/* * Derived from arch/i386/kernel/irq.c * Copyright (C) 1992 Linus Torvalds * Adapted from arch/i386 by Gary Thomas * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org) * Updated and modified by Cort Dougan * Copyright (C) 1996-2001 Cort Dougan * Adapted for Power Macintosh by Paul Mackerras * Copyright (C) 1996 Paul Mackerras (paulus@cs.anu.edu.au) * * 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 of the License, or (at your option) any later version. * * This file contains the code used by various IRQ handling routines: * asking for different IRQ's should be done through these routines * instead of just grabbing them. Thus setups with different IRQ numbers * shouldn't result in any weird surprises, and installing new handlers * should be easier. * * The MPC8xx has an interrupt mask in the SIU. If a bit is set, the * interrupt is _enabled_. As expected, IRQ0 is bit 0 in the 32-bit * mask register (of which only 16 are defined), hence the weird shifting * and complement of the cached_irq_mask. I want to be able to stuff * this right into the SIU SMASK register. * Many of the prep/chrp functions are conditional compiled on CONFIG_8xx * to reduce code space and undefined function references. */ #undef DEBUG #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef CONFIG_PPC64 #include #include #include #endif #define CREATE_TRACE_POINTS #include DEFINE_PER_CPU_SHARED_ALIGNED(irq_cpustat_t, irq_stat); EXPORT_PER_CPU_SYMBOL(irq_stat); int __irq_offset_value; #ifdef CONFIG_PPC32 EXPORT_SYMBOL(__irq_offset_value); atomic_t ppc_n_lost_interrupts; #ifdef CONFIG_TAU_INT extern int tau_initialized; extern int tau_interrupts(int); #endif #endif /* CONFIG_PPC32 */ #ifdef CONFIG_PPC64 int distribute_irqs = 1; static inline notrace unsigned long get_irq_happened(void) { unsigned long happened; __asm__ __volatile__("lbz %0,%1(13)" : "=r" (happened) : "i" (offsetof(struct paca_struct, irq_happened))); return happened; } static inline notrace void set_soft_enabled(unsigned long enable) { __asm__ __volatile__("stb %0,%1(13)" : : "r" (enable), "i" (offsetof(struct paca_struct, soft_enabled))); } static inline notrace int decrementer_check_overflow(void) { u64 now = get_tb_or_rtc(); u64 *next_tb = &__get_cpu_var(decrementers_next_tb); if (now >= *next_tb) set_dec(1); return now >= *next_tb; } /* This is called whenever we are re-enabling interrupts * and returns either 0 (nothing to do) or 500/900/280/a00/e80 if * there's an EE, DEC or DBELL to generate. * * This is called in two contexts: From arch_local_irq_restore() * before soft-enabling interrupts, and from the exception exit * path when returning from an interrupt from a soft-disabled to * a soft enabled context. In both case we have interrupts hard * disabled. * * We take care of only clearing the bits we handled in the * PACA irq_happened field since we can only re-emit one at a * time and we don't want to "lose" one. */ notrace unsigned int __check_irq_replay(void) { /* * We use local_paca rather than get_paca() to avoid all * the debug_smp_processor_id() business in this low level * function */ unsigned char happened = local_paca->irq_happened; /* Clear bit 0 which we wouldn't clear otherwise */ local_paca->irq_happened &= ~PACA_IRQ_HARD_DIS; /* * Force the delivery of pending soft-disabled interrupts on PS3. * Any HV call will have this side effect. */ if (firmware_has_feature(FW_FEATURE_PS3_LV1)) { u64 tmp, tmp2; lv1_get_version_info(&tmp, &tmp2); } /* * We may have missed a decrementer interrupt. We check the * decrementer itself rather than the paca irq_happened field * in case we also had a rollover while hard disabled */ local_paca->irq_happened &= ~PACA_IRQ_DEC; if ((happened & PACA_IRQ_DEC) || decrementer_check_overflow()) return 0x900; /* Finally check if an external interrupt happened */ local_paca->irq_happened &= ~PACA_IRQ_EE; if (happened & PACA_IRQ_EE) return 0x500; #ifdef CONFIG_PPC_BOOK3E /* Finally check if an EPR external interrupt happened * this bit is typically set if we need to