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-rw-r--r--arch/arm/include/asm/arch_timer.h8
-rw-r--r--arch/arm/include/asm/delay.h9
-rw-r--r--arch/arm/include/asm/timex.h6
-rw-r--r--arch/arm/kernel/arch_timer.c383
-rw-r--r--arch/arm/lib/delay.c35
5 files changed, 316 insertions, 125 deletions
diff --git a/arch/arm/include/asm/arch_timer.h b/arch/arm/include/asm/arch_timer.h
index 62e7547..d40229d 100644
--- a/arch/arm/include/asm/arch_timer.h
+++ b/arch/arm/include/asm/arch_timer.h
@@ -2,11 +2,12 @@
#define __ASMARM_ARCH_TIMER_H
#include <asm/errno.h>
+#include <linux/clocksource.h>
#ifdef CONFIG_ARM_ARCH_TIMER
-#define ARCH_HAS_READ_CURRENT_TIMER
int arch_timer_of_register(void);
int arch_timer_sched_clock_init(void);
+struct timecounter *arch_timer_get_timecounter(void);
#else
static inline int arch_timer_of_register(void)
{
@@ -17,6 +18,11 @@ static inline int arch_timer_sched_clock_init(void)
{
return -ENXIO;
}
+
+static inline struct timecounter *arch_timer_get_timecounter(void)
+{
+ return NULL;
+}
#endif
#endif
diff --git a/arch/arm/include/asm/delay.h b/arch/arm/include/asm/delay.h
index dc61451..ab98fdd 100644
--- a/arch/arm/include/asm/delay.h
+++ b/arch/arm/include/asm/delay.h
@@ -15,6 +15,11 @@
#ifndef __ASSEMBLY__
+struct delay_timer {
+ unsigned long (*read_current_timer)(void);
+ unsigned long freq;
+};
+
extern struct arm_delay_ops {
void (*delay)(unsigned long);
void (*const_udelay)(unsigned long);
@@ -56,6 +61,10 @@ extern void __loop_delay(unsigned long loops);
extern void __loop_udelay(unsigned long usecs);
extern void __loop_const_udelay(unsigned long);
+/* Delay-loop timer registration. */
+#define ARCH_HAS_READ_CURRENT_TIMER
+extern void register_current_timer_delay(const struct delay_timer *timer);
+
#endif /* __ASSEMBLY__ */
#endif /* defined(_ARM_DELAY_H) */
diff --git a/arch/arm/include/asm/timex.h b/arch/arm/include/asm/timex.h
index 5e71172..9acc135 100644
--- a/arch/arm/include/asm/timex.h
+++ b/arch/arm/include/asm/timex.h
@@ -12,13 +12,9 @@
#ifndef _ASMARM_TIMEX_H
#define _ASMARM_TIMEX_H
-#include <asm/arch_timer.h>
#include <mach/timex.h>
-#ifdef ARCH_HAS_READ_CURRENT_TIMER
+typedef unsigned long cycles_t;
#define get_cycles() ({ cycles_t c; read_current_timer(&c) ? 0 : c; })
-#endif
-
-#include <asm-generic/timex.h>
#endif
diff --git a/arch/arm/kernel/arch_timer.c b/arch/arm/kernel/arch_timer.c
index cf25880..c8ef207 100644
--- a/arch/arm/kernel/arch_timer.c
+++ b/arch/arm/kernel/arch_timer.c
@@ -21,18 +21,28 @@
#include <linux/io.h>
#include <asm/cputype.h>
+#include <asm/delay.h>
#include <asm/localtimer.h>
#include <asm/arch_timer.h>
#include <asm/system_info.h>
#include <asm/sched_clock.h>
static unsigned long arch_timer_rate;
-static int arch_timer_ppi;
-static int arch_timer_ppi2;
+
+enum ppi_nr {
+ PHYS_SECURE_PPI,
+ PHYS_NONSECURE_PPI,
+ VIRT_PPI,
+ HYP_PPI,
+ MAX_TIMER_PPI
+};
+
+static int arch_timer_ppi[MAX_TIMER_PPI];
static struct clock_event_device __percpu **arch_timer_evt;
+static struct delay_timer arch_delay_timer;
-extern void init_current_timer_delay(unsigned long freq);
+static bool arch_timer_use_virtual = true;
/*
* Architected system timer support.
