arch/mips/kernel/smp-bmips.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) 2011 by Kevin Cernekee (cernekee@gmail.com)
   7  *
   8  * SMP support for BMIPS
   9  */
  10
  11 #include <linux/init.h>
  12 #include <linux/sched.h>
  13 #include <linux/sched/hotplug.h>
  14 #include <linux/sched/task_stack.h>
  15 #include <linux/mm.h>
  16 #include <linux/delay.h>
  17 #include <linux/smp.h>
  18 #include <linux/interrupt.h>
  19 #include <linux/spinlock.h>
  20 #include <linux/cpu.h>
  21 #include <linux/cpumask.h>
  22 #include <linux/reboot.h>
  23 #include <linux/io.h>
  24 #include <linux/compiler.h>
  25 #include <linux/linkage.h>
  26 #include <linux/bug.h>
  27 #include <linux/kernel.h>
  28 #include <linux/kexec.h>
  29 #include <linux/irq.h>
  30
  31 #include <asm/time.h>
  32 #include <asm/processor.h>
  33 #include <asm/bootinfo.h>
  34 #include <asm/cacheflush.h>
  35 #include <asm/tlbflush.h>
  36 #include <asm/mipsregs.h>
  37 #include <asm/bmips.h>
  38 #include <asm/traps.h>
  39 #include <asm/barrier.h>
  40 #include <asm/cpu-features.h>
  41
  42 static int __maybe_unused max_cpus = 1;
  43
  44 /* these may be configured by the platform code */
  45 int bmips_smp_enabled = 1;
  46 int bmips_cpu_offset;
  47 cpumask_t bmips_booted_mask;
  48 unsigned long bmips_tp1_irqs = IE_IRQ1;
  49
  50 #define RESET_FROM_KSEG0                0x80080800
  51 #define RESET_FROM_KSEG1                0xa0080800
  52
  53 static void bmips_set_reset_vec(int cpu, u32 val);
  54
  55 #ifdef CONFIG_SMP
  56
  57 #include <asm/smp.h>
  58
  59 /* initial $sp, $gp - used by arch/mips/kernel/bmips_vec.S */
  60 unsigned long bmips_smp_boot_sp;
  61 unsigned long bmips_smp_boot_gp;
  62
  63 static void bmips43xx_send_ipi_single(int cpu, unsigned int action);
  64 static void bmips5000_send_ipi_single(int cpu, unsigned int action);
  65 static irqreturn_t bmips43xx_ipi_interrupt(int irq, void *dev_id);
  66 static irqreturn_t bmips5000_ipi_interrupt(int irq, void *dev_id);
  67
  68 /* SW interrupts 0,1 are used for interprocessor signaling */
  69 #define IPI0_IRQ                        (MIPS_CPU_IRQ_BASE + 0)
  70 #define IPI1_IRQ                        (MIPS_CPU_IRQ_BASE + 1)
  71
  72 #define CPUNUM(cpu, shift)              (((cpu) + bmips_cpu_offset) << (shift))
  73 #define ACTION_CLR_IPI(cpu, ipi)        (0x2000 | CPUNUM(cpu, 9) | ((ipi) << 8))
  74 #define ACTION_SET_IPI(cpu, ipi)        (0x3000 | CPUNUM(cpu, 9) | ((ipi) << 8))
  75 #define ACTION_BOOT_THREAD(cpu)         (0x08 | CPUNUM(cpu, 0))
  76
  77 static void __init bmips_smp_setup(void)
  78 {
  79         int i, cpu = 1, boot_cpu = 0;
  80         int cpu_hw_intr;
  81
  82         switch (current_cpu_type()) {
  83         case CPU_BMIPS4350:
  84         case CPU_BMIPS4380:
  85                 /* arbitration priority */
  86                 clear_c0_brcm_cmt_ctrl(0x30);
  87
  88                 /* NBK and weak order flags */
  89                 set_c0_brcm_config_0(0x30000);
  90
  91                 /* Find out if we are running on TP0 or TP1 */
  92                 boot_cpu = !!(read_c0_brcm_cmt_local() & (1 << 31));
  93
  94                 /*
  95                  * MIPS interrupts 0,1 (SW INT 0,1) cross over to the other
  96                  * thread
  97                  * MIPS interrupt 2 (HW INT 0) is the CPU0 L1 controller output
  98                  * MIPS interrupt 3 (HW INT 1) is the CPU1 L1 controller output
  99                  */
