arch/cris/arch-v32/kernel/smp.c

   1 #include <linux/types.h>
   2 #include <asm/delay.h>
   3 #include <irq.h>
   4 #include <hwregs/intr_vect.h>
   5 #include <hwregs/intr_vect_defs.h>
   6 #include <asm/tlbflush.h>
   7 #include <asm/mmu_context.h>
   8 #include <hwregs/asm/mmu_defs_asm.h>
   9 #include <hwregs/supp_reg.h>
  10 #include <asm/atomic.h>
  11
  12 #include <linux/err.h>
  13 #include <linux/init.h>
  14 #include <linux/timex.h>
  15 #include <linux/sched.h>
  16 #include <linux/kernel.h>
  17 #include <linux/cpumask.h>
  18 #include <linux/interrupt.h>
  19 #include <linux/module.h>
  20
  21 #define IPI_SCHEDULE 1
  22 #define IPI_CALL 2
  23 #define IPI_FLUSH_TLB 4
  24 #define IPI_BOOT 8
  25
  26 #define FLUSH_ALL (void*)0xffffffff
  27
  28 /* Vector of locks used for various atomic operations */
  29 spinlock_t cris_atomic_locks[] = { [0 ... LOCK_COUNT - 1] = SPIN_LOCK_UNLOCKED};
  30
  31 /* CPU masks */
  32 cpumask_t phys_cpu_present_map = CPU_MASK_NONE;
  33 EXPORT_SYMBOL(phys_cpu_present_map);
  34
  35 /* Variables used during SMP boot */
  36 volatile int cpu_now_booting = 0;
  37 volatile struct thread_info *smp_init_current_idle_thread;
  38
  39 /* Variables used during IPI */
  40 static DEFINE_SPINLOCK(call_lock);
  41 static DEFINE_SPINLOCK(tlbstate_lock);
  42
  43 struct call_data_struct {
  44         void (*func) (void *info);
  45         void *info;
  46         int wait;
  47 };
  48
  49 static struct call_data_struct * call_data;
  50
  51 static struct mm_struct* flush_mm;
  52 static struct vm_area_struct* flush_vma;
  53 static unsigned long flush_addr;
  54
  55 /* Mode registers */
  56 static unsigned long irq_regs[NR_CPUS] = {
  57   regi_irq,
  58   regi_irq2
  59 };
  60
  61 static irqreturn_t crisv32_ipi_interrupt(int irq, void *dev_id);
  62 static int send_ipi(int vector, int wait, cpumask_t cpu_mask);
  63 static struct irqaction irq_ipi  = {
  64         .handler = crisv32_ipi_interrupt,
  65         .flags = IRQF_DISABLED,
  66         .name = "ipi",
  67 };
  68
  69 extern void cris_mmu_init(void);
  70 extern void cris_timer_init(void);
  71
  72 /* SMP initialization */
  73 void __init smp_prepare_cpus(unsigned int max_cpus)
  74 {
  75         int i;
  76
  77         /* From now on we can expect IPIs so set them up */
  78         setup_irq(IPI_INTR_VECT, &irq_ipi);
  79
  80         /* Mark all possible CPUs as present */
  81         for (i = 0; i < max_cpus; i++)
  82             cpu_set(i, phys_cpu_present_map);
  83 }
  84
  85 void __devinit smp_prepare_boot_cpu(void)
  86 {
  87         /* PGD pointer has moved after per_cpu initialization so
  88          * update the MMU.
