diff options
Diffstat (limited to 'arch/mips/sibyte/sb1250/irq.c')
| -rw-r--r-- | arch/mips/sibyte/sb1250/irq.c | 318 |
1 files changed, 318 insertions, 0 deletions
diff --git a/arch/mips/sibyte/sb1250/irq.c b/arch/mips/sibyte/sb1250/irq.c new file mode 100644 index 000000000..2f08ad267 --- /dev/null +++ b/arch/mips/sibyte/sb1250/irq.c @@ -0,0 +1,318 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (C) 2000, 2001, 2002, 2003 Broadcom Corporation + */ +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/linkage.h> +#include <linux/interrupt.h> +#include <linux/spinlock.h> +#include <linux/smp.h> +#include <linux/mm.h> +#include <linux/kernel_stat.h> + +#include <asm/errno.h> +#include <asm/signal.h> +#include <asm/time.h> +#include <asm/io.h> + +#include <asm/sibyte/sb1250_regs.h> +#include <asm/sibyte/sb1250_int.h> +#include <asm/sibyte/sb1250_uart.h> +#include <asm/sibyte/sb1250_scd.h> +#include <asm/sibyte/sb1250.h> + +/* + * These are the routines that handle all the low level interrupt stuff. + * Actions handled here are: initialization of the interrupt map, requesting of + * interrupt lines by handlers, dispatching if interrupts to handlers, probing + * for interrupt lines + */ + +#ifdef CONFIG_SIBYTE_HAS_LDT +extern unsigned long ldt_eoi_space; +#endif + +/* Store the CPU id (not the logical number) */ +int sb1250_irq_owner[SB1250_NR_IRQS]; + +static DEFINE_RAW_SPINLOCK(sb1250_imr_lock); + +void sb1250_mask_irq(int cpu, int irq) +{ + unsigned long flags; + u64 cur_ints; + + raw_spin_lock_irqsave(&sb1250_imr_lock, flags); + cur_ints = ____raw_readq(IOADDR(A_IMR_MAPPER(cpu) + + R_IMR_INTERRUPT_MASK)); + cur_ints |= (((u64) 1) << irq); + ____raw_writeq(cur_ints, IOADDR(A_IMR_MAPPER(cpu) + + R_IMR_INTERRUPT_MASK)); + raw_spin_unlock_irqrestore(&sb1250_imr_lock, flags); +} + +void sb1250_unmask_irq(int cpu, int irq) +{ + unsigned long flags; + u64 cur_ints; + + raw_spin_lock_irqsave(&sb1250_imr_lock, flags); + cur_ints = ____raw_readq(IOADDR(A_IMR_MAPPER(cpu) + + R_IMR_INTERRUPT_MASK)); + cur_ints &= ~(((u64) 1) << irq); + ____raw_writeq(cur_ints, IOADDR(A_IMR_MAPPER(cpu) + + R_IMR_INTERRUPT_MASK)); + raw_spin_unlock_irqrestore(&sb1250_imr_lock, flags); +} + +#ifdef CONFIG_SMP +static int sb1250_set_affinity(struct irq_data *d, const struct cpumask *mask, + bool force) +{ + int i = 0, old_cpu, cpu, int_on; + unsigned int irq = d->irq; + u64 cur_ints; + unsigned long flags; + + i = cpumask_first_and(mask, cpu_online_mask); + + /* Convert logical CPU to physical CPU */ + cpu = cpu_logical_map(i); + + /* Protect against other affinity changers and IMR manipulation */ + raw_spin_lock_irqsave(&sb1250_imr_lock, flags); + + /* Swizzle each CPU's IMR (but leave the IP selection alone) */ + old_cpu = sb1250_irq_owner[irq]; + cur_ints = ____raw_readq(IOADDR(A_IMR_MAPPER(old_cpu) + + R_IMR_INTERRUPT_MASK)); + int_on = !