- 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;