diff options
Diffstat (limited to 'arch/s390/kernel/irq.c')
| -rw-r--r-- | arch/s390/kernel/irq.c | 310 |
1 files changed, 310 insertions, 0 deletions
diff --git a/arch/s390/kernel/irq.c b/arch/s390/kernel/irq.c new file mode 100644 index 000000000..e9d9addfa --- /dev/null +++ b/arch/s390/kernel/irq.c @@ -0,0 +1,310 @@ +/* + * Copyright IBM Corp. 2004, 2011 + * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>, + * Holger Smolinski <Holger.Smolinski@de.ibm.com>, + * Thomas Spatzier <tspat@de.ibm.com>, + * + * This file contains interrupt related functions. + */ + +#include <linux/kernel_stat.h> +#include <linux/interrupt.h> +#include <linux/seq_file.h> +#include <linux/proc_fs.h> +#include <linux/profile.h> +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/ftrace.h> +#include <linux/errno.h> +#include <linux/slab.h> +#include <linux/cpu.h> +#include <linux/irq.h> +#include <asm/irq_regs.h> +#include <asm/cputime.h> +#include <asm/lowcore.h> +#include <asm/irq.h> +#include <asm/hw_irq.h> +#include "entry.h" + +DEFINE_PER_CPU_SHARED_ALIGNED(struct irq_stat, irq_stat); +EXPORT_PER_CPU_SYMBOL_GPL(irq_stat); + +struct irq_class { + int irq; + char *name; + char *desc; +}; + +/* + * The list of "main" irq classes on s390. This is the list of interrupts + * that appear both in /proc/stat ("intr" line) and /proc/interrupts. + * Historically only external and I/O interrupts have been part of /proc/stat. + * We can't add the split external and I/O sub classes since the first field + * in the "intr" line in /proc/stat is supposed to be the sum of all other + * fields. + * Since the external and I/O interrupt fields are already sums we would end + * up with having a sum which accounts each interrupt twice. + */ +static const struct irq_class irqclass_main_desc[NR_IRQS_BASE] = { + {.irq = EXT_INTERRUPT, .name = "EXT"}, + {.irq = IO_INTERRUPT, .name = "I/O"}, + {.irq = THIN_INTERRUPT, .name = "AIO"}, +}; + +/* + * The list of split external and I/O interrupts that appear only in + * /proc/interrupts. + * In addition this list contains non external / I/O events like NMIs. + */ +static const struct irq_class irqclass_sub_desc[] = { + {.irq = IRQEXT_CLK, .name = "CLK", .desc = "[EXT] Clock Comparator"}, + {.irq = IRQEXT_EXC, .name = "EXC", .desc = "[EXT] External Call"}, + {.irq = IRQEXT_EMS, .name = "EMS", .desc = "[EXT] Emergency Signal"}, + {.irq = IRQEXT_TMR, .name = "TMR", .desc = "[EXT] CPU Timer"}, + {.irq = IRQEXT_TLA, .name = "TAL", .desc = "[EXT] Timing Alert"}, + {.irq = IRQEXT_PFL, .name = "PFL", .desc = "[EXT] Pseudo Page Fault"}, + {.irq = IRQEXT_DSD, .name = "DSD", .desc = "[EXT] DASD Diag"}, + {.irq = IRQEXT_VRT, .name = "VRT", .desc = "[EXT] Virtio"}, + {.irq = IRQEXT_SCP, .name = "SCP", .desc = "[EXT] Service Call"}, + {.irq = IRQEXT_IUC, .name = "IUC", .desc = "[EXT] IUCV"}, + {.irq = IRQEXT_CMS, .name = "CMS", .desc = "[EXT] CPU-Measurement: Sampling"}, + {.irq = IRQEXT_CMC, .name = "CMC", .desc = "[EXT] CPU-Measurement: Counter"}, + {.irq = IRQEXT_CMR, .name = "CMR", .desc = "[EXT] CPU-Measurement: RI"}, + {.irq = IRQEXT_FTP, .name = "FTP", .desc = "[EXT] HMC FTP Service"}, + {.irq = IRQIO_CIO, .name = "CIO", .desc = "[I/O] Common I/O Layer Interrupt"}, + {.irq = IRQIO_QAI, .name = "QAI", .desc = "[I/O] QDIO Adapter