root/arch/sparc/kernel/sun4d_smp.c

DEFINITIONS

1. sun4d_swap
2. show_leds
3. sun4d_cpu_pre_starting
4. sun4d_cpu_pre_online
5. smp4d_boot_cpus
6. smp4d_boot_one_cpu
7. smp4d_smp_done
8. smp4d_ipi_init
9. sun4d_ipi_interrupt
10. sun4d_send_ipi
11. sun4d_ipi_single
12. sun4d_ipi_mask_one
13. sun4d_ipi_resched
14. sun4d_cross_call
15. smp4d_cross_call_irq
16. smp4d_percpu_timer_interrupt
17. sun4d_init_smp

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* Sparc SS1000/SC2000 SMP support.
   3  *
   4  * Copyright (C) 1998 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
   5  *
   6  * Based on sun4m's smp.c, which is:
   7  * Copyright (C) 1996 David S. Miller (davem@caip.rutgers.edu)
   8  */
   9 
  10 #include <linux/clockchips.h>
  11 #include <linux/interrupt.h>
  12 #include <linux/profile.h>
  13 #include <linux/delay.h>
  14 #include <linux/sched/mm.h>
  15 #include <linux/cpu.h>
  16 
  17 #include <asm/cacheflush.h>
  18 #include <asm/switch_to.h>
  19 #include <asm/tlbflush.h>
  20 #include <asm/timer.h>
  21 #include <asm/oplib.h>
  22 #include <asm/sbi.h>
  23 #include <asm/mmu.h>
  24 
  25 #include "kernel.h"
  26 #include "irq.h"
  27 
  28 #define IRQ_CROSS_CALL          15
  29 
  30 static volatile int smp_processors_ready;
  31 static int smp_highest_cpu;
  32 
  33 static inline unsigned long sun4d_swap(volatile unsigned long *ptr, unsigned long val)
  34 {
  35         __asm__ __volatile__("swap [%1], %0\n\t" :
  36                              "=&r" (val), "=&r" (ptr) :
  37                              "0" (val), "1" (ptr));
  38         return val;
  39 }
  40 
  41 static void smp4d_ipi_init(void);
  42 
  43 static unsigned char cpu_leds[32];
  44 
  45 static inline void show_leds(int cpuid)
  46 {
  47         cpuid &= 0x1e;
  48         __asm__ __volatile__ ("stba %0, [%1] %2" : :
  49                               "r" ((cpu_leds[cpuid] << 4) | cpu_leds[cpuid+1]),
  50                               "r" (ECSR_BASE(cpuid) | BB_LEDS),
  51                               "i" (ASI_M_CTL));
  52 }
  53 
  54 void sun4d_cpu_pre_starting(void *arg)
  55 {
  56         int cpuid = hard_smp_processor_id();
  57 
  58         /* Show we are alive */
  59         cpu_leds[cpuid] = 0x6;
  60         show_leds(cpuid);
  61 
  62         /* Enable level15 interrupt, disable level14 interrupt for now */
  63         cc_set_imsk((cc_get_imsk() & ~0x8000) | 0x4000);
  64 }
  65 
  66 void sun4d_cpu_pre_online(void *arg)
  67 {
  68         unsigned long flags;
  69         int cpuid;
  70 
  71         cpuid = hard_smp_processor_id();
  72 
  73         /* Unblock the master CPU _only_ when the scheduler state
  74          * of all secondary CPUs will be up-to-date, so after
  75          * the SMP initialization the master will be just allowed
  76          * to call the scheduler code.