handle another * "edge" interrupt from within the MPIC "EPR" handler */ local_paca->irq_happened &= ~PACA_IRQ_EE_EDGE; if (happened & PACA_IRQ_EE_EDGE) return 0x500; local_paca->irq_happened &= ~PACA_IRQ_DBELL; if (happened & PACA_IRQ_DBELL) return 0x280; #else local_paca->irq_happened &= ~PACA_IRQ_DBELL; if (happened & PACA_IRQ_DBELL) { if (cpu_has_feature(CPU_FTR_HVMODE)) return 0xe80; return 0xa00; } #endif /* CONFIG_PPC_BOOK3E */ /* There should be nothing left ! */ BUG_ON(local_paca->irq_happened != 0); return 0; } notrace void arch_local_irq_restore(unsigned long en) { unsigned char irq_happened; unsigned int replay; /* Write the new soft-enabled value */ set_soft_enabled(en); if (!en) return; /* * From this point onward, we can take interrupts, preempt, * etc... unless we got hard-disabled. We check if an event * happened. If none happened, we know we can just return. * * We may have preempted before the check below, in which case * we are checking the "new" CPU instead of the old one. This * is only a problem if an event happened on the "old" CPU. * * External interrupt events will have caused interrupts to * be hard-disabled, so there is no problem, we * cannot have preempted. */ irq_happened = get_irq_happened(); if (!irq_happened) return; /* * We need to hard disable to get a trusted value from * __check_irq_replay(). We also need to soft-disable * again to avoid warnings in there due to the use of * per-cpu variables. * * We know that if the value in irq_happened is exactly 0x01 * then we are already hard disabled (there are other less * common cases that we'll ignore for now), so we skip the * (expensive) mtmsrd. */ if (unlikely(irq_happened != PACA_IRQ_HARD_DIS)) __hard_irq_disable(); #ifdef CONFIG_TRACE_IRQFLAGS else { /* * We should already be hard disabled here. We had bugs * where that wasn't the case so let's dbl check it and * warn if we are wrong. Only do that when IRQ tracing * is enabled as mfmsr() can be costly. */ if (WARN_ON(mfmsr() & MSR_EE)) __hard_irq_disable(); } #endif /* CONFIG_TRACE_IRQFLAG */ set_soft_enabled(0); /* * Check if anything needs to be re-emitted. We haven't * soft-enabled yet to avoid warnings in decrementer_check_overflow * accessing per-cpu variables */ replay = __check_irq_replay(); /* We can soft-enable now */ set_soft_enabled(1); /* * And replay if we have to. This will return with interrupts * hard-enabled. */ if (replay) { __replay_interrupt(replay); return; } /* Finally, let's ensure we are hard enabled */ __hard_irq_enable(); } EXPORT_SYMBOL(arch_local_irq_restore); /* * This is specifically called by assembly code to re-enable interrupts * if they are currently disabled. This is typically called before * schedule() or do_signal() when returning to userspace. We do it * in C to avoid the burden of dealing with lockdep etc... * * NOTE: This is called with interrupts hard disabled but not marked * as such in paca->irq_happened, so we need to resync this. */ void notrace restore_interrupts(void) { if (irqs_disabled()) { local_paca->irq_happened |= PACA_IRQ_HARD_DIS; local_irq_enable(); } else __hard_irq_enable(); } /* * This is a helper to use when about to go into idle low-power * when the latter has the side effect of re-enabling interrupts * (such as calling H_CEDE under pHyp). * * You call this function with interrupts soft-disabled (this is * already the case when ppc_md.power_save is called). The function * will return whether to enter power save or just return. * * In the former case, it will have notified lockdep of interrupts * being re-enabled and generally sanitized the lazy irq state, * and in the latter case it will leave with interrupts hard * disabled and marked as such, so the local_irq_enable() call * in cpu_idle() will properly re-enable everything. */ bool prep_irq_for_idle(void) { /* * First we need to hard disable to ensure no interrupt * occurs before we effectively enter the low power state */ hard_irq_disable(); /* * If anything happened while we were soft-disabled, * we return