/* * The earliest FPU detection code. * * Set the X86_FEATURE_FPU CPU-capability bit based on * trying to execute an actual sequence of FPU instructions: */ static void fpu__init_system_early_generic(struct cpuinfo_x86 *c) { unsigned long cr0; u16 fsw, fcw; fsw = fcw = 0xffff; cr0 = read_cr0(); cr0 &= ~(X86_CR0_TS | X86_CR0_EM); write_cr0(cr0); asm volatile("fninit ; fnstsw %0 ; fnstcw %1" : "+m" (fsw), "+m" (fcw)); if (fsw == 0 && (fcw & 0x103f) == 0x003f) set_cpu_cap(c, X86_FEATURE_FPU); else clear_cpu_cap(c, X86_FEATURE_FPU); #ifndef CONFIG_MATH_EMULATION if (!cpu_has_fpu) { pr_emerg("x86/fpu: Giving up, no FPU found and no math emulation present\n"); for (;;) asm volatile("hlt"); }
static void __cpuinit filter_cpuid_features(struct cpuinfo_x86 *c, bool warn) { const struct cpuid_dependent_feature *df; for (df = cpuid_dependent_features; df->feature; df++) { if (!cpu_has(c, df->feature)) continue; /* * Note: cpuid_level is set to -1 if unavailable, but * extended_extended_level is set to 0 if unavailable * and the legitimate extended levels are all negative * when signed; hence the weird messing around with * signs here... */ if (!((s32)df->level < 0 ? (u32)df->level > (u32)c->extended_cpuid_level : (s32)df->level > (s32)c->cpuid_level)) continue; clear_cpu_cap(c, df->feature); if (!warn) continue; printk(KERN_WARNING "CPU: CPU feature %s disabled, no CPUID level 0x%x\n", x86_cap_flags[df->feature], df->level); } }
static void __cpuinit early_init_intel(struct cpuinfo_x86 *c) { /* Unmask CPUID levels if masked: */ if (c->x86 > 6 || (c->x86 == 6 && c->x86_model >= 0xd)) { u64 misc_enable; rdmsrl(MSR_IA32_MISC_ENABLE, misc_enable); if (misc_enable & MSR_IA32_MISC_ENABLE_LIMIT_CPUID) { misc_enable &= ~MSR_IA32_MISC_ENABLE_LIMIT_CPUID; wrmsrl(MSR_IA32_MISC_ENABLE, misc_enable); c->cpuid_level = cpuid_eax(0); } } if ((c->x86 == 0xf && c->x86_model >= 0x03) || (c->x86 == 0x6 && c->x86_model >= 0x0e)) set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC); #ifdef CONFIG_X86_64 set_cpu_cap(c, X86_FEATURE_SYSENTER32); #else /* Netburst reports 64 bytes clflush size, but does IO in 128 bytes */ if (c->x86 == 15 && c->x86_cache_alignment == 64) c->x86_cache_alignment = 128; #endif /* CPUID workaround for 0F33/0F34 CPU */ if (c->x86 == 0xF && c->x86_model == 0x3 && (c->x86_mask == 0x3 || c->x86_mask == 0x4)) c->x86_phys_bits = 36; /* * c->x86_power is 8000_0007 edx. Bit 8 is TSC runs at constant rate * with P/T states and does not stop in deep C-states. * * It is also reliable across cores and sockets. (but not across * cabinets - we turn it off in that case explicitly.) */ if (c->x86_power & (1 << 8)) { set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC); set_cpu_cap(c, X86_FEATURE_NONSTOP_TSC); set_cpu_cap(c, X86_FEATURE_TSC_RELIABLE); sched_clock_stable = 1; } /* * There is a known erratum on Pentium III and Core Solo * and Core Duo CPUs. * " Page with PAT set to WC while associated MTRR is UC * may consolidate to UC " * Because of this erratum, it is better to stick with * setting WC in MTRR rather than using PAT on these CPUs. * * Enable PAT WC only on P4, Core 2 or later CPUs. */ if (c->x86 == 6 && c->x86_model < 15) clear_cpu_cap(c, X86_FEATURE_PAT); }
