diff options
| -rw-r--r-- | arch/i386/kernel/cpu/Makefile | 2 | ||||
| -rw-r--r-- | arch/i386/kernel/cpu/bugs.c | 191 | ||||
| -rw-r--r-- | include/asm-i386/alternative.h | 1 | ||||
| -rw-r--r-- | include/asm-i386/bugs.h | 194 |
4 files changed, 197 insertions, 191 deletions
diff --git a/arch/i386/kernel/cpu/Makefile b/arch/i386/kernel/cpu/Makefile index 010aecfffbc..5fb1a756043 100644 --- a/arch/i386/kernel/cpu/Makefile +++ b/arch/i386/kernel/cpu/Makefile @@ -2,7 +2,7 @@ # Makefile for x86-compatible CPU details and quirks # -obj-y := common.o proc.o +obj-y := common.o proc.o bugs.o obj-y += amd.o obj-y += cyrix.o diff --git a/arch/i386/kernel/cpu/bugs.c b/arch/i386/kernel/cpu/bugs.c new file mode 100644 index 00000000000..54428a2500f --- /dev/null +++ b/arch/i386/kernel/cpu/bugs.c @@ -0,0 +1,191 @@ +/* + * arch/i386/cpu/bugs.c + * + * Copyright (C) 1994 Linus Torvalds + * + * Cyrix stuff, June 1998 by: + * - Rafael R. Reilova (moved everything from head.S), + * <rreilova@ececs.uc.edu> + * - Channing Corn (tests & fixes), + * - Andrew D. Balsa (code cleanup). + */ +#include <linux/init.h> +#include <linux/utsname.h> +#include <asm/processor.h> +#include <asm/i387.h> +#include <asm/msr.h> +#include <asm/paravirt.h> +#include <asm/alternative.h> + +static int __init no_halt(char *s) +{ + boot_cpu_data.hlt_works_ok = 0; + return 1; +} + +__setup("no-hlt", no_halt); + +static int __init mca_pentium(char *s) +{ + mca_pentium_flag = 1; + return 1; +} + +__setup("mca-pentium", mca_pentium); + +static int __init no_387(char *s) +{ + boot_cpu_data.hard_math = 0; + write_cr0(0xE | read_cr0()); + return 1; +} + +__setup("no387", no_387); + +static double __initdata x = 4195835.0; +static double __initdata y = 3145727.0; + +/* + * This used to check for exceptions.. + * However, it turns out that to support that, + * the XMM trap handlers basically had to + * be buggy. So let's have a correct XMM trap + * handler, and forget about printing out + * some status at boot. + * + * We should really only care about bugs here + * anyway. Not features. + */ +static void __init check_fpu(void) +{ + if (!boot_cpu_data.hard_math) { +#ifndef CONFIG_MATH_EMULATION + printk(KERN_EMERG "No coprocessor found and no math emulation present.\n"); + printk(KERN_EMERG "Giving up.\n"); + for (;;) ; +#endif + return; + } + +/* trap_init() enabled FXSR and company _before_ testing for FP problems here. */ + /* Test for the divl bug.. */ + __asm__("fninit\n\t" + "fldl %1\n\t" + "fdivl %2\n\t" + "fmull %2\n\t" + "fldl %1\n\t" + "fsubp %%st,%%st(1)\n\t" + "fistpl %0\n\t" + "fwait\n\t" + "fninit" + : "=m" (*&boot_cpu_data.fdiv_bug) + : "m" (*&x), "m" (*&y)); + if (boot_cpu_data.fdiv_bug) + printk("Hmm, FPU with FDIV bug.\n"); +} + +static void __init check_hlt(void) +{ + if (paravirt_enabled()) + return; + + printk(KERN_INFO "Checking 'hlt' instruction... "); + if (!boot_cpu_data.hlt_works_ok) { + printk("disabled\n"); + return; + } + halt(); + halt(); + halt(); + halt(); + printk("OK.\n"); +} + +/* + * Most 386 processors have a bug where a POPAD can lock the + * machine even from user space. + */ + +static void __init check_popad(void) +{ +#ifndef CONFIG_X86_POPAD_OK + int res, inp = (int) &res; + + printk(KERN_INFO "Checking for popad bug... "); + __asm__ __volatile__( + "movl $12345678,%%eax; movl $0,%%edi; pusha; popa; movl (%%edx,%%edi),%%ecx " + : "=&a" (res) + : "d" (inp) + : "ecx", "edi" ); + /* If this fails, it means that any user program may lock the CPU hard. Too bad. */ + if (res != 12345678) printk( "Buggy.\n" ); + else printk( "OK.