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 <linux/ftrace.h> 15 #include <asm/processor.h> 16 #include <asm/machvec.h> 17 #include <asm/uaccess.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 int j; 41 42 seq_printf(p, "%*s: ", prec, "NMI"); 43 for_each_online_cpu(j) 44 seq_printf(p, "%10u ", irq_stat[j].__nmi_count); 45 seq_printf(p, " Non-maskable interrupts\n"); 46 47 seq_printf(p, "%*s: %10u\n", prec, "ERR", atomic_read(&irq_err_count)); 48 49 return 0; 50 } 51 52 int show_interrupts(struct seq_file *p, void *v) 53 { 54 unsigned long flags, any_count = 0; 55 int i = *(loff_t *)v, j, prec; 56 struct irqaction *action; 57 struct irq_desc *desc; 58 59 if (i > nr_irqs) 60 return 0; 61 62 for (prec = 3, j = 1000; prec < 10 && j <= nr_irqs; ++prec) 63 j *= 10; 64 65 if (i == nr_irqs) 66 return show_other_interrupts(p, prec); 67 68 if (i == 0) { 69 seq_printf(p, "%*s", prec + 8, ""); 70 for_each_online_cpu(j) 71 seq_printf(p, "CPU%-8d", j); 72 seq_putc(p, '\n'); 73 } 74 75 desc = irq_to_desc(i); 76 if (!desc) 77 return 0; 78 79 raw_spin_lock_irqsave(&desc->lock, flags); 80 for_each_online_cpu(j) 81 any_count |= kstat_irqs_cpu(i, j); 82 action = desc->action; 83 if (!action && !any_count) 84 goto out; 85 86 seq_printf(p, "%*d: ", prec, i); 87 for_each_online_cpu(j) 88 seq_printf(p, "%10u ", kstat_irqs_cpu(i, j)); 89 seq_printf(p, " %14s", desc->chip->name); 90 seq_printf(p, "-%-8s", desc->name); 91 92 if (action) { 93 seq_printf(p, " %s", action->name); 94 while ((action = action->next) != NULL) 95 seq_printf(p, ", %s", action->name); 96 } 97 98 seq_putc(p, '\n'); 99 out: 100 raw_spin_unlock_irqrestore(&desc->lock, flags); 101 return 0; 102 } 103 #endif 104 105 #ifdef CONFIG_IRQSTACKS 106 /* 107 * per-CPU IRQ handling contexts (thread information and stack) 108 */ 109 union irq_ctx { 110 struct thread_info tinfo; 111 u32 stack[THREAD_SIZE/sizeof(u32)]; 112 }; 113 114 static union irq_ctx *hardirq_ctx[NR_CPUS] __read_mostly; 115 static union irq_ctx *softirq_ctx[NR_CPUS] __read_mostly; 116 #endif 117 118 asmlinkage __irq_entry int do_IRQ(unsigned int irq, struct pt_regs *regs) 119 { 120 struct pt_regs *old_regs = set_irq_regs(regs); 121 #ifdef CONFIG_IRQSTACKS 122 union irq_ctx *curctx, *irqctx; 123 #endif 124 125 irq_enter(); 126 irq = irq_demux(irq); 127 128 #ifdef CONFIG_IRQSTACKS 129 curctx = (union irq_ctx *)current_thread_info(); 130 irqctx = hardirq_ctx[smp_processor_id()]; 131 132 /* 133 * this is where we switch to the IRQ stack. However, if we are 134 * already using the IRQ stack (because we interrupted a hardirq 135 * handler) we can't do that and just have to keep using the 136 * current stack (which is the irq stack already after all) 137 */ 138 if (curctx != irqctx) { 139 u32 *isp; 140 141 isp = (u32 *)((char *)irqctx + sizeof(*irqctx)); 142 irqctx->tinfo.task = curctx->tinfo.task; 143 irqctx->tinfo.previous_sp = current_stack_pointer; 144 145 /* 146 * Copy the softirq bits in preempt_count so that the 147 * softirq checks work in the hardirq context. 