void __init lguest_arch_host_init(void) { int i; for (i = 0; i < IDT_ENTRIES; i++) default_idt_entries[i] += switcher_offset(); for_each_possible_cpu(i) { struct lguest_pages *pages = lguest_pages(i); struct lguest_ro_state *state = &pages->state; state->host_gdt_desc.size = GDT_SIZE-1; state->host_gdt_desc.address = (long)get_cpu_gdt_table(i); store_idt(&state->host_idt_desc); state->guest_idt_desc.size = sizeof(state->guest_idt)-1; state->guest_idt_desc.address = (long)&state->guest_idt; state->guest_gdt_desc.size = sizeof(state->guest_gdt)-1; state->guest_gdt_desc.address = (long)&state->guest_gdt; state->guest_tss.sp0 = (long)(&pages->regs + 1); state->guest_tss.ss0 = LGUEST_DS; state->guest_tss.io_bitmap_base = sizeof(state->guest_tss); setup_default_gdt_entries(state); setup_default_idt_entries(state, default_idt_entries); get_cpu_gdt_table(i)[GDT_ENTRY_LGUEST_CS] = FULL_EXEC_SEGMENT; get_cpu_gdt_table(i)[GDT_ENTRY_LGUEST_DS] = FULL_SEGMENT; } lguest_entry.offset = (long)switch_to_guest + switcher_offset(); lguest_entry.segment = LGUEST_CS; get_online_cpus(); if (cpu_has_pge) { cpu_had_pge = 1; on_each_cpu(adjust_pge, (void *)0, 1); clear_cpu_cap(&boot_cpu_data, X86_FEATURE_PGE); } put_online_cpus(); }
void x86_init_rdrand(struct cpuinfo_x86 *c) { #ifdef CONFIG_ARCH_RANDOM unsigned long tmp; int i, count, ok; if (!cpu_has(c, X86_FEATURE_RDRAND)) return; /* Nothing to do */ for (count = i = 0; i < RESEED_LOOP; i++) { ok = rdrand_long(&tmp); if (ok) count++; } if (count != RESEED_LOOP) clear_cpu_cap(c, X86_FEATURE_RDRAND); #endif }
static void __cpuinit early_init_intel(struct cpuinfo_x86 *c) { u64 misc_enable; /* Unmask CPUID levels if masked: */ if (c->x86 > 6 || (c->x86 == 6 && c->x86_model >= 0xd)) { rdmsrl(MSR_IA32_MISC_ENABLE, misc_enable); if (misc_enable & MSR_IA32_MISC_ENABLE_LIMIT_CPUID) { misc_enable &= ~MSR_IA32_MISC_ENABLE_LIMIT_CPUID; wrmsrl(MSR_IA32_MISC_ENABLE, misc_enable); c->cpuid_level = cpuid_eax(0); get_cpu_cap(c); } } if ((c->x86 == 0xf && c->x86_model >= 0x03) || (c->x86 == 0x6 && c->x86_model >= 0x0e)) set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC); if (c->x86 >= 6 && !cpu_has(c, X86_FEATURE_IA64)) { unsigned lower_word; wrmsr(MSR_IA32_UCODE_REV, 0, 0); /* Required by the SDM */ sync_core(); rdmsr(MSR_IA32_UCODE_REV, lower_word, c->microcode); } /* * Atom erratum AAE44/AAF40/AAG38/AAH41: * * A race condition between speculative fetches and invalidating * a large page. This is worked around in microcode, but we * need the microcode to have already been loaded... so if it is * not, recommend a BIOS update and disable large pages. */ if (c->x86 == 6 && c->x86_model == 0x1c && c->x86_mask <= 2 && c->microcode < 0x20e) { printk(KERN_WARNING "Atom PSE erratum detected, BIOS microcode update recommended\n"); clear_cpu_cap(c, X86_FEATURE_PSE); } #ifdef CONFIG_X86_64 set_cpu_cap(c, X86_FEATURE_SYSENTER32); #else /* Netburst reports 64 bytes clflush size, but does IO in 128 bytes */ if (c->x86 == 15 && c->x86_cache_alignment == 64) c->x86_cache_alignment = 128; #endif /* CPUID workaround for 0F33/0F34 CPU */ if (c->x86 == 0xF && c->x86_model == 0x3 && (c->x86_mask == 0x3 || c->x86_mask == 0x4)) c->x86_phys_bits = 36; /* * c->x86_power is 8000_0007 edx. Bit 8 is TSC runs at constant rate * with P/T states and does not stop in deep C-states. * * It is also reliable across cores and sockets. (but not across * cabinets - we turn it off in that case