arch/sparc/kernel/leon_smp.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* leon_smp.c: Sparc-Leon SMP support.
   3  *
   4  * based on sun4m_smp.c
   5  * Copyright (C) 1996 David S. Miller (davem@caip.rutgers.edu)
   6  * Copyright (C) 2009 Daniel Hellstrom (daniel@gaisler.com) Aeroflex Gaisler AB
   7  * Copyright (C) 2009 Konrad Eisele (konrad@gaisler.com) Aeroflex Gaisler AB
   8  */
   9
  10 #include <asm/head.h>
  11
  12 #include <linux/kernel.h>
  13 #include <linux/sched/mm.h>
  14 #include <linux/threads.h>
  15 #include <linux/smp.h>
  16 #include <linux/interrupt.h>
  17 #include <linux/kernel_stat.h>
  18 #include <linux/of.h>
  19 #include <linux/init.h>
  20 #include <linux/spinlock.h>
  21 #include <linux/mm.h>
  22 #include <linux/swap.h>
  23 #include <linux/profile.h>
  24 #include <linux/pm.h>
  25 #include <linux/delay.h>
  26 #include <linux/gfp.h>
  27 #include <linux/cpu.h>
  28 #include <linux/clockchips.h>
  29
  30 #include <asm/cacheflush.h>
  31 #include <asm/tlbflush.h>
  32
  33 #include <asm/ptrace.h>
  34 #include <linux/atomic.h>
  35 #include <asm/irq_regs.h>
  36 #include <asm/traps.h>
  37
  38 #include <asm/delay.h>
  39 #include <asm/irq.h>
  40 #include <asm/page.h>
  41 #include <asm/oplib.h>
  42 #include <asm/cpudata.h>
  43 #include <asm/asi.h>
  44 #include <asm/leon.h>
  45 #include <asm/leon_amba.h>
  46 #include <asm/timer.h>
  47
  48 #include "kernel.h"
  49
  50 #include "irq.h"
  51
  52 extern ctxd_t *srmmu_ctx_table_phys;
  53 static int smp_processors_ready;
  54 extern volatile unsigned long cpu_callin_map[NR_CPUS];
  55 extern cpumask_t smp_commenced_mask;
  56 void leon_configure_cache_smp(void);
  57 static void leon_ipi_init(void);
  58
  59 /* IRQ number of LEON IPIs */
  60 int leon_ipi_irq = LEON3_IRQ_IPI_DEFAULT;
  61
  62 static inline unsigned long do_swap(volatile unsigned long *ptr,
  63                                     unsigned long val)
  64 {
  65         __asm__ __volatile__("swapa [%2] %3, %0\n\t" : "=&r"(val)
  66                              : "0"(val), "r"(ptr), "i"(ASI_LEON_DCACHE_MISS)
  67                              : "memory");
  68         return val;
  69 }
  70
  71 void leon_cpu_pre_starting(void *arg)
  72 {
  73         leon_configure_cache_smp();
  74 }
  75
  76 void leon_cpu_pre_online(void *arg)
  77 {
  78         int cpuid = hard_smp_processor_id();
  79
  80         /* Allow master to continue. The master will then give us the
  81          * go-ahead by setting the smp_commenced_mask and will wait without
  82          * timeouts until our setup is completed fully (signified by
  83          * our bit being set in the cpu_online_mask).
  84          */
  85         do_swap(&cpu_callin_map[cpuid], 1);
  86
  87         local_ops->cache_all();
  88         local_ops->tlb_all();
  89
  90         /* Fix idle thread fields. */
  91         __asm__ __volatile__("ld [%0], %%g6\n\t" : : "r"(&current_set[cpuid])
  92                              : "memory" /* paranoid */);
  93
  94         /* Attach to the address space of init_task. */
  95         mmgrab(&init_mm);
  96         current->active_mm = &init_mm;
  97
  98         while (!cpumask_test_cpu(cpuid, &smp_commenced_mask))
  99                 mb();
 100 }
 101
 102 /*
 103  *      Cycle through the processors asking the PROM to start each one.
