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/pgalloc.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         mmgrab(&init_mm);
  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 static 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 int leon_smp_nrcpus(void)
 152 {
 153         int nrcpu =
 154             ((LEON3_BYPASS_LOAD_PA(&(leon3_irqctrl_regs->mpstatus)) >>
 155               LEON3_IRQMPSTATUS_CPUNR) & 0xf) + 1;
 156         return nrcpu;
 157 }
 158
 159 void __init leon_boot_cpus(void)
 160 {
 161         int nrcpu = leon_smp_nrcpus();
 162         int me = smp_processor_id();
 163
 164         /* Setup IPI */
 165         leon_ipi_init();
 166
 167         printk(KERN_INFO "%d:(%d:%d) cpus mpirq at 0x%x\n", (unsigned int)me,
 168                (unsigned int)nrcpu, (unsigned int)NR_CPUS,
 169                (unsigned int)&(leon3_irqctrl_regs->mpstatus));
 170
 171         leon_enable_irq_cpu(LEON3_IRQ_CROSS_CALL, me);
 172         leon_enable_irq_cpu(LEON3_IRQ_TICKER, me);
 173         leon_enable_irq_cpu(leon_ipi_irq, me);
 174
 175         leon_smp_setbroadcast(1 << LEON3_IRQ_TICKER);
 176
 177         leon_configure_cache_smp();
 178         local_ops->cache_all();
 179
 180 }
 181
 182 int leon_boot_one_cpu(int i, struct task_struct *idle)
 183 {
 184         int timeout;
 185
 186         current_set[i] = task_thread_info(idle);
 187
 188         /* See trampoline.S:leon_smp_cpu_startup for details...
 189          * Initialize the contexts table
 190          * Since the call to prom_startcpu() trashes the structure,
 191          * we need to re-initialize it for each cpu
 192          */
 193         smp_penguin_ctable.which_io = 0;
 194         smp_penguin_ctable.phys_addr = (unsigned int)srmmu_ctx_table_phys;
 195         smp_penguin_ctable.reg_size = 0;
 196
 197         /* whirrr, whirrr, whirrrrrrrrr... */
 198         printk(KERN_INFO "Starting CPU %d : (irqmp: 0x%x)\n", (unsigned int)i,
 199                (unsigned int)&leon3_irqctrl_regs->mpstatus);
 200         local_ops->cache_all();
 201
 202         /* Make sure all IRQs are of from the start for this new CPU */
 203         LEON_BYPASS_STORE_PA(&leon3_irqctrl_regs->mask[i], 0);
 204
 205         /* Wake one CPU */
 206         LEON_BYPASS_STORE_PA(&(leon3_irqctrl_regs->mpstatus), 1 << i);
 207
 208         /* wheee... it's going... */
 209         for (timeout = 0; timeout < 10000; timeout++) {
 210                 if (cpu_callin_map[i])
 211                         break;
 212                 udelay(200);
 213         }
 214         printk(KERN_INFO "Started CPU %d\n", (unsigned int)i);
 215
 216         if (!(cpu_callin_map[i])) {
 217                 printk(KERN_ERR "Processor %d is stuck.\n", i);
 218                 return -ENODEV;
 219         } else {
 220                 leon_enable_irq_cpu(LEON3_IRQ_CROSS_CALL, i);
 221                 leon_enable_irq_cpu(LEON3_IRQ_TICKER, i);
 222                 leon_enable_irq_cpu(leon_ipi_irq, i);
 223         }
 224
 225         local_ops->cache_all();
 226         return 0;
 227 }
 228
 229 void __init leon_smp_done(void)
 230 {
 231
 232         int i, first;
 233         int *prev;
 234
 235         /* setup cpu list for irq rotation */
 236         first = 0;
 237         prev = &first;
 238         for (i = 0; i < NR_CPUS; i++) {
 239                 if (cpu_online(i)) {
 240                         *prev = i;
 241                         prev = &cpu_data(i).next;
 242                 }
 243         }
 244         *prev = first;
 245         local_ops->cache_all();
 246
 247         /* Free unneeded trap tables */
 248         if (!cpu_present(1)) {
 249                 free_reserved_page(virt_to_page(&trapbase_cpu1));
 250         }
 251         if (!cpu_present(2)) {
 252                 free_reserved_page(virt_to_page(&trapbase_cpu2));
 253         }
 254         if (!cpu_present(3)) {
 255                 free_reserved_page(virt_to_page(&trapbase_cpu3));
 256         }
 257         /* Ok, they are spinning and ready to go. */
 258         smp_processors_ready = 1;
 259
 260 }
 261
 262 struct leon_ipi_work {
 263         int single;
 264         int msk;
 265         int resched;
 266 };
 267
 268 static DEFINE_PER_CPU_SHARED_ALIGNED(struct leon_ipi_work, leon_ipi_work);
 269
 270 /* Initialize IPIs on the LEON, in order to save IRQ resources only one IRQ
 271  * is used for all three types of IPIs.