Interrupt"}, + {.irq = IRQIO_DAS, .name = "DAS", .desc = "[I/O] DASD"}, + {.irq = IRQIO_C15, .name = "C15", .desc = "[I/O] 3215"}, + {.irq = IRQIO_C70, .name = "C70", .desc = "[I/O] 3270"}, + {.irq = IRQIO_TAP, .name = "TAP", .desc = "[I/O] Tape"}, + {.irq = IRQIO_VMR, .name = "VMR", .desc = "[I/O] Unit Record Devices"}, + {.irq = IRQIO_LCS, .name = "LCS", .desc = "[I/O] LCS"}, + {.irq = IRQIO_CTC, .name = "CTC", .desc = "[I/O] CTC"}, + {.irq = IRQIO_APB, .name = "APB", .desc = "[I/O] AP Bus"}, + {.irq = IRQIO_ADM, .name = "ADM", .desc = "[I/O] EADM Subchannel"}, + {.irq = IRQIO_CSC, .name = "CSC", .desc = "[I/O] CHSC Subchannel"}, + {.irq = IRQIO_PCI, .name = "PCI", .desc = "[I/O] PCI Interrupt" }, + {.irq = IRQIO_MSI, .name = "MSI", .desc = "[I/O] MSI Interrupt" }, + {.irq = IRQIO_VIR, .name = "VIR", .desc = "[I/O] Virtual I/O Devices"}, + {.irq = IRQIO_VAI, .name = "VAI", .desc = "[I/O] Virtual I/O Devices AI"}, + {.irq = NMI_NMI, .name = "NMI", .desc = "[NMI] Machine Check"}, + {.irq = CPU_RST, .name = "RST", .desc = "[CPU] CPU Restart"}, +}; + +void __init init_IRQ(void) +{ + BUILD_BUG_ON(ARRAY_SIZE(irqclass_sub_desc) != NR_ARCH_IRQS); + init_cio_interrupts(); + init_airq_interrupts(); + init_ext_interrupts(); +} + +void do_IRQ(struct pt_regs *regs, int irq) +{ + struct pt_regs *old_regs; + + old_regs = set_irq_regs(regs); + irq_enter(); + if (S390_lowcore.int_clock >= S390_lowcore.clock_comparator) + /* Serve timer interrupts first. */ + clock_comparator_work(); + generic_handle_irq(irq); + irq_exit(); + set_irq_regs(old_regs); +} + +/* + * show_interrupts is needed by /proc/interrupts. + */ +int show_interrupts(struct seq_file *p, void *v) +{ + int index = *(loff_t *) v; + int cpu, irq; + + get_online_cpus(); + if (index == 0) { + seq_puts(p, " "); + for_each_online_cpu(cpu) + seq_printf(p, "CPU%d ", cpu); + seq_putc(p, '\n'); + } + if (index < NR_IRQS) { + if (index >= NR_IRQS_BASE) + goto out; + seq_printf(p, "%s: ", irqclass_main_desc[index].name); + irq = irqclass_main_desc[index].irq; + for_each_online_cpu(cpu) + seq_printf(p, "%10u ", kstat_irqs_cpu(irq, cpu)); + seq_putc(p, '\n'); + goto out; + } + for (index = 0; index < NR_ARCH_IRQS; index++) { + seq_printf(p, "%s: ", irqclass_sub_desc[index].name); + irq = irqclass_sub_desc[index].irq; + for_each_online_cpu(cpu) + seq_printf(p, "%10u ", + per_cpu(irq_stat, cpu).irqs[irq]); + if (irqclass_sub_desc[index].desc) + seq_printf(p, " %s", irqclass_sub_desc[index].desc); + seq_putc(p, '\n'); + } +out: + put_online_cpus(); + return 0; +} + +unsigned int arch_dynirq_lower_bound(unsigned int from) +{ + return from < NR_IRQS_BASE ? NR_IRQS_BASE : from; +} + +/* + * Switch to the asynchronous interrupt stack for softirq execution. + */ +void do_softirq_own_stack(void) +{ + unsigned long old, new; + + /* Get current stack pointer. */ + asm volatile("la %0,0(15)" : "=a" (old)); + /* Check against async. stack address range. */ + new = S390_lowcore.async_stack; + if (((new - old) >> (PAGE_SHIFT + THREAD_ORDER)) != 0) { + /* Need to switch to the async. stack. */ + new -= STACK_FRAME_OVERHEAD; + ((struct stack_frame *) new)->back_chain = old; + asm volatile(" la 15,0(%0)\n" + " basr 14,%2\n" + " la 15,0(%1)\n" + : : "a" (new), "a" (old), + "a" (__do_softirq) + : "0", "1", "2", "3", "4", "5", "14", + "cc", "memory" ); + } else { + /* We are already on the async stack. */ + __do_softirq(); + } +} + +/* + * ext_int_hash[index] is the list head for all external interrupts that hash + * to this index. + */ +static struct hlist_head ext_int_hash[32] ____cacheline_aligned; + +struct ext_int_info { + ext_int_handler_t handler; + struct hlist_node entry; + struct rcu_head rcu; + u16 code; +}; + +/* ext_int_hash_lock protects the handler lists for external interrupts */ +static DEFINE_SPINLOCK(ext_int_hash_lock); + +static inline int ext_hash(u16 code) +{ + BUILD_BUG_ON(!is_power_of_2(ARRAY_SIZE(ext_int_hash))); + + return (code + (code >> 9)) & (ARRAY_SIZE(ext_int_hash) - 1); +} + +int register_external_irq(u16 code, ext_int_handler_t handler) +{ + struct ext_int_info *p; + unsigned long flags; + int index; + + p = kmalloc(sizeof(*p), GFP_ATOMIC); + if (!p) + return -ENOMEM; + p->code = code; + p->handler = handler; + index = ext_hash(code); + + spin_lock_irqsave(&ext_int_hash_lock, flags); + hlist_add_head_rcu(&p->entry, &ext_int_hash[index]); + spin_unlock_irqrestore(&ext_int_hash_lock, flags); + return 0; +} +EXPORT_SYMBOL(register_external_irq); + +int unregister_external_irq(u16 code, ext_int_handler_t handler) +{ + struct ext_int_info *p; + unsigned long flags; + int index = ext_hash(code); + + spin_lock_irqsave(&ext_int_hash_lock, flags); + hlist_for_each_entry_rcu(p, &ext_int_hash[index], entry) { + if (p->code == code && p->handler == handler) { + hlist_del_rcu(&p->entry); + kfree_rcu(p, rcu); + } + } + spin_unlock_irqrestore(&ext_int_hash_lock, flags); + return 0; +} +EXPORT_SYMBOL(unregister_external_irq); + +static irqreturn_t do_ext_interrupt(int irq, void *dummy) +{ + struct pt_regs *regs = get_irq_regs(); + struct ext_code ext_code; + struct ext_int_info *p; + int index; + + ext_code = *(struct ext_code *) ®s->int_code; + if (ext_code.code != EXT_IRQ_CLK_COMP) + set_cpu_flag(CIF_NOHZ_DELAY); + + index = ext_hash(ext_code.code); + rcu_read_lock(); + hlist_for_each_entry_rcu(p, &ext_int_hash[index], entry) { + if (unlikely(p->code != ext_code.code)) + continue; + p->handler(ext_code, regs->int_parm, regs->int_parm_long); + } + rcu_read_unlock(); + return IRQ_HANDLED; +} + +static struct irqaction external_interrupt = { + .name = "EXT", + .handler = do_ext_interrupt, +}; + +void __init init_ext_interrupts(void) +{ + int idx; + + for (idx = 0; idx < ARRAY_SIZE(ext_int_hash); idx++) + INIT_HLIST_HEAD(&ext_int_hash[idx]); + + irq_set_chip_and_handler(EXT_INTERRUPT, + &dummy_irq_chip, handle_percpu_irq); + setup_irq(EXT_INTERRUPT, &external_interrupt); +} + +static DEFINE_SPINLOCK(irq_subclass_lock); +static unsigned char irq_subclass_refcount[64]; + +void irq_subclass_register(enum irq_subclass subclass) +{ + spin_lock(&irq_subclass_lock); + if (!irq_subclass_refcount[subclass]) + ctl_set_bit(0, subclass); + irq_subclass_refcount[subclass]++; + spin_unlock(&irq_subclass_lock); +} +EXPORT_SYMBOL(irq_subclass_register); + +void irq_subclass_unregister(enum irq_subclass subclass) +{ + spin_lock(&irq_subclass_lock); + irq_subclass_refcount[subclass]--; + if (!irq_subclass_refcount[subclass]) + ctl_clear_bit(0, subclass); + spin_unlock(&irq_subclass_lock); +} +EXPORT_SYMBOL(irq_subclass_unregister); |