Messages in this thread Patch in this message | | | From | Benson Leung <> | Subject | [PATCH] tools/power x86_energy_perf_policy: fix cpuid for i686 | Date | Tue, 21 Feb 2012 19:15:21 -0800 |
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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 vapier@chromium.org created for i7z: http://code.google.com/p/i7z/issues/detail?id=31
Signed-off-by: Benson Leung <bleung@chromium.org> --- .../x86_energy_perf_policy.c | 25 ++++++++++++++++---- 1 files changed, 20 insertions(+), 5 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 33c5c7e..576fbf4 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 @@ -130,6 +130,23 @@ void cmdline(int argc, char **argv) } } +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) @@ -141,9 +158,7 @@ void validate_cpuid(void) eax = ebx = ecx = edx = 0; - asm("cpuid" : "=a" (max_level), "=b" (ebx), "=c" (ecx), - "=d" (edx) : "a" (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 +166,7 @@ void validate_cpuid(void) exit(1); } - asm("cpuid" : "=a" (fms), "=c" (ecx), "=d" (edx) : "a" (1) : "ebx"); + cpuid(1, &fms, NULL, &ecx, &edx); family = (fms >> 8) & 0xf; model = (fms >> 4) & 0xf; stepping = fms & 0xf; @@ -173,7 +188,7 @@ 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, &eax, &ebx, &ecx, &edx); if (verbose) printf("CPUID.06H.ECX: 0x%x\n", ecx); if (!(ecx & (1 << 3))) { -- 1.7.1
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