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/io.h> 15 #include <linux/irq.h> 16 #include <asm/processor.h> 17 #include <asm/uaccess.h> 18 #include <asm/thread_info.h> 19 #include <asm/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 int show_interrupts(struct seq_file *p, void *v) 36 { 37 int i = *(loff_t *) v, j; 38 struct irqaction * action; 39 unsigned long flags; 40 41 if (i == 0) { 42 seq_puts(p, " "); 43 for_each_online_cpu(j) 44 seq_printf(p, "CPU%d ",j); 45 seq_putc(p, '\n'); 46 } 47 48 if (i < NR_IRQS) { 49 spin_lock_irqsave(&irq_desc[i].lock, flags); 50 action = irq_desc[i].action; 51 if (!action) 52 goto unlock; 53 seq_printf(p, "%3d: ",i); 54 for_each_online_cpu(j) 55 seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]); 56 seq_printf(p, " %14s", irq_desc[i].chip->name); 57 seq_printf(p, "-%-8s", irq_desc[i].name); 58 seq_printf(p, " %s", action->name); 59 60 for (action=action->next; action; action = action->next) 61 seq_printf(p, ", %s", action->name); 62 seq_putc(p, '\n'); 63 unlock: 64 spin_unlock_irqrestore(&irq_desc[i].lock, flags); 65 } else if (i == NR_IRQS) 66 seq_printf(p, "Err: %10u\n", atomic_read(&irq_err_count)); 67 68 return 0; 69 } 70 #endif 71 72 #ifdef CONFIG_4KSTACKS 73 /* 74 * per-CPU IRQ handling contexts (thread information and stack) 75 */ 76 union irq_ctx { 77 struct thread_info tinfo; 78 u32 stack[THREAD_SIZE/sizeof(u32)]; 79 }; 80 81 static union irq_ctx *hardirq_ctx[NR_CPUS] __read_mostly; 82 static union irq_ctx *softirq_ctx[NR_CPUS] __read_mostly; 83 #endif 84 85 asmlinkage int do_IRQ(unsigned long r4, unsigned long r5, 86 unsigned long r6, unsigned long r7, 87 struct pt_regs __regs) 88 { 89 struct pt_regs *regs = RELOC_HIDE(&__regs, 0); 90 struct pt_regs *old_regs = set_irq_regs(regs); 91 int irq; 92 #ifdef CONFIG_4KSTACKS 93 union irq_ctx *curctx, *irqctx; 94 #endif 95 96 irq_enter(); 97 98 #ifdef CONFIG_DEBUG_STACKOVERFLOW 99 /* Debugging check for stack overflow: is there less than 1KB free? */ 100 { 101 long sp; 102 103 __asm__ __volatile__ ("and r15, %0" : 104 "=r" (sp) : "0" (THREAD_SIZE - 1)); 105 106 if (unlikely(sp < (sizeof(struct thread_info) + STACK_WARN))) { 107 printk("do_IRQ: stack overflow: %ld\n", 108 sp - sizeof(struct thread_info)); 109 dump_stack(); 110 } 111 } 112 #endif 113 114 #ifdef CONFIG_CPU_HAS_INTEVT 115 irq = evt2irq(ctrl_inl(INTEVT)); 116 #else 117 irq = r4; 118 #endif 119 120 irq = irq_demux(irq); 121 122 #ifdef CONFIG_4KSTACKS 123 curctx = (union irq_ctx *)current_thread_info(); 124 irqctx = hardirq_ctx[smp_processor_id()]; 125 126 /* 127 * this is where we switch to the IRQ stack. However, if we are 128 * already using the IRQ stack (because we interrupted a hardirq 129 * handler) we can't do that and just have to keep using the 130 * current stack (which is the irq stack already after all) 131 */ 132 if (curctx != irqctx) { 133 u32 *isp; 134 135 isp = (u32 *)((char *)irqctx + sizeof(*irqctx)); 136 irqctx->tinfo.task = curctx->tinfo.task; 137 irqctx->tinfo.previous_sp = current_stack_pointer; 138 139 /* 140 * Copy the softirq bits in preempt_count so that the 141 * softirq checks work in the hardirq context. 