arm: Fix warning in CORENPDQR code
[linux-3.10.git] / arch / arm / kernel / arch_timer.c
index dd58035..59dcdce 100644 (file)
  * published by the Free Software Foundation.
  */
 #include <linux/init.h>
-#include <linux/kernel.h>
-#include <linux/delay.h>
-#include <linux/device.h>
-#include <linux/smp.h>
-#include <linux/cpu.h>
-#include <linux/jiffies.h>
-#include <linux/clockchips.h>
-#include <linux/interrupt.h>
-#include <linux/of_irq.h>
-#include <linux/io.h>
+#include <linux/types.h>
+#include <linux/errno.h>
 
-#include <asm/cputype.h>
-#include <asm/localtimer.h>
-#include <asm/arch_timer.h>
-#include <asm/system_info.h>
+#include <asm/delay.h>
 #include <asm/sched_clock.h>
 
-static unsigned long arch_timer_rate;
-static int arch_timer_ppi;
-static int arch_timer_ppi2;
+#include <clocksource/arm_arch_timer.h>
 
-static struct clock_event_device __percpu **arch_timer_evt;
-
-/*
- * Architected system timer support.
- */
-
-#define ARCH_TIMER_CTRL_ENABLE         (1 << 0)
-#define ARCH_TIMER_CTRL_IT_MASK                (1 << 1)
-#define ARCH_TIMER_CTRL_IT_STAT                (1 << 2)
-
-#define ARCH_TIMER_REG_CTRL            0
-#define ARCH_TIMER_REG_FREQ            1
-#define ARCH_TIMER_REG_TVAL            2
-
-static void arch_timer_reg_write(int reg, u32 val)
-{
-       switch (reg) {
-       case ARCH_TIMER_REG_CTRL:
-               asm volatile("mcr p15, 0, %0, c14, c2, 1" : : "r" (val));
-               break;
-       case ARCH_TIMER_REG_TVAL:
-               asm volatile("mcr p15, 0, %0, c14, c2, 0" : : "r" (val));
-               break;
-       }
-
-       isb();
-}
-
-static u32 arch_timer_reg_read(int reg)
-{
-       u32 val;
-
-       switch (reg) {
-       case ARCH_TIMER_REG_CTRL:
-               asm volatile("mrc p15, 0, %0, c14, c2, 1" : "=r" (val));
-               break;
-       case ARCH_TIMER_REG_FREQ:
-               asm volatile("mrc p15, 0, %0, c14, c0, 0" : "=r" (val));
-               break;
-       case ARCH_TIMER_REG_TVAL:
-               asm volatile("mrc p15, 0, %0, c14, c2, 0" : "=r" (val));
-               break;
-       default:
-               BUG();
-       }
-
-       return val;
-}
-
-static irqreturn_t arch_timer_handler(int irq, void *dev_id)
+static unsigned long arch_timer_read_counter_long(void)
 {
-       struct clock_event_device *evt = *(struct clock_event_device **)dev_id;
-       unsigned long ctrl;
-
-       ctrl = arch_timer_reg_read(ARCH_TIMER_REG_CTRL);
-       if (ctrl & ARCH_TIMER_CTRL_IT_STAT) {
-               ctrl |= ARCH_TIMER_CTRL_IT_MASK;
-               arch_timer_reg_write(ARCH_TIMER_REG_CTRL, ctrl);
-               evt->event_handler(evt);
-               return IRQ_HANDLED;
-       }
-
-       return IRQ_NONE;
+       return arch_timer_read_counter();
 }
 
-static void arch_timer_disable(void)
-{
-       unsigned long ctrl;
-
-       ctrl = arch_timer_reg_read(ARCH_TIMER_REG_CTRL);
-       ctrl &= ~ARCH_TIMER_CTRL_ENABLE;
-       arch_timer_reg_write(ARCH_TIMER_REG_CTRL, ctrl);
-}
-
-static void arch_timer_set_mode(enum clock_event_mode mode,
-                               struct clock_event_device *clk)
-{
-       switch (mode) {
-       case CLOCK_EVT_MODE_UNUSED:
-       case CLOCK_EVT_MODE_SHUTDOWN:
-               arch_timer_disable();
-               break;
-       default:
-               break;
-       }
-}
+static u32 sched_clock_mult __read_mostly;
 
