arch/mips/cavium-octeon/smp.c

   1 /*
   2  * This file is subject to the terms and conditions of the GNU General Public
   3  * License.  See the file "COPYING" in the main directory of this archive
   4  * for more details.
   5  *
   6  * Copyright (C) 2004-2008, 2009, 2010 Cavium Networks
   7  */
   8 #include <linux/cpu.h>
   9 #include <linux/init.h>
  10 #include <linux/delay.h>
  11 #include <linux/smp.h>
  12 #include <linux/interrupt.h>
  13 #include <linux/kernel_stat.h>
  14 #include <linux/sched.h>
  15 #include <linux/module.h>
  16
  17 #include <asm/mmu_context.h>
  18 #include <asm/system.h>
  19 #include <asm/time.h>
  20
  21 #include <asm/octeon/octeon.h>
  22
  23 #include "octeon_boot.h"
  24
  25 volatile unsigned long octeon_processor_boot = 0xff;
  26 volatile unsigned long octeon_processor_sp;
  27 volatile unsigned long octeon_processor_gp;
  28
  29 #ifdef CONFIG_HOTPLUG_CPU
  30 uint64_t octeon_bootloader_entry_addr;
  31 EXPORT_SYMBOL(octeon_bootloader_entry_addr);
  32 #endif
  33
  34 static irqreturn_t mailbox_interrupt(int irq, void *dev_id)
  35 {
  36         const int coreid = cvmx_get_core_num();
  37         uint64_t action;
  38
  39         /* Load the mailbox register to figure out what we're supposed to do */
  40         action = cvmx_read_csr(CVMX_CIU_MBOX_CLRX(coreid)) & 0xffff;
  41
  42         /* Clear the mailbox to clear the interrupt */
  43         cvmx_write_csr(CVMX_CIU_MBOX_CLRX(coreid), action);
  44
  45         if (action & SMP_CALL_FUNCTION)
  46                 smp_call_function_interrupt();
  47         if (action & SMP_RESCHEDULE_YOURSELF)
  48                 scheduler_ipi();
  49
  50         /* Check if we've been told to flush the icache */
  51         if (action & SMP_ICACHE_FLUSH)
  52                 asm volatile ("synci 0($0)\n");
  53         return IRQ_HANDLED;
  54 }
  55
  56 /**
  57  * Cause the function described by call_data to be executed on the passed
  58  * cpu.  When the function has finished, increment the finished field of
  59  * call_data.
  60  */
  61 void octeon_send_ipi_single(int cpu, unsigned int action)
  62 {
  63         int coreid = cpu_logical_map(cpu);
  64         /*
  65         pr_info("SMP: Mailbox send cpu=%d, coreid=%d, action=%u\n", cpu,
  66                coreid, action);
  67         */
  68         cvmx_write_csr(CVMX_CIU_MBOX_SETX(coreid), action);
  69 }
  70
  71 static inline void octeon_send_ipi_mask(const struct cpumask *mask,
  72                                         unsigned int action)
  73 {
  74         unsigned int i;
  75
  76         for_each_cpu_mask(i, *mask)
  77                 octeon_send_ipi_single(i, action);
  78 }
  79
  80 /**
  81  * Detect available CPUs, populate cpu_possible_map
  82  */
  83 static void octeon_smp_hotplug_setup(void)
  84 {
  85 #ifdef CONFIG_HOTPLUG_CPU
  86         struct linux_app_boot_info *labi;
  87
  88         labi = (struct linux_app_boot_info *)PHYS_TO_XKSEG_CACHED(LABI_ADDR_IN_BOOTLOADER);
  89         if (labi->labi_signature != LABI_SIGNATURE)
  90                 panic("The bootloader version on this board is incorrect.");
  91
  92         octeon_bootloader_entry_addr = labi->InitTLBStart_addr;
  93 #endif
  94 }
  95
  96 static void octeon_smp_setup(void)
  97 {
  98         const int coreid = cvmx_get_core_num();
  99         int cpus;
 100         int id;
 101         int core_mask = octeon_get_boot_coremask();
 102 #ifdef CONFIG_HOTPLUG_CPU
 103         unsigned int num_cores = cvmx_octeon_num_cores();
 104 #endif
 105
 106         /* The present CPUs are initially just the boot cpu (CPU 0). */
 107         for (id = 0; id < NR_CPUS; id++) {
 108                 set_cpu_possible(id, id == 0);
 109                 set_cpu_present(id, id == 0);
 110         }
 111
 112         __cpu_number_map[coreid] = 0;
 113         __cpu_logical_map[0] = coreid;
 114
 115         /* The present CPUs get the lowest CPU numbers. */
 116         cpus = 1;
 117         for (id = 0; id < NR_CPUS; id++) {
 118                 if ((id != coreid) && (core_mask & (1 << id))) {
 119                         set_cpu_possible(cpus, true);
 120                         set_cpu_present(cpus, true);
 121                         __cpu_number_map[id] = cpus;
 122                         __cpu_logical_map[cpus] = id;
 123                         cpus++;
 124                 }
 125         }
 126
 127 #ifdef CONFIG_HOTPLUG_CPU
 128         /*
 129          * The possible CPUs are all those present on the chip.  We
 130          * will assign CPU numbers for possible cores as well.  Cores
 131          * are always consecutively numberd from 0.