  77          */
  78         sun4d_swap((unsigned long *)&cpu_callin_map[cpuid], 1);
  79         local_ops->cache_all();
  80         local_ops->tlb_all();
  81 
  82         while ((unsigned long)current_set[cpuid] < PAGE_OFFSET)
  83                 barrier();
  84 
  85         while (current_set[cpuid]->cpu != cpuid)
  86                 barrier();
  87 
  88         /* Fix idle thread fields. */
  89         __asm__ __volatile__("ld [%0], %%g6\n\t"
  90                              : : "r" (&current_set[cpuid])
  91                              : "memory" /* paranoid */);
  92 
  93         cpu_leds[cpuid] = 0x9;
  94         show_leds(cpuid);
  95 
  96         /* Attach to the address space of init_task. */
  97         mmgrab(&init_mm);
  98         current->active_mm = &init_mm;
  99 
 100         local_ops->cache_all();
 101         local_ops->tlb_all();
 102 
 103         while (!cpumask_test_cpu(cpuid, &smp_commenced_mask))
 104                 barrier();
 105 
 106         spin_lock_irqsave(&sun4d_imsk_lock, flags);
 107         cc_set_imsk(cc_get_imsk() & ~0x4000); /* Allow PIL 14 as well */
 108         spin_unlock_irqrestore(&sun4d_imsk_lock, flags);
 109 }
 110 
 111 /*
 112  *      Cycle through the processors asking the PROM to start each one.
 113  */
 114 void __init smp4d_boot_cpus(void)
 115 {
 116         smp4d_ipi_init();
 117         if (boot_cpu_id)
 118                 current_set[0] = NULL;
 119         local_ops->cache_all();
 120 }
 121 
 122 int smp4d_boot_one_cpu(int i, struct task_struct *idle)
 123 {
 124         unsigned long *entry = &sun4d_cpu_startup;
 125         int timeout;
 126         int cpu_node;
 127 
 128         cpu_find_by_instance(i, &cpu_node, NULL);
 129         current_set[i] = task_thread_info(idle);
 130         /*
 131          * Initialize the contexts table
 132          * Since the call to prom_startcpu() trashes the structure,
 133          * we need to re-initialize it for each cpu
 134          */
 135         smp_penguin_ctable.which_io = 0;
 136         smp_penguin_ctable.phys_addr = (unsigned int) srmmu_ctx_table_phys;
 137         smp_penguin_ctable.reg_size = 0;
 138 
 139         /* whirrr, whirrr, whirrrrrrrrr... */
 140         printk(KERN_INFO "Starting CPU %d at %p\n", i, entry);
 141         local_ops->cache_all();
 142         prom_startcpu(cpu_node,
 143                       &smp_penguin_ctable, 0, (char *)entry);
 144 
 145         printk(KERN_INFO "prom_startcpu returned :)\n");
 146 
 147         /* wheee... it's going... */
 148         for (timeout = 0; timeout < 10000; timeout++) {
 149                 if (cpu_callin_map[i])
 150                         break;
 151                 udelay(200);
 152         }
 153 
 154         if (!(cpu_callin_map[i])) {
 155                 printk(KERN_ERR "Processor %d is stuck.\n", i);
 156                 return -ENODEV;
 157 
 158         }
 159         local_ops->cache_all();
 160         return 0;
 161 }
 162 
 163 void __init smp4d_smp_done(void)
 164 {
 165         int i, first;
 166         int *prev;
 167 
 168         /* setup cpu list for irq rotation */
 169         first = 0;
 170         prev = &first;
 171         for_each_online_cpu(i) {
 172                 *prev = i;
 173                 prev = &cpu_data(i).next;
 174         }
 175         *prev = first;
 176         local_ops->cache_all();
 177 
 178         /* Ok, they are spinning and ready to go. */
 179         smp_processors_ready = 1;
 180         sun4d_distribute_irqs();
 181 }
 182 
 183 /* Memory structure giving interrupt handler information about IPI generated */
 184 struct sun4d_ipi_work {
 185         int single;
 186         int msk;
 187         int resched;
 188 };
 189 
 190 static DEFINE_PER_CPU_SHARED_ALIGNED(struct sun4d_ipi_work, sun4d_ipi_work);
