Messages in this thread Patch in this message | | | Date | Mon, 6 Jul 2015 08:40:06 -0700 | From | tip-bot for Andy Lutomirski <> | Subject | [tip:x86/asm] x86/asm/tsc, kvm: Remove vget_cycles() |
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Commit-ID: 881d7bf843d7139c6dfbffdec4903b3354423c49 Gitweb: http://git.kernel.org/tip/881d7bf843d7139c6dfbffdec4903b3354423c49 Author: Andy Lutomirski <luto@kernel.org> AuthorDate: Thu, 25 Jun 2015 18:43:56 +0200 Committer: Ingo Molnar <mingo@kernel.org> CommitDate: Mon, 6 Jul 2015 15:23:25 +0200
x86/asm/tsc, kvm: Remove vget_cycles()
The only caller was KVM's read_tsc(). The only difference between vget_cycles() and native_read_tsc() was that vget_cycles() returned zero instead of crashing on TSC-less systems. KVM already checks vclock_mode() before calling that function, so the extra check is unnecessary. Also, KVM (host-side) requires the TSC to exist.
Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Huang Rui <ray.huang@amd.com> Cc: John Stultz <john.stultz@linaro.org> Cc: Len Brown <lenb@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: kvm ML <kvm@vger.kernel.org> Link: http://lkml.kernel.org/r/20615df14ae2eb713ea7a5f5123c1dc4c7ca993d.1434501121.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org> --- arch/x86/include/asm/tsc.h | 13 ------------- arch/x86/kvm/x86.c | 2 +- 2 files changed, 1 insertion(+), 14 deletions(-)
diff --git a/arch/x86/include/asm/tsc.h b/arch/x86/include/asm/tsc.h index fd11128..3da1cc1 100644 --- a/arch/x86/include/asm/tsc.h +++ b/arch/x86/include/asm/tsc.h @@ -32,19 +32,6 @@ static inline cycles_t get_cycles(void) return ret; } -static __always_inline cycles_t vget_cycles(void) -{ - /* - * We only do VDSOs on TSC capable CPUs, so this shouldn't - * access boot_cpu_data (which is not VDSO-safe): - */ -#ifndef CONFIG_X86_TSC - if (!cpu_has_tsc) - return 0; -#endif - return (cycles_t)native_read_tsc(); -} - extern void tsc_init(void); extern void mark_tsc_unstable(char *reason); extern int unsynchronized_tsc(void); diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index bbaf44e..f771058 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -1455,7 +1455,7 @@ static cycle_t read_tsc(void) * but no one has ever seen it happen. */ rdtsc_barrier(); - ret = (cycle_t)vget_cycles(); + ret = (cycle_t)native_read_tsc(); last = pvclock_gtod_data.clock.cycle_last;
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