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Commit d0453365 authored by Ralf Baechle's avatar Ralf Baechle
Browse files

[MIPS] time: SMP-proofing of Sibyte clockevent/clocksource code. 



The BCM148 has 4 cores but there are also just 4 generic timers available
so use the ZBbus cycle counter instead of it.  In addition the ZBbus
counter also offers a much higher resolution and 64-bit counting so I'm
considering a later complete conversion to it once I figure out if all
members of the Sibyte SOC family support it - the docs seem to agree but
the headers files seem to disagree ...

Signed-off-by: default avatarRalf Baechle <ralf@linux-mips.org>
parent 06d428d7

arch/mips/sibyte/bcm1480/irq.c

+41 −34
Original line number Diff line number Diff line
@@ -452,24 +452,8 @@ static void bcm1480_kgdb_interrupt(void) 


extern void bcm1480_mailbox_interrupt(void);



asmlinkage void plat_irq_dispatch(void)

static inline void dispatch_ip4(void)

{

	unsigned int pending;



#ifdef CONFIG_SIBYTE_BCM1480_PROF

	/* Set compare to count to silence count/compare timer interrupts */

	write_c0_compare(read_c0_count());

#endif



	pending = read_c0_cause() & read_c0_status();



#ifdef CONFIG_SIBYTE_BCM1480_PROF

	if (pending & CAUSEF_IP7)	/* Cpu performance counter interrupt */

		sbprof_cpu_intr();

	else

#endif



	if (pending & CAUSEF_IP4) {

	int cpu = smp_processor_id();

	int irq = K_BCM1480_INT_TIMER_0 + cpu;
@@ -480,27 +464,18 @@ asmlinkage void plat_irq_dispatch(void) 
	do_IRQ(irq);

}



#ifdef CONFIG_SMP

	else if (pending & CAUSEF_IP3)

		bcm1480_mailbox_interrupt();

#endif



#ifdef CONFIG_KGDB

	else if (pending & CAUSEF_IP6)

		bcm1480_kgdb_interrupt();		/* KGDB (uart 1) */

#endif



	else if (pending & CAUSEF_IP2) {

static inline void dispatch_ip2(void)

{

	unsigned long long mask_h, mask_l;

	unsigned int cpu = smp_processor_id();

	unsigned long base;



	/*

		 * Default...we've hit an IP[2] interrupt, which means we've

		 * got to check the 1480 interrupt registers to figure out what

		 * to do.  Need to detect which CPU we're on, now that

		 * smp_affinity is supported.

	 * Default...we've hit an IP[2] interrupt, which means we've got to

	 * check the 1480 interrupt registers to figure out what to do.  Need

	 * to detect which CPU we're on, now that smp_affinity is supported.

	 */

		base = A_BCM1480_IMR_MAPPER(smp_processor_id());

	base = A_BCM1480_IMR_MAPPER(cpu);

	mask_h = __raw_readq(

		IOADDR(base + R_BCM1480_IMR_INTERRUPT_STATUS_BASE_H));

	mask_l = __raw_readq(
@@ -509,8 +484,40 @@ asmlinkage void plat_irq_dispatch(void) 
	if (mask_h) {

		if (mask_h ^ 1)

			do_IRQ(fls64(mask_h) - 1);

			else

		else if (mask_l)

			do_IRQ(63 + fls64(mask_l));

	}

}



asmlinkage void plat_irq_dispatch(void)

{

	unsigned int pending;



#ifdef CONFIG_SIBYTE_BCM1480_PROF

	/* Set compare to count to silence count/compare timer interrupts */

	write_c0_compare(read_c0_count());

#endif



	pending = read_c0_cause() & read_c0_status();



#ifdef CONFIG_SIBYTE_BCM1480_PROF

	if (pending & CAUSEF_IP7)	/* Cpu performance counter interrupt */

		sbprof_cpu_intr();

	else

#endif



	if (pending & CAUSEF_IP4)

		dispatch_ip4();

