projects / people / pmueller / ipfire-2.x.git / blame
| Commit | Line | Data |
|---|---|---|
| 00e5a55c BS |
1 | From: Alok Kataria <akataria@vmware.com> |
| 2 | Subject: x86: VMware: Fix vmware_get_tsc code | |
| 3 | Patch-mainline: | |
| 4 | References: bnc#441338 | |
| 5 | ||
| 6 | Impact: Fix possible failure to calibrate the TSC on Vmware near 4 GHz | |
| 7 | ||
| 8 | The current version of the code to get the tsc frequency from | |
| 9 | the VMware hypervisor, will be broken on processor with frequency | |
| 10 | (4G-1) HZ, because on such processors eax will have UINT_MAX | |
| 11 | and that would be legitimate. | |
| 12 | We instead check that EBX did change to decide if we were able to | |
| 13 | read the frequency from the hypervisor. | |
| 14 | ||
| 15 | Signed-off-by: Alok N Kataria <akataria@vmware.com> | |
| 16 | Signed-off-by: H. Peter Anvin <hpa@zytor.com> | |
| 17 | Signed-off-by: Takashi Iwai <tiwai@suse.de> | |
| 18 | ||
| 19 | --- | |
| 20 | ||
| 21 | arch/x86/kernel/cpu/vmware.c | 4 ++-- | |
| 22 | 1 files changed, 2 insertions(+), 2 deletions(-) | |
| 23 | ||
| 24 | ||
| 25 | diff --git a/arch/x86/kernel/cpu/vmware.c b/arch/x86/kernel/cpu/vmware.c | |
| 26 | index 2ac4394..a0905ec 100644 | |
| 27 | --- a/arch/x86/kernel/cpu/vmware.c | |
| 28 | +++ b/arch/x86/kernel/cpu/vmware.c | |
| 29 | @@ -36,7 +36,7 @@ | |
| 30 | "=a"(eax), "=c"(ecx), "=d"(edx), "=b"(ebx) : \ | |
| 31 | "0"(VMWARE_HYPERVISOR_MAGIC), \ | |
| 32 | "1"(VMWARE_PORT_CMD_##cmd), \ | |
| 33 | - "2"(VMWARE_HYPERVISOR_PORT), "3"(0) : \ | |
| 34 | + "2"(VMWARE_HYPERVISOR_PORT), "3"(UINT_MAX) : \ | |
| 35 | "memory"); | |
| 36 | ||
| 37 | static inline int __vmware_platform(void) | |
| 38 | @@ -53,7 +53,7 @@ static unsigned long __vmware_get_tsc_khz(void) | |
| 39 | ||
| 40 | VMWARE_PORT(GETHZ, eax, ebx, ecx, edx); | |
| 41 | ||
| 42 | - if (eax == (uint32_t)-1) | |
| 43 | + if (ebx == UINT_MAX) | |
| 44 | return 0; | |
| 45 | tsc_hz = eax | (((uint64_t)ebx) << 32); | |
| 46 | do_div(tsc_hz, 1000); |