[GIT PULL] iop clocksource support for 2.6.33
Dan Williams
dan.j.williams at intel.com
Fri Nov 20 17:00:48 EST 2009
Hi Russell, please pull from:
git://git.kernel.org/pub/scm/linux/kernel/git/djbw/xscaleiop.git next
...to receive Mikael's conversion of the plat-iop time implementation to
clocksource. This caught a difference between proc-xscale.S and
proc-xsc3.S in that the latter is not enabling cp6 access by default.
Thanks,
Dan
Mikael Pettersson (4):
iop: clocksource support
iop: clockevent support
iop: enable generic time
iop: implement sched_clock()
arch/arm/Kconfig | 2 +
arch/arm/include/asm/hardware/iop3xx.h | 18 +++-
arch/arm/mach-iop13xx/include/mach/time.h | 18 +++-
arch/arm/mach-iop13xx/iq81340mc.c | 1 -
arch/arm/mach-iop13xx/iq81340sc.c | 1 -
arch/arm/mach-iop32x/em7210.c | 1 -
arch/arm/mach-iop32x/glantank.c | 1 -
arch/arm/mach-iop32x/iq31244.c | 1 -
arch/arm/mach-iop32x/iq80321.c | 1 -
arch/arm/mach-iop32x/n2100.c | 1 -
arch/arm/mach-iop33x/iq80331.c | 1 -
arch/arm/mach-iop33x/iq80332.c | 1 -
arch/arm/mm/proc-xsc3.S | 2 +-
arch/arm/plat-iop/time.c | 176 +++++++++++++++++++++++------
14 files changed, 178 insertions(+), 47 deletions(-)
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 1c4119c..455284e 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -810,6 +810,8 @@ config ARCH_ACORN
config PLAT_IOP
bool
+ select GENERIC_CLOCKEVENTS
+ select GENERIC_TIME
config PLAT_ORION
bool
diff --git a/arch/arm/include/asm/hardware/iop3xx.h b/arch/arm/include/asm/hardware/iop3xx.h
index 8d60ad2..5daea29 100644
--- a/arch/arm/include/asm/hardware/iop3xx.h
+++ b/arch/arm/include/asm/hardware/iop3xx.h
@@ -234,7 +234,13 @@ extern int iop3xx_get_init_atu(void);
void iop3xx_map_io(void);
void iop_init_cp6_handler(void);
void iop_init_time(unsigned long tickrate);
-unsigned long iop_gettimeoffset(void);
+
+static inline u32 read_tmr0(void)
+{
+ u32 val;
+ asm volatile("mrc p6, 0, %0, c0, c1, 0" : "=r" (val));
+ return val;
+}
static inline void write_tmr0(u32 val)
{
@@ -253,6 +259,11 @@ static inline u32 read_tcr0(void)
return val;
}
+static inline void write_tcr0(u32 val)
+{
+ asm volatile("mcr p6, 0, %0, c2, c1, 0" : : "r" (val));
+}
+
static inline u32 read_tcr1(void)
{
u32 val;
@@ -260,6 +271,11 @@ static inline u32 read_tcr1(void)
return val;
}
+static inline void write_tcr1(u32 val)
+{
+ asm volatile("mcr p6, 0, %0, c3, c1, 0" : : "r" (val));
+}
+
static inline void write_trr0(u32 val)
{
asm volatile("mcr p6, 0, %0, c4, c1, 0" : : "r" (val));
diff --git a/arch/arm/mach-iop13xx/include/mach/time.h b/arch/arm/mach-iop13xx/include/mach/time.h
index d6d5252..f1c00d6 100644
--- a/arch/arm/mach-iop13xx/include/mach/time.h
+++ b/arch/arm/mach-iop13xx/include/mach/time.h
@@ -20,7 +20,6 @@
#define IOP13XX_CORE_FREQ_1200 (5 << 16)
void iop_init_time(unsigned long tickrate);
-unsigned long iop_gettimeoffset(void);
static inline unsigned long iop13xx_core_freq(void)
{
@@ -66,6 +65,13 @@ static inline unsigned long iop13xx_xsi_bus_ratio(void)
return 2;