  89          */
  90         pgd_t **pgd;
  91         pgd = (pgd_t**)&per_cpu(current_pgd, smp_processor_id());
  92
  93         SUPP_BANK_SEL(1);
  94         SUPP_REG_WR(RW_MM_TLB_PGD, pgd);
  95         SUPP_BANK_SEL(2);
  96         SUPP_REG_WR(RW_MM_TLB_PGD, pgd);
  97
  98         set_cpu_online(0, true);
  99         cpu_set(0, phys_cpu_present_map);
 100         set_cpu_possible(0, true);
 101 }
 102
 103 void __init smp_cpus_done(unsigned int max_cpus)
 104 {
 105 }
 106
 107 /* Bring one cpu online.*/
 108 static int __init
 109 smp_boot_one_cpu(int cpuid)
 110 {
 111         unsigned timeout;
 112         struct task_struct *idle;
 113         cpumask_t cpu_mask = CPU_MASK_NONE;
 114
 115         idle = fork_idle(cpuid);
 116         if (IS_ERR(idle))
 117                 panic("SMP: fork failed for CPU:%d", cpuid);
 118
 119         task_thread_info(idle)->cpu = cpuid;
 120
 121         /* Information to the CPU that is about to boot */
 122         smp_init_current_idle_thread = task_thread_info(idle);
 123         cpu_now_booting = cpuid;
 124
 125         /* Kick it */
 126         cpu_set(cpuid, cpu_online_map);
 127         cpu_set(cpuid, cpu_mask);
 128         send_ipi(IPI_BOOT, 0, cpu_mask);
 129         cpu_clear(cpuid, cpu_online_map);
 130
 131         /* Wait for CPU to come online */
 132         for (timeout = 0; timeout < 10000; timeout++) {
 133                 if(cpu_online(cpuid)) {
 134                         cpu_now_booting = 0;
 135                         smp_init_current_idle_thread = NULL;
 136                         return 0; /* CPU online */
 137                 }
 138                 udelay(100);
 139                 barrier();
 140         }
 141
 142         put_task_struct(idle);
 143         idle = NULL;
 144
 145         printk(KERN_CRIT "SMP: CPU:%d is stuck.\n", cpuid);
 146         return -1;
 147 }
 148
 149 /* Secondary CPUs starts using C here. Here we need to setup CPU
 150  * specific stuff such as the local timer and the MMU. */
 151 void __init smp_callin(void)
 152 {
 153         extern void cpu_idle(void);
 154
 155         int cpu = cpu_now_booting;
 156         reg_intr_vect_rw_mask vect_mask = {0};
 157
 158         /* Initialise the idle task for this CPU */
 159         atomic_inc(&init_mm.mm_count);
 160         current->active_mm = &init_mm;
 161
 162         /* Set up MMU */
 163         cris_mmu_init();
 164         __flush_tlb_all();
 165
 166         /* Setup local timer. */
 167         cris_timer_init();
 168
 169         /* Enable IRQ and idle */
 170         REG_WR(intr_vect, irq_regs[cpu], rw_mask, vect_mask);
 171         unmask_irq(IPI_INTR_VECT);
 172         unmask_irq(TIMER0_INTR_VECT);
 173         preempt_disable();
 174         notify_cpu_starting(cpu);
 175         local_irq_enable();
 176
 177         cpu_set(cpu, cpu_online_map);
 178         cpu_idle();
 179 }
 180
 181 /* Stop execution on this CPU.*/
 182 void stop_this_cpu(void* dummy)
 183 {
 184         local_irq_disable();
 185         asm volatile("halt");
 186 }
 187
 188 /* Other calls */
 189 void smp_send_stop(void)
 190 {
 191         smp_call_function(stop_this_cpu, NULL, 0);
 192 }
 193
 194 int setup_profiling_timer(unsigned int multiplier)
 195 {
 196         return -EINVAL;
 197 }
 198
 199
 200 /* cache_decay_ticks is used by the scheduler to decide if a process
 201  * is "hot" on one CPU. A higher value means a higher penalty to move
 202  * a process to another CPU. Our cache is rather small so we report
 203  * 1 tick.
 204  */
 205 unsigned long cache_decay_ticks = 1;
 206
 207 int __cpuinit __cpu_up(unsigned int cpu)
 208 {
 209         smp_boot_one_cpu(cpu);
 210         return cpu_online(cpu) ? 0 : -ENOSYS;
 211 }
 212
 213 void smp_send_reschedule(int cpu)
 214 {
 215         cpumask_t cpu_mask = CPU_MASK_NONE;
 216         cpu_set(cpu, cpu_mask);
 217         send_ipi(IPI_SCHEDULE, 0, cpu_mask);
 218 }
 219
 220 /* TLB flushing
 221  *
 222  * Flush needs to be done on the local CPU and on any other CPU that
 223  * may have the same mapping. The mm->cpu_vm_mask is used to keep track
 224  * of which CPUs that a specific process has been executed on.
