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 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         calibrate_delay();
  90
  91         cpu = smp_processor_id();
  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(cpumask_t mask)
 177 {
 178         int cpu;
 179
 180         for_each_cpu_mask(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 /* Not really SMP stuff ... */
 190 int setup_profiling_timer(unsigned int multiplier)
 191 {
 192         return 0;
 193 }
 194
 195 static void flush_tlb_all_ipi(void *info)
 196 {
 197         local_flush_tlb_all();
 198 }
 199
 200 void flush_tlb_all(void)
 201 {
 202         on_each_cpu(flush_tlb_all_ipi, 0, 1);
 203 }
 204
 205 static void flush_tlb_mm_ipi(void *mm)
 206 {
 207         local_flush_tlb_mm((struct mm_struct *)mm);
 208 }
 209
 210 /*
 211  * The following tlb flush calls are invoked when old translations are
 212  * being torn down, or pte attributes are changing. For single threaded
 213  * address spaces, a new context is obtained on the current cpu, and tlb
 214  * context on other cpus are invalidated to force a new context allocation
 215  * at switch_mm time, should the mm ever be used on other cpus. For
 216  * multithreaded address spaces, intercpu interrupts have to be sent.
 217  * Another case where intercpu interrupts are required is when the target
 218  * mm might be active on another cpu (eg debuggers doing the flushes on
 219  * behalf of debugees, kswapd stealing pages from another process etc).
 220  * Kanoj 07/00.
 221  */
 222
 223 void flush_tlb_mm(struct mm_struct *mm)
 224 {
 225         preempt_disable();
 226
 227         if ((atomic_read(&mm->mm_users) != 1) || (current->mm != mm)) {
 228                 smp_call_function(flush_tlb_mm_ipi, (void *)mm, 1);
 229         } else {
 230                 int i;
 231                 for (i = 0; i < num_online_cpus(); i++)
 232                         if (smp_processor_id() != i)
 233                                 cpu_context(i, mm) = 0;
 234         }
 235         local_flush_tlb_mm(mm);
 236
 237         preempt_enable();
 238 }
 239
 240 struct flush_tlb_data {
 241         struct vm_area_struct *vma;
 242         unsigned long addr1;
 243         unsigned long addr2;
 244 };
 245
 246 static void flush_tlb_range_ipi(void *info)
 247 {
 248         struct flush_tlb_data *fd = (struct flush_tlb_data *)info;
 249
 250         local_flush_tlb_range(fd->vma, fd->addr1, fd->addr2);
 251 }
 252
 253 void flush_tlb_range(struct vm_area_struct *vma,
 254                      unsigned long start, unsigned long end)
 255 {
 256         struct mm_struct *mm = vma->vm_mm;
 257
 258         preempt_disable();
 259         if ((atomic_read(&mm->mm_users) != 1) || (current->mm != mm)) {
 260                 struct flush_tlb_data fd;
 261
 262                 fd.vma = vma;
 263                 fd.addr1 = start;
 264                 fd.addr2 = end;
 265                 smp_call_function(flush_tlb_range_ipi, (void *)&fd, 1);
 266         } else {
 267                 int i;
 268                 for (i = 0; i < num_online_cpus(); i++)
 269                         if (smp_processor_id() != i)
 270                                 cpu_context(i, mm) = 0;
 271         }
 272         local_flush_tlb_range(vma, start, end);
 273         preempt_enable();
 274 }
 275
 276 static void flush_tlb_kernel_range_ipi(void *info)
 277 {
 278         struct flush_tlb_data *fd = (struct flush_tlb_data *)info;
 279
 280         local_flush_tlb_kernel_range(fd->addr1, fd->addr2);
 281 }
 282
 283 void flush_tlb_kernel_range(unsigned long start, unsigned long end)
 284 {
 285         struct flush_tlb_data fd;
 286
 287         fd.addr1 = start;
 288         fd.addr2 = end;
 289         on_each_cpu(flush_tlb_kernel_range_ipi, (void *)&fd, 1);
 290 }
 291
 292 static void flush_tlb_page_ipi(void *info)
 293 {
 294         struct flush_tlb_data *fd = (struct flush_tlb_data *)info;
 295
 296         local_flush_tlb_page(fd->vma, fd->addr1);
 297 }
 298
 299 void flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
 300 {
 301         preempt_disable();
 302         if ((atomic_read(&vma->vm_mm->mm_users) != 1) ||
 303             (current->mm != vma->vm_mm)) {
 304                 struct flush_tlb_data fd;
 305
 306                 fd.vma = vma;
 307                 fd.addr1 = page;
 308                 smp_call_function(flush_tlb_page_ipi, (void *)&fd, 1);
 309         } else {
 310                 int i;
 311                 for (i = 0; i < num_online_cpus(); i++)
 312                         if (smp_processor_id() != i)
 313                                 cpu_context(i, vma->vm_mm) = 0;
 314         }
 315         local_flush_tlb_page(vma, page);
 316         preempt_enable();
 317 }
 318
 319 static void flush_tlb_one_ipi(void *info)
 320 {
 321         struct flush_tlb_data *fd = (struct flush_tlb_data *)info;
 322         local_flush_tlb_one(fd->addr1, fd->addr2);
 323 }
 324
 325 void flush_tlb_one(unsigned long asid, unsigned long vaddr)
 326 {
 327         struct flush_tlb_data fd;
 328
 329         fd.addr1 = asid;
 330         fd.addr2 = vaddr;
 331
 332         smp_call_function(flush_tlb_one_ipi, (void *)&fd, 1);
 333         local_flush_tlb_one(asid, vaddr);
 334 }