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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 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_cache_all();
 126
 127         plat_start_cpu(cpu, (unsigned long)_stext);
 128
 129         timeout = jiffies + HZ;
 130         while (time_before(jiffies, timeout)) {
 131                 if (cpu_online(cpu))
 132                         break;
 133
 134                 udelay(10);
 135         }
 136
 137         if (cpu_online(cpu))
 138                 return 0;
 139
 140         return -ENOENT;
 141 }
 142
 143 void __init smp_cpus_done(unsigned int max_cpus)
 144 {
 145         unsigned long bogosum = 0;
 146         int cpu;
 147
 148         for_each_online_cpu(cpu)
 149                 bogosum += cpu_data[cpu].loops_per_jiffy;
 150
 151         printk(KERN_INFO "SMP: Total of %d processors activated "
 152                "(%lu.%02lu BogoMIPS).\n", num_online_cpus(),
 153                bogosum / (500000/HZ),
 154                (bogosum / (5000/HZ)) % 100);
 155 }
 156
 157 void smp_send_reschedule(int cpu)
 158 {
 159         plat_send_ipi(cpu, SMP_MSG_RESCHEDULE);
 160 }
 161
 162 static void stop_this_cpu(void *unused)
 163 {
 164         cpu_clear(smp_processor_id(), cpu_online_map);
 165         local_irq_disable();
 166
 167         for (;;)
 168                 cpu_relax();
 169 }
 170
 171 void smp_send_stop(void)
 172 {
 173         smp_call_function(stop_this_cpu, 0, 0);
 174 }
 175
 176 void arch_send_call_function_ipi_mask(const struct cpumask *mask)
 177 {
 178         int cpu;
 179
 180         for_each_cpu(cpu, mask)
 181                 plat_send_ipi(cpu, SMP_MSG_FUNCTION);
 182 }
 183
 184 void arch_send_call_function_single_ipi(int cpu)
 185 {
 186         plat_send_ipi(cpu, SMP_MSG_FUNCTION_SINGLE);
 187 }
 188
 189 void smp_timer_broadcast(const struct cpumask *mask)
 190 {
 191         int cpu;
 192
 193         for_each_cpu(cpu, mask)
 194                 plat_send_ipi(cpu, SMP_MSG_TIMER);
 195 }
 196
 197 static void ipi_timer(void)
 198 {
 199         irq_enter();
 200         local_timer_interrupt();
 201         irq_exit();
 202 }
 203
 204 void smp_message_recv(unsigned int msg)
 205 {
 206         switch (msg) {
 207         case SMP_MSG_FUNCTION:
 208                 generic_smp_call_function_interrupt();
 209                 break;
 210         case SMP_MSG_RESCHEDULE:
 211                 break;
 212         case SMP_MSG_FUNCTION_SINGLE:
 213                 generic_smp_call_function_single_interrupt();
 214                 break;
 215         case SMP_MSG_TIMER:
 216                 ipi_timer();
 217                 break;
 218         default:
 219                 printk(KERN_WARNING "SMP %d: %s(): unknown IPI %d\n",
 220                        smp_processor_id(), __func__, msg);
 221                 break;
 222         }
 223 }
 224
 225 /* Not really SMP stuff ... */
 226 int setup_profiling_timer(unsigned int multiplier)
 227 {
 228         return 0;
 229 }
 230
 231 static void flush_tlb_all_ipi(void *info)
 232 {
 233         local_flush_tlb_all();
 234 }
 235
 236 void flush_tlb_all(void)
 237 {
 238         on_each_cpu(flush_tlb_all_ipi, 0, 1);
 239 }
 240
 241 static void flush_tlb_mm_ipi(void *mm)
 242 {
 243         local_flush_tlb_mm((struct mm_struct *)mm);
 244 }
 245
 246 /*
 247  * The following tlb flush calls are invoked when old translations are
 248  * being torn down, or pte attributes are changing. For single threaded
 249  * address spaces, a new context is obtained on the current cpu, and tlb
 250  * context on other cpus are invalidated to force a new context allocation
 251  * at switch_mm time, should the mm ever be used on other cpus. For
 252  * multithreaded address spaces, intercpu interrupts have to be sent.
 253  * Another case where intercpu interrupts are required is when the target
 254  * mm might be active on another cpu (eg debuggers doing the flushes on
 255  * behalf of debugees, kswapd stealing pages from another process etc).
