Commit ecc38a09 authored by Huacai Chen's avatar Huacai Chen Committed by Ralf Baechle
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MIPS: Loongson-3: support irq_set_affinity() in i8259 chip 



With this patch we can set irq affinity via procfs, so as to improve
network performance.

Signed-off-by: default avatarHuacai Chen <chenhc@lemote.com>
Cc: John Crispin <john@phrozen.org>
Cc: Steven J . Hill <Steven.Hill@cavium.com>
Cc: Fuxin Zhang <zhangfx@lemote.com>
Cc: Zhangjin Wu <wuzhangjin@gmail.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16590/


Signed-off-by: default avatarRalf Baechle <ralf@linux-mips.org>
parent e1b88ca8

arch/mips/loongson64/loongson-3/irq.c

+54 −13
Original line number Diff line number Diff line
@@ -10,32 +10,68 @@ 
#include "smp.h"



extern void loongson3_send_irq_by_ipi(int cpu, int irqs);



unsigned int irq_cpu[16] = {[0 ... 15] = -1};

unsigned int ht_irq[] = {0, 1, 3, 4, 5, 6, 7, 8, 12, 14, 15};

unsigned int local_irq = 1<<0 | 1<<1 | 1<<2 | 1<<7 | 1<<8 | 1<<12;



int plat_set_irq_affinity(struct irq_data *d, const struct cpumask *affinity,

			  bool force)

{

	unsigned int cpu;

	struct cpumask new_affinity;



	/* I/O devices are connected on package-0 */

	cpumask_copy(&new_affinity, affinity);

	for_each_cpu(cpu, affinity)

		if (cpu_data[cpu].package > 0)

			cpumask_clear_cpu(cpu, &new_affinity);



	if (cpumask_empty(&new_affinity))

		return -EINVAL;



	cpumask_copy(d->common->affinity, &new_affinity);



	return IRQ_SET_MASK_OK_NOCOPY;

}



static void ht_irqdispatch(void)

{

	unsigned int i, irq, irq0, irq1;

	static unsigned int dest_cpu = 0;

	unsigned int i, irq;

	struct irq_data *irqd;

	struct cpumask affinity;



	irq = LOONGSON_HT1_INT_VECTOR(0);

	LOONGSON_HT1_INT_VECTOR(0) = irq; /* Acknowledge the IRQs */



	irq0 = irq & local_irq;  /* handled by local core */

	irq1 = irq & ~local_irq; /* balanced by other cores */

	for (i = 0; i < ARRAY_SIZE(ht_irq); i++) {

		if (!(irq & (0x1 << ht_irq[i])))

			continue;



	if (dest_cpu == 0 || !cpu_online(dest_cpu))

		irq0 |= irq1;

	else

		loongson3_send_irq_by_ipi(dest_cpu, irq1);

		/* handled by local core */

		if (local_irq & (0x1 << ht_irq[i])) {

			do_IRQ(ht_irq[i]);

			continue;

		}



	dest_cpu = dest_cpu + 1;

	if (dest_cpu >= num_possible_cpus() || cpu_data[dest_cpu].package > 0)

		dest_cpu = 0;

		irqd = irq_get_irq_data(ht_irq[i]);

		cpumask_and(&affinity, irqd->common->affinity, cpu_active_mask);

		if (cpumask_empty(&affinity)) {

			do_IRQ(ht_irq[i]);

			continue;

		}



	for (i = 0; i < ARRAY_SIZE(ht_irq); i++) {

		if (irq0 & (0x1 << ht_irq[i]))

		irq_cpu[ht_irq[i]] = cpumask_next(irq_cpu[ht_irq[i]], &affinity);

		if (irq_cpu[ht_irq[i]] >= nr_cpu_ids)

			irq_cpu[ht_irq[i]] = cpumask_first(&affinity);



		if (irq_cpu[ht_irq[i]] == 0) {

			do_IRQ(ht_irq[i]);

			continue;

		}



		/* balanced by other cores */

		loongson3_send_irq_by_ipi(irq_cpu[ht_irq[i]], (0x1 << ht_irq[i]));

	}

}
@@ -135,11 +171,16 @@ void irq_router_init(void) 


void __init mach_init_irq(void)

{

	struct irq_chip *chip;



	clear_c0_status(ST0_IM | ST0_BEV);



	irq_router_init();

	mips_cpu_irq_init();

	init_i8259_irqs();

	chip = irq_get_chip(I8259A_IRQ_BASE);

	chip->irq_set_affinity = plat_set_irq_affinity;



	irq_set_chip_and_handler(LOONGSON_UART_IRQ,

			&loongson_irq_chip, handle_level_irq);

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