irqreturn_t smtc_timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
{
int cpu = smp_processor_id();
int vpflags;
if (read_c0_cause() & (1 << 30)) {
/* If timer interrupt, make it de-assert */
write_c0_compare (read_c0_count() - 1);
vpflags = dvpe();
clear_c0_cause(0x100<<7);
evpe(vpflags);
/*
* There are things we only want to do once per tick
* in an "MP" system. One TC of each VPE will take
* the actual timer interrupt. The others will get
* timer broadcast IPIs. We use whoever it is that takes
* the tick on VPE 0 to run the full timer_interrupt().
*/
if (cpu_data[cpu].vpe_id == 0) {
timer_interrupt(irq, NULL, regs);
smtc_timer_broadcast(cpu_data[cpu].vpe_id);
} else {
write_c0_compare(read_c0_count() + (mips_hpt_frequency/HZ));
local_timer_interrupt(irq, dev_id, regs);
smtc_timer_broadcast(cpu_data[cpu].vpe_id);
}
}
return IRQ_HANDLED;
}
irqreturn_t sim_timer_interrupt(int irq, void *dev_id)
{
#ifdef CONFIG_SMP
int cpu = smp_processor_id();
/*
* CPU 0 handles the global timer interrupt job
* resets count/compare registers to trigger next timer int.
*/
#ifndef CONFIG_MIPS_MT_SMTC
if (cpu == 0) {
timer_interrupt(irq, dev_id);
} else {
/* Everyone else needs to reset the timer int here as
ll_local_timer_interrupt doesn't */
/*
* FIXME: need to cope with counter underflow.
* More support needs to be added to kernel/time for
* counter/timer interrupts on multiple CPU's
*/
write_c0_compare (read_c0_count() + ( mips_hpt_frequency/HZ));
}
#else /* SMTC */
/*
* In SMTC system, one Count/Compare set exists per VPE.
* Which TC within a VPE gets the interrupt is essentially
* random - we only know that it shouldn't be one with
* IXMT set. Whichever TC gets the interrupt needs to
* send special interprocessor interrupts to the other
* TCs to make sure that they schedule, etc.
*
* That code is specific to the SMTC kernel, not to
* the simulation platform, so it's invoked from
* the general MIPS timer_interrupt routine.
*
* We have a problem in that the interrupt vector code
* had to turn off the timer IM bit to avoid redundant
* entries, but we may never get to mips_cpu_irq_end
* to turn it back on again if the scheduler gets
* involved. So we clear the pending timer here,
* and re-enable the mask...
*/
int vpflags = dvpe();
write_c0_compare (read_c0_count() - 1);
clear_c0_cause(0x100 << cp0_compare_irq);
set_c0_status(0x100 << cp0_compare_irq);
irq_enable_hazard();
evpe(vpflags);
if (cpu_data[cpu].vpe_id == 0)
timer_interrupt(irq, dev_id);
else
write_c0_compare (read_c0_count() + ( mips_hpt_frequency/HZ));
smtc_timer_broadcast(cpu_data[cpu].vpe_id);
#endif /* CONFIG_MIPS_MT_SMTC */
/*
* every CPU should do profiling and process accounting
*/
local_timer_interrupt (irq, dev_id);
return IRQ_HANDLED;
#else
return timer_interrupt (irq, dev_id);
#endif
}
irqreturn_t mips_timer_interrupt(int irq, void *dev_id)
{
int cpu = smp_processor_id();
#ifdef CONFIG_MIPS_MT_SMTC
/*
* In an SMTC system, one Count/Compare set exists per VPE.
* Which TC within a VPE gets the interrupt is essentially
* random - we only know that it shouldn't be one with
* IXMT set. Whichever TC gets the interrupt needs to
* send special interprocessor interrupts to the other
* TCs to make sure that they schedule, etc.
*
* That code is specific to the SMTC kernel, not to
* the a particular platform, so it's invoked from
* the general MIPS timer_interrupt routine.
*/
int vpflags;
/*
* We could be here due to timer interrupt,
* perf counter overflow, or both.
*/
if (read_c0_cause() & (1 << 26))
perf_irq();
if (read_c0_cause() & (1 << 30)) {
/* If timer interrupt, make it de-assert */
write_c0_compare (read_c0_count() - 1);
/*
* DVPE is necessary so long as cross-VPE interrupts
* are done via read-modify-write of Cause register.
*/
vpflags = dvpe();
clear_c0_cause(CPUCTR_IMASKBIT);
evpe(vpflags);
/*
* There are things we only want to do once per tick
* in an "MP" system. One TC of each VPE will take
* the actual timer interrupt. The others will get
* timer broadcast IPIs. We use whoever it is that takes
* the tick on VPE 0 to run the full timer_interrupt().
*/
if (cpu_data[cpu].vpe_id == 0) {
timer_interrupt(irq, NULL);
smtc_timer_broadcast(cpu_data[cpu].vpe_id);
scroll_display_message();
} else {
write_c0_compare(read_c0_count() +
(mips_hpt_frequency/HZ));
local_timer_interrupt(irq, dev_id);
smtc_timer_broadcast(cpu_data[cpu].vpe_id);
}
}
#else /* CONFIG_MIPS_MT_SMTC */
int r2 = cpu_has_mips_r2;
if (cpu == 0) {
/*
* CPU 0 handles the global timer interrupt job and process
* accounting resets count/compare registers to trigger next
* timer int.
*/
if (!r2 || (read_c0_cause() & (1 << 26)))
if (perf_irq())
goto out;
/* we keep interrupt disabled all the time */
if (!r2 || (read_c0_cause() & (1 << 30)))
timer_interrupt(irq, NULL);
scroll_display_message();
} else {
/* Everyone else needs to reset the timer int here as
ll_local_timer_interrupt doesn't */
/*
* FIXME: need to cope with counter underflow.
* More support needs to be added to kernel/time for
* counter/timer interrupts on multiple CPU's
*/
write_c0_compare(read_c0_count() + (mips_hpt_frequency/HZ));
/*
* Other CPUs should do profiling and process accounting
*/
local_timer_interrupt(irq, dev_id);
}
out:
#endif /* CONFIG_MIPS_MT_SMTC */
return IRQ_HANDLED;
}
