options = strstr(cmdline, "uart8250,");
if (!options)
- return -ENODEV;
+ 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();
+
+ early_serial8250_console.flags |= CON_BOOT;
+ register_console(&early_serial8250_console);
+
+ return 0;
}

-static int __init early_uart_console_switch(void)
+int 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;

- 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);
-
- unregister_console(&early_uart_console);
- if (mmio)
- iounmap(port->membase);
+ return -ENODEV;

- return 0;
+ return update_console_cmdline("uart", 8250,
+ "ttyS", line, device->options);
}
-late_initcall(early_uart_console_switch);
+
+early_param("earlycon", setup_early_serial8250_console);
diff --git a/drivers/serial/Kconfig b/drivers/serial/Kconfig
index 315ea99..4a43fd6 100644
--- a/drivers/serial/Kconfig
+++ b/drivers/serial/Kconfig
@@ -62,6 +62,16 @@ 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 SERIAL_8250_GSC
diff --git a/include/asm-i386/fixmap.h b/include/asm-i386/fixmap.h
index 80ea052..249e753 100644
--- a/include/asm-i386/fixmap.h
+++ b/include/asm-i386/fixmap.h
@@ -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
diff --git a/include/asm-i386/io.h b/include/asm-i386/io.h
index e797586..6c8748d 100644
--- a/include/asm-i386/io.h
+++ b/include/asm-i386/io.h
@@ -130,6 +130,19 @@ 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);

+#include <asm/pgtable.h>
+#include <asm/fixmap.h>
+
+static inline void __iomem * fix_ioremap (unsigned idx, unsigned long phys)
+{
+ void __iomem * vaddr;
+ set_fixmap_nocache(idx, phys & PAGE_MASK);
+ vaddr = (void __iomem *)__fix_to_virt(idx);
+ vaddr += phys & ~PAGE_MASK;
+
+ return vaddr;
+}
+
/* Use early IO mappings for DMI because it's initialized early */
#define dmi_ioremap bt_ioremap
#define dmi_iounmap bt_iounmap
diff --git a/include/asm-ia64/io.h b/include/asm-ia64/io.h
index eb17a86..e29eaf8 100644
--- a/include/asm-ia64/io.h
+++ b/include/asm-ia64/io.h
@@ -423,6 +423,10 @@ extern void __iomem * ioremap(unsigned long offset, unsigned long size);
extern void __iomem * ioremap_nocache (unsigned long offset, unsigned long size);
extern void iounmap (volatile void __iomem *addr);

+/* for console=uart8250,mmio,0xffe5000,9600n8 */
+#define FIX_EARLYCON_MEM_BASE 1
+#define fix_ioremap(idx, phys) ioremap(phys, 64)
+
/* Use normal IO mappings for DMI */
#define dmi_ioremap ioremap
#define dmi_iounmap(x,l) iounmap(x)
diff --git a/include/asm-x86_64/fixmap.h b/include/asm-x86_64/fixmap.h
index e90e167..2acb9b7 100644
--- a/include/asm-x86_64/fixmap.h
+++ b/include/asm-x86_64/fixmap.h
@@ -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
diff --git a/include/asm-x86_64/io.h b/include/asm-x86_64/io.h
index de2cd9a..e2d66de 100644
--- a/include/asm-x86_64/io.h
+++ b/include/asm-x86_64/io.h
@@ -145,6 +145,19 @@ 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);

+#include <asm/pgtable.h>
+#include <asm/fixmap.h>
+
+static inline void __iomem * fix_ioremap (unsigned idx, unsigned long phys)
+{
+ void __iomem * vaddr;
+ set_fixmap_nocache(idx, phys & PAGE_MASK);
+ vaddr = (void __iomem *)__fix_to_virt(idx);
+ vaddr += phys & ~PAGE_MASK;
+
+ return vaddr;
+}
+
/*
* ISA I/O bus memory addresses are 1:1 with the physical address.
*/
diff --git a/include/linux/console.h b/include/linux/console.h
index 62ef6e1..c44d3df 100644
--- a/include/linux/console.h
+++ b/include/linux/console.h
@@ -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;
diff --git a/include/linux/serial.h b/include/linux/serial.h
index 33fc8cb..deb7143 100644
--- a/include/linux/serial.h
+++ b/include/linux/serial.h
@@ -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 */
diff --git a/include/linux/serial_8250.h b/include/linux/serial_8250.h
index 71310d8..23519fb 100644
--- a/include/linux/serial_8250.h
+++ b/include/linux/serial_8250.h
@@ -60,4 +60,7 @@ 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);
+
#endif
diff --git a/init/main.c b/init/main.c
index eb8bdba..58dbe75 100644
--- a/init/main.c
+++ b/init/main.c
@@ -452,7 +452,10 @@ 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);
diff --git a/kernel/printk.c b/kernel/printk.c
index 0bbdeac..7b96cae 100644
--- a/kernel/printk.c
+++ b/kernel/printk.c
@@ -726,6 +726,25 @@ int __init add_preferred_console(char *name, int idx, char *options)
return 0;
}