 104  */
 105
 106 extern struct linux_prom_registers smp_penguin_ctable;
 107
 108 void leon_configure_cache_smp(void)
 109 {
 110         unsigned long cfg = sparc_leon3_get_dcachecfg();
 111         int me = smp_processor_id();
 112
 113         if (ASI_LEON3_SYSCTRL_CFG_SSIZE(cfg) > 4) {
 114                 printk(KERN_INFO "Note: SMP with snooping only works on 4k cache, found %dk(0x%x) on cpu %d, disabling caches\n",
 115                      (unsigned int)ASI_LEON3_SYSCTRL_CFG_SSIZE(cfg),
 116                      (unsigned int)cfg, (unsigned int)me);
 117                 sparc_leon3_disable_cache();
 118         } else {
 119                 if (cfg & ASI_LEON3_SYSCTRL_CFG_SNOOPING) {
 120                         sparc_leon3_enable_snooping();
 121                 } else {
 122                         printk(KERN_INFO "Note: You have to enable snooping in the vhdl model cpu %d, disabling caches\n",
 123                              me);
 124                         sparc_leon3_disable_cache();
 125                 }
 126         }
 127
 128         local_ops->cache_all();
 129         local_ops->tlb_all();
 130 }
 131
 132 static void leon_smp_setbroadcast(unsigned int mask)
 133 {
 134         int broadcast =
 135             ((LEON3_BYPASS_LOAD_PA(&(leon3_irqctrl_regs->mpstatus)) >>
 136               LEON3_IRQMPSTATUS_BROADCAST) & 1);
 137         if (!broadcast) {
 138                 prom_printf("######## !!!! The irqmp-ctrl must have broadcast enabled, smp wont work !!!!! ####### nr cpus: %d\n",
 139                      leon_smp_nrcpus());
 140                 if (leon_smp_nrcpus() > 1) {
 141                         BUG();
 142                 } else {
 143                         prom_printf("continue anyway\n");
 144                         return;
 145                 }
 146         }
 147         LEON_BYPASS_STORE_PA(&(leon3_irqctrl_regs->mpbroadcast), mask);
 148 }
 149
 150 int leon_smp_nrcpus(void)
 151 {
 152         int nrcpu =
 153             ((LEON3_BYPASS_LOAD_PA(&(leon3_irqctrl_regs->mpstatus)) >>
 154               LEON3_IRQMPSTATUS_CPUNR) & 0xf) + 1;
 155         return nrcpu;
 156 }
 157
 158 void __init leon_boot_cpus(void)
 159 {
 160         int nrcpu = leon_smp_nrcpus();
 161         int me = smp_processor_id();
 162
 163         /* Setup IPI */
 164         leon_ipi_init();
 165
 166         printk(KERN_INFO "%d:(%d:%d) cpus mpirq at 0x%x\n", (unsigned int)me,
 167                (unsigned int)nrcpu, (unsigned int)NR_CPUS,
 168                (unsigned int)&(leon3_irqctrl_regs->mpstatus));
 169
 170         leon_enable_irq_cpu(LEON3_IRQ_CROSS_CALL, me);
 171         leon_enable_irq_cpu(LEON3_IRQ_TICKER, me);
 172         leon_enable_irq_cpu(leon_ipi_irq, me);
 173
 174         leon_smp_setbroadcast(1 << LEON3_IRQ_TICKER);
 175
 176         leon_configure_cache_smp();
 177         local_ops->cache_all();
 178
 179 }
 180
 181 int leon_boot_one_cpu(int i, struct task_struct *idle)
 182 {
 183         int timeout;
 184
 185         current_set[i] = task_thread_info(idle);
 186
 187         /* See trampoline.S:leon_smp_cpu_startup for details...
 188          * Initialize the contexts table
 189          * Since the call to prom_startcpu() trashes the structure,
 190          * we need to re-initialize it for each cpu
 191          */
 192         smp_penguin_ctable.which_io = 0;
 193         smp_penguin_ctable.phys_addr = (unsigned int)srmmu_ctx_table_phys;
 194         smp_penguin_ctable.reg_size = 0;
 195
 196         /* whirrr, whirrr, whirrrrrrrrr... */
 197         printk(KERN_INFO "Starting CPU %d : (irqmp: 0x%x)\n", (unsigned int)i,
 198                (unsigned int)&leon3_irqctrl_regs->mpstatus);
 199         local_ops->cache_all();
 200
 201         /* Make sure all IRQs are of from the start for this new CPU */
 202         LEON_BYPASS_STORE_PA(&leon3_irqctrl_regs->mask[i], 0);
 203
 204         /* Wake one CPU */
 205         LEON_BYPASS_STORE_PA(&(leon3_irqctrl_regs->mpstatus), 1 << i);
 206
 207         /* wheee... it's going... */
 208         for (timeout = 0; timeout < 10000; timeout++) {
 209                 if (cpu_callin_map[i])
 210                         break;
 211                 udelay(200);
 212         }
 213         printk(KERN_INFO "Started CPU %d\n", (unsigned int)i);
 214
 215         if (!(cpu_callin_map[i])) {
 216                 printk(KERN_ERR "Processor %d is stuck.\n", i);
 217                 return -ENODEV;
 218         } else {
 219                 leon_enable_irq_cpu(LEON3_IRQ_CROSS_CALL, i);
