x86 vdso gettc: Add RDTSCP support
Detect and use RDTSCP if available, instead of fence+RDTSC. For AMD Zens+, use LFENCE+RDTSC instead of RDTSCP (or MFENCE;RDTSC previously). Reviewed by: gallatin, markj Tested by: pho MFC after: 1 week Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D27986
This commit is contained in:
parent
5bf4bafd13
commit
cd240c9cf1
@ -63,6 +63,16 @@ rdtsc_low(const struct vdso_timehands *th)
|
|||||||
return (rv);
|
return (rv);
|
||||||
}
|
}
|
||||||
|
|
||||||
|
static inline u_int
|
||||||
|
rdtscp_low(const struct vdso_timehands *th)
|
||||||
|
{
|
||||||
|
u_int rv;
|
||||||
|
|
||||||
|
__asm __volatile("rdtscp; movl %%edi,%%ecx; shrd %%cl, %%edx, %0"
|
||||||
|
: "=a" (rv) : "D" (th->th_x86_shift) : "ecx", "edx");
|
||||||
|
return (rv);
|
||||||
|
}
|
||||||
|
|
||||||
static u_int
|
static u_int
|
||||||
rdtsc_low_mb_lfence(const struct vdso_timehands *th)
|
rdtsc_low_mb_lfence(const struct vdso_timehands *th)
|
||||||
{
|
{
|
||||||
@ -103,6 +113,12 @@ rdtsc32_mb_none(void)
|
|||||||
return (rdtsc32());
|
return (rdtsc32());
|
||||||
}
|
}
|
||||||
|
|
||||||
|
static u_int
|
||||||
|
rdtscp32_(void)
|
||||||
|
{
|
||||||
|
return (rdtscp32());
|
||||||
|
}
|
||||||
|
|
||||||
struct tsc_selector_tag {
|
struct tsc_selector_tag {
|
||||||
u_int (*ts_rdtsc32)(void);
|
u_int (*ts_rdtsc32)(void);
|
||||||
u_int (*ts_rdtsc_low)(const struct vdso_timehands *);
|
u_int (*ts_rdtsc_low)(const struct vdso_timehands *);
|
||||||
@ -121,6 +137,10 @@ static const struct tsc_selector_tag tsc_selector[] = {
|
|||||||
.ts_rdtsc32 = rdtsc32_mb_none,
|
.ts_rdtsc32 = rdtsc32_mb_none,
|
||||||
.ts_rdtsc_low = rdtsc_low_mb_none,
|
.ts_rdtsc_low = rdtsc_low_mb_none,
|
||||||
},
|
},
|
||||||
|
[3] = { /* RDTSCP */
|
||||||
|
.ts_rdtsc32 = rdtscp32_,
|
||||||
|
.ts_rdtsc_low = rdtscp_low,
|
||||||
|
},
|
||||||
};
|
};
|
||||||
|
|
||||||
static int
|
static int
|
||||||
@ -144,6 +164,9 @@ tsc_selector_idx(u_int cpu_feature)
|
|||||||
do_cpuid(1, p);
|
do_cpuid(1, p);
|
||||||
cpu_id = p[0];
|
cpu_id = p[0];
|
||||||
|
|
||||||
|
if (amd_cpu && CPUID_TO_FAMILY(cpu_id) >= 0x17)
|
||||||
|
return (0);
|
||||||
|
|
||||||
if (cpu_feature != 0) {
|
if (cpu_feature != 0) {
|
||||||
do_cpuid(0x80000000, p);
|
do_cpuid(0x80000000, p);
|
||||||
cpu_exthigh = p[0];
|
cpu_exthigh = p[0];
|
||||||
@ -157,6 +180,8 @@ tsc_selector_idx(u_int cpu_feature)
|
|||||||
amd_feature = 0;
|
amd_feature = 0;
|
||||||
}
|
}
|
||||||
|
|
||||||
|
if ((amd_feature & AMDID_RDTSCP) != 0)
|
||||||
|
return (3);
|
||||||
if ((cpu_feature & CPUID_SSE2) == 0)
|
if ((cpu_feature & CPUID_SSE2) == 0)
|
||||||
return (2);
|
return (2);
|
||||||
return (amd_cpu ? 1 : 0);
|
return (amd_cpu ? 1 : 0);
|
||||||
|
Loading…
Reference in New Issue
Block a user