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