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 - 2008 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 static inline void __init smp_store_cpu_info(unsigned int cpu)
  35 {
  36         struct sh_cpuinfo *c = cpu_data + cpu;
  37
  38         memcpy(c, &boot_cpu_data, sizeof(struct sh_cpuinfo));
  39
  40         c->loops_per_jiffy = loops_per_jiffy;
  41 }
  42
  43 void __init smp_prepare_cpus(unsigned int max_cpus)
  44 {
  45         unsigned int cpu = smp_processor_id();
  46
  47         init_new_context(current, &init_mm);
  48         current_thread_info()->cpu = cpu;
  49         plat_prepare_cpus(max_cpus);
  50
  51 #ifndef CONFIG_HOTPLUG_CPU
  52         init_cpu_present(&cpu_possible_map);
  53 #endif
  54 }
  55
  56 void __devinit smp_prepare_boot_cpu(void)
  57 {
  58         unsigned int cpu = smp_processor_id();
  59
  60         __cpu_number_map[0] = cpu;
  61         __cpu_logical_map[0] = cpu;
  62
  63         set_cpu_online(cpu, true);
  64         set_cpu_possible(cpu, true);
  65 }
  66
  67 asmlinkage void __cpuinit start_secondary(void)
  68 {
  69         unsigned int cpu;
  70         struct mm_struct *mm = &init_mm;
  71
  72         atomic_inc(&mm->mm_count);
  73         atomic_inc(&mm->mm_users);
  74         current->active_mm = mm;
  75         BUG_ON(current->mm);
  76         enter_lazy_tlb(mm, current);
  77
  78         per_cpu_trap_init();
  79
  80         preempt_disable();
  81
  82         notify_cpu_starting(smp_processor_id());
  83
  84         local_irq_enable();
  85
  86         cpu = smp_processor_id();
  87
  88         /* Enable local timers */
  89         local_timer_setup(cpu);
  90         calibrate_delay();
  91
  92         smp_store_cpu_info(cpu);
  93
  94         cpu_set(cpu, cpu_online_map);
  95
  96         cpu_idle();
  97 }
  98
  99 extern struct {
 100         unsigned long sp;
 101         unsigned long bss_start;
 102         unsigned long bss_end;
 103         void *start_kernel_fn;
 104         void *cpu_init_fn;
 105         void *thread_info;
 106 } stack_start;
 107
 108 int __cpuinit __cpu_up(unsigned int cpu)
 109 {
 110         struct task_struct *tsk;
 111         unsigned long timeout;
 112
 113         tsk = fork_idle(cpu);
 114         if (IS_ERR(tsk)) {
 115                 printk(KERN_ERR "Failed forking idle task for cpu %d\n", cpu);
 116                 return PTR_ERR(tsk);
 117         }
 118
 119         /* Fill in data in head.S for secondary cpus */
 120         stack_start.sp = tsk->thread.sp;
 121         stack_start.thread_info = tsk->stack;
 122         stack_start.bss_start = 0; /* don't clear bss for secondary cpus */
 123         stack_start.start_kernel_fn = start_secondary;
 124
 125         flush_icache_range((unsigned long)&stack_start,
 126                            (unsigned long)&stack_start + sizeof(stack_start));
 127         wmb();
 128
 129         plat_start_cpu(cpu, (unsigned long)_stext);
 130
 131         timeout = jiffies + HZ;
 132         while (time_before(jiffies, timeout)) {
 133                 if (cpu_online(cpu))
 134                         break;
 135
 136                 udelay(10);
 137         }
 138
 139         if (cpu_online(cpu))
 140                 return 0;
 141
 142         return -ENOENT;
 143 }
 144
 145 void __init smp_cpus_done(unsigned int max_cpus)
 146 {
 147         unsigned long bogosum = 0;
