linux/arch/sparc/kernel/leon_smp.c
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   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
  53extern ctxd_t *srmmu_ctx_table_phys;
  54static int smp_processors_ready;
  55extern volatile unsigned long cpu_callin_map[NR_CPUS];
  56extern cpumask_t smp_commenced_mask;
  57void leon_configure_cache_smp(void);
  58static void leon_ipi_init(void);
  59
  60/* IRQ number of LEON IPIs */
  61int leon_ipi_irq = LEON3_IRQ_IPI_DEFAULT;
  62
  63static 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
  72void leon_cpu_pre_starting(void *arg)
  73{
  74        leon_configure_cache_smp();
  75}
  76
  77void 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
 107extern struct linux_prom_registers smp_penguin_ctable;
 108
 109void 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
 133static 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
 151int 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
 159void __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
 182int 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
 229void __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
 262struct leon_ipi_work {
 263        int single;
 264        int msk;
 265        int resched;
 266};
 267
 268static 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 */
 273static 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
 304static 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
 311static 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
 322static 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
 333static 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
 344void leonsmp_ipi_interrupt(void)
 345{
 346        struct leon_ipi_work *work = &__get_cpu_var(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
 362static 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;
 372
 373static DEFINE_SPINLOCK(cross_call_lock);
 374
 375/* Cross calls must be serialized, at least currently. */
 376static 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. */
 446void 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
 456static 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
 463void __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}
 470