arch/sparc/kernel/leon_smp.c

   1 /* leon_smp.c: Sparc-Leon SMP support.
   2  *
   3  * based on sun4m_smp.c
   4  * Copyright (C) 1996 David S. Miller (davem@caip.rutgers.edu)
   5  * Copyright (C) 2009 Daniel Hellstrom (daniel@gaisler.com) Aeroflex Gaisler AB
   6  * Copyright (C) 2009 Konrad Eisele (konrad@gaisler.com) Aeroflex Gaisler AB
   7  */
   8
   9 #include <asm/head.h>
  10
  11 #include <linux/kernel.h>
  12 #include <linux/sched.h>
  13 #include <linux/threads.h>
  14 #include <linux/smp.h>
  15 #include <linux/interrupt.h>
  16 #include <linux/kernel_stat.h>
  17 #include <linux/of.h>
  18 #include <linux/init.h>
  19 #include <linux/spinlock.h>
  20 #include <linux/mm.h>
  21 #include <linux/swap.h>
  22 #include <linux/profile.h>
  23 #include <linux/pm.h>
  24 #include <linux/delay.h>
  25 #include <linux/gfp.h>
  26 #include <linux/cpu.h>
  27 #include <linux/clockchips.h>
  28
  29 #include <asm/cacheflush.h>
  30 #include <asm/tlbflush.h>
  31
  32 #include <asm/ptrace.h>
  33 #include <linux/atomic.h>
  34 #include <asm/irq_regs.h>
  35 #include <asm/traps.h>
  36
  37 #include <asm/delay.h>
  38 #include <asm/irq.h>
  39 #include <asm/page.h>
  40 #include <asm/pgalloc.h>
  41 #include <asm/pgtable.h>
  42 #include <asm/oplib.h>
  43 #include <asm/cpudata.h>
  44 #include <asm/asi.h>
  45 #include <asm/leon.h>
  46 #include <asm/leon_amba.h>
  47 #include <asm/timer.h>
  48
  49 #include "kernel.h"
  50
  51 #include "irq.h"
  52
  53 extern ctxd_t *srmmu_ctx_table_phys;
  54 static int smp_processors_ready;
  55 extern volatile unsigned long cpu_callin_map[NR_CPUS];
  56 extern cpumask_t smp_commenced_mask;
  57 void leon_configure_cache_smp(void);
  58 static void leon_ipi_init(void);
  59
  60 /* IRQ number of LEON IPIs */
  61 int leon_ipi_irq = LEON3_IRQ_IPI_DEFAULT;
  62
  63 static inline unsigned long do_swap(volatile unsigned long *ptr,
  64                                     unsigned long val)
  65 {
  66         __asm__ __volatile__("swapa [%2] %3, %0\n\t" : "=&r"(val)
  67                              : "0"(val), "r"(ptr), "i"(ASI_LEON_DCACHE_MISS)
  68                              : "memory");
  69         return val;
  70 }
  71
  72 void leon_cpu_pre_starting(void *arg)
  73 {
  74         leon_configure_cache_smp();
  75 }
  76
  77 void leon_cpu_pre_online(void *arg)
  78 {
  79         int cpuid = hard_smp_processor_id();
  80
  81         /* Allow master to continue. The master will then give us the
  82          * go-ahead by setting the smp_commenced_mask and will wait without
  83          * timeouts until our setup is completed fully (signified by
  84          * our bit being set in the cpu_online_mask).
  85          */
  86         do_swap(&cpu_callin_map[cpuid], 1);
  87
  88         local_ops->cache_all();
  89         local_ops->tlb_all();
  90
  91         /* Fix idle thread fields. */
  92         __asm__ __volatile__("ld [%0], %%g6\n\t" : : "r"(&current_set[cpuid])
  93                              : "memory" /* paranoid */);
  94
  95         /* Attach to the address space of init_task. */
  96         atomic_inc(&init_mm.mm_count);
  97         current->active_mm = &init_mm;
  98
  99         while (!cpumask_test_cpu(cpuid, &smp_commenced_mask))
 100                 mb();
 101 }
 102
 103 /*
 104  *      Cycle through the processors asking the PROM to start each one.
