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