@@ -46,50 +56,104 @@ extern void init_current_timer_delay(unsigned long freq);
#define ARCH_TIMER_REG_FREQ 1
#define ARCH_TIMER_REG_TVAL 2
-static void arch_timer_reg_write(int reg, u32 val)
+#define ARCH_TIMER_PHYS_ACCESS 0
+#define ARCH_TIMER_VIRT_ACCESS 1
+
+/*
+ * These register accessors are marked inline so the compiler can
+ * nicely work out which register we want, and chuck away the rest of
+ * the code. At least it does so with a recent GCC (4.6.3).
+ */
+static inline void arch_timer_reg_write(const int access, const 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;
+ if (access == ARCH_TIMER_PHYS_ACCESS) {
+ 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;
+ }
+ }
+
+ if (access == ARCH_TIMER_VIRT_ACCESS) {
+ switch (reg) {
+ case ARCH_TIMER_REG_CTRL:
+ asm volatile("mcr p15, 0, %0, c14, c3, 1" : : "r" (val));
+ break;
+ case ARCH_TIMER_REG_TVAL:
+ asm volatile("mcr p15, 0, %0, c14, c3, 0" : : "r" (val));
+ break;
+ }
}
isb();
}
-static u32 arch_timer_reg_read(int reg)
+static inline u32 arch_timer_reg_read(const int access, const int reg)
{
- u32 val;
+ u32 val = 0;
+
+ if (access == ARCH_TIMER_PHYS_ACCESS) {
+ switch (reg) {
+ case ARCH_TIMER_REG_CTRL:
+ asm volatile("mrc p15, 0, %0, c14, c2, 1" : "=r" (val));
+ break;
+ case ARCH_TIMER_REG_TVAL:
+ asm volatile("mrc p15, 0, %0, c14, c2, 0" : "=r" (val));
+ break;
+ case ARCH_TIMER_REG_FREQ:
+ asm volatile("mrc p15, 0, %0, c14, c0, 0" : "=r" (val));
+ break;
+ }
+ }
- 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();
+ if (access == ARCH_TIMER_VIRT_ACCESS) {
+ switch (reg) {
+ case ARCH_TIMER_REG_CTRL:
+ asm volatile("mrc p15, 0, %0, c14, c3, 1" : "=r" (val));
+ break;
+ case ARCH_TIMER_REG_TVAL:
+ asm volatile("mrc p15, 0, %0, c14, c3, 0" : "=r" (val));
+ break;
+ }
}
return val;
}
-static irqreturn_t arch_timer_handler(int irq, void *dev_id)
+static inline cycle_t arch_timer_counter_read(const int access)
{
- struct clock_event_device *evt = *(struct clock_event_device **)dev_id;
- unsigned long ctrl;
+ cycle_t cval = 0;
+
+ if (access == ARCH_TIMER_PHYS_ACCESS)
+ asm volatile("mrrc p15, 0, %Q0, %R0, c14" : "=r" (cval));
+
+ if (access == ARCH_TIMER_VIRT_ACCESS)
+ asm volatile("mrrc p15, 1, %Q0, %R0, c14" : "=r" (cval));
+
+ return cval;
+}
+
+static inline cycle_t arch_counter_get_cntpct(void)
+{
+ return arch_timer_counter_read(ARCH_TIMER_PHYS_ACCESS);
+}
- ctrl = arch_timer_reg_read(ARCH_TIMER_REG_CTRL);
+static inline cycle_t arch_counter_get_cntvct(void)
+{
+ return arch_timer_counter_read(ARCH_TIMER_VIRT_ACCESS);
+}
+
+static irqreturn_t inline timer_handler(const int access,
+ struct clock_event_device *evt)
+{
+ unsigned long ctrl;
+ ctrl = arch_timer_reg_read(access, 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);
+ arch_timer_reg_write(access, ARCH_TIMER_REG_CTRL, ctrl);
evt->event_handler(evt);
return IRQ_HANDLED;
}
@@ -97,63 +161,100 @@ static irqreturn_t arch_timer_handler(int irq, void *dev_id)
return IRQ_NONE;
}
-static void arch_timer_disable(void)
+static irqreturn_t arch_timer_handler_virt(int irq, void *dev_id)
{
- unsigned long ctrl;
+ struct clock_event_device *evt = *(struct clock_event_device **)dev_id;
- ctrl = arch_timer_reg_read(ARCH_TIMER_REG_CTRL);
- ctrl &= ~ARCH_TIMER_CTRL_ENABLE;
- arch_timer_reg_write(ARCH_TIMER_REG_CTRL, ctrl);
+ return timer_handler(ARCH_TIMER_VIRT_ACCESS, evt);
}
-static void arch_timer_set_mode(enum clock_event_mode mode,
- struct clock_event_device *clk)
+static irqreturn_t arch_timer_handler_phys(int irq, void *dev_id)
{
+ struct clock_event_device *evt = *(struct clock_event_device **)dev_id;
+
+ return timer_handler(ARCH_TIMER_PHYS_ACCESS, evt);
+}
+
