| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * arch/s390/kernel/irq.c |
| 3 | * |
| 4 | * S390 version |
| 5 | * Copyright (C) 2004 IBM Deutschland Entwicklung GmbH, IBM Corporation |
| 6 | * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com), |
| 7 | * |
| 8 | * This file contains interrupt related functions. |
| 9 | */ |
| 10 | |
| 11 | #include <linux/module.h> |
| 12 | #include <linux/kernel.h> |
| 13 | #include <linux/kernel_stat.h> |
| 14 | #include <linux/interrupt.h> |
| 15 | #include <linux/seq_file.h> |
| 16 | #include <linux/cpu.h> |
| 17 | |
| 18 | /* |
| 19 | * show_interrupts is needed by /proc/interrupts. |
| 20 | */ |
| 21 | int show_interrupts(struct seq_file *p, void *v) |
| 22 | { |
| 23 | static const char *intrclass_names[] = { "EXT", "I/O", }; |
| 24 | int i = *(loff_t *) v, j; |
| 25 | |
| 26 | if (i == 0) { |
| 27 | seq_puts(p, " "); |
| 28 | for_each_online_cpu(j) |
| 29 | seq_printf(p, "CPU%d ",j); |
| 30 | seq_putc(p, '\n'); |
| 31 | } |
| 32 | |
| 33 | if (i < NR_IRQS) { |
| 34 | seq_printf(p, "%s: ", intrclass_names[i]); |
| 35 | #ifndef CONFIG_SMP |
| 36 | seq_printf(p, "%10u ", kstat_irqs(i)); |
| 37 | #else |
| 38 | for_each_online_cpu(j) |
| 39 | seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]); |
| 40 | #endif |
| 41 | seq_putc(p, '\n'); |
| 42 | |
| 43 | } |
| 44 | |
| 45 | return 0; |
| 46 | } |
| 47 | |
| 48 | /* |
| 49 | * For compatibilty only. S/390 specific setup of interrupts et al. is done |
| 50 | * much later in init_channel_subsystem(). |
| 51 | */ |
| 52 | void __init |
| 53 | init_IRQ(void) |
| 54 | { |
| 55 | /* nothing... */ |
| 56 | } |
| 57 | |
| 58 | /* |
| 59 | * Switch to the asynchronous interrupt stack for softirq execution. |
| 60 | */ |
| 61 | extern void __do_softirq(void); |
| 62 | |
| 63 | asmlinkage void do_softirq(void) |
| 64 | { |
| 65 | unsigned long flags, old, new; |
| 66 | |
| 67 | if (in_interrupt()) |
| 68 | return; |
| 69 | |
| 70 | local_irq_save(flags); |
| 71 | |
| 72 | account_system_vtime(current); |
| 73 | |
| 74 | local_bh_disable(); |
| 75 | |
| 76 | if (local_softirq_pending()) { |
| 77 | /* Get current stack pointer. */ |
| 78 | asm volatile("la %0,0(15)" : "=a" (old)); |
| 79 | /* Check against async. stack address range. */ |
| 80 | new = S390_lowcore.async_stack; |
| 81 | if (((new - old) >> (PAGE_SHIFT + THREAD_ORDER)) != 0) { |
| 82 | /* Need to switch to the async. stack. */ |
| 83 | new -= STACK_FRAME_OVERHEAD; |
| 84 | ((struct stack_frame *) new)->back_chain = old; |
| 85 | |
| 86 | asm volatile(" la 15,0(%0)\n" |
| 87 | " basr 14,%2\n" |
| 88 | " la 15,0(%1)\n" |
| 89 | : : "a" (new), "a" (old), |
| 90 | "a" (__do_softirq) |
| 91 | : "0", "1", "2", "3", "4", "5", "14", |
| 92 | "cc", "memory" ); |
| 93 | } else |
| 94 | /* We are already on the async stack. */ |
| 95 | __do_softirq(); |
| 96 | } |
| 97 | |
| 98 | account_system_vtime(current); |
| 99 | |
| 100 | __local_bh_enable(); |
| 101 | |
| 102 | local_irq_restore(flags); |
| 103 | } |
| 104 | |
| 105 | EXPORT_SYMBOL(do_softirq); |