From a91549a8f27e63e0e537fe1c20d4845581de894f Mon Sep 17 00:00:00 2001 From: Mikael Pettersson Date: Thu, 29 Oct 2009 11:46:54 -0700 Subject: iop: clocksource support This updates the IOP platform to expose the free-running timer 1 as a clocksource object. This timer is now also properly initialised, which requires a new write_tcr1() function from the mach-specific code. Apart from the explicit initialisation, there is no functional change in how timer 1 is programmed. Tested on n2100, compile-tested for all plat-iop machines. Signed-off-by: Mikael Pettersson Signed-off-by: Dan Williams --- arch/arm/include/asm/hardware/iop3xx.h | 5 ++++ arch/arm/mach-iop13xx/include/mach/time.h | 5 ++++ arch/arm/plat-iop/time.c | 45 +++++++++++++++++++++++++++++++ 3 files changed, 55 insertions(+) diff --git a/arch/arm/include/asm/hardware/iop3xx.h b/arch/arm/include/asm/hardware/iop3xx.h index 8d60ad267e3..643b7b95b25 100644 --- a/arch/arm/include/asm/hardware/iop3xx.h +++ b/arch/arm/include/asm/hardware/iop3xx.h @@ -260,6 +260,11 @@ 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 d6d52527589..9fb2768c84b 100644 --- a/arch/arm/mach-iop13xx/include/mach/time.h +++ b/arch/arm/mach-iop13xx/include/mach/time.h @@ -90,6 +90,11 @@ 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/plat-iop/time.c b/arch/arm/plat-iop/time.c index 8da95d57c21..5506c9b4561 100644 --- a/arch/arm/plat-iop/time.c +++ b/arch/arm/plat-iop/time.c @@ -19,6 +19,7 @@ #include #include #include +#include #include #include #include @@ -26,6 +27,43 @@ #include #include +/* + * 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); +} + static unsigned long ticks_per_jiffy; static unsigned long ticks_per_usec; static unsigned long next_jiffy_time; @@ -99,8 +137,15 @@ void __init iop_init_time(unsigned long tick_rate) */ write_trr0(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); + iop_clocksource_set_hz(&iop_clocksource, tick_rate); + clocksource_register(&iop_clocksource); setup_irq(IRQ_IOP_TIMER0, &iop_timer_irq); } -- cgit v1.2.3 From 469d30448dad13600cdd246024f9db8e80614c45 Mon Sep 17 00:00:00 2001 From: Mikael Pettersson Date: Thu, 29 Oct 2009 11:46:54 -0700 Subject: iop: clockevent support This updates the IOP platform to expose the interrupting timer 0 as a clockevent object. The timer interrupt handler is changed to call the clockevent ->event_handler() instead of timer_tick(), and ->set_next_event() and ->set_mode() operations are added to allow the mode of the timer to be updated (required for ONESHOT/NOHZ mode). Timer 0 must now be properly initialised, which requires a new write_tcr0() function from the mach-specific code. The mode of timer 0 must be read at the start of ->set_mode(), which requires a new read_tmr0() function from the mach- specific code. Initial setup of timer 0 is also rewritten to be more robust. Tested on n2100, compile-tested for all plat-iop machines. Signed-off-by: Mikael Pettersson Signed-off-by: Dan Williams --- arch/arm/Kconfig | 1 + arch/arm/include/asm/hardware/iop3xx.h | 12 ++++ arch/arm/mach-iop13xx/include/mach/time.h | 12 ++++ arch/arm/plat-iop/time.c | 101 ++++++++++++++++++++++++++---- 4 files changed, 115 insertions(+), 11 deletions(-) diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 1c4119c6004..e732fcc3052 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -810,6 +810,7 @@ config ARCH_ACORN config PLAT_IOP bool + select GENERIC_CLOCKEVENTS config PLAT_ORION bool diff --git a/arch/arm/include/asm/hardware/iop3xx.h b/arch/arm/include/asm/hardware/iop3xx.h index 643b7b95b25..34601b95204 100644 --- a/arch/arm/include/asm/hardware/iop3xx.h +++ b/arch/arm/include/asm/hardware/iop3xx.h @@ -236,6 +236,13 @@ 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) { asm volatile("mcr p6, 0, %0, c0, c1, 0" : : "r" (val)); @@ -253,6 +260,11 @@ 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; diff --git a/arch/arm/mach-iop13xx/include/mach/time.h b/arch/arm/mach-iop13xx/include/mach/time.h index 9fb2768c84b..b2fb17b3542 100644 --- a/arch/arm/mach-iop13xx/include/mach/time.h +++ b/arch/arm/mach-iop13xx/include/mach/time.h @@ -66,6 +66,13 @@ 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 +90,11 @@ 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; diff --git a/arch/arm/plat-iop/time.c b/arch/arm/plat-iop/time.c index 5506c9b4561..a550e96394a 100644 --- a/arch/arm/plat-iop/time.c +++ b/arch/arm/plat-iop/time.c @@ -20,6 +20,7 @@ #include #include #include +#include #include #include #include @@ -64,7 +65,81 @@ static void __init iop_clocksource_set_hz(struct clocksource *cs, unsigned int h cs->name, cs->shift, cs->mult); } +/* + * 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 