-static int arch_timer_set_next_event(unsigned long evt,
-                                    struct clock_event_device *unused)
+static unsigned long long notrace arch_timer_sched_clock(void)
 {
-       unsigned long ctrl;
-
-       ctrl = arch_timer_reg_read(ARCH_TIMER_REG_CTRL);
-       ctrl |= ARCH_TIMER_CTRL_ENABLE;
-       ctrl &= ~ARCH_TIMER_CTRL_IT_MASK;
-
-       arch_timer_reg_write(ARCH_TIMER_REG_TVAL, evt);
-       arch_timer_reg_write(ARCH_TIMER_REG_CTRL, ctrl);
-
-       return 0;
+       return arch_timer_read_counter() * sched_clock_mult;
 }
 
-static int __cpuinit arch_timer_setup(struct clock_event_device *clk)
-{
-       /* Be safe... */
-       arch_timer_disable();
-
-       clk->features = CLOCK_EVT_FEAT_ONESHOT;
-       clk->name = "arch_sys_timer";
-       clk->rating = 450;
-       clk->set_mode = arch_timer_set_mode;
-       clk->set_next_event = arch_timer_set_next_event;
-       clk->irq = arch_timer_ppi;
-
-       clockevents_config_and_register(clk, arch_timer_rate,
-                                       0xf, 0x7fffffff);
-
-       *__this_cpu_ptr(arch_timer_evt) = clk;
-
-       enable_percpu_irq(clk->irq, 0);
-       if (arch_timer_ppi2)
-               enable_percpu_irq(arch_timer_ppi2, 0);
-
-       return 0;
-}
+static struct delay_timer arch_delay_timer;
 
-/* Is the optional system timer available? */
-static int local_timer_is_architected(void)
+static void __init arch_timer_delay_timer_register(void)
 {
-       return (cpu_architecture() >= CPU_ARCH_ARMv7) &&
-              ((read_cpuid_ext(CPUID_EXT_PFR1) >> 16) & 0xf) == 1;
+       /* Use the architected timer for the delay loop. */
+       arch_delay_timer.read_current_timer = arch_timer_read_counter_long;
+       arch_delay_timer.freq = arch_timer_get_rate();
+       register_current_timer_delay(&arch_delay_timer);
 }
 
-static int arch_timer_available(void)
+int __init arch_timer_arch_init(void)
 {
-       unsigned long freq;
+        u32 arch_timer_rate = arch_timer_get_rate();
 
-       if (!local_timer_is_architected())
+       if (arch_timer_rate == 0)
                return -ENXIO;
 
