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Diffstat (limited to '')
-rw-r--r-- | arch/parisc/kernel/irq.c | 582 |
1 files changed, 582 insertions, 0 deletions
diff --git a/arch/parisc/kernel/irq.c b/arch/parisc/kernel/irq.c new file mode 100644 index 000000000..9ddb2e397 --- /dev/null +++ b/arch/parisc/kernel/irq.c @@ -0,0 +1,582 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Code to handle x86 style IRQs plus some generic interrupt stuff. + * + * Copyright (C) 1992 Linus Torvalds + * Copyright (C) 1994, 1995, 1996, 1997, 1998 Ralf Baechle + * Copyright (C) 1999 SuSE GmbH (Philipp Rumpf, prumpf@tux.org) + * Copyright (C) 1999-2000 Grant Grundler + * Copyright (c) 2005 Matthew Wilcox + */ +#include <linux/bitops.h> +#include <linux/errno.h> +#include <linux/init.h> +#include <linux/interrupt.h> +#include <linux/kernel_stat.h> +#include <linux/seq_file.h> +#include <linux/types.h> +#include <linux/sched/task_stack.h> +#include <asm/io.h> + +#include <asm/softirq_stack.h> +#include <asm/smp.h> +#include <asm/ldcw.h> + +#undef PARISC_IRQ_CR16_COUNTS + +extern irqreturn_t timer_interrupt(int, void *); +extern irqreturn_t ipi_interrupt(int, void *); + +#define EIEM_MASK(irq) (1UL<<(CPU_IRQ_MAX - irq)) + +/* Bits in EIEM correlate with cpu_irq_action[]. +** Numbered *Big Endian*! (ie bit 0 is MSB) +*/ +static volatile unsigned long cpu_eiem = 0; + +/* +** local ACK bitmap ... habitually set to 1, but reset to zero +** between ->ack() and ->end() of the interrupt to prevent +** re-interruption of a processing interrupt. +*/ +static DEFINE_PER_CPU(unsigned long, local_ack_eiem) = ~0UL; + +static void cpu_mask_irq(struct irq_data *d) +{ + unsigned long eirr_bit = EIEM_MASK(d->irq); + + cpu_eiem &= ~eirr_bit; + /* Do nothing on the other CPUs. If they get this interrupt, + * The & cpu_eiem in the do_cpu_irq_mask() ensures they won't + * handle it, and the set_eiem() at the bottom will ensure it + * then gets disabled */ +} + +static void __cpu_unmask_irq(unsigned int irq) +{ + unsigned long eirr_bit = EIEM_MASK(irq); + + cpu_eiem |= eirr_bit; + + /* This is just a simple NOP IPI. But what it does is cause + * all the other CPUs to do a set_eiem(cpu_eiem) at the end + * of the interrupt handler */ + smp_send_all_nop(); +} + +static void cpu_unmask_irq(struct irq_data *d) +{ + __cpu_unmask_irq(d->irq); +} + +void cpu_ack_irq(struct irq_data *d) +{ + unsigned long mask = EIEM_MASK(d->irq); + int cpu = smp_processor_id(); + + /* Clear in EIEM so we can no longer process */ + per_cpu(local_ack_eiem, cpu) &= ~mask; + + /* disable the interrupt */ + set_eiem(cpu_eiem & per_cpu(local_ack_eiem, cpu)); + + /* and now ack it */ + mtctl(mask, 23); +} + +void cpu_eoi_irq(struct irq_data *d) +{ + unsigned long mask = EIEM_MASK(d->irq); + int cpu = smp_processor_id(); + + /* set it in the eiems---it's no longer in process */ + per_cpu(local_ack_eiem, cpu) |= mask; + + /* enable the interrupt */ + set_eiem(cpu_eiem & per_cpu(local_ack_eiem, cpu)); +} + +#ifdef CONFIG_SMP +int cpu_check_affinity(struct irq_data *d, const struct cpumask *dest) +{ + int cpu_dest; + + /* timer