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