Commit 56f335c8 authored by Grant Grundler's avatar Grant Grundler Committed by Matthew Wilcox
Browse files

[PARISC] Add new function to start local Interval Timer, start_cpu_itimer() 



I couldn't find where the itimer was getting started for slave CPUs.
CPU 0 (master) itimer was started in time_init() (arch/parisc/kernel/time.c).
start_cpu_itimer() code was striped from time_init().
Slaves now start their itimer in smp_cpu_init().

This is a first step towards making gettimeoffset() work for SMP.
Next step will be to determine the CR16 (cycle counter)
offsets for each CPU relative to the master (CPU 0).

Signed-off-by: default avatarGrant Grundler <grundler@parisc-linux.org>
Signed-off-by: default avatarKyle McMartin <kyle@parisc-linux.org>
parent 7908a0c7

arch/parisc/kernel/smp.c

+3 −1
Original line number Diff line number Diff line
@@ -430,8 +430,9 @@ smp_do_timer(struct pt_regs *regs) 
static void __init

smp_cpu_init(int cpunum)

{

	extern int init_per_cpu(int);  /* arch/parisc/kernel/setup.c */

	extern int init_per_cpu(int);  /* arch/parisc/kernel/processor.c */

	extern void init_IRQ(void);    /* arch/parisc/kernel/irq.c */

	extern void start_cpu_itimer(void); /* arch/parisc/kernel/time.c */



	/* Set modes and Enable floating point coprocessor */

	(void) init_per_cpu(cpunum);
@@ -457,6 +458,7 @@ smp_cpu_init(int cpunum) 
	enter_lazy_tlb(&init_mm, current);



	init_IRQ();   /* make sure no IRQ's are enabled or pending */

	start_cpu_itimer();

}

arch/parisc/kernel/time.c

+11 −9
Original line number Diff line number Diff line
@@ -223,22 +223,24 @@ unsigned long long sched_clock(void) 
}





void __init start_cpu_itimer(void)

{

	unsigned int cpu = smp_processor_id();

	unsigned long next_tick = mfctl(16) + clocktick;



	mtctl(next_tick, 16);		/* kick off Interval Timer (CR16) */



	cpu_data[cpu].it_value = next_tick;

}



void __init time_init(void)

{

	unsigned long next_tick;

	static struct pdc_tod tod_data;



	clocktick = (100 * PAGE0->mem_10msec) / HZ;

	halftick = clocktick / 2;



	/* Setup clock interrupt timing */



	next_tick = mfctl(16);

	next_tick += clocktick;

	cpu_data[smp_processor_id()].it_value = next_tick;



	/* kick off Itimer (CR16) */

	mtctl(next_tick, 16);

	start_cpu_itimer();	/* get CPU 0 started */



	if(pdc_tod_read(&tod_data) == 0) {

		write_seqlock_irq(&xtime_lock);

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