 148         int cpu;
 149
 150         for_each_online_cpu(cpu)
 151                 bogosum += cpu_data[cpu].loops_per_jiffy;
 152
 153         printk(KERN_INFO "SMP: Total of %d processors activated "
 154                "(%lu.%02lu BogoMIPS).\n", num_online_cpus(),
 155                bogosum / (500000/HZ),
 156                (bogosum / (5000/HZ)) % 100);
 157 }
 158
 159 void smp_send_reschedule(int cpu)
 160 {
 161         plat_send_ipi(cpu, SMP_MSG_RESCHEDULE);
 162 }
 163
 164 static void stop_this_cpu(void *unused)
 165 {
 166         cpu_clear(smp_processor_id(), cpu_online_map);
 167         local_irq_disable();
 168
 169         for (;;)
 170                 cpu_relax();
 171 }
 172
 173 void smp_send_stop(void)
 174 {
 175         smp_call_function(stop_this_cpu, 0, 0);
 176 }
 177
 178 void arch_send_call_function_ipi_mask(const struct cpumask *mask)
 179 {
 180         int cpu;
 181
 182         for_each_cpu(cpu, mask)
 183                 plat_send_ipi(cpu, SMP_MSG_FUNCTION);
 184 }
 185
 186 void arch_send_call_function_single_ipi(int cpu)
 187 {
 188         plat_send_ipi(cpu, SMP_MSG_FUNCTION_SINGLE);
 189 }
 190
 191 void smp_timer_broadcast(const struct cpumask *mask)
 192 {
 193         int cpu;
 194
 195         for_each_cpu(cpu, mask)
 196                 plat_send_ipi(cpu, SMP_MSG_TIMER);
 197 }
 198
 199 static void ipi_timer(void)
 200 {
 201         irq_enter();
 202         local_timer_interrupt();
 203         irq_exit();
 204 }
 205
 206 void smp_message_recv(unsigned int msg)
 207 {
 208         switch (msg) {
 209         case SMP_MSG_FUNCTION:
 210                 generic_smp_call_function_interrupt();
 211                 break;
 212         case SMP_MSG_RESCHEDULE:
 213                 break;
 214         case SMP_MSG_FUNCTION_SINGLE:
 215                 generic_smp_call_function_single_interrupt();
 216                 break;
 217         case SMP_MSG_TIMER:
 218                 ipi_timer();
 219                 break;
 220         default:
 221                 printk(KERN_WARNING "SMP %d: %s(): unknown IPI %d\n",
 222                        smp_processor_id(), __func__, msg);
 223                 break;
 224         }
 225 }
 226
 227 /* Not really SMP stuff ... */
 228 int setup_profiling_timer(unsigned int multiplier)
 229 {
 230         return 0;
 231 }
 232
 233 static void flush_tlb_all_ipi(void *info)
 234 {
 235         local_flush_tlb_all();
 236 }
 237
 238 void flush_tlb_all(void)
 239 {
 240         on_each_cpu(flush_tlb_all_ipi, 0, 1);
 241 }
 242
 243 static void flush_tlb_mm_ipi(void *mm)
 244 {
 245         local_flush_tlb_mm((struct mm_struct *)mm);
 246 }
 247
 248 /*
 249  * The following tlb flush calls are invoked when old translations are
 250  * being torn down, or pte attributes are changing. For single threaded
 251  * address spaces, a new context is obtained on the current cpu, and tlb
 252  * context on other cpus are invalidated to force a new context allocation
 253  * at switch_mm time, should the mm ever be used on other cpus. For
 254  * multithreaded address spaces, intercpu interrupts have to be sent.
 255  * Another case where intercpu interrupts are required is when the target
 256  * mm might be active on another cpu (eg debuggers doing the flushes on
 257  * behalf of debugees, kswapd stealing pages from another process etc).
 258  * Kanoj 07/00.