148 */ 149 irqctx->tinfo.preempt_count = 150 (irqctx->tinfo.preempt_count & ~SOFTIRQ_MASK) | 151 (curctx->tinfo.preempt_count & SOFTIRQ_MASK); 152 153 __asm__ __volatile__ ( 154 "mov %0, r4 \n" 155 "mov r15, r8 \n" 156 "jsr @%1 \n" 157 /* swith to the irq stack */ 158 " mov %2, r15 \n" 159 /* restore the stack (ring zero) */ 160 "mov r8, r15 \n" 161 : /* no outputs */ 162 : "r" (irq), "r" (generic_handle_irq), "r" (isp) 163 : "memory", "r0", "r1", "r2", "r3", "r4", 164 "r5", "r6", "r7", "r8", "t", "pr" 165 ); 166 } else 167 #endif 168 generic_handle_irq(irq); 169 170 irq_exit(); 171 172 set_irq_regs(old_regs); 173 return 1; 174 } 175 176 #ifdef CONFIG_IRQSTACKS 177 static char softirq_stack[NR_CPUS * THREAD_SIZE] __page_aligned_bss; 178 179 static char hardirq_stack[NR_CPUS * THREAD_SIZE] __page_aligned_bss; 180 181 /* 182 * allocate per-cpu stacks for hardirq and for softirq processing 183 */ 184 void irq_ctx_init(int cpu) 185 { 186 union irq_ctx *irqctx; 187 188 if (hardirq_ctx[cpu]) 189 return; 190 191 irqctx = (union irq_ctx *)&hardirq_stack[cpu * THREAD_SIZE]; 192 irqctx->tinfo.task = NULL; 193 irqctx->tinfo.exec_domain = NULL; 194 irqctx->tinfo.cpu = cpu; 195 irqctx->tinfo.preempt_count = HARDIRQ_OFFSET; 196 irqctx->tinfo.addr_limit = MAKE_MM_SEG(0); 197 198 hardirq_ctx[cpu] = irqctx; 199 200 irqctx = (union irq_ctx *)&softirq_stack[cpu * THREAD_SIZE]; 201 irqctx->tinfo.task = NULL; 202 irqctx->tinfo.exec_domain = NULL; 203 irqctx->tinfo.cpu = cpu; 204 irqctx->tinfo.preempt_count = 0; 205 irqctx->tinfo.addr_limit = MAKE_MM_SEG(0); 206 207 softirq_ctx[cpu] = irqctx; 208 209 printk("CPU %u irqstacks, hard=%p soft=%p\n", 210 cpu, hardirq_ctx[cpu], softirq_ctx[cpu]); 211 } 212 213 void irq_ctx_exit(int cpu) 214 { 215 hardirq_ctx[cpu] = NULL; 216 } 217 218 asmlinkage void do_softirq(void) 219 { 220 unsigned long flags; 221 struct thread_info *curctx; 222 union irq_ctx *irqctx; 223 u32 *isp; 224 225 if (in_interrupt()) 226 return; 227 228 local_irq_save(flags); 229 230 if (local_softirq_pending()) { 231 curctx = current_thread_info(); 232 irqctx = softirq_ctx[smp_processor_id()]; 233 irqctx->tinfo.task = curctx->task; 234 irqctx->tinfo.previous_sp = current_stack_pointer; 235 236 /* build the stack frame on the softirq stack */ 237 isp = (u32 *)((char *)irqctx + sizeof(*irqctx)); 238 239 __asm__ __volatile__ ( 240 "mov r15, r9 \n" 241 "jsr @%0 \n" 242 /* switch to the softirq stack */ 243 " mov %1, r15 \n" 244 /* restore the thread stack */ 245 "mov r9, r15 \n" 246 : /* no outputs */ 247 : "r" (__do_softirq), "r" (isp) 248 : "memory", "r0", "r1", "r2", "r3", "r4", 249 "r5", "r6", "r7", "r8", "r9", "r15", "t", "pr" 250 ); 251 252 /* 253 * Shouldnt happen, we returned above if in_interrupt(): 254 */ 255 WARN_ON_ONCE(softirq_count()); 256 } 257 258 local_irq_restore(flags); 259 } 260 #endif 261 262 void __init init_IRQ(void) 263 { 264 plat_irq_setup(); 265 266 /* 267 * Pin any of the legacy IRQ vectors that haven't already been 268 * grabbed by the platform 269 */ 270 reserve_irq_legacy(); 271 272 /* Perform the machine specific initialisation */ 273 if (sh_mv.mv_init_irq) 274 sh_mv.mv_init_irq(); 275 276 irq_ctx_init(smp_processor_id()); 277 } 278 279 #ifdef CONFIG_SPARSE_IRQ 280 int __init arch_probe_nr_irqs(void) 281 { 282 nr_irqs = sh_mv.mv_nr_irqs; 283 return 0; 284 } 285 #endif 286