#ifdef CONFIG_SMP

	else if (pending & CAUSEF_IP3)

		bcm1480_mailbox_interrupt();

#endif



#ifdef CONFIG_KGDB

	else if (pending & CAUSEF_IP6)

		bcm1480_kgdb_interrupt();		/* KGDB (uart 1) */

#endif



	else if (pending & CAUSEF_IP2)

		dispatch_ip2();

}

arch/mips/sibyte/bcm1480/smp.c

+2 −2
Original line number Diff line number Diff line
@@ -58,7 +58,7 @@ static void *mailbox_0_regs[] = { 
/*

 * SMP init and finish on secondary CPUs

 */

void bcm1480_smp_init(void)

void __cpuinit bcm1480_smp_init(void)

{

	unsigned int imask = STATUSF_IP4 | STATUSF_IP3 | STATUSF_IP2 |

		STATUSF_IP1 | STATUSF_IP0;
@@ -67,7 +67,7 @@ void bcm1480_smp_init(void) 
	change_c0_status(ST0_IM, imask);

}



void bcm1480_smp_finish(void)

void __cpuinit bcm1480_smp_finish(void)

{

	extern void sb1480_clockevent_init(void);

arch/mips/sibyte/bcm1480/time.c

+50 −67
Original line number Diff line number Diff line
@@ -15,22 +15,12 @@ 
 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.

 */



/*

 * These are routines to set up and handle interrupts from the

 * bcm1480 general purpose timer 0.  We're using the timer as a

 * system clock, so we set it up to run at 100 Hz.  On every

 * interrupt, we update our idea of what the time of day is,

 * then call do_timer() in the architecture-independent kernel

 * code to do general bookkeeping (e.g. update jiffies, run

 * bottom halves, etc.)

 */

#include <linux/clockchips.h>

#include <linux/interrupt.h>

#include <linux/irq.h>

#include <linux/percpu.h>

#include <linux/spinlock.h>



#include <asm/irq.h>

#include <asm/addrspace.h>

#include <asm/time.h>

#include <asm/io.h>
@@ -47,33 +37,10 @@ 
#define IMR_IP3_VAL	K_BCM1480_INT_MAP_I1

#define IMR_IP4_VAL	K_BCM1480_INT_MAP_I2



#ifdef CONFIG_SIMULATION

#define BCM1480_HPT_VALUE	50000

#else

#define BCM1480_HPT_VALUE	1000000

#endif



extern int bcm1480_steal_irq(int irq);



void __init plat_time_init(void)

{

	unsigned int cpu = smp_processor_id();

	unsigned int irq = K_BCM1480_INT_TIMER_0 + cpu;



	BUG_ON(cpu > 3);	/* Only have 4 general purpose timers */



	bcm1480_mask_irq(cpu, irq);



	/* Map the timer interrupt to ip[4] of this cpu */

	__raw_writeq(IMR_IP4_VAL, IOADDR(A_BCM1480_IMR_REGISTER(cpu, R_BCM1480_IMR_INTERRUPT_MAP_BASE_H)

	      + (irq<<3)));



	bcm1480_unmask_irq(cpu, irq);

	bcm1480_steal_irq(irq);

}



/*

 * The general purpose timer ticks at 1 Mhz independent if

 * The general purpose timer ticks at 1MHz independent if

 * the rest of the system

 */

static void sibyte_set_mode(enum clock_event_mode mode,
@@ -88,7 +55,7 @@ static void sibyte_set_mode(enum clock_event_mode mode, 
	switch (mode) {

	case CLOCK_EVT_MODE_PERIODIC:

		__raw_writeq(0, timer_cfg);

		__raw_writeq(BCM1480_HPT_VALUE / HZ - 1, timer_init);

		__raw_writeq((V_SCD_TIMER_FREQ / HZ) - 1, timer_init);

		__raw_writeq(M_SCD_TIMER_ENABLE | M_SCD_TIMER_MODE_CONTINUOUS,

			     timer_cfg);

		break;
@@ -121,80 +88,96 @@ static int sibyte_next_event(unsigned long delta, struct clock_event_device *cd) 
	return res;