now and do not enter the low power state. */ if (lazy_irq_pending()) return false; /* Tell lockdep we are about to re-enable */ trace_hardirqs_on(); /* * Mark interrupts as soft-enabled and clear the * PACA_IRQ_HARD_DIS from the pending mask since we * are about to hard enable as well as a side effect * of entering the low power state. */ local_paca->irq_happened &= ~PACA_IRQ_HARD_DIS; local_paca->soft_enabled = 1; /* Tell the caller to enter the low power state */ return true; } #endif /* CONFIG_PPC64 */ int arch_show_interrupts(struct seq_file *p, int prec) { int j; #if defined(CONFIG_PPC32) && defined(CONFIG_TAU_INT) if (tau_initialized) { seq_printf(p, "%*s: ", prec, "TAU"); for_each_online_cpu(j) seq_printf(p, "%10u ", tau_interrupts(j)); seq_puts(p, " PowerPC Thermal Assist (cpu temp)\n"); } #endif /* CONFIG_PPC32 && CONFIG_TAU_INT */ seq_printf(p, "%*s: ", prec, "LOC"); for_each_online_cpu(j) seq_printf(p, "%10u ", per_cpu(irq_stat, j).timer_irqs); seq_printf(p, " Local timer interrupts\n"); seq_printf(p, "%*s: ", prec, "SPU"); for_each_online_cpu(j) seq_printf(p, "%10u ", per_cpu(irq_stat, j).spurious_irqs); seq_printf(p, " Spurious interrupts\n"); seq_printf(p, "%*s: ", prec, "CNT"); for_each_online_cpu(j) seq_printf(p, "%10u ", per_cpu(irq_stat, j).pmu_irqs); seq_printf(p, " Performance monitoring interrupts\n"); seq_printf(p, "%*s: ", prec, "MCE"); for_each_online_cpu(j) seq_printf(p, "%10u ", per_cpu(irq_stat, j).mce_exceptions); seq_printf(p, " Machine check exceptions\n"); #ifdef CONFIG_PPC_DOORBELL if (cpu_has_feature(CPU_FTR_DBELL)) { seq_printf(p, "%*s: ", prec, "DBL"); for_each_online_cpu(j) seq_printf(p, "%10u ", per_cpu(irq_stat, j).doorbell_irqs); seq_printf(p, " Doorbell interrupts\n"); } #endif return 0; } /* * /proc/stat helpers */ u64 arch_irq_stat_cpu(unsigned int cpu) { u64 sum = per_cpu(irq_stat, cpu).timer_irqs; sum += per_cpu(irq_stat, cpu).pmu_irqs; sum += per_cpu(irq_stat, cpu).mce_exceptions; sum += per_cpu(irq_stat, cpu).spurious_irqs; #ifdef CONFIG_PPC_DOORBELL sum += per_cpu(irq_stat, cpu).doorbell_irqs; #endif return sum; } #ifdef CONFIG_HOTPLUG_CPU void migrate_irqs(void) { struct irq_desc *desc; unsigned int irq; static int warned; cpumask_var_t mask; const struct cpumask *map = cpu_online_mask; alloc_cpumask_var(&mask, GFP_KERNEL); for_each_irq_desc(irq, desc) { struct irq_data *data; struct irq_chip *chip; data = irq_desc_get_irq_data(desc); if (irqd_is_per_cpu(data)) continue; chip = irq_data_get_irq_chip(data); cpumask_and(mask, data->affinity, map); if (cpumask_any(mask) >= nr_cpu_ids) { printk("Breaking affinity for irq %i\n", irq); cpumask_copy(mask, map); } if (chip->irq_set_affinity) chip->irq_set_affinity(data, mask, true); else if (desc->action && !(warned++)) printk("Cannot set affinity for irq %i\n", irq); } free_cpumask_var(mask); local_irq_enable(); mdelay(1); local_irq_disable(); } #endif static inline void handle_one_irq(unsigned int irq) { struct thread_info *curtp, *irqtp; unsigned long saved_sp_limit; struct irq_desc *desc; desc = irq_to_desc(irq); if (!desc) return; /* Switch to the irq stack to handle this */ curtp = current_thread_info(); irqtp = hardirq_ctx[smp_processor_id()]; if (curtp == irqtp) { /* We're already on the irq stack, just handle it */ desc->handle_irq(irq, desc); return; } saved_sp_limit = current->thread.ksp_limit; irqtp->task = curtp->task; irqtp->flags = 0; /* Copy the softirq bits in preempt_count so that the * softirq checks work in the hardirq context. */ irqtp->preempt_count = (irqtp->preempt_count & ~SOFTIRQ_MASK) | (curtp->preempt_count & SOFTIRQ_MASK); current->thread.ksp_limit = (unsigned long)irqtp + _ALIGN_UP(sizeof(struct thread_info), 16); call_handle_irq(irq, desc, irqtp, desc->handle_irq); current->thread.ksp_limit = saved_sp_limit; irqtp->task = NULL; /* Set any flag that may have been set on the * alternate stack */ if (irqtp->flags) set_bits(irqtp->flags, &curtp->flags); } static inline void check_stack_overflow(void) { #ifdef CONFIG_DEBUG_STACKOVERFLOW long