 100                 if (boot_cpu == 0)
 101                         cpu_hw_intr = 0x02;
 102                 else
 103                         cpu_hw_intr = 0x1d;
 104
 105                 change_c0_brcm_cmt_intr(0xf8018000,
 106                                         (cpu_hw_intr << 27) | (0x03 << 15));
 107
 108                 /* single core, 2 threads (2 pipelines) */
 109                 max_cpus = 2;
 110
 111                 break;
 112         case CPU_BMIPS5000:
 113                 /* enable raceless SW interrupts */
 114                 set_c0_brcm_config(0x03 << 22);
 115
 116                 /* route HW interrupt 0 to CPU0, HW interrupt 1 to CPU1 */
 117                 change_c0_brcm_mode(0x1f << 27, 0x02 << 27);
 118
 119                 /* N cores, 2 threads per core */
 120                 max_cpus = (((read_c0_brcm_config() >> 6) & 0x03) + 1) << 1;
 121
 122                 /* clear any pending SW interrupts */
 123                 for (i = 0; i < max_cpus; i++) {
 124                         write_c0_brcm_action(ACTION_CLR_IPI(i, 0));
 125                         write_c0_brcm_action(ACTION_CLR_IPI(i, 1));
 126                 }
 127
 128                 break;
 129         default:
 130                 max_cpus = 1;
 131         }
 132
 133         if (!bmips_smp_enabled)
 134                 max_cpus = 1;
 135
 136         /* this can be overridden by the BSP */
 137         if (!board_ebase_setup)
 138                 board_ebase_setup = &bmips_ebase_setup;
 139
 140         if (max_cpus > 1) {
 141                 __cpu_number_map[boot_cpu] = 0;
 142                 __cpu_logical_map[0] = boot_cpu;
 143
 144                 for (i = 0; i < max_cpus; i++) {
 145                         if (i != boot_cpu) {
 146                                 __cpu_number_map[i] = cpu;
 147                                 __cpu_logical_map[cpu] = i;
 148                                 cpu++;
 149                         }
 150                         set_cpu_possible(i, 1);
 151                         set_cpu_present(i, 1);
 152                 }
 153         } else {
 154                 __cpu_number_map[0] = boot_cpu;
 155                 __cpu_logical_map[0] = 0;
 156                 set_cpu_possible(0, 1);
 157                 set_cpu_present(0, 1);
 158         }
 159 }
 160
 161 /*
 162  * IPI IRQ setup - runs on CPU0
 163  */
 164 static void bmips_prepare_cpus(unsigned int max_cpus)
 165 {
 166         irqreturn_t (*bmips_ipi_interrupt)(int irq, void *dev_id);
 167
 168         switch (current_cpu_type()) {
 169         case CPU_BMIPS4350:
 170         case CPU_BMIPS4380:
 171                 bmips_ipi_interrupt = bmips43xx_ipi_interrupt;
 172                 break;
 173         case CPU_BMIPS5000:
 174                 bmips_ipi_interrupt = bmips5000_ipi_interrupt;
 175                 break;
 176         default:
 177                 return;
 178         }
 179
 180         if (request_irq(IPI0_IRQ, bmips_ipi_interrupt,
 181                         IRQF_PERCPU | IRQF_NO_SUSPEND, "smp_ipi0", NULL))
 182                 panic("Can't request IPI0 interrupt");
 183         if (request_irq(IPI1_IRQ, bmips_ipi_interrupt,
 184                         IRQF_PERCPU | IRQF_NO_SUSPEND, "smp_ipi1", NULL))
 185                 panic("Can't request IPI1 interrupt");
 186 }
 187
 188 /*
 189  * Tell the hardware to boot CPUx - runs on CPU0
 190  */
 191 static int bmips_boot_secondary(int cpu, struct task_struct *idle)
