707fa8ed92
According to Intel RDTSC can be always synchronized with LFENCE on all current CPUs. Implement the necessary CPUID bit for that. It is unclear yet if that is true for all future CPUs too, but if there's another way the kernel can be always updated. Cc: asit.k.mallick@intel.com Signed-off-by: Andi Kleen <ak@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
370 lines
8.7 KiB
C
370 lines
8.7 KiB
C
#include <linux/init.h>
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#include <linux/kernel.h>
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#include <linux/string.h>
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#include <linux/bitops.h>
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#include <linux/smp.h>
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#include <linux/thread_info.h>
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#include <linux/module.h>
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#include <asm/processor.h>
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#include <asm/pgtable.h>
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#include <asm/msr.h>
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#include <asm/uaccess.h>
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#include <asm/ptrace.h>
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#include <asm/ds.h>
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#include "cpu.h"
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#ifdef CONFIG_X86_LOCAL_APIC
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#include <asm/mpspec.h>
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#include <asm/apic.h>
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#include <mach_apic.h>
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#endif
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#ifdef CONFIG_X86_INTEL_USERCOPY
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/*
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* Alignment at which movsl is preferred for bulk memory copies.
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*/
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struct movsl_mask movsl_mask __read_mostly;
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#endif
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void __cpuinit early_intel_workaround(struct cpuinfo_x86 *c)
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{
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if (c->x86_vendor != X86_VENDOR_INTEL)
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return;
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/* Netburst reports 64 bytes clflush size, but does IO in 128 bytes */
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if (c->x86 == 15 && c->x86_cache_alignment == 64)
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c->x86_cache_alignment = 128;
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}
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/*
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* Early probe support logic for ppro memory erratum #50
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*
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* This is called before we do cpu ident work
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*/
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int __cpuinit ppro_with_ram_bug(void)
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{
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/* Uses data from early_cpu_detect now */
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if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL &&
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boot_cpu_data.x86 == 6 &&
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boot_cpu_data.x86_model == 1 &&
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boot_cpu_data.x86_mask < 8) {
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printk(KERN_INFO "Pentium Pro with Errata#50 detected. Taking evasive action.\n");
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return 1;
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}
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return 0;
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}
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/*
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* P4 Xeon errata 037 workaround.
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* Hardware prefetcher may cause stale data to be loaded into the cache.
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*/
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static void __cpuinit Intel_errata_workarounds(struct cpuinfo_x86 *c)
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{
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unsigned long lo, hi;
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if ((c->x86 == 15) && (c->x86_model == 1) && (c->x86_mask == 1)) {
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rdmsr (MSR_IA32_MISC_ENABLE, lo, hi);
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if ((lo & (1<<9)) == 0) {
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printk (KERN_INFO "CPU: C0 stepping P4 Xeon detected.\n");
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printk (KERN_INFO "CPU: Disabling hardware prefetching (Errata 037)\n");
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lo |= (1<<9); /* Disable hw prefetching */
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wrmsr (MSR_IA32_MISC_ENABLE, lo, hi);
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}
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}
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}
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/*
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* find out the number of processor cores on the die
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*/
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static int __cpuinit num_cpu_cores(struct cpuinfo_x86 *c)
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{
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unsigned int eax, ebx, ecx, edx;
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if (c->cpuid_level < 4)
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return 1;
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/* Intel has a non-standard dependency on %ecx for this CPUID level. */
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cpuid_count(4, 0, &eax, &ebx, &ecx, &edx);
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if (eax & 0x1f)
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return ((eax >> 26) + 1);
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else
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return 1;
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}
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#ifdef CONFIG_X86_F00F_BUG
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static void __cpuinit trap_init_f00f_bug(void)
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{
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__set_fixmap(FIX_F00F_IDT, __pa(&idt_table), PAGE_KERNEL_RO);
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/*
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* Update the IDT descriptor and reload the IDT so that
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* it uses the read-only mapped virtual address.
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*/
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idt_descr.address = fix_to_virt(FIX_F00F_IDT);
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load_idt(&idt_descr);
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}
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#endif
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static void __cpuinit init_intel(struct cpuinfo_x86 *c)
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{
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unsigned int l2 = 0;
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char *p = NULL;
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#ifdef CONFIG_X86_F00F_BUG
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/*
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* All current models of Pentium and Pentium with MMX technology CPUs
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* have the F0 0F bug, which lets nonprivileged users lock up the system.
