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 - 2007 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/interrupt.h>
  22 #include <asm/atomic.h>
  23 #include <asm/processor.h>
  24 #include <asm/system.h>
  25 #include <asm/mmu_context.h>
  26 #include <asm/smp.h>
  27 #include <asm/cacheflush.h>
  28 #include <asm/sections.h>
  29
  30 int __cpu_number_map[NR_CPUS];          /* Map physical to logical */
  31 int __cpu_logical_map[NR_CPUS];         /* Map logical to physical */
  32
  33 cpumask_t cpu_possible_map;
  34 EXPORT_SYMBOL(cpu_possible_map);
  35
  36 cpumask_t cpu_online_map;
  37 EXPORT_SYMBOL(cpu_online_map);
  38
  39 static atomic_t cpus_booted = ATOMIC_INIT(0);
  40
  41 /*
  42  * Run specified function on a particular processor.
  43  */
  44 void __smp_call_function(unsigned int cpu);
  45
  46 static inline void __init smp_store_cpu_info(unsigned int cpu)
  47 {
  48         struct sh_cpuinfo *c = cpu_data + cpu;
  49
  50         c->loops_per_jiffy = loops_per_jiffy;
  51 }
  52
  53 void __init smp_prepare_cpus(unsigned int max_cpus)
  54 {
  55         unsigned int cpu = smp_processor_id();
  56
  57         init_new_context(current, &init_mm);
  58         current_thread_info()->cpu = cpu;
  59         plat_prepare_cpus(max_cpus);
  60
  61 #ifndef CONFIG_HOTPLUG_CPU
  62         cpu_present_map = cpu_possible_map;
  63 #endif
  64 }
  65
  66 void __devinit smp_prepare_boot_cpu(void)
  67 {
  68         unsigned int cpu = smp_processor_id();
  69
  70         __cpu_number_map[0] = cpu;
  71         __cpu_logical_map[0] = cpu;
  72
  73         cpu_set(cpu, cpu_online_map);
  74         cpu_set(cpu, cpu_possible_map);
  75 }
  76
  77 asmlinkage void __cpuinit start_secondary(void)
  78 {
  79         unsigned int cpu;
  80         struct mm_struct *mm = &init_mm;
  81
  82         atomic_inc(&mm->mm_count);
  83         atomic_inc(&mm->mm_users);
  84         current->active_mm = mm;
  85         BUG_ON(current->mm);
  86         enter_lazy_tlb(mm, current);
  87
  88         per_cpu_trap_init();
  89
  90         preempt_disable();
  91
  92         local_irq_enable();
  93
  94         calibrate_delay();
  95
  96         cpu = smp_processor_id();
  97         smp_store_cpu_info(cpu);
  98
  99         cpu_set(cpu, cpu_online_map);
 100
 101         cpu_idle();
 102 }
 103
 104 extern struct {
 105         unsigned long sp;
 106         unsigned long bss_start;
 107         unsigned long bss_end;
 108         void *start_kernel_fn;
 109         void *cpu_init_fn;
 110         void *thread_info;
 111 } stack_start;
 112
 113 int __cpuinit __cpu_up(unsigned int cpu)
 114 {
 115         struct task_struct *tsk;
 116         unsigned long timeout;
 117
 118         tsk = fork_idle(cpu);
 119         if (IS_ERR(tsk)) {
 120                 printk(KERN_ERR "Failed forking idle task for cpu %d\n", cpu);
 121                 return PTR_ERR(tsk);
 122         }
 123
 124         /* Fill in data in head.S for secondary cpus */
 125         stack_start.sp = tsk->thread.sp;
 126         stack_start.thread_info = tsk->stack;
 127         stack_start.bss_start = 0; /* don't clear bss for secondary cpus */
 128         stack_start.start_kernel_fn = start_secondary;
 129
 130         flush_cache_all();
 131
 132         plat_start_cpu(cpu, (unsigned long)_stext);
 133
 134         timeout = jiffies + HZ;
 135         while (time_before(jiffies, timeout)) {
 136                 if (cpu_online(cpu))
 137                         break;
 138
 139                 udelay(10);
 140         }
 141