+int 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


2007-05-30 18:58:00

by Andrew Morton

[permalink] [raw]
Subject: Re: [PATCH 4/5] serial: convert early_uart to earlycon for 8250

On Tue, 29 May 2007 18:43:59 -0700
Yinghai Lu <[email protected]> wrote:

> [PATCH 4/5] 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]
>
>
> Documentation/kernel-parameters.txt | 11 +++
> arch/ia64/kernel/setup.c | 4 -
> drivers/serial/8250.c | 28 ++-------
> drivers/serial/8250_early.c | 104 ++++++++++++++----------------------
> drivers/serial/Kconfig | 10 +++
> include/asm-i386/fixmap.h | 2
> include/asm-i386/io.h | 13 ++++
> include/asm-ia64/io.h | 4 +
> include/asm-x86_64/fixmap.h | 4 +
> include/asm-x86_64/io.h | 13 ++++
> include/linux/console.h | 2
> include/linux/serial.h | 6 --
> include/linux/serial_8250.h | 3 +
> init/main.c | 5 +
> kernel/printk.c | 22 +++++++
> 15 files changed, 133 insertions(+), 98 deletions(-)

This is a lot of tricky stuff in areas which I'm not very familar with.
Need help, am not getting it.

> @@ -143,12 +140,7 @@ 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);
> - if (!port->membase) {
> - printk(KERN_ERR "%s: Couldn't ioremap 0x%lx\n",
> - __FUNCTION__, port->mapbase);
> - return -ENOMEM;
> - }
> + port->membase = fix_ioremap(FIX_EARLYCON_MEM_BASE, port->mapbase);

A number of useful-looking warnigns such as the above got removed. How come?

> mmio = 1;
> } else if (!strncmp(options, "io,", 3)) {
> port->iotype = UPIO_PORT;
> @@ -175,9 +167,16 @@ 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,

Should this have CON_BOOT set as well?

See
ftp://ftp.kernel.org/pub/linux/kernel/people/akpm/patches/2.6/2.6.21-rc7/2.6.21-rc7-mm2/broken-out/fixes-and-cleanups-for-earlyprintk-aka-boot-console.patch,
which is now in mainline.

> + .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 +189,40 @@ 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,
> -};

hm, that didn't have CON_BOOT.

> +static inline void __iomem * fix_ioremap (unsigned idx, unsigned long phys)

I don't suppose it'd help much if I were to complain about the coding style
(no space after the * or after the function name, please).

> +{
> + void __iomem * vaddr;
> + set_fixmap_nocache(idx, phys & PAGE_MASK);
> + vaddr = (void __iomem *)__fix_to_virt(idx);
> + vaddr += phys & ~PAGE_MASK;
> +
> + return vaddr;
> +}

Probably this was a bit too large for inlining.

> /* Use early IO mappings for DMI because it's initialized early */
> #define dmi_ioremap bt_ioremap
> #define dmi_iounmap bt_iounmap
> diff --git a/include/asm-ia64/io.h b/include/asm-ia64/io.h
> index eb17a86..e29eaf8 100644
> --- a/include/asm-ia64/io.h
> +++ b/include/asm-ia64/io.h
> @@ -423,6 +423,10 @@ extern void __iomem * ioremap(unsigned long offset, unsigned long size);
> extern void __iomem * ioremap_nocache (unsigned long offset, unsigned long size);
> extern void iounmap (volatile void __iomem *addr);
>
> +/* for console=uart8250,mmio,0xffe5000,9600n8 */
> +#define FIX_EARLYCON_MEM_BASE 1
> +#define fix_ioremap(idx, phys) ioremap(phys, 64)
> +
> /* Use normal IO mappings for DMI */
> #define dmi_ioremap ioremap
> #define dmi_iounmap(x,l) iounmap(x)

So we touch ia64 as well?