 105  */
 106
 107 extern struct linux_prom_registers smp_penguin_ctable;
 108
 109 void leon_configure_cache_smp(void)
 110 {
 111         unsigned long cfg = sparc_leon3_get_dcachecfg();
 112         int me = smp_processor_id();
 113
 114         if (ASI_LEON3_SYSCTRL_CFG_SSIZE(cfg) > 4) {
 115                 printk(KERN_INFO "Note: SMP with snooping only works on 4k cache, found %dk(0x%x) on cpu %d, disabling caches\n",
 116                      (unsigned int)ASI_LEON3_SYSCTRL_CFG_SSIZE(cfg),
 117                      (unsigned int)cfg, (unsigned int)me);
 118                 sparc_leon3_disable_cache();
 119         } else {
 120                 if (cfg & ASI_LEON3_SYSCTRL_CFG_SNOOPING) {
 121                         sparc_leon3_enable_snooping();
 122                 } else {
 123                         printk(KERN_INFO "Note: You have to enable snooping in the vhdl model cpu %d, disabling caches\n",
 124                              me);
 125                         sparc_leon3_disable_cache();
 126                 }
 127         }
 128
 129         local_ops->cache_all();
 130         local_ops->tlb_all();
 131 }
 132
 133 void leon_smp_setbroadcast(unsigned int mask)
 134 {
 135         int broadcast =
 136             ((LEON3_BYPASS_LOAD_PA(&(leon3_irqctrl_regs->mpstatus)) >>
 137               LEON3_IRQMPSTATUS_BROADCAST) & 1);
 138         if (!broadcast) {
 139                 prom_printf("######## !!!! The irqmp-ctrl must have broadcast enabled, smp wont work !!!!! ####### nr cpus: %d\n",
 140                      leon_smp_nrcpus());
 141                 if (leon_smp_nrcpus() > 1) {
 142                         BUG();
 143                 } else {
 144                         prom_printf("continue anyway\n");
 145                         return;
 146                 }
 147         }
 148         LEON_BYPASS_STORE_PA(&(leon3_irqctrl_regs->mpbroadcast), mask);
 149 }
 150
 151 unsigned int leon_smp_getbroadcast(void)
 152 {
 153         unsigned int mask;
 154         mask = LEON_BYPASS_LOAD_PA(&(leon3_irqctrl_regs->mpbroadcast));
 155         return mask;
 156 }
 157
 158 int leon_smp_nrcpus(void)
 159 {
 160         int nrcpu =
 161             ((LEON3_BYPASS_LOAD_PA(&(leon3_irqctrl_regs->mpstatus)) >>
 162               LEON3_IRQMPSTATUS_CPUNR) & 0xf) + 1;
 163         return nrcpu;
 164 }
 165
 166 void __init leon_boot_cpus(void)
 167 {
 168         int nrcpu = leon_smp_nrcpus();
 169         int me = smp_processor_id();
 170
 171         /* Setup IPI */
 172         leon_ipi_init();
 173
 174         printk(KERN_INFO "%d:(%d:%d) cpus mpirq at 0x%x\n", (unsigned int)me,
 175                (unsigned int)nrcpu, (unsigned int)NR_CPUS,
 176                (unsigned int)&(leon3_irqctrl_regs->mpstatus));
 177
 178         leon_enable_irq_cpu(LEON3_IRQ_CROSS_CALL, me);
 179         leon_enable_irq_cpu(LEON3_IRQ_TICKER, me);
 180         leon_enable_irq_cpu(leon_ipi_irq, me);
 181
 182         leon_smp_setbroadcast(1 << LEON3_IRQ_TICKER);
 183
 184         leon_configure_cache_smp();
 185         local_ops->cache_all();
 186
 187 }
 188
 189 int leon_boot_one_cpu(int i, struct task_struct *idle)
 190 {
 191         int timeout;
 192
 193         current_set[i] = task_thread_info(idle);
 194
 195         /* See trampoline.S:leon_smp_cpu_startup for details...