\n" ); +#endif +} + +/* + * Check whether we are able to run this kernel safely on SMP. + * + * - In order to run on a i386, we need to be compiled for i386 + * (for due to lack of "invlpg" and working WP on a i386) + * - In order to run on anything without a TSC, we need to be + * compiled for a i486. + * - In order to support the local APIC on a buggy Pentium machine, + * we need to be compiled with CONFIG_X86_GOOD_APIC disabled, + * which happens implicitly if compiled for a Pentium or lower + * (unless an advanced selection of CPU features is used) as an + * otherwise config implies a properly working local APIC without + * the need to do extra reads from the APIC. +*/ + +static void __init check_config(void) +{ +/* + * We'd better not be a i386 if we're configured to use some + * i486+ only features! (WP works in supervisor mode and the + * new "invlpg" and "bswap" instructions) + */ +#if defined(CONFIG_X86_WP_WORKS_OK) || defined(CONFIG_X86_INVLPG) || defined(CONFIG_X86_BSWAP) + if (boot_cpu_data.x86 == 3) + panic("Kernel requires i486+ for 'invlpg' and other features"); +#endif + +/* + * If we configured ourselves for a TSC, we'd better have one! + */ +#ifdef CONFIG_X86_TSC + if (!cpu_has_tsc && !tsc_disable) + panic("Kernel compiled for Pentium+, requires TSC feature!"); +#endif + +/* + * If we were told we had a good local APIC, check for buggy Pentia, + * i.e. all B steppings and the C2 stepping of P54C when using their + * integrated APIC (see 11AP erratum in "Pentium Processor + * Specification Update"). + */ +#if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86_GOOD_APIC) + if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL + && cpu_has_apic + && boot_cpu_data.x86 == 5 + && boot_cpu_data.x86_model == 2 + && (boot_cpu_data.x86_mask < 6 || boot_cpu_data.x86_mask == 11)) + panic("Kernel compiled for PMMX+, assumes a local APIC without the read-before-write bug!"); +#endif +} + + +void __init check_bugs(void) +{ + identify_boot_cpu(); +#ifndef CONFIG_SMP + printk("CPU: "); + print_cpu_info(&boot_cpu_data); +#endif + check_config(); + check_fpu(); + check_hlt(); + check_popad(); + init_utsname()->machine[1] = '0' + (boot_cpu_data.x86 > 6 ? 6 : boot_cpu_data.x86); + alternative_instructions(); +} diff --git a/include/asm-i386/alternative.h b/include/asm-i386/alternative.h index b8fa9557c53..dbc1a29284f 100644 --- a/include/asm-i386/alternative.h +++ b/include/asm-i386/alternative.h @@ -16,6 +16,7 @@ struct alt_instr { u8 pad; }; +extern void alternative_instructions(void); extern void apply_alternatives(struct alt_instr *start, struct alt_instr *end); struct module; diff --git a/include/asm-i386/bugs.h b/include/asm-i386/bugs.h index c90c7c49930..df539b39044 100644 --- a/include/asm-i386/bugs.h +++ b/include/asm-i386/bugs.h @@ -1,198 +1,12 @@ /* - * include/asm-i386/bugs.h - * - * Copyright (C) 1994 Linus Torvalds - * - * Cyrix stuff, June 1998 by: - * - Rafael R. Reilova (moved everything from head.S), - * <rreilova@ececs.uc.edu> - * - Channing Corn (tests & fixes), - * - Andrew D. Balsa (code cleanup). - */ - -/* * This is included by init/main.c to check for architecture-dependent bugs. * * Needs: * void check_bugs(void); */ +#ifndef _ASM_I386_BUG_H +#define _ASM_I386_BUG_H -#include <linux/init.h> -#include <asm/processor.h> -#include <asm/i387.h> -#include <asm/msr.h> -#include <asm/paravirt.h> - -static int __init no_halt(char *s) -{ - boot_cpu_data.hlt_works_ok = 0; - return 1; -} - -__setup("no-hlt", no_halt); - -static int __init mca_pentium(char *s) -{ - mca_pentium_flag = 1; - return 1; -} - -__setup("mca-pentium", mca_pentium); - -static int __init no_387(char *s) -{ - boot_cpu_data.hard_math = 0; - write_cr0(0xE | read_cr0()); - return 1; -} - -__setup("no387", no_387); - -static double __initdata x = 4195835.0; -static double __initdata y = 3145727.0; - -/* - * This used to check for exceptions.. - * However, it turns out that to support that, - * the XMM trap handlers basically had to - * be buggy. So let's have a correct XMM trap - * handler, and forget about printing out - * some status at boot. - * - * We should really only care about bugs here - * anyway. Not features. - */ -static void __init check_fpu(void) -{ - if (!boot_cpu_data.hard_math) { -#ifndef CONFIG_MATH_EMULATION - printk(KERN_EMERG "No coprocessor found and no math emulation present.