 132          */
 133         for (id = 0; id < num_cores && id < NR_CPUS; id++) {
 134                 if (!(core_mask & (1 << id))) {
 135                         set_cpu_possible(cpus, true);
 136                         __cpu_number_map[id] = cpus;
 137                         __cpu_logical_map[cpus] = id;
 138                         cpus++;
 139                 }
 140         }
 141 #endif
 142
 143         octeon_smp_hotplug_setup();
 144 }
 145
 146 /**
 147  * Firmware CPU startup hook
 148  *
 149  */
 150 static void octeon_boot_secondary(int cpu, struct task_struct *idle)
 151 {
 152         int count;
 153
 154         pr_info("SMP: Booting CPU%02d (CoreId %2d)...\n", cpu,
 155                 cpu_logical_map(cpu));
 156
 157         octeon_processor_sp = __KSTK_TOS(idle);
 158         octeon_processor_gp = (unsigned long)(task_thread_info(idle));
 159         octeon_processor_boot = cpu_logical_map(cpu);
 160         mb();
 161
 162         count = 10000;
 163         while (octeon_processor_sp && count) {
 164                 /* Waiting for processor to get the SP and GP */
 165                 udelay(1);
 166                 count--;
 167         }
 168         if (count == 0)
 169                 pr_err("Secondary boot timeout\n");
 170 }
 171
 172 /**
 173  * After we've done initial boot, this function is called to allow the
 174  * board code to clean up state, if needed
 175  */
 176 static void __cpuinit octeon_init_secondary(void)
 177 {
 178         unsigned int sr;
 179
 180         sr = set_c0_status(ST0_BEV);
 181         write_c0_ebase((u32)ebase);
 182         write_c0_status(sr);
 183
 184         octeon_check_cpu_bist();
 185         octeon_init_cvmcount();
 186
 187         octeon_irq_setup_secondary();
 188         raw_local_irq_enable();
 189 }
 190
 191 /**
 192  * Callout to firmware before smp_init
 193  *
 194  */
 195 void octeon_prepare_cpus(unsigned int max_cpus)
 196 {
 197 #ifdef CONFIG_HOTPLUG_CPU
 198         struct linux_app_boot_info *labi;
 199
 200         labi = (struct linux_app_boot_info *)PHYS_TO_XKSEG_CACHED(LABI_ADDR_IN_BOOTLOADER);
 201
 202         if (labi->labi_signature != LABI_SIGNATURE)
 203                 panic("The bootloader version on this board is incorrect.");
 204 #endif
 205         /*
 206          * Only the low order mailbox bits are used for IPIs, leave
 207          * the other bits alone.
 208          */
 209         cvmx_write_csr(CVMX_CIU_MBOX_CLRX(cvmx_get_core_num()), 0xffff);
 210         if (request_irq(OCTEON_IRQ_MBOX0, mailbox_interrupt,
 211                         IRQF_PERCPU | IRQF_NO_THREAD, "SMP-IPI",
 212                         mailbox_interrupt)) {
 213                 panic("Cannot request_irq(OCTEON_IRQ_MBOX0)");
 214         }
 215 }
 216
 217 /**
 218  * Last chance for the board code to finish SMP initialization before
 219  * the CPU is "online".
