arch/sh/kernel/smp.c

   1 /*
   2  * arch/sh/kernel/smp.c
   3  *
   4  * SMP support for the SuperH processors.
   5  *
   6  * Copyright (C) 2002 - 2010 Paul Mundt
   7  * Copyright (C) 2006 - 2007 Akio Idehara
   8  *
   9  * This file is subject to the terms and conditions of the GNU General Public
  10  * License.  See the file "COPYING" in the main directory of this archive
  11  * for more details.
  12  */
  13 #include <linux/err.h>
  14 #include <linux/cache.h>
  15 #include <linux/cpumask.h>
  16 #include <linux/delay.h>
  17 #include <linux/init.h>
  18 #include <linux/spinlock.h>
  19 #include <linux/mm.h>
  20 #include <linux/module.h>
  21 #include <linux/cpu.h>
  22 #include <linux/interrupt.h>
  23 #include <asm/atomic.h>
  24 #include <asm/processor.h>
  25 #include <asm/system.h>
  26 #include <asm/mmu_context.h>
  27 #include <asm/smp.h>
  28 #include <asm/cacheflush.h>
  29 #include <asm/sections.h>
  30
  31 int __cpu_number_map[NR_CPUS];          /* Map physical to logical */
  32 int __cpu_logical_map[NR_CPUS];         /* Map logical to physical */
  33
  34 struct plat_smp_ops *mp_ops = NULL;
  35
  36 /* State of each CPU */
  37 DEFINE_PER_CPU(int, cpu_state) = { 0 };
  38
  39 void __cpuinit register_smp_ops(struct plat_smp_ops *ops)
  40 {
  41         if (mp_ops)
  42                 printk(KERN_WARNING "Overriding previously set SMP ops\n");
  43
  44         mp_ops = ops;
  45 }
  46
  47 static inline void __init smp_store_cpu_info(unsigned int cpu)
  48 {
  49         struct sh_cpuinfo *c = cpu_data + cpu;
  50
  51         memcpy(c, &boot_cpu_data, sizeof(struct sh_cpuinfo));
  52
  53         c->loops_per_jiffy = loops_per_jiffy;
  54 }
  55
  56 void __init smp_prepare_cpus(unsigned int max_cpus)
  57 {
  58         unsigned int cpu = smp_processor_id();
  59
  60         init_new_context(current, &init_mm);
  61         current_thread_info()->cpu = cpu;
  62         mp_ops->prepare_cpus(max_cpus);
  63
  64 #ifndef CONFIG_HOTPLUG_CPU
  65         init_cpu_present(&cpu_possible_map);
  66 #endif
  67 }
  68
  69 void __devinit smp_prepare_boot_cpu(void)
  70 {
  71         unsigned int cpu = smp_processor_id();
  72
  73         __cpu_number_map[0] = cpu;
  74         __cpu_logical_map[0] = cpu;
  75
  76         set_cpu_online(cpu, true);
  77         set_cpu_possible(cpu, true);
  78
  79         per_cpu(cpu_state, cpu) = CPU_ONLINE;
  80 }
  81
  82 asmlinkage void __cpuinit start_secondary(void)
  83 {
  84         unsigned int cpu = smp_processor_id();
  85         struct mm_struct *mm = &init_mm;
  86
  87         enable_mmu();
  88         atomic_inc(&mm->mm_count);
  89         atomic_inc(&mm->mm_users);
  90         current->active_mm = mm;
  91         BUG_ON(current->mm);
  92         enter_lazy_tlb(mm, current);
  93
  94         per_cpu_trap_init();
  95
  96         preempt_disable();
  97
  98         notify_cpu_starting(cpu);
  99
 100         local_irq_enable();
 101
 102         /* Enable local timers */
 103         local_timer_setup(cpu);
 104         calibrate_delay();
 105
 106         smp_store_cpu_info(cpu);
 107
 108         set_cpu_online(cpu, true);
 109         per_cpu(cpu_state, cpu) = CPU_ONLINE;
 110
 111         cpu_idle();
 112 }
 113
 114 extern struct {
 115         unsigned long sp;
 116         unsigned long bss_start;
 117         unsigned long bss_end;
 118         void *start_kernel_fn;
 119         void *cpu_init_fn;
 120         void *thread_info;
 121 } stack_start;
 122
 123 int __cpuinit __cpu_up(unsigned int cpu)
 124 {
 125         struct task_struct *tsk;
 126         unsigned long timeout;
 127
 128         tsk = fork_idle(cpu);
 129         if (IS_ERR(tsk)) {
 130                 printk(KERN_ERR "Failed forking idle task for cpu %d\n", cpu);
 131                 return PTR_ERR(tsk);
 132         }
 133
 134         per_cpu(cpu_state, cpu) = CPU_UP_PREPARE;
