Commit 55dd23ec authored by Daniel Hellstrom's avatar Daniel Hellstrom Committed by David S. Miller
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sparc32, sun4d: Implemented SMP IPIs support for SUN4D machines 



The sun4d does not seem to have a distingstion between soft and hard
IRQs. When generating IPIs the generated IRQ looks like a hard IRQ,
this patch adds a "IPI check" in the sun4d irq trap handler at a
predefined IRQ number (SUN4D_IPI_IRQ). Before generating an IPI
a per-cpu memory structure is modified for the "IPI check" to
successfully detect a IPI request to a specific processor, the check
clears the IPI work requested.

All three IPIs (resched, single and cpu-mask) use the same IRQ
number.

The IPI IRQ should preferrably be on a separate IRQ and definitly
not shared with IRQ handlers requesting IRQ with IRQF_SHARED.

Signed-off-by: default avatarDaniel Hellstrom <daniel@gaisler.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent ecbc42b7

arch/sparc/kernel/irq.h

+6 −0
Original line number Diff line number Diff line
@@ -86,4 +86,10 @@ BTFIXUPDEF_CALL(void, set_irq_udt, int) 
#define set_cpu_int(cpu,level) BTFIXUP_CALL(set_cpu_int)(cpu,level)

#define clear_cpu_int(cpu,level) BTFIXUP_CALL(clear_cpu_int)(cpu,level)

#define set_irq_udt(cpu) BTFIXUP_CALL(set_irq_udt)(cpu)



/* All SUN4D IPIs are sent on this IRQ, may be shared with hard IRQs */

#define SUN4D_IPI_IRQ 14



extern void sun4d_ipi_interrupt(void);



#endif

arch/sparc/kernel/sun4d_irq.c

+9 −0
Original line number Diff line number Diff line
@@ -156,6 +156,15 @@ void sun4d_handler_irq(int pil, struct pt_regs *regs) 


	cc_set_iclr(1 << pil);



#ifdef CONFIG_SMP

	/*

	 * Check IPI data structures after IRQ has been cleared. Hard and Soft

	 * IRQ can happen at the same time, so both cases are always handled.

	 */

	if (pil == SUN4D_IPI_IRQ)

		sun4d_ipi_interrupt();

#endif



	old_regs = set_irq_regs(regs);

	irq_enter();

	if (sbusl == 0) {

arch/sparc/kernel/sun4d_smp.c

+79 −0
Original line number Diff line number Diff line
@@ -32,6 +32,7 @@ static inline unsigned long sun4d_swap(volatile unsigned long *ptr, unsigned lon 
	return val;

}



static void smp4d_ipi_init(void);

static void smp_setup_percpu_timer(void);



static unsigned char cpu_leds[32];
@@ -118,6 +119,7 @@ void __cpuinit smp4d_callin(void) 
 */

void __init smp4d_boot_cpus(void)

{

	smp4d_ipi_init();

	if (boot_cpu_id)

		current_set[0] = NULL;

	smp_setup_percpu_timer();
@@ -189,6 +191,80 @@ void __init smp4d_smp_done(void) 
	sun4d_distribute_irqs();

}



/* Memory structure giving interrupt handler information about IPI generated */

struct sun4d_ipi_work {

	int single;

	int msk;

	int resched;

};



static DEFINE_PER_CPU_SHARED_ALIGNED(struct sun4d_ipi_work, sun4d_ipi_work);



/* Initialize IPIs on the SUN4D SMP machine */

static void __init smp4d_ipi_init(void)

{

	int cpu;

	struct sun4d_ipi_work *work;



	printk(KERN_INFO "smp4d: setup IPI at IRQ %d\n", SUN4D_IPI_IRQ);



	for_each_possible_cpu(cpu) {

		work = &per_cpu(sun4d_ipi_work, cpu);

		work->single = work->msk = work->resched = 0;

	}

}



void sun4d_ipi_interrupt(void)

{

	struct sun4d_ipi_work *work = &__get_cpu_var(sun4d_ipi_work);



	if (work->single) {

		work->single = 0;

		smp_call_function_single_interrupt();

	}

	if (work->msk) {

		work->msk = 0;

		smp_call_function_interrupt();

	}

	if (work->resched) {

		work->resched = 0;

		smp_resched_interrupt();

	}

}



static void smp4d_ipi_single(int cpu)

{

	struct sun4d_ipi_work *work = &per_cpu(sun4d_ipi_work, cpu);



	/* Mark work */

	work->single = 1;



	/* Generate IRQ on the CPU */

	sun4d_send_ipi(cpu, SUN4D_IPI_IRQ);

}



static void smp4d_ipi_mask_one(int cpu)

{

	struct sun4d_ipi_work *work = &per_cpu(sun4d_ipi_work, cpu);



	/* Mark work */

	work->msk = 1;



	/* Generate IRQ on the CPU */

	sun4d_send_ipi(cpu, SUN4D_IPI_IRQ);

}



static void smp4d_ipi_resched(int cpu)

{

	struct sun4d_ipi_work *work = &per_cpu(sun4d_ipi_work, cpu);



	/* Mark work */

	work->resched = 1;



	/* Generate IRQ on the CPU (any IRQ will cause resched) */

	sun4d_send_ipi(cpu, SUN4D_IPI_IRQ);

}



static struct smp_funcall {

	smpfunc_t func;

	unsigned long arg1;
@@ -354,6 +430,9 @@ void __init sun4d_init_smp(void) 
	BTFIXUPSET_BLACKBOX(load_current, smp4d_blackbox_current);

	BTFIXUPSET_CALL(smp_cross_call, smp4d_cross_call, BTFIXUPCALL_NORM);

	BTFIXUPSET_CALL(__hard_smp_processor_id, __smp4d_processor_id, BTFIXUPCALL_NORM);

	BTFIXUPSET_CALL(smp_ipi_resched, smp4d_ipi_resched, BTFIXUPCALL_NORM);

	BTFIXUPSET_CALL(smp_ipi_single, smp4d_ipi_single, BTFIXUPCALL_NORM);

	BTFIXUPSET_CALL(smp_ipi_mask_one, smp4d_ipi_mask_one, BTFIXUPCALL_NORM);



	for (i = 0; i < NR_CPUS; i++) {

		ccall_info.processors_in[i] = 1;

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