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/config.h>
  19 #include <linux/kernel.h>
  20 #include <linux/init.h>
  21 #include <linux/linkage.h>
  22 #include <linux/interrupt.h>
  23 #include <linux/spinlock.h>
  24 #include <linux/mm.h>
  25 #include <linux/slab.h>
  26 #include <linux/kernel_stat.h>
  27
  28 #include <asm/errno.h>
  29 #include <asm/signal.h>
  30 #include <asm/system.h>
  31 #include <asm/ptrace.h>
  32 #include <asm/io.h>
  33
  34 #include <asm/sibyte/bcm1480_regs.h>
  35 #include <asm/sibyte/bcm1480_int.h>
  36 #include <asm/sibyte/bcm1480_scd.h>
  37
  38 #include <asm/sibyte/sb1250_uart.h>
  39 #include <asm/sibyte/sb1250.h>
  40
  41 /*
  42  * These are the routines that handle all the low level interrupt stuff.
  43  * Actions handled here are: initialization of the interrupt map, requesting of
  44  * interrupt lines by handlers, dispatching if interrupts to handlers, probing
  45  * for interrupt lines
  46  */
  47
  48
  49 #define shutdown_bcm1480_irq    disable_bcm1480_irq
  50 static void end_bcm1480_irq(unsigned int irq);
  51 static void enable_bcm1480_irq(unsigned int irq);
  52 static void disable_bcm1480_irq(unsigned int irq);
  53 static unsigned int startup_bcm1480_irq(unsigned int irq);
  54 static void ack_bcm1480_irq(unsigned int irq);
  55 #ifdef CONFIG_SMP
  56 static void bcm1480_set_affinity(unsigned int irq, cpumask_t mask);
  57 #endif
  58
  59 #ifdef CONFIG_PCI
  60 extern unsigned long ht_eoi_space;
  61 #endif
  62
  63 #ifdef CONFIG_KGDB
  64 #include <asm/gdb-stub.h>
  65 extern void breakpoint(void);
  66 static int kgdb_irq;
  67 #ifdef CONFIG_GDB_CONSOLE
  68 extern void register_gdb_console(void);
  69 #endif
  70
  71 /* kgdb is on when configured.  Pass "nokgdb" kernel arg to turn it off */
  72 static int kgdb_flag = 1;
  73 static int __init nokgdb(char *str)
  74 {
  75         kgdb_flag = 0;
  76         return 1;
  77 }
  78 __setup("nokgdb", nokgdb);
  79
  80 /* Default to UART1 */
  81 int kgdb_port = 1;
  82 #ifdef CONFIG_SIBYTE_SB1250_DUART
  83 extern char sb1250_duart_present[];
  84 #endif
  85 #endif
  86
  87 static struct hw_interrupt_type bcm1480_irq_type = {
  88         .typename = "BCM1480-IMR",
  89         .startup = startup_bcm1480_irq,
  90         .shutdown = shutdown_bcm1480_irq,
  91         .enable = enable_bcm1480_irq,
  92         .disable = disable_bcm1480_irq,
  93         .ack = ack_bcm1480_irq,
  94         .end = end_bcm1480_irq,
  95 #ifdef CONFIG_SMP
  96         .set_affinity = bcm1480_set_affinity
  97 #endif
  98 };
  99
 100 /* Store the CPU id (not the logical number) */
 101 int bcm1480_irq_owner[BCM1480_NR_IRQS];
 102
 103 DEFINE_SPINLOCK(bcm1480_imr_lock);
 104
 105 void bcm1480_mask_irq(int cpu, int irq)
 106 {
 107         unsigned long flags;
 108         u64 cur_ints,hl_spacing;
 109
 110         spin_lock_irqsave(&bcm1480_imr_lock, flags);
 111         hl_spacing = 0;
 112         if ((irq >= BCM1480_NR_IRQS_HALF) && (irq <= BCM1480_NR_IRQS)) {
 113                 hl_spacing = BCM1480_IMR_HL_SPACING;
 114                 irq -= BCM1480_NR_IRQS_HALF;
 115         }
 116         cur_ints = ____raw_readq(IOADDR(A_BCM1480_IMR_MAPPER(cpu) + R_BCM1480_IMR_INTERRUPT_MASK_H + hl_spacing));
 117         cur_ints |= (((u64) 1) << irq);
 118         ____raw_writeq(cur_ints, IOADDR(A_BCM1480_IMR_MAPPER(cpu) + R_BCM1480_IMR_INTERRUPT_MASK_H + hl_spacing));
 119         spin_unlock_irqrestore(&bcm1480_imr_lock, flags);
 120 }
 121
 122 void bcm1480_unmask_irq(int cpu, int irq)
 123 {
 124         unsigned long flags;
 125         u64 cur_ints,hl_spacing;
