arch/mips/sibyte/bcm1480/irq.c

   1 /*
   2  * Copyright (C) 2000,2001,2002,2003,2004 Broadcom Corporation
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public License
   6  * as published by the Free Software Foundation; either version 2
   7  * of the License, or (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  17  */
  18 #include <linux/kernel.h>
  19 #include <linux/init.h>
  20 #include <linux/linkage.h>
  21 #include <linux/interrupt.h>
  22 #include <linux/spinlock.h>
  23 #include <linux/mm.h>
  24 #include <linux/slab.h>
  25 #include <linux/kernel_stat.h>
  26
  27 #include <asm/errno.h>
  28 #include <asm/irq_regs.h>
  29 #include <asm/signal.h>
  30 #include <asm/system.h>
  31 #include <asm/io.h>
  32
  33 #include <asm/sibyte/bcm1480_regs.h>
  34 #include <asm/sibyte/bcm1480_int.h>
  35 #include <asm/sibyte/bcm1480_scd.h>
  36
  37 #include <asm/sibyte/sb1250_uart.h>
  38 #include <asm/sibyte/sb1250.h>
  39
  40 /*
  41  * These are the routines that handle all the low level interrupt stuff.
  42  * Actions handled here are: initialization of the interrupt map, requesting of
  43  * interrupt lines by handlers, dispatching if interrupts to handlers, probing
  44  * for interrupt lines
  45  */
  46
  47
  48 static void end_bcm1480_irq(unsigned int irq);
  49 static void enable_bcm1480_irq(unsigned int irq);
  50 static void disable_bcm1480_irq(unsigned int irq);
  51 static void ack_bcm1480_irq(unsigned int irq);
  52 #ifdef CONFIG_SMP
  53 static void bcm1480_set_affinity(unsigned int irq, cpumask_t mask);
  54 #endif
  55
  56 #ifdef CONFIG_PCI
  57 extern unsigned long ht_eoi_space;
  58 #endif
  59
  60 #ifdef CONFIG_KGDB
  61 #include <asm/gdb-stub.h>
  62 extern void breakpoint(void);
  63 static int kgdb_irq;
  64 #ifdef CONFIG_GDB_CONSOLE
  65 extern void register_gdb_console(void);
  66 #endif
  67
  68 /* kgdb is on when configured.  Pass "nokgdb" kernel arg to turn it off */
  69 static int kgdb_flag = 1;
  70 static int __init nokgdb(char *str)
  71 {
  72         kgdb_flag = 0;
  73         return 1;
  74 }
  75 __setup("nokgdb", nokgdb);
  76
  77 /* Default to UART1 */
  78 int kgdb_port = 1;
  79 #ifdef CONFIG_SIBYTE_SB1250_DUART
  80 extern char sb1250_duart_present[];
  81 #endif
  82 #endif
  83
  84 static struct irq_chip bcm1480_irq_type = {
  85         .name = "BCM1480-IMR",
  86         .ack = ack_bcm1480_irq,
  87         .mask = disable_bcm1480_irq,
  88         .mask_ack = ack_bcm1480_irq,
  89         .unmask = enable_bcm1480_irq,
  90         .end = end_bcm1480_irq,
  91 #ifdef CONFIG_SMP
  92         .set_affinity = bcm1480_set_affinity
  93 #endif
  94 };
  95
  96 /* Store the CPU id (not the logical number) */
  97 int bcm1480_irq_owner[BCM1480_NR_IRQS];
  98
  99 DEFINE_SPINLOCK(bcm1480_imr_lock);
 100
 101 void bcm1480_mask_irq(int cpu, int irq)
 102 {
 103         unsigned long flags;
 104         u64 cur_ints,hl_spacing;
 105
 106         spin_lock_irqsave(&bcm1480_imr_lock, flags);
 107         hl_spacing = 0;
 108         if ((irq >= BCM1480_NR_IRQS_HALF) && (irq <= BCM1480_NR_IRQS)) {
