diff options
| author | Ian Moffett <ian@osmora.org> | 2025-08-13 00:06:02 -0400 |
|---|---|---|
| committer | Ian Moffett <ian@osmora.org> | 2025-08-13 03:37:02 -0400 |
| commit | e1b4932b5a133351e9d4aefee9c9f7280f86412f (patch) | |
| tree | 77dd83162ac7e576e9e0a9ee121fe4d73f5975a2 /sys | |
| parent | 83372e621621cd8509adc164599b212406970576 (diff) | |
kernel/amd64: cpu: Add detection of invariant TSC
This commit introduces the 'CPU_FEAT_TSCINV' feature bit to indicate
whether or not the CPU supports an invariant TSC.
Signed-off-by: Ian Moffett <ian@osmora.org>
Diffstat (limited to 'sys')
| -rw-r--r-- | sys/arch/amd64/amd64/machdep.c | 10 | ||||
| -rw-r--r-- | sys/include/arch/amd64/cpu.h | 7 |
2 files changed, 13 insertions, 4 deletions
diff --git a/sys/arch/amd64/amd64/machdep.c b/sys/arch/amd64/amd64/machdep.c index 6408ad3..3338caa 100644 --- a/sys/arch/amd64/amd64/machdep.c +++ b/sys/arch/amd64/amd64/machdep.c @@ -306,7 +306,7 @@ cpu_get_vendor(struct cpu_info *ci) static void cpu_get_info(struct cpu_info *ci) { - uint32_t eax, ebx, ecx, unused; + uint32_t unused, eax, ebx, ecx, edx; uint8_t ext_model, ext_family; /* Get the vendor information */ @@ -322,6 +322,14 @@ cpu_get_info(struct cpu_info *ci) ci->feat |= CPU_FEAT_UMIP; /* + * Processor power management information bits as well + * as bits describing RAS capabilities + */ + CPUID(0x80000007, unused, unused, unused, edx); + if (ISSET(edx, BIT(8))) + ci->feat |= CPU_FEAT_TSCINV; + + /* * Processor info and feature bits */ CPUID(0x01, eax, unused, unused, unused); diff --git a/sys/include/arch/amd64/cpu.h b/sys/include/arch/amd64/cpu.h index 3dadebd..6ed675e 100644 --- a/sys/include/arch/amd64/cpu.h +++ b/sys/include/arch/amd64/cpu.h @@ -42,9 +42,10 @@ #define CPU_IRQ(IRQ_N) (BIT((IRQ_N)) & 0xFF) /* Feature bits */ -#define CPU_FEAT_SMAP BIT(0) -#define CPU_FEAT_SMEP BIT(1) -#define CPU_FEAT_UMIP BIT(2) +#define CPU_FEAT_SMAP BIT(0) +#define CPU_FEAT_SMEP BIT(1) +#define CPU_FEAT_UMIP BIT(2) +#define CPU_FEAT_TSCINV BIT(3) /* TSC invariant */ /* CPU vendors */ #define CPU_VENDOR_OTHER 0x00000000 |