explicitly.) */ if (c->x86_power & (1 << 8)) { set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC); set_cpu_cap(c, X86_FEATURE_NONSTOP_TSC); if (!check_tsc_unstable()) sched_clock_stable = 1; } /* * There is a known erratum on Pentium III and Core Solo * and Core Duo CPUs. * " Page with PAT set to WC while associated MTRR is UC * may consolidate to UC " * Because of this erratum, it is better to stick with * setting WC in MTRR rather than using PAT on these CPUs. * * Enable PAT WC only on P4, Core 2 or later CPUs. */ if (c->x86 == 6 && c->x86_model < 15) clear_cpu_cap(c, X86_FEATURE_PAT); #ifdef CONFIG_KMEMCHECK /* * P4s have a "fast strings" feature which causes single- * stepping REP instructions to only generate a #DB on * cache-line boundaries. * * Ingo Molnar reported a Pentium D (model 6) and a Xeon * (model 2) with the same problem. */ if (c->x86 == 15) { rdmsrl(MSR_IA32_MISC_ENABLE, misc_enable); if (misc_enable & MSR_IA32_MISC_ENABLE_FAST_STRING) { printk(KERN_INFO "kmemcheck: Disabling fast string operations\n"); misc_enable &= ~MSR_IA32_MISC_ENABLE_FAST_STRING; wrmsrl(MSR_IA32_MISC_ENABLE, misc_enable); } } #endif /* * If fast string is not enabled in IA32_MISC_ENABLE for any reason, * clear the fast string and enhanced fast string CPU capabilities. */ if (c->x86 > 6 || (c->x86 == 6 && c->x86_model >= 0xd)) { rdmsrl(MSR_IA32_MISC_ENABLE, misc_enable); if (!(misc_enable & MSR_IA32_MISC_ENABLE_FAST_STRING)) { printk(KERN_INFO "Disabled fast string operations\n"); setup_clear_cpu_cap(X86_FEATURE_REP_GOOD); setup_clear_cpu_cap(X86_FEATURE_ERMS); } } }
static void __cpuinit intel_workarounds(struct cpuinfo_x86 *c) { unsigned long lo, hi; #ifdef CONFIG_X86_F00F_BUG /* * All current models of Pentium and Pentium with MMX technology CPUs * have the F0 0F bug, which lets nonprivileged users lock up the * system. * Note that the workaround only should be initialized once... */ c->f00f_bug = 0; if (!paravirt_enabled() && c->x86 == 5) { static int f00f_workaround_enabled; c->f00f_bug = 1; if (!f00f_workaround_enabled) { trap_init_f00f_bug(); printk(KERN_NOTICE "Intel Pentium with F0 0F bug - workaround enabled.\n"); f00f_workaround_enabled = 1; } } #endif /* * SEP CPUID bug: Pentium Pro reports SEP but doesn't have it until * model 3 mask 3 */ if ((c->x86<<8 | c->x86_model<<4 | c->x86_mask) < 0x633) clear_cpu_cap(c, X86_FEATURE_SEP); /* * P4 Xeon errata 037 workaround. * Hardware prefetcher may cause stale data to be loaded into the cache. */ if ((c->x86 == 15) && (c->x86_model == 1) && (c->x86_mask == 1)) { rdmsr(MSR_IA32_MISC_ENABLE, lo, hi); if ((lo & MSR_IA32_MISC_ENABLE_PREFETCH_DISABLE) == 0) { printk (KERN_INFO "CPU: C0 stepping P4 Xeon detected.\n"); printk (KERN_INFO "CPU: Disabling hardware prefetching (Errata 037)\n"); lo |= MSR_IA32_MISC_ENABLE_PREFETCH_DISABLE; wrmsr(MSR_IA32_MISC_ENABLE, lo, hi); } } /* * See if we have a good local APIC by checking 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 (cpu_has_apic && (c->x86<<8 | c->x86_model<<4) == 0x520 && (c->x86_mask < 0x6 || c->x86_mask == 0xb)) set_cpu_cap(c, X86_FEATURE_11AP); #ifdef CONFIG_X86_INTEL_USERCOPY /* * Set up the preferred alignment for movsl bulk memory moves */ switch (c->x86) { case 4: /* 486: untested */ break; case 5: /* Old Pentia: untested */ break; case 6: /* PII/PIII only like movsl with 8-byte alignment */ movsl_mask.mask = 7; break; case 15: /* P4 is OK down to 8-byte alignment */ movsl_mask.mask = 7; break; } #endif #ifdef CONFIG_X86_NUMAQ numaq_tsc_disable(); #endif intel_smp_check(c); }
