From: Manfred Spraul DEBUG_PAGEALLOC switches to nopentium mode: otherwise a change_page_attr could cause a split of a 4 MB page, which could cause a gfp which might deadlock. Two parts of the cpu initialization cannot be done early: the f00f bug workaround needs a working paging setup, and loops_per_jiffies is only initialized after the timer is running. And everything in setup_arch instead of before start_kernel: The first printk line should be the "Linux verion xy" line from start_kernel. --- 25-akpm/arch/i386/kernel/cpu/common.c | 40 ++++++++++++++++++++++------------ 25-akpm/arch/i386/kernel/setup.c | 3 -- 25-akpm/include/asm-i386/processor.h | 2 - 3 files changed, 29 insertions(+), 16 deletions(-) diff -puN arch/i386/kernel/cpu/common.c~early-x86-cpu-detection-fix arch/i386/kernel/cpu/common.c --- 25/arch/i386/kernel/cpu/common.c~early-x86-cpu-detection-fix 2004-03-15 11:36:05.144371392 -0800 +++ 25-akpm/arch/i386/kernel/cpu/common.c 2004-03-15 11:36:05.149370632 -0800 @@ -234,7 +234,7 @@ void __init generic_identify(struct cpui if ( (xlvl & 0xffff0000) == 0x80000000 ) { if ( xlvl >= 0x80000001 ) c->x86_capability[1] = cpuid_edx(0x80000001); - if ( xlvl >= 0x80000004) + if ( xlvl >= 0x80000004 ) get_model_name(c); /* Default name */ } } @@ -263,18 +263,22 @@ static int __init x86_serial_nr_setup(ch } __setup("serialnumber", x86_serial_nr_setup); -void __init early_identify_cpu(struct cpuinfo_x86 *c) +/* + * This does the hard work of actually picking apart the CPU stuff... + */ +void __init identify_cpu(struct cpuinfo_x86 *c) { - c->loops_per_jiffy = loops_per_jiffy; + int i; + c->x86_cache_size = -1; c->x86_vendor = X86_VENDOR_UNKNOWN; c->cpuid_level = -1; /* CPUID not detected */ c->x86_model = c->x86_mask = 0; /* So far unknown... */ c->x86_vendor_id[0] = '\0'; /* Unset */ c->x86_model_id[0] = '\0'; /* Unset */ - c->x86_clflush_size = 32; memset(&c->x86_capability, 0, sizeof c->x86_capability); + c->x86_clflush_size = 0; if (!have_cpuid_p()) { /* First of all, decide if this is a 486 or higher */ /* It's a 486 if we can modify the AC flag */ @@ -285,16 +289,14 @@ void __init early_identify_cpu(struct cp } generic_identify(c); -} - -/* - * This does the hard work of actually picking apart the CPU stuff... - */ -void __init identify_cpu(struct cpuinfo_x86 *c) -{ - int i; - early_identify_cpu(c); + if (!c->x86_clflush_size) { + /* No cache line size autodetected - manual estimate: */ + if (c->x86 <= 4) + c->x86_clflush_size = 16; + else + c->x86_clflush_size = 32; + } printk(KERN_DEBUG "CPU: After generic identify, caps: %08lx %08lx %08lx %08lx\n", c->x86_capability[0], @@ -382,7 +384,19 @@ void __init identify_cpu(struct cpuinfo_ #ifdef CONFIG_X86_MCE mcheck_init(c); #endif + late_identify_cpu(c); +} + +void __init late_identify_cpu(struct cpuinfo_x86 *c) +{ + /* + * The timer is not yet running when identify cpu is called for the + * first cpu - check_bugs() calls late_identify_cpu and transfers + * loops_per_jiffy from calibrate_delay into the cpu data area. + */ + c->loops_per_jiffy = loops_per_jiffy; } + /* * Perform early boot up checks for a valid TSC. See arch/i386/kernel/time.c */ diff -puN arch/i386/kernel/setup.c~early-x86-cpu-detection-fix arch/i386/kernel/setup.c --- 25/arch/i386/kernel/setup.c~early-x86-cpu-detection-fix 2004-03-15 11:36:05.145371240 -0800 +++ 25-akpm/arch/i386/kernel/setup.c 2004-03-15 11:36:05.150370480 -0800 @@ -1124,6 +1124,7 @@ void __init setup_arch(char **cmdline_p) max_low_pfn = setup_memory(); + identify_cpu(&boot_cpu_data); /* * NOTE: before this point _nobody_ is allowed to allocate * any memory using the bootmem allocator. @@ -1149,8 +1150,6 @@ void __init setup_arch(char **cmdline_p) dmi_scan_machine(); - early_identify_cpu(&boot_cpu_data); - #ifdef CONFIG_X86_GENERICARCH generic_apic_probe(*cmdline_p); #endif diff -puN include/asm-i386/processor.h~early-x86-cpu-detection-fix include/asm-i386/processor.h --- 25/include/asm-i386/processor.h~early-x86-cpu-detection-fix 2004-03-15 11:36:05.147370936 -0800 +++ 25-akpm/include/asm-i386/processor.h 2004-03-15 11:36:05.151370328 -0800 @@ -98,6 +98,7 @@ extern struct cpuinfo_x86 cpu_data[]; extern char ignore_fpu_irq; extern void identify_cpu(struct cpuinfo_x86 *); +extern void late_identify_cpu(struct cpuinfo_x86 *c); extern void print_cpu_info(struct cpuinfo_x86 *); extern void dodgy_tsc(void); @@ -653,6 +654,5 @@ extern void select_idle_routine(const st #endif #define cache_line_size() (boot_cpu_data.x86_clflush_size) -extern void early_identify_cpu(struct cpuinfo_x86 *c); #endif /* __ASM_I386_PROCESSOR_H */ _