arch/mips64/kernel/smp.c

   1 #include <linux/config.h>
   2 #include <linux/init.h>
   3 #include <linux/spinlock.h>
   4 #include <linux/threads.h>
   5 #include <linux/time.h>
   6 #include <linux/timex.h>
   7 #include <linux/sched.h>
   8
   9 #include <asm/atomic.h>
  10 #include <asm/processor.h>
  11 #include <asm/system.h>
  12 #include <asm/hardirq.h>
  13 #include <asm/softirq.h>
  14 #include <asm/mmu_context.h>
  15
  16 #ifdef CONFIG_SGI_IP27
  17
  18 #include <asm/sn/arch.h>
  19 #include <asm/sn/intr.h>
  20 #include <asm/sn/addrs.h>
  21 #include <asm/sn/agent.h>
  22 #include <asm/sn/sn0/ip27.h>
  23
  24 #define DORESCHED       0xab
  25 #define DOCALL          0xbc
  26
  27 #define IRQ_TO_SWLEVEL(i)       i + 7   /* Delete this from here */
  28
  29 static void sendintr(int destid, unsigned char status)
  30 {
  31         int irq;
  32
  33 #if (CPUS_PER_NODE == 2)
  34         switch (status) {
  35                 case DORESCHED: irq = CPU_RESCHED_A_IRQ; break;
  36                 case DOCALL:    irq = CPU_CALL_A_IRQ; break;
  37                 default:        panic("sendintr");
  38         }
  39         irq += cputoslice(destid);
  40
  41         /*
  42          * Convert the compact hub number to the NASID to get the correct
  43          * part of the address space.  Then set the interrupt bit associated
  44          * with the CPU we want to send the interrupt to.
  45          */
  46         REMOTE_HUB_SEND_INTR(COMPACT_TO_NASID_NODEID(cputocnode(destid)),
  47                         IRQ_TO_SWLEVEL(irq));
  48 #else
  49         << Bomb!  Must redefine this for more than 2 CPUS. >>
  50 #endif
  51 }
  52
  53 #endif /* CONFIG_SGI_IP27 */
  54
  55 /* The 'big kernel lock' */
  56 spinlock_t kernel_flag = SPIN_LOCK_UNLOCKED;
  57 int smp_threads_ready;  /* Not used */
  58 atomic_t smp_commenced = ATOMIC_INIT(0);
  59 struct cpuinfo_mips cpu_data[NR_CPUS];
  60 int smp_num_cpus;               /* Number that came online.  */
  61 int __cpu_number_map[NR_CPUS];
  62 int __cpu_logical_map[NR_CPUS];
  63 cycles_t cacheflush_time;
  64
  65 static void smp_tune_scheduling (void)
  66 {
  67 }
  68
  69 void __init smp_boot_cpus(void)
  70 {
  71         extern void allowboot(void);
  72
  73         init_new_context(current, &init_mm);
  74         current->processor = 0;
  75         init_idle();
  76         smp_tune_scheduling();
  77         allowboot();
  78 }
  79
  80 void __init smp_commence(void)
  81 {
  82         wmb();
  83         atomic_set(&smp_commenced,1);
  84 }
  85
  86 static void stop_this_cpu(void *dummy)
  87 {
  88         /*
  89          * Remove this CPU
  90          */
  91         for (;;);
  92 }
  93
  94 void smp_send_stop(void)
  95 {
  96         smp_call_function(stop_this_cpu, NULL, 1, 0);
  97         smp_num_cpus = 1;
  98 }
  99
 100 /*
 101  * this function sends a 'reschedule' IPI to another CPU.
 102  * it goes straight through and wastes no time serializing
 103  * anything. Worst case is that we lose a reschedule ...
 104  */
 105 void smp_send_reschedule(int cpu)
 106 {
 107         sendintr(cpu, DORESCHED);
 108 }
 109
 110 /* Not really SMP stuff ... */
 111 int setup_profiling_timer(unsigned int multiplier)
 112 {
 113         return 0;
 114 }
 115
 116 /*
 117  * Run a function on all other CPUs.
 118  *  <func>      The function to run. This must be fast and non-blocking.
 119  *  <info>      An arbitrary pointer to pass to the function.
 120  *  <retry>     If true, keep retrying until ready.
 121  *  <wait>      If true, wait until function has completed on other CPUs.
 122  *  [RETURNS]   0 on success, else a negative status code.
 123  *
 124  * Does not return until remote CPUs are nearly ready to execute <func>
 125  * or are or have executed.
