diff options
| -rw-r--r-- | Documentation/kernel-parameters.txt | 12 | ||||
| -rw-r--r-- | arch/x86/Kconfig.debug | 79 | ||||
| -rw-r--r-- | arch/x86/kernel/io_delay.c | 106 | ||||
| -rw-r--r-- | include/asm-x86/io_32.h | 10 | ||||
| -rw-r--r-- | include/asm-x86/io_64.h | 10 | ||||
| -rw-r--r-- | kernel/sysctl.c | 9 |
6 files changed, 143 insertions, 83 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 9e60560..b427b7c 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -795,12 +795,14 @@ and is between 256 and 4096 characters. It is defined in the file then look in the higher range. io_delay= [X86-32,X86-64] I/O delay method - standard - Standard port 0x80 delay - alternate - Alternate port 0xed delay + 0x80 + Standard port 0x80 based delay + 0xed + Alternate port 0xed based delay (needed on some systems) udelay - Simple two microsecond delay + Simple two microseconds delay + none + No delay io7= [HW] IO7 for Marvel based alpha systems See comment before marvel_specify_io7 in diff --git a/arch/x86/Kconfig.debug b/arch/x86/Kconfig.debug index 40aba67..77eda46 100644 --- a/arch/x86/Kconfig.debug +++ b/arch/x86/Kconfig.debug @@ -112,13 +112,78 @@ config IOMMU_LEAK Add a simple leak tracer to the IOMMU code. This is useful when you are debugging a buggy device driver that leaks IOMMU mappings. -config UDELAY_IO_DELAY - bool "Delay I/O through udelay instead of outb" - depends on DEBUG_KERNEL +# +# IO delay types: +# + +config IO_DELAY_TYPE_0X80 + int + default "0" + +config IO_DELAY_TYPE_0XED + int + default "1" + +config IO_DELAY_TYPE_UDELAY + int + default "2" + +config IO_DELAY_TYPE_NONE + int + default "3" + +choice + prompt "IO delay type" + default IO_DELAY_0X80 + +config IO_DELAY_0X80 + bool "port 0x80 based port-IO delay [recommended]" + help + This is the traditional Linux IO delay used for in/out_p. + It is the most tested hence safest selection here. + +config IO_DELAY_0XED + bool "port 0xed based port-IO delay" + help + Use port 0xed as the IO delay. This frees up port 0x80 which is + often used as a hardware-debug port. + +config IO_DELAY_UDELAY + bool "udelay based port-IO delay" + help + Use udelay(2) as the IO delay method. This provides the delay + while not having any side-effect on the IO port space. + +config IO_DELAY_NONE + bool "no port-IO delay" help - Make inb_p/outb_p use udelay() based delays by default. Please note - that udelay() does not have the same bus-level side-effects that - the normal outb based delay does meaning this could cause drivers - to change behaviour and/or bugs to surface. + No port-IO delay. Will break on old boxes that require port-IO + delay for certain operations. Should work on most new machines. + +endchoice + +if IO_DELAY_0X80 +config DEFAULT_IO_DELAY_TYPE + int + default IO_DELAY_TYPE_0X80 +endif + +if IO_DELAY_0XED +config DEFAULT_IO_DELAY_TYPE + int + default IO_DELAY_TYPE_0XED +endif + +if IO_DELAY_UDELAY +config DEFAULT_IO_DELAY_TYPE + int + default IO_DELAY_TYPE_UDELAY +endif + +if IO_DELAY_NONE +config DEFAULT_IO_DELAY_TYPE + int + default IO_DELAY_TYPE_NONE +endif endmenu diff --git a/arch/x86/kernel/io_delay.c b/arch/x86/kernel/io_delay.c index 4d955e7..f052e34 100644 --- a/arch/x86/kernel/io_delay.c +++ b/arch/x86/kernel/io_delay.c @@ -1,5 +1,9 @@ /* * I/O delay strategies for inb_p/outb_p + * + * Allow for a DMI based override of port 0x80, needed for certain HP laptops + * and possibly other systems. Also allow for the gradual elimination of + * outb_p/inb_p API uses. */ #include <linux/kernel.h> #include <linux/module.h> @@ -8,98 +12,86 @@ #include <linux/dmi.h> #include <asm/io.h> -/* - * Allow for a DMI based override of port 0x80 needed for certain HP laptops - */ -#define IO_DELAY_PORT_STD 0x80 -#define IO_DELAY_PORT_ALT 0xed - -static void standard_io_delay(void) -{ - asm volatile ("outb %%al, %0" : : "N" (IO_DELAY_PORT_STD)); -} - -static void alternate_io_delay(void) -{ - asm volatile ("outb %%al, %0" : : "N" (IO_DELAY_PORT_ALT)); -} - -/* - * 2 usecs is an upper-bound for the outb delay but note that udelay doesn't - * have the bus-level side-effects that outb does - */ -#define IO_DELAY_USECS 2 - -/* - * High on a hill was a lonely goatherd - */ -static void udelay_io_delay(void) -{ - udelay(IO_DELAY_USECS); -} +int io_delay_type __read_mostly = CONFIG_DEFAULT_IO_DELAY_TYPE; +EXPORT_SYMBOL_GPL(io_delay_type); -#ifndef