 191 
 192 /* Initialize IPIs on the SUN4D SMP machine */
 193 static void __init smp4d_ipi_init(void)
 194 {
 195         int cpu;
 196         struct sun4d_ipi_work *work;
 197 
 198         printk(KERN_INFO "smp4d: setup IPI at IRQ %d\n", SUN4D_IPI_IRQ);
 199 
 200         for_each_possible_cpu(cpu) {
 201                 work = &per_cpu(sun4d_ipi_work, cpu);
 202                 work->single = work->msk = work->resched = 0;
 203         }
 204 }
 205 
 206 void sun4d_ipi_interrupt(void)
 207 {
 208         struct sun4d_ipi_work *work = this_cpu_ptr(&sun4d_ipi_work);
 209 
 210         if (work->single) {
 211                 work->single = 0;
 212                 smp_call_function_single_interrupt();
 213         }
 214         if (work->msk) {
 215                 work->msk = 0;
 216                 smp_call_function_interrupt();
 217         }
 218         if (work->resched) {
 219                 work->resched = 0;
 220                 smp_resched_interrupt();
 221         }
 222 }
 223 
 224 /* +-------+-------------+-----------+------------------------------------+
 225  * | bcast |  devid      |   sid     |              levels mask           |
 226  * +-------+-------------+-----------+------------------------------------+
 227  *  31      30         23 22       15 14                                 0
 228  */
 229 #define IGEN_MESSAGE(bcast, devid, sid, levels) \
 230         (((bcast) << 31) | ((devid) << 23) | ((sid) << 15) | (levels))
 231 
 232 static void sun4d_send_ipi(int cpu, int level)
 233 {
 234         cc_set_igen(IGEN_MESSAGE(0, cpu << 3, 6 + ((level >> 1) & 7), 1 << (level - 1)));
 235 }
 236 
 237 static void sun4d_ipi_single(int cpu)
 238 {
 239         struct sun4d_ipi_work *work = &per_cpu(sun4d_ipi_work, cpu);
 240 
 241         /* Mark work */
 242         work->single = 1;
 243 
 244         /* Generate IRQ on the CPU */
 245         sun4d_send_ipi(cpu, SUN4D_IPI_IRQ);
 246 }
 247 
 248 static void sun4d_ipi_mask_one(int cpu)
 249 {
 250         struct sun4d_ipi_work *work = &per_cpu(sun4d_ipi_work, cpu);
 251 
 252         /* Mark work */
 253         work->msk = 1;
 254 
 255         /* Generate IRQ on the CPU */
 256         sun4d_send_ipi(cpu, SUN4D_IPI_IRQ);
 257 }
 258 
 259 static void sun4d_ipi_resched(int cpu)
 260 {
 261         struct sun4d_ipi_work *work = &per_cpu(sun4d_ipi_work, cpu);
 262 
 263         /* Mark work */
 264         work->resched = 1;
 265 
 266         /* Generate IRQ on the CPU (any IRQ will cause resched) */
 267         sun4d_send_ipi(cpu, SUN4D_IPI_IRQ);
 268 }
 269 
 270 static struct smp_funcall {
 271         smpfunc_t func;
 272         unsigned long arg1;
 273         unsigned long arg2;
 274         unsigned long arg3;
 275         unsigned long arg4;
 276         unsigned long arg5;
 277         unsigned char processors_in[NR_CPUS];  /* Set when ipi entered. */
 278         unsigned char processors_out[NR_CPUS]; /* Set when ipi exited. */
 279 } ccall_info __attribute__((aligned(8)));
 280 
 281 static DEFINE_SPINLOCK(cross_call_lock);
 282 
 283 /* Cross calls must be serialized, at least currently. */
 284 static void sun4d_cross_call(smpfunc_t func, cpumask_t mask, unsigned long arg1,
 285                              unsigned long arg2, unsigned long arg3,
 286                              unsigned long arg4)
 287 {
 288         if (smp_processors_ready) {
 289                 register int high = smp_highest_cpu;
 290                 unsigned long flags;
 291 
 292                 spin_lock_irqsave(&cross_call_lock, flags);
 293 
 294                 {
 295                         /*
 296                          * If you make changes here, make sure
 297                          * gcc generates proper code...
