ia64: convert to legacy_timer_tick

ia64 is the only architecture that calls xtime_update() in a loop,
once for each jiffie that has passed since the last event.

Before commit 3171a0305d62 ("[PATCH] simplify update_times (avoid
jiffies/jiffies_64 aliasing problem)") in 2006, it could not actually do
this any differently, but now it seems simpler to just pass the number
of jiffies that passed in the meantime.

While this loses the ability process interrupts in the middle of
the timer tick by calling local_irq_enable(), doing so is fairly
peculiar anyway and it seems better to just do what everyone
else does here.

Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig
index 39b25a5a591b309bc213ba04e7a2f54145f03d27..db8c2a365b70c0d03fe8573836f7069b23294a92 100644 (file)
--- a/arch/ia64/Kconfig
+++ b/arch/ia64/Kconfig
@@ -46,6 +46,7 @@ config IA64
        select ARCH_THREAD_STACK_ALLOCATOR
        select ARCH_CLOCKSOURCE_DATA
        select GENERIC_TIME_VSYSCALL
+       select LEGACY_TIMER_TICK
        select SWIOTLB
        select SYSCTL_ARCH_UNALIGN_NO_WARN
        select HAVE_MOD_ARCH_SPECIFIC

diff --git a/arch/ia64/kernel/time.c b/arch/ia64/kernel/time.c
index 7abc5f37bfaf94cf383364df3dd042da405243a5..9431edb08508e3f3a66231d34a3bc81e3fab60ef 100644 (file)
--- a/arch/ia64/kernel/time.c
+++ b/arch/ia64/kernel/time.c
@@ -161,39 +161,29 @@ void vtime_account_idle(struct task_struct *tsk)
 static irqreturn_t
 timer_interrupt (int irq, void *dev_id)
 {
-       unsigned long new_itm;
+       unsigned long cur_itm, new_itm, ticks;
 
        if (cpu_is_offline(smp_processor_id())) {
                return IRQ_HANDLED;
        }
 
        new_itm = local_cpu_data->itm_next;
+       cur_itm = ia64_get_itc();
 
-       if (!time_after(ia64_get_itc(), new_itm))
+       if (!time_after(cur_itm, new_itm)) {
                printk(KERN_ERR "Oops: timer tick before it's due (itc=%lx,itm=%lx)\n",
-                      ia64_get_itc(), new_itm);
-
-       profile_tick(CPU_PROFILING);
-
-       while (1) {
-               update_process_times(user_mode(get_irq_regs()));
-
-               new_itm += local_cpu_data->itm_delta;
-
-               if (smp_processor_id() == time_keeper_id)
-                       xtime_update(1);
-
-               local_cpu_data->itm_next = new_itm;
+                      cur_itm, new_itm);
+               ticks = 1;
+       } else {
+               ticks = DIV_ROUND_UP(cur_itm - new_itm,
+                                    local_cpu_data->itm_delta);
+               new_itm += ticks * local_cpu_data->itm_delta;
+       }
 
-               if (time_after(new_itm, ia64_get_itc()))
-                       break;
+       if (smp_processor_id() != time_keeper_id)
+               ticks = 0;
 
-               /*
-                * Allow IPIs to interrupt the timer loop.
-                */
-               local_irq_enable();
-               local_irq_disable();
-       }
+       legacy_timer_tick(ticks);
 
        do {
                /*