/* * 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 * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2, or (at your option) * any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ #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 <asm/io.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; /* whatever mask they set, we just allow one CPU */ cpu_dest = first_cpu(*dest); return cpu_dest; } static int cpu_set_affinity_irq(struct irq_data *d, const struct cpumask *dest, bool force) { int cpu_dest; cpu_dest = cpu_check_affinity(d, dest); if (cpu_dest < 0) return -1; cpumask_copy(d->affinity, dest); return 0; } #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, #ifdef CONFIG_SMP .irq_set_affinity = cpu_set_affinity_irq, #endif /* 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 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"); #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); #ifdef CONFIG_SMP for_each_online_cpu(j) seq_printf(p, "%10u ", kstat_irqs_cpu(i, j)); #else seq_printf(p, "%10u ", kstat_irqs(i)); #endif 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); cpumask_copy(d->affinity, 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 */ #define IRQ_STACK_SIZE (4096 << 2) /* 16k irq stack size */ union irq_stack_union { unsigned long stack[IRQ_STACK_SIZE/sizeof(unsigned long)]; volatile unsigned int slock[4]; volatile unsigned int lock[1]; }; 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) /* Our stack starts directly behind the thread_info struct. */ unsigned long stack_start = (unsigned long) current_thread_info(); 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; /* 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) 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), 64); /* 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; } void do_softirq_own_stack(void) { execute_on_irq_stack(__do_softirq, 0); } #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(); #ifdef CONFIG_SMP struct irq_desc *desc; 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); #ifdef CONFIG_SMP desc = irq_to_desc(irq); cpumask_copy(&dest, desc->irq_data.affinity); if (irqd_is_per_cpu(&desc->irq_data) && !cpu_isset(smp_processor_id(), dest)) { int cpu = first_cpu(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 struct irqaction timer_action = { .handler = timer_interrupt, .name = "timer", .flags = IRQF_TIMER | IRQF_PERCPU | IRQF_IRQPOLL, }; #ifdef CONFIG_SMP static struct irqaction ipi_action = { .handler = ipi_interrupt, .name = "IPI", .flags = IRQF_PERCPU, }; #endif static void claim_cpu_irqs(void) { 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); setup_irq(TIMER_IRQ, &timer_action); #ifdef CONFIG_SMP irq_set_handler(IPI_IRQ, handle_percpu_irq); setup_irq(IPI_IRQ, &ipi_action); #endif } void __init 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 */ }