and ipi have to always be received on all CPUs */ + if (irqd_is_per_cpu(d)) + return -EINVAL; + + cpu_dest = cpumask_first_and(dest, cpu_online_mask); + if (cpu_dest >= nr_cpu_ids) + cpu_dest = cpumask_first(cpu_online_mask); + + return cpu_dest; +} +#endif + +static struct irq_chip cpu_interrupt_type = { + .name = "CPU", + .irq_mask = cpu_mask_irq, + .irq_unmask = cpu_unmask_irq, + .irq_ack = cpu_ack_irq, + .irq_eoi = cpu_eoi_irq, + /* XXX: Needs to be written. We managed without it so far, but + * we really ought to write it. + */ + .irq_retrigger = NULL, +}; + +DEFINE_PER_CPU_SHARED_ALIGNED(irq_cpustat_t, irq_stat); +#define irq_stats(x) (&per_cpu(irq_stat, x)) + +/* + * /proc/interrupts printing for arch specific interrupts + */ +int arch_show_interrupts(struct seq_file *p, int prec) +{ + int j; + +#ifdef CONFIG_DEBUG_STACKOVERFLOW + seq_printf(p, "%*s: ", prec, "STK"); + for_each_online_cpu(j) + seq_printf(p, "%10u ", irq_stats(j)->kernel_stack_usage); + seq_puts(p, " Kernel stack usage\n"); +# ifdef CONFIG_IRQSTACKS + seq_printf(p, "%*s: ", prec, "IST"); + for_each_online_cpu(j) + seq_printf(p, "%10u ", irq_stats(j)->irq_stack_usage); + seq_puts(p, " Interrupt stack usage\n"); +# endif +#endif +#ifdef CONFIG_SMP + if (num_online_cpus() > 1) { + seq_printf(p, "%*s: ", prec, "RES"); + for_each_online_cpu(j) + seq_printf(p, "%10u ", irq_stats(j)->irq_resched_count); + seq_puts(p, " Rescheduling interrupts\n"); + seq_printf(p, "%*s: ", prec, "CAL"); + for_each_online_cpu(j) + seq_printf(p, "%10u ", irq_stats(j)->irq_call_count); + seq_puts(p, " Function call interrupts\n"); + } +#endif + seq_printf(p, "%*s: ", prec, "UAH"); + for_each_online_cpu(j) + seq_printf(p, "%10u ", irq_stats(j)->irq_unaligned_count); + seq_puts(p, " Unaligned access handler traps\n"); + seq_printf(p, "%*s: ", prec, "FPA"); + for_each_online_cpu(j) + seq_printf(p, "%10u ", irq_stats(j)->irq_fpassist_count); + seq_puts(p, " Floating point assist traps\n"); + seq_printf(p, "%*s: ", prec, "TLB"); + for_each_online_cpu(j) + seq_printf(p, "%10u ", irq_stats(j)->irq_tlb_count); + seq_puts(p, " TLB shootdowns\n"); + return 0; +} + +int show_interrupts(struct seq_file *p, void *v) +{ + int i = *(loff_t *) v, j; + unsigned long flags; + + if (i == 0) { + seq_puts(p, " "); + for_each_online_cpu(j) + seq_printf(p, " CPU%d", j); + +#ifdef PARISC_IRQ_CR16_COUNTS + seq_printf(p, " [min/avg/max] (CPU cycle counts)"); +#endif + seq_putc(p, '\n'); + } + + if (i < NR_IRQS) { + struct irq_desc *desc = irq_to_desc(i); + struct irqaction *action; + + raw_spin_lock_irqsave(&desc->lock, flags); + action = desc->action; + if (!action) + goto skip; + seq_printf(p, "%3d: ", i); + + for_each_online_cpu(j) + seq_printf(p, "%10u ", irq_desc_kstat_cpu(desc, j)); + + seq_printf(p, " %14s", irq_desc_get_chip(desc)->name); +#ifndef PARISC_IRQ_CR16_COUNTS + seq_printf(p, " %s", action->name); + + while ((action = action->next)) + seq_printf(p, ", %s", action->name); +#else + for ( ;action; action = action->next) { + unsigned int k, avg, min, max; + + min = max = action->cr16_hist[0]; + + for (avg = k = 0; k < PARISC_CR16_HIST_SIZE; k++) { + int hist = action->cr16_hist[k]; + + if (hist) { + avg += hist; + } else + break; + + if (hist > max) max = hist; + if (hist < min) min = hist; + } + + avg /= k; + seq_printf(p, " %s[%d/%d/%d]", action->name, + min,avg,max); + } +#endif + + seq_putc(p, '\n'); + skip: + raw_spin_unlock_irqrestore(&desc->lock, flags); + } + + if (i == NR_IRQS) + arch_show_interrupts(p, 3); + + return 0; +} + + + +/* +** The following form a "set": Virtual IRQ, Transaction Address, Trans Data. +** Respectively, these map to IRQ region+EIRR, Processor HPA, EIRR bit. +** +** To use txn_XXX() interfaces, get a Virtual IRQ first. +** Then use that to get the Transaction address and data. +*/ + +int cpu_claim_irq(unsigned int irq, struct irq_chip *type, void *data) +{ + if (irq_has_action(irq)) + return -EBUSY; + if (irq_get_chip(irq) != &cpu_interrupt_type) + return -EBUSY; + + /* for iosapic interrupts */ + if (type) { + irq_set_chip_and_handler(irq, type, handle_percpu_irq); + irq_set_chip_data(irq, data); + __cpu_unmask_irq(irq); + } + return 0; +} + +int txn_claim_irq(int irq) +{ + return cpu_claim_irq(irq, NULL, NULL) ? -1 : irq; +} + +/* + * The bits_wide parameter accommodates the limitations of the HW/SW which + * use these bits: + * Legacy PA I/O (GSC/NIO): 5 bits (architected EIM register) + * V-class (EPIC): 6 bits + * N/L/A-class (iosapic): 8 bits + * PCI 2.2 MSI: 16 bits + * Some PCI devices: 32 bits (Symbios SCSI/ATM/HyperFabric) + * + * On the service provider side: + * o PA 1.1 (and PA2.0 narrow mode) 5-bits (width of EIR register) + * o PA 2.0 wide mode 6-bits (per processor) + * o IA64 8-bits (0-256 total) + * + * So a Legacy PA I/O device on a PA 2.0 box can't use all the bits supported + * by the processor...and the N/L-class I/O subsystem supports more bits than + * PA2.0 has. The first case is the problem. + */ +int txn_alloc_irq(unsigned int bits_wide) +{ + int irq; + + /* never return irq 0 cause that's the interval timer */ + for (irq = CPU_IRQ_BASE + 1; irq <= CPU_IRQ_MAX; irq++) { + if (cpu_claim_irq(irq, NULL, NULL) < 0) + continue; + if ((irq - CPU_IRQ_BASE) >= (1 << bits_wide)) + continue; + return irq; + } + + /* unlikely, but be prepared */ + return -1; +} + + +unsigned long txn_affinity_addr(unsigned int irq, int cpu) +{ +#ifdef CONFIG_SMP + struct irq_data *d = irq_get_irq_data(irq); + irq_data_update_affinity(d, cpumask_of(cpu)); +#endif + + return per_cpu(cpu_data, cpu).txn_addr; +} + + +unsigned long txn_alloc_addr(unsigned int virt_irq) +{ + static int next_cpu = -1; + + next_cpu++; /* assign to "next" CPU we want this bugger on */ + + /* validate entry */ + while ((next_cpu < nr_cpu_ids) && + (!per_cpu(cpu_data, next_cpu).txn_addr || + !cpu_online(next_cpu))) + next_cpu++; + + if (next_cpu >= nr_cpu_ids) + next_cpu = 0; /* nothing else, assign monarch */ + + return txn_affinity_addr(virt_irq, next_cpu); +} + + +unsigned int txn_alloc_data(unsigned int virt_irq) +{ + return virt_irq - CPU_IRQ_BASE; +} + +static inline int eirr_to_irq(unsigned long eirr) +{ + int bit = fls_long(eirr); + return (BITS_PER_LONG - bit) + TIMER_IRQ; +} + +#ifdef CONFIG_IRQSTACKS +/* + * IRQ STACK - used for irq handler + */ +#ifdef CONFIG_64BIT +#define IRQ_STACK_SIZE (4096 << 4) /* 64k irq stack size */ +#else +#define IRQ_STACK_SIZE (4096 << 3) /* 32k irq stack size */ +#endif + +union irq_stack_union { + unsigned long stack[IRQ_STACK_SIZE/sizeof(unsigned long)]; + volatile unsigned int slock[4]; + volatile unsigned int lock[1]; +}; + +static DEFINE_PER_CPU(union irq_stack_union, irq_stack_union) = { + .slock = { 1,1,1,1 }, + }; +#endif + + +int sysctl_panic_on_stackoverflow = 1; + +static inline void stack_overflow_check(struct pt_regs *regs) +{ +#ifdef CONFIG_DEBUG_STACKOVERFLOW + #define STACK_MARGIN (256*6) + + unsigned long stack_start = (unsigned long) task_stack_page(current); + unsigned long sp = regs->gr[30]; + unsigned long stack_usage; + unsigned int *last_usage; + int cpu = smp_processor_id(); + + /* if sr7 != 0, we interrupted a userspace process which we do not want + * to check for stack overflow. We will only check the kernel stack. */ + if (regs->sr[7]) + return; + + /* exit if already in panic */ + if (sysctl_panic_on_stackoverflow < 0) + return; + + /* calculate kernel stack usage */ + stack_usage = sp - stack_start; +#ifdef CONFIG_IRQSTACKS + if (likely(stack_usage <= THREAD_SIZE)) + goto check_kernel_stack; /* found kernel stack */ + + /* check irq stack usage */ + stack_start = (unsigned long) &per_cpu(irq_stack_union, cpu).stack; + stack_usage = sp - stack_start; + + last_usage = &per_cpu(irq_stat.irq_stack_usage, cpu); + if (unlikely(stack_usage > *last_usage)) + *last_usage = stack_usage; + + if (likely(stack_usage < (IRQ_STACK_SIZE - STACK_MARGIN))) + return; + + pr_emerg("stackcheck: %s will most likely overflow irq stack " + "(sp:%lx, stk bottom-top:%lx-%lx)\n", + current->comm, sp, stack_start, stack_start + IRQ_STACK_SIZE); + goto panic_check; + +check_kernel_stack: +#endif + + /* check kernel stack usage */ + last_usage = &per_cpu(irq_stat.kernel_stack_usage, cpu); + + if (unlikely(stack_usage > *last_usage)) + *last_usage = stack_usage; + + if (likely(stack_usage < (THREAD_SIZE - STACK_MARGIN))) + return; + + pr_emerg("stackcheck: %s will most likely overflow kernel stack " + "(sp:%lx, stk bottom-top:%lx-%lx)\n", + current->comm, sp, stack_start, stack_start + THREAD_SIZE); + +#ifdef CONFIG_IRQSTACKS +panic_check: +#endif + if (sysctl_panic_on_stackoverflow) { + sysctl_panic_on_stackoverflow = -1; /* disable further checks */ + panic("low stack detected by irq handler - check messages\n"); + } +#endif +} + +#ifdef CONFIG_IRQSTACKS +/* in entry.S: */ +void call_on_stack(unsigned long p1, void *func, unsigned long new_stack); + +static void execute_on_irq_stack(void *func, unsigned long param1) +{ + union irq_stack_union *union_ptr; + unsigned long irq_stack; + volatile unsigned int *irq_stack_in_use; + + union_ptr = &per_cpu(irq_stack_union, smp_processor_id()); + irq_stack = (unsigned long) &union_ptr->stack; + irq_stack = ALIGN(irq_stack + sizeof(irq_stack_union.slock), + FRAME_ALIGN); /* align for stack frame usage */ + + /* We may be called recursive. If we are already using the irq stack, + * just continue to use it. Use spinlocks to serialize + * the irq stack usage. + */ + irq_stack_in_use = (volatile unsigned int *)__ldcw_align(union_ptr); + if (!