>
> +int 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;
> +}

Shouldn't this be __init?

serial8250_find_port_for_earlycon() had its __init removed. Why?


This patch conflicts with David's
serial-use-resource_size_t-for-port-io-addresses.patch in minor ways, but
there may be functional conflicts as well. David's patch seems to be a bit
stuck, so I'll drop it and I'll merge these instead. But I don't know what
I'm doing.

2007-05-30 19:59:30

by Yinghai Lu

[permalink] [raw]
Subject: Re: [PATCH 4/5] serial: convert early_uart to earlycon for 8250

Andrew Morton wrote:
> On Tue, 29 May 2007 18:43:59 -0700
> Yinghai Lu <[email protected]> wrote:
>
>> [PATCH 4/5] 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]
>>
>>
>> Documentation/kernel-parameters.txt | 11 +++
>> arch/ia64/kernel/setup.c | 4 -
>> drivers/serial/8250.c | 28 ++-------
>> drivers/serial/8250_early.c | 104 ++++++++++++++----------------------
>> drivers/serial/Kconfig | 10 +++
>> include/asm-i386/fixmap.h | 2
>> include/asm-i386/io.h | 13 ++++
>> include/asm-ia64/io.h | 4 +
>> include/asm-x86_64/fixmap.h | 4 +
>> include/asm-x86_64/io.h | 13 ++++
>> include/linux/console.h | 2
>> include/linux/serial.h | 6 --
>> include/linux/serial_8250.h | 3 +
>> init/main.c | 5 +
>> kernel/printk.c | 22 +++++++
>> 15 files changed, 133 insertions(+), 98 deletions(-)
>
> This is a lot of tricky stuff in areas which I'm not very familar with.
> Need help, am not getting it.
>
>> @@ -143,12 +140,7 @@ 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);
>> - if (!port->membase) {
>> - printk(KERN_ERR "%s: Couldn't ioremap 0x%lx\n",
>> - __FUNCTION__, port->mapbase);
>> - return -ENOMEM;
>> - }
>> + port->membase = fix_ioremap(FIX_EARLYCON_MEM_BASE, port->mapbase);
>
> A number of useful-looking warnigns such as the above got removed. How come?
earycon, when you can not get fix_ioremap work, you can not get anything from boot.
>
>> mmio = 1;
>> } else if (!strncmp(options, "io,", 3)) {
>> port->iotype = UPIO_PORT;
>> @@ -175,9 +167,16 @@ 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,
>
> Should this have CON_BOOT set as well?
>
> See
> ftp://ftp.kernel.org/pub/linux/kernel/people/akpm/patches/2.6/2.6.21-rc7/2.6.21-rc7-mm2/broken-out/fixes-and-cleanups-for-earlyprintk-aka-boot-console.patch,
> which is now in mainline.
>

I put that into setup_early_serial8250_console.

-int __init early_serial_console_init(char *cmdline)
+static int __init setup_early_serial8250_console(char *cmdline)
{
char *options;
int err;

- options = strstr(cmdline, "console=uart,");
+ options = strstr(cmdline, "uart8250,");
if (!options)
- return -ENODEV;
+ 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();
+
+ early_serial8250_console.flags |= CON_BOOT;
+ register_console(&early_serial8250_console);
+
+ return 0;
}

we may use
>> + .flags = CON_PRINTBUFFER | CAN_BOOT;

instead that line.


>> + .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 +189,40 @@ 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,
>> -};
>
> hm, that didn't have CON_BOOT.
>
>> +static inline void __iomem * fix_ioremap (unsigned idx, unsigned long phys)
>
> I don't suppose it'd help much if I were to complain about the coding style
> (no space after the * or after the function name, please).
>
>> +{
>> + void __iomem * vaddr;
>> + set_fixmap_nocache(idx, phys & PAGE_MASK);
>> + vaddr = (void __iomem *)__fix_to_virt(idx);
>> + vaddr += phys & ~PAGE_MASK;
>> +
>> + return vaddr;
>> +}
>
> Probably this was a bit too large for inlining.

current only one calling, later will use that for usb debug cable.