 142         if (cpu_online(cpu))
 143                 return 0;
 144
 145         return -ENOENT;
 146 }
 147
 148 void __init smp_cpus_done(unsigned int max_cpus)
 149 {
 150         unsigned long bogosum = 0;
 151         int cpu;
 152
 153         for_each_online_cpu(cpu)
 154                 bogosum += cpu_data[cpu].loops_per_jiffy;
 155
 156         printk(KERN_INFO "SMP: Total of %d processors activated "
 157                "(%lu.%02lu BogoMIPS).\n", num_online_cpus(),
 158                bogosum / (500000/HZ),
 159                (bogosum / (5000/HZ)) % 100);
 160 }
 161
 162 void smp_send_reschedule(int cpu)
 163 {
 164         plat_send_ipi(cpu, SMP_MSG_RESCHEDULE);
 165 }
 166
 167 static void stop_this_cpu(void *unused)
 168 {
 169         cpu_clear(smp_processor_id(), cpu_online_map);
 170         local_irq_disable();
 171
 172         for (;;)
 173                 cpu_relax();
 174 }
 175
 176 void smp_send_stop(void)
 177 {
 178         smp_call_function(stop_this_cpu, 0, 1, 0);
 179 }
 180
 181 struct smp_fn_call_struct smp_fn_call = {
 182         .lock           = __SPIN_LOCK_UNLOCKED(smp_fn_call.lock),
 183         .finished       = ATOMIC_INIT(0),
 184 };
 185
 186 /*
 187  * The caller of this wants the passed function to run on every cpu.  If wait
 188  * is set, wait until all cpus have finished the function before returning.
 189  * The lock is here to protect the call structure.
 190  * You must not call this function with disabled interrupts or from a
 191  * hardware interrupt handler or from a bottom half handler.
 192  */
 193 int smp_call_function(void (*func)(void *info), void *info, int retry, int wait)
 194 {
 195         unsigned int nr_cpus = atomic_read(&cpus_booted);
 196         int i;
 197
 198         /* Can deadlock when called with interrupts disabled */
 199         WARN_ON(irqs_disabled());
 200
 201         spin_lock(&smp_fn_call.lock);
 202
 203         atomic_set(&smp_fn_call.finished, 0);
 204         smp_fn_call.fn = func;
 205         smp_fn_call.data = info;
 206
 207         for (i = 0; i < nr_cpus; i++)
 208                 if (i != smp_processor_id())
 209                         plat_send_ipi(i, SMP_MSG_FUNCTION);
 210
 211         if (wait)
 212                 while (atomic_read(&smp_fn_call.finished) != (nr_cpus - 1));
 213
 214         spin_unlock(&smp_fn_call.lock);
 215
 216         return 0;
 217 }
 218
 219 /* Not really SMP stuff ... */
 220 int setup_profiling_timer(unsigned int multiplier)
 221 {
 222         return 0;
 223 }
 224
 225 static void flush_tlb_all_ipi(void *info)
 226 {
 227         local_flush_tlb_all();
 228 }
 229
 230 void flush_tlb_all(void)
 231 {
 232         on_each_cpu(flush_tlb_all_ipi, 0, 1, 1);
 233 }
 234
 235 static void flush_tlb_mm_ipi(void *mm)
 236 {
 237         local_flush_tlb_mm((struct mm_struct *)mm);
 238 }
 239
 240 /*
 241  * The following tlb flush calls are invoked when old translations are
 242  * being torn down, or pte attributes are changing. For single threaded
 243  * address spaces, a new context is obtained on the current cpu, and tlb
 244  * context on other cpus are invalidated to force a new context allocation
 245  * at switch_mm time, should the mm ever be used on other cpus. For
 246  * multithreaded address spaces, intercpu interrupts have to be sent.
 247  * Another case where intercpu interrupts are required is when the target
 248  * mm might be active on another cpu (eg debuggers doing the flushes on
 249  * behalf of debugees, kswapd stealing pages from another process etc).
 250  * Kanoj 07/00.