 135
 136         /* Fill in data in head.S for secondary cpus */
 137         stack_start.sp = tsk->thread.sp;
 138         stack_start.thread_info = tsk->stack;
 139         stack_start.bss_start = 0; /* don't clear bss for secondary cpus */
 140         stack_start.start_kernel_fn = start_secondary;
 141
 142         flush_icache_range((unsigned long)&stack_start,
 143                            (unsigned long)&stack_start + sizeof(stack_start));
 144         wmb();
 145
 146         mp_ops->start_cpu(cpu, (unsigned long)_stext);
 147
 148         timeout = jiffies + HZ;
 149         while (time_before(jiffies, timeout)) {
 150                 if (cpu_online(cpu))
 151                         break;
 152
 153                 udelay(10);
 154         }
 155
 156         if (cpu_online(cpu))
 157                 return 0;
 158
 159         return -ENOENT;
 160 }
 161
 162 void __init smp_cpus_done(unsigned int max_cpus)
 163 {
 164         unsigned long bogosum = 0;
 165         int cpu;
 166
 167         for_each_online_cpu(cpu)
 168                 bogosum += cpu_data[cpu].loops_per_jiffy;
 169
 170         printk(KERN_INFO "SMP: Total of %d processors activated "
 171                "(%lu.%02lu BogoMIPS).\n", num_online_cpus(),
 172                bogosum / (500000/HZ),
 173                (bogosum / (5000/HZ)) % 100);
 174 }
 175
 176 void smp_send_reschedule(int cpu)
 177 {
 178         mp_ops->send_ipi(cpu, SMP_MSG_RESCHEDULE);
 179 }
 180
 181 void smp_send_stop(void)
 182 {
 183         smp_call_function(stop_this_cpu, 0, 0);
 184 }
 185
 186 void arch_send_call_function_ipi_mask(const struct cpumask *mask)
 187 {
 188         int cpu;
 189
 190         for_each_cpu(cpu, mask)
 191                 mp_ops->send_ipi(cpu, SMP_MSG_FUNCTION);
 192 }
 193
 194 void arch_send_call_function_single_ipi(int cpu)
 195 {
 196         mp_ops->send_ipi(cpu, SMP_MSG_FUNCTION_SINGLE);
 197 }
 198
 199 void smp_timer_broadcast(const struct cpumask *mask)
 200 {
 201         int cpu;
 202
 203         for_each_cpu(cpu, mask)
 204                 mp_ops->send_ipi(cpu, SMP_MSG_TIMER);
 205 }
 206
 207 static void ipi_timer(void)
 208 {
 209         irq_enter();
 210         local_timer_interrupt();
 211         irq_exit();
 212 }
 213
 214 void smp_message_recv(unsigned int msg)
 215 {
 216         switch (msg) {
 217         case SMP_MSG_FUNCTION:
 218                 generic_smp_call_function_interrupt();
 219                 break;
 220         case SMP_MSG_RESCHEDULE:
 221                 break;
 222         case SMP_MSG_FUNCTION_SINGLE:
 223                 generic_smp_call_function_single_interrupt();
 224                 break;
 225         case SMP_MSG_TIMER:
 226                 ipi_timer();
 227                 break;
 228         default:
 229                 printk(KERN_WARNING "SMP %d: %s(): unknown IPI %d\n",
 230                        smp_processor_id(), __func__, msg);
 231                 break;
 232         }
 233 }
 234
 235 /* Not really SMP stuff ... */
 236 int setup_profiling_timer(unsigned int multiplier)
 237 {
 238         return 0;
 239 }
 240
 241 static void flush_tlb_all_ipi(void *info)
 242 {
 243         local_flush_tlb_all();
 244 }
 245
 246 void flush_tlb_all(void)
 247 {
 248         on_each_cpu(flush_tlb_all_ipi, 0, 1);
 249 }
 250
 251 static void flush_tlb_mm_ipi(void *mm)
 252 {
 253         local_flush_tlb_mm((struct mm_struct *)mm);
 254 }
 255
 256 /*
 257  * The following tlb flush calls are invoked when old translations are
 258  * being torn down, or pte attributes are changing. For single threaded
 259  * address spaces, a new context is obtained on the current cpu, and tlb
 260  * context on other cpus are invalidated to force a new context allocation
 261  * at switch_mm time, should the mm ever be used on other cpus. For
 262  * multithreaded address spaces, intercpu interrupts have to be sent.
