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implement timer for arm >= v6
Signed-off-by: Khem Raj <raj.khem@gmail.com>
--- a/utilities/transactions/lock/range/range_tree/lib/portability/toku_time.h
+++ b/utilities/transactions/lock/range/range_tree/lib/portability/toku_time.h
@@ -161,6 +161,20 @@ static inline tokutime_t toku_time_now(v
struct timeval tv;
gettimeofday(&tv, nullptr);
return (uint64_t)tv.tv_sec * 1000000 + tv.tv_usec;
+#elif (__ARM_ARCH >= 6)
+ uint32_t pmccntr;
+ uint32_t pmuseren;
+ uint32_t pmcntenset;
+ // Read the user mode perf monitor counter access permissions.
+ asm volatile("mrc p15, 0, %0, c9, c14, 0" : "=r"(pmuseren));
+ if (pmuseren & 1) { // Allows reading perfmon counters for user mode code.
+ asm volatile("mrc p15, 0, %0, c9, c12, 1" : "=r"(pmcntenset));
+ if (pmcntenset & 0x80000000ul) { // Is it counting?
+ asm volatile("mrc p15, 0, %0, c9, c13, 0" : "=r"(pmccntr));
+ // The counter is set up to count every 64th cycle
+ return (uint64_t)pmccntr * 64; // Should optimize to << 6
+ }
+ }
#else
#error No timer implementation for this platform
#endif
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