| Message ID | a7ef693b7a4c88dd2173dc1d4bf6bc27023626eb.1449702533.git.luto@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 10/12/2015 00:12, Andy Lutomirski wrote: > Now that pvclock doesn't require access to the fixmap, all vdso > variants can use it. > > The kernel side isn't wired up for 32-bit kernels yet, but this > covers 32-bit and x32 userspace on 64-bit kernels. > > Signed-off-by: Andy Lutomirski <luto@kernel.org> > --- > arch/x86/entry/vdso/vclock_gettime.c | 91 ++++++++++++++++-------------------- > 1 file changed, 40 insertions(+), 51 deletions(-) > > diff --git a/arch/x86/entry/vdso/vclock_gettime.c b/arch/x86/entry/vdso/vclock_gettime.c > index 59a98c25bde7..8602f06c759f 100644 > --- a/arch/x86/entry/vdso/vclock_gettime.c > +++ b/arch/x86/entry/vdso/vclock_gettime.c > @@ -17,8 +17,10 @@ > #include <asm/vvar.h> > #include <asm/unistd.h> > #include <asm/msr.h> > +#include <asm/pvclock.h> > #include <linux/math64.h> > #include <linux/time.h> > +#include <linux/kernel.h> > > #define gtod (&VVAR(vsyscall_gtod_data)) > > @@ -43,10 +45,6 @@ extern u8 pvclock_page > > #ifndef BUILD_VDSO32 > > -#include <linux/kernel.h> > -#include <asm/vsyscall.h> > -#include <asm/pvclock.h> > - > notrace static long vdso_fallback_gettime(long clock, struct timespec *ts) > { > long ret; > @@ -64,8 +62,42 @@ notrace static long vdso_fallback_gtod(struct timeval *tv, struct timezone *tz) > return ret; > } > > -#ifdef CONFIG_PARAVIRT_CLOCK > > +#else > + > +notrace static long vdso_fallback_gettime(long clock, struct timespec *ts) > +{ > + long ret; > + > + asm( > + "mov %%ebx, %%edx \n" > + "mov %2, %%ebx \n" > + "call __kernel_vsyscall \n" > + "mov %%edx, %%ebx \n" > + : "=a" (ret) > + : "0" (__NR_clock_gettime), "g" (clock), "c" (ts) > + : "memory", "edx"); > + return ret; > +} > + > +notrace static long vdso_fallback_gtod(struct timeval *tv, struct timezone *tz) > +{ > + long ret; > + > + asm( > + "mov %%ebx, %%edx \n" > + "mov %2, %%ebx \n" > + "call __kernel_vsyscall \n" > + "mov %%edx, %%ebx \n" > + : "=a" (ret) > + : "0" (__NR_gettimeofday), "g" (tv), "c" (tz) > + : "memory", "edx"); > + return ret; > +} > + > +#endif > + > +#ifdef CONFIG_PARAVIRT_CLOCK > static notrace const struct pvclock_vsyscall_time_info *get_pvti0(void) > { > return (const struct pvclock_vsyscall_time_info *)&pvclock_page; > @@ -109,9 +141,9 @@ static notrace cycle_t vread_pvclock(int *mode) > do { > version = pvti->version; > > - /* This is also a read barrier, so we'll read version first. */ > - tsc = rdtsc_ordered(); > + smp_rmb(); > > + tsc = rdtsc_ordered(); > pvti_tsc_to_system_mul = pvti->tsc_to_system_mul; > pvti_tsc_shift = pvti->tsc_shift; > pvti_system_time = pvti->system_time; > @@ -126,7 +158,7 @@ static notrace cycle_t vread_pvclock(int *mode) > pvclock_scale_delta(delta, pvti_tsc_to_system_mul, > pvti_tsc_shift); > > - /* refer to tsc.c read_tsc() comment for rationale */ > + /* refer to vread_tsc() comment for rationale */ > last = gtod->cycle_last; > > if (likely(ret >= last)) > @@ -136,49 +168,6 @@ static notrace cycle_t vread_pvclock(int *mode) > } > #endif > > -#else > - > -notrace static long vdso_fallback_gettime(long clock, struct timespec *ts) > -{ > - long ret; > - > - asm( > - "mov %%ebx, %%edx \n" > - "mov %2, %%ebx \n" > - "call __kernel_vsyscall \n" > - "mov %%edx, %%ebx \n" > - : "=a" (ret) > - : "0" (__NR_clock_gettime), "g" (clock), "c" (ts) > - : "memory", "edx"); > - return ret; > -} > - > -notrace static long vdso_fallback_gtod(struct timeval *tv, struct timezone *tz) > -{ > - long ret; > - > - asm( > - "mov %%ebx, %%edx \n" > - "mov %2, %%ebx \n" > - "call __kernel_vsyscall \n" > - "mov %%edx, %%ebx \n" > - : "=a" (ret) > - : "0" (__NR_gettimeofday), "g" (tv), "c" (tz) > - : "memory", "edx"); > - return ret; > -} > - > -#ifdef CONFIG_PARAVIRT_CLOCK > - > -static notrace