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, IRQF_DISABLED,
 211                         "SMP-IPI", mailbox_interrupt)) {
 212                 panic("Cannot request_irq(OCTEON_IRQ_MBOX0)\n");
 213         }
 214 }
 215
 216 /**
 217  * Last chance for the board code to finish SMP initialization before
 218  * the CPU is "online".
 219  */
 220 static void octeon_smp_finish(void)
 221 {
 222 #ifdef CONFIG_CAVIUM_GDB
 223         unsigned long tmp;
 224         /* Pulse MCD0 signal on Ctrl-C to stop all the cores. Also set the MCD0
 225            to be not masked by this core so we know the signal is received by
 226            someone */
 227         asm volatile ("dmfc0 %0, $22\n"
 228                       "ori   %0, %0, 0x9100\n" "dmtc0 %0, $22\n" : "=r" (tmp));
 229 #endif
 230
 231         octeon_user_io_init();
 232
 233         /* to generate the first CPU timer interrupt */
 234         write_c0_compare(read_c0_count() + mips_hpt_frequency / HZ);
 235 }
 236
 237 /**
 238  * Hook for after all CPUs are online
 239  */
 240 static void octeon_cpus_done(void)
 241 {
 242 #ifdef CONFIG_CAVIUM_GDB
 243         unsigned long tmp;
 244         /* Pulse MCD0 signal on Ctrl-C to stop all the cores. Also set the MCD0
 245            to be not masked by this core so we know the signal is received by
 246            someone */
 247         asm volatile ("dmfc0 %0, $22\n"
 248                       "ori   %0, %0, 0x9100\n" "dmtc0 %0, $22\n" : "=r" (tmp));
 249 #endif
 250 }
 251
 252 #ifdef CONFIG_HOTPLUG_CPU
 253
 254 /* State of each CPU. */
 255 DEFINE_PER_CPU(int, cpu_state);
 256
 257 extern void fixup_irqs(void);
 258
 259 static DEFINE_SPINLOCK(smp_reserve_lock);
 260
 261 static int octeon_cpu_disable(void)
 262 {
 263         unsigned int cpu = smp_processor_id();
 264
 265         if (cpu == 0)
 266                 return -EBUSY;
 267
 268         spin_lock(&smp_reserve_lock);
 269
 270         cpu_clear(cpu, cpu_online_map);
 271         cpu_clear(cpu, cpu_callin_map);
 272         local_irq_disable();
 273         fixup_irqs();
 274         local_irq_enable();
 275
 276         flush_cache_all();
 277         local_flush_tlb_all();
 278
 279         spin_unlock(&smp_reserve_lock);
 280
 281         return 0;
 282 }
 283
 284 static void octeon_cpu_die(unsigned int cpu)
 285 {
 286         int coreid = cpu_logical_map(cpu);
 287         uint32_t mask, new_mask;
 288         const struct cvmx_bootmem_named_block_desc *block_desc;
 289
 290         while (per_cpu(cpu_state, cpu) != CPU_DEAD)
 291                 cpu_relax();
 292
 293         /*
 294          * This is a bit complicated strategics of getting/settig available
 295          * cores mask, copied from bootloader
 296          */
 297
 298         mask = 1 << coreid;
 299         /* LINUX_APP_BOOT_BLOCK is initialized in bootoct binary */
 300         block_desc = cvmx_bootmem_find_named_block(LINUX_APP_BOOT_BLOCK_NAME);
 301
 302         if (!block_desc) {
 303                 struct linux_app_boot_info *labi;
 304
 305                 labi = (struct linux_app_boot_info *)PHYS_TO_XKSEG_CACHED(LABI_ADDR_IN_BOOTLOADER);
 306
 307                 labi->avail_coremask |= mask;
 308                 new_mask = labi->avail_coremask;
 309         } else {                       /* alternative, already initialized */
 310                 uint32_t *p = (uint32_t *)PHYS_TO_XKSEG_CACHED(block_desc->base_addr +
 311                                                                AVAIL_COREMASK_OFFSET_IN_LINUX_APP_BOOT_BLOCK);
 312                 *p |= mask;
 313                 new_mask = *p;
 314         }
 315
 316         pr_info("Reset core %d. Available Coremask = 0x%x \n", coreid, new_mask);
 317         mb();
 318         cvmx_write_csr(CVMX_CIU_PP_RST, 1 << coreid);