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* Note that the workaround only should be initialized once...
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*/
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c->f00f_bug = 0;
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if (!paravirt_enabled() && c->x86 == 5) {
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static int f00f_workaround_enabled = 0;
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c->f00f_bug = 1;
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if ( !f00f_workaround_enabled ) {
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trap_init_f00f_bug();
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printk(KERN_NOTICE "Intel Pentium with F0 0F bug - workaround enabled.\n");
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f00f_workaround_enabled = 1;
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}
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}
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#endif
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select_idle_routine(c);
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l2 = init_intel_cacheinfo(c);
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if (c->cpuid_level > 9 ) {
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unsigned eax = cpuid_eax(10);
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/* Check for version and the number of counters */
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if ((eax & 0xff) && (((eax>>8) & 0xff) > 1))
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set_bit(X86_FEATURE_ARCH_PERFMON, c->x86_capability);
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}
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/* SEP CPUID bug: Pentium Pro reports SEP but doesn't have it until model 3 mask 3 */
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if ((c->x86<<8 | c->x86_model<<4 | c->x86_mask) < 0x633)
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clear_bit(X86_FEATURE_SEP, c->x86_capability);
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/* Names for the Pentium II/Celeron processors
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detectable only by also checking the cache size.
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Dixon is NOT a Celeron. */
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if (c->x86 == 6) {
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switch (c->x86_model) {
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case 5:
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if (c->x86_mask == 0) {
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if (l2 == 0)
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p = "Celeron (Covington)";
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else if (l2 == 256)
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p = "Mobile Pentium II (Dixon)";
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}
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break;
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case 6:
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if (l2 == 128)
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p = "Celeron (Mendocino)";
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else if (c->x86_mask == 0 || c->x86_mask == 5)
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p = "Celeron-A";
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break;
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case 8:
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if (l2 == 128)
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p = "Celeron (Coppermine)";
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break;
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}
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}
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if ( p )
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strcpy(c->x86_model_id, p);
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c->x86_max_cores = num_cpu_cores(c);
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detect_ht(c);
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/* Work around errata */
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Intel_errata_workarounds(c);
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#ifdef CONFIG_X86_INTEL_USERCOPY
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/*
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* Set up the preferred alignment for movsl bulk memory moves
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*/
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switch (c->x86) {
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case 4: /* 486: untested */
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break;
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case 5: /* Old Pentia: untested */
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break;
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case 6: /* PII/PIII only like movsl with 8-byte alignment */
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movsl_mask.mask = 7;
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break;
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case 15: /* P4 is OK down to 8-byte alignment */
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movsl_mask.mask = 7;
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break;
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}
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#endif
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if (cpu_has_xmm)
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set_bit(X86_FEATURE_LFENCE_RDTSC, c->x86_capability);
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if (c->x86 == 15) {
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set_bit(X86_FEATURE_P4, c->x86_capability);
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}
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if (c->x86 == 6)
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set_bit(X86_FEATURE_P3, c->x86_capability);
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if ((c->x86 == 0xf && c->x86_model >= 0x03) ||
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(c->x86 == 0x6 && c->x86_model >= 0x0e))
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set_bit(X86_FEATURE_CONSTANT_TSC, c->x86_capability);
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if (cpu_has_ds) {
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unsigned int l1;
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rdmsr(MSR_IA32_MISC_ENABLE, l1, l2);
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if (!(l1 & (1<<11)))
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set_bit(X86_FEATURE_BTS, c->x86_capability);
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if (!(l1 & (1<<12)))
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set_bit(X86_FEATURE_PEBS, c->x86_capability);
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}
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if (cpu_has_bts)
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ds_init_intel(c);
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}
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static unsigned int __cpuinit intel_size_cache(struct cpuinfo_x86 * c, unsigned int size)
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{
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/* Intel PIII Tualatin. This comes in two flavours.
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* One has 256kb of cache, the other 512. We have no way
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* to determine which, so we use a boottime override
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* for the 512kb model, and assume 256 otherwise.
