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 cpuid accessor function that vap...@gentoo.org wrote: https://raw.github.com/linux-test-project/ltp/master/include/ltp_cpuid.h Signed-off-by: Benson Leung <ble...@chromium.org> Signed-off-by: Mike Frysinger <vap...@gentoo.org> --- v4 : Cleaned up checkpatch.pl style errors. Used vapier's newer better cpuid. 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 | 42 ++++++++++++++++++---- 1 file changed, 35 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..4372bd2 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 +130,48 @@ 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) +{ +#if defined(__i386__) || defined(__x86_64__) + unsigned int _eax = info, _ebx, _ecx, _edx; + asm volatile ( +# ifdef __i386__ + "xchg %%ebx, %%esi;" /* save ebx (for PIC) */ + "cpuid;" + "xchg %%esi, %%ebx;" /* restore ebx & pass to caller */ + : "=S" (_ebx), +#else + "cpuid;" + : "=b" (_ebx), +#endif + "+a" (_eax), "=c" (_ecx), "=d" (_edx) + : /* inputs: eax is handled above */ + ); + if (eax) + *eax = _eax; + if (ebx) + *ebx = _ebx; + if (ecx) + *ecx = _ecx; + if (edx) + *edx = _edx; +#endif +} + /* * 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 +179,7 @@ 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 +201,7 @@ 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))) { -- 1.8.1.3 -- 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/