static void early_init_intel(struct cpuinfo_x86 *c) { u64 misc_enable; /* Unmask CPUID levels if masked: */ if (c->x86 > 6 || (c->x86 == 6 && c->x86_model >= 0xd)) { if (msr_clear_bit(MSR_IA32_MISC_ENABLE, MSR_IA32_MISC_ENABLE_LIMIT_CPUID_BIT) > 0) { c->cpuid_level = cpuid_eax(0); get_cpu_cap(c); } } if ((c->x86 == 0xf && c->x86_model >= 0x03) || (c->x86 == 0x6 && c->x86_model >= 0x0e)) set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC); if (c->x86 >= 6 && !cpu_has(c, X86_FEATURE_IA64)) { unsigned lower_word; wrmsr(MSR_IA32_UCODE_REV, 0, 0); /* Required by the SDM */ sync_core(); rdmsr(MSR_IA32_UCODE_REV, lower_word, c->microcode); } /* * Atom erratum AAE44/AAF40/AAG38/AAH41: * * A race condition between speculative fetches and invalidating * a large page. This is worked around in microcode, but we * need the microcode to have already been loaded... so if it is * not, recommend a BIOS update and disable large pages. */ if (c->x86 == 6 && c->x86_model == 0x1c && c->x86_mask <= 2 && c->microcode < 0x20e) { pr_warn("Atom PSE erratum detected, BIOS microcode update recommended\n"); clear_cpu_cap(c, X86_FEATURE_PSE); } #ifdef CONFIG_X86_64 set_cpu_cap(c, X86_FEATURE_SYSENTER32); #else /* Netburst reports 64 bytes clflush size, but does IO in 128 bytes */ if (c->x86 == 15 && c->x86_cache_alignment == 64) c->x86_cache_alignment = 128; #endif /* CPUID workaround for 0F33/0F34 CPU */ if (c->x86 == 0xF && c->x86_model == 0x3 && (c->x86_mask == 0x3 || c->x86_mask == 0x4)) c->x86_phys_bits = 36; /* * c->x86_power is 8000_0007 edx. Bit 8 is TSC runs at constant rate * with P/T states and does not stop in deep C-states. * * It is also reliable across cores and sockets. (but not across * cabinets - we turn it off in that case explicitly.) */ if (c->x86_power & (1 << 8)) { set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC); set_cpu_cap(c, X86_FEATURE_NONSTOP_TSC); if (!check_tsc_unstable()) set_sched_clock_stable(); } /* Penwell and Cloverview have the TSC which doesn't sleep on S3 */ if (c->x86 == 6) { switch (c->x86_model) { case 0x27: /* Penwell */ case 0x35: /* Cloverview */ case 0x4a: /* Merrifield */ set_cpu_cap(c, X86_FEATURE_NONSTOP_TSC_S3); break; default: break; } } /* * There is a known erratum on Pentium III and Core Solo * and Core Duo CPUs. * " Page with PAT set to WC while associated MTRR is UC * may consolidate to UC " * Because of this erratum, it is better to stick with * setting WC in MTRR rather than using PAT on these CPUs. * * Enable PAT WC only on P4, Core 2 or later CPUs. */ if (c->x86 == 6 && c->x86_model < 15) clear_cpu_cap(c, X86_FEATURE_PAT); #ifdef CONFIG_KMEMCHECK /* * P4s have a "fast strings" feature which causes single- * stepping REP instructions to only generate a #DB on * cache-line boundaries. * * Ingo Molnar reported a Pentium D (model 6) and a Xeon * (model 2) with the same problem. */ if (c->x86 == 15) if (msr_clear_bit(MSR_IA32_MISC_ENABLE, MSR_IA32_MISC_ENABLE_FAST_STRING_BIT) > 0) pr_info("kmemcheck: Disabling fast string operations\n"); #endif /* * If fast string is not enabled in IA32_MISC_ENABLE for any reason, * clear the fast string and enhanced fast string CPU capabilities. */ if (c->x86 > 6 || (c->x86 == 6 && c->x86_model >= 0xd)) { rdmsrl(MSR_IA32_MISC_ENABLE, misc_enable); if (!