 192 {
 193         bmips_smp_boot_sp = __KSTK_TOS(idle);
 194         bmips_smp_boot_gp = (unsigned long)task_thread_info(idle);
 195         mb();
 196
 197         /*
 198          * Initial boot sequence for secondary CPU:
 199          *   bmips_reset_nmi_vec @ a000_0000 ->
 200          *   bmips_smp_entry ->
 201          *   plat_wired_tlb_setup (cached function call; optional) ->
 202          *   start_secondary (cached jump)
 203          *
 204          * Warm restart sequence:
 205          *   play_dead WAIT loop ->
 206          *   bmips_smp_int_vec @ BMIPS_WARM_RESTART_VEC ->
 207          *   eret to play_dead ->
 208          *   bmips_secondary_reentry ->
 209          *   start_secondary
 210          */
 211
 212         pr_info("SMP: Booting CPU%d...\n", cpu);
 213
 214         if (cpumask_test_cpu(cpu, &bmips_booted_mask)) {
 215                 /* kseg1 might not exist if this CPU enabled XKS01 */
 216                 bmips_set_reset_vec(cpu, RESET_FROM_KSEG0);
 217
 218                 switch (current_cpu_type()) {
 219                 case CPU_BMIPS4350:
 220                 case CPU_BMIPS4380:
 221                         bmips43xx_send_ipi_single(cpu, 0);
 222                         break;
 223                 case CPU_BMIPS5000:
 224                         bmips5000_send_ipi_single(cpu, 0);
 225                         break;
 226                 }
 227         } else {
 228                 bmips_set_reset_vec(cpu, RESET_FROM_KSEG1);
 229
 230                 switch (current_cpu_type()) {
 231                 case CPU_BMIPS4350:
 232                 case CPU_BMIPS4380:
 233                         /* Reset slave TP1 if booting from TP0 */
 234                         if (cpu_logical_map(cpu) == 1)
 235                                 set_c0_brcm_cmt_ctrl(0x01);
 236                         break;
 237                 case CPU_BMIPS5000:
 238                         write_c0_brcm_action(ACTION_BOOT_THREAD(cpu));
 239                         break;
 240                 }
 241                 cpumask_set_cpu(cpu, &bmips_booted_mask);
 242         }
 243
 244         return 0;
 245 }
 246
 247 /*
 248  * Early setup - runs on secondary CPU after cache probe
 249  */
 250 static void bmips_init_secondary(void)
 251 {
 252         bmips_cpu_setup();
 253
 254         switch (current_cpu_type()) {
 255         case CPU_BMIPS4350:
 256         case CPU_BMIPS4380:
 257                 clear_c0_cause(smp_processor_id() ? C_SW1 : C_SW0);
 258                 break;
 259         case CPU_BMIPS5000:
 260                 write_c0_brcm_action(ACTION_CLR_IPI(smp_processor_id(), 0));
 261                 cpu_set_core(&current_cpu_data, (read_c0_brcm_config() >> 25) & 3);
 262                 break;
 263         }
 264 }
 265
 266 /*
 267  * Late setup - runs on secondary CPU before entering the idle loop
 268  */
 269 static void bmips_smp_finish(void)
 270 {
 271         pr_info("SMP: CPU%d is running\n", smp_processor_id());
 272
 273         /* make sure there won't be a timer interrupt for a little while */
 274         write_c0_compare(read_c0_count() + mips_hpt_frequency / HZ);
 275
 276         irq_enable_hazard();
 277         set_c0_status(IE_SW0 | IE_SW1 | bmips_tp1_irqs | IE_IRQ5 | ST0_IE);
 278         irq_enable_hazard();
 279 }
 280
 281 /*
 282  * BMIPS5000 raceless IPIs
 283  *
 284  * Each CPU has two inbound SW IRQs which are independent of all other CPUs.