 109                 hl_spacing = BCM1480_IMR_HL_SPACING;
 110                 irq -= BCM1480_NR_IRQS_HALF;
 111         }
 112         cur_ints = ____raw_readq(IOADDR(A_BCM1480_IMR_MAPPER(cpu) + R_BCM1480_IMR_INTERRUPT_MASK_H + hl_spacing));
 113         cur_ints |= (((u64) 1) << irq);
 114         ____raw_writeq(cur_ints, IOADDR(A_BCM1480_IMR_MAPPER(cpu) + R_BCM1480_IMR_INTERRUPT_MASK_H + hl_spacing));
 115         spin_unlock_irqrestore(&bcm1480_imr_lock, flags);
 116 }
 117
 118 void bcm1480_unmask_irq(int cpu, int irq)
 119 {
 120         unsigned long flags;
 121         u64 cur_ints,hl_spacing;
 122
 123         spin_lock_irqsave(&bcm1480_imr_lock, flags);
 124         hl_spacing = 0;
 125         if ((irq >= BCM1480_NR_IRQS_HALF) && (irq <= BCM1480_NR_IRQS)) {
 126                 hl_spacing = BCM1480_IMR_HL_SPACING;
 127                 irq -= BCM1480_NR_IRQS_HALF;
 128         }
 129         cur_ints = ____raw_readq(IOADDR(A_BCM1480_IMR_MAPPER(cpu) + R_BCM1480_IMR_INTERRUPT_MASK_H + hl_spacing));
 130         cur_ints &= ~(((u64) 1) << irq);
 131         ____raw_writeq(cur_ints, IOADDR(A_BCM1480_IMR_MAPPER(cpu) + R_BCM1480_IMR_INTERRUPT_MASK_H + hl_spacing));
 132         spin_unlock_irqrestore(&bcm1480_imr_lock, flags);
 133 }
 134
 135 #ifdef CONFIG_SMP
 136 static void bcm1480_set_affinity(unsigned int irq, cpumask_t mask)
 137 {
 138         int i = 0, old_cpu, cpu, int_on, k;
 139         u64 cur_ints;
 140         struct irq_desc *desc = irq_desc + irq;
 141         unsigned long flags;
 142         unsigned int irq_dirty;
 143
 144         if (cpus_weight(mask) != 1) {
 145                 printk("attempted to set irq affinity for irq %d to multiple CPUs\n", irq);
 146                 return;
 147         }
 148         i = first_cpu(mask);
 149
 150         /* Convert logical CPU to physical CPU */
 151         cpu = cpu_logical_map(i);
 152
 153         /* Protect against other affinity changers and IMR manipulation */
 154         spin_lock_irqsave(&desc->lock, flags);
 155         spin_lock(&bcm1480_imr_lock);
 156
 157         /* Swizzle each CPU's IMR (but leave the IP selection alone) */
 158         old_cpu = bcm1480_irq_owner[irq];
 159         irq_dirty = irq;
 160         if ((irq_dirty >= BCM1480_NR_IRQS_HALF) && (irq_dirty <= BCM1480_NR_IRQS)) {
 161                 irq_dirty -= BCM1480_NR_IRQS_HALF;
 162         }
 163
 164         for (k=0; k<2; k++) { /* Loop through high and low interrupt mask register */
 165                 cur_ints = ____raw_readq(IOADDR(A_BCM1480_IMR_MAPPER(old_cpu) + R_BCM1480_IMR_INTERRUPT_MASK_H + (k*BCM1480_IMR_HL_SPACING)));
 166                 int_on = !(cur_ints & (((u64) 1) << irq_dirty));
 167                 if (int_on) {
 168                         /* If it was on, mask it */
 169                         cur_ints |= (((u64) 1) << irq_dirty);
 170                         ____raw_writeq(cur_ints, IOADDR(A_BCM1480_IMR_MAPPER(old_cpu) + R_BCM1480_IMR_INTERRUPT_MASK_H + (k*BCM1480_IMR_HL_SPACING)));
 171                 }
 172                 bcm1480_irq_owner[irq] = cpu;
 173                 if (int_on) {
