arch/sh/kernel/irq.c

   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:
  38  */
  39 static int show_other_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
  53 int show_interrupts(struct seq_file *p, void *v)
  54 {
  55         unsigned long flags, any_count = 0;
  56         int i = *(loff_t *)v, j, prec;
  57         struct irqaction *action;
  58         struct irq_desc *desc;
  59         struct irq_data *data;
  60         struct irq_chip *chip;
  61
  62         if (i > nr_irqs)
  63                 return 0;
  64
  65         for (prec = 3, j = 1000; prec < 10 && j <= nr_irqs; ++prec)
  66                 j *= 10;
  67
  68         if (i == nr_irqs)
  69                 return show_other_interrupts(p, prec);
  70
  71         if (i == 0) {
  72                 seq_printf(p, "%*s", prec + 8, "");
  73                 for_each_online_cpu(j)
  74                         seq_printf(p, "CPU%-8d", j);
  75                 seq_putc(p, '\n');
  76         }
  77
  78         desc = irq_to_desc(i);
  79         if (!desc)
  80                 return 0;
  81
  82         data = irq_get_irq_data(i);
  83         chip = irq_data_get_irq_chip(data);
  84
  85         raw_spin_lock_irqsave(&desc->lock, flags);
  86         for_each_online_cpu(j)
  87                 any_count |= kstat_irqs_cpu(i, j);
  88         action = desc->action;
  89         if (!action && !any_count)
  90                 goto out;
  91
  92         seq_printf(p, "%*d: ", prec, i);
  93         for_each_online_cpu(j)
  94                 seq_printf(p, "%10u ", kstat_irqs_cpu(i, j));
  95         seq_printf(p, " %14s", chip->name);
  96         seq_printf(p, "-%-8s", desc->name);
  97
  98         if (action) {
  99                 seq_printf(p, "  %s", action->name);
 100                 while ((action = action->next) != NULL)
 101                         seq_printf(p, ", %s", action->name);
 102         }
 103
 104         seq_putc(p, '\n');
 105 out:
 106         raw_spin_unlock_irqrestore(&desc->lock, flags);
 107         return 0;
 108 }
 109 #endif
 110
 111 #ifdef CONFIG_IRQSTACKS
 112 /*
 113  * per-CPU IRQ handling contexts (thread information and stack)
 114  */
 115 union irq_ctx {
 116         struct thread_info      tinfo;
 117         u32                     stack[THREAD_SIZE/sizeof(u32)];
 118 };
 119
 120 static union irq_ctx *hardirq_ctx[NR_CPUS] __read_mostly;
 121 static union irq_ctx *softirq_ctx[NR_CPUS] __read_mostly;
 122
 123 static char softirq_stack[NR_CPUS * THREAD_SIZE] __page_aligned_bss;
 124 static char hardirq_stack[NR_CPUS * THREAD_SIZE] __page_aligned_bss;
 125
 126 static inline void handle_one_irq(unsigned int irq)
 127 {
 128         union irq_ctx *curctx, *irqctx;
 129
 130         curctx = (union irq_ctx *)current_thread_info();
 131         irqctx = hardirq_ctx[smp_processor_id()];
 132
 133         /*
 134          * this is where we switch to the IRQ stack. However, if we are
 135          * already using the IRQ stack (because we interrupted a hardirq
 136          * handler) we can't do that and just have to keep using the
 137          * current stack (which is the irq stack already after all)
 138          */
 139         if (curctx != irqctx) {
 140                 u32 *isp;
 141
 142                 isp = (u32 *)((char *)irqctx + sizeof(*irqctx));
 143                 irqctx->tinfo.task = curctx->tinfo.task;
 144                 irqctx->tinfo.previous_sp = current_stack_pointer;
 145
 146                 /*
 147                  * Copy the softirq bits in preempt_count so that the
 148                  * softirq checks work in the hardirq context.
 149                  */
 150                 irqctx->tinfo.preempt_count =
 151                         (irqctx->tinfo.preempt_count & ~SOFTIRQ_MASK) |
 152                         (curctx->tinfo.preempt_count & SOFTIRQ_MASK);
 153
 154                 __asm__ __volatile__ (
 155                         "mov    %0, r4          \n"
 156                         "mov    r15, r8         \n"
 157                         "jsr    @%1             \n"
 158                         /* swith to the irq stack */
 159                         " mov   %2, r15         \n"
 160                         /* restore the stack (ring zero) */
 161                         "mov    r8, r15         \n"
 162                         : /* no outputs */
 163                         : "r" (irq), "r" (generic_handle_irq), "r" (isp)
 164                         : "memory", "r0", "r1", "r2", "r3", "r4",
 165                           "r5", "r6", "r7", "r8", "t", "pr"
 166                 );
 167         } else
 168                 generic_handle_irq(irq);
 169 }
 170
 171 /*
 172  * allocate per-cpu stacks for hardirq and for softirq processing
 173  */
 174 void irq_ctx_init(int cpu)
 175 {
 176         union irq_ctx *irqctx;
 177
 178         if (hardirq_ctx[cpu])
 179                 return;
 180
 181         irqctx = (union irq_ctx *)&hardirq_stack[cpu * THREAD_SIZE];
 182         irqctx->tinfo.task              = NULL;
 183         irqctx->tinfo.exec_domain       = NULL;
 184         irqctx->tinfo.cpu               = cpu;
 185         irqctx->tinfo.preempt_count     = HARDIRQ_OFFSET;
 186         irqctx->tinfo.addr_limit        = MAKE_MM_SEG(0);