 272  */
 273 static void __init leon_ipi_init(void)
 274 {
 275         int cpu, len;
 276         struct leon_ipi_work *work;
 277         struct property *pp;
 278         struct device_node *rootnp;
 279         struct tt_entry *trap_table;
 280         unsigned long flags;
 281
 282         /* Find IPI IRQ or stick with default value */
 283         rootnp = of_find_node_by_path("/ambapp0");
 284         if (rootnp) {
 285                 pp = of_find_property(rootnp, "ipi_num", &len);
 286                 if (pp && (*(int *)pp->value))
 287                         leon_ipi_irq = *(int *)pp->value;
 288         }
 289         printk(KERN_INFO "leon: SMP IPIs at IRQ %d\n", leon_ipi_irq);
 290
 291         /* Adjust so that we jump directly to smpleon_ipi */
 292         local_irq_save(flags);
 293         trap_table = &sparc_ttable[SP_TRAP_IRQ1 + (leon_ipi_irq - 1)];
 294         trap_table->inst_three += smpleon_ipi - real_irq_entry;
 295         local_ops->cache_all();
 296         local_irq_restore(flags);
 297
 298         for_each_possible_cpu(cpu) {
 299                 work = &per_cpu(leon_ipi_work, cpu);
 300                 work->single = work->msk = work->resched = 0;
 301         }
 302 }
 303
 304 static void leon_send_ipi(int cpu, int level)
 305 {
 306         unsigned long mask;
 307         mask = leon_get_irqmask(level);
 308         LEON3_BYPASS_STORE_PA(&leon3_irqctrl_regs->force[cpu], mask);
 309 }
 310
 311 static void leon_ipi_single(int cpu)
 312 {
 313         struct leon_ipi_work *work = &per_cpu(leon_ipi_work, cpu);
 314
 315         /* Mark work */
 316         work->single = 1;
 317
 318         /* Generate IRQ on the CPU */
 319         leon_send_ipi(cpu, leon_ipi_irq);
 320 }
 321
 322 static void leon_ipi_mask_one(int cpu)
 323 {
 324         struct leon_ipi_work *work = &per_cpu(leon_ipi_work, cpu);
 325
 326         /* Mark work */
 327         work->msk = 1;
 328
 329         /* Generate IRQ on the CPU */
 330         leon_send_ipi(cpu, leon_ipi_irq);
 331 }
 332
 333 static void leon_ipi_resched(int cpu)
 334 {
 335         struct leon_ipi_work *work = &per_cpu(leon_ipi_work, cpu);
 336
 337         /* Mark work */
 338         work->resched = 1;
 339
 340         /* Generate IRQ on the CPU (any IRQ will cause resched) */
 341         leon_send_ipi(cpu, leon_ipi_irq);
 342 }
 343
 344 void leonsmp_ipi_interrupt(void)
 345 {
 346         struct leon_ipi_work *work = this_cpu_ptr(&leon_ipi_work);
 347
 348         if (work->single) {
 349                 work->single = 0;
 350                 smp_call_function_single_interrupt();
 351         }
 352         if (work->msk) {
 353                 work->msk = 0;
 354                 smp_call_function_interrupt();
 355         }
 356         if (work->resched) {
 357                 work->resched = 0;
 358                 smp_resched_interrupt();
 359         }
 360 }
 361
 362 static struct smp_funcall {
 363         smpfunc_t func;
 364         unsigned long arg1;
 365         unsigned long arg2;
 366         unsigned long arg3;
 367         unsigned long arg4;
 368         unsigned long arg5;
 369         unsigned long processors_in[NR_CPUS];   /* Set when ipi entered. */
 370         unsigned long processors_out[NR_CPUS];  /* Set when ipi exited. */
 371 } ccall_info __attribute__((aligned(8)));
 372
 373 static DEFINE_SPINLOCK(cross_call_lock);
 374
 375 /* Cross calls must be serialized, at least currently. */
 376 static void leon_cross_call(smpfunc_t func, cpumask_t mask, unsigned long arg1,
 377                             unsigned long arg2, unsigned long arg3,
 378                             unsigned long arg4)
 379 {
 380         if (smp_processors_ready) {
 381                 register int high = NR_CPUS - 1;