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*/
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if ((c->x86 == 6) && (c->x86_model == 11) && (size == 0))
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size = 256;
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return size;
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}
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static struct cpu_dev intel_cpu_dev __cpuinitdata = {
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.c_vendor = "Intel",
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.c_ident = { "GenuineIntel" },
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.c_models = {
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{ .vendor = X86_VENDOR_INTEL, .family = 4, .model_names =
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{
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[0] = "486 DX-25/33",
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[1] = "486 DX-50",
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[2] = "486 SX",
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[3] = "486 DX/2",
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[4] = "486 SL",
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[5] = "486 SX/2",
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[7] = "486 DX/2-WB",
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[8] = "486 DX/4",
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[9] = "486 DX/4-WB"
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}
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},
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{ .vendor = X86_VENDOR_INTEL, .family = 5, .model_names =
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{
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[0] = "Pentium 60/66 A-step",
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[1] = "Pentium 60/66",
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[2] = "Pentium 75 - 200",
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[3] = "OverDrive PODP5V83",
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[4] = "Pentium MMX",
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[7] = "Mobile Pentium 75 - 200",
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[8] = "Mobile Pentium MMX"
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}
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},
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{ .vendor = X86_VENDOR_INTEL, .family = 6, .model_names =
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{
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[0] = "Pentium Pro A-step",
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[1] = "Pentium Pro",
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[3] = "Pentium II (Klamath)",
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[4] = "Pentium II (Deschutes)",
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[5] = "Pentium II (Deschutes)",
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[6] = "Mobile Pentium II",
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[7] = "Pentium III (Katmai)",
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[8] = "Pentium III (Coppermine)",
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[10] = "Pentium III (Cascades)",
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[11] = "Pentium III (Tualatin)",
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}
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},
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{ .vendor = X86_VENDOR_INTEL, .family = 15, .model_names =
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{
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[0] = "Pentium 4 (Unknown)",
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[1] = "Pentium 4 (Willamette)",
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[2] = "Pentium 4 (Northwood)",
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[4] = "Pentium 4 (Foster)",
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[5] = "Pentium 4 (Foster)",
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}
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},
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},
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.c_init = init_intel,
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.c_size_cache = intel_size_cache,
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};
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__init int intel_cpu_init(void)
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{
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cpu_devs[X86_VENDOR_INTEL] = &intel_cpu_dev;
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return 0;
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}
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#ifndef CONFIG_X86_CMPXCHG
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unsigned long cmpxchg_386_u8(volatile void *ptr, u8 old, u8 new)
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{
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u8 prev;
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unsigned long flags;
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/* Poor man's cmpxchg for 386. Unsuitable for SMP */
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local_irq_save(flags);
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prev = *(u8 *)ptr;
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if (prev == old)
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*(u8 *)ptr = new;
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local_irq_restore(flags);
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return prev;
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}
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EXPORT_SYMBOL(cmpxchg_386_u8);
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unsigned long cmpxchg_386_u16(volatile void *ptr, u16 old, u16 new)
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{
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u16 prev;
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unsigned long flags;
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/* Poor man's cmpxchg for 386. Unsuitable for SMP */
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local_irq_save(flags);
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prev = *(u16 *)ptr;
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if (prev == old)
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*(u16 *)ptr = new;
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local_irq_restore(flags);
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return prev;
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}
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EXPORT_SYMBOL(cmpxchg_386_u16);
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unsigned long cmpxchg_386_u32(volatile void *ptr, u32 old, u32 new)
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{
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u32 prev;
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unsigned long flags;
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/* Poor man's cmpxchg for 386. Unsuitable for SMP */
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local_irq_save(flags);
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prev = *(u32 *)ptr;
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if (prev == old)
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*(u32 *)ptr = new;
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local_irq_restore(flags);
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return prev;
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}
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EXPORT_SYMBOL(cmpxchg_386_u32);
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#endif
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#ifndef CONFIG_X86_CMPXCHG64
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unsigned long long cmpxchg_486_u64(volatile void *ptr, u64 old, u64 new)
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{
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u64 prev;
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unsigned long flags;
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/* Poor man's cmpxchg8b for 386 and 486. Unsuitable for SMP */
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local_irq_save(flags);
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prev = *(u64 *)ptr;
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if (prev == old)
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*(u64 *)ptr = new;
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local_irq_restore(flags);
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return prev;
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}
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EXPORT_SYMBOL(cmpxchg_486_u64);
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#endif
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// arch_initcall(intel_cpu_init);
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