>
>> /* Use early IO mappings for DMI because it's initialized early */
>> #define dmi_ioremap bt_ioremap
>> #define dmi_iounmap bt_iounmap
>> diff --git a/include/asm-ia64/io.h b/include/asm-ia64/io.h
>> index eb17a86..e29eaf8 100644
>> --- a/include/asm-ia64/io.h
>> +++ b/include/asm-ia64/io.h
>> @@ -423,6 +423,10 @@ extern void __iomem * ioremap(unsigned long offset, unsigned long size);
>> extern void __iomem * ioremap_nocache (unsigned long offset, unsigned long size);
>> extern void iounmap (volatile void __iomem *addr);
>>
>> +/* for console=uart8250,mmio,0xffe5000,9600n8 */
>> +#define FIX_EARLYCON_MEM_BASE 1
>> +#define fix_ioremap(idx, phys) ioremap(phys, 64)
>> +
>> /* Use normal IO mappings for DMI */
>> #define dmi_ioremap ioremap
>> #define dmi_iounmap(x,l) iounmap(x)
>
> So we touch ia64 as well?
>
>>
>> +int 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;
>> +}
>
> Shouldn't this be __init?
>
> serial8250_find_port_for_earlycon() had its __init removed. Why?
with __init, the compiler will cry about .init.text and .text missection.

YH

2007-05-30 20:18:51

by Andrew Morton

[permalink] [raw]
Subject: Re: [PATCH 4/5] serial: convert early_uart to earlycon for 8250

On Wed, 30 May 2007 12:58:11 -0700
Yinghai Lu <[email protected]> wrote:

> >> +int 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;
> >> +}
> >
> > Shouldn't this be __init?
> >
> > serial8250_find_port_for_earlycon() had its __init removed. Why?
> with __init, the compiler will cry about .init.text and .text missection.

But was this the correct fix for that? afaict the only caller of
this function is __init anyway.

2007-05-30 21:06:00

by Yinghai Lu

[permalink] [raw]
Subject: Re: [PATCH 4/5] serial: convert early_uart to earlycon for 8250

On Wednesday 30 May 2007 13:18, Andrew Morton wrote:
> On Wed, 30 May 2007 12:58:11 -0700
> Yinghai Lu <[email protected]> wrote:
>
> > >> +int 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;
> > >> +}
> > >
> > > Shouldn't this be __init?
> > >
> > > serial8250_find_port_for_earlycon() had its __init removed. Why?
> > with __init, the compiler will cry about .init.text and .text missection.
>
> But was this the correct fix for that? afaict the only caller of
> this function is __init anyway.
>
You are right.
serial8250_find_port_for_earlycon and
update_console_cmdline in kernel/printk.c
could be __init

YH

2007-05-30 21:49:45

by Andrew Morton

[permalink] [raw]
Subject: Re: [PATCH 4/5] serial: convert early_uart to earlycon for 8250

On Wed, 30 May 2007 13:58:52 -0700
Yinghai Lu <[email protected]> wrote:

> On Wednesday 30 May 2007 13:18, Andrew Morton wrote:
> > On Wed, 30 May 2007 12:58:11 -0700
> > Yinghai Lu <[email protected]> wrote:
> >
> > > >> +int 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;
> > > >> +}
> > > >
> > > > Shouldn't this be __init?
> > > >
> > > > serial8250_find_port_for_earlycon() had its __init removed. Why?
> > > with __init, the compiler will cry about .init.text and .text missection.
> >
> > But was this the correct fix for that? afaict the only caller of
> > this function is __init anyway.
> >
> You are right.
> serial8250_find_port_for_earlycon and
> update_console_cmdline in kernel/printk.c
> could be __init

OK, please send a fixup sometime.

2007-05-31 03:13:58

by Andrew Morton

[permalink] [raw]
Subject: Re: [PATCH 4/5] serial: convert early_uart to earlycon for 8250

On Tue, 29 May 2007 18:43:59 -0700 Yinghai Lu <[email protected]> wrote:

> [PATCH 4/5] serial: convert early_uart to earlycon for 8250

drivers/serial/8250_early.c: In function 'parse_options':
drivers/serial/8250_early.c:143: error: 'FIX_EARLYCON_MEM_BASE' undeclared (first use in this function)
drivers/serial/8250_early.c:143: error: (Each undeclared identifier is reported only once

That was with http://userweb.kernel.org/~akpm/config-sony.txt, but this is
going to break a whole pile of architectures (alpha, powerpc, others).

I think I'll give up on it now.