 187
 188         hardirq_ctx[cpu] = irqctx;
 189
 190         irqctx = (union irq_ctx *)&softirq_stack[cpu * THREAD_SIZE];
 191         irqctx->tinfo.task              = NULL;
 192         irqctx->tinfo.exec_domain       = NULL;
 193         irqctx->tinfo.cpu               = cpu;
 194         irqctx->tinfo.preempt_count     = 0;
 195         irqctx->tinfo.addr_limit        = MAKE_MM_SEG(0);
 196
 197         softirq_ctx[cpu] = irqctx;
 198
 199         printk("CPU %u irqstacks, hard=%p soft=%p\n",
 200                 cpu, hardirq_ctx[cpu], softirq_ctx[cpu]);
 201 }
 202
 203 void irq_ctx_exit(int cpu)
 204 {
 205         hardirq_ctx[cpu] = NULL;
 206 }
 207
 208 asmlinkage void do_softirq(void)
 209 {
 210         unsigned long flags;
 211         struct thread_info *curctx;
 212         union irq_ctx *irqctx;
 213         u32 *isp;
 214
 215         if (in_interrupt())
 216                 return;
 217
 218         local_irq_save(flags);
 219
 220         if (local_softirq_pending()) {
 221                 curctx = current_thread_info();
 222                 irqctx = softirq_ctx[smp_processor_id()];
 223                 irqctx->tinfo.task = curctx->task;
 224                 irqctx->tinfo.previous_sp = current_stack_pointer;
 225
 226                 /* build the stack frame on the softirq stack */
 227                 isp = (u32 *)((char *)irqctx + sizeof(*irqctx));
 228
 229                 __asm__ __volatile__ (
 230                         "mov    r15, r9         \n"
 231                         "jsr    @%0             \n"
 232                         /* switch to the softirq stack */
 233                         " mov   %1, r15         \n"
 234                         /* restore the thread stack */
 235                         "mov    r9, r15         \n"
 236                         : /* no outputs */
 237                         : "r" (__do_softirq), "r" (isp)
 238                         : "memory", "r0", "r1", "r2", "r3", "r4",
 239                           "r5", "r6", "r7", "r8", "r9", "r15", "t", "pr"
 240                 );
 241
 242                 /*
 243                  * Shouldnt happen, we returned above if in_interrupt():
 244                  */
 245                 WARN_ON_ONCE(softirq_count());
 246         }
 247
 248         local_irq_restore(flags);
 249 }
 250 #else
 251 static inline void handle_one_irq(unsigned int irq)
 252 {
 253         generic_handle_irq(irq);
 254 }
 255 #endif
 256
 257 asmlinkage __irq_entry int do_IRQ(unsigned int irq, struct pt_regs *regs)
 258 {
 259         struct pt_regs *old_regs = set_irq_regs(regs);
 260
 261         irq_enter();
 262
 263         irq = irq_demux(irq_lookup(irq));
 264
 265         if (irq != NO_IRQ_IGNORE) {
 266                 handle_one_irq(irq);
 267                 irq_finish(irq);
 268         }
 269
 270         irq_exit();
 271
 272         set_irq_regs(old_regs);
 273
 274         return IRQ_HANDLED;
 275 }
 276
 277 void __init init_IRQ(void)
 278 {
 279         plat_irq_setup();
 280
 281         /* Perform the machine specific initialisation */
 282         if (sh_mv.mv_init_irq)
 283                 sh_mv.mv_init_irq();
 284
 285         intc_finalize();
 286
 287         irq_ctx_init(smp_processor_id());
 288 }
 289
 290 #ifdef CONFIG_SPARSE_IRQ
 291 int __init arch_probe_nr_irqs(void)
 292 {
 293         nr_irqs = sh_mv.mv_nr_irqs;
 294         return NR_IRQS_LEGACY;
 295 }
 296 #endif
 297
 298 #ifdef CONFIG_HOTPLUG_CPU
 299 static void route_irq(struct irq_data *data, unsigned int irq, unsigned int cpu)
 300 {
 301         struct irq_desc *desc = irq_to_desc(irq);
 302         struct irq_chip *chip = irq_data_get_irq_chip(data);
 303
 304         printk(KERN_INFO "IRQ%u: moving from cpu%u to cpu%u\n",
 305                irq, data->node, cpu);
 306
 307         raw_spin_lock_irq(&desc->lock);
 308         chip->irq_set_affinity(data, cpumask_of(cpu), false);
 309         raw_spin_unlock_irq(&desc->lock);
 310 }
 311
 312 /*
 313  * The CPU has been marked offline.  Migrate IRQs off this CPU.  If
 314  * the affinity settings do not allow other CPUs, force them onto any
 315  * available CPU.
 316  */
 317 void migrate_irqs(void)
 318 {
 319         unsigned int irq, cpu = smp_processor_id();
 320
 321         for_each_active_irq(irq) {
 322                 struct irq_data *data = irq_get_irq_data(irq);
 323
 324                 if (data->node == cpu) {
 325                         unsigned int newcpu = cpumask_any_and(data->affinity,
 326                                                               cpu_online_mask);
 327                         if (newcpu >= nr_cpu_ids) {
 328                                 if (printk_ratelimit())
 329                                         printk(KERN_INFO "IRQ%u no longer affine to CPU%u\n",
 330                                                irq, cpu);
 331
 332                                 cpumask_setall(data->affinity);
 333                                 newcpu = cpumask_any_and(data->affinity,
 334                                                          cpu_online_mask);
 335                         }
 336
 337                         route_irq(data, irq, newcpu);
 338                 }
 339         }
 340 }
 341 #endif