[MIPS] time: Move R4000 clockevent device code to separate configurable file
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/kernel/cevt-r4k.c b/arch/mips/kernel/cevt-r4k.c
new file mode 100644
index 0000000..08b84d4
--- /dev/null
+++ b/arch/mips/kernel/cevt-r4k.c
@@ -0,0 +1,272 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2007 MIPS Technologies, Inc.
+ * Copyright (C) 2007 Ralf Baechle <ralf@linux-mips.org>
+ */
+#include <linux/clockchips.h>
+#include <linux/interrupt.h>
+#include <linux/percpu.h>
+
+#include <asm/time.h>
+
+static int mips_next_event(unsigned long delta,
+ struct clock_event_device *evt)
+{
+ unsigned int cnt;
+ int res;
+
+#ifdef CONFIG_MIPS_MT_SMTC
+ {
+ unsigned long flags, vpflags;
+ local_irq_save(flags);
+ vpflags = dvpe();
+#endif
+ cnt = read_c0_count();
+ cnt += delta;
+ write_c0_compare(cnt);
+ res = ((long)(read_c0_count() - cnt ) > 0) ? -ETIME : 0;
+#ifdef CONFIG_MIPS_MT_SMTC
+ evpe(vpflags);
+ local_irq_restore(flags);
+ }
+#endif
+ return res;
+}
+
+static void mips_set_mode(enum clock_event_mode mode,
+ struct clock_event_device *evt)
+{
+ /* Nothing to do ... */
+}
+
+static DEFINE_PER_CPU(struct clock_event_device, mips_clockevent_device);
+static int cp0_timer_irq_installed;
+
+/*
+ * Timer ack for an R4k-compatible timer of a known frequency.
+ */
+static void c0_timer_ack(void)
+{
+ write_c0_compare(read_c0_compare());
+}
+
+/*
+ * Possibly handle a performance counter interrupt.
+ * Return true if the timer interrupt should not be checked
+ */
+static inline int handle_perf_irq(int r2)
+{
+ /*
+ * The performance counter overflow interrupt may be shared with the
+ * timer interrupt (cp0_perfcount_irq < 0). If it is and a
+ * performance counter has overflowed (perf_irq() == IRQ_HANDLED)
+ * and we can't reliably determine if a counter interrupt has also
+ * happened (!r2) then don't check for a timer interrupt.
+ */
+ return (cp0_perfcount_irq < 0) &&
+ perf_irq() == IRQ_HANDLED &&
+ !r2;
+}
+
+static irqreturn_t c0_compare_interrupt(int irq, void *dev_id)
+{
+ const int r2 = cpu_has_mips_r2;
+ struct clock_event_device *cd;
+ int cpu = smp_processor_id();
+
+ /*
+ * Suckage alert:
+ * Before R2 of the architecture there was no way to see if a
+ * performance counter interrupt was pending, so we have to run
+ * the performance counter interrupt handler anyway.
+ */
+ if (handle_perf_irq(r2))
+ goto out;
+
+ /*
+ * The same applies to performance counter interrupts. But with the
+ * above we now know that the reason we got here must be a timer
+ * interrupt. Being the paranoiacs we are we check anyway.
+ */
+ if (!r2 || (read_c0_cause() & (1 << 30))) {
+ c0_timer_ack();
+#ifdef CONFIG_MIPS_MT_SMTC
+ if (cpu_data[cpu].vpe_id)
+ goto out;
+ cpu = 0;
+#endif
+ cd = &per_cpu(mips_clockevent_device, cpu);
+ cd->event_handler(cd);
+ }
+
+out:
+ return IRQ_HANDLED;
+}
+
+static struct irqaction c0_compare_irqaction = {
+ .handler = c0_compare_interrupt,
+#ifdef CONFIG_MIPS_MT_SMTC
+ .flags = IRQF_DISABLED,
+#else
+ .flags = IRQF_DISABLED | IRQF_PERCPU,
+#endif
+ .name = "timer",
+};
+
+#ifdef CONFIG_MIPS_MT_SMTC
+DEFINE_PER_CPU(struct clock_event_device, smtc_dummy_clockevent_device);
+
+static void smtc_set_mode(enum clock_event_mode mode,
+ struct clock_event_device *evt)
+{
+}
+
+static void mips_broadcast(cpumask_t mask)
+{
+ unsigned int cpu;
+
+ for_each_cpu_mask(cpu, mask)
+ smtc_send_ipi(cpu, SMTC_CLOCK_TICK, 0);
+}
+
+static void setup_smtc_dummy_clockevent_device(void)
+{
+ //uint64_t mips_freq = mips_hpt_^frequency;
+ unsigned int cpu = smp_processor_id();
+ struct clock_event_device *cd;
+
+ cd = &per_cpu(smtc_dummy_clockevent_device, cpu);
+
+ cd->name = "SMTC";
+ cd->features = CLOCK_EVT_FEAT_DUMMY;
+
+ /* Calculate the min / max delta */
+ cd->mult = 0; //div_sc((unsigned long) mips_freq, NSEC_PER_SEC, 32);
+ cd->shift = 0; //32;
+ cd->max_delta_ns = 0; //clockevent_delta2ns(0x7fffffff, cd);
+ cd->min_delta_ns = 0; //clockevent_delta2ns(0x30, cd);
+
+ cd->rating = 200;
+ cd->irq = 17; //-1;
+// if (cpu)
+// cd->cpumask = CPU_MASK_ALL; // cpumask_of_cpu(cpu);
+// else
+ cd->cpumask = cpumask_of_cpu(cpu);
+
+ cd->set_mode = smtc_set_mode;
+
+ cd->broadcast = mips_broadcast;
+
+ clockevents_register_device(cd);
+}
+#endif
+
+static void mips_event_handler(struct clock_event_device *dev)
+{
+}
+
+/*
+ * FIXME: This doesn't hold for the relocated E9000 compare interrupt.
