Merge tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi

[linux-2.6-microblaze.git] / arch / s390 / lib / delay.c

diff --git a/arch/s390/lib/delay.c b/arch/s390/lib/delay.c
index 68d61f2..f289afe 100644 (file)
--- a/arch/s390/lib/delay.c
+++ b/arch/s390/lib/delay.c
@@ -19,13 +19,6 @@
 #include <asm/div64.h>
 #include <asm/idle.h>
 
-static DEFINE_STATIC_KEY_FALSE(udelay_ready);
-
-void __init udelay_enable(void)
-{
-       static_branch_enable(&udelay_ready);
-}
-
 void __delay(unsigned long loops)
 {
         /*
@@ -39,105 +32,25 @@ void __delay(unsigned long loops)
 }
 EXPORT_SYMBOL(__delay);
 
-static void __udelay_disabled(unsigned long long usecs)
+static void delay_loop(unsigned long delta)
 {
-       unsigned long cr0, cr0_new, psw_mask;
-       struct s390_idle_data idle;
-       u64 end;
+       unsigned long end;
 
-       end = get_tod_clock() + (usecs << 12);
-       __ctl_store(cr0, 0, 0);
-       cr0_new = cr0 & ~CR0_IRQ_SUBCLASS_MASK;
-       cr0_new |= (1UL << (63 - 52)); /* enable clock comparator irq */
-       __ctl_load(cr0_new, 0, 0);
-       psw_mask = __extract_psw() | PSW_MASK_EXT | PSW_MASK_WAIT;
-       set_clock_comparator(end);
-       set_cpu_flag(CIF_IGNORE_IRQ);
-       psw_idle(&idle, psw_mask);
-       trace_hardirqs_off();
-       clear_cpu_flag(CIF_IGNORE_IRQ);
-       set_clock_comparator(S390_lowcore.clock_comparator);
-       __ctl_load(cr0, 0, 0);
+       end = get_tod_clock_monotonic() + delta;
+       while (!tod_after(get_tod_clock_monotonic(), end))
+               cpu_relax();
 }
 
-static void __udelay_enabled(unsigned long long usecs)
+void __udelay(unsigned long usecs)
 {
-       u64 clock_saved, end;
-
-       end = get_tod_clock_fast() + (usecs << 12);
-       do {
-               clock_saved = 0;
-               if (tod_after(S390_lowcore.clock_comparator, end)) {
-                       clock_saved = local_tick_disable();
-                       set_clock_comparator(end);
-               }
-               enabled_wait();
-               if (clock_saved)
-                       local_tick_enable(clock_saved);
-       } while (get_tod_clock_fast() < end);
-}
-
-/*
- * Waits for 'usecs' microseconds using the TOD clock comparator.
- */
-void __udelay(unsigned long long usecs)
-{
-       unsigned long flags;
-
-       if (!static_branch_likely(&udelay_ready)) {
-               udelay_simple(usecs);
-               return;
-       }
-
-       preempt_disable();
-       local_irq_save(flags);
-       if (in_irq()) {
-               __udelay_disabled(usecs);
-               goto out;
-       }
-       if (in_softirq()) {
-               if (raw_irqs_disabled_flags(flags))
-                       __udelay_disabled(usecs);
-               else
-                       __udelay_enabled(usecs);
-               goto out;
-       }
-       if (raw_irqs_disabled_flags(flags)) {
-               local_bh_disable();
-               __udelay_disabled(usecs);
-               _local_bh_enable();
-               goto out;
-       }
-       __udelay_enabled(usecs);
-out:
-       local_irq_restore(flags);
-       preempt_enable();
+       delay_loop(usecs << 12);
 }
 EXPORT_SYMBOL(__udelay);
 
-/*
- * Simple udelay variant. To be used on startup and reboot
- * when the interrupt handler isn't working.
- */
-void udelay_simple(unsigned long long usecs)
-{
-       u64 end;
-
-       end = get_tod_clock_fast() + (usecs << 12);
-       while (get_tod_clock_fast() < end)
-               cpu_relax();
-}
-
-void __ndelay(unsigned long long nsecs)
+void __ndelay(unsigned long nsecs)
 {
-       u64 end;
-
        nsecs <<= 9;
        do_div(nsecs, 125);
-       end = get_tod_clock_fast() + nsecs;
-       if (nsecs & ~0xfffUL)
-               __udelay(nsecs >> 12);
-       while (get_tod_clock_fast() < end)
-               barrier();
+       delay_loop(nsecs);
 }
 EXPORT_SYMBOL(__ndelay);