x86_energy_perf_policy reads cpuid using the cpuid instruction. On i686, when building with PIC, this clobbers ebx, the PIC register.
Fixed using the same cpuid accessor function that vap...@gentoo.org created for i7z: http://code.google.com/p/i7z/issues/detail?id=31 Signed-off-by: Benson Leung <ble...@chromium.org> Signed-off-by: Mike Frysinger <vap...@gentoo.org> --- v3 : No changes. v2 : make cpuid static inline. Remove unused eax from validate_cpuid and clean up return variables from cpuid(). --- .../x86_energy_perf_policy.c | 30 +++++++++++++++++----- 1 file changed, 23 insertions(+), 7 deletions(-) diff --git a/tools/power/x86/x86_energy_perf_policy/x86_energy_perf_policy.c b/tools/power/x86/x86_energy_perf_policy/x86_energy_perf_policy.c index 40b3e54..f8f4e63 100644 --- a/tools/power/x86/x86_energy_perf_policy/x86_energy_perf_policy.c +++ b/tools/power/x86/x86_energy_perf_policy/x86_energy_perf_policy.c @@ -130,20 +130,36 @@ void cmdline(int argc, char **argv) } } +static inline void cpuid(unsigned int info, unsigned int *eax, + unsigned int *ebx, unsigned int *ecx, + unsigned int *edx) +{ + unsigned int _eax = info, _ebx, _ecx, _edx; + asm volatile ("mov %%ebx, %%edi;" /* save ebx (for PIC) */ + "cpuid;" + "mov %%ebx, %%esi;" /* pass to caller */ + "mov %%edi, %%ebx;" /* restore ebx */ + :"+a" (_eax), "=S" (_ebx), "=c" (_ecx), "=d" (_edx) + : /* inputs: eax is handled above */ + :"edi" /* clobbers: we hit edi directly */); + if (eax) *eax = _eax; + if (ebx) *ebx = _ebx; + if (ecx) *ecx = _ecx; + if (edx) *edx = _edx; +} + /* * validate_cpuid() * returns on success, quietly exits on failure (make verbose with -v) */ void validate_cpuid(void) { - unsigned int eax, ebx, ecx, edx, max_level; + unsigned int ebx, ecx, edx, max_level; unsigned int fms, family, model, stepping; - eax = ebx = ecx = edx = 0; - - asm("cpuid" : "=a" (max_level), "=b" (ebx), "=c" (ecx), - "=d" (edx) : "a" (0)); + ebx = ecx = edx = 0; + cpuid(0, &max_level, &ebx, &ecx, &edx); if (ebx != 0x756e6547 || edx != 0x49656e69 || ecx != 0x6c65746e) { if (verbose) fprintf(stderr, "%.4s%.4s%.4s != GenuineIntel", @@ -151,7 +167,7 @@ void validate_cpuid(void) exit(1); } - asm("cpuid" : "=a" (fms), "=c" (ecx), "=d" (edx) : "a" (1) : "ebx"); + cpuid(1, &fms, NULL, NULL, &edx); family = (fms >> 8) & 0xf; model = (fms >> 4) & 0xf; stepping = fms & 0xf; @@ -173,7 +189,7 @@ void validate_cpuid(void) * Support for MSR_IA32_ENERGY_PERF_BIAS * is indicated by CPUID.06H.ECX.bit3 */ - asm("cpuid" : "=a" (eax), "=b" (ebx), "=c" (ecx), "=d" (edx) : "a" (6)); + cpuid(6, NULL, NULL, &ecx, NULL); if (verbose) printf("CPUID.06H.ECX: 0x%x\n", ecx); if (!(ecx & (1 << 3))) { -- 1.8.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