 251  */
 252
 253 void flush_tlb_mm(struct mm_struct *mm)
 254 {
 255         preempt_disable();
 256
 257         if ((atomic_read(&mm->mm_users) != 1) || (current->mm != mm)) {
 258                 smp_call_function(flush_tlb_mm_ipi, (void *)mm, 1, 1);
 259         } else {
 260                 int i;
 261                 for (i = 0; i < num_online_cpus(); i++)
 262                         if (smp_processor_id() != i)
 263                                 cpu_context(i, mm) = 0;
 264         }
 265         local_flush_tlb_mm(mm);
 266
 267         preempt_enable();
 268 }
 269
 270 struct flush_tlb_data {
 271         struct vm_area_struct *vma;
 272         unsigned long addr1;
 273         unsigned long addr2;
 274 };
 275
 276 static void flush_tlb_range_ipi(void *info)
 277 {
 278         struct flush_tlb_data *fd = (struct flush_tlb_data *)info;
 279
 280         local_flush_tlb_range(fd->vma, fd->addr1, fd->addr2);
 281 }
 282
 283 void flush_tlb_range(struct vm_area_struct *vma,
 284                      unsigned long start, unsigned long end)
 285 {
 286         struct mm_struct *mm = vma->vm_mm;
 287
 288         preempt_disable();
 289         if ((atomic_read(&mm->mm_users) != 1) || (current->mm != mm)) {
 290                 struct flush_tlb_data fd;
 291
 292                 fd.vma = vma;
 293                 fd.addr1 = start;
 294                 fd.addr2 = end;
 295                 smp_call_function(flush_tlb_range_ipi, (void *)&fd, 1, 1);
 296         } else {
 297                 int i;
 298                 for (i = 0; i < num_online_cpus(); i++)
 299                         if (smp_processor_id() != i)
 300                                 cpu_context(i, mm) = 0;
 301         }
 302         local_flush_tlb_range(vma, start, end);
 303         preempt_enable();
 304 }
 305
 306 static void flush_tlb_kernel_range_ipi(void *info)
 307 {
 308         struct flush_tlb_data *fd = (struct flush_tlb_data *)info;
 309
 310         local_flush_tlb_kernel_range(fd->addr1, fd->addr2);
 311 }
 312
 313 void flush_tlb_kernel_range(unsigned long start, unsigned long end)
 314 {
 315         struct flush_tlb_data fd;
 316
 317         fd.addr1 = start;
 318         fd.addr2 = end;
 319         on_each_cpu(flush_tlb_kernel_range_ipi, (void *)&fd, 1, 1);
 320 }
 321
 322 static void flush_tlb_page_ipi(void *info)
 323 {
 324         struct flush_tlb_data *fd = (struct flush_tlb_data *)info;
 325
 326         local_flush_tlb_page(fd->vma, fd->addr1);
 327 }
 328
 329 void flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
 330 {
 331         preempt_disable();
 332         if ((atomic_read(&vma->vm_mm->mm_users) != 1) ||
 333             (current->mm != vma->vm_mm)) {
 334                 struct flush_tlb_data fd;
 335
 336                 fd.vma = vma;
 337                 fd.addr1 = page;
 338                 smp_call_function(flush_tlb_page_ipi, (void *)&fd, 1, 1);
 339         } else {
 340                 int i;
 341                 for (i = 0; i < num_online_cpus(); i++)
 342                         if (smp_processor_id() != i)
 343                                 cpu_context(i, vma->vm_mm) = 0;
 344         }
 345         local_flush_tlb_page(vma, page);
 346         preempt_enable();
 347 }
 348
 349 static void flush_tlb_one_ipi(void *info)
 350 {
 351         struct flush_tlb_data *fd = (struct flush_tlb_data *)info;
 352         local_flush_tlb_one(fd->addr1, fd->addr2);
 353 }
 354
 355 void flush_tlb_one(unsigned long asid, unsigned long vaddr)
 356 {
 357         struct flush_tlb_data fd;
 358
 359         fd.addr1 = asid;
 360         fd.addr2 = vaddr;
 361
 362         smp_call_function(flush_tlb_one_ipi, (void *)&fd, 1, 1);
 363         local_flush_tlb_one(asid, vaddr);
 364 }