 196          * Initialize the contexts table
 197          * Since the call to prom_startcpu() trashes the structure,
 198          * we need to re-initialize it for each cpu
 199          */
 200         smp_penguin_ctable.which_io = 0;
 201         smp_penguin_ctable.phys_addr = (unsigned int)srmmu_ctx_table_phys;
 202         smp_penguin_ctable.reg_size = 0;
 203
 204         /* whirrr, whirrr, whirrrrrrrrr... */
 205         printk(KERN_INFO "Starting CPU %d : (irqmp: 0x%x)\n", (unsigned int)i,
 206                (unsigned int)&leon3_irqctrl_regs->mpstatus);
 207         local_ops->cache_all();
 208
 209         /* Make sure all IRQs are of from the start for this new CPU */
 210         LEON_BYPASS_STORE_PA(&leon3_irqctrl_regs->mask[i], 0);
 211
 212         /* Wake one CPU */
 213         LEON_BYPASS_STORE_PA(&(leon3_irqctrl_regs->mpstatus), 1 << i);
 214
 215         /* wheee... it's going... */
 216         for (timeout = 0; timeout < 10000; timeout++) {
 217                 if (cpu_callin_map[i])
 218                         break;
 219                 udelay(200);
 220         }
 221         printk(KERN_INFO "Started CPU %d\n", (unsigned int)i);
 222
 223         if (!(cpu_callin_map[i])) {
 224                 printk(KERN_ERR "Processor %d is stuck.\n", i);
 225                 return -ENODEV;
 226         } else {
 227                 leon_enable_irq_cpu(LEON3_IRQ_CROSS_CALL, i);
 228                 leon_enable_irq_cpu(LEON3_IRQ_TICKER, i);
 229                 leon_enable_irq_cpu(leon_ipi_irq, i);
 230         }
 231
 232         local_ops->cache_all();
 233         return 0;
 234 }
 235
 236 void __init leon_smp_done(void)
 237 {
 238
 239         int i, first;
 240         int *prev;
 241
 242         /* setup cpu list for irq rotation */
 243         first = 0;
 244         prev = &first;
 245         for (i = 0; i < NR_CPUS; i++) {
 246                 if (cpu_online(i)) {
 247                         *prev = i;
 248                         prev = &cpu_data(i).next;
 249                 }
 250         }
 251         *prev = first;
 252         local_ops->cache_all();
 253
 254         /* Free unneeded trap tables */
 255         if (!cpu_present(1)) {
 256                 free_reserved_page(virt_to_page(&trapbase_cpu1));
 257         }
 258         if (!cpu_present(2)) {
 259                 free_reserved_page(virt_to_page(&trapbase_cpu2));
 260         }
 261         if (!cpu_present(3)) {
 262                 free_reserved_page(virt_to_page(&trapbase_cpu3));
 263         }
 264         /* Ok, they are spinning and ready to go. */
 265         smp_processors_ready = 1;
 266
 267 }
 268
 269 void leon_irq_rotate(int cpu)
 270 {
 271 }
 272
 273 struct leon_ipi_work {
 274         int single;
 275         int msk;
 276         int resched;
 277 };
 278
 279 static DEFINE_PER_CPU_SHARED_ALIGNED(struct leon_ipi_work, leon_ipi_work);
 280
 281 /* Initialize IPIs on the LEON, in order to save IRQ resources only one IRQ
 282  * is used for all three types of IPIs.
 283  */
 284 static void __init leon_ipi_init(void)
 285 {
 286         int cpu, len;
 287         struct leon_ipi_work *work;
 288         struct property *pp;
 289         struct device_node *rootnp;
 290         struct tt_entry *trap_table;
 291         unsigned long flags;
 292
 293         /* Find IPI IRQ or stick with default value */
 294         rootnp = of_find_node_by_path("/ambapp0");
 295         if (rootnp) {
 296                 pp = of_find_property(rootnp, "ipi_num", &len);
 297                 if (pp && (*(int *)pp->value))
 298                         leon_ipi_irq = *(int *)pp->value;
 299         }
 300         printk(KERN_INFO "leon: SMP IPIs at IRQ %d\n", leon_ipi_irq);
 301
 302         /* Adjust so that we jump directly to smpleon_ipi */
 303         local_irq_save(flags);
 304         trap_table = &sparc_ttable[SP_TRAP_IRQ1 + (leon_ipi_irq - 1)];
 305         trap_table->inst_three += smpleon_ipi - real_irq_entry;
 306         local_ops->cache_all();
 307         local_irq_restore(flags);
 308
 309         for_each_possible_cpu(cpu) {
 310                 work = &per_cpu(leon_ipi_work, cpu);
 311                 work->single = work->msk = work->resched = 0;
 312         }
 313 }
 314
 315 static void leon_send_ipi(int cpu, int level)
 316 {
 317         unsigned long mask;
 318         mask = leon_get_irqmask(level);
 319         LEON3_BYPASS_STORE_PA(&leon3_irqctrl_regs->force[cpu], mask);
 320 }
 321
 322 static void leon_ipi_single(int cpu)
 323 {
 324         struct leon_ipi_work *work = &per_cpu(leon_ipi_work, cpu);
 325
 326         /* Mark work */
 327         work->single = 1;
 328
 329         /* Generate IRQ on the CPU */
 330         leon_send_ipi(cpu, leon_ipi_irq);
 331 }
 332
 333 static void leon_ipi_mask_one(int cpu)
 334 {
 335         struct leon_ipi_work *work = &per_cpu(leon_ipi_work, cpu);
 336
 337         /* Mark work */
 338         work->msk = 1;
 339
 340         /* Generate IRQ on the CPU */
 341         leon_send_ipi(cpu, leon_ipi_irq);
 342 }
 343
 344 static void leon_ipi_resched(int cpu)
 345 {
 346         struct leon_ipi_work *work = &per_cpu(leon_ipi_work, cpu);
 347
 348         /* Mark work */
 349         work->resched = 1;
 350