 174                         /* unmask for the new CPU */
 175                         cur_ints = ____raw_readq(IOADDR(A_BCM1480_IMR_MAPPER(cpu) + R_BCM1480_IMR_INTERRUPT_MASK_H + (k*BCM1480_IMR_HL_SPACING)));
 176                         cur_ints &= ~(((u64) 1) << irq_dirty);
 177                         ____raw_writeq(cur_ints, IOADDR(A_BCM1480_IMR_MAPPER(cpu) + R_BCM1480_IMR_INTERRUPT_MASK_H + (k*BCM1480_IMR_HL_SPACING)));
 178                 }
 179         }
 180         spin_unlock(&bcm1480_imr_lock);
 181         spin_unlock_irqrestore(&desc->lock, flags);
 182 }
 183 #endif
 184
 185
 186 /*****************************************************************************/
 187
 188 static void disable_bcm1480_irq(unsigned int irq)
 189 {
 190         bcm1480_mask_irq(bcm1480_irq_owner[irq], irq);
 191 }
 192
 193 static void enable_bcm1480_irq(unsigned int irq)
 194 {
 195         bcm1480_unmask_irq(bcm1480_irq_owner[irq], irq);
 196 }
 197
 198
 199 static void ack_bcm1480_irq(unsigned int irq)
 200 {
 201         u64 pending;
 202         unsigned int irq_dirty;
 203         int k;
 204
 205         /*
 206          * If the interrupt was an HT interrupt, now is the time to
 207          * clear it.  NOTE: we assume the HT bridge was set up to
 208          * deliver the interrupts to all CPUs (which makes affinity
 209          * changing easier for us)
 210          */
 211         irq_dirty = irq;
 212         if ((irq_dirty >= BCM1480_NR_IRQS_HALF) && (irq_dirty <= BCM1480_NR_IRQS)) {
 213                 irq_dirty -= BCM1480_NR_IRQS_HALF;
 214         }
 215         for (k=0; k<2; k++) { /* Loop through high and low LDT interrupts */
 216                 pending = __raw_readq(IOADDR(A_BCM1480_IMR_REGISTER(bcm1480_irq_owner[irq],
 217                                                 R_BCM1480_IMR_LDT_INTERRUPT_H + (k*BCM1480_IMR_HL_SPACING))));
 218                 pending &= ((u64)1 << (irq_dirty));
 219                 if (pending) {
 220 #ifdef CONFIG_SMP
 221                         int i;
 222                         for (i=0; i<NR_CPUS; i++) {
 223                                 /*
 224                                  * Clear for all CPUs so an affinity switch
 225                                  * doesn't find an old status
 226                                  */
 227                                 __raw_writeq(pending, IOADDR(A_BCM1480_IMR_REGISTER(cpu_logical_map(i),
 228                                                                 R_BCM1480_IMR_LDT_INTERRUPT_CLR_H + (k*BCM1480_IMR_HL_SPACING))));
 229                         }
 230 #else
 231                         __raw_writeq(pending, IOADDR(A_BCM1480_IMR_REGISTER(0, R_BCM1480_IMR_LDT_INTERRUPT_CLR_H + (k*BCM1480_IMR_HL_SPACING))));
 232 #endif
 233
 234                         /*
 235                          * Generate EOI.  For Pass 1 parts, EOI is a nop.  For
 236                          * Pass 2, the LDT world may be edge-triggered, but
 237                          * this EOI shouldn't hurt.  If they are
 238                          * level-sensitive, the EOI is required.