2007-05-31 04:34:43

by Yinghai Lu

[permalink] [raw]
Subject: Re: [PATCH 4/5] serial: convert early_uart to earlycon for 8250

On 5/30/07, Andrew Morton <[email protected]> wrote:
> On Tue, 29 May 2007 18:43:59 -0700 Yinghai Lu <[email protected]> wrote:
>
> > [PATCH 4/5] serial: convert early_uart to earlycon for 8250
>
> drivers/serial/8250_early.c: In function 'parse_options':
> drivers/serial/8250_early.c:143: error: 'FIX_EARLYCON_MEM_BASE' undeclared (first use in this function)
> drivers/serial/8250_early.c:143: error: (Each undeclared identifier is reported only once
>
> That was with http://userweb.kernel.org/~akpm/config-sony.txt, but this is
> going to break a whole pile of architectures (alpha, powerpc, others).

alpha, powerpc, others may need sth like ia64, if they do not support fixmap.

diff --git a/include/asm-ia64/io.h b/include/asm-ia64/io.h
index eb17a86..e29eaf8 100644
--- a/include/asm-ia64/io.h
+++ b/include/asm-ia64/io.h
@@ -423,6 +423,10 @@ extern void __iomem * ioremap(unsigned long
offset, unsigned long size);
extern void __iomem * ioremap_nocache (unsigned long offset, unsigned
long size);
extern void iounmap (volatile void __iomem *addr);

+/* for console=uart8250,mmio,0xffe5000,9600n8 */
+#define FIX_EARLYCON_MEM_BASE 1
+#define fix_ioremap(idx, phys) ioremap(phys, 64)
+
/* Use normal IO mappings for DMI */
#define dmi_ioremap ioremap
#define dmi_iounmap(x,l) iounmap(x)


$ find . -name "fixmap.h"
./asm-sh/fixmap.h
./asm-um/fixmap.h
./asm-parisc/fixmap.h
./asm-x86_64/fixmap.h
./asm-sparc/fixmap.h
./asm-i386/fixmap.h
./asm-mips/fixmap.h

they will need
diff --git a/include/asm-x86_64/io.h b/include/asm-x86_64/io.h
index de2cd9a..e2d66de 100644
--- a/include/asm-x86_64/io.h
+++ b/include/asm-x86_64/io.h
@@ -145,6 +145,19 @@ 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);

+#include <asm/pgtable.h>
+#include <asm/fixmap.h>
+
+static inline void __iomem * fix_ioremap (unsigned idx, unsigned long phys)
+{
+ void __iomem * vaddr;
+ set_fixmap_nocache(idx, phys & PAGE_MASK);
+ vaddr = (void __iomem *)__fix_to_virt(idx);
+ vaddr += phys & ~PAGE_MASK;
+
+ return vaddr;
+}
+
/*
* ISA I/O bus memory addresses are 1:1 with the physical address.
*/

YH

2007-05-31 04:36:49

by Yinghai Lu

[permalink] [raw]
Subject: Re: [PATCH 4/5] serial: convert early_uart to earlycon for 8250

On 5/30/07, Yinghai Lu <[email protected]> wrote:
> On 5/30/07, Andrew Morton <[email protected]> wrote:
> > On Tue, 29 May 2007 18:43:59 -0700 Yinghai Lu <[email protected]> wrote:
> >
> > > [PATCH 4/5] serial: convert early_uart to earlycon for 8250
> >
> > drivers/serial/8250_early.c: In function 'parse_options':
> > drivers/serial/8250_early.c:143: error: 'FIX_EARLYCON_MEM_BASE' undeclared (first use in this function)
> > drivers/serial/8250_early.c:143: error: (Each undeclared identifier is reported only once
> >
> > That was with http://userweb.kernel.org/~akpm/config-sony.txt, but this is
> > going to break a whole pile of architectures (alpha, powerpc, others).
>
> alpha, powerpc, others may need sth like ia64, if they do not support fixmap.
>
>

or create dummy fixmap.h that doesn't support fixmap.

