linux/arch/mips/loongson/loongson-3/irq.c
Huacai Chen c4a987db1b MIPS: Loongson 3: Add CPU hotplug support
Tips of Loongson's CPU hotplug:
1, To fully shutdown a core in Loongson 3, the target core should go to
   CKSEG1 and flush all L1 cache entries at first. Then, another core
   (usually Core 0) can safely disable the clock of the target core. So
   play_dead() call loongson3_play_dead() via CKSEG1 (both uncached and
   unmmaped).
2, The default clocksource of Loongson is MIPS. Since clock source is a
   global device, timekeeping need the CP0' Count registers of each core
   be synchronous. Thus, when a core is up, we use a SMP_ASK_C0COUNT IPI
   to ask Core-0's Count.

Signed-off-by: Huacai Chen <chenhc@lemote.com>
Signed-off-by: Hongliang Tao <taohl@lemote.com>
Signed-off-by: Hua Yan <yanh@lemote.com>
Tested-by: Alex Smith <alex.smith@imgtec.com>
Reviewed-by: Alex Smith <alex.smith@imgtec.com>
Cc: John Crispin <john@phrozen.org>
Cc: Steven J. Hill <Steven.Hill@imgtec.com>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Cc: linux-mips@linux-mips.org
Cc: Fuxin Zhang <zhangfx@lemote.com>
Cc: Zhangjin Wu <wuzhangjin@gmail.com>
Patchwork: https://patchwork.linux-mips.org/patch/6639
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-03-31 18:17:12 +02:00

127 lines
2.8 KiB
C

#include <loongson.h>
#include <irq.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <asm/irq_cpu.h>
#include <asm/i8259.h>
#include <asm/mipsregs.h>
unsigned int ht_irq[] = {1, 3, 4, 5, 6, 7, 8, 12, 14, 15};
static void ht_irqdispatch(void)
{
unsigned int i, irq;
irq = LOONGSON_HT1_INT_VECTOR(0);
LOONGSON_HT1_INT_VECTOR(0) = irq; /* Acknowledge the IRQs */
for (i = 0; i < ARRAY_SIZE(ht_irq); i++) {
if (irq & (0x1 << ht_irq[i]))
do_IRQ(ht_irq[i]);
}
}
void mach_irq_dispatch(unsigned int pending)
{
if (pending & CAUSEF_IP7)
do_IRQ(LOONGSON_TIMER_IRQ);
#if defined(CONFIG_SMP)
else if (pending & CAUSEF_IP6)
loongson3_ipi_interrupt(NULL);
#endif
else if (pending & CAUSEF_IP3)
ht_irqdispatch();
else if (pending & CAUSEF_IP2)
do_IRQ(LOONGSON_UART_IRQ);
else {
pr_err("%s : spurious interrupt\n", __func__);
spurious_interrupt();
}
}
static struct irqaction cascade_irqaction = {
.handler = no_action,
.name = "cascade",
};
static inline void mask_loongson_irq(struct irq_data *d)
{
clear_c0_status(0x100 << (d->irq - MIPS_CPU_IRQ_BASE));
irq_disable_hazard();
/* Workaround: UART IRQ may deliver to any core */
if (d->irq == LOONGSON_UART_IRQ) {
int cpu = smp_processor_id();
LOONGSON_INT_ROUTER_INTENCLR = 1 << 10;
LOONGSON_INT_ROUTER_LPC = 0x10 + (1<<cpu);
}
}
static inline void unmask_loongson_irq(struct irq_data *d)
{
/* Workaround: UART IRQ may deliver to any core */
if (d->irq == LOONGSON_UART_IRQ) {
int cpu = smp_processor_id();
LOONGSON_INT_ROUTER_INTENSET = 1 << 10;
LOONGSON_INT_ROUTER_LPC = 0x10 + (1<<cpu);
}
set_c0_status(0x100 << (d->irq - MIPS_CPU_IRQ_BASE));
irq_enable_hazard();
}
/* For MIPS IRQs which shared by all cores */
static struct irq_chip loongson_irq_chip = {
.name = "Loongson",
.irq_ack = mask_loongson_irq,
.irq_mask = mask_loongson_irq,
.irq_mask_ack = mask_loongson_irq,
.irq_unmask = unmask_loongson_irq,
.irq_eoi = unmask_loongson_irq,
};
void irq_router_init(void)
{
int i;
/* route LPC int to cpu core0 int 0 */
LOONGSON_INT_ROUTER_LPC = LOONGSON_INT_CORE0_INT0;
/* route HT1 int0 ~ int7 to cpu core0 INT1*/
for (i = 0; i < 8; i++)
LOONGSON_INT_ROUTER_HT1(i) = LOONGSON_INT_CORE0_INT1;
/* enable HT1 interrupt */
LOONGSON_HT1_INTN_EN(0) = 0xffffffff;
/* enable router interrupt intenset */
LOONGSON_INT_ROUTER_INTENSET =
LOONGSON_INT_ROUTER_INTEN | (0xffff << 16) | 0x1 << 10;
}
void __init mach_init_irq(void)
{
clear_c0_status(ST0_IM | ST0_BEV);
irq_router_init();
mips_cpu_irq_init();
init_i8259_irqs();
irq_set_chip_and_handler(LOONGSON_UART_IRQ,
&loongson_irq_chip, handle_level_irq);
/* setup HT1 irq */
setup_irq(LOONGSON_HT1_IRQ, &cascade_irqaction);
set_c0_status(STATUSF_IP2 | STATUSF_IP6);
}
#ifdef CONFIG_HOTPLUG_CPU
void fixup_irqs(void)
{
irq_cpu_offline();
clear_c0_status(ST0_IM);
}
#endif