 239                          */
 240 #ifdef CONFIG_PCI
 241                         if (ht_eoi_space)
 242                                 *(uint32_t *)(ht_eoi_space+(irq<<16)+(7<<2)) = 0;
 243 #endif
 244                 }
 245         }
 246         bcm1480_mask_irq(bcm1480_irq_owner[irq], irq);
 247 }
 248
 249
 250 static void end_bcm1480_irq(unsigned int irq)
 251 {
 252         if (!(irq_desc[irq].status & (IRQ_DISABLED | IRQ_INPROGRESS))) {
 253                 bcm1480_unmask_irq(bcm1480_irq_owner[irq], irq);
 254         }
 255 }
 256
 257
 258 void __init init_bcm1480_irqs(void)
 259 {
 260         int i;
 261
 262         for (i = 0; i < BCM1480_NR_IRQS; i++) {
 263                 set_irq_chip(i, &bcm1480_irq_type);
 264                 bcm1480_irq_owner[i] = 0;
 265         }
 266 }
 267
 268
 269 static irqreturn_t bcm1480_dummy_handler(int irq, void *dev_id)
 270 {
 271         return IRQ_NONE;
 272 }
 273
 274 static struct irqaction bcm1480_dummy_action = {
 275         .handler = bcm1480_dummy_handler,
 276         .flags   = 0,
 277         .mask    = CPU_MASK_NONE,
 278         .name    = "bcm1480-private",
 279         .next    = NULL,
 280         .dev_id  = 0
 281 };
 282
 283 int bcm1480_steal_irq(int irq)
 284 {
 285         struct irq_desc *desc = irq_desc + irq;
 286         unsigned long flags;
 287         int retval = 0;
 288
 289         if (irq >= BCM1480_NR_IRQS)
 290                 return -EINVAL;
 291
 292         spin_lock_irqsave(&desc->lock,flags);
 293         /* Don't allow sharing at all for these */
 294         if (desc->action != NULL)
 295                 retval = -EBUSY;
 296         else {
 297                 desc->action = &bcm1480_dummy_action;
 298                 desc->depth = 0;
 299         }
 300         spin_unlock_irqrestore(&desc->lock,flags);
 301         return 0;
 302 }
 303
 304 /*
 305  *  init_IRQ is called early in the boot sequence from init/main.c.  It
 306  *  is responsible for setting up the interrupt mapper and installing the
 307  *  handler that will be responsible for dispatching interrupts to the
 308  *  "right" place.
 309  */
 310 /*
 311  * For now, map all interrupts to IP[2].  We could save
 312  * some cycles by parceling out system interrupts to different
 313  * IP lines, but keep it simple for bringup.  We'll also direct
 314  * all interrupts to a single CPU; we should probably route
 315  * PCI and LDT to one cpu and everything else to the other
 316  * to balance the load a bit.
 317  *
 318  * On the second cpu, everything is set to IP5, which is
 319  * ignored, EXCEPT the mailbox interrupt.  That one is
 320  * set to IP[2] so it is handled.  This is needed so we
 321  * can do cross-cpu function calls, as requred by SMP
 322  */
 323
 324 #define IMR_IP2_VAL     K_BCM1480_INT_MAP_I0
 325 #define IMR_IP3_VAL     K_BCM1480_INT_MAP_I1
 326 #define IMR_IP4_VAL     K_BCM1480_INT_MAP_I2
 327 #define IMR_IP5_VAL     K_BCM1480_INT_MAP_I3
 328 #define IMR_IP6_VAL     K_BCM1480_INT_MAP_I4
