diff options
Diffstat (limited to 'arch/x86/kernel/cpu/intel.c')
| -rw-r--r-- | arch/x86/kernel/cpu/intel.c | 30 |
1 files changed, 15 insertions, 15 deletions
diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c index 4cbb2e69bea1..0570d4d86006 100644 --- a/arch/x86/kernel/cpu/intel.c +++ b/arch/x86/kernel/cpu/intel.c @@ -6,6 +6,7 @@ #include <linux/minmax.h> #include <linux/smp.h> #include <linux/string.h> +#include <linux/types.h> #ifdef CONFIG_X86_64 #include <linux/topology.h> @@ -777,28 +778,27 @@ static void intel_tlb_lookup(const unsigned char desc) static void intel_detect_tlb(struct cpuinfo_x86 *c) { - int i, j, n; - unsigned int regs[4]; - unsigned char *desc = (unsigned char *)regs; + u32 regs[4]; + u8 *desc = (u8 *)regs; if (c->cpuid_level < 2) return; - /* Number of times to iterate */ - n = cpuid_eax(2) & 0xFF; + cpuid(2, ®s[0], ®s[1], ®s[2], ®s[3]); - for (i = 0 ; i < n ; i++) { - cpuid(2, ®s[0], ®s[1], ®s[2], ®s[3]); - - /* If bit 31 is set, this is an unknown format */ - for (j = 0 ; j < 4 ; j++) - if (regs[j] & (1 << 31)) - regs[j] = 0; + /* Intel CPUs must report an iteration count of 1 */ + if (desc[0] != 0x01) + return; - /* Byte 0 is level count, not a descriptor */ - for (j = 1 ; j < 16 ; j++) - intel_tlb_lookup(desc[j]); + /* If a register's bit 31 is set, it is an unknown format */ + for (int i = 0; i < 4; i++) { + if (regs[i] & (1 << 31)) + regs[i] = 0; } + + /* Skip the first byte as it is not a descriptor */ + for (int i = 1; i < 16; i++) + intel_tlb_lookup(desc[i]); } static const struct cpu_dev intel_cpu_dev = { |