}
+static inline u32 read_tmr0(void)
+{
+ u32 val;
+ asm volatile("mrc p6, 0, %0, c0, c9, 0" : "=r" (val));
+ return val;
+}
+
static inline void write_tmr0(u32 val)
{
asm volatile("mcr p6, 0, %0, c0, c9, 0" : : "r" (val));
@@ -83,6 +89,11 @@ static inline u32 read_tcr0(void)
return val;
}
+static inline void write_tcr0(u32 val)
+{
+ asm volatile("mcr p6, 0, %0, c2, c9, 0" : : "r" (val));
+}
+
static inline u32 read_tcr1(void)
{
u32 val;
@@ -90,6 +101,11 @@ static inline u32 read_tcr1(void)
return val;
}
+static inline void write_tcr1(u32 val)
+{
+ asm volatile("mcr p6, 0, %0, c3, c9, 0" : : "r" (val));
+}
+
static inline void write_trr0(u32 val)
{
asm volatile("mcr p6, 0, %0, c4, c9, 0" : : "r" (val));
diff --git a/arch/arm/mach-iop13xx/iq81340mc.c b/arch/arm/mach-iop13xx/iq81340mc.c
index 5051c03..f91f315 100644
--- a/arch/arm/mach-iop13xx/iq81340mc.c
+++ b/arch/arm/mach-iop13xx/iq81340mc.c
@@ -87,7 +87,6 @@ static void __init iq81340mc_timer_init(void)
static struct sys_timer iq81340mc_timer = {
.init = iq81340mc_timer_init,
- .offset = iop_gettimeoffset,
};
MACHINE_START(IQ81340MC, "Intel IQ81340MC")
diff --git a/arch/arm/mach-iop13xx/iq81340sc.c b/arch/arm/mach-iop13xx/iq81340sc.c
index bc44307..ddb7a34 100644
--- a/arch/arm/mach-iop13xx/iq81340sc.c
+++ b/arch/arm/mach-iop13xx/iq81340sc.c
@@ -89,7 +89,6 @@ static void __init iq81340sc_timer_init(void)
static struct sys_timer iq81340sc_timer = {
.init = iq81340sc_timer_init,
- .offset = iop_gettimeoffset,
};
MACHINE_START(IQ81340SC, "Intel IQ81340SC")
diff --git a/arch/arm/mach-iop32x/em7210.c b/arch/arm/mach-iop32x/em7210.c
index 3ad4696..2bef9b6 100644
--- a/arch/arm/mach-iop32x/em7210.c
+++ b/arch/arm/mach-iop32x/em7210.c
@@ -42,7 +42,6 @@ static void __init em7210_timer_init(void)
static struct sys_timer em7210_timer = {
.init = em7210_timer_init,
- .offset = iop_gettimeoffset,
};
/*
diff --git a/arch/arm/mach-iop32x/glantank.c b/arch/arm/mach-iop32x/glantank.c
index a9c2dfd..93370a4 100644
--- a/arch/arm/mach-iop32x/glantank.c
+++ b/arch/arm/mach-iop32x/glantank.c
@@ -47,7 +47,6 @@ static void __init glantank_timer_init(void)
static struct sys_timer glantank_timer = {
.init = glantank_timer_init,
- .offset = iop_gettimeoffset,
};
diff --git a/arch/arm/mach-iop32x/iq31244.c b/arch/arm/mach-iop32x/iq31244.c
index dd1cd99..a7a08dd 100644
--- a/arch/arm/mach-iop32x/iq31244.c
+++ b/arch/arm/mach-iop32x/iq31244.c
@@ -78,7 +78,6 @@ static void __init iq31244_timer_init(void)
static struct sys_timer iq31244_timer = {
.init = iq31244_timer_init,
- .offset = iop_gettimeoffset,
};
diff --git a/arch/arm/mach-iop32x/iq80321.c b/arch/arm/mach-iop32x/iq80321.c
index fbe2779..0200f80 100644
--- a/arch/arm/mach-iop32x/iq80321.c
+++ b/arch/arm/mach-iop32x/iq80321.c
@@ -46,7 +46,6 @@ static void __init iq80321_timer_init(void)
static struct sys_timer iq80321_timer = {
.init = iq80321_timer_init,
- .offset = iop_gettimeoffset,
};
diff --git a/arch/arm/mach-iop32x/n2100.c b/arch/arm/mach-iop32x/n2100.c