 329
 330 void __init arch_init_irq(void)
 331 {
 332
 333         unsigned int i, cpu;
 334         u64 tmp;
 335         unsigned int imask = STATUSF_IP4 | STATUSF_IP3 | STATUSF_IP2 |
 336                 STATUSF_IP1 | STATUSF_IP0;
 337
 338         /* Default everything to IP2 */
 339         /* Start with _high registers which has no bit 0 interrupt source */
 340         for (i = 1; i < BCM1480_NR_IRQS_HALF; i++) {    /* was I0 */
 341                 for (cpu = 0; cpu < 4; cpu++) {
 342                         __raw_writeq(IMR_IP2_VAL,
 343                                      IOADDR(A_BCM1480_IMR_REGISTER(cpu,
 344                                                                    R_BCM1480_IMR_INTERRUPT_MAP_BASE_H) + (i << 3)));
 345                 }
 346         }
 347
 348         /* Now do _low registers */
 349         for (i = 0; i < BCM1480_NR_IRQS_HALF; i++) {
 350                 for (cpu = 0; cpu < 4; cpu++) {
 351                         __raw_writeq(IMR_IP2_VAL,
 352                                      IOADDR(A_BCM1480_IMR_REGISTER(cpu,
 353                                                                    R_BCM1480_IMR_INTERRUPT_MAP_BASE_L) + (i << 3)));
 354                 }
 355         }
 356
 357         init_bcm1480_irqs();
 358
 359         /*
 360          * Map the high 16 bits of mailbox_0 registers to IP[3], for
 361          * inter-cpu messages
 362          */
 363         /* Was I1 */
 364         for (cpu = 0; cpu < 4; cpu++) {
 365                 __raw_writeq(IMR_IP3_VAL, IOADDR(A_BCM1480_IMR_REGISTER(cpu, R_BCM1480_IMR_INTERRUPT_MAP_BASE_H) +
 366                                                  (K_BCM1480_INT_MBOX_0_0 << 3)));
 367         }
 368
 369
 370         /* Clear the mailboxes.  The firmware may leave them dirty */
 371         for (cpu = 0; cpu < 4; cpu++) {
 372                 __raw_writeq(0xffffffffffffffffULL,
 373                              IOADDR(A_BCM1480_IMR_REGISTER(cpu, R_BCM1480_IMR_MAILBOX_0_CLR_CPU)));
 374                 __raw_writeq(0xffffffffffffffffULL,
 375                              IOADDR(A_BCM1480_IMR_REGISTER(cpu, R_BCM1480_IMR_MAILBOX_1_CLR_CPU)));
 376         }
 377
 378
 379         /* Mask everything except the high 16 bit of mailbox_0 registers for all cpus */
 380         tmp = ~((u64) 0) ^ ( (((u64) 1) << K_BCM1480_INT_MBOX_0_0));
 381         for (cpu = 0; cpu < 4; cpu++) {
 382                 __raw_writeq(tmp, IOADDR(A_BCM1480_IMR_REGISTER(cpu, R_BCM1480_IMR_INTERRUPT_MASK_H)));
 383         }
 384         tmp = ~((u64) 0);
 385         for (cpu = 0; cpu < 4; cpu++) {
 386                 __raw_writeq(tmp, IOADDR(A_BCM1480_IMR_REGISTER(cpu, R_BCM1480_IMR_INTERRUPT_MASK_L)));
 387         }
 388
 389         bcm1480_steal_irq(K_BCM1480_INT_MBOX_0_0);
 390
 391         /*
 392          * Note that the timer interrupts are also mapped, but this is
 393          * done in bcm1480_time_init().  Also, the profiling driver
 394          * does its own management of IP7.