+static inline void timer_set_mode(const int access, int mode)
+{
+ unsigned long ctrl;
switch (mode) {
case CLOCK_EVT_MODE_UNUSED:
case CLOCK_EVT_MODE_SHUTDOWN:
- arch_timer_disable();
+ ctrl = arch_timer_reg_read(access, ARCH_TIMER_REG_CTRL);
+ ctrl &= ~ARCH_TIMER_CTRL_ENABLE;
+ arch_timer_reg_write(access, ARCH_TIMER_REG_CTRL, ctrl);
break;
default:
break;
}
}
-static int arch_timer_set_next_event(unsigned long evt,
- struct clock_event_device *unused)
+static void arch_timer_set_mode_virt(enum clock_event_mode mode,
+ struct clock_event_device *clk)
{
- unsigned long ctrl;
+ timer_set_mode(ARCH_TIMER_VIRT_ACCESS, mode);
+}
- ctrl = arch_timer_reg_read(ARCH_TIMER_REG_CTRL);
+static void arch_timer_set_mode_phys(enum clock_event_mode mode,
+ struct clock_event_device *clk)
+{
+ timer_set_mode(ARCH_TIMER_PHYS_ACCESS, mode);
+}
+
+static inline void set_next_event(const int access, unsigned long evt)
+{
+ unsigned long ctrl;
+ ctrl = arch_timer_reg_read(access, ARCH_TIMER_REG_CTRL);
ctrl |= ARCH_TIMER_CTRL_ENABLE;
ctrl &= ~ARCH_TIMER_CTRL_IT_MASK;
+ arch_timer_reg_write(access, ARCH_TIMER_REG_TVAL, evt);
+ arch_timer_reg_write(access, ARCH_TIMER_REG_CTRL, ctrl);
+}
- arch_timer_reg_write(ARCH_TIMER_REG_TVAL, evt);
- arch_timer_reg_write(ARCH_TIMER_REG_CTRL, ctrl);
+static int arch_timer_set_next_event_virt(unsigned long evt,
+ struct clock_event_device *unused)
+{
+ set_next_event(ARCH_TIMER_VIRT_ACCESS, evt);
+ return 0;
+}
+static int arch_timer_set_next_event_phys(unsigned long evt,
+ struct clock_event_device *unused)
+{
+ set_next_event(ARCH_TIMER_PHYS_ACCESS, evt);
return 0;
}
static int __cpuinit arch_timer_setup(struct clock_event_device *clk)
{
- /* Be safe... */
- arch_timer_disable();
-
clk->features = CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_C3STOP;
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;
+ if (arch_timer_use_virtual) {
+ clk->irq = arch_timer_ppi[VIRT_PPI];
+ clk->set_mode = arch_timer_set_mode_virt;
+ clk->set_next_event = arch_timer_set_next_event_virt;
+ } else {
+ clk->irq = arch_timer_ppi[PHYS_SECURE_PPI];
+ clk->set_mode = arch_timer_set_mode_phys;
+ clk->set_next_event = arch_timer_set_next_event_phys;
+ }
+
+ clk->set_mode(CLOCK_EVT_MODE_SHUTDOWN, NULL);
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);
+ if (arch_timer_use_virtual)
+ enable_percpu_irq(arch_timer_ppi[VIRT_PPI], 0);
+ else {
+ enable_percpu_irq(arch_timer_ppi[PHYS_SECURE_PPI], 0);
+ if (arch_timer_ppi[PHYS_NONSECURE_PPI])
+ enable_percpu_irq(arch_timer_ppi[PHYS_NONSECURE_PPI], 0);
+ }
return 0;
}
@@ -173,8 +274,8 @@ static int arch_timer_available(void)
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);
+ freq = arch_timer_reg_read(ARCH_TIMER_PHYS_ACCESS,
+ ARCH_TIMER_REG_FREQ);
/* Check the timer frequency. */
if (freq == 0) {
@@ -185,52 +286,57 @@ static int arch_timer_available(void)
arch_timer_rate = freq;
}
- pr_info_once("Architected local timer running at %lu.%02luMHz.\n",
- arch_timer_rate / 1000000, (arch_timer_rate / 10000) % 100);
+ pr_info_once("Architected local timer running at %lu.%02luMHz (%s).\n",
+ arch_timer_rate / 1000000, (arch_timer_rate / 10000) % 100,
+ arch_timer_use_virtual ? "virt" : "phys");
return 0;
}
-static inline cycle_t arch_counter_get_cntpct(void)
+static u32 notrace arch_counter_get_cntpct32(void)
{
- u32 cvall, cvalh;
-
- asm volatile("mrrc p15, 0, %0, %1, c14" : "=r" (cvall), "=r" (cvalh));
+ cycle_t cnt = arch_counter_get_cntpct();
- 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;
+ /*
+ * The sched_clock infrastructure only knows about counters
+ * with at most 32bits. Forget about the upper 24 bits for the
+ * time being...