}



static DEFINE_PER_CPU(struct clock_event_device, sibyte_hpt_clockevent);



static irqreturn_t sibyte_counter_handler(int irq, void *dev_id)

{

	unsigned int cpu = smp_processor_id();

	struct clock_event_device *cd = &per_cpu(sibyte_hpt_clockevent, cpu);

	struct clock_event_device *cd = dev_id;

	void __iomem *timer_cfg;



	timer_cfg = IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_CFG));



	/* Reset the timer */

	__raw_writeq(M_SCD_TIMER_ENABLE | M_SCD_TIMER_MODE_CONTINUOUS,

	             IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_CFG)));

	             timer_cfg);

	cd->event_handler(cd);



	return IRQ_HANDLED;

}



static struct irqaction sibyte_counter_irqaction = {

	.handler	= sibyte_counter_handler,

	.flags		= IRQF_DISABLED | IRQF_PERCPU,

	.name		= "timer",

};

static DEFINE_PER_CPU(struct clock_event_device, sibyte_hpt_clockevent);

static DEFINE_PER_CPU(struct irqaction, sibyte_hpt_irqaction);

static DEFINE_PER_CPU(char [18], sibyte_hpt_name);



/*

 * This interrupt is "special" in that it doesn't use the request_irq

 * way to hook the irq line.  The timer interrupt is initialized early

 * enough to make this a major pain, and it's also firing enough to

 * warrant a bit of special case code.  bcm1480_timer_interrupt is

 * called directly from irq_handler.S when IP[4] is set during an

 * interrupt

 */

void __cpuinit sb1480_clockevent_init(void)

{

	unsigned int cpu = smp_processor_id();

	unsigned int irq = K_BCM1480_INT_TIMER_0 + cpu;

	struct irqaction *action = &per_cpu(sibyte_hpt_irqaction, cpu);

	struct clock_event_device *cd = &per_cpu(sibyte_hpt_clockevent, cpu);

	unsigned char *name = per_cpu(sibyte_hpt_name, cpu);



	cd->name		= "bcm1480-counter";

	BUG_ON(cpu > 3);	/* Only have 4 general purpose timers */



	sprintf(name, "bcm1480-counter %d", cpu);

	cd->name		= name;

	cd->features		= CLOCK_EVT_FEAT_PERIODIC |

				  CLOCK_EVT_MODE_ONESHOT;

	clockevent_set_clock(cd, V_SCD_TIMER_FREQ);

	cd->max_delta_ns	= clockevent_delta2ns(0x7fffff, cd);

	cd->min_delta_ns	= clockevent_delta2ns(1, cd);

	cd->rating		= 200;

	cd->irq			= irq;

	cd->cpumask		= cpumask_of_cpu(cpu);

	cd->set_next_event	= sibyte_next_event;

	cd->set_mode		= sibyte_set_mode;

	cd->irq			= irq;

	clockevent_set_clock(cd, BCM1480_HPT_VALUE);

	clockevents_register_device(cd);



	bcm1480_mask_irq(cpu, irq);



	/*

	 * Map timer interrupt to IP[4] of this cpu

	 */

	__raw_writeq(IMR_IP4_VAL,

		     IOADDR(A_BCM1480_IMR_REGISTER(cpu,

			R_BCM1480_IMR_INTERRUPT_MAP_BASE_H) + (irq << 3)));



	setup_irq(irq, &sibyte_counter_irqaction);

	bcm1480_unmask_irq(cpu, irq);

	bcm1480_steal_irq(irq);



	action->handler	= sibyte_counter_handler;

	action->flags	= IRQF_DISABLED | IRQF_PERCPU;

	action->name	= name;

	action->dev_id	= cd;

	setup_irq(irq, action);

}



static cycle_t bcm1480_hpt_read(void)