(cur_ints & (((u64) 1) << irq)); + if (int_on) { + /* If it was on, mask it */ + cur_ints |= (((u64) 1) << irq); + ____raw_writeq(cur_ints, IOADDR(A_IMR_MAPPER(old_cpu) + + R_IMR_INTERRUPT_MASK)); + } + sb1250_irq_owner[irq] = cpu; + if (int_on) { + /* unmask for the new CPU */ + cur_ints = ____raw_readq(IOADDR(A_IMR_MAPPER(cpu) + + R_IMR_INTERRUPT_MASK)); + cur_ints &= ~(((u64) 1) << irq); + ____raw_writeq(cur_ints, IOADDR(A_IMR_MAPPER(cpu) + + R_IMR_INTERRUPT_MASK)); + } + raw_spin_unlock_irqrestore(&sb1250_imr_lock, flags); + + return 0; +} +#endif + +static void disable_sb1250_irq(struct irq_data *d) +{ + unsigned int irq = d->irq; + + sb1250_mask_irq(sb1250_irq_owner[irq], irq); +} + +static void enable_sb1250_irq(struct irq_data *d) +{ + unsigned int irq = d->irq; + + sb1250_unmask_irq(sb1250_irq_owner[irq], irq); +} + + +static void ack_sb1250_irq(struct irq_data *d) +{ + unsigned int irq = d->irq; +#ifdef CONFIG_SIBYTE_HAS_LDT + u64 pending; + + /* + * If the interrupt was an HT interrupt, now is the time to + * clear it. NOTE: we assume the HT bridge was set up to + * deliver the interrupts to all CPUs (which makes affinity + * changing easier for us) + */ + pending = __raw_readq(IOADDR(A_IMR_REGISTER(sb1250_irq_owner[irq], + R_IMR_LDT_INTERRUPT))); + pending &= ((u64)1 << (irq)); + if (pending) { + int i; + for (i=0; i<NR_CPUS; i++) { + int cpu; +#ifdef CONFIG_SMP + cpu = cpu_logical_map(i); +#else + cpu = i; +#endif + /* + * Clear for all CPUs so an affinity switch + * doesn't find an old status + */ + __raw_writeq(pending, + IOADDR(A_IMR_REGISTER(cpu, + R_IMR_LDT_INTERRUPT_CLR))); + } + + /* + * Generate EOI. For Pass 1 parts, EOI is a nop. For + * Pass 2, the LDT world may be edge-triggered, but + * this EOI shouldn't hurt. If they are + * level-sensitive, the EOI is required. + */ + *(uint32_t *)(ldt_eoi_space+(irq<<16)+(7<<2)) = 0; + } +#endif + sb1250_mask_irq(sb1250_irq_owner[irq], irq); +} + +static struct irq_chip sb1250_irq_type = { + .name = "SB1250-IMR", + .irq_mask_ack = ack_sb1250_irq, + .irq_unmask = enable_sb1250_irq, + .irq_mask = disable_sb1250_irq, +#ifdef CONFIG_SMP + .irq_set_affinity = sb1250_set_affinity +#endif +}; + +void __init init_sb1250_irqs(void) +{ + int i; + + for (i = 0; i < SB1250_NR_IRQS; i++) { + irq_set_chip_and_handler(i, &sb1250_irq_type, + handle_level_irq); + sb1250_irq_owner[i] = 0; + } +} + + +/* + * arch_init_irq is called early in the boot sequence from init/main.c via + * init_IRQ. It is responsible for setting up the interrupt mapper and + * installing the handler that will be responsible for dispatching interrupts + * to the "right" place. + */ +/* + * For now, map all interrupts to IP[2]. We could save + * some cycles by parceling out system interrupts to different + * IP lines, but keep it simple for bringup. We'll also direct + * all interrupts to a single CPU; we should probably route + * PCI and LDT to one cpu and everything else to the other + * to balance the load a bit. + * + * On the second cpu, everything is set to IP5, which is + * ignored, EXCEPT the mailbox interrupt. That one is + * set to IP[2] so it is handled. This is needed so we + * can do cross-cpu function calls, as required by SMP + */ + +#define IMR_IP2_VAL K_INT_MAP_I0 +#define IMR_IP3_VAL K_INT_MAP_I1 +#define IMR_IP4_VAL K_INT_MAP_I2 +#define IMR_IP5_VAL K_INT_MAP_I3 +#define IMR_IP6_VAL K_INT_MAP_I4 + +void __init arch_init_irq(void) +{ + + unsigned int i; + u64 tmp; + unsigned int imask = STATUSF_IP4 | STATUSF_IP3 | STATUSF_IP2 | + STATUSF_IP1 | STATUSF_IP0; + + /* Default everything to IP2 */ + for (i = 0; i < SB1250_NR_IRQS; i++) { /* was I0 */ + __raw_writeq(IMR_IP2_VAL, + IOADDR(A_IMR_REGISTER(0, + R_IMR_INTERRUPT_MAP_BASE) + + (i << 3))); + __raw_writeq(IMR_IP2_VAL, + IOADDR(A_IMR_REGISTER(1, + R_IMR_INTERRUPT_MAP_BASE) + + (i << 3))); + } + + init_sb1250_irqs(); + + /* + * Map the high 16 bits of the mailbox registers to IP[3], for + * inter-cpu messages + */ + /* Was I1 */ + __raw_writeq(IMR_IP3_VAL, + IOADDR(A_IMR_REGISTER(0, R_IMR_INTERRUPT_MAP_BASE) + + (K_INT_MBOX_0 << 3))); + __raw_writeq(IMR_IP3_VAL, + IOADDR(A_IMR_REGISTER(1, R_IMR_INTERRUPT_MAP_BASE) + + (K_INT_MBOX_0 << 3))); + + /* Clear the mailboxes. The firmware may leave them dirty */ + __raw_writeq(0xffffffffffffffffULL, + IOADDR(A_IMR_REGISTER(0, R_IMR_MAILBOX_CLR_CPU))); + __raw_writeq(0xffffffffffffffffULL, + IOADDR(A_IMR_REGISTER(1, R_IMR_MAILBOX_CLR_CPU))); + + /* Mask everything except the mailbox registers for both cpus */ + tmp = ~((u64) 0) ^ (((u64) 1) << K_INT_MBOX_0); + __raw_writeq(tmp, IOADDR(A_IMR_REGISTER(0, R_IMR_INTERRUPT_MASK))); + __raw_writeq(tmp, IOADDR(A_IMR_REGISTER(1, R_IMR_INTERRUPT_MASK))); + + /* Enable necessary IPs, disable the rest */ + change_c0_status(ST0_IM, imask); +} + +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(); + unsigned int pending; + + /* + * What a pain. We have to be really careful saving the upper 32 bits + * of any * register across function calls if we don't want them + * trashed--since were running in -o32, the calling routing never saves + * the full 64 bits of a register across a function call. Being the + * interrupt handler, we're guaranteed that interrupts are disabled + * during this code so we don't have to worry about random interrupts + * blasting the high 32 bits. + */ + + pending = read_c0_cause() & read_c0_status() & ST0_IM; + + if (pending & CAUSEF_IP7) /* CPU performance counter interrupt */ + do_IRQ(MIPS_CPU_IRQ_BASE + 7); + else if (pending & CAUSEF_IP4) + do_IRQ(K_INT_TIMER_0 + cpu); /* sb1250_timer_interrupt() */ + +#ifdef CONFIG_SMP + else if (pending & CAUSEF_IP3) + sb1250_mailbox_interrupt(); +#endif + + else if (pending & CAUSEF_IP2) + dispatch_ip2(); + else + spurious_interrupt(); +} |