 285  * IPI0 is used for SMP_RESCHEDULE_YOURSELF
 286  * IPI1 is used for SMP_CALL_FUNCTION
 287  */
 288
 289 static void bmips5000_send_ipi_single(int cpu, unsigned int action)
 290 {
 291         write_c0_brcm_action(ACTION_SET_IPI(cpu, action == SMP_CALL_FUNCTION));
 292 }
 293
 294 static irqreturn_t bmips5000_ipi_interrupt(int irq, void *dev_id)
 295 {
 296         int action = irq - IPI0_IRQ;
 297
 298         write_c0_brcm_action(ACTION_CLR_IPI(smp_processor_id(), action));
 299
 300         if (action == 0)
 301                 scheduler_ipi();
 302         else
 303                 generic_smp_call_function_interrupt();
 304
 305         return IRQ_HANDLED;
 306 }
 307
 308 static void bmips5000_send_ipi_mask(const struct cpumask *mask,
 309         unsigned int action)
 310 {
 311         unsigned int i;
 312
 313         for_each_cpu(i, mask)
 314                 bmips5000_send_ipi_single(i, action);
 315 }
 316
 317 /*
 318  * BMIPS43xx racey IPIs
 319  *
 320  * We use one inbound SW IRQ for each CPU.
 321  *
 322  * A spinlock must be held in order to keep CPUx from accidentally clearing
 323  * an incoming IPI when it writes CP0 CAUSE to raise an IPI on CPUy.  The
 324  * same spinlock is used to protect the action masks.
 325  */
 326
 327 static DEFINE_SPINLOCK(ipi_lock);
 328 static DEFINE_PER_CPU(int, ipi_action_mask);
 329
 330 static void bmips43xx_send_ipi_single(int cpu, unsigned int action)
 331 {
 332         unsigned long flags;
 333
 334         spin_lock_irqsave(&ipi_lock, flags);
 335         set_c0_cause(cpu ? C_SW1 : C_SW0);
 336         per_cpu(ipi_action_mask, cpu) |= action;
 337         irq_enable_hazard();
 338         spin_unlock_irqrestore(&ipi_lock, flags);
 339 }
 340
 341 static irqreturn_t bmips43xx_ipi_interrupt(int irq, void *dev_id)
 342 {
 343         unsigned long flags;
 344         int action, cpu = irq - IPI0_IRQ;
 345
 346         spin_lock_irqsave(&ipi_lock, flags);
 347         action = __this_cpu_read(ipi_action_mask);
 348         per_cpu(ipi_action_mask, cpu) = 0;
 349         clear_c0_cause(cpu ? C_SW1 : C_SW0);
 350         spin_unlock_irqrestore(&ipi_lock, flags);
 351
 352         if (action & SMP_RESCHEDULE_YOURSELF)
 353                 scheduler_ipi();
 354         if (action & SMP_CALL_FUNCTION)
 355                 generic_smp_call_function_interrupt();
 356
 357         return IRQ_HANDLED;
 358 }
 359
 360 static void bmips43xx_send_ipi_mask(const struct cpumask *mask,
 361         unsigned int action)
 362 {
 363         unsigned int i;
 364
 365         for_each_cpu(i, mask)
 366                 bmips43xx_send_ipi_single(i, action);
 367 }
 368
 369 #ifdef CONFIG_HOTPLUG_CPU
 370
 371 static int bmips_cpu_disable(void)
 372 {
 373         unsigned int cpu = smp_processor_id();
 374
 375         pr_info("SMP: CPU%d is offline\n", cpu);
 376
 377         set_cpu_online(cpu, false);
 378         calculate_cpu_foreign_map();
 379         irq_migrate_all_off_this_cpu();
 380         clear_c0_status(IE_IRQ5);
 381
 382         local_flush_tlb_all();
 383         local_flush_icache_range(0, ~0);
 384
 385         return 0;
 386 }
 387
 388 static void bmips_cpu_die(unsigned int cpu)
 389 {
 390 }
 391
 392 void __ref play_dead(void)
 393 {
 394         idle_task_exit();
 395         cpuhp_ap_report_dead();
 396
 397         /* flush data cache */
 398         _dma_cache_wback_inv(0, ~0);
 399
 400         /*
 401          * Wakeup is on SW0 or SW1; disable everything else
 402          * Use BEV !IV (BMIPS_WARM_RESTART_VEC) to avoid the regular Linux
 403          * IRQ handlers; this clears ST0_IE and returns immediately.