{

	/* We assume this function is called xtime_lock held. */

	unsigned long count =

		__raw_readq(IOADDR(A_SCD_TIMER_REGISTER(0, R_SCD_TIMER_CNT)));

	return (jiffies + 1) * (BCM1480_HPT_VALUE / HZ) - count;

	return (cycle_t) __raw_readq(IOADDR(A_SCD_ZBBUS_CYCLE_COUNT));

}



struct clocksource bcm1480_clocksource = {

	.name	= "MIPS",

	.name	= "zbbus-cycles",

	.rating	= 200,

	.read	= bcm1480_hpt_read,

	.mask	= CLOCKSOURCE_MASK(32),

	.shift	= 32,

	.mask	= CLOCKSOURCE_MASK(64),

	.flags	= CLOCK_SOURCE_IS_CONTINUOUS,

};



void __init sb1480_clocksource_init(void)

{

	struct clocksource *cs = &bcm1480_clocksource;

	unsigned int plldiv;

	unsigned long zbbus;



	clocksource_set_clock(cs, BCM1480_HPT_VALUE);

	plldiv = G_BCM1480_SYS_PLL_DIV(__raw_readq(IOADDR(A_SCD_SYSTEM_CFG)));

	zbbus = ((plldiv >> 1) * 50000000) + ((plldiv & 1) * 25000000);

	clocksource_set_clock(cs, zbbus);

	clocksource_register(cs);

}



void __init bcm1480_hpt_setup(void)

void __init plat_time_init(void)

{

	mips_hpt_frequency = BCM1480_HPT_VALUE;

	sb1480_clocksource_init();

	sb1480_clockevent_init();

}

arch/mips/sibyte/sb1250/irq.c

+19 −16
Original line number Diff line number Diff line
@@ -402,6 +402,22 @@ static void sb1250_kgdb_interrupt(void) 


extern void sb1250_mailbox_interrupt(void);



static inline void dispatch_ip2(void)

{

	unsigned int cpu = smp_processor_id();

	unsigned long long mask;



	/*

	 * Default...we've hit an IP[2] interrupt, which means we've got to

	 * check the 1250 interrupt registers to figure out what to do.  Need

	 * to detect which CPU we're on, now that smp_affinity is supported.

	 */

	mask = __raw_readq(IOADDR(A_IMR_REGISTER(cpu,

				  R_IMR_INTERRUPT_STATUS_BASE)));

	if (mask)

		do_IRQ(fls64(mask) - 1);

}



asmlinkage void plat_irq_dispatch(void)

{

	unsigned int cpu = smp_processor_id();
@@ -434,21 +450,8 @@ asmlinkage void plat_irq_dispatch(void) 
		sb1250_kgdb_interrupt();

#endif



	else if (pending & CAUSEF_IP2) {

		unsigned long long mask;



		/*

		 * Default...we've hit an IP[2] interrupt, which means we've

		 * got to check the 1250 interrupt registers to figure out what

		 * to do.  Need to detect which CPU we're on, now that

		 * smp_affinity is supported.

		 */

		mask = __raw_readq(IOADDR(A_IMR_REGISTER(smp_processor_id(),

		                              R_IMR_INTERRUPT_STATUS_BASE)));

		if (mask)

			do_IRQ(fls64(mask) - 1);

	else if (pending & CAUSEF_IP2)

		dispatch_ip2();

	else

		spurious_interrupt();

	} else

		spurious_interrupt();

}

arch/mips/sibyte/sb1250/smp.c

+2 −2
Original line number Diff line number Diff line
@@ -46,7 +46,7 @@ static void *mailbox_regs[] = { 
/*

 * SMP init and finish on secondary CPUs

 */

void sb1250_smp_init(void)

void __cpuinit sb1250_smp_init(void)

{

	unsigned int imask = STATUSF_IP4 | STATUSF_IP3 | STATUSF_IP2 |

		STATUSF_IP1 | STATUSF_IP0;
@@ -55,7 +55,7 @@ void sb1250_smp_init(void) 
	change_c0_status(ST0_IM, imask);

}



void sb1250_smp_finish(void)

void __cpuinit sb1250_smp_finish(void)

{

	extern void sb1250_clockevent_init(void);