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/thread_info.h> 18 #include <cpu/mmu_context.h> 19 20 atomic_t irq_err_count; 21 22 /* 23 * 'what should we do if we get a hw irq event on an illegal vector'. 24 * each architecture has to answer this themselves, it doesn't deserve 25 * a generic callback i think. 26 */ 27 void ack_bad_irq(unsigned int irq) 28 { 29 atomic_inc(&irq_err_count); 30 printk("unexpected IRQ trap at vector %02x\n", irq); 31 } 32 33 #if defined(CONFIG_PROC_FS) 34 /* 35 * /proc/interrupts printing: 36 */ 37 static int show_other_interrupts(struct seq_file *p, int prec) 38 { 39 seq_printf(p, "%*s: %10u\n", prec, "ERR", atomic_read(&irq_err_count)); 40 return 0; 41 } 42 43 int show_interrupts(struct seq_file *p, void *v) 44 { 45 unsigned long flags, any_count = 0; 46 int i = *(loff_t *)v, j, prec; 47 struct irqaction *action; 48 struct irq_desc *desc; 49 50 if (i > nr_irqs) 51 return 0; 52 53 for (prec = 3, j = 1000; prec < 10 && j <= nr_irqs; ++prec) 54 j *= 10; 55 56 if (i == nr_irqs) 57 return show_other_interrupts(p, prec); 58 59 if (i == 0) { 60 seq_printf(p, "%*s", prec + 8, ""); 61 for_each_online_cpu(j) 62 seq_printf(p, "CPU%-8d", j); 63 seq_putc(p, '\n'); 64 } 65 66 desc = irq_to_desc(i); 67 if (!desc) 68 return 0; 69 70 spin_lock_irqsave(&desc->lock, flags); 71 for_each_online_cpu(j) 72 any_count |= kstat_irqs_cpu(i, j); 73 action = desc->action; 74 if (!action && !any_count) 75 goto out; 76 77 seq_printf(p, "%*d: ", prec, i); 78 for_each_online_cpu(j) 79 seq_printf(p, "%10u ", kstat_irqs_cpu(i, j)); 80 seq_printf(p, " %14s", desc->chip->name); 81 seq_printf(p, "-%-8s", desc->name); 82 83 if (action) { 84 seq_printf(p, " %s", action->name); 85 while ((action = action->next) != NULL) 86 seq_printf(p, ", %s", action->name); 87 } 88 89 seq_putc(p, '\n'); 90 out: 91 spin_unlock_irqrestore(&desc->lock, flags); 92 return 0; 93 } 94 #endif 95 96 #ifdef CONFIG_IRQSTACKS 97 /* 98 * per-CPU IRQ handling contexts (thread information and stack) 99 */ 100 union irq_ctx { 101 struct thread_info tinfo; 102 u32 stack[THREAD_SIZE/sizeof(u32)]; 103 }; 104 105 static union irq_ctx *hardirq_ctx[NR_CPUS] __read_mostly; 106 static union irq_ctx *softirq_ctx[NR_CPUS] __read_mostly; 107 #endif 108 109 asmlinkage int do_IRQ(unsigned int irq, struct pt_regs *regs) 110 { 111 struct pt_regs *old_regs = set_irq_regs(regs); 112 #ifdef CONFIG_IRQSTACKS 113 union irq_ctx *curctx, *irqctx; 114 #endif 115 116 irq_enter(); 117 118 #ifdef CONFIG_DEBUG_STACKOVERFLOW 119 /* Debugging check for stack overflow: is there less than 1KB free? */ 120 { 121 long sp; 122 123 __asm__ __volatile__ ("and r15, %0" : 124 "=r" (sp) : "0" (THREAD_SIZE - 1)); 125 126 if (unlikely(sp < (sizeof(struct thread_info) + STACK_WARN))) { 127 printk("do_IRQ: stack overflow: %ld\n", 128 sp - sizeof(struct thread_info)); 129 dump_stack(); 130 } 131 } 132 #endif 133 134 irq = irq_demux(intc_evt2irq(irq)); 135 136 #ifdef CONFIG_IRQSTACKS 137 curctx = (union irq_ctx *)current_thread_info(); 138 irqctx = hardirq_ctx[smp_processor_id()]; 139 140 /* 141 * this is where we switch to the IRQ stack. However, if we are 142 * already using the IRQ stack (because we interrupted a hardirq 143 * handler) we can't do that and just have to keep using the 144 * current stack (which is the irq stack already after all) 145 */ 146 if (curctx != irqctx) { 147 u32 *isp; 148 149 isp = (u32 *)((char *)irqctx + sizeof(*irqctx)); 150 irqctx->tinfo.task = curctx->tinfo.task; 151 irqctx->tinfo.previous_sp = current_stack_pointer; 152 153 /* 154 * Copy the softirq bits in preempt_count so that the 155 * softirq checks work in the hardirq context. 