MN10300: Generic time support

Implement generic time support for MN10300.

Signed-off-by: Mark Salter <msalter@redhat.com>
Signed-off-by: David Howells <dhowells@redhat.com>

7 files changed, 268 insertions, 39 deletions

diff --git a/arch/mn10300/kernel/Makefile b/arch/mn10300/kernel/Makefile
index 5b41192f496b..8f5f1e81baf5 100644
--- a/arch/mn10300/kernel/Makefile
+++ b/arch/mn10300/kernel/Makefile
@@ -28,3 +28,5 @@ obj-$(CONFIG_MN10300_RTC) += rtc.o
 obj-$(CONFIG_PROFILE) += profile.o profile-low.o
 obj-$(CONFIG_MODULES) += module.o
 obj-$(CONFIG_KPROBES) += kprobes.o
+obj-$(CONFIG_CSRC_MN10300) += csrc-mn10300.o
+obj-$(CONFIG_CEVT_MN10300) += cevt-mn10300.o
diff --git a/arch/mn10300/kernel/cevt-mn10300.c b/arch/mn10300/kernel/cevt-mn10300.c
new file mode 100644
index 000000000000..d4cb535bf786
--- /dev/null
+++ b/arch/mn10300/kernel/cevt-mn10300.c
@@ -0,0 +1,131 @@
+/* MN10300 clockevents
+ *
+ * Copyright (C) 2010 Red Hat, Inc. All Rights Reserved.
+ * Written by Mark Salter (msalter@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public Licence
+ * as published by the Free Software Foundation; either version
+ * 2 of the Licence, or (at your option) any later version.
+ */
+#include <linux/clockchips.h>
+#include <linux/interrupt.h>
+#include <linux/percpu.h>
+#include <linux/smp.h>
+#include <asm/timex.h>
+#include "internal.h"
+
+#ifdef CONFIG_SMP
+#if (CONFIG_NR_CPUS > 2) && !defined(CONFIG_GEENERIC_CLOCKEVENTS_BROADCAST)
+#error "This doesn't scale well! Need per-core local timers."
+#endif
+#else /* CONFIG_SMP */
+#define stop_jiffies_counter1()
+#define reload_jiffies_counter1(x)
+#define TMJC1IRQ TMJCIRQ
+#endif
+
+
+static int next_event(unsigned long delta,
+                      struct clock_event_device *evt)
+{
+        unsigned int cpu = smp_processor_id();
+
+        if (cpu == 0) {
+                stop_jiffies_counter();
+                reload_jiffies_counter(delta - 1);
+        } else {
+                stop_jiffies_counter1();
+                reload_jiffies_counter1(delta - 1);
+        }
+        return 0;
+}
+
+static void set_clock_mode(enum clock_event_mode mode,
+                           struct clock_event_device *evt)
+{
+        /* Nothing to do ...  */
+}
+
+static DEFINE_PER_CPU(struct clock_event_device, mn10300_clockevent_device);
+static DEFINE_PER_CPU(struct irqaction, timer_irq);
+
+static irqreturn_t timer_interrupt(int irq, void *dev_id)
+{
+        struct clock_event_device *cd;
+        unsigned int cpu = smp_processor_id();
+
+        if (cpu == 0)
+                stop_jiffies_counter();
+        else
+                stop_jiffies_counter1();
+
+        cd = &per_cpu(mn10300_clockevent_device, cpu);
+        cd->event_handler(cd);
+
+        return IRQ_HANDLED;
+}
+
+static void event_handler(struct clock_event_device *dev)
+{
+}
+
+int __init init_clockevents(void)
+{
+        struct clock_event_device *cd;
+        struct irqaction *iact;
+        unsigned int cpu = smp_processor_id();
+
+        cd = &per_cpu(mn10300_clockevent_device, cpu);
+
+        if (cpu == 0) {
+                stop_jiffies_counter();