 225  */
 226 void flush_tlb_common(struct mm_struct* mm, struct vm_area_struct* vma, unsigned long addr)
 227 {
 228         unsigned long flags;
 229         cpumask_t cpu_mask;
 230
 231         spin_lock_irqsave(&tlbstate_lock, flags);
 232         cpu_mask = (mm == FLUSH_ALL ? cpu_all_mask : *mm_cpumask(mm));
 233         cpu_clear(smp_processor_id(), cpu_mask);
 234         flush_mm = mm;
 235         flush_vma = vma;
 236         flush_addr = addr;
 237         send_ipi(IPI_FLUSH_TLB, 1, cpu_mask);
 238         spin_unlock_irqrestore(&tlbstate_lock, flags);
 239 }
 240
 241 void flush_tlb_all(void)
 242 {
 243         __flush_tlb_all();
 244         flush_tlb_common(FLUSH_ALL, FLUSH_ALL, 0);
 245 }
 246
 247 void flush_tlb_mm(struct mm_struct *mm)
 248 {
 249         __flush_tlb_mm(mm);
 250         flush_tlb_common(mm, FLUSH_ALL, 0);
 251         /* No more mappings in other CPUs */
 252         cpumask_clear(mm_cpumask(mm));
 253         cpumask_set_cpu(smp_processor_id(), mm_cpumask(mm));
 254 }
 255
 256 void flush_tlb_page(struct vm_area_struct *vma,
 257                            unsigned long addr)
 258 {
 259         __flush_tlb_page(vma, addr);
 260         flush_tlb_common(vma->vm_mm, vma, addr);
 261 }
 262
 263 /* Inter processor interrupts
 264  *
 265  * The IPIs are used for:
 266  *   * Force a schedule on a CPU
 267  *   * FLush TLB on other CPUs
 268  *   * Call a function on other CPUs
 269  */
 270
 271 int send_ipi(int vector, int wait, cpumask_t cpu_mask)
 272 {
 273         int i = 0;
 274         reg_intr_vect_rw_ipi ipi = REG_RD(intr_vect, irq_regs[i], rw_ipi);
 275         int ret = 0;
 276
 277         /* Calculate CPUs to send to. */
 278         cpus_and(cpu_mask, cpu_mask, cpu_online_map);
 279
 280         /* Send the IPI. */
 281         for_each_cpu_mask(i, cpu_mask)
 282         {
 283                 ipi.vector |= vector;
 284                 REG_WR(intr_vect, irq_regs[i], rw_ipi, ipi);
 285         }
 286
 287         /* Wait for IPI to finish on other CPUS */
 288         if (wait) {
 289                 for_each_cpu_mask(i, cpu_mask) {
 290                         int j;
 291                         for (j = 0 ; j < 1000; j++) {
 292                                 ipi = REG_RD(intr_vect, irq_regs[i], rw_ipi);
 293                                 if (!ipi.vector)
 294                                         break;
 295                                 udelay(100);
 296                         }
 297
 298                         /* Timeout? */
 299                         if (ipi.vector) {
 300                                 printk("SMP call timeout from %d to %d\n", smp_processor_id(), i);
 301                                 ret = -ETIMEDOUT;
 302                                 dump_stack();
 303                         }
 304                 }
 305         }
 306         return ret;
 307 }
 308
 309 /*
 310  * You must not call this function with disabled interrupts or from a
 311  * hardware interrupt handler or from a bottom half handler.
 312  */
 313 int smp_call_function(void (*func)(void *info), void *info, int wait)
 314 {
 315         cpumask_t cpu_mask = CPU_MASK_ALL;
 316         struct call_data_struct data;
 317         int ret;
 318
 319         cpu_clear(smp_processor_id(), cpu_mask);
 320
 321         WARN_ON(irqs_disabled());
 322
 323         data.func = func;
 324         data.info = info;
 325         data.wait = wait;
 326
 327         spin_lock(&call_lock);
 328         call_data = &data;
 329         ret = send_ipi(IPI_CALL, wait, cpu_mask);
 330         spin_unlock(&call_lock);
 331
 332         return ret;
 333 }
 334
 335 irqreturn_t crisv32_ipi_interrupt(int irq, void *dev_id)
 336 {
 337         void (*func) (void *info) = call_data->func;
 338         void *info = call_data->info;
 339         reg_intr_vect_rw_ipi ipi;
 340
 341         ipi = REG_RD(intr_vect, irq_regs[smp_processor_id()], rw_ipi);
 342
 343         if (ipi.vector & IPI_CALL) {
 344                  func(info);
 345         }
 346         if (ipi.vector & IPI_FLUSH_TLB) {
 347                      if (flush_mm == FLUSH_ALL)
 348                          __flush_tlb_all();
 349                      else if (flush_vma == FLUSH_ALL)
 350                         __flush_tlb_mm(flush_mm);
 351                      else
 352                         __flush_tlb_page(flush_vma, flush_addr);
 353         }
 354
 355         ipi.vector = 0;
 356         REG_WR(intr_vect, irq_regs[smp_processor_id()], rw_ipi, ipi);
 357
 358         return IRQ_HANDLED;
 359 }
 360