index d2e4278..2a5c637 100644
--- a/arch/arm/mach-iop32x/n2100.c
+++ b/arch/arm/mach-iop32x/n2100.c
@@ -53,7 +53,6 @@ static void __init n2100_timer_init(void)
static struct sys_timer n2100_timer = {
.init = n2100_timer_init,
- .offset = iop_gettimeoffset,
};
diff --git a/arch/arm/mach-iop33x/iq80331.c b/arch/arm/mach-iop33x/iq80331.c
index d51e10c..394e95a 100644
--- a/arch/arm/mach-iop33x/iq80331.c
+++ b/arch/arm/mach-iop33x/iq80331.c
@@ -48,7 +48,6 @@ static void __init iq80331_timer_init(void)
static struct sys_timer iq80331_timer = {
.init = iq80331_timer_init,
- .offset = iop_gettimeoffset,
};
diff --git a/arch/arm/mach-iop33x/iq80332.c b/arch/arm/mach-iop33x/iq80332.c
index 92fb44c..a40badf 100644
--- a/arch/arm/mach-iop33x/iq80332.c
+++ b/arch/arm/mach-iop33x/iq80332.c
@@ -48,7 +48,6 @@ static void __init iq80332_timer_init(void)
static struct sys_timer iq80332_timer = {
.init = iq80332_timer_init,
- .offset = iop_gettimeoffset,
};
diff --git a/arch/arm/mm/proc-xsc3.S b/arch/arm/mm/proc-xsc3.S
index 2028f37..fab134e 100644
--- a/arch/arm/mm/proc-xsc3.S
+++ b/arch/arm/mm/proc-xsc3.S
@@ -396,7 +396,7 @@ __xsc3_setup:
orr r4, r4, #0x18 @ cache the page table in L2
mcr p15, 0, r4, c2, c0, 0 @ load page table pointer
- mov r0, #0 @ don't allow CP access
+ mov r0, #1 << 6 @ cp6 access for early sched_clock
mcr p15, 0, r0, c15, c1, 0 @ write CP access register
mrc p15, 0, r0, c1, c0, 1 @ get auxiliary control reg
diff --git a/arch/arm/plat-iop/time.c b/arch/arm/plat-iop/time.c
index 8da95d5..6c8a02a 100644
--- a/arch/arm/plat-iop/time.c
+++ b/arch/arm/plat-iop/time.c
@@ -19,6 +19,8 @@
#include <linux/init.h>
#include <linux/timex.h>
#include <linux/io.h>
+#include <linux/clocksource.h>
+#include <linux/clockchips.h>
#include <mach/hardware.h>
#include <asm/irq.h>
#include <asm/uaccess.h>
@@ -26,45 +28,136 @@
#include <asm/mach/time.h>
#include <mach/time.h>
+/*
+ * IOP clocksource (free-running timer 1).
+ */
+static cycle_t iop_clocksource_read(struct clocksource *unused)
+{
+ return 0xffffffffu - read_tcr1();
+}
+
+static struct clocksource iop_clocksource = {
+ .name = "iop_timer1",
+ .rating = 300,
+ .read = iop_clocksource_read,
+ .mask = CLOCKSOURCE_MASK(32),
+ .flags = CLOCK_SOURCE_IS_CONTINUOUS,
+};
+
+static void __init iop_clocksource_set_hz(struct clocksource *cs, unsigned int hz)
+{
+ u64 temp;
+ u32 shift;
+
+ /* Find shift and mult values for hz. */
+ shift = 32;
+ do {
+ temp = (u64) NSEC_PER_SEC << shift;
+ do_div(temp, hz);
+ if ((temp >> 32) == 0)
+ break;
+ } while (--shift != 0);
+
+ cs->shift = shift;
+ cs->mult = (u32) temp;
+
+ printk(KERN_INFO "clocksource: %s uses shift %u mult %#x\n",
+ cs->name, cs->shift, cs->mult);
+}
+
+/*
+ * IOP sched_clock() implementation via its clocksource.
+ */
+unsigned long long sched_clock(void)
+{
+ cycle_t cyc = iop_clocksource_read(NULL);
+ struct clocksource *cs = &iop_clocksource;
+
+ return clocksource_cyc2ns(cyc, cs->mult, cs->shift);
+}
+
+/*
+ * IOP clockevents (interrupting timer 0).