void iop_set_mode(enum clock_event_mode mode, + struct clock_event_device *unused) +{ + 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; + } + + 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 unsigned long ticks_per_usec; static unsigned long next_jiffy_time; @@ -95,14 +170,10 @@ unsigned long iop_gettimeoffset(void) 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; } @@ -110,6 +181,7 @@ 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; @@ -132,10 +204,19 @@ void __init iop_init_time(unsigned long tick_rate) 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); /* @@ -146,6 +227,4 @@ void __init iop_init_time(unsigned long tick_rate) write_tmr1(timer_ctl); iop_clocksource_set_hz(&iop_clocksource, tick_rate); clocksource_register(&iop_clocksource); - - setup_irq(IRQ_IOP_TIMER0, &iop_timer_irq); } -- cgit v1.2.3 From 980f2296b5a8dfe589f023fd34229dcfdcf280fa Mon Sep 17 00:00:00 2001 From: Mikael Pettersson Date: Thu, 29 Oct 2009 11:46:55 -0700 Subject: iop: enable generic time This updates the IOP platform to use the kernel's generic time framework. With clockevent support in place, this reduces to selecting GENERIC_TIME and removing the platform's private timer ->offset() operation (iop_gettimeoffset). Tested on n2100, compile-tested for all plat-iop machines. Signed-off-by: Mikael Pettersson Signed-off-by: Dan Williams --- arch/arm/Kconfig | 1 + arch/arm/include/asm/hardware/iop3xx.h | 1 - arch/arm/mach-iop13xx/include/mach/time.h | 1 - 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/plat-iop/time.c | 29 ----------------------------- 13 files changed, 1 insertion(+), 40 deletions(-) diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index e732fcc3052..455284edda2 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -811,6 +811,7 @@ 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 34601b95204..5daea2961d4 100644 --- a/arch/arm/include/asm/hardware/iop3xx.h +++ b/arch/arm/include/asm/hardware/iop3xx.h @@ -234,7 +234,6 @@ 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) { diff --git a/arch/arm/mach-iop13xx/include/mach/time.h b/arch/arm/mach-iop13xx/include/mach/time.h index b2fb17b3542..f1c00d6d560 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) { diff --git a/arch/arm/mach-iop13xx/iq81340mc.c b/arch/arm/mach-iop13xx/iq81340mc.c index 5051c03d437..f91f3154577 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 bc443073a8e..ddb7a3435de 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 3ad4696ade4..2bef9b6e1cc 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 a9c2dfdb250..93370a46b62 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 dd1cd990451..a7a08dda7f3 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 fbe27798759..0200f80c1e1 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 d2e42789972..2a5c637639b 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 d51e10cddf2..394e95a30b7 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 92fb44cdbca..a40badf126c 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/plat-iop/time.c b/arch/arm/plat-iop/time.c index a550e96394a..aaaef3b4bc6 100644 --- a/arch/arm/plat-iop/time.c +++ b/arch/arm/plat-iop/time.c @@ -140,33 +140,6 @@ static void __init iop_clockevent_set_hz(struct clock_event_device *ce, unsigned ce->name, ce->shift, ce->mult); } -static unsigned long ticks_per_usec; -static unsigned long next_jiffy_time; - -unsigned long iop_gettimeoffset(void) -{ - unsigned long offset, temp; - - /* 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; -} - static irqreturn_t iop_timer_interrupt(int irq, void *dev_id) { @@ -196,8 +169,6 @@ 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 | -- cgit v1.2.3 From 345a32296b1f9f6121379e0240915e0e2be2dbf5 Mon Sep 17 00:00:00 2001 From: Mikael Pettersson Date: Thu, 29 Oct 2009 11:46:56 -0700 Subject: iop: implement sched_clock() This adds a better sched_clock() to the IOP platform, implemented using its new clocksource support. Tested on n2100, compile-tested for all plat-iop machines. [dan.j.williams@intel.com: allow early cp6 access] Signed-off-by: Mikael Pettersson Signed-off-by: Dan Williams --- arch/arm/mm/proc-xsc3.S | 2 +- arch/arm/plat-iop/time.c | 11 +++++++++++ 2 files changed, 12 insertions(+), 1 deletion(-) diff --git a/arch/arm/mm/proc-xsc3.S b/arch/arm/mm/proc-xsc3.S index 2028f370288..fab134e2982 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 aaaef3b4bc6..6c8a02ad98e 100644 --- a/arch/arm/plat-iop/time.c +++ b/arch/arm/plat-iop/time.c @@ -65,6 +65,17 @@ static void __init iop_clocksource_set_hz(struct clocksource *cs, unsigned int h 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). */ -- cgit v1.2.3