1 /* 2 * linux/arch/sh/kernel/irq.c 3 * 4 * Copyright (C) 1992, 1998 Linus Torvalds, Ingo Molnar 5 * 6 * 7 * SuperH version: Copyright (C) 1999 Niibe Yutaka 8 */ 9 #include <linux/irq.h> 10 #include <linux/interrupt.h> 11 #include <linux/module.h> 12 #include <linux/kernel_stat.h> 13 #include <linux/seq_file.h> 14 #include <asm/processor.h> 15 #include <asm/machvec.h> 16 #include <asm/uaccess.h> 17 #include <asm/dwarf.h> 18 #include <asm/thread_info.h> 19 #include <cpu/mmu_context.h> 20 21 atomic_t irq_err_count; 22 23 /* 24 * 'what should we do if we get a hw irq event on an illegal vector'. 25 * each architecture has to answer this themselves, it doesn't deserve 26 * a generic callback i think. 27 */ 28 void ack_bad_irq(unsigned int irq) 29 { 30 atomic_inc(&irq_err_count); 31 printk("unexpected IRQ trap at vector %02x\n", irq); 32 } 33 34 #if defined(CONFIG_PROC_FS) 35 /* 36 * /proc/interrupts printing: 37 */ 38 static int show_other_interrupts(struct seq_file *p, int prec) 39 { 40 seq_printf(p, "%*s: %10u\n", prec, "ERR", atomic_read(&irq_err_count)); 41 return 0; 42 } 43 44 int show_interrupts(struct seq_file *p, void *v) 45 { 46 unsigned long flags, any_count = 0; 47 int i = *(loff_t *)v, j, prec; 48 struct irqaction *action; 49 struct irq_desc *desc; 50 51 if (i > nr_irqs) 52 return 0; 53 54 for (prec = 3, j = 1000; prec < 10 && j <= nr_irqs; ++prec) 55 j *= 10; 56 57 if (i == nr_irqs) 58 return show_other_interrupts(p, prec); 59 60 if (i == 0) { 61 seq_printf(p, "%*s", prec + 8, ""); 62 for_each_online_cpu(j) 63 seq_printf(p, "CPU%-8d", j); 64 seq_putc(p, '\n'); 65 } 66 67 desc = irq_to_desc(i); 68 if (!desc) 69 return 0; 70 71 spin_lock_irqsave(&desc->lock, flags); 72 for_each_online_cpu(j) 73 any_count |= kstat_irqs_cpu(i, j); 74 action = desc->action; 75 if (!action && !any_count) 76 goto out; 77 78 seq_printf(p, "%*d: ", prec, i); 79 for_each_online_cpu(j) 80 seq_printf(p, "%10u ", kstat_irqs_cpu(i, j)); 81 seq_printf(p, " %14s", desc->chip->name); 82 seq_printf(p, "-%-8s", desc->name); 83 84 if (action) { 85 seq_printf(p, " %s", action->name); 86 while ((action = action->next) != NULL) 87 seq_printf(p, ", %s", action->name); 88 } 89 90 seq_putc(p, '\n'); 91 out: 92 spin_unlock_irqrestore(&desc->lock, flags); 93 return 0; 94 } 95 #endif 96 97 #ifdef CONFIG_IRQSTACKS 98 /* 99 * per-CPU IRQ handling contexts (thread information and stack) 100 */ 101 union irq_ctx { 102 struct thread_info tinfo; 103 u32 stack[THREAD_SIZE/sizeof(u32)]; 104 }; 105 106 static union irq_ctx *hardirq_ctx[NR_CPUS] __read_mostly; 107 static union irq_ctx *softirq_ctx[NR_CPUS] __read_mostly; 108 #endif 109 110 asmlinkage int do_IRQ(unsigned int irq, struct pt_regs *regs) 111 { 112 struct pt_regs *old_regs = set_irq_regs(regs); 113 #ifdef CONFIG_IRQSTACKS 114 union irq_ctx *curctx, *irqctx; 115 #endif 116 117 irq_enter(); 118 irq = irq_demux(intc_evt2irq(irq)); 119 120 #ifdef CONFIG_IRQSTACKS 121 curctx = (union irq_ctx *)current_thread_info(); 122 irqctx = hardirq_ctx[smp_processor_id()]; 123 124 /* 125 * this is where we switch to the IRQ stack. However, if we are 126 * already using the IRQ stack (because we interrupted a hardirq 127 * handler) we can't do that and just have to keep using the 128 * current stack (which is the irq stack already after all) 129 */ 130 if (curctx != irqctx) { 131 u32 *isp; 132 133 isp = (u32 *)((char *)irqctx + sizeof(*irqctx)); 134 irqctx->tinfo.task = curctx->tinfo.task; 135 irqctx->tinfo.previous_sp = current_stack_pointer; 136 137 /* 138 * Copy the softirq bits in preempt_count so that the 139 * softirq checks work in the hardirq context. 