diff options
Diffstat (limited to 'arch/x86/kernel/cpu/bugs.c')
| -rw-r--r-- | arch/x86/kernel/cpu/bugs.c | 125 |
1 files changed, 25 insertions, 100 deletions
diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c index 01a26521239..03445346ee0 100644 --- a/arch/x86/kernel/cpu/bugs.c +++ b/arch/x86/kernel/cpu/bugs.c @@ -17,23 +17,6 @@ #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 no_387(char *s) -{ - boot_cpu_data.hard_math = 0; - write_cr0(X86_CR0_TS | X86_CR0_EM | X86_CR0_MP | read_cr0()); - return 1; -} - -__setup("no387", no_387); - static double __initdata x = 4195835.0; static double __initdata y = 3145727.0; @@ -52,20 +35,13 @@ static void __init check_fpu(void) { s32 fdiv_bug; - 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; - } + kernel_fpu_begin(); /* * trap_init() enabled FXSR and company _before_ testing for FP * problems here. * - * Test for the divl bug.. + * Test for the divl bug: http://en.wikipedia.org/wiki/Fdiv_bug */ __asm__("fninit\n\t" "fldl %1\n\t" @@ -79,91 +55,40 @@ static void __init check_fpu(void) : "=m" (*&fdiv_bug) : "m" (*&x), "m" (*&y)); - boot_cpu_data.fdiv_bug = fdiv_bug; - if (boot_cpu_data.fdiv_bug) - printk(KERN_WARNING "Hmm, FPU with FDIV bug.\n"); -} - -static void __init check_hlt(void) -{ - if (paravirt_enabled()) - return; + kernel_fpu_end(); - printk(KERN_INFO "Checking 'hlt' instruction... "); - if (!boot_cpu_data.hlt_works_ok) { - printk("disabled\n"); - return; + if (fdiv_bug) { + set_cpu_bug(&boot_cpu_data, X86_BUG_FDIV); + pr_warn("Hmm, FPU with FDIV bug\n"); } - halt(); - halt(); - halt(); - halt(); - printk(KERN_CONT "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(KERN_CONT "Buggy.\n"); - else - printk(KERN_CONT "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. - */ - -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 } - void __init check_bugs(void) { identify_boot_cpu(); #ifndef CONFIG_SMP - printk(KERN_INFO "CPU: "); + pr_info("CPU: "); print_cpu_info(&boot_cpu_data); #endif - check_config(); - check_fpu(); - check_hlt(); - check_popad(); + + /* + * Check whether we are able to run this kernel safely on SMP. + * + * - i386 is no longer supported. + * - In order to run on anything without a TSC, we need to be + * compiled for a i486. + */ + if (boot_cpu_data.x86 < 4) + panic("Kernel requires i486+ for 'invlpg' and other features"); + init_utsname()->machine[1] = '0' + (boot_cpu_data.x86 > 6 ? 6 : boot_cpu_data.x86); alternative_instructions(); + + /* + * kernel_fpu_begin/end() in check_fpu() relies on the patched + * alternative instructions. + */ + if (cpu_has_fpu) + check_fpu(); } |