 263  * Another case where intercpu interrupts are required is when the target
 264  * mm might be active on another cpu (eg debuggers doing the flushes on
 265  * behalf of debugees, kswapd stealing pages from another process etc).
 266  * Kanoj 07/00.
 267  */
 268
 269 void flush_tlb_mm(struct mm_struct *mm)
 270 {
 271         preempt_disable();
 272
 273         if ((atomic_read(&mm->mm_users) != 1) || (current->mm != mm)) {
 274                 smp_call_function(flush_tlb_mm_ipi, (void *)mm, 1);
 275         } else {
 276                 int i;
 277                 for (i = 0; i < num_online_cpus(); i++)
 278                         if (smp_processor_id() != i)
 279                                 cpu_context(i, mm) = 0;
 280         }
 281         local_flush_tlb_mm(mm);
 282
 283         preempt_enable();
 284 }
 285
 286 struct flush_tlb_data {
 287         struct vm_area_struct *vma;
 288         unsigned long addr1;
 289         unsigned long addr2;
 290 };
 291
 292 static void flush_tlb_range_ipi(void *info)
 293 {
 294         struct flush_tlb_data *fd = (struct flush_tlb_data *)info;
 295
 296         local_flush_tlb_range(fd->vma, fd->addr1, fd->addr2);
 297 }
 298
 299 void flush_tlb_range(struct vm_area_struct *vma,
 300                      unsigned long start, unsigned long end)
 301 {
 302         struct mm_struct *mm = vma->vm_mm;
 303
 304         preempt_disable();
 305         if ((atomic_read(&mm->mm_users) != 1) || (current->mm != mm)) {
 306                 struct flush_tlb_data fd;
 307
 308                 fd.vma = vma;
 309                 fd.addr1 = start;
 310                 fd.addr2 = end;
 311                 smp_call_function(flush_tlb_range_ipi, (void *)&fd, 1);
 312         } else {
 313                 int i;
 314                 for (i = 0; i < num_online_cpus(); i++)
 315                         if (smp_processor_id() != i)
 316                                 cpu_context(i, mm) = 0;
 317         }
 318         local_flush_tlb_range(vma, start, end);
 319         preempt_enable();
 320 }
 321
 322 static void flush_tlb_kernel_range_ipi(void *info)
 323 {
 324         struct flush_tlb_data *fd = (struct flush_tlb_data *)info;
 325
 326         local_flush_tlb_kernel_range(fd->addr1, fd->addr2);
 327 }
 328
 329 void flush_tlb_kernel_range(unsigned long start, unsigned long end)
 330 {
 331         struct flush_tlb_data fd;
 332
 333         fd.addr1 = start;
 334         fd.addr2 = end;
 335         on_each_cpu(flush_tlb_kernel_range_ipi, (void *)&fd, 1);
 336 }
 337
 338 static void flush_tlb_page_ipi(void *info)
 339 {
 340         struct flush_tlb_data *fd = (struct flush_tlb_data *)info;
 341
 342         local_flush_tlb_page(fd->vma, fd->addr1);
 343 }
 344
 345 void flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
 346 {
 347         preempt_disable();
 348         if ((atomic_read(&vma->vm_mm->mm_users) != 1) ||
 349             (current->mm != vma->vm_mm)) {
 350                 struct flush_tlb_data fd;
 351
 352                 fd.vma = vma;
 353                 fd.addr1 = page;
 354                 smp_call_function(flush_tlb_page_ipi, (void *)&fd, 1);
 355         } else {
 356                 int i;
 357                 for (i = 0; i < num_online_cpus(); i++)
 358                         if (smp_processor_id() != i)
 359                                 cpu_context(i, vma->vm_mm) = 0;
 360         }
 361         local_flush_tlb_page(vma, page);
 362         preempt_enable();
 363 }
 364
 365 static void flush_tlb_one_ipi(void *info)
 366 {
 367         struct flush_tlb_data *fd = (struct flush_tlb_data *)info;
 368         local_flush_tlb_one(fd->addr1, fd->addr2);
 369 }
 370
 371 void flush_tlb_one(unsigned long asid, unsigned long vaddr)
 372 {
 373         struct flush_tlb_data fd;
 374
 375         fd.addr1 = asid;
 376         fd.addr2 = vaddr;
 377
 378         smp_call_function(flush_tlb_one_ipi, (void *)&fd, 1);
 379         local_flush_tlb_one(asid, vaddr);
 380 }