+                cd->irq = TMJCIRQ;
+        } else {
+                stop_jiffies_counter1();
+                cd->irq = TMJC1IRQ;
+        }
+
+        cd->name                = "Timestamp";
+        cd->features            = CLOCK_EVT_FEAT_ONESHOT;
+
+        /* Calculate the min / max delta */
+        clockevent_set_clock(cd, MN10300_JCCLK);
+
+        cd->max_delta_ns        = clockevent_delta2ns(TMJCBR_MAX, cd);
+        cd->min_delta_ns        = clockevent_delta2ns(100, cd);
+
+        cd->rating              = 200;
+        cd->cpumask             = cpumask_of(smp_processor_id());
+        cd->set_mode            = set_clock_mode;
+        cd->event_handler       = event_handler;
+        cd->set_next_event      = next_event;
+
+        iact = &per_cpu(timer_irq, cpu);
+        iact->flags = IRQF_DISABLED | IRQF_SHARED | IRQF_TIMER;
+        iact->handler = timer_interrupt;
+
+        clockevents_register_device(cd);
+
+#if defined(CONFIG_SMP) && !defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST)
+        /* setup timer irq affinity so it only runs on this cpu */
+        {
+                struct irq_desc *desc;
+                desc = irq_to_desc(cd->irq);
+                cpumask_copy(desc->affinity, cpumask_of(cpu));
+                iact->flags |= IRQF_NOBALANCING;
+        }
+#endif
+
+        if (cpu == 0) {
+                reload_jiffies_counter(MN10300_JC_PER_HZ - 1);
+                iact->name = "CPU0 Timer";
+        } else {
+                reload_jiffies_counter1(MN10300_JC_PER_HZ - 1);
+                iact->name = "CPU1 Timer";
+        }
+
+        setup_jiffies_interrupt(cd->irq, iact);
+
+        return 0;
+}
diff --git a/arch/mn10300/kernel/csrc-mn10300.c b/arch/mn10300/kernel/csrc-mn10300.c
new file mode 100644
index 000000000000..ba2f0c4d6e01
--- /dev/null
+++ b/arch/mn10300/kernel/csrc-mn10300.c
@@ -0,0 +1,35 @@
+/* MN10300 clocksource
+ *
+ * Copyright (C) 2010 Red Hat, Inc. All Rights Reserved.
+ * Written by Mark Salter (msalter@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public Licence
+ * as published by the Free Software Foundation; either version
+ * 2 of the Licence, or (at your option) any later version.
+ */
+#include <linux/clocksource.h>
+#include <linux/init.h>
+#include <asm/timex.h>
+#include "internal.h"
+
+static cycle_t mn10300_read(struct clocksource *cs)
+{
+        return read_timestamp_counter();
+}
+
+static struct clocksource clocksource_mn10300 = {
+        .name   = "TSC",
+        .rating = 200,
+        .read   = mn10300_read,
+        .mask   = CLOCKSOURCE_MASK(32),
+        .flags  = CLOCK_SOURCE_IS_CONTINUOUS,
+};
+
+int __init init_clocksource(void)
+{
+        startup_timestamp_counter();
+        clocksource_set_clock(&clocksource_mn10300, MN10300_TSCCLK);
+        clocksource_register(&clocksource_mn10300);
+        return 0;
+}
diff --git a/arch/mn10300/kernel/internal.h b/arch/mn10300/kernel/internal.h
index 3b1f48b7e7f4..6a064ab5af07 100644
--- a/arch/mn10300/kernel/internal.h
+++ b/arch/mn10300/kernel/internal.h
@@ -9,6 +9,9 @@
  * 2 of the Licence, or (at your option) any later version.
  */
 
