summaryrefslogtreecommitdiff
path: root/arch/x86/include/asm/msr.h
diff options
context:
space:
mode:
authorIngo Molnar <mingo@kernel.org>2015-08-21 08:33:53 +0200
committerIngo Molnar <mingo@kernel.org>2015-08-21 08:35:42 +0200
commit99770737ca7e3ebc14e66460a69b7032de9421e1 (patch)
treeae8eb1bb2d7948fb28d8f10ebd217496ff524215 /arch/x86/include/asm/msr.h
parenta9c909ce8c7853b4fc16055c50eb50d91e20cb93 (diff)
x86/asm/tsc: Add rdtscll() merge helper
Some in-flight code makes use of the old rdtscll() (now removed), provide a wrapper for a kernel cycle to smooth the transition to rdtsc(). ( We use the safest variant, rdtsc_ordered(), which has barriers - this adds another incentive to remove the wrapper in the future. ) Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@suse.de> 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/dddbf98a2af53312e9aa73a5a2b1622fe5d6f52b.1434501121.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/include/asm/msr.h')
-rw-r--r--arch/x86/include/asm/msr.h3
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/x86/include/asm/msr.h b/arch/x86/include/asm/msr.h
index 131eec2ca137..54e9f088919d 100644
--- a/arch/x86/include/asm/msr.h
+++ b/arch/x86/include/asm/msr.h
@@ -152,6 +152,9 @@ static __always_inline unsigned long long rdtsc_ordered(void)
return rdtsc();
}
+/* Deprecated, keep it for a cycle for easier merging: */
+#define rdtscll(now) do { (now) = rdtsc_ordered(); } while (0)
+
static inline unsigned long long native_read_pmc(int counter)
{
DECLARE_ARGS(val, low, high);