+ */
+ return (u32)cnt;
}
static u32 notrace arch_counter_get_cntvct32(void)
{
- cycle_t cntvct = arch_counter_get_cntvct();
+ cycle_t cnt = 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);
+ return (u32)cnt;
}
static cycle_t arch_counter_read(struct clocksource *cs)
{
+ /*
+ * Always use the physical counter for the clocksource.
+ * CNTHCTL.PL1PCTEN must be set to 1.
+ */
return arch_counter_get_cntpct();
}
-int read_current_timer(unsigned long *timer_val)
+static unsigned long arch_timer_read_current_timer(void)
{
- if (!arch_timer_rate)
- return -ENXIO;
- *timer_val = arch_counter_get_cntpct();
- return 0;
+ return arch_counter_get_cntpct();
+}
+
+static cycle_t arch_counter_read_cc(const struct cyclecounter *cc)
+{
+ /*
+ * Always use the physical counter for the clocksource.
+ * CNTHCTL.PL1PCTEN must be set to 1.
+ */
+ return arch_counter_get_cntpct();
}
static struct clocksource clocksource_counter = {
@@ -241,14 +347,32 @@ static struct clocksource clocksource_counter = {
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
};
+static struct cyclecounter cyclecounter = {
+ .read = arch_counter_read_cc,
+ .mask = CLOCKSOURCE_MASK(56),
+};
+
+static struct timecounter timecounter;
+
+struct timecounter *arch_timer_get_timecounter(void)
+{
+ return &timecounter;
+}
+
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);
+
+ if (arch_timer_use_virtual)
+ disable_percpu_irq(arch_timer_ppi[VIRT_PPI]);
+ else {
+ disable_percpu_irq(arch_timer_ppi[PHYS_SECURE_PPI]);
+ if (arch_timer_ppi[PHYS_NONSECURE_PPI])
+ disable_percpu_irq(arch_timer_ppi[PHYS_NONSECURE_PPI]);
+ }
+
+ clk->set_mode(CLOCK_EVT_MODE_UNUSED, clk);
}
static struct local_timer_ops arch_timer_ops __cpuinitdata = {
@@ -261,36 +385,48 @@ static struct clock_event_device arch_timer_global_evt;
static int __init arch_timer_register(void)
{
int err;
+ int ppi;
err = arch_timer_available();
if (err)
- return err;
+ goto out;
arch_timer_evt = alloc_percpu(struct clock_event_device *);
- if (!arch_timer_evt)
- return -ENOMEM;
+ if (!arch_timer_evt) {
+ err = -ENOMEM;
+ goto out;
+ }
clocksource_register_hz(&clocksource_counter, arch_timer_rate);
+ cyclecounter.mult = clocksource_counter.mult;
+ cyclecounter.shift = clocksource_counter.shift;
+ timecounter_init(&timecounter, &cyclecounter,
+ arch_counter_get_cntpct());
+
+ if (arch_timer_use_virtual) {
+ ppi = arch_timer_ppi[VIRT_PPI];
+ err = request_percpu_irq(ppi, arch_timer_handler_virt,
+ "arch_timer", arch_timer_evt);
+ } else {
+ ppi = arch_timer_ppi[PHYS_SECURE_PPI];
+ err = request_percpu_irq(ppi, arch_timer_handler_phys,
+ "arch_timer", arch_timer_evt);
+ if (!err && arch_timer_ppi[PHYS_NONSECURE_PPI]) {
+ ppi = arch_timer_ppi[PHYS_NONSECURE_PPI];
+ err = request_percpu_irq(ppi, arch_timer_handler_phys,
+ "arch_timer", arch_timer_evt);
+ if (err)
+ free_percpu_irq(arch_timer_ppi[PHYS_SECURE_PPI],
+ arch_timer_evt);
+ }
+ }
- 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);
+ 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) {
/*
@@ -302,21 +438,29 @@ static int __init arch_timer_register(void)
arch_timer_global_evt.cpumask = cpumask_of(0);
err = arch_timer_setup(&arch_timer_global_evt);
}
-
if (err)
goto out_free_irq;
- init_current_timer_delay(arch_timer_rate);
+ /* Use the architected timer for the delay loop. */
+ arch_delay_timer.read_current_timer = &arch_timer_read_current_timer;