+struct clocksource;
+struct clock_event_device;
+
 /*
  * kthread.S
  */
@@ -30,3 +33,13 @@ extern void mn10300_low_ipi_handler(void);
  * time.c
  */
 extern irqreturn_t local_timer_interrupt(void);
+
+/*
+ * time.c
+ */
+#ifdef CONFIG_CEVT_MN10300
+extern void clockevent_set_clock(struct clock_event_device *, unsigned int);
+#endif
+#ifdef CONFIG_CSRC_MN10300
+extern void clocksource_set_clock(struct clocksource *, unsigned int);
+#endif
diff --git a/arch/mn10300/kernel/irq.c b/arch/mn10300/kernel/irq.c
index 80f15725ecad..2f66a45dcd18 100644
--- a/arch/mn10300/kernel/irq.c
+++ b/arch/mn10300/kernel/irq.c
@@ -16,14 +16,6 @@
 #include <asm/setup.h>
 #include <asm/serial-regs.h>
 
-#ifdef CONFIG_SMP
-#undef  GxICR
-#define GxICR(X) CROSS_GxICR(X, irq_affinity_online[X])
-
-#undef  GxICR_u8
-#define GxICR_u8(X) CROSS_GxICR_u8(X, irq_affinity_online[X])
-#endif /* CONFIG_SMP */
-
 unsigned long __mn10300_irq_enabled_epsw[NR_CPUS] __cacheline_aligned_in_smp = {
         [0 ... NR_CPUS - 1] = EPSW_IE | EPSW_IM_7
 };
@@ -92,9 +84,11 @@ static void mn10300_cpupic_mask_ack(unsigned int irq)
                 GxICR(irq) = (tmp & GxICR_LEVEL);
                 tmp2 = GxICR(irq);
 
-                irq_affinity_online[irq] = any_online_cpu(*irq_desc[irq].affinity);
-                GxICR(irq) = (tmp & (GxICR_LEVEL | GxICR_ENABLE)) | GxICR_DETECT;
-                tmp = GxICR(irq);
+                irq_affinity_online[irq] =
+                        any_online_cpu(*irq_desc[irq].affinity);
+                CROSS_GxICR(irq, irq_affinity_online[irq]) =
+                        (tmp & (GxICR_LEVEL | GxICR_ENABLE)) | GxICR_DETECT;
+                tmp = CROSS_GxICR(irq, irq_affinity_online[irq]);
         }
 
         arch_local_irq_restore(flags);
@@ -128,8 +122,8 @@ static void mn10300_cpupic_unmask_clear(unsigned int irq)
                 tmp = GxICR(irq);
 
                 irq_affinity_online[irq] = any_online_cpu(*irq_desc[irq].affinity);
-                GxICR(irq) = (tmp & GxICR_LEVEL) | GxICR_ENABLE | GxICR_DETECT;
-                tmp = GxICR(irq);
+                CROSS_GxICR(irq, irq_affinity_online[irq]) = (tmp & GxICR_LEVEL) | GxICR_ENABLE | GxICR_DETECT;
+                tmp = CROSS_GxICR(irq, irq_affinity_online[irq]);
         }
 
         arch_local_irq_restore(flags);
@@ -217,7 +211,7 @@ static struct irq_chip mn10300_cpu_pic_level = {
         .unmask         = mn10300_cpupic_unmask_clear,
 #ifdef CONFIG_SMP
         .set_affinity   = mn10300_cpupic_setaffinity,
-#endif /* CONFIG_SMP */
+#endif
 };
 
 /*
@@ -235,7 +229,7 @@ static struct irq_chip mn10300_cpu_pic_edge = {
         .unmask         = mn10300_cpupic_unmask,
 #ifdef CONFIG_SMP
         .set_affinity   = mn10300_cpupic_setaffinity,
-#endif /* CONFIG_SMP */
+#endif
 };
 
 /*
@@ -446,9 +440,9 @@ void migrate_irqs(void)
                 if (irq_affinity_online[irq] == self) {
                         u16 x, tmp;
 
-                        x = CROSS_GxICR(irq, self);
-                        CROSS_GxICR(irq, self) = x & GxICR_LEVEL;
-                        tmp = CROSS_GxICR(irq, self);
+                        x = GxICR(irq);
+                        GxICR(irq) = x & GxICR_LEVEL;
+                        tmp = GxICR(irq);
 
                         new = any_online_cpu(irq_desc[irq].affinity);
                         irq_affinity_online[irq] = new;
@@ -458,7 +452,7 @@ void migrate_irqs(void)
                         tmp = CROSS_GxICR(irq, new);
 
                         x &= GxICR_LEVEL | GxICR_ENABLE;
-                        if (CROSS_GxICR(irq, self) & GxICR_REQUEST)
+                        if (GxICR(irq) & GxICR_REQUEST) {
                                 x |= GxICR_REQUEST | GxICR_DETECT;
                         CROSS_GxICR(irq, new) = x;
                         tmp = CROSS_GxICR(irq, new);
diff --git a/arch/mn10300/kernel/smp.c b/arch/mn10300/kernel/smp.c
index b80234c28e0d..0dcd1c686ba8 100644
--- a/arch/mn10300/kernel/smp.c
+++ b/arch/mn10300/kernel/smp.c
@@ -126,7 +126,6 @@ static struct irq_chip mn10300_ipi_type = {
 