 126  */
 127 static volatile struct call_data_struct {
 128         void (*func) (void *info);
 129         void *info;
 130         atomic_t started;
 131         atomic_t finished;
 132         int wait;
 133 } *call_data;
 134
 135 int smp_call_function (void (*func) (void *info), void *info, int retry,
 136                                                                 int wait)
 137 {
 138         struct call_data_struct data;
 139         int i, cpus = smp_num_cpus-1;
 140         static spinlock_t lock = SPIN_LOCK_UNLOCKED;
 141
 142         if (cpus == 0)
 143                 return 0;
 144
 145         data.func = func;
 146         data.info = info;
 147         atomic_set(&data.started, 0);
 148         data.wait = wait;
 149         if (wait)
 150                 atomic_set(&data.finished, 0);
 151
 152         spin_lock_bh(&lock);
 153         call_data = &data;
 154         /* Send a message to all other CPUs and wait for them to respond */
 155         for (i = 0; i < smp_num_cpus; i++)
 156                 if (smp_processor_id() != i)
 157                         sendintr(i, DOCALL);
 158
 159         /* Wait for response */
 160         /* FIXME: lock-up detection, backtrace on lock-up */
 161         while (atomic_read(&data.started) != cpus)
 162                 barrier();
 163
 164         if (wait)
 165                 while (atomic_read(&data.finished) != cpus)
 166                         barrier();
 167         spin_unlock_bh(&lock);
 168         return 0;
 169 }
 170
 171 extern void smp_call_function_interrupt(int irq, void *d, struct pt_regs *r)
 172 {
 173         void (*func) (void *info) = call_data->func;
 174         void *info = call_data->info;
 175         int wait = call_data->wait;
 176
 177         /*
 178          * Notify initiating CPU that I've grabbed the data and am
 179          * about to execute the function.
 180          */
 181         atomic_inc(&call_data->started);
 182
 183         /*
 184          * At this point the info structure may be out of scope unless wait==1.
 185          */
 186         (*func)(info);
 187         if (wait)
 188                 atomic_inc(&call_data->finished);
 189 }
 190
 191
 192 static void flush_tlb_all_ipi(void *info)
 193 {
 194         _flush_tlb_all();
 195 }
 196
 197 void flush_tlb_all(void)
 198 {
 199         smp_call_function(flush_tlb_all_ipi, 0, 1, 1);
 200         _flush_tlb_all();
 201 }
 202
 203 static void flush_tlb_mm_ipi(void *mm)
 204 {
 205         _flush_tlb_mm((struct mm_struct *)mm);
 206 }
 207
 208 /*
 209  * The following tlb flush calls are invoked when old translations are
 210  * being torn down, or pte attributes are changing. For single threaded
 211  * address spaces, a new context is obtained on the current cpu, and tlb
 212  * context on other cpus are invalidated to force a new context allocation
 213  * at switch_mm time, should the mm ever be used on other cpus. For
 214  * multithreaded address spaces, intercpu interrupts have to be sent.
 215  * Another case where intercpu interrupts are required is when the target
 216  * mm might be active on another cpu (eg debuggers doing the flushes on
 217  * behalf of debugees, kswapd stealing pages from another process etc).
 218  * Kanoj 07/00.
 219  */
 220
 221 void flush_tlb_mm(struct mm_struct *mm)
 222 {
 223         if ((atomic_read(&mm->mm_users) != 1) || (current->mm != mm)) {
 224                 smp_call_function(flush_tlb_mm_ipi, (void *)mm, 1, 1);
 225         } else {
 226                 int i;
 227                 for (i = 0; i < smp_num_cpus; i++)
 228                         if (smp_processor_id() != i)
 229                                 CPU_CONTEXT(i, mm) = 0;
 230         }
 231         _flush_tlb_mm(mm);
 232 }
 233
 234 struct flush_tlb_data {
 235         struct mm_struct *mm;
 236         struct vm_area_struct *vma;
 237         unsigned long addr1;
 238         unsigned long addr2;
 239 };
 240
 241 static void flush_tlb_range_ipi(void *info)
 242 {
 243         struct flush_tlb_data *fd = (struct flush_tlb_data *)info;
 244
 245         _flush_tlb_range(fd->mm, fd->addr1, fd->addr2);
 246 }
 247
 248 void flush_tlb_range(struct mm_struct *mm, unsigned long start, unsigned long end)
 249 {
 250         if ((atomic_read(&mm->mm_users) != 1) || (current->mm != mm)) {
 251                 struct flush_tlb_data fd;
 252
 253                 fd.mm = mm;
 254                 fd.addr1 = start;
 255                 fd.addr2 = end;
 256                 smp_call_function(flush_tlb_range_ipi, (void *)&fd, 1, 1);
 257         } else {
 258                 int i;
 259                 for (i = 0; i < smp_num_cpus; i++)
 260                         if (smp_processor_id() != i)
 261                                 CPU_CONTEXT(i, mm) = 0;
 262         }
 263         _flush_tlb_range(mm, start, end);
 264 }
 265
 266 static void flush_tlb_page_ipi(void *info)
 267 {
 268         struct flush_tlb_data *fd = (struct flush_tlb_data *)info;
 269
 270         _flush_tlb_page(fd->vma, fd->addr1);
 271 }
 272
 273 void flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
 274 {
 275         if ((atomic_read(&vma->vm_mm->mm_users) != 1) || (current->mm != vma->vm_mm)) {
 276                 struct flush_tlb_data fd;
 277
 278                 fd.vma = vma;
 279                 fd.addr1 = page;
 280                 smp_call_function(flush_tlb_page_ipi, (void *)&fd, 1, 1);
 281         } else {
 282                 int i;
 283                 for (i = 0; i < smp_num_cpus; i++)
 284                         if (smp_processor_id() != i)
 285                                 CPU_CONTEXT(i, vma->vm_mm) = 0;
 286         }
 287         _flush_tlb_page(vma, page);
 288 }
 289