(misc_enable & MSR_IA32_MISC_ENABLE_FAST_STRING)) { pr_info("Disabled fast string operations\n"); setup_clear_cpu_cap(X86_FEATURE_REP_GOOD); setup_clear_cpu_cap(X86_FEATURE_ERMS); } } /* * Intel Quark Core DevMan_001.pdf section 6.4.11 * "The operating system also is required to invalidate (i.e., flush) * the TLB when any changes are made to any of the page table entries. * The operating system must reload CR3 to cause the TLB to be flushed" * * As a result, boot_cpu_has(X86_FEATURE_PGE) in arch/x86/include/asm/tlbflush.h * should be false so that __flush_tlb_all() causes CR3 insted of CR4.PGE * to be modified. */ if (c->x86 == 5 && c->x86_model == 9) { pr_info("Disabling PGE capability bit\n"); setup_clear_cpu_cap(X86_FEATURE_PGE); } if (c->cpuid_level >= 0x00000001) { u32 eax, ebx, ecx, edx; cpuid(0x00000001, &eax, &ebx, &ecx, &edx); /* * If HTT (EDX[28]) is set EBX[16:23] contain the number of * apicids which are reserved per package. Store the resulting * shift value for the package management code. */ if (edx & (1U << 28)) c->x86_coreid_bits = get_count_order((ebx >> 16) & 0xff); }
/*H:020 * Now the Switcher is mapped and every thing else is ready, we need to do * some more i386-specific initialization. */ void __init lguest_arch_host_init(void) { int i; /* * Most of the x86/switcher_32.S doesn't care that it's been moved; on * Intel, jumps are relative, and it doesn't access any references to * external code or data. * * The only exception is the interrupt handlers in switcher.S: their * addresses are placed in a table (default_idt_entries), so we need to * update the table with the new addresses. switcher_offset() is a * convenience function which returns the distance between the * compiled-in switcher code and the high-mapped copy we just made. */ for (i = 0; i < IDT_ENTRIES; i++) default_idt_entries[i] += switcher_offset(); /* * Set up the Switcher's per-cpu areas. * * Each CPU gets two pages of its own within the high-mapped region * (aka. "struct lguest_pages"). Much of this can be initialized now, * but some depends on what Guest we are running (which is set up in * copy_in_guest_info()). */ for_each_possible_cpu(i) { /* lguest_pages() returns this CPU's two pages. */ struct lguest_pages *pages = lguest_pages(i); /* This is a convenience pointer to make the code neater. */ struct lguest_ro_state *state = &pages->state; /* * The Global Descriptor Table: the Host has a different one * for each CPU. We keep a descriptor for the GDT which says * where it is and how big it is (the size is actually the last * byte, not the size, hence the "-1"). */ state->host_gdt_desc.size = GDT_SIZE-1; state->host_gdt_desc.address = (long)get_cpu_gdt_table(i); /* * All CPUs on the Host use the same Interrupt Descriptor * Table, so we just use store_idt(), which gets this CPU's IDT * descriptor. */ store_idt(&state->host_idt_desc); /* * The descriptors for the Guest's GDT and IDT can be filled * out now, too. We copy the GDT & IDT into ->guest_gdt and * ->guest_idt before actually running the Guest. */ state->guest_idt_desc.size = sizeof(state->guest_idt)-1; state->guest_idt_desc.address = (long)&state->guest_idt; state->guest_gdt_desc.size = sizeof(state->guest_gdt)-1; state->guest_gdt_desc.address = (long)&state->guest_gdt; /* * We know where we want the stack to be when the Guest enters * the Switcher: in pages->regs. The stack grows upwards, so * we start it at the end of that structure. */ state->guest_tss.sp0 = (long)(&pages->regs + 1); /* * And this is the GDT entry to use for the stack: we keep a * couple of special LGUEST entries. */ state->guest_tss.ss0 = LGUEST_DS; /* * x86 can have a finegrained bitmap which indicates what I/O * ports the process can use. We set it to the end of our * structure, meaning "none". */ state->guest_tss.io_bitmap_base = sizeof(state->guest_tss); /* * Some GDT entries are the same across all Guests, so we can * set them up now. */ setup_default_gdt_entries(state); /* Most IDT entries are the same for all Guests, too.*/ setup_default_idt_entries(state, default_idt_entries); /* * The Host needs to be able to use the LGUEST segments on this * CPU, too, so put them in the Host GDT. */ get_cpu_gdt_table(i)[GDT_ENTRY_LGUEST_CS] = FULL_EXEC_SEGMENT; get_cpu_gdt_table(i)[GDT_ENTRY_LGUEST_DS] = FULL_SEGMENT; } /* * In the Switcher, we want the %cs segment register to use the * LGUEST_CS GDT entry: we've put that in the Host and Guest GDTs, so * it will be undisturbed when we switch. To change %cs and jump we * need this structure to feed to Intel's "lcall" instruction. */ lguest_entry.offset = (long)switch_to_guest + switcher_offset(); lguest_entry.segment = LGUEST_CS; /* * Finally, we need to turn off "Page Global Enable". PGE is an * optimization where page table entries are specially marked to show * they never change. The Host kernel marks all the kernel pages this * way because it's always present, even when userspace is running. * * Lguest breaks this: unbeknownst to the rest of the Host kernel, we * switch to the Guest kernel. If you don't disable this on all CPUs, * you'll get really weird bugs that you'll chase for two days. * * I used to turn PGE off every time we switched to the Guest and back * on when we return, but that slowed the Switcher down noticibly. */ /* * We don't need the complexity of CPUs coming and going while we're * doing this. */ get_online_cpus(); if (boot_cpu_has(X86_FEATURE_PGE)) { /* We have a broader idea of "global". */ /* Remember that this was originally set (for cleanup). */ cpu_had_pge = 1; /* * adjust_pge is a helper function which sets or unsets the PGE * bit on its CPU, depending on the argument (0 == unset). */ on_each_cpu(adjust_pge, (void *)0, 1); /* Turn off the feature in the global feature set. */ clear_cpu_cap(&boot_cpu_data, X86_FEATURE_PGE); } put_online_cpus(); }
static void init_centaur(struct cpuinfo_x86 *c) { #ifdef CONFIG_X86_32 char *name; u32 fcr_set = 0; u32 fcr_clr = 0; u32 lo, hi, newlo; u32 aa, bb, cc, dd; /* * Bit 31 in normal CPUID used for nonstandard 3DNow ID; * 3DNow is IDd by bit 31 in extended CPUID (1*32+31) anyway */ clear_cpu_cap(c, 0*32+31); #endif early_init_centaur(c); switch (c->x86) { #ifdef CONFIG_X86_32 case 5: switch (c->x86_model) { case 4: name = "C6"; fcr_set = ECX8|DSMC|EDCTLB|EMMX|ERETSTK; fcr_clr = DPDC; pr_notice("Disabling bugged TSC.\n"); clear_cpu_cap(c, X86_FEATURE_TSC); break; case 8: switch (c->x86_mask) { default: name = "2"; break; case 7 ... 