156 */ 157 irqctx->tinfo.preempt_count = 158 (irqctx->tinfo.preempt_count & ~SOFTIRQ_MASK) | 159 (curctx->tinfo.preempt_count & SOFTIRQ_MASK); 160 161 __asm__ __volatile__ ( 162 "mov %0, r4 \n" 163 "mov r15, r8 \n" 164 "jsr @%1 \n" 165 /* swith to the irq stack */ 166 " mov %2, r15 \n" 167 /* restore the stack (ring zero) */ 168 "mov r8, r15 \n" 169 : /* no outputs */ 170 : "r" (irq), "r" (generic_handle_irq), "r" (isp) 171 : "memory", "r0", "r1", "r2", "r3", "r4", 172 "r5", "r6", "r7", "r8", "t", "pr" 173 ); 174 } else 175 #endif 176 generic_handle_irq(irq); 177 178 irq_exit(); 179 180 set_irq_regs(old_regs); 181 return 1; 182 } 183 184 #ifdef CONFIG_IRQSTACKS 185 static char softirq_stack[NR_CPUS * THREAD_SIZE] 186 __attribute__((__section__(".bss.page_aligned"))); 187 188 static char hardirq_stack[NR_CPUS * THREAD_SIZE] 189 __attribute__((__section__(".bss.page_aligned"))); 190 191 /* 192 * allocate per-cpu stacks for hardirq and for softirq processing 193 */ 194 void irq_ctx_init(int cpu) 195 { 196 union irq_ctx *irqctx; 197 198 if (hardirq_ctx[cpu]) 199 return; 200 201 irqctx = (union irq_ctx *)&hardirq_stack[cpu * THREAD_SIZE]; 202 irqctx->tinfo.task = NULL; 203 irqctx->tinfo.exec_domain = NULL; 204 irqctx->tinfo.cpu = cpu; 205 irqctx->tinfo.preempt_count = HARDIRQ_OFFSET; 206 irqctx->tinfo.addr_limit = MAKE_MM_SEG(0); 207 208 hardirq_ctx[cpu] = irqctx; 209 210 irqctx = (union irq_ctx *)&softirq_stack[cpu * THREAD_SIZE]; 211 irqctx->tinfo.task = NULL; 212 irqctx->tinfo.exec_domain = NULL; 213 irqctx->tinfo.cpu = cpu; 214 irqctx->tinfo.preempt_count = 0; 215 irqctx->tinfo.addr_limit = MAKE_MM_SEG(0); 216 217 softirq_ctx[cpu] = irqctx; 218 219 printk("CPU %u irqstacks, hard=%p soft=%p\n", 220 cpu, hardirq_ctx[cpu], softirq_ctx[cpu]); 221 } 222 223 void irq_ctx_exit(int cpu) 224 { 225 hardirq_ctx[cpu] = NULL; 226 } 227 228 asmlinkage void do_softirq(void) 229 { 230 unsigned long flags; 231 struct thread_info *curctx; 232 union irq_ctx *irqctx; 233 u32 *isp; 234 235 if (in_interrupt()) 236 return; 237 238 local_irq_save(flags); 239 240 if (local_softirq_pending()) { 241 curctx = current_thread_info(); 242 irqctx = softirq_ctx[smp_processor_id()]; 243 irqctx->tinfo.task = curctx->task; 244 irqctx->tinfo.previous_sp = current_stack_pointer; 245 246 /* build the stack frame on the softirq stack */ 247 isp = (u32 *)((char *)irqctx + sizeof(*irqctx)); 248 249 __asm__ __volatile__ ( 250 "mov r15, r9 \n" 251 "jsr @%0 \n" 252 /* switch to the softirq stack */ 253 " mov %1, r15 \n" 254 /* restore the thread stack */ 255 "mov r9, r15 \n" 256 : /* no outputs */ 257 : "r" (__do_softirq), "r" (isp) 258 : "memory", "r0", "r1", "r2", "r3", "r4", 259 "r5", "r6", "r7", "r8", "r9", "r15", "t", "pr" 260 ); 261 262 /* 263 * Shouldnt happen, we returned above if in_interrupt(): 264 */ 265 WARN_ON_ONCE(softirq_count()); 266 } 267 268 local_irq_restore(flags); 269 } 270 #endif 271 272 void __init init_IRQ(void) 273 { 274 plat_irq_setup(); 275 276 /* Perform the machine specific initialisation */ 277 if (sh_mv.mv_init_irq) 278 sh_mv.mv_init_irq(); 279 280 irq_ctx_init(smp_processor_id()); 281 } 282 283 #ifdef CONFIG_SPARSE_IRQ 284 int __init arch_probe_nr_irqs(void) 285 { 286 nr_irqs = sh_mv.mv_nr_irqs; 287 return 0; 288 } 289 #endif 290