+ */
+static int iop_set_next_event(unsigned long delta,
+ struct clock_event_device *unused)
+{
+ u32 tmr = IOP_TMR_PRIVILEGED | IOP_TMR_RATIO_1_1;
+
+ BUG_ON(delta == 0);
+ write_tmr0(tmr & ~(IOP_TMR_EN | IOP_TMR_RELOAD));
+ write_tcr0(delta);
+ write_tmr0((tmr & ~IOP_TMR_RELOAD) | IOP_TMR_EN);
+
+ return 0;
+}
+
static unsigned long ticks_per_jiffy;
-static unsigned long ticks_per_usec;
-static unsigned long next_jiffy_time;
-unsigned long iop_gettimeoffset(void)
+static void iop_set_mode(enum clock_event_mode mode,
+ struct clock_event_device *unused)
{
- unsigned long offset, temp;
+ u32 tmr = read_tmr0();
+
+ switch (mode) {
+ case CLOCK_EVT_MODE_PERIODIC:
+ write_tmr0(tmr & ~IOP_TMR_EN);
+ write_tcr0(ticks_per_jiffy - 1);
+ tmr |= (IOP_TMR_RELOAD | IOP_TMR_EN);
+ break;
+ case CLOCK_EVT_MODE_ONESHOT:
+ /* ->set_next_event sets period and enables timer */
+ tmr &= ~(IOP_TMR_RELOAD | IOP_TMR_EN);
+ break;
+ case CLOCK_EVT_MODE_RESUME:
+ tmr |= IOP_TMR_EN;
+ break;
+ case CLOCK_EVT_MODE_SHUTDOWN:
+ case CLOCK_EVT_MODE_UNUSED:
+ default:
+ tmr &= ~IOP_TMR_EN;
+ break;
+ }
- /* enable cp6, if necessary, to avoid taking the overhead of an
- * undefined instruction trap
- */
- asm volatile (
- "mrc p15, 0, %0, c15, c1, 0\n\t"
- "tst %0, #(1 << 6)\n\t"
- "orreq %0, %0, #(1 << 6)\n\t"
- "mcreq p15, 0, %0, c15, c1, 0\n\t"
-#ifdef CONFIG_CPU_XSCALE
- "mrceq p15, 0, %0, c15, c1, 0\n\t"
- "moveq %0, %0\n\t"
- "subeq pc, pc, #4\n\t"
-#endif
- : "=r"(temp) : : "cc");
-
- offset = next_jiffy_time - read_tcr1();
-
- return offset / ticks_per_usec;
+ write_tmr0(tmr);
+}
+
+static struct clock_event_device iop_clockevent = {
+ .name = "iop_timer0",
+ .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
+ .rating = 300,
+ .set_next_event = iop_set_next_event,
+ .set_mode = iop_set_mode,
+};
+
+static void __init iop_clockevent_set_hz(struct clock_event_device *ce, unsigned int hz)
+{
+ u64 temp;
+ u32 shift;
+
+ /* Find shift and mult values for hz. */
+ shift = 32;
+ do {
+ temp = (u64) hz << shift;
+ do_div(temp, NSEC_PER_SEC);
+ if ((temp >> 32) == 0)
+ break;
+ } while (--shift != 0);
+
+ ce->shift = shift;
+ ce->mult = (u32) temp;
+
+ printk(KERN_INFO "clockevent: %s uses shift %u mult %#lx\n",
+ ce->name, ce->shift, ce->mult);
}
static irqreturn_t
iop_timer_interrupt(int irq, void *dev_id)
{
- write_tisr(1);
-
- while ((signed long)(next_jiffy_time - read_tcr1())
- >= ticks_per_jiffy) {
- timer_tick();
- next_jiffy_time -= ticks_per_jiffy;
- }
+ struct clock_event_device *evt = dev_id;
+ write_tisr(1);
+ evt->event_handler(evt);
return IRQ_HANDLED;
}
@@ -72,6 +165,7 @@ static struct irqaction iop_timer_irq = {
.name = "IOP Timer Tick",
.handler = iop_timer_interrupt,
.flags = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL,
+ .dev_id = &iop_clockevent,
};
static unsigned long iop_tick_rate;
@@ -86,21 +180,33 @@ void __init iop_init_time(unsigned long tick_rate)
u32 timer_ctl;
ticks_per_jiffy = DIV_ROUND_CLOSEST(tick_rate, HZ);
- ticks_per_usec = tick_rate / 1000000;
- next_jiffy_time = 0xffffffff;
iop_tick_rate = tick_rate;
timer_ctl = IOP_TMR_EN | IOP_TMR_PRIVILEGED |
IOP_TMR_RELOAD | IOP_TMR_RATIO_1_1;
/*
- * We use timer 0 for our timer interrupt, and timer 1 as
- * monotonic counter for tracking missed jiffies.
+ * Set up interrupting clockevent timer 0.
*/
+ write_tmr0(timer_ctl & ~IOP_TMR_EN);
+ setup_irq(IRQ_IOP_TIMER0, &iop_timer_irq);
+ iop_clockevent_set_hz(&iop_clockevent, tick_rate);
+ iop_clockevent.max_delta_ns =
+ clockevent_delta2ns(0xfffffffe, &iop_clockevent);
+ iop_clockevent.min_delta_ns =
+ clockevent_delta2ns(0xf, &iop_clockevent);
+ iop_clockevent.cpumask = cpumask_of(0);
+ clockevents_register_device(&iop_clockevent);
write_trr0(ticks_per_jiffy - 1);
+ write_tcr0(ticks_per_jiffy - 1);
write_tmr0(timer_ctl);
+
+ /*
+ * Set up free-running clocksource timer 1.
+ */
write_trr1(0xffffffff);
+ write_tcr1(0xffffffff);
write_tmr1(timer_ctl);
-
- setup_irq(IRQ_IOP_TIMER0, &iop_timer_irq);
+ iop_clocksource_set_hz(&iop_clocksource, tick_rate);
+ clocksource_register(&iop_clocksource);
}
More information about the linux-arm-kernel
mailing list