 220                 leon_enable_irq_cpu(LEON3_IRQ_TICKER, i);
 221                 leon_enable_irq_cpu(leon_ipi_irq, i);
 222         }
 223
 224         local_ops->cache_all();
 225         return 0;
 226 }
 227
 228 void __init leon_smp_done(void)
 229 {
 230
 231         int i, first;
 232         int *prev;
 233
 234         /* setup cpu list for irq rotation */
 235         first = 0;
 236         prev = &first;
 237         for (i = 0; i < NR_CPUS; i++) {
 238                 if (cpu_online(i)) {
 239                         *prev = i;
 240                         prev = &cpu_data(i).next;
 241                 }
 242         }
 243         *prev = first;
 244         local_ops->cache_all();
 245
 246         /* Free unneeded trap tables */
 247         if (!cpu_present(1)) {
 248                 free_reserved_page(virt_to_page(&trapbase_cpu1));
 249         }
 250         if (!cpu_present(2)) {
 251                 free_reserved_page(virt_to_page(&trapbase_cpu2));
 252         }
 253         if (!cpu_present(3)) {
 254                 free_reserved_page(virt_to_page(&trapbase_cpu3));
 255         }
 256         /* Ok, they are spinning and ready to go. */
 257         smp_processors_ready = 1;
 258
 259 }
 260
 261 struct leon_ipi_work {
 262         int single;
 263         int msk;
 264         int resched;
 265 };
 266
 267 static DEFINE_PER_CPU_SHARED_ALIGNED(struct leon_ipi_work, leon_ipi_work);
 268
 269 /* Initialize IPIs on the LEON, in order to save IRQ resources only one IRQ
 270  * is used for all three types of IPIs.
 271  */
 272 static void __init leon_ipi_init(void)
 273 {
 274         int cpu, len;
 275         struct leon_ipi_work *work;
 276         struct property *pp;
 277         struct device_node *rootnp;
 278         struct tt_entry *trap_table;
 279         unsigned long flags;
 280
 281         /* Find IPI IRQ or stick with default value */
 282         rootnp = of_find_node_by_path("/ambapp0");
 283         if (rootnp) {
 284                 pp = of_find_property(rootnp, "ipi_num", &len);
 285                 if (pp && (*(int *)pp->value))
 286                         leon_ipi_irq = *(int *)pp->value;
 287         }
 288         printk(KERN_INFO "leon: SMP IPIs at IRQ %d\n", leon_ipi_irq);
 289
 290         /* Adjust so that we jump directly to smpleon_ipi */
 291         local_irq_save(flags);
 292         trap_table = &sparc_ttable[SP_TRAP_IRQ1 + (leon_ipi_irq - 1)];
 293         trap_table->inst_three += smpleon_ipi - real_irq_entry;
 294         local_ops->cache_all();
 295         local_irq_restore(flags);
 296
 297         for_each_possible_cpu(cpu) {
 298                 work = &per_cpu(leon_ipi_work, cpu);
 299                 work->single = work->msk = work->resched = 0;
 300         }
 301 }
 302
 303 static void leon_send_ipi(int cpu, int level)
 304 {
 305         unsigned long mask;
 306         mask = leon_get_irqmask(level);
 307         LEON3_BYPASS_STORE_PA(&leon3_irqctrl_regs->force[cpu], mask);
 308 }
 309
 310 static void leon_ipi_single(int cpu)
 311 {
 312         struct leon_ipi_work *work = &per_cpu(leon_ipi_work, cpu);
 313
 314         /* Mark work */
 315         work->single = 1;
 316
 317         /* Generate IRQ on the CPU */
 318         leon_send_ipi(cpu, leon_ipi_irq);
 319 }
 320
 321 static void leon_ipi_mask_one(int cpu)
 322 {
 323         struct leon_ipi_work *work = &per_cpu(leon_ipi_work, cpu);
 324
 325         /* Mark work */
 326         work->msk = 1;
 327
 328         /* Generate IRQ on the CPU */
 329         leon_send_ipi(cpu, leon_ipi_irq);
 330 }
 331
 332 static void leon_ipi_resched(int cpu)
 333 {
 334         struct leon_ipi_work *work = &per_cpu(leon_ipi_work, cpu);
 335
 336         /* Mark work */
 337         work->resched = 1;
 338
 339         /* Generate IRQ on the CPU (any IRQ will cause resched) */
 340         leon_send_ipi(cpu, leon_ipi_irq);
 341 }
 342
 343 void leonsmp_ipi_interrupt(void)
 344 {
 345         struct leon_ipi_work *work = this_cpu_ptr(&leon_ipi_work);
 346
 347         if (work->single) {
 348                 work->single = 0;
 349                 smp_call_function_single_interrupt();
 350         }
 351         if (work->msk) {
 352                 work->msk = 0;
 353                 smp_call_function_interrupt();
 354         }
 355         if (work->resched) {
 356                 work->resched = 0;
 357                 smp_resched_interrupt();
 358         }
 359 }
 360
 361 static struct smp_funcall {
 362         smpfunc_t func;