YH

2007-05-31 04:40:27

by Andrew Morton

[permalink] [raw]
Subject: Re: [PATCH 4/5] serial: convert early_uart to earlycon for 8250

On Wed, 30 May 2007 21:34:35 -0700 "Yinghai Lu" <[email protected]> wrote:

> they will need
> diff --git a/include/asm-x86_64/io.h b/include/asm-x86_64/io.h
> index de2cd9a..e2d66de 100644
> --- a/include/asm-x86_64/io.h
> +++ b/include/asm-x86_64/io.h
> @@ -145,6 +145,19 @@ 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);
>
> +#include <asm/pgtable.h>
> +#include <asm/fixmap.h>
> +
> +static inline void __iomem * fix_ioremap (unsigned idx, unsigned long phys)
> +{
> + void __iomem * vaddr;
> + set_fixmap_nocache(idx, phys & PAGE_MASK);
> + vaddr = (void __iomem *)__fix_to_virt(idx);
> + vaddr += phys & ~PAGE_MASK;
> +
> + return vaddr;
> +}
> +

I hope not - I just removed that inlined function. It's too large and the
inclusion of pgtable.h in io.h causes all sorts of problems.

This function should go into arch/.../mm/ioremap.c

2007-05-31 04:42:36

by Yinghai Lu

[permalink] [raw]
Subject: Re: [PATCH 4/5] serial: convert early_uart to earlycon for 8250

On 5/30/07, Andrew Morton <[email protected]> wrote:
> On Wed, 30 May 2007 21:34:35 -0700 "Yinghai Lu" <[email protected]> wrote:
>
> > they will need
> > diff --git a/include/asm-x86_64/io.h b/include/asm-x86_64/io.h
> > index de2cd9a..e2d66de 100644
> > --- a/include/asm-x86_64/io.h
> > +++ b/include/asm-x86_64/io.h
> > @@ -145,6 +145,19 @@ 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);
> >
> > +#include <asm/pgtable.h>
> > +#include <asm/fixmap.h>
> > +
> > +static inline void __iomem * fix_ioremap (unsigned idx, unsigned long phys)
> > +{
> > + void __iomem * vaddr;
> > + set_fixmap_nocache(idx, phys & PAGE_MASK);
> > + vaddr = (void __iomem *)__fix_to_virt(idx);
> > + vaddr += phys & ~PAGE_MASK;
> > +
> > + return vaddr;
> > +}
> > +
>
> I hope not - I just removed that inlined function. It's too large and the
> inclusion of pgtable.h in io.h causes all sorts of problems.
>
> This function should go into arch/.../mm/ioremap.c
>
agree, but need to keep

#include <asm/fixmap.h>

and will create dummy fixmap.h for arch that doesn't support fixmap

YH

2007-05-31 04:49:40

by Andrew Morton

[permalink] [raw]
Subject: Re: [PATCH 4/5] serial: convert early_uart to earlycon for 8250

On Wed, 30 May 2007 21:36:41 -0700 "Yinghai Lu" <[email protected]> wrote:

> On 5/30/07, Yinghai Lu <[email protected]> wrote:
> > On 5/30/07, Andrew Morton <[email protected]> wrote:
> > > On Tue, 29 May 2007 18:43:59 -0700 Yinghai Lu <[email protected]> wrote:
> > >
> > > > [PATCH 4/5] serial: convert early_uart to earlycon for 8250
> > >
> > > drivers/serial/8250_early.c: In function 'parse_options':
> > > drivers/serial/8250_early.c:143: error: 'FIX_EARLYCON_MEM_BASE' undeclared (first use in this function)
> > > drivers/serial/8250_early.c:143: error: (Each undeclared identifier is reported only once
> > >
> > > That was with http://userweb.kernel.org/~akpm/config-sony.txt, but this is
> > > going to break a whole pile of architectures (alpha, powerpc, others).
> >
> > alpha, powerpc, others may need sth like ia64, if they do not support fixmap.
> >
> >
>
> or create dummy fixmap.h that doesn't support fixmap.
>

You could require that the architecture implement some specific function
for mapping the early-uart. Say,

void __iomem *map_early_uart(unsigned long phys_addr, unsigned long len);
void unmap_early_uart(void * __iomem *addr);

then, in drivers/serial/8250_early.c, do


void __iomem * __attribute__((weak))
map_early_uart(unsigned long phys_addr, unsigned long len)
{
return ioremap(phys_addr, len);
}

void __attribute__((weak)) unmap_early_uart(void * __iomem *addr)
{
iounmap(addr);
}

and in arch/i386/mm/ioremap.c



#ifdef CONFIG_something

void __iomem *map_early_uart(unsigned long phys_addr, unsigned long len)
{
void __iomem * vaddr;
set_fixmap_nocache(idx, phys & PAGE_MASK);
vaddr = (void __iomem *)__fix_to_virt(idx);
vaddr += phys & ~PAGE_MASK;

return vaddr;
}

void unmap_early_uart(void * __iomem *addr)
{
/* nothing to do */
}

#endif

or such.