-       if (arch_timer_rate == 0) {
-               arch_timer_reg_write(ARCH_TIMER_REG_CTRL, 0);
-               freq = arch_timer_reg_read(ARCH_TIMER_REG_FREQ);
-
-               /* Check the timer frequency. */
-               if (freq == 0) {
-                       pr_warn("Architected timer frequency not available\n");
-                       return -EINVAL;
-               }
-
-               arch_timer_rate = freq;
-       }
-
-       pr_info_once("Architected local timer running at %lu.%02luMHz.\n",
-                    arch_timer_rate / 1000000, (arch_timer_rate / 10000) % 100);
-       return 0;
-}
-
-static inline cycle_t arch_counter_get_cntpct(void)
-{
-       u32 cvall, cvalh;
-
-       asm volatile("mrrc p15, 0, %0, %1, c14" : "=r" (cvall), "=r" (cvalh));
-
-       return ((cycle_t) cvalh << 32) | cvall;
-}
-
-static inline cycle_t arch_counter_get_cntvct(void)
-{
-       u32 cvall, cvalh;
-
-       asm volatile("mrrc p15, 1, %0, %1, c14" : "=r" (cvall), "=r" (cvalh));
-
-       return ((cycle_t) cvalh << 32) | cvall;
-}
-
-static u32 notrace arch_counter_get_cntvct32(void)
-{
-       cycle_t cntvct = arch_counter_get_cntvct();
-
-       /*
-        * The sched_clock infrastructure only knows about counters
-        * with at most 32bits. Forget about the upper 24 bits for the
-        * time being...
-        */
-       return (u32)(cntvct & (u32)~0);
-}
-
-static cycle_t arch_counter_read(struct clocksource *cs)
-{
-       return arch_counter_get_cntpct();
-}
-
-static struct clocksource clocksource_counter = {
-       .name   = "arch_sys_counter",
-       .rating = 400,
-       .read   = arch_counter_read,
-       .mask   = CLOCKSOURCE_MASK(56),
-       .flags  = CLOCK_SOURCE_IS_CONTINUOUS,
-};
-
-static void __cpuinit arch_timer_stop(struct clock_event_device *clk)
-{
-       pr_debug("arch_timer_teardown disable IRQ%d cpu #%d\n",
-                clk->irq, smp_processor_id());
-       disable_percpu_irq(clk->irq);
-       if (arch_timer_ppi2)
-               disable_percpu_irq(arch_timer_ppi2);
-       arch_timer_set_mode(CLOCK_EVT_MODE_UNUSED, clk);
-}
-
-static struct local_timer_ops arch_timer_ops __cpuinitdata = {
-       .setup  = arch_timer_setup,
-       .stop   = arch_timer_stop,
-};
-
-static struct clock_event_device arch_timer_global_evt;
-
-static int __init arch_timer_register(void)
-{
-       int err;
-
-       err = arch_timer_available();
-       if (err)
-               return err;
-
-       arch_timer_evt = alloc_percpu(struct clock_event_device *);
-       if (!arch_timer_evt)
-               return -ENOMEM;
-
-       clocksource_register_hz(&clocksource_counter, arch_timer_rate);
-
-       err = request_percpu_irq(arch_timer_ppi, arch_timer_handler,
-                                "arch_timer", arch_timer_evt);
-       if (err) {
-               pr_err("arch_timer: can't register interrupt %d (%d)\n",
-                      arch_timer_ppi, err);
-               goto out_free;
-       }
-
-       if (arch_timer_ppi2) {
-               err = request_percpu_irq(arch_timer_ppi2, arch_timer_handler,
-                                        "arch_timer", arch_timer_evt);
-               if (err) {
-                       pr_err("arch_timer: can't register interrupt %d (%d)\n",
-                              arch_timer_ppi2, err);
-                       arch_timer_ppi2 = 0;
-                       goto out_free_irq;
-               }
-       }
-
-       err = local_timer_register(&arch_timer_ops);
-       if (err) {
-               /*
-                * We couldn't register as a local timer (could be
-                * because we're on a UP platform, or because some
-                * other local timer is already present...). Try as a
-                * global timer instead.
-                */
-               arch_timer_global_evt.cpumask = cpumask_of(0);
-               err = arch_timer_setup(&arch_timer_global_evt);
-       }
-
-       if (err)
-               goto out_free_irq;
-
-       return 0;
-
-out_free_irq:
-       free_percpu_irq(arch_timer_ppi, arch_timer_evt);
-       if (arch_timer_ppi2)
-               free_percpu_irq(arch_timer_ppi2, arch_timer_evt);
-
-out_free:
-       free_percpu(arch_timer_evt);
-
-       return err;
-}
-
-static const struct of_device_id arch_timer_of_match[] __initconst = {
-       { .compatible   = "arm,armv7-timer",    },
-       {},
-};
-
-int __init arch_timer_of_register(void)
-{
-       struct device_node *np;
-       u32 freq;
-
-       np = of_find_matching_node(NULL, arch_timer_of_match);
-       if (!np) {
-               pr_err("arch_timer: can't find DT node\n");
-               return -ENODEV;
-       }
-
-       /* Try to determine the frequency from the device tree or CNTFRQ */
-       if (!of_property_read_u32(np, "clock-frequency", &freq))
-               arch_timer_rate = freq;
-
-       arch_timer_ppi = irq_of_parse_and_map(np, 0);
-       arch_timer_ppi2 = irq_of_parse_and_map(np, 1);
-       pr_info("arch_timer: found %s irqs %d %d\n",
-               np->name, arch_timer_ppi, arch_timer_ppi2);
-
-       return arch_timer_register();
-}
-
-int __init arch_timer_sched_clock_init(void)
-{
-       int err;
+       arch_timer_delay_timer_register();
 
-       err = arch_timer_available();
-       if (err)
-               return err;
+       /* Cache the sched_clock multiplier to save a divide in the hot path. */
+       sched_clock_mult = NSEC_PER_SEC / arch_timer_rate;
+       sched_clock_func = arch_timer_sched_clock;
+       pr_info("sched_clock: ARM arch timer >56 bits at %ukHz, resolution %uns\n",
+               arch_timer_rate / 1000, sched_clock_mult);
 
-       setup_sched_clock(arch_counter_get_cntvct32, 32, arch_timer_rate);
        return 0;
 }