__ldcw(irq_stack_in_use)) { + void (*direct_call)(unsigned long p1) = func; + + /* We are using the IRQ stack already. + * Do direct call on current stack. */ + direct_call(param1); + return; + } + + /* This is where we switch to the IRQ stack. */ + call_on_stack(param1, func, irq_stack); + + /* free up irq stack usage. */ + *irq_stack_in_use = 1; +} + +#ifdef CONFIG_SOFTIRQ_ON_OWN_STACK +void do_softirq_own_stack(void) +{ + execute_on_irq_stack(__do_softirq, 0); +} +#endif +#endif /* CONFIG_IRQSTACKS */ + +/* ONLY called from entry.S:intr_extint() */ +void do_cpu_irq_mask(struct pt_regs *regs) +{ + struct pt_regs *old_regs; + unsigned long eirr_val; + int irq, cpu = smp_processor_id(); + struct irq_data *irq_data; +#ifdef CONFIG_SMP + cpumask_t dest; +#endif + + old_regs = set_irq_regs(regs); + local_irq_disable(); + irq_enter(); + + eirr_val = mfctl(23) & cpu_eiem & per_cpu(local_ack_eiem, cpu); + if (!eirr_val) + goto set_out; + irq = eirr_to_irq(eirr_val); + + irq_data = irq_get_irq_data(irq); + + /* Filter out spurious interrupts, mostly from serial port at bootup */ + if (unlikely(!irq_desc_has_action(irq_data_to_desc(irq_data)))) + goto set_out; + +#ifdef CONFIG_SMP + cpumask_copy(&dest, irq_data_get_affinity_mask(irq_data)); + if (irqd_is_per_cpu(irq_data) && + !cpumask_test_cpu(smp_processor_id(), &dest)) { + int cpu = cpumask_first(&dest); + + printk(KERN_DEBUG "redirecting irq %d from CPU %d to %d\n", + irq, smp_processor_id(), cpu); + gsc_writel(irq + CPU_IRQ_BASE, + per_cpu(cpu_data, cpu).hpa); + goto set_out; + } +#endif + stack_overflow_check(regs); + +#ifdef CONFIG_IRQSTACKS + execute_on_irq_stack(&generic_handle_irq, irq); +#else + generic_handle_irq(irq); +#endif /* CONFIG_IRQSTACKS */ + + out: + irq_exit(); + set_irq_regs(old_regs); + return; + + set_out: + set_eiem(cpu_eiem & per_cpu(local_ack_eiem, cpu)); + goto out; +} + +static void claim_cpu_irqs(void) +{ + unsigned long flags = IRQF_TIMER | IRQF_PERCPU | IRQF_IRQPOLL; + int i; + + for (i = CPU_IRQ_BASE; i <= CPU_IRQ_MAX; i++) { + irq_set_chip_and_handler(i, &cpu_interrupt_type, + handle_percpu_irq); + } + + irq_set_handler(TIMER_IRQ, handle_percpu_irq); + if (request_irq(TIMER_IRQ, timer_interrupt, flags, "timer", NULL)) + pr_err("Failed to register timer interrupt\n"); +#ifdef CONFIG_SMP + irq_set_handler(IPI_IRQ, handle_percpu_irq); + if (request_irq(IPI_IRQ, ipi_interrupt, IRQF_PERCPU, "IPI", NULL)) + pr_err("Failed to register IPI interrupt\n"); +#endif +} + +void init_IRQ(void) +{ + local_irq_disable(); /* PARANOID - should already be disabled */ + mtctl(~0UL, 23); /* EIRR : clear all pending external intr */ +#ifdef CONFIG_SMP + if (!cpu_eiem) { + claim_cpu_irqs(); + cpu_eiem = EIEM_MASK(IPI_IRQ) | EIEM_MASK(TIMER_IRQ); + } +#else + claim_cpu_irqs(); + cpu_eiem = EIEM_MASK(TIMER_IRQ); +#endif + set_eiem(cpu_eiem); /* EIEM : enable all external intr */ +} |