 259  */
 260
 261 void flush_tlb_mm(struct mm_struct *mm)
 262 {
 263         preempt_disable();
 264
 265         if ((atomic_read(&mm->mm_users) != 1) || (current->mm != mm)) {
 266                 smp_call_function(flush_tlb_mm_ipi, (void *)mm, 1);
 267         } else {
 268                 int i;
 269                 for (i = 0; i < num_online_cpus(); i++)
 270                         if (smp_processor_id() != i)
 271                                 cpu_context(i, mm) = 0;
 272         }
 273         local_flush_tlb_mm(mm);
 274
 275         preempt_enable();
 276 }
 277
 278 struct flush_tlb_data {
 279         struct vm_area_struct *vma;
 280         unsigned long addr1;
 281         unsigned long addr2;
 282 };
 283
 284 static void flush_tlb_range_ipi(void *info)
 285 {
 286         struct flush_tlb_data *fd = (struct flush_tlb_data *)info;
 287
 288         local_flush_tlb_range(fd->vma, fd->addr1, fd->addr2);
 289 }
 290
 291 void flush_tlb_range(struct vm_area_struct *vma,
 292                      unsigned long start, unsigned long end)
 293 {
 294         struct mm_struct *mm = vma->vm_mm;
 295
 296         preempt_disable();
 297         if ((atomic_read(&mm->mm_users) != 1) || (current->mm != mm)) {
 298                 struct flush_tlb_data fd;
 299
 300                 fd.vma = vma;
 301                 fd.addr1 = start;
 302                 fd.addr2 = end;
 303                 smp_call_function(flush_tlb_range_ipi, (void *)&fd, 1);
 304         } else {
 305                 int i;
 306                 for (i = 0; i < num_online_cpus(); i++)
 307                         if (smp_processor_id() != i)
 308                                 cpu_context(i, mm) = 0;
 309         }
 310         local_flush_tlb_range(vma, start, end);
 311         preempt_enable();
 312 }
 313
 314 static void flush_tlb_kernel_range_ipi(void *info)
 315 {
 316         struct flush_tlb_data *fd = (struct flush_tlb_data *)info;
 317
 318         local_flush_tlb_kernel_range(fd->addr1, fd->addr2);
 319 }
 320
 321 void flush_tlb_kernel_range(unsigned long start, unsigned long end)
 322 {
 323         struct flush_tlb_data fd;
 324
 325         fd.addr1 = start;
 326         fd.addr2 = end;
 327         on_each_cpu(flush_tlb_kernel_range_ipi, (void *)&fd, 1);
 328 }
 329
 330 static void flush_tlb_page_ipi(void *info)
 331 {
 332         struct flush_tlb_data *fd = (struct flush_tlb_data *)info;
 333
 334         local_flush_tlb_page(fd->vma, fd->addr1);
 335 }
 336
 337 void flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
 338 {
 339         preempt_disable();
 340         if ((atomic_read(&vma->vm_mm->mm_users) != 1) ||
 341             (current->mm != vma->vm_mm)) {
 342                 struct flush_tlb_data fd;
 343
 344                 fd.vma = vma;
 345                 fd.addr1 = page;
 346                 smp_call_function(flush_tlb_page_ipi, (void *)&fd, 1);
 347         } else {
 348                 int i;
 349                 for (i = 0; i < num_online_cpus(); i++)
 350                         if (smp_processor_id() != i)
 351                                 cpu_context(i, vma->vm_mm) = 0;
 352         }
 353         local_flush_tlb_page(vma, page);
 354         preempt_enable();
 355 }
 356
 357 static void flush_tlb_one_ipi(void *info)
 358 {
 359         struct flush_tlb_data *fd = (struct flush_tlb_data *)info;
 360         local_flush_tlb_one(fd->addr1, fd->addr2);
 361 }
 362
 363 void flush_tlb_one(unsigned long asid, unsigned long vaddr)
 364 {
 365         struct flush_tlb_data fd;
 366
 367         fd.addr1 = asid;
 368         fd.addr2 = vaddr;
 369
 370         smp_call_function(flush_tlb_one_ipi, (void *)&fd, 1);
 371         local_flush_tlb_one(asid, vaddr);
 372 }