 404          */
 405         clear_c0_cause(CAUSEF_IV | C_SW0 | C_SW1);
 406         change_c0_status(
 407                 IE_IRQ5 | bmips_tp1_irqs | IE_SW0 | IE_SW1 | ST0_IE | ST0_BEV,
 408                 IE_SW0 | IE_SW1 | ST0_IE | ST0_BEV);
 409         irq_disable_hazard();
 410
 411         /*
 412          * wait for SW interrupt from bmips_boot_secondary(), then jump
 413          * back to start_secondary()
 414          */
 415         __asm__ __volatile__(
 416         "       wait\n"
 417         "       j       bmips_secondary_reentry\n"
 418         : : : "memory");
 419
 420         BUG();
 421 }
 422
 423 #endif /* CONFIG_HOTPLUG_CPU */
 424
 425 const struct plat_smp_ops bmips43xx_smp_ops = {
 426         .smp_setup              = bmips_smp_setup,
 427         .prepare_cpus           = bmips_prepare_cpus,
 428         .boot_secondary         = bmips_boot_secondary,
 429         .smp_finish             = bmips_smp_finish,
 430         .init_secondary         = bmips_init_secondary,
 431         .send_ipi_single        = bmips43xx_send_ipi_single,
 432         .send_ipi_mask          = bmips43xx_send_ipi_mask,
 433 #ifdef CONFIG_HOTPLUG_CPU
 434         .cpu_disable            = bmips_cpu_disable,
 435         .cpu_die                = bmips_cpu_die,
 436 #endif
 437 #ifdef CONFIG_KEXEC_CORE
 438         .kexec_nonboot_cpu      = kexec_nonboot_cpu_jump,
 439 #endif
 440 };
 441
 442 const struct plat_smp_ops bmips5000_smp_ops = {
 443         .smp_setup              = bmips_smp_setup,
 444         .prepare_cpus           = bmips_prepare_cpus,
 445         .boot_secondary         = bmips_boot_secondary,
 446         .smp_finish             = bmips_smp_finish,
 447         .init_secondary         = bmips_init_secondary,
 448         .send_ipi_single        = bmips5000_send_ipi_single,
 449         .send_ipi_mask          = bmips5000_send_ipi_mask,
 450 #ifdef CONFIG_HOTPLUG_CPU
 451         .cpu_disable            = bmips_cpu_disable,
 452         .cpu_die                = bmips_cpu_die,
 453 #endif
 454 #ifdef CONFIG_KEXEC_CORE
 455         .kexec_nonboot_cpu      = kexec_nonboot_cpu_jump,
 456 #endif
 457 };
 458
 459 #endif /* CONFIG_SMP */
 460
 461 /***********************************************************************
 462  * BMIPS vector relocation
 463  * This is primarily used for SMP boot, but it is applicable to some
 464  * UP BMIPS systems as well.
