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