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 <linux/delay.h> 16 #include <asm/processor.h> 17 #include <asm/machvec.h> 18 #include <asm/uaccess.h> 19 #include <asm/thread_info.h> 20 #include <cpu/mmu_context.h> 21 22 atomic_t irq_err_count; 23 24 /* 25 * 'what should we do if we get a hw irq event on an illegal vector'. 26 * each architecture has to answer this themselves, it doesn't deserve 27 * a generic callback i think. 28 */ 29 void ack_bad_irq(unsigned int irq) 30 { 31 atomic_inc(&irq_err_count); 32 printk("unexpected IRQ trap at vector %02x\n", irq); 33 } 34 35 #if defined(CONFIG_PROC_FS) 36 /* 37 * /proc/interrupts printing for arch specific interrupts 38 */ 39 int arch_show_interrupts(struct seq_file *p, int prec) 40 { 41 int j; 42 43 seq_printf(p, "%*s: ", prec, "NMI"); 44 for_each_online_cpu(j) 45 seq_printf(p, "%10u ", irq_stat[j].__nmi_count); 46 seq_printf(p, " Non-maskable interrupts\n"); 47 48 seq_printf(p, "%*s: %10u\n", prec, "ERR", atomic_read(&irq_err_count)); 49 50 return 0; 51 } 52 #endif 53 54 #ifdef CONFIG_IRQSTACKS 55 /* 56 * per-CPU IRQ handling contexts (thread information and stack) 57 */ 58 union irq_ctx { 59 struct thread_info tinfo; 60 u32 stack[THREAD_SIZE/sizeof(u32)]; 61 }; 62 63 static union irq_ctx *hardirq_ctx[NR_CPUS] __read_mostly; 64 static union irq_ctx *softirq_ctx[NR_CPUS] __read_mostly; 65 66 static char softirq_stack[NR_CPUS * THREAD_SIZE] __page_aligned_bss; 67 static char hardirq_stack[NR_CPUS * THREAD_SIZE] __page_aligned_bss; 68 69 static inline void handle_one_irq(unsigned int irq) 70 { 71 union irq_ctx *curctx, *irqctx; 72 73 curctx = (union irq_ctx *)current_thread_info(); 74 irqctx = hardirq_ctx[smp_processor_id()]; 75 76 /* 77 * this is where we switch to the IRQ stack. However, if we are 78 * already using the IRQ stack (because we interrupted a hardirq 79 * handler) we can't do that and just have to keep using the 80 * current stack (which is the irq stack already after all) 81 */ 82 if (curctx != irqctx) { 83 u32 *isp; 84 85 isp = (u32 *)((char *)irqctx + sizeof(*irqctx)); 86 irqctx->tinfo.task = curctx->tinfo.task; 87 irqctx->tinfo.previous_sp = current_stack_pointer; 88 89 /* 90 * Copy the softirq bits in preempt_count so that the 91 * softirq checks work in the hardirq context. 92 */ 93 irqctx->tinfo.preempt_count = 94 (irqctx->tinfo.preempt_count & ~SOFTIRQ_MASK) | 95 (curctx->tinfo.preempt_count & SOFTIRQ_MASK); 96 97 __asm__ __volatile__ ( 98 "mov %0, r4 \n" 99 "mov r15, r8 \n" 100 "jsr @%1 \n" 101 /* swith to the irq stack */ 102 " mov %2, r15 \n" 103 /* restore the stack (ring zero) */ 104 "mov r8, r15 \n" 105 : /* no outputs */ 106 : "r" (irq), "r" (generic_handle_irq), "r" (isp) 107 : "memory", "r0", "r1", "r2", "r3", "r4", 108 "r5", "r6", "r7", "r8", "t", "pr" 109 ); 110 } else 111 generic_handle_irq(irq); 112 } 113 114 /* 115 * allocate per-cpu stacks for hardirq and for softirq processing 116 */ 117 void irq_ctx_init(int cpu) 118 { 119 union irq_ctx *irqctx; 120 121 if (hardirq_ctx[cpu]) 122 return; 123 124 irqctx = (union irq_ctx *)&hardirq_stack[cpu * THREAD_SIZE]; 125 irqctx->tinfo.task = NULL; 126 irqctx->tinfo.exec_domain = NULL; 127 irqctx->tinfo.cpu = cpu; 128 irqctx->tinfo.preempt_count = HARDIRQ_OFFSET; 129 irqctx->tinfo.addr_limit = MAKE_MM_SEG(0); 130 131 hardirq_ctx[cpu] = irqctx; 132 133 irqctx = (union irq_ctx *)&softirq_stack[cpu * THREAD_SIZE]; 134 irqctx->tinfo.task = NULL; 135 irqctx->tinfo.exec_domain = NULL; 136 irqctx->tinfo.cpu = cpu; 137 irqctx->tinfo.preempt_count = 0; 138 irqctx->tinfo.addr_limit = MAKE_MM_SEG(0); 139 140 softirq_ctx[cpu] = irqctx; 141 142 printk("CPU %u irqstacks, hard=%p soft=%p\n", 143 cpu, hardirq_ctx[cpu], softirq_ctx[cpu]); 144 } 145 146 void irq_ctx_exit(int cpu) 147 { 148 hardirq_ctx[cpu] = NULL; 149 } 150 151 asmlinkage void do_softirq(void) 152 { 153 unsigned long flags; 154 struct thread_info *curctx; 155 union irq_ctx *irqctx; 156 u32 *isp; 157 158 if (in_interrupt()) 159 return; 160 161 local_irq_save(flags); 162 163 if (local_softirq_pending()) { 164 curctx = current_thread_info(); 165 irqctx = softirq_ctx[smp_processor_id()]; 166 irqctx->tinfo.task = curctx->task; 167 irqctx->tinfo.previous_sp = current_stack_pointer; 168 169 /* build the stack frame on the softirq stack */ 170 isp = (u32 *)((char *)irqctx + sizeof(*irqctx)); 171 172 __asm__ __volatile__ ( 173 "mov r15, r9 \n" 174 "jsr @%0 \n" 175 /* switch to the softirq stack */ 176 " mov %1, r15 \n" 177 /* restore the thread stack */ 178 "mov r9, r15 \n" 179 : /* no outputs */ 180 : "r" (__do_softirq), "r" (isp) 181 : "memory", "r0", "r1", "r2", "r3", "r4", 182 "r5", "r6", "r7", "r8", "r9", "r15", "t", "pr" 183 ); 184 185 /* 186 * Shouldn't happen, we returned above if in_interrupt(): 187 */ 188 WARN_ON_ONCE(softirq_count()); 189 } 190 191 local_irq_restore(flags); 192 } 193 #else 194 static inline void handle_one_irq(unsigned int irq) 195 { 196 generic_handle_irq(irq); 197 } 198 #endif 199 200 asmlinkage __irq_entry int do_IRQ(unsigned int irq, struct pt_regs *regs) 201 { 202 struct pt_regs *old_regs = set_irq_regs(regs); 203 204 irq_enter(); 205 206 irq = irq_demux(irq_lookup(irq)); 207 208 if (irq != NO_IRQ_IGNORE) { 209 handle_one_irq(irq); 210 irq_finish(irq); 211 } 212 213 irq_exit(); 214 215 set_irq_regs(old_regs); 216 217 return IRQ_HANDLED; 218 } 219 220 void __init init_IRQ(void) 221 { 222 plat_irq_setup(); 223 224 /* Perform the machine specific initialisation */ 225 if (sh_mv.mv_init_irq) 226 sh_mv.mv_init_irq(); 227 228 intc_finalize(); 229 230 irq_ctx_init(smp_processor_id()); 231 } 232 233 #ifdef CONFIG_SPARSE_IRQ 234 int __init arch_probe_nr_irqs(void) 235 { 236 nr_irqs = sh_mv.mv_nr_irqs; 237 return NR_IRQS_LEGACY; 238 } 239 #endif 240 241 #ifdef CONFIG_HOTPLUG_CPU 242 static void route_irq(struct irq_data *data, unsigned int irq, unsigned int cpu) 243 { 244 struct irq_desc *desc = irq_to_desc(irq); 245 struct irq_chip *chip = irq_data_get_irq_chip(data); 246 247 printk(KERN_INFO "IRQ%u: moving from cpu%u to cpu%u\n", 248 irq, data->node, cpu); 249 250 raw_spin_lock_irq(&desc->lock); 251 chip->irq_set_affinity(data, cpumask_of(cpu), false); 252 raw_spin_unlock_irq(&desc->lock); 253 } 254 255 /* 256 * The CPU has been marked offline. Migrate IRQs off this CPU. If 257 * the affinity settings do not allow other CPUs, force them onto any 258 * available CPU. 259 */ 260 void migrate_irqs(void) 261 { 262 unsigned int irq, cpu = smp_processor_id(); 263 264 for_each_active_irq(irq) { 265 struct irq_data *data = irq_get_irq_data(irq); 266 267 if (data->node == cpu) { 268 unsigned int newcpu = cpumask_any_and(data->affinity, 269 cpu_online_mask); 270 if (newcpu >= nr_cpu_ids) { 271 if (printk_ratelimit()) 272 printk(KERN_INFO "IRQ%u no longer affine to CPU%u\n", 273 irq, cpu); 274 275 cpumask_setall(data->affinity); 276 newcpu = cpumask_any_and(data->affinity, 277 cpu_online_mask); 278 } 279 280 route_irq(data, irq, newcpu); 281 } 282 } 283 } 284 #endif 285