diff options
Diffstat (limited to 'arch/powerpc/kernel/irq.c')
| -rw-r--r-- | arch/powerpc/kernel/irq.c | 691 |
1 files changed, 691 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c new file mode 100644 index 000000000..45096033d --- /dev/null +++ b/arch/powerpc/kernel/irq.c @@ -0,0 +1,691 @@ +/* + * 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 <cort@fsmlabs.com> + * 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 <linux/export.h> +#include <linux/threads.h> +#include <linux/kernel_stat.h> +#include <linux/signal.h> +#include <linux/sched.h> +#include <linux/ptrace.h> +#include <linux/ioport.h> +#include <linux/interrupt.h> +#include <linux/timex.h> +#include <linux/init.h> +#include <linux/slab.h> +#include <linux/delay.h> +#include <linux/irq.h> +#include <linux/seq_file.h> +#include <linux/cpumask.h> +#include <linux/profile.h> +#include <linux/bitops.h> +#include <linux/list.h> +#include <linux/radix-tree.h> +#include <linux/mutex.h> +#include <linux/pci.h> +#include <linux/debugfs.h> +#include <linux/of.h> +#include <linux/of_irq.h> + +#include <asm/uaccess.h> +#include <asm/io.h> +#include <asm/pgtable.h> +#include <asm/irq.h> +#include <asm/cache.h> +#include <asm/prom.h> +#include <asm/ptrace.h> +#include <asm/machdep.h> +#include <asm/udbg.h> +#include <asm/smp.h> +#include <asm/debug.h> + +#ifdef CONFIG_PPC64 +#include <asm/paca.h> +#include <asm/firmware.h> +#include <asm/lv1call.h> +#endif +#define CREATE_TRACE_POINTS +#include <asm/trace.h> + +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 = this_cpu_ptr(&decrementers_next_tb); + + 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 */ + + /* Check if an hypervisor Maintenance interrupt happened */ + local_paca->irq_happened &= ~PACA_IRQ_HMI; + if (happened & PACA_IRQ_HMI) + return 0xe60; + + /* 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 arch_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_event); + seq_printf(p, " Local timer interrupts for timer event device\n"); + + seq_printf(p, "%*s: ", prec, "LOC"); + for_each_online_cpu(j) + seq_printf(p, "%10u ", per_cpu(irq_stat, j).timer_irqs_others); + seq_printf(p, " Local timer interrupts for others\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, "PMI"); + 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"); + + if (cpu_has_feature(CPU_FTR_HVMODE)) { + seq_printf(p, "%*s: ", prec, "HMI"); + for_each_online_cpu(j) + seq_printf(p, "%10u ", + per_cpu(irq_stat, j).hmi_exceptions); + seq_printf(p, " Hypervisor Maintenance Interrupts\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_event; + + sum += per_cpu(irq_stat, cpu).pmu_irqs; + sum += per_cpu(irq_stat, cpu).mce_exceptions; + sum += per_cpu(irq_stat, cpu).spurious_irqs; + sum += per_cpu(irq_stat, cpu).timer_irqs_others; + sum += per_cpu(irq_stat, cpu).hmi_exceptions; +#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) { + pr_warn("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++)) + pr_err("Cannot set affinity for irq %i\n", irq); + } + + free_cpumask_var(mask); + + local_irq_enable(); + mdelay(1); + local_irq_disable(); +} +#endif + +static inline void check_stack_overflow(void) +{ +#ifdef CONFIG_DEBUG_STACKOVERFLOW + long sp; + + sp = current_stack_pointer() & (THREAD_SIZE-1); + + /* check for stack overflow: is there less than 2KB free? */ + if (unlikely(sp < (sizeof(struct thread_info) + 2048))) { + pr_err("do_IRQ: stack overflow: %ld\n", + sp - sizeof(struct thread_info)); + dump_stack(); + } +#endif +} + +void __do_irq(struct pt_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 to allow perf interrupts */ + may_hard_irq_enable(); + + /* And finally process it */ + if (unlikely(irq == NO_IRQ)) + __this_cpu_inc(irq_stat.spurious_irqs); + else + generic_handle_irq(irq); + + trace_irq_exit(regs); + + irq_exit(); +} + +void do_IRQ(struct pt_regs *regs) +{ + struct pt_regs *old_regs = set_irq_regs(regs); + struct thread_info *curtp, *irqtp, *sirqtp; + + /* Switch to the irq stack to handle this */ + curtp = current_thread_info(); + irqtp = hardirq_ctx[raw_smp_processor_id()]; + sirqtp = softirq_ctx[raw_smp_processor_id()]; + + /* Already there ? */ + if (unlikely(curtp == irqtp || curtp == sirqtp)) { + __do_irq(regs); + set_irq_regs(old_regs); + return; + } + + /* Prepare the thread_info in the irq stack */ + irqtp->task = curtp->task; + irqtp->flags = 0; + + /* Copy the preempt_count so that the [soft]irq checks work. */ + irqtp->preempt_count = curtp->preempt_count; + + /* Switch stack and call */ + call_do_irq(regs, irqtp); + + /* Restore stack limit */ + irqtp->task = NULL; + + /* Copy back updates to the thread_info */ + if (irqtp->flags) + set_bits(irqtp->flags, &curtp->flags); + + 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 +#ifdef CONFIG_SMP + cpu_nr = get_hard_smp_processor_id(i); +#else + cpu_nr = 0; +#endif +#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; + + memset((void *)hardirq_ctx[i], 0, THREAD_SIZE); + tp = hardirq_ctx[i]; + tp->cpu = i; + } +} + +void do_softirq_own_stack(void) +{ + struct thread_info *curtp, *irqtp; + + curtp = current_thread_info(); + irqtp = softirq_ctx[smp_processor_id()]; + irqtp->task = curtp->task; + irqtp->flags = 0; + call_do_softirq(irqtp); + irqtp->task = NULL; + + /* Set any flag that may have been set on the + * alternate stack + */ + if (irqtp->flags) + set_bits(irqtp->flags, &curtp->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 */ |