\n"); - printk(KERN_EMERG "Giving up.\n"); - for (;;) ; -#endif - return; - } - -/* trap_init() enabled FXSR and company _before_ testing for FP problems here. */ - /* Test for the divl bug.. */ - __asm__("fninit\n\t" - "fldl %1\n\t" - "fdivl %2\n\t" - "fmull %2\n\t" - "fldl %1\n\t" - "fsubp %%st,%%st(1)\n\t" - "fistpl %0\n\t" - "fwait\n\t" - "fninit" - : "=m" (*&boot_cpu_data.fdiv_bug) - : "m" (*&x), "m" (*&y)); - if (boot_cpu_data.fdiv_bug) - printk("Hmm, FPU with FDIV bug.\n"); -} - -static void __init check_hlt(void) -{ - if (paravirt_enabled()) - return; - - printk(KERN_INFO "Checking 'hlt' instruction... "); - if (!boot_cpu_data.hlt_works_ok) { - printk("disabled\n"); - return; - } - halt(); - halt(); - halt(); - halt(); - printk("OK.\n"); -} - -/* - * Most 386 processors have a bug where a POPAD can lock the - * machine even from user space. - */ - -static void __init check_popad(void) -{ -#ifndef CONFIG_X86_POPAD_OK - int res, inp = (int) &res; - - printk(KERN_INFO "Checking for popad bug... "); - __asm__ __volatile__( - "movl $12345678,%%eax; movl $0,%%edi; pusha; popa; movl (%%edx,%%edi),%%ecx " - : "=&a" (res) - : "d" (inp) - : "ecx", "edi" ); - /* If this fails, it means that any user program may lock the CPU hard. Too bad. */ - if (res != 12345678) printk( "Buggy.\n" ); - else printk( "OK.\n" ); -#endif -} - -/* - * Check whether we are able to run this kernel safely on SMP. - * - * - In order to run on a i386, we need to be compiled for i386 - * (for due to lack of "invlpg" and working WP on a i386) - * - In order to run on anything without a TSC, we need to be - * compiled for a i486. - * - In order to support the local APIC on a buggy Pentium machine, - * we need to be compiled with CONFIG_X86_GOOD_APIC disabled, - * which happens implicitly if compiled for a Pentium or lower - * (unless an advanced selection of CPU features is used) as an - * otherwise config implies a properly working local APIC without - * the need to do extra reads from the APIC. -*/ - -static void __init check_config(void) -{ -/* - * We'd better not be a i386 if we're configured to use some - * i486+ only features! (WP works in supervisor mode and the - * new "invlpg" and "bswap" instructions) - */ -#if defined(CONFIG_X86_WP_WORKS_OK) || defined(CONFIG_X86_INVLPG) || defined(CONFIG_X86_BSWAP) - if (boot_cpu_data.x86 == 3) - panic("Kernel requires i486+ for 'invlpg' and other features"); -#endif - -/* - * If we configured ourselves for a TSC, we'd better have one! - */ -#ifdef CONFIG_X86_TSC - if (!cpu_has_tsc && !tsc_disable) - panic("Kernel compiled for Pentium+, requires TSC feature!"); -#endif - -/* - * If we were told we had a good local APIC, check for buggy Pentia, - * i.e. all B steppings and the C2 stepping of P54C when using their - * integrated APIC (see 11AP erratum in "Pentium Processor - * Specification Update"). - */ -#if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86_GOOD_APIC) - if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL - && cpu_has_apic - && boot_cpu_data.x86 == 5 - && boot_cpu_data.x86_model == 2 - && (boot_cpu_data.x86_mask < 6 || boot_cpu_data.x86_mask == 11)) - panic("Kernel compiled for PMMX+, assumes a local APIC without the read-before-write bug!"); -#endif -} - -extern void alternative_instructions(void); +extern void __init check_bugs(void); -static void __init check_bugs(void) -{ - identify_cpu(&boot_cpu_data); -#ifndef CONFIG_SMP - printk("CPU: "); - print_cpu_info(&boot_cpu_data); -#endif - check_config(); - check_fpu(); - check_hlt(); - check_popad(); - init_utsname()->machine[1] = '0' + (boot_cpu_data.x86 > 6 ? 6 : boot_cpu_data.x86); - alternative_instructions(); -} +#endif /* _ASM_I386_BUG_H */ |