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