Linux 3.10.55

[GitHub/mt8127/android_kernel_alcatel_ttab.git] / arch / arm / kernel / sched_clock.c

diff --git a/arch/arm/kernel/sched_clock.c b/arch/arm/kernel/sched_clock.c
index 59d2adb764a995f9174a6494bd2bcc1974c10e73..e8edcaa0e4323c304d2b7a0cda4105eb3a1088f8 100644 (file)
--- a/arch/arm/kernel/sched_clock.c
+++ b/arch/arm/kernel/sched_clock.c
@@ -20,6 +20,7 @@ struct clock_data {
        u64 epoch_ns;
        u32 epoch_cyc;
        u32 epoch_cyc_copy;
+       unsigned long rate;
        u32 mult;
        u32 shift;
        bool suspended;
@@ -113,11 +114,14 @@ void __init setup_sched_clock(u32 (*read)(void), int bits, unsigned long rate)
        u64 res, wrap;
        char r_unit;
 
+       if (cd.rate > rate)
+               return;
+
        BUG_ON(bits > 32);
        WARN_ON(!irqs_disabled());
-       WARN_ON(read_sched_clock != jiffy_sched_clock_read);
        read_sched_clock = read;
        sched_clock_mask = (1 << bits) - 1;
+       cd.rate = rate;
 
        /* calculate the mult/shift to convert counter ticks to ns. */
        clocks_calc_mult_shift(&cd.mult, &cd.shift, rate, NSEC_PER_SEC, 0);
@@ -161,12 +165,19 @@ void __init setup_sched_clock(u32 (*read)(void), int bits, unsigned long rate)
        pr_debug("Registered %pF as sched_clock source\n", read);
 }
 
-unsigned long long notrace sched_clock(void)
+static unsigned long long notrace sched_clock_32(void)
 {
        u32 cyc = read_sched_clock();
        return cyc_to_sched_clock(cyc, sched_clock_mask);
 }
 
+unsigned long long __read_mostly (*sched_clock_func)(void) = sched_clock_32;
+
+unsigned long long notrace sched_clock(void)
+{
+       return sched_clock_func();
+}
+
 void __init sched_clock_postinit(void)
 {
        /*