 351         /* Generate IRQ on the CPU (any IRQ will cause resched) */
 352         leon_send_ipi(cpu, leon_ipi_irq);
 353 }
 354
 355 void leonsmp_ipi_interrupt(void)
 356 {
 357         struct leon_ipi_work *work = &__get_cpu_var(leon_ipi_work);
 358
 359         if (work->single) {
 360                 work->single = 0;
 361                 smp_call_function_single_interrupt();
 362         }
 363         if (work->msk) {
 364                 work->msk = 0;
 365                 smp_call_function_interrupt();
 366         }
 367         if (work->resched) {
 368                 work->resched = 0;
 369                 smp_resched_interrupt();
 370         }
 371 }
 372
 373 static struct smp_funcall {
 374         smpfunc_t func;
 375         unsigned long arg1;
 376         unsigned long arg2;
 377         unsigned long arg3;
 378         unsigned long arg4;
 379         unsigned long arg5;
 380         unsigned long processors_in[NR_CPUS];   /* Set when ipi entered. */
 381         unsigned long processors_out[NR_CPUS];  /* Set when ipi exited. */
 382 } ccall_info;
 383
 384 static DEFINE_SPINLOCK(cross_call_lock);
 385
 386 /* Cross calls must be serialized, at least currently. */
 387 static void leon_cross_call(smpfunc_t func, cpumask_t mask, unsigned long arg1,
 388                             unsigned long arg2, unsigned long arg3,
 389                             unsigned long arg4)
 390 {
 391         if (smp_processors_ready) {
 392                 register int high = NR_CPUS - 1;
 393                 unsigned long flags;
 394
 395                 spin_lock_irqsave(&cross_call_lock, flags);
 396
 397                 {
 398                         /* If you make changes here, make sure gcc generates proper code... */
 399                         register smpfunc_t f asm("i0") = func;
 400                         register unsigned long a1 asm("i1") = arg1;
 401                         register unsigned long a2 asm("i2") = arg2;
 402                         register unsigned long a3 asm("i3") = arg3;
 403                         register unsigned long a4 asm("i4") = arg4;
 404                         register unsigned long a5 asm("i5") = 0;
 405
 406                         __asm__ __volatile__("std %0, [%6]\n\t"
 407                                              "std %2, [%6 + 8]\n\t"
 408                                              "std %4, [%6 + 16]\n\t" : :
 409                                              "r"(f), "r"(a1), "r"(a2), "r"(a3),
 410                                              "r"(a4), "r"(a5),
 411                                              "r"(&ccall_info.func));
 412                 }
 413
 414                 /* Init receive/complete mapping, plus fire the IPI's off. */
 415                 {
 416                         register int i;
 417
 418                         cpumask_clear_cpu(smp_processor_id(), &mask);
 419                         cpumask_and(&mask, cpu_online_mask, &mask);
 420                         for (i = 0; i <= high; i++) {
 421                                 if (cpumask_test_cpu(i, &mask)) {
 422                                         ccall_info.processors_in[i] = 0;
 423                                         ccall_info.processors_out[i] = 0;
 424                                         leon_send_ipi(i, LEON3_IRQ_CROSS_CALL);
 425
 426                                 }
 427                         }
 428                 }
 429
 430                 {
 431                         register int i;
 432
 433                         i = 0;
 434                         do {
 435                                 if (!cpumask_test_cpu(i, &mask))
 436                                         continue;
 437
 438                                 while (!ccall_info.processors_in[i])
 439                                         barrier();
 440                         } while (++i <= high);
 441
 442                         i = 0;
 443                         do {
 444                                 if (!cpumask_test_cpu(i, &mask))
 445                                         continue;
 446
 447                                 while (!ccall_info.processors_out[i])
 448                                         barrier();
 449                         } while (++i <= high);
 450                 }
 451
 452                 spin_unlock_irqrestore(&cross_call_lock, flags);
 453         }
 454 }
 455
 456 /* Running cross calls. */
 457 void leon_cross_call_irq(void)
 458 {
 459         int i = smp_processor_id();
 460
 461         ccall_info.processors_in[i] = 1;
 462         ccall_info.func(ccall_info.arg1, ccall_info.arg2, ccall_info.arg3,
 463                         ccall_info.arg4, ccall_info.arg5);
 464         ccall_info.processors_out[i] = 1;
 465 }
 466
 467 static const struct sparc32_ipi_ops leon_ipi_ops = {
 468         .cross_call = leon_cross_call,
 469         .resched    = leon_ipi_resched,
 470         .single     = leon_ipi_single,
 471         .mask_one   = leon_ipi_mask_one,
 472 };
 473
 474 void __init leon_init_smp(void)
 475 {
 476         /* Patch ipi15 trap table */
 477         t_nmi[1] = t_nmi[1] + (linux_trap_ipi15_leon - linux_trap_ipi15_sun4m);
 478
 479         sparc32_ipi_ops = &leon_ipi_ops;
 480 }