 220  */
 221 static void octeon_smp_finish(void)
 222 {
 223 #ifdef CONFIG_CAVIUM_GDB
 224         unsigned long tmp;
 225         /* Pulse MCD0 signal on Ctrl-C to stop all the cores. Also set the MCD0
 226            to be not masked by this core so we know the signal is received by
 227            someone */
 228         asm volatile ("dmfc0 %0, $22\n"
 229                       "ori   %0, %0, 0x9100\n" "dmtc0 %0, $22\n" : "=r" (tmp));
 230 #endif
 231
 232         octeon_user_io_init();
 233
 234         /* to generate the first CPU timer interrupt */
 235         write_c0_compare(read_c0_count() + mips_hpt_frequency / HZ);
 236 }
 237
 238 /**
 239  * Hook for after all CPUs are online
 240  */
 241 static void octeon_cpus_done(void)
 242 {
 243 #ifdef CONFIG_CAVIUM_GDB
 244         unsigned long tmp;
 245         /* Pulse MCD0 signal on Ctrl-C to stop all the cores. Also set the MCD0
 246            to be not masked by this core so we know the signal is received by
 247            someone */
 248         asm volatile ("dmfc0 %0, $22\n"
 249                       "ori   %0, %0, 0x9100\n" "dmtc0 %0, $22\n" : "=r" (tmp));
 250 #endif
 251 }
 252
 253 #ifdef CONFIG_HOTPLUG_CPU
 254
 255 /* State of each CPU. */
 256 DEFINE_PER_CPU(int, cpu_state);
 257
 258 extern void fixup_irqs(void);
 259
 260 static DEFINE_SPINLOCK(smp_reserve_lock);
 261
 262 static int octeon_cpu_disable(void)
 263 {
 264         unsigned int cpu = smp_processor_id();
 265
 266         if (cpu == 0)
 267                 return -EBUSY;
 268
 269         spin_lock(&smp_reserve_lock);
 270
 271         cpu_clear(cpu, cpu_online_map);
 272         cpu_clear(cpu, cpu_callin_map);
 273         local_irq_disable();
 274         fixup_irqs();
 275         local_irq_enable();
 276
 277         flush_cache_all();
 278         local_flush_tlb_all();
 279
 280         spin_unlock(&smp_reserve_lock);
 281
 282         return 0;
 283 }
 284
 285 static void octeon_cpu_die(unsigned int cpu)
 286 {
 287         int coreid = cpu_logical_map(cpu);
 288         uint32_t mask, new_mask;
 289         const struct cvmx_bootmem_named_block_desc *block_desc;
 290
 291         while (per_cpu(cpu_state, cpu) != CPU_DEAD)
 292                 cpu_relax();
 293
 294         /*
 295          * This is a bit complicated strategics of getting/settig available
 296          * cores mask, copied from bootloader
 297          */
 298
 299         mask = 1 << coreid;
 300         /* LINUX_APP_BOOT_BLOCK is initialized in bootoct binary */
 301         block_desc = cvmx_bootmem_find_named_block(LINUX_APP_BOOT_BLOCK_NAME);
 302
 303         if (!block_desc) {
 304                 struct linux_app_boot_info *labi;
 305
 306                 labi = (struct linux_app_boot_info *)PHYS_TO_XKSEG_CACHED(LABI_ADDR_IN_BOOTLOADER);
 307
 308                 labi->avail_coremask |= mask;
 309                 new_mask = labi->avail_coremask;
 310         } else {                       /* alternative, already initialized */
 311                 uint32_t *p = (uint32_t *)PHYS_TO_XKSEG_CACHED(block_desc->base_addr +
 312                                                                AVAIL_COREMASK_OFFSET_IN_LINUX_APP_BOOT_BLOCK);
 313                 *p |= mask;
 314                 new_mask = *p;
 315         }
 316
 317         pr_info("Reset core %d. Available Coremask = 0x%x \n", coreid, new_mask);
 318         mb();
 319         cvmx_write_csr(CVMX_CIU_PP_RST, 1 << coreid);
 320         cvmx_write_csr(CVMX_CIU_PP_RST, 0);
 321 }
 322
 323 void play_dead(void)
 324 {
 325         int cpu = cpu_number_map(cvmx_get_core_num());
 326