 382                 unsigned long flags;
 383
 384                 spin_lock_irqsave(&cross_call_lock, flags);
 385
 386                 {
 387                         /* If you make changes here, make sure gcc generates proper code... */
 388                         register smpfunc_t f asm("i0") = func;
 389                         register unsigned long a1 asm("i1") = arg1;
 390                         register unsigned long a2 asm("i2") = arg2;
 391                         register unsigned long a3 asm("i3") = arg3;
 392                         register unsigned long a4 asm("i4") = arg4;
 393                         register unsigned long a5 asm("i5") = 0;
 394
 395                         __asm__ __volatile__("std %0, [%6]\n\t"
 396                                              "std %2, [%6 + 8]\n\t"
 397                                              "std %4, [%6 + 16]\n\t" : :
 398                                              "r"(f), "r"(a1), "r"(a2), "r"(a3),
 399                                              "r"(a4), "r"(a5),
 400                                              "r"(&ccall_info.func));
 401                 }
 402
 403                 /* Init receive/complete mapping, plus fire the IPI's off. */
 404                 {
 405                         register int i;
 406
 407                         cpumask_clear_cpu(smp_processor_id(), &mask);
 408                         cpumask_and(&mask, cpu_online_mask, &mask);
 409                         for (i = 0; i <= high; i++) {
 410                                 if (cpumask_test_cpu(i, &mask)) {
 411                                         ccall_info.processors_in[i] = 0;
 412                                         ccall_info.processors_out[i] = 0;
 413                                         leon_send_ipi(i, LEON3_IRQ_CROSS_CALL);
 414
 415                                 }
 416                         }
 417                 }
 418
 419                 {
 420                         register int i;
 421
 422                         i = 0;
 423                         do {
 424                                 if (!cpumask_test_cpu(i, &mask))
 425                                         continue;
 426
 427                                 while (!ccall_info.processors_in[i])
 428                                         barrier();
 429                         } while (++i <= high);
 430
 431                         i = 0;
 432                         do {
 433                                 if (!cpumask_test_cpu(i, &mask))
 434                                         continue;
 435
 436                                 while (!ccall_info.processors_out[i])
 437                                         barrier();
 438                         } while (++i <= high);
 439                 }
 440
 441                 spin_unlock_irqrestore(&cross_call_lock, flags);
 442         }
 443 }
 444
 445 /* Running cross calls. */
 446 void leon_cross_call_irq(void)
 447 {
 448         int i = smp_processor_id();
 449
 450         ccall_info.processors_in[i] = 1;
 451         ccall_info.func(ccall_info.arg1, ccall_info.arg2, ccall_info.arg3,
 452                         ccall_info.arg4, ccall_info.arg5);
 453         ccall_info.processors_out[i] = 1;
 454 }
 455
 456 static const struct sparc32_ipi_ops leon_ipi_ops = {
 457         .cross_call = leon_cross_call,
 458         .resched    = leon_ipi_resched,
 459         .single     = leon_ipi_single,
 460         .mask_one   = leon_ipi_mask_one,
 461 };
 462
 463 void __init leon_init_smp(void)
 464 {
 465         /* Patch ipi15 trap table */
 466         t_nmi[1] = t_nmi[1] + (linux_trap_ipi15_leon - linux_trap_ipi15_sun4m);
 467
 468         sparc32_ipi_ops = &leon_ipi_ops;
 469 }