+ */
+static int c0_compare_int_pending(void)
+{
+ return (read_c0_cause() >> cp0_compare_irq) & 0x100;
+}
+
+static int c0_compare_int_usable(void)
+{
+ const unsigned int delta = 0x300000;
+ unsigned int cnt;
+
+ /*
+ * IP7 already pending? Try to clear it by acking the timer.
+ */
+ if (c0_compare_int_pending()) {
+ write_c0_compare(read_c0_compare());
+ irq_disable_hazard();
+ if (c0_compare_int_pending())
+ return 0;
+ }
+
+ cnt = read_c0_count();
+ cnt += delta;
+ write_c0_compare(cnt);
+
+ while ((long)(read_c0_count() - cnt) <= 0)
+ ; /* Wait for expiry */
+
+ if (!c0_compare_int_pending())
+ return 0;
+
+ write_c0_compare(read_c0_compare());
+ irq_disable_hazard();
+ if (c0_compare_int_pending())
+ return 0;
+
+ /*
+ * Feels like a real count / compare timer.
+ */
+ return 1;
+}
+
+void __cpuinit mips_clockevent_init(void)
+{
+ uint64_t mips_freq = mips_hpt_frequency;
+ unsigned int cpu = smp_processor_id();
+ struct clock_event_device *cd;
+ unsigned int irq = MIPS_CPU_IRQ_BASE + 7;
+
+ if (!cpu_has_counter)
+ return;
+
+#ifdef CONFIG_MIPS_MT_SMTC
+ setup_smtc_dummy_clockevent_device();
+
+ /*
+ * On SMTC we only register VPE0's compare interrupt as clockevent
+ * device.
+ */
+ if (cpu)
+ return;
+#endif
+
+ if (!c0_compare_int_usable())
+ return;
+
+ cd = &per_cpu(mips_clockevent_device, cpu);
+
+ cd->name = "MIPS";
+ cd->features = CLOCK_EVT_FEAT_ONESHOT;
+
+ /* Calculate the min / max delta */
+ cd->mult = div_sc((unsigned long) mips_freq, NSEC_PER_SEC, 32);
+ cd->shift = 32;
+ cd->max_delta_ns = clockevent_delta2ns(0x7fffffff, cd);
+ cd->min_delta_ns = clockevent_delta2ns(0x300, cd);
+
+ cd->rating = 300;
+ cd->irq = irq;
+#ifdef CONFIG_MIPS_MT_SMTC
+ cd->cpumask = CPU_MASK_ALL;
+#else
+ cd->cpumask = cpumask_of_cpu(cpu);
+#endif
+ cd->set_next_event = mips_next_event;
+ cd->set_mode = mips_set_mode;
+ cd->event_handler = mips_event_handler;
+
+ clockevents_register_device(cd);
+
+ if (!cp0_timer_irq_installed) {
+#ifdef CONFIG_MIPS_MT_SMTC
+#define CPUCTR_IMASKBIT (0x100 << cp0_compare_irq)
+ setup_irq_smtc(irq, &c0_compare_irqaction, CPUCTR_IMASKBIT);
+#else
+ setup_irq(irq, &c0_compare_irqaction);
+#endif /* CONFIG_MIPS_MT_SMTC */
+ cp0_timer_irq_installed = 1;
+ }
+}