2007-05-31 04:51:43

by Andrew Morton

[permalink] [raw]
Subject: Re: [PATCH 4/5] serial: convert early_uart to earlycon for 8250

On Wed, 30 May 2007 21:42:15 -0700 "Yinghai Lu" <[email protected]> wrote:

> On 5/30/07, Andrew Morton <[email protected]> wrote:
> > On Wed, 30 May 2007 21:34:35 -0700 "Yinghai Lu" <[email protected]> wrote:
> >
> > > they will need
> > > diff --git a/include/asm-x86_64/io.h b/include/asm-x86_64/io.h
> > > index de2cd9a..e2d66de 100644
> > > --- a/include/asm-x86_64/io.h
> > > +++ b/include/asm-x86_64/io.h
> > > @@ -145,6 +145,19 @@ 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);
> > >
> > > +#include <asm/pgtable.h>
> > > +#include <asm/fixmap.h>
> > > +
> > > +static inline void __iomem * fix_ioremap (unsigned idx, unsigned long phys)
> > > +{
> > > + void __iomem * vaddr;
> > > + set_fixmap_nocache(idx, phys & PAGE_MASK);
> > > + vaddr = (void __iomem *)__fix_to_virt(idx);
> > > + vaddr += phys & ~PAGE_MASK;
> > > +
> > > + return vaddr;
> > > +}
> > > +
> >
> > I hope not - I just removed that inlined function. It's too large and the
> > inclusion of pgtable.h in io.h causes all sorts of problems.
> >
> > This function should go into arch/.../mm/ioremap.c
> >
> agree, but need to keep
>
> #include <asm/fixmap.h>

No, there's no need for that and it is undesirable.

> and will create dummy fixmap.h for arch that doesn't support fixmap

So's that. If we avoid the inlined function we will avoid adding more
include requirements.

2007-05-31 15:17:33

by Bjorn Helgaas

[permalink] [raw]
Subject: Re: [PATCH 4/5] serial: convert early_uart to earlycon for 8250

On Wednesday 30 May 2007 10:48:59 pm Andrew Morton wrote:
> On Wed, 30 May 2007 21:36:41 -0700 "Yinghai Lu" <[email protected]> wrote:
>
> > On 5/30/07, Yinghai Lu <[email protected]> wrote:
> > > On 5/30/07, Andrew Morton <[email protected]> wrote:
> > > > On Tue, 29 May 2007 18:43:59 -0700 Yinghai Lu <[email protected]> wrote:
> > > >
> > > > > [PATCH 4/5] serial: convert early_uart to earlycon for 8250
> > > >
> > > > drivers/serial/8250_early.c: In function 'parse_options':
> > > > drivers/serial/8250_early.c:143: error: 'FIX_EARLYCON_MEM_BASE' undeclared (first use in this function)
> > > > drivers/serial/8250_early.c:143: error: (Each undeclared identifier is reported only once
> > > >
> > > > That was with http://userweb.kernel.org/~akpm/config-sony.txt, but this is
> > > > going to break a whole pile of architectures (alpha, powerpc, others).
> > >
> > > alpha, powerpc, others may need sth like ia64, if they do not support fixmap.
> >
> > or create dummy fixmap.h that doesn't support fixmap.
>
> You could require that the architecture implement some specific function
> for mapping the early-uart.

We could, but we already have bt_ioremap, dmi_ioremap, and early_ioremap.
Do we really want to proliferate more flavors of "early ioremap"? I'd
rather consolidate the ones we already have.

2007-05-31 16:32:51

by Yinghai Lu

[permalink] [raw]
Subject: Re: [PATCH 4/5] serial: convert early_uart to earlycon for 8250

On 5/31/07, Bjorn Helgaas <[email protected]> wrote:
> On Wednesday 30 May 2007 10:48:59 pm Andrew Morton wrote:
> > You could require that the architecture implement some specific function
> > for mapping the early-uart.
>
> We could, but we already have bt_ioremap, dmi_ioremap, and early_ioremap.
> Do we really want to proliferate more flavors of "early ioremap"? I'd
> rather consolidate the ones we already have.
>
not really.