+ arch_delay_timer.freq = arch_timer_rate;
+ register_current_timer_delay(&arch_delay_timer);
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);
+ if (arch_timer_use_virtual)
+ free_percpu_irq(arch_timer_ppi[VIRT_PPI], arch_timer_evt);
+ else {
+ free_percpu_irq(arch_timer_ppi[PHYS_SECURE_PPI],
+ arch_timer_evt);
+ if (arch_timer_ppi[PHYS_NONSECURE_PPI])
+ free_percpu_irq(arch_timer_ppi[PHYS_NONSECURE_PPI],
+ arch_timer_evt);
+ }
out_free:
free_percpu(arch_timer_evt);
-
+out:
return err;
}
@@ -329,6 +473,7 @@ int __init arch_timer_of_register(void)
{
struct device_node *np;
u32 freq;
+ int i;
np = of_find_matching_node(NULL, arch_timer_of_match);
if (!np) {
@@ -340,22 +485,40 @@ int __init arch_timer_of_register(void)
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);
+ for (i = PHYS_SECURE_PPI; i < MAX_TIMER_PPI; i++)
+ arch_timer_ppi[i] = irq_of_parse_and_map(np, i);
+
+ /*
+ * If no interrupt provided for virtual timer, we'll have to
+ * stick to the physical timer. It'd better be accessible...
+ */
+ if (!arch_timer_ppi[VIRT_PPI]) {
+ arch_timer_use_virtual = false;
+
+ if (!arch_timer_ppi[PHYS_SECURE_PPI] ||
+ !arch_timer_ppi[PHYS_NONSECURE_PPI]) {
+ pr_warn("arch_timer: No interrupt available, giving up\n");
+ return -EINVAL;
+ }
+ }
return arch_timer_register();
}
int __init arch_timer_sched_clock_init(void)
{
+ u32 (*cnt32)(void);
int err;
err = arch_timer_available();
if (err)
return err;
- setup_sched_clock(arch_counter_get_cntvct32, 32, arch_timer_rate);
+ if (arch_timer_use_virtual)
+ cnt32 = arch_counter_get_cntvct32;
+ else
+ cnt32 = arch_counter_get_cntpct32;
+
+ setup_sched_clock(cnt32, 32, arch_timer_rate);
return 0;
}
diff --git a/arch/arm/lib/delay.c b/arch/arm/lib/delay.c
index 395d5fb..9d0a300 100644
--- a/arch/arm/lib/delay.c
+++ b/arch/arm/lib/delay.c
@@ -34,7 +34,18 @@ struct arm_delay_ops arm_delay_ops = {
.udelay = __loop_udelay,
};
-#ifdef ARCH_HAS_READ_CURRENT_TIMER
+static const struct delay_timer *delay_timer;
+static bool delay_calibrated;
+
+int read_current_timer(unsigned long *timer_val)
+{
+ if (!delay_timer)
+ return -ENXIO;
+
+ *timer_val = delay_timer->read_current_timer();
+ return 0;
+}
+
static void __timer_delay(unsigned long cycles)
{
cycles_t start = get_cycles();
@@ -55,18 +66,24 @@ static void __timer_udelay(unsigned long usecs)
__timer_const_udelay(usecs * UDELAY_MULT);
}
-void __init init_current_timer_delay(unsigned long freq)
+void __init register_current_timer_delay(const struct delay_timer *timer)
{
- pr_info("Switching to timer-based delay loop\n");
- lpj_fine = freq / HZ;
- loops_per_jiffy = lpj_fine;
- arm_delay_ops.delay = __timer_delay;
- arm_delay_ops.const_udelay = __timer_const_udelay;
- arm_delay_ops.udelay = __timer_udelay;
+ if (!delay_calibrated) {
+ pr_info("Switching to timer-based delay loop\n");
+ delay_timer = timer;
+ lpj_fine = timer->freq / HZ;
+ loops_per_jiffy = lpj_fine;
+ arm_delay_ops.delay = __timer_delay;
+ arm_delay_ops.const_udelay = __timer_const_udelay;
+ arm_delay_ops.udelay = __timer_udelay;
+ delay_calibrated = true;
+ } else {
+ pr_info("Ignoring duplicate/late registration of read_current_timer delay\n");
+ }
}
unsigned long __cpuinit calibrate_delay_is_known(void)
{
+ delay_calibrated = true;
return lpj_fine;
}
-#endif
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