 465  ***********************************************************************/
 466
 467 static void bmips_wr_vec(unsigned long dst, char *start, char *end)
 468 {
 469         memcpy((void *)dst, start, end - start);
 470         dma_cache_wback(dst, end - start);
 471         local_flush_icache_range(dst, dst + (end - start));
 472         instruction_hazard();
 473 }
 474
 475 static inline void bmips_nmi_handler_setup(void)
 476 {
 477         bmips_wr_vec(BMIPS_NMI_RESET_VEC, bmips_reset_nmi_vec,
 478                 bmips_reset_nmi_vec_end);
 479         bmips_wr_vec(BMIPS_WARM_RESTART_VEC, bmips_smp_int_vec,
 480                 bmips_smp_int_vec_end);
 481 }
 482
 483 struct reset_vec_info {
 484         int cpu;
 485         u32 val;
 486 };
 487
 488 static void bmips_set_reset_vec_remote(void *vinfo)
 489 {
 490         struct reset_vec_info *info = vinfo;
 491         int shift = info->cpu & 0x01 ? 16 : 0;
 492         u32 mask = ~(0xffff << shift), val = info->val >> 16;
 493
 494         preempt_disable();
 495         if (smp_processor_id() > 0) {
 496                 smp_call_function_single(0, &bmips_set_reset_vec_remote,
 497                                          info, 1);
 498         } else {
 499                 if (info->cpu & 0x02) {
 500                         /* BMIPS5200 "should" use mask/shift, but it's buggy */
 501                         bmips_write_zscm_reg(0xa0, (val << 16) | val);
 502                         bmips_read_zscm_reg(0xa0);
 503                 } else {
 504                         write_c0_brcm_bootvec((read_c0_brcm_bootvec() & mask) |
 505                                               (val << shift));
 506                 }
 507         }
 508         preempt_enable();
 509 }
 510
 511 static void bmips_set_reset_vec(int cpu, u32 val)
 512 {
 513         struct reset_vec_info info;
 514
 515         if (current_cpu_type() == CPU_BMIPS5000) {
 516                 /* this needs to run from CPU0 (which is always online) */
 517                 info.cpu = cpu;
 518                 info.val = val;
 519                 bmips_set_reset_vec_remote(&info);
 520         } else {
 521                 void __iomem *cbr = BMIPS_GET_CBR();
 522
 523                 if (cpu == 0)
 524                         __raw_writel(val, cbr + BMIPS_RELO_VECTOR_CONTROL_0);
 525                 else {
 526                         if (current_cpu_type() != CPU_BMIPS4380)
 527                                 return;
 528                         __raw_writel(val, cbr + BMIPS_RELO_VECTOR_CONTROL_1);
 529                 }
 530         }
 531         __sync();
 532         back_to_back_c0_hazard();
 533 }
 534
 535 void bmips_ebase_setup(void)
 536 {
 537         unsigned long new_ebase = ebase;
 538
 539         BUG_ON(ebase != CKSEG0);
 540
 541         switch (current_cpu_type()) {
 542         case CPU_BMIPS4350:
 543                 /*
 544                  * BMIPS4350 cannot relocate the normal vectors, but it
 545                  * can relocate the BEV=1 vectors.  So CPU1 starts up at
 546                  * the relocated BEV=1, IV=0 general exception vector @
 547                  * 0xa000_0380.
 548                  *
 549                  * set_uncached_handler() is used here because:
 550                  *  - CPU1 will run this from uncached space
 551                  *  - None of the cacheflush functions are set up yet
 552                  */
 553                 set_uncached_handler(BMIPS_WARM_RESTART_VEC - CKSEG0,
 554                         &bmips_smp_int_vec, 0x80);
 555                 __sync();
 556                 return;
 557         case CPU_BMIPS3300:
 558         case CPU_BMIPS4380:
 559                 /*
 560                  * 0x8000_0000: reset/NMI (initially in kseg1)
 561                  * 0x8000_0400: normal vectors
 562                  */
 563                 new_ebase = 0x80000400;
 564                 bmips_set_reset_vec(0, RESET_FROM_KSEG0);
 565                 break;
 566         case CPU_BMIPS5000:
 567                 /*
 568                  * 0x8000_0000: reset/NMI (initially in kseg1)
 569                  * 0x8000_1000: normal vectors
 570                  */
 571                 new_ebase = 0x80001000;
 572                 bmips_set_reset_vec(0, RESET_FROM_KSEG0);
 573                 write_c0_ebase(new_ebase);
 574                 break;
 575         default:
 576                 return;
 577         }
 578
 579         board_nmi_handler_setup = &bmips_nmi_handler_setup;
 580         ebase = new_ebase;
 581 }
 582
 583 asmlinkage void __weak plat_wired_tlb_setup(void)
 584 {
 585         /*
 586          * Called when starting/restarting a secondary CPU.
 587          * Kernel stacks and other important data might only be accessible
 588          * once the wired entries are present.