 363         unsigned long arg1;
 364         unsigned long arg2;
 365         unsigned long arg3;
 366         unsigned long arg4;
 367         unsigned long arg5;
 368         unsigned long processors_in[NR_CPUS];   /* Set when ipi entered. */
 369         unsigned long processors_out[NR_CPUS];  /* Set when ipi exited. */
 370 } ccall_info __attribute__((aligned(8)));
 371
 372 static DEFINE_SPINLOCK(cross_call_lock);
 373
 374 /* Cross calls must be serialized, at least currently. */
 375 static void leon_cross_call(smpfunc_t func, cpumask_t mask, unsigned long arg1,
 376                             unsigned long arg2, unsigned long arg3,
 377                             unsigned long arg4)
 378 {
 379         if (smp_processors_ready) {
 380                 register int high = NR_CPUS - 1;
 381                 unsigned long flags;
 382
 383                 spin_lock_irqsave(&cross_call_lock, flags);
 384
 385                 {
 386                         /* If you make changes here, make sure gcc generates proper code... */
 387                         register smpfunc_t f asm("i0") = func;
 388                         register unsigned long a1 asm("i1") = arg1;
 389                         register unsigned long a2 asm("i2") = arg2;
 390                         register unsigned long a3 asm("i3") = arg3;
 391                         register unsigned long a4 asm("i4") = arg4;
 392                         register unsigned long a5 asm("i5") = 0;
 393
 394                         __asm__ __volatile__("std %0, [%6]\n\t"
 395                                              "std %2, [%6 + 8]\n\t"
 396                                              "std %4, [%6 + 16]\n\t" : :
 397                                              "r"(f), "r"(a1), "r"(a2), "r"(a3),
 398                                              "r"(a4), "r"(a5),
 399                                              "r"(&ccall_info.func));
 400                 }
 401
 402                 /* Init receive/complete mapping, plus fire the IPI's off. */
 403                 {
 404                         register int i;
 405
 406                         cpumask_clear_cpu(smp_processor_id(), &mask);
 407                         cpumask_and(&mask, cpu_online_mask, &mask);
 408                         for (i = 0; i <= high; i++) {
 409                                 if (cpumask_test_cpu(i, &mask)) {
 410                                         ccall_info.processors_in[i] = 0;
 411                                         ccall_info.processors_out[i] = 0;
 412                                         leon_send_ipi(i, LEON3_IRQ_CROSS_CALL);
 413
 414                                 }
 415                         }
 416                 }
 417
 418                 {
 419                         register int i;
 420
 421                         i = 0;
 422                         do {
 423                                 if (!cpumask_test_cpu(i, &mask))
 424                                         continue;
 425
 426                                 while (!ccall_info.processors_in[i])
 427                                         barrier();
 428                         } while (++i <= high);
 429
 430                         i = 0;
 431                         do {
 432                                 if (!cpumask_test_cpu(i, &mask))
 433                                         continue;
 434
 435                                 while (!ccall_info.processors_out[i])
 436                                         barrier();
 437                         } while (++i <= high);
 438                 }
 439
 440                 spin_unlock_irqrestore(&cross_call_lock, flags);
 441         }
 442 }
 443
 444 /* Running cross calls. */
 445 void leon_cross_call_irq(void)
 446 {
 447         int i = smp_processor_id();
 448
 449         ccall_info.processors_in[i] = 1;
 450         ccall_info.func(ccall_info.arg1, ccall_info.arg2, ccall_info.arg3,
 451                         ccall_info.arg4, ccall_info.arg5);
 452         ccall_info.processors_out[i] = 1;
 453 }
 454
 455 static const struct sparc32_ipi_ops leon_ipi_ops = {
 456         .cross_call = leon_cross_call,
 457         .resched    = leon_ipi_resched,
 458         .single     = leon_ipi_single,
 459         .mask_one   = leon_ipi_mask_one,
 460 };
 461
 462 void __init leon_init_smp(void)
 463 {
 464         /* Patch ipi15 trap table */
 465         t_nmi[1] = t_nmi[1] + (linux_trap_ipi15_leon - linux_trap_ipi15_sun4m);
 466
 467         sparc32_ipi_ops = &leon_ipi_ops;
 468 }