dhcp-umpk12-63-201:/home/yhlu/xx/xx/kernel/linux-2.6/include # grep
bt_ioremap * -r
asm-i386/dmi.h:#define dmi_ioremap bt_ioremap
asm-i386/io.h: * bt_ioremap() and bt_iounmap() are for temporary early boot-time
asm-i386/io.h:extern void *bt_ioremap(unsigned long offset, unsigned long size);
asm-i386/io.h:#define dmi_ioremap bt_ioremap

dhcp-umpk12-63-201:/home/yhlu/xx/xx/kernel/linux-2.6/include # grep
early_ioremap * -r
asm-x86_64/dmi.h:#define dmi_ioremap early_ioremap
asm-x86_64/io.h:extern void *early_ioremap(unsigned long addr,
unsigned long size);

dhcp-umpk12-63-201:/home/yhlu/xx/xx/kernel/linux-2.6/include # grep
dmi_ioremap * -r
asm-i386/dmi.h:#define dmi_ioremap bt_ioremap
asm-i386/io.h:#define dmi_ioremap bt_ioremap
asm-ia64/io.h:#define dmi_ioremap ioremap
asm-x86_64/dmi.h:extern void *dmi_ioremap(unsigned long addr, unsigned
long size);
asm-x86_64/dmi.h:#define dmi_ioremap early_ioremap

YH

2007-05-31 16:45:48

by Bjorn Helgaas

[permalink] [raw]
Subject: Re: [PATCH 4/5] serial: convert early_uart to earlycon for 8250

On Thursday 31 May 2007 10:32:42 am Yinghai Lu wrote:
> On 5/31/07, Bjorn Helgaas <[email protected]> wrote:
> > On Wednesday 30 May 2007 10:48:59 pm Andrew Morton wrote:
> > > You could require that the architecture implement some specific function
> > > for mapping the early-uart.
> >
> > We could, but we already have bt_ioremap, dmi_ioremap, and early_ioremap.
> > Do we really want to proliferate more flavors of "early ioremap"? I'd
> > rather consolidate the ones we already have.
> >
> not really.

I'm sorry, I don't understand the point you're making.

Andrew's proposal was that we could add early_uart_ioremap to the list of
bt_ioremap and dmi_ioremap.

I'm suggesting that maybe we should make bt_ioremap smart enough that
we could use it for early uart mapping. And maybe we could get rid
of dmi_ioremap, and make DMI use bt_ioremap as well (this would require
some shims for x86_64 and ia64).

> dhcp-umpk12-63-201:/home/yhlu/xx/xx/kernel/linux-2.6/include # grep
> bt_ioremap * -r
> asm-i386/dmi.h:#define dmi_ioremap bt_ioremap
> asm-i386/io.h: * bt_ioremap() and bt_iounmap() are for temporary early boot-time
> asm-i386/io.h:extern void *bt_ioremap(unsigned long offset, unsigned long size);
> asm-i386/io.h:#define dmi_ioremap bt_ioremap
>
> dhcp-umpk12-63-201:/home/yhlu/xx/xx/kernel/linux-2.6/include # grep
> early_ioremap * -r
> asm-x86_64/dmi.h:#define dmi_ioremap early_ioremap
> asm-x86_64/io.h:extern void *early_ioremap(unsigned long addr,
> unsigned long size);
>
> dhcp-umpk12-63-201:/home/yhlu/xx/xx/kernel/linux-2.6/include # grep
> dmi_ioremap * -r
> asm-i386/dmi.h:#define dmi_ioremap bt_ioremap
> asm-i386/io.h:#define dmi_ioremap bt_ioremap
> asm-ia64/io.h:#define dmi_ioremap ioremap
> asm-x86_64/dmi.h:extern void *dmi_ioremap(unsigned long addr, unsigned
> long size);
> asm-x86_64/dmi.h:#define dmi_ioremap early_ioremap

2007-05-31 18:49:16

by Yinghai Lu

[permalink] [raw]
Subject: Re: [PATCH 4/5] serial: convert early_uart to earlycon for 8250

On 5/31/07, Bjorn Helgaas <[email protected]> wrote:
> > not really.
>
> I'm sorry, I don't understand the point you're making.
>
> Andrew's proposal was that we could add early_uart_ioremap to the list of
> bt_ioremap and dmi_ioremap.
>

for i386, bt_ioremap is using fixmap, and it is temporary boot-time
mappings, used before ioremap() is functional.
but we need one as permanent fixed address.

for x86_64, early_ioremap. I'd like to make to static, because
dmi_ioremap could use ioremap instead.

Fix address could make the earlycon can be used more earlier.

YH