 589          */
 590 }
 591
 592 void bmips_cpu_setup(void)
 593 {
 594         void __iomem __maybe_unused *cbr = BMIPS_GET_CBR();
 595         u32 __maybe_unused cfg;
 596
 597         switch (current_cpu_type()) {
 598         case CPU_BMIPS3300:
 599                 /* Set BIU to async mode */
 600                 set_c0_brcm_bus_pll(BIT(22));
 601                 __sync();
 602
 603                 /* put the BIU back in sync mode */
 604                 clear_c0_brcm_bus_pll(BIT(22));
 605
 606                 /* clear BHTD to enable branch history table */
 607                 clear_c0_brcm_reset(BIT(16));
 608
 609                 /* Flush and enable RAC */
 610                 cfg = __raw_readl(cbr + BMIPS_RAC_CONFIG);
 611                 __raw_writel(cfg | 0x100, cbr + BMIPS_RAC_CONFIG);
 612                 __raw_readl(cbr + BMIPS_RAC_CONFIG);
 613
 614                 cfg = __raw_readl(cbr + BMIPS_RAC_CONFIG);
 615                 __raw_writel(cfg | 0xf, cbr + BMIPS_RAC_CONFIG);
 616                 __raw_readl(cbr + BMIPS_RAC_CONFIG);
 617
 618                 cfg = __raw_readl(cbr + BMIPS_RAC_ADDRESS_RANGE);
 619                 __raw_writel(cfg | 0x0fff0000, cbr + BMIPS_RAC_ADDRESS_RANGE);
 620                 __raw_readl(cbr + BMIPS_RAC_ADDRESS_RANGE);
 621                 break;
 622
 623         case CPU_BMIPS4380:
 624                 /* CBG workaround for early BMIPS4380 CPUs */
 625                 switch (read_c0_prid()) {
 626                 case 0x2a040:
 627                 case 0x2a042:
 628                 case 0x2a044:
 629                 case 0x2a060:
 630                         cfg = __raw_readl(cbr + BMIPS_L2_CONFIG);
 631                         __raw_writel(cfg & ~0x07000000, cbr + BMIPS_L2_CONFIG);
 632                         __raw_readl(cbr + BMIPS_L2_CONFIG);
 633                 }
 634
 635                 /* clear BHTD to enable branch history table */
 636                 clear_c0_brcm_config_0(BIT(21));
 637
 638                 /* XI/ROTR enable */
 639                 set_c0_brcm_config_0(BIT(23));
 640                 set_c0_brcm_cmt_ctrl(BIT(15));
 641                 break;
 642
 643         case CPU_BMIPS5000:
 644                 /* enable RDHWR, BRDHWR */
 645                 set_c0_brcm_config(BIT(17) | BIT(21));
 646
 647                 /* Disable JTB */
 648                 __asm__ __volatile__(
 649                 "       .set    noreorder\n"
 650                 "       li      $8, 0x5a455048\n"
 651                 "       .word   0x4088b00f\n"   /* mtc0 t0, $22, 15 */
 652                 "       .word   0x4008b008\n"   /* mfc0 t0, $22, 8 */
 653                 "       li      $9, 0x00008000\n"
 654                 "       or      $8, $8, $9\n"
 655                 "       .word   0x4088b008\n"   /* mtc0 t0, $22, 8 */
 656                 "       sync\n"
 657                 "       li      $8, 0x0\n"
 658                 "       .word   0x4088b00f\n"   /* mtc0 t0, $22, 15 */
 659                 "       .set    reorder\n"
 660                 : : : "$8", "$9");
 661
 662                 /* XI enable */
 663                 set_c0_brcm_config(BIT(27));
 664
 665                 /* enable MIPS32R2 ROR instruction for XI TLB handlers */
 666                 __asm__ __volatile__(
 667                 "       li      $8, 0x5a455048\n"
 668                 "       .word   0x4088b00f\n"   /* mtc0 $8, $22, 15 */
 669                 "       nop; nop; nop\n"
 670                 "       .word   0x4008b008\n"   /* mfc0 $8, $22, 8 */
 671                 "       lui     $9, 0x0100\n"
 672                 "       or      $8, $9\n"
 673                 "       .word   0x4088b008\n"   /* mtc0 $8, $22, 8 */
 674                 : : : "$8", "$9");
 675                 break;
 676         }
 677 }