 256  * Kanoj 07/00.
 257  */
 258
 259 void flush_tlb_mm(struct mm_struct *mm)
 260 {
 261         preempt_disable();
 262
 263         if ((atomic_read(&mm->mm_users) != 1) || (current->mm != mm)) {
 264                 smp_call_function(flush_tlb_mm_ipi, (void *)mm, 1);
 265         } else {
 266                 int i;
 267                 for (i = 0; i < num_online_cpus(); i++)
 268                         if (smp_processor_id() != i)
 269                                 cpu_context(i, mm) = 0;
 270         }
 271         local_flush_tlb_mm(mm);
 272
 273         preempt_enable();
 274 }
 275
 276 struct flush_tlb_data {
 277         struct vm_area_struct *vma;
 278         unsigned long addr1;
 279         unsigned long addr2;
 280 };
 281
 282 static void flush_tlb_range_ipi(void *info)
 283 {
 284         struct flush_tlb_data *fd = (struct flush_tlb_data *)info;
 285
 286         local_flush_tlb_range(fd->vma, fd->addr1, fd->addr2);
 287 }
 288
 289 void flush_tlb_range(struct vm_area_struct *vma,
 290                      unsigned long start, unsigned long end)
 291 {
 292         struct mm_struct *mm = vma->vm_mm;
 293
 294         preempt_disable();
 295         if ((atomic_read(&mm->mm_users) != 1) || (current->mm != mm)) {
 296                 struct flush_tlb_data fd;
 297
 298                 fd.vma = vma;
 299                 fd.addr1 = start;
 300                 fd.addr2 = end;
 301                 smp_call_function(flush_tlb_range_ipi, (void *)&fd, 1);
 302         } else {
 303                 int i;
 304                 for (i = 0; i < num_online_cpus(); i++)
 305                         if (smp_processor_id() != i)
 306                                 cpu_context(i, mm) = 0;
 307         }
 308         local_flush_tlb_range(vma, start, end);
 309         preempt_enable();
 310 }
 311
 312 static void flush_tlb_kernel_range_ipi(void *info)
 313 {
 314         struct flush_tlb_data *fd = (struct flush_tlb_data *)info;
 315
 316         local_flush_tlb_kernel_range(fd->addr1, fd->addr2);
 317 }
 318
 319 void flush_tlb_kernel_range(unsigned long start, unsigned long end)
 320 {
 321         struct flush_tlb_data fd;
 322
 323         fd.addr1 = start;
 324         fd.addr2 = end;
 325         on_each_cpu(flush_tlb_kernel_range_ipi, (void *)&fd, 1);
 326 }
 327
 328 static void flush_tlb_page_ipi(void *info)
 329 {
 330         struct flush_tlb_data *fd = (struct flush_tlb_data *)info;
 331
 332         local_flush_tlb_page(fd->vma, fd->addr1);
 333 }
 334
 335 void flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
 336 {
 337         preempt_disable();
 338         if ((atomic_read(&vma->vm_mm->mm_users) != 1) ||
 339             (current->mm != vma->vm_mm)) {
 340                 struct flush_tlb_data fd;
 341
 342                 fd.vma = vma;
 343                 fd.addr1 = page;
 344                 smp_call_function(flush_tlb_page_ipi, (void *)&fd, 1);
 345         } else {
 346                 int i;
 347                 for (i = 0; i < num_online_cpus(); i++)
 348                         if (smp_processor_id() != i)
 349                                 cpu_context(i, vma->vm_mm) = 0;
 350         }
 351         local_flush_tlb_page(vma, page);
 352         preempt_enable();
 353 }
 354
 355 static void flush_tlb_one_ipi(void *info)
 356 {
 357         struct flush_tlb_data *fd = (struct flush_tlb_data *)info;
 358         local_flush_tlb_one(fd->addr1, fd->addr2);
 359 }
 360
 361 void flush_tlb_one(unsigned long asid, unsigned long vaddr)
 362 {
 363         struct flush_tlb_data fd;
 364
 365         fd.addr1 = asid;
 366         fd.addr2 = vaddr;
 367
 368         smp_call_function(flush_tlb_one_ipi, (void *)&fd, 1);
 369         local_flush_tlb_one(asid, vaddr);
 370 }