9: name = "2A"; break; case 10 ... 15: name = "2B"; break; } fcr_set = ECX8|DSMC|DTLOCK|EMMX|EBRPRED|ERETSTK| E2MMX|EAMD3D; fcr_clr = DPDC; break; case 9: name = "3"; fcr_set = ECX8|DSMC|DTLOCK|EMMX|EBRPRED|ERETSTK| E2MMX|EAMD3D; fcr_clr = DPDC; break; default: name = "??"; } rdmsr(MSR_IDT_FCR1, lo, hi); newlo = (lo|fcr_set) & (~fcr_clr); if (newlo != lo) { pr_info("Centaur FCR was 0x%X now 0x%X\n", lo, newlo); wrmsr(MSR_IDT_FCR1, newlo, hi); } else { pr_info("Centaur FCR is 0x%X\n", lo); } /* Emulate MTRRs using Centaur's MCR. */ set_cpu_cap(c, X86_FEATURE_CENTAUR_MCR); /* Report CX8 */ set_cpu_cap(c, X86_FEATURE_CX8); /* Set 3DNow! on Winchip 2 and above. */ if (c->x86_model >= 8) set_cpu_cap(c, X86_FEATURE_3DNOW); /* See if we can find out some more. */ if (cpuid_eax(0x80000000) >= 0x80000005) { /* Yes, we can. */ cpuid(0x80000005, &aa, &bb, &cc, &dd); /* Add L1 data and code cache sizes. */ c->x86_cache_size = (cc>>24)+(dd>>24); } sprintf(c->x86_model_id, "WinChip %s", name); break; #endif case 6: init_c3(c); break; }
static __init int setup_disableapic(char *str) { disable_apic = 1; clear_cpu_cap(&boot_cpu_data, X86_FEATURE_APIC); return 0; }
static void intel_workarounds(struct cpuinfo_x86 *c) { #ifdef CONFIG_X86_F00F_BUG /* * All models of Pentium and Pentium with MMX technology CPUs * have the F0 0F bug, which lets nonprivileged users lock up the * system. Announce that the fault handler will be checking for it. * The Quark is also family 5, but does not have the same bug. */ clear_cpu_bug(c, X86_BUG_F00F); if (!paravirt_enabled() && c->x86 == 5 && c->x86_model < 9) { static int f00f_workaround_enabled; set_cpu_bug(c, X86_BUG_F00F); if (!f00f_workaround_enabled) { printk(KERN_NOTICE "Intel Pentium with F0 0F bug - workaround enabled.\n"); f00f_workaround_enabled = 1; } } #endif /* * SEP CPUID bug: Pentium Pro reports SEP but doesn't have it until * model 3 mask 3 */ if ((c->x86<<8 | c->x86_model<<4 | c->x86_mask) < 0x633) clear_cpu_cap(c, X86_FEATURE_SEP); /* * PAE CPUID issue: many Pentium M report no PAE but may have a * functionally usable PAE implementation. * Forcefully enable PAE if kernel parameter "forcepae" is present. */ if (forcepae) { printk(KERN_WARNING "PAE forced!\n"); set_cpu_cap(c, X86_FEATURE_PAE); add_taint(TAINT_CPU_OUT_OF_SPEC, LOCKDEP_NOW_UNRELIABLE); } /* * P4 Xeon errata 037 workaround. * Hardware prefetcher may cause stale data to be loaded into the cache. */ if ((c->x86 == 15) && (c->x86_model == 1) && (c->x86_mask == 1)) { if (msr_set_bit(MSR_IA32_MISC_ENABLE, MSR_IA32_MISC_ENABLE_PREFETCH_DISABLE_BIT) > 0) { pr_info("CPU: C0 stepping P4 Xeon detected.\n"); pr_info("CPU: Disabling hardware prefetching (Errata 037)\n"); } } /* * See if we have a good local APIC by checking 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 (cpu_has_apic && (c->x86<<8 | c->x86_model<<4) == 0x520 && (c->x86_mask < 0x6 || c->x86_mask == 0xb)) set_cpu_bug(c, X86_BUG_11AP); #ifdef CONFIG_X86_INTEL_USERCOPY /* * Set up the preferred alignment for movsl bulk memory moves */ switch (c->x86) { case 4: /* 486: untested */ break; case 5: /* Old Pentia: untested */ break; case 6: /* PII/PIII only like movsl with 8-byte alignment */ movsl_mask.mask = 7; break; case 15: /* P4 is OK down to 8-byte alignment */ movsl_mask.mask = 7; break; } #endif intel_smp_check(c); }