sp; sp = __get_SP() & (THREAD_SIZE-1); /* check for stack overflow: is there less than 2KB free? */ if (unlikely(sp < (sizeof(struct thread_info) + 2048))) { printk("do_IRQ: stack overflow: %ld\n", sp - sizeof(struct thread_info)); dump_stack(); } #endif } void do_IRQ(struct pt_regs *regs) { struct pt_regs *old_regs = set_irq_regs(regs); unsigned int irq; irq_enter(); trace_irq_entry(regs); check_stack_overflow(); /* * Query the platform PIC for the interrupt & ack it. * * This will typically lower the interrupt line to the CPU */ irq = ppc_md.get_irq(); /* We can hard enable interrupts now */ may_hard_irq_enable(); /* And finally process it */ if (irq != NO_IRQ) handle_one_irq(irq); else __get_cpu_var(irq_stat).spurious_irqs++; trace_irq_exit(regs); irq_exit(); set_irq_regs(old_regs); } void __init init_IRQ(void) { if (ppc_md.init_IRQ) ppc_md.init_IRQ(); exc_lvl_ctx_init(); irq_ctx_init(); } #if defined(CONFIG_BOOKE) || defined(CONFIG_40x) struct thread_info *critirq_ctx[NR_CPUS] __read_mostly; struct thread_info *dbgirq_ctx[NR_CPUS] __read_mostly; struct thread_info *mcheckirq_ctx[NR_CPUS] __read_mostly; void exc_lvl_ctx_init(void) { struct thread_info *tp; int i, cpu_nr; for_each_possible_cpu(i) { #ifdef CONFIG_PPC64 cpu_nr = i; #else cpu_nr = get_hard_smp_processor_id(i); #endif memset((void *)critirq_ctx[cpu_nr], 0, THREAD_SIZE); tp = critirq_ctx[cpu_nr]; tp->cpu = cpu_nr; tp->preempt_count = 0; #ifdef CONFIG_BOOKE memset((void *)dbgirq_ctx[cpu_nr], 0, THREAD_SIZE); tp = dbgirq_ctx[cpu_nr]; tp->cpu = cpu_nr; tp->preempt_count = 0; memset((void *)mcheckirq_ctx[cpu_nr], 0, THREAD_SIZE); tp = mcheckirq_ctx[cpu_nr]; tp->cpu = cpu_nr; tp->preempt_count = HARDIRQ_OFFSET; #endif } } #endif struct thread_info *softirq_ctx[NR_CPUS] __read_mostly; struct thread_info *hardirq_ctx[NR_CPUS] __read_mostly; void irq_ctx_init(void) { struct thread_info *tp; int i; for_each_possible_cpu(i) { memset((void *)softirq_ctx[i], 0, THREAD_SIZE); tp = softirq_ctx[i]; tp->cpu = i; tp->preempt_count = 0; memset((void *)hardirq_ctx[i], 0, THREAD_SIZE); tp = hardirq_ctx[i]; tp->cpu = i; tp->preempt_count = HARDIRQ_OFFSET; } } static inline void do_softirq_onstack(void) { struct thread_info *curtp, *irqtp; unsigned long saved_sp_limit = current->thread.ksp_limit; curtp = current_thread_info(); irqtp = softirq_ctx[smp_processor_id()]; irqtp->task = curtp->task; irqtp->flags = 0; current->thread.ksp_limit = (unsigned long)irqtp + _ALIGN_UP(sizeof(struct thread_info), 16); call_do_softirq(irqtp); current->thread.ksp_limit = saved_sp_limit; irqtp->task = NULL; /* Set any flag that may have been set on the * alternate stack */ if (irqtp->flags) set_bits(irqtp->flags, &curtp->flags); } void do_softirq(void) { unsigned long flags; if (in_interrupt()) return; local_irq_save(flags); if (local_softirq_pending()) do_softirq_onstack(); local_irq_restore(flags); } irq_hw_number_t virq_to_hw(unsigned int virq) { struct irq_data *irq_data = irq_get_irq_data(virq); return WARN_ON(!irq_data) ? 0 : irq_data->hwirq; } EXPORT_SYMBOL_GPL(virq_to_hw); #ifdef CONFIG_SMP int irq_choose_cpu(const struct cpumask *mask) { int cpuid; if (cpumask_equal(mask, cpu_online_mask)) { static int irq_rover; static DEFINE_RAW_SPINLOCK(irq_rover_lock); unsigned long flags; /* Round-robin distribution... */ do_round_robin: raw_spin_lock_irqsave(&irq_rover_lock, flags); irq_rover = cpumask_next(irq_rover, cpu_online_mask); if (irq_rover >= nr_cpu_ids) irq_rover = cpumask_first(cpu_online_mask); cpuid = irq_rover; raw_spin_unlock_irqrestore(&irq_rover_lock, flags); } else { cpuid = cpumask_first_and(mask, cpu_online_mask); if (cpuid >= nr_cpu_ids) goto do_round_robin; } return get_hard_smp_processor_id(cpuid); } #else int irq_choose_cpu(const struct cpumask *mask) { return hard_smp_processor_id(); } #endif int arch_early_irq_init(void) { return 0; } #ifdef CONFIG_PPC64 static int __init setup_noirqdistrib(char *str) { distribute_irqs = 0; return 1; } __setup("noirqdistrib", setup_noirqdistrib); #endif /* CONFIG_PPC64 */