 298                          */
 299                         register smpfunc_t f asm("i0") = func;
 300                         register unsigned long a1 asm("i1") = arg1;
 301                         register unsigned long a2 asm("i2") = arg2;
 302                         register unsigned long a3 asm("i3") = arg3;
 303                         register unsigned long a4 asm("i4") = arg4;
 304                         register unsigned long a5 asm("i5") = 0;
 305 
 306                         __asm__ __volatile__(
 307                                 "std %0, [%6]\n\t"
 308                                 "std %2, [%6 + 8]\n\t"
 309                                 "std %4, [%6 + 16]\n\t" : :
 310                                 "r"(f), "r"(a1), "r"(a2), "r"(a3), "r"(a4), "r"(a5),
 311                                 "r" (&ccall_info.func));
 312                 }
 313 
 314                 /* Init receive/complete mapping, plus fire the IPI's off. */
 315                 {
 316                         register int i;
 317 
 318                         cpumask_clear_cpu(smp_processor_id(), &mask);
 319                         cpumask_and(&mask, cpu_online_mask, &mask);
 320                         for (i = 0; i <= high; i++) {
 321                                 if (cpumask_test_cpu(i, &mask)) {
 322                                         ccall_info.processors_in[i] = 0;
 323                                         ccall_info.processors_out[i] = 0;
 324                                         sun4d_send_ipi(i, IRQ_CROSS_CALL);
 325                                 }
 326                         }
 327                 }
 328 
 329                 {
 330                         register int i;
 331 
 332                         i = 0;
 333                         do {
 334                                 if (!cpumask_test_cpu(i, &mask))
 335                                         continue;
 336                                 while (!ccall_info.processors_in[i])
 337                                         barrier();
 338                         } while (++i <= high);
 339 
 340                         i = 0;
 341                         do {
 342                                 if (!cpumask_test_cpu(i, &mask))
 343                                         continue;
 344                                 while (!ccall_info.processors_out[i])
 345                                         barrier();
 346                         } while (++i <= high);
 347                 }
 348 
 349                 spin_unlock_irqrestore(&cross_call_lock, flags);
 350         }
 351 }
 352 
 353 /* Running cross calls. */
 354 void smp4d_cross_call_irq(void)
 355 {
 356         int i = hard_smp_processor_id();
 357 
 358         ccall_info.processors_in[i] = 1;
 359         ccall_info.func(ccall_info.arg1, ccall_info.arg2, ccall_info.arg3,
 360                         ccall_info.arg4, ccall_info.arg5);
 361         ccall_info.processors_out[i] = 1;
 362 }
 363 
 364 void smp4d_percpu_timer_interrupt(struct pt_regs *regs)
 365 {
 366         struct pt_regs *old_regs;
 367         int cpu = hard_smp_processor_id();
 368         struct clock_event_device *ce;
 369         static int cpu_tick[NR_CPUS];
 370         static char led_mask[] = { 0xe, 0xd, 0xb, 0x7, 0xb, 0xd };
 371 
 372         old_regs = set_irq_regs(regs);
 373         bw_get_prof_limit(cpu);
 374         bw_clear_intr_mask(0, 1);       /* INTR_TABLE[0] & 1 is Profile IRQ */
 375 
 376         cpu_tick[cpu]++;
 377         if (!(cpu_tick[cpu] & 15)) {
 378                 if (cpu_tick[cpu] == 0x60)
 379                         cpu_tick[cpu] = 0;
 380                 cpu_leds[cpu] = led_mask[cpu_tick[cpu] >> 4];
 381                 show_leds(cpu);
 382         }
 383 
 384         ce = &per_cpu(sparc32_clockevent, cpu);
 385 
 386         irq_enter();
 387         ce->event_handler(ce);
 388         irq_exit();
 389 
 390         set_irq_regs(old_regs);
 391 }
 392 
 393 static const struct sparc32_ipi_ops sun4d_ipi_ops = {
 394         .cross_call = sun4d_cross_call,
 395         .resched    = sun4d_ipi_resched,
 396         .single     = sun4d_ipi_single,
 397         .mask_one   = sun4d_ipi_mask_one,
 398 };
 399 
 400 void __init sun4d_init_smp(void)
 401 {
 402         int i;
 403 
 404         /* Patch ipi15 trap table */
 405         t_nmi[1] = t_nmi[1] + (linux_trap_ipi15_sun4d - linux_trap_ipi15_sun4m);
 406 
 407         sparc32_ipi_ops = &sun4d_ipi_ops;
 408 
 409         for (i = 0; i < NR_CPUS; i++) {
 410                 ccall_info.processors_in[i] = 1;
 411                 ccall_info.processors_out[i] = 1;
 412         }
 413 }