142 */ 143 irqctx->tinfo.preempt_count = 144 (irqctx->tinfo.preempt_count & ~SOFTIRQ_MASK) | 145 (curctx->tinfo.preempt_count & SOFTIRQ_MASK); 146 147 __asm__ __volatile__ ( 148 "mov %0, r4 \n" 149 "mov r15, r8 \n" 150 "jsr @%1 \n" 151 /* swith to the irq stack */ 152 " mov %2, r15 \n" 153 /* restore the stack (ring zero) */ 154 "mov r8, r15 \n" 155 : /* no outputs */ 156 : "r" (irq), "r" (generic_handle_irq), "r" (isp) 157 : "memory", "r0", "r1", "r2", "r3", "r4", 158 "r5", "r6", "r7", "r8", "t", "pr" 159 ); 160 } else 161 #endif 162 generic_handle_irq(irq); 163 164 irq_exit(); 165 166 set_irq_regs(old_regs); 167 return 1; 168 } 169 170 #ifdef CONFIG_4KSTACKS 171 /* 172 * These should really be __section__(".bss.page_aligned") as well, but 173 * gcc's 3.0 and earlier don't handle that correctly. 174 */ 175 static char softirq_stack[NR_CPUS * THREAD_SIZE] 176 __attribute__((__aligned__(THREAD_SIZE))); 177 178 static char hardirq_stack[NR_CPUS * THREAD_SIZE] 179 __attribute__((__aligned__(THREAD_SIZE))); 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 extern asmlinkage void __do_softirq(void); 219 220 asmlinkage void do_softirq(void) 221 { 222 unsigned long flags; 223 struct thread_info *curctx; 224 union irq_ctx *irqctx; 225 u32 *isp; 226 227 if (in_interrupt()) 228 return; 229 230 local_irq_save(flags); 231 232 if (local_softirq_pending()) { 233 curctx = current_thread_info(); 234 irqctx = softirq_ctx[smp_processor_id()]; 235 irqctx->tinfo.task = curctx->task; 236 irqctx->tinfo.previous_sp = current_stack_pointer; 237 238 /* build the stack frame on the softirq stack */ 239 isp = (u32 *)((char *)irqctx + sizeof(*irqctx)); 240 241 __asm__ __volatile__ ( 242 "mov r15, r9 \n" 243 "jsr @%0 \n" 244 /* switch to the softirq stack */ 245 " mov %1, r15 \n" 246 /* restore the thread stack */ 247 "mov r9, r15 \n" 248 : /* no outputs */ 249 : "r" (__do_softirq), "r" (isp) 250 : "memory", "r0", "r1", "r2", "r3", "r4", 251 "r5", "r6", "r7", "r8", "r9", "r15", "t", "pr" 252 ); 253 254 /* 255 * Shouldnt happen, we returned above if in_interrupt(): 256 */ 257 WARN_ON_ONCE(softirq_count()); 258 } 259 260 local_irq_restore(flags); 261 } 262 EXPORT_SYMBOL(do_softirq); 263 #endif 264 265 void __init init_IRQ(void) 266 { 267 #ifdef CONFIG_CPU_HAS_PINT_IRQ 268 init_IRQ_pint(); 269 #endif 270 271 #ifdef CONFIG_CPU_HAS_INTC2_IRQ 272 init_IRQ_intc2(); 273 #endif 274 275 #ifdef CONFIG_CPU_HAS_IPR_IRQ 276 init_IRQ_ipr(); 277 #endif 278 279 /* Perform the machine specific initialisation */ 280 if (sh_mv.mv_init_irq) 281 sh_mv.mv_init_irq(); 282 283 irq_ctx_init(smp_processor_id()); 284 } 285