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