CONFIG_UDELAY_IO_DELAY -static void (*io_delay)(void) = standard_io_delay; -#else -static void (*io_delay)(void) = udelay_io_delay; -#endif +static int __initdata io_delay_override; /* * Paravirt wants native_io_delay to be a constant. */ void native_io_delay(void) { - io_delay(); + switch (io_delay_type) { + default: + case CONFIG_IO_DELAY_TYPE_0X80: + asm volatile ("outb %al, $0x80"); + break; + case CONFIG_IO_DELAY_TYPE_0XED: + asm volatile ("outb %al, $0xed"); + break; + case CONFIG_IO_DELAY_TYPE_UDELAY: + /* + * 2 usecs is an upper-bound for the outb delay but + * note that udelay doesn't have the bus-level + * side-effects that outb does, nor does udelay() have + * precise timings during very early bootup (the delays + * are shorter until calibrated): + */ + udelay(2); + case CONFIG_IO_DELAY_TYPE_NONE: + break; + } } EXPORT_SYMBOL(native_io_delay); -#ifndef CONFIG_UDELAY_IO_DELAY -static int __init dmi_alternate_io_delay_port(const struct dmi_system_id *id) +static int __init dmi_io_delay_0xed_port(const struct dmi_system_id *id) { - printk(KERN_NOTICE "%s: using alternate I/O delay port\n", id->ident); - io_delay = alternate_io_delay; + if (io_delay_type == CONFIG_IO_DELAY_TYPE_0X80) { + printk(KERN_NOTICE "%s: using 0xed I/O delay port\n", + id->ident); + io_delay_type = CONFIG_IO_DELAY_TYPE_0XED; + } + return 0; } -static struct dmi_system_id __initdata alternate_io_delay_port_dmi_table[] = { +/* + * Quirk table for systems that misbehave (lock up, etc.) if port + * 0x80 is used: + */ +static struct dmi_system_id __initdata io_delay_0xed_port_dmi_table[] = { { - .callback = dmi_alternate_io_delay_port, + .callback = dmi_io_delay_0xed_port, .ident = "HP Pavilion dv9000z", .matches = { DMI_MATCH(DMI_BOARD_VENDOR, "Quanta"), DMI_MATCH(DMI_BOARD_NAME, "30B9") } }, - { - } + { } }; -static int __initdata io_delay_override; - void __init io_delay_init(void) { if (!io_delay_override) - dmi_check_system(alternate_io_delay_port_dmi_table); + dmi_check_system(io_delay_0xed_port_dmi_table); } -#endif static int __init io_delay_param(char *s) { - if (!s) - return -EINVAL; - - if (!strcmp(s, "standard")) - io_delay = standard_io_delay; - else if (!strcmp(s, "alternate")) - io_delay = alternate_io_delay; + if (!strcmp(s, "0x80")) + io_delay_type = CONFIG_IO_DELAY_TYPE_0X80; + else if (!strcmp(s, "0xed")) + io_delay_type = CONFIG_IO_DELAY_TYPE_0XED; else if (!strcmp(s, "udelay")) - io_delay = udelay_io_delay; + io_delay_type = CONFIG_IO_DELAY_TYPE_UDELAY; + else if (!strcmp(s, "none")) + io_delay_type = CONFIG_IO_DELAY_TYPE_NONE; else return -EINVAL; -#ifndef CONFIG_UDELAY_IO_DELAY io_delay_override = 1; -#endif return 0; } diff --git a/include/asm-x86/io_32.h b/include/asm-x86/io_32.h index a8d25c3..2a04bd1 100644 --- a/include/asm-x86/io_32.h +++ b/include/asm-x86/io_32.h @@ -250,15 +250,11 @@ static inline void flush_write_buffers(void) #endif /* __KERNEL__ */ -#ifndef CONFIG_UDELAY_IO_DELAY -extern void io_delay_init(void); -#else -static inline void io_delay_init(void) -{ -} -#endif extern void native_io_delay(void); +extern int io_delay_type; +extern void io_delay_init(void); + #if defined(CONFIG_PARAVIRT) #include <asm/paravirt.h> #else diff --git a/include/asm-x86/io_64.h b/include/asm-x86/io_64.h index 5bebaf9..dbcc03a 100644 --- a/include/asm-x86/io_64.h +++ b/include/asm-x86/io_64.h @@ -35,15 +35,11 @@ * - Arnaldo Carvalho de Melo <acme@conectiva.com.br> */ -#ifndef CONFIG_UDELAY_IO_DELAY -extern void io_delay_init(void); -#else -static inline void io_delay_init(void) -{ -} -#endif extern void native_io_delay(void); +extern int io_delay_type; +extern void io_delay_init(void); + static inline void slow_down_io(void) { native_io_delay(); diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 4bc8e48..357b68b 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -53,6 +53,7 @@ #ifdef CONFIG_X86 #include <asm/nmi.h> #include <asm/stacktrace.h> +#include <asm/io.h> #endif static int deprecated_sysctl_warning(struct __sysctl_args *args); @@ -727,6 +728,14 @@ static struct ctl_table kern_table[] = { .mode = 0644, .proc_handler = &proc_dointvec, }, + { + .ctl_name = CTL_UNNUMBERED, + .procname = "io_delay_type", + .data = &io_delay_type, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = &proc_dointvec, + }, #endif #if defined(CONFIG_MMU) { |