 static irqreturn_t smp_reschedule_interrupt(int irq, void *dev_id);
 static irqreturn_t smp_call_function_interrupt(int irq, void *dev_id);
-static irqreturn_t smp_ipi_timer_interrupt(int irq, void *dev_id);
 
 static struct irqaction reschedule_ipi = {
         .handler        = smp_reschedule_interrupt,
@@ -136,11 +135,15 @@ static struct irqaction call_function_ipi = {
         .handler        = smp_call_function_interrupt,
         .name           = "smp call function IPI"
 };
+
+#if !defined(CONFIG_GENERIC_CLOCKEVENTS) || defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST)
+static irqreturn_t smp_ipi_timer_interrupt(int irq, void *dev_id);
 static struct irqaction local_timer_ipi = {
         .handler        = smp_ipi_timer_interrupt,
         .flags          = IRQF_DISABLED,
         .name           = "smp local timer IPI"
 };
+#endif
 
 /**
  * init_ipi - Initialise the IPI mechanism
@@ -165,11 +168,14 @@ static void init_ipi(void)
         mn10300_ipi_enable(CALL_FUNC_SINGLE_IPI);
 
         /* set up the local timer IPI */
+#if !defined(CONFIG_GENERIC_CLOCKEVENTS) || \
+    defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST)
         set_irq_chip_and_handler(LOCAL_TIMER_IPI,
                                  &mn10300_ipi_type, handle_percpu_irq);
         setup_irq(LOCAL_TIMER_IPI, &local_timer_ipi);
         set_intr_level(LOCAL_TIMER_IPI, LOCAL_TIMER_GxICR_LV);
         mn10300_ipi_enable(LOCAL_TIMER_IPI);
+#endif
 
 #ifdef CONFIG_MN10300_CACHE_ENABLED
         /* set up the cache flush IPI */
@@ -505,6 +511,8 @@ void smp_nmi_call_function_interrupt(void)
         }
 }
 
+#if !defined(CONFIG_GENERIC_CLOCKEVENTS) || \
+    defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST)
 /**
  * smp_ipi_timer_interrupt - Local timer IPI handler
  * @irq: The interrupt number.
@@ -516,6 +524,7 @@ static irqreturn_t smp_ipi_timer_interrupt(int irq, void *dev_id)
 {
         return local_timer_interrupt();
 }
+#endif
 
 void __init smp_init_cpus(void)
 {
@@ -620,7 +629,6 @@ void smp_prepare_cpu_init(void)
 int __init start_secondary(void *unused)
 {
         smp_cpu_init();
-
         smp_callin();
         while (!cpu_isset(smp_processor_id(), smp_commenced_mask))
                 cpu_relax();
@@ -629,6 +637,9 @@ int __init start_secondary(void *unused)
         preempt_disable();
         smp_online();
 
+#ifdef CONFIG_GENERIC_CLOCKEVENTS
+        init_clockevents();
+#endif
         cpu_idle();
         return 0;
 }
diff --git a/arch/mn10300/kernel/time.c b/arch/mn10300/kernel/time.c
index 0cb9bdb3b6bd..f860a340acc9 100644
--- a/arch/mn10300/kernel/time.c
+++ b/arch/mn10300/kernel/time.c
@@ -17,6 +17,8 @@
 #include <linux/smp.h>
 #include <linux/profile.h>
 #include <linux/cnt32_to_63.h>
+#include <linux/clocksource.h>
+#include <linux/clockchips.h>
 #include <asm/irq.h>
 #include <asm/div64.h>
 #include <asm/processor.h>
@@ -27,14 +29,6 @@
 static unsigned long mn10300_last_tsc;  /* time-stamp counter at last time
                                          * interrupt occurred */
 
-static irqreturn_t timer_interrupt(int irq, void *dev_id);
-
-static struct irqaction timer_irq = {
-        .handler        = timer_interrupt,
-        .flags          = IRQF_DISABLED | IRQF_SHARED | IRQF_TIMER,
-        .name           = "timer",
-};
-
 static unsigned long sched_clock_multiplier;
 
 /*
@@ -54,7 +48,7 @@ unsigned long long sched_clock(void)
 