 395          */
 396
 397 #ifdef CONFIG_KGDB
 398         imask |= STATUSF_IP6;
 399 #endif
 400         /* Enable necessary IPs, disable the rest */
 401         change_c0_status(ST0_IM, imask);
 402
 403 #ifdef CONFIG_KGDB
 404         if (kgdb_flag) {
 405                 kgdb_irq = K_BCM1480_INT_UART_0 + kgdb_port;
 406
 407 #ifdef CONFIG_SIBYTE_SB1250_DUART
 408                 sb1250_duart_present[kgdb_port] = 0;
 409 #endif
 410                 /* Setup uart 1 settings, mapper */
 411                 /* QQQ FIXME */
 412                 __raw_writeq(M_DUART_IMR_BRK, IO_SPACE_BASE + A_DUART_IMRREG(kgdb_port));
 413
 414                 bcm1480_steal_irq(kgdb_irq);
 415                 __raw_writeq(IMR_IP6_VAL,
 416                              IO_SPACE_BASE + A_BCM1480_IMR_REGISTER(0, R_BCM1480_IMR_INTERRUPT_MAP_BASE_H) +
 417                              (kgdb_irq<<3));
 418                 bcm1480_unmask_irq(0, kgdb_irq);
 419
 420 #ifdef CONFIG_GDB_CONSOLE
 421                 register_gdb_console();
 422 #endif
 423                 printk("Waiting for GDB on UART port %d\n", kgdb_port);
 424                 set_debug_traps();
 425                 breakpoint();
 426         }
 427 #endif
 428 }
 429
 430 #ifdef CONFIG_KGDB
 431
 432 #include <linux/delay.h>
 433
 434 #define duart_out(reg, val)     csr_out32(val, IOADDR(A_DUART_CHANREG(kgdb_port,reg)))
 435 #define duart_in(reg)           csr_in32(IOADDR(A_DUART_CHANREG(kgdb_port,reg)))
 436
 437 static void bcm1480_kgdb_interrupt(void)
 438 {
 439         /*
 440          * Clear break-change status (allow some time for the remote
 441          * host to stop the break, since we would see another
 442          * interrupt on the end-of-break too)
 443          */
 444         kstat.irqs[smp_processor_id()][kgdb_irq]++;
 445         mdelay(500);
 446         duart_out(R_DUART_CMD, V_DUART_MISC_CMD_RESET_BREAK_INT |
 447                                 M_DUART_RX_EN | M_DUART_TX_EN);
 448         set_async_breakpoint(&get_irq_regs()->cp0_epc);
 449 }
 450
 451 #endif  /* CONFIG_KGDB */
 452
 453 extern void bcm1480_timer_interrupt(void);
 454 extern void bcm1480_mailbox_interrupt(void);
 455
 456 asmlinkage void plat_irq_dispatch(void)
 457 {
 458         unsigned int pending;
 459
 460 #ifdef CONFIG_SIBYTE_BCM1480_PROF
 461         /* Set compare to count to silence count/compare timer interrupts */
 462         write_c0_compare(read_c0_count());
 463 #endif
 464
 465         pending = read_c0_cause() & read_c0_status();
 466
 467 #ifdef CONFIG_SIBYTE_BCM1480_PROF
 468         if (pending & CAUSEF_IP7)       /* Cpu performance counter interrupt */
 469                 sbprof_cpu_intr();
 470         else
 471 #endif
 472
 473         if (pending & CAUSEF_IP4)
 474                 bcm1480_timer_interrupt();
 475
 476 #ifdef CONFIG_SMP
 477         else if (pending & CAUSEF_IP3)
 478                 bcm1480_mailbox_interrupt();
 479 #endif
 480
 481 #ifdef CONFIG_KGDB
 482         else if (pending & CAUSEF_IP6)
 483                 bcm1480_kgdb_interrupt();               /* KGDB (uart 1) */
 484 #endif
 485
 486         else if (pending & CAUSEF_IP2) {
 487                 unsigned long long mask_h, mask_l;
 488                 unsigned long base;
 489
 490                 /*
 491                  * Default...we've hit an IP[2] interrupt, which means we've
 492                  * got to check the 1480 interrupt registers to figure out what
 493                  * to do.  Need to detect which CPU we're on, now that
 494                  * smp_affinity is supported.
 495                  */
 496                 base = A_BCM1480_IMR_MAPPER(smp_processor_id());
 497                 mask_h = __raw_readq(
 498                         IOADDR(base + R_BCM1480_IMR_INTERRUPT_STATUS_BASE_H));
 499                 mask_l = __raw_readq(
 500                         IOADDR(base + R_BCM1480_IMR_INTERRUPT_STATUS_BASE_L));
 501
 502                 if (mask_h) {
 503                         if (mask_h ^ 1)
 504                                 do_IRQ(fls64(mask_h) - 1);
 505                         else
 506                                 do_IRQ(63 + fls64(mask_l));
 507                 }
 508         }
 509 }