 319         cvmx_write_csr(CVMX_CIU_PP_RST, 0);
 320 }
 321
 322 void play_dead(void)
 323 {
 324         int cpu = cpu_number_map(cvmx_get_core_num());
 325
 326         idle_task_exit();
 327         octeon_processor_boot = 0xff;
 328         per_cpu(cpu_state, cpu) = CPU_DEAD;
 329
 330         mb();
 331
 332         while (1)       /* core will be reset here */
 333                 ;
 334 }
 335
 336 extern void kernel_entry(unsigned long arg1, ...);
 337
 338 static void start_after_reset(void)
 339 {
 340         kernel_entry(0, 0, 0);  /* set a2 = 0 for secondary core */
 341 }
 342
 343 static int octeon_update_boot_vector(unsigned int cpu)
 344 {
 345
 346         int coreid = cpu_logical_map(cpu);
 347         uint32_t avail_coremask;
 348         const struct cvmx_bootmem_named_block_desc *block_desc;
 349         struct boot_init_vector *boot_vect =
 350                 (struct boot_init_vector *)PHYS_TO_XKSEG_CACHED(BOOTLOADER_BOOT_VECTOR);
 351
 352         block_desc = cvmx_bootmem_find_named_block(LINUX_APP_BOOT_BLOCK_NAME);
 353
 354         if (!block_desc) {
 355                 struct linux_app_boot_info *labi;
 356
 357                 labi = (struct linux_app_boot_info *)PHYS_TO_XKSEG_CACHED(LABI_ADDR_IN_BOOTLOADER);
 358
 359                 avail_coremask = labi->avail_coremask;
 360                 labi->avail_coremask &= ~(1 << coreid);
 361         } else {                       /* alternative, already initialized */
 362                 avail_coremask = *(uint32_t *)PHYS_TO_XKSEG_CACHED(
 363                         block_desc->base_addr + AVAIL_COREMASK_OFFSET_IN_LINUX_APP_BOOT_BLOCK);
 364         }
 365
 366         if (!(avail_coremask & (1 << coreid))) {
 367                 /* core not available, assume, that catched by simple-executive */
 368                 cvmx_write_csr(CVMX_CIU_PP_RST, 1 << coreid);
 369                 cvmx_write_csr(CVMX_CIU_PP_RST, 0);
 370         }
 371
 372         boot_vect[coreid].app_start_func_addr =
 373                 (uint32_t) (unsigned long) start_after_reset;
 374         boot_vect[coreid].code_addr = octeon_bootloader_entry_addr;
 375
 376         mb();
 377
 378         cvmx_write_csr(CVMX_CIU_NMI, (1 << coreid) & avail_coremask);
 379
 380         return 0;
 381 }
 382
 383 static int __cpuinit octeon_cpu_callback(struct notifier_block *nfb,
 384         unsigned long action, void *hcpu)
 385 {
 386         unsigned int cpu = (unsigned long)hcpu;
 387
 388         switch (action) {
 389         case CPU_UP_PREPARE:
 390                 octeon_update_boot_vector(cpu);
 391                 break;
 392         case CPU_ONLINE:
 393                 pr_info("Cpu %d online\n", cpu);
 394                 break;
 395         case CPU_DEAD:
 396                 break;
 397         }
 398
 399         return NOTIFY_OK;
 400 }
 401
 402 static int __cpuinit register_cavium_notifier(void)
 403 {
 404         hotcpu_notifier(octeon_cpu_callback, 0);
 405         return 0;
 406 }
 407 late_initcall(register_cavium_notifier);
 408
 409 #endif  /* CONFIG_HOTPLUG_CPU */
 410
 411 struct plat_smp_ops octeon_smp_ops = {
 412         .send_ipi_single        = octeon_send_ipi_single,
 413         .send_ipi_mask          = octeon_send_ipi_mask,
 414         .init_secondary         = octeon_init_secondary,
 415         .smp_finish             = octeon_smp_finish,
 416         .cpus_done              = octeon_cpus_done,
 417         .boot_secondary         = octeon_boot_secondary,
 418         .smp_setup              = octeon_smp_setup,
 419         .prepare_cpus           = octeon_prepare_cpus,
 420 #ifdef CONFIG_HOTPLUG_CPU
 421         .cpu_disable            = octeon_cpu_disable,
 422         .cpu_die                = octeon_cpu_die,
 423 #endif
 424 };