 327         idle_task_exit();
 328         octeon_processor_boot = 0xff;
 329         per_cpu(cpu_state, cpu) = CPU_DEAD;
 330
 331         mb();
 332
 333         while (1)       /* core will be reset here */
 334                 ;
 335 }
 336
 337 extern void kernel_entry(unsigned long arg1, ...);
 338
 339 static void start_after_reset(void)
 340 {
 341         kernel_entry(0, 0, 0);  /* set a2 = 0 for secondary core */
 342 }
 343
 344 static int octeon_update_boot_vector(unsigned int cpu)
 345 {
 346
 347         int coreid = cpu_logical_map(cpu);
 348         uint32_t avail_coremask;
 349         const struct cvmx_bootmem_named_block_desc *block_desc;
 350         struct boot_init_vector *boot_vect =
 351                 (struct boot_init_vector *)PHYS_TO_XKSEG_CACHED(BOOTLOADER_BOOT_VECTOR);
 352
 353         block_desc = cvmx_bootmem_find_named_block(LINUX_APP_BOOT_BLOCK_NAME);
 354
 355         if (!block_desc) {
 356                 struct linux_app_boot_info *labi;
 357
 358                 labi = (struct linux_app_boot_info *)PHYS_TO_XKSEG_CACHED(LABI_ADDR_IN_BOOTLOADER);
 359
 360                 avail_coremask = labi->avail_coremask;
 361                 labi->avail_coremask &= ~(1 << coreid);
 362         } else {                       /* alternative, already initialized */
 363                 avail_coremask = *(uint32_t *)PHYS_TO_XKSEG_CACHED(
 364                         block_desc->base_addr + AVAIL_COREMASK_OFFSET_IN_LINUX_APP_BOOT_BLOCK);
 365         }
 366
 367         if (!(avail_coremask & (1 << coreid))) {
 368                 /* core not available, assume, that catched by simple-executive */
 369                 cvmx_write_csr(CVMX_CIU_PP_RST, 1 << coreid);
 370                 cvmx_write_csr(CVMX_CIU_PP_RST, 0);
 371         }
 372
 373         boot_vect[coreid].app_start_func_addr =
 374                 (uint32_t) (unsigned long) start_after_reset;
 375         boot_vect[coreid].code_addr = octeon_bootloader_entry_addr;
 376
 377         mb();
 378
 379         cvmx_write_csr(CVMX_CIU_NMI, (1 << coreid) & avail_coremask);
 380
 381         return 0;
 382 }
 383
 384 static int __cpuinit octeon_cpu_callback(struct notifier_block *nfb,
 385         unsigned long action, void *hcpu)
 386 {
 387         unsigned int cpu = (unsigned long)hcpu;
 388
 389         switch (action) {
 390         case CPU_UP_PREPARE:
 391                 octeon_update_boot_vector(cpu);
 392                 break;
 393         case CPU_ONLINE:
 394                 pr_info("Cpu %d online\n", cpu);
 395                 break;
 396         case CPU_DEAD:
 397                 break;
 398         }
 399
 400         return NOTIFY_OK;
 401 }
 402
 403 static int __cpuinit register_cavium_notifier(void)
 404 {
 405         hotcpu_notifier(octeon_cpu_callback, 0);
 406         return 0;
 407 }
 408 late_initcall(register_cavium_notifier);
 409
 410 #endif  /* CONFIG_HOTPLUG_CPU */
 411
 412 struct plat_smp_ops octeon_smp_ops = {
 413         .send_ipi_single        = octeon_send_ipi_single,
 414         .send_ipi_mask          = octeon_send_ipi_mask,
 415         .init_secondary         = octeon_init_secondary,
 416         .smp_finish             = octeon_smp_finish,
 417         .cpus_done              = octeon_cpus_done,
 418         .boot_secondary         = octeon_boot_secondary,
 419         .smp_setup              = octeon_smp_setup,
 420         .prepare_cpus           = octeon_prepare_cpus,
 421 #ifdef CONFIG_HOTPLUG_CPU
 422         .cpu_disable            = octeon_cpu_disable,
 423         .cpu_die                = octeon_cpu_die,
 424 #endif
 425 };