140 */ 141 irqctx->tinfo.preempt_count = 142 (irqctx->tinfo.preempt_count & ~SOFTIRQ_MASK) | 143 (curctx->tinfo.preempt_count & SOFTIRQ_MASK); 144 145 __asm__ __volatile__ ( 146 "mov %0, r4 \n" 147 "mov r15, r8 \n" 148 "jsr @%1 \n" 149 /* swith to the irq stack */ 150 " mov %2, r15 \n" 151 /* restore the stack (ring zero) */ 152 "mov r8, r15 \n" 153 : /* no outputs */ 154 : "r" (irq), "r" (generic_handle_irq), "r" (isp) 155 : "memory", "r0", "r1", "r2", "r3", "r4", 156 "r5", "r6", "r7", "r8", "t", "pr" 157 ); 158 } else 159 #endif 160 generic_handle_irq(irq); 161 162 irq_exit(); 163 164 set_irq_regs(old_regs); 165 return 1; 166 } 167 168 #ifdef CONFIG_IRQSTACKS 169 static char softirq_stack[NR_CPUS * THREAD_SIZE] 170 __attribute__((__section__(".bss.page_aligned"))); 171 172 static char hardirq_stack[NR_CPUS * THREAD_SIZE] 173 __attribute__((__section__(".bss.page_aligned"))); 174 175 /* 176 * allocate per-cpu stacks for hardirq and for softirq processing 177 */ 178 void irq_ctx_init(int cpu) 179 { 180 union irq_ctx *irqctx; 181 182 if (hardirq_ctx[cpu]) 183 return; 184 185 irqctx = (union irq_ctx *)&hardirq_stack[cpu * THREAD_SIZE]; 186 irqctx->tinfo.task = NULL; 187 irqctx->tinfo.exec_domain = NULL; 188 irqctx->tinfo.cpu = cpu; 189 irqctx->tinfo.preempt_count = HARDIRQ_OFFSET; 190 irqctx->tinfo.addr_limit = MAKE_MM_SEG(0); 191 192 hardirq_ctx[cpu] = irqctx; 193 194 irqctx = (union irq_ctx *)&softirq_stack[cpu * THREAD_SIZE]; 195 irqctx->tinfo.task = NULL; 196 irqctx->tinfo.exec_domain = NULL; 197 irqctx->tinfo.cpu = cpu; 198 irqctx->tinfo.preempt_count = 0; 199 irqctx->tinfo.addr_limit = MAKE_MM_SEG(0); 200 201 softirq_ctx[cpu] = irqctx; 202 203 printk("CPU %u irqstacks, hard=%p soft=%p\n", 204 cpu, hardirq_ctx[cpu], softirq_ctx[cpu]); 205 } 206 207 void irq_ctx_exit(int cpu) 208 { 209 hardirq_ctx[cpu] = NULL; 210 } 211 212 asmlinkage void do_softirq(void) 213 { 214 unsigned long flags; 215 struct thread_info *curctx; 216 union irq_ctx *irqctx; 217 u32 *isp; 218 219 if (in_interrupt()) 220 return; 221 222 local_irq_save(flags); 223 224 if (local_softirq_pending()) { 225 curctx = current_thread_info(); 226 irqctx = softirq_ctx[smp_processor_id()]; 227 irqctx->tinfo.task = curctx->task; 228 irqctx->tinfo.previous_sp = current_stack_pointer; 229 230 /* build the stack frame on the softirq stack */ 231 isp = (u32 *)((char *)irqctx + sizeof(*irqctx)); 232 233 __asm__ __volatile__ ( 234 "mov r15, r9 \n" 235 "jsr @%0 \n" 236 /* switch to the softirq stack */ 237 " mov %1, r15 \n" 238 /* restore the thread stack */ 239 "mov r9, r15 \n" 240 : /* no outputs */ 241 : "r" (__do_softirq), "r" (isp) 242 : "memory", "r0", "r1", "r2", "r3", "r4", 243 "r5", "r6", "r7", "r8", "r9", "r15", "t", "pr" 244 ); 245 246 /* 247 * Shouldnt happen, we returned above if in_interrupt(): 248 */ 249 WARN_ON_ONCE(softirq_count()); 250 } 251 252 local_irq_restore(flags); 253 } 254 #endif 255 256 void __init init_IRQ(void) 257 { 258 plat_irq_setup(); 259 260 /* Perform the machine specific initialisation */ 261 if (sh_mv.mv_init_irq) 262 sh_mv.mv_init_irq(); 263 264 irq_ctx_init(smp_processor_id()); 265 266 /* This needs to be early, but not too early.. */ 267 dwarf_unwinder_init(); 268 } 269 270 #ifdef CONFIG_SPARSE_IRQ 271 int __init arch_probe_nr_irqs(void) 272 { 273 nr_irqs = sh_mv.mv_nr_irqs; 274 return 0; 275 } 276 #endif 277