cycle_t vread_pvclock(int *mode) > -{ > - *mode = VCLOCK_NONE; > - return 0; > -} > -#endif > - > -#endif > - > notrace static cycle_t vread_tsc(void) > { > cycle_t ret = (cycle_t)rdtsc_ordered(); > Acked-by: Paolo Bonzini <pbonzini@redhat.com> -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/arch/x86/entry/vdso/vclock_gettime.c b/arch/x86/entry/vdso/vclock_gettime.c index 59a98c25bde7..8602f06c759f 100644 --- a/arch/x86/entry/vdso/vclock_gettime.c +++ b/arch/x86/entry/vdso/vclock_gettime.c @@ -17,8 +17,10 @@ #include <asm/vvar.h> #include <asm/unistd.h> #include <asm/msr.h> +#include <asm/pvclock.h> #include <linux/math64.h> #include <linux/time.h> +#include <linux/kernel.h> #define gtod (&VVAR(vsyscall_gtod_data)) @@ -43,10 +45,6 @@ extern u8 pvclock_page #ifndef BUILD_VDSO32 -#include <linux/kernel.h> -#include <asm/vsyscall.h> -#include <asm/pvclock.h> - notrace static long vdso_fallback_gettime(long clock, struct timespec *ts) { long ret; @@ -64,8 +62,42 @@ notrace static long vdso_fallback_gtod(struct timeval *tv, struct timezone *tz) return ret; } -#ifdef CONFIG_PARAVIRT_CLOCK +#else + +notrace static long vdso_fallback_gettime(long clock, struct timespec *ts) +{ + long ret; + + asm( + "mov %%ebx, %%edx \n" + "mov %2, %%ebx \n" + "call __kernel_vsyscall \n" + "mov %%edx, %%ebx \n" + : "=a" (ret) + : "0" (__NR_clock_gettime), "g" (clock), "c" (ts) + : "memory", "edx"); + return ret; +} + +notrace static long vdso_fallback_gtod(struct timeval *tv, struct timezone *tz) +{ + long ret; + + asm( + "mov %%ebx, %%edx \n" + "mov %2, %%ebx \n" + "call __kernel_vsyscall \n" + "mov %%edx, %%ebx \n" + : "=a" (ret) + : "0" (__NR_gettimeofday), "g" (tv), "c" (tz) + : "memory", "edx"); + return ret; +} + +#endif + +#ifdef CONFIG_PARAVIRT_CLOCK static notrace const struct pvclock_vsyscall_time_info *get_pvti0(void) { return (const struct pvclock_vsyscall_time_info *)&pvclock_page; @@ -109,9 +141,9 @@ static notrace cycle_t vread_pvclock(int *mode) do { version = pvti->version; - /* This is also a read barrier, so we'll read version first. */ - tsc = rdtsc_ordered(); + smp_rmb(); + tsc = rdtsc_ordered(); pvti_tsc_to_system_mul = pvti->tsc_to_system_mul; pvti_tsc_shift = pvti->tsc_shift; pvti_system_time = pvti->system_time; @@ -126,7 +158,7 @@ static notrace cycle_t vread_pvclock(int *mode) pvclock_scale_delta(delta, pvti_tsc_to_system_mul, pvti_tsc_shift); - /* refer to tsc.c read_tsc() comment for rationale */ + /* refer to vread_tsc() comment for rationale */ last = gtod->cycle_last; if (likely(ret >= last)) @@ -136,49 +168,6 @@ static notrace cycle_t vread_pvclock(int *mode) } #endif -#else - -notrace static long vdso_fallback_gettime(long clock, struct timespec *ts) -{ - long ret; - - asm( - "mov %%ebx, %%edx \n" - "mov %2, %%ebx \n" - "call __kernel_vsyscall \n" - "mov %%edx, %%ebx \n" - : "=a" (ret) - : "0" (__NR_clock_gettime), "g" (clock), "c" (ts) - : "memory", "edx"); - return ret; -} - -notrace static long vdso_fallback_gtod(struct timeval *tv, struct timezone *tz) -{ - long ret; - - asm( - "mov %%ebx, %%edx \n" - "mov %2, %%ebx \n" - "call __kernel_vsyscall \n" - "mov %%edx, %%ebx \n" - : "=a" (ret) - : "0" (__NR_gettimeofday), "g" (tv), "c" (tz) - : "memory", "edx"); - return ret; -} - -#ifdef CONFIG_PARAVIRT_CLOCK - -static notrace cycle_t vread_pvclock(int *mode) -{ - *mode = VCLOCK_NONE; - return 0; -} -#endif - -#endif - notrace static cycle_t vread_tsc(void) { cycle_t ret = (cycle_t)rdtsc_ordered();
Now that pvclock doesn't require access to the fixmap, all vdso variants can use it. The kernel side isn't wired up for 32-bit kernels yet, but this covers 32-bit and x32 userspace on 64-bit kernels. Signed-off-by: Andy Lutomirski <luto@kernel.org> --- arch/x86/entry/vdso/vclock_gettime.c | 91 ++++++++++++++++-------------------- 1 file changed, 40 insertions(+), 51 deletions(-)