         /* read the TSC value
          */
-        tsc = 0 - get_cycles(); /* get_cycles() counts down */
+        tsc = get_cycles();
 
         /* expand to 64-bits.
          * - sched_clock() must be called once a minute or better or the
@@ -103,6 +97,7 @@ irqreturn_t local_timer_interrupt(void)
         return IRQ_HANDLED;
 }
 
+#ifndef CONFIG_GENERIC_TIME
 /*
  * advance the kernel's time keeping clocks (xtime and jiffies)
  * - we use Timer 0 & 1 cascaded as a clock to nudge us the next time
@@ -116,11 +111,11 @@ static irqreturn_t timer_interrupt(int irq, void *dev_id)
         write_seqlock(&xtime_lock);
 
         while (tsc = get_cycles(),
-               elapse = mn10300_last_tsc - tsc, /* time elapsed since last
+               elapse = tsc - mn10300_last_tsc, /* time elapsed since last
                                                  * tick */
                elapse > MN10300_TSC_PER_HZ
                ) {
-                mn10300_last_tsc -= MN10300_TSC_PER_HZ;
+                mn10300_last_tsc += MN10300_TSC_PER_HZ;
 
                 /* advance the kernel's time tracking system */
                 do_timer(1);
@@ -135,6 +130,50 @@ static irqreturn_t timer_interrupt(int irq, void *dev_id)
         return ret;
 }
 
+static struct irqaction timer_irq = {
+        .handler        = timer_interrupt,
+        .flags          = IRQF_DISABLED | IRQF_SHARED | IRQF_TIMER,
+        .name           = "timer",
+};
+#endif /* CONFIG_GENERIC_TIME */
+
+#ifdef CONFIG_CSRC_MN10300
+void __init clocksource_set_clock(struct clocksource *cs, unsigned int clock)
+{
+        u64 temp;
+        u32 shift;
+
+        /* Find a shift value */
+        for (shift = 32; shift > 0; shift--) {
+                temp = (u64) NSEC_PER_SEC << shift;
+                do_div(temp, clock);
+                if ((temp >> 32) == 0)
+                        break;
+        }
+        cs->shift = shift;
+        cs->mult = (u32) temp;
+}
+#endif
+
+#if CONFIG_CEVT_MN10300
+void __cpuinit clockevent_set_clock(struct clock_event_device *cd,
+                                    unsigned int clock)
+{
+        u64 temp;
+        u32 shift;
+
+        /* Find a shift value */
+        for (shift = 32; shift > 0; shift--) {
+                temp = (u64) clock << shift;
+                do_div(temp, NSEC_PER_SEC);
+                if ((temp >> 32) == 0)
+                        break;
+        }
+        cd->shift = shift;
+        cd->mult = (u32) temp;
+}
+#endif
+
 /*
  * initialise the various timers used by the main part of the kernel
  */
@@ -146,21 +185,25 @@ void __init time_init(void)
          */
         TMPSCNT |= TMPSCNT_ENABLE;
 
+#ifdef CONFIG_GENERIC_TIME
+        init_clocksource();
+#else
         startup_timestamp_counter();
+#endif
 
         printk(KERN_INFO
                "timestamp counter I/O clock running at %lu.%02lu"
                " (calibrated against RTC)\n",
                MN10300_TSCCLK / 1000000, (MN10300_TSCCLK / 10000) % 100);
 
-        mn10300_last_tsc = TMTSCBC;
+        mn10300_last_tsc = read_timestamp_counter();
 
-        /* use timer 0 & 1 cascaded to tick at as close to HZ as possible */
-        setup_irq(TMJCIRQ, &timer_irq);
-
-        set_intr_level(TMJCIRQ, NUM2GxICR_LEVEL(CONFIG_TIMER_IRQ_LEVEL));
-
-        startup_jiffies_counter();
+#ifdef CONFIG_GENERIC_CLOCKEVENTS
+        init_clockevents();
+#else
+        reload_jiffies_counter(MN10300_JC_PER_HZ - 1);
+        setup_jiffies_interrupt(TMJCIRQ, &timer_irq, CONFIG_TIMER_IRQ_LEVEL);
+#endif
 
 #ifdef CONFIG_MN10300_WD_TIMER
         /* start the watchdog timer */