 126
 127         spin_lock_irqsave(&bcm1480_imr_lock, flags);
 128         hl_spacing = 0;
 129         if ((irq >= BCM1480_NR_IRQS_HALF) && (irq <= BCM1480_NR_IRQS)) {
 130                 hl_spacing = BCM1480_IMR_HL_SPACING;
 131                 irq -= BCM1480_NR_IRQS_HALF;
 132         }
 133         cur_ints = ____raw_readq(IOADDR(A_BCM1480_IMR_MAPPER(cpu) + R_BCM1480_IMR_INTERRUPT_MASK_H + hl_spacing));
 134         cur_ints &= ~(((u64) 1) << irq);
 135         ____raw_writeq(cur_ints, IOADDR(A_BCM1480_IMR_MAPPER(cpu) + R_BCM1480_IMR_INTERRUPT_MASK_H + hl_spacing));
 136         spin_unlock_irqrestore(&bcm1480_imr_lock, flags);
 137 }
 138
 139 #ifdef CONFIG_SMP
 140 static void bcm1480_set_affinity(unsigned int irq, cpumask_t mask)
 141 {
 142         int i = 0, old_cpu, cpu, int_on, k;
 143         u64 cur_ints;
 144         irq_desc_t *desc = irq_desc + irq;
 145         unsigned long flags;
 146         unsigned int irq_dirty;
 147
 148         i = first_cpu(mask);
 149         if (next_cpu(i, mask) <= NR_CPUS) {
 150                 printk("attempted to set irq affinity for irq %d to multiple CPUs\n", irq);
 151                 return;
 152         }
 153
 154         /* Convert logical CPU to physical CPU */
 155         cpu = cpu_logical_map(i);
 156
 157         /* Protect against other affinity changers and IMR manipulation */
 158         spin_lock_irqsave(&desc->lock, flags);
 159         spin_lock(&bcm1480_imr_lock);
 160
 161         /* Swizzle each CPU's IMR (but leave the IP selection alone) */
 162         old_cpu = bcm1480_irq_owner[irq];
 163         irq_dirty = irq;
 164         if ((irq_dirty >= BCM1480_NR_IRQS_HALF) && (irq_dirty <= BCM1480_NR_IRQS)) {
 165                 irq_dirty -= BCM1480_NR_IRQS_HALF;
 166         }
 167
 168         for (k=0; k<2; k++) { /* Loop through high and low interrupt mask register */
 169                 cur_ints = ____raw_readq(IOADDR(A_BCM1480_IMR_MAPPER(old_cpu) + R_BCM1480_IMR_INTERRUPT_MASK_H + (k*BCM1480_IMR_HL_SPACING)));
 170                 int_on = !(cur_ints & (((u64) 1) << irq_dirty));
 171                 if (int_on) {
 172                         /* If it was on, mask it */
 173                         cur_ints |= (((u64) 1) << irq_dirty);
 174                         ____raw_writeq(cur_ints, IOADDR(A_BCM1480_IMR_MAPPER(old_cpu) + R_BCM1480_IMR_INTERRUPT_MASK_H + (k*BCM1480_IMR_HL_SPACING)));
 175                 }
 176                 bcm1480_irq_owner[irq] = cpu;
 177                 if (int_on) {
 178                         /* unmask for the new CPU */
 179                         cur_ints = ____raw_readq(IOADDR(A_BCM1480_IMR_MAPPER(cpu) + R_BCM1480_IMR_INTERRUPT_MASK_H + (k*BCM1480_IMR_HL_SPACING)));
 180                         cur_ints &= ~(((u64) 1) << irq_dirty);
 181                         ____raw_writeq(cur_ints, IOADDR(A_BCM1480_IMR_MAPPER(cpu) + R_BCM1480_IMR_INTERRUPT_MASK_H + (k*BCM1480_IMR_HL_SPACING)));
 182                 }
 183         }
 184         spin_unlock(&bcm1480_imr_lock);
 185         spin_unlock_irqrestore(&desc->lock, flags);
 186 }
 187 #endif
 188
 189
 190 /* Defined in arch/mips/sibyte/bcm1480/irq_handler.S */
 191 extern void bcm1480_irq_handler(void);
 192
 193 /*****************************************************************************/
 194
 195 static unsigned int startup_bcm1480_irq(unsigned int irq)
 196 {
 197         bcm1480_unmask_irq(bcm1480_irq_owner[irq], irq);
 198
 199         return 0;               /* never anything pending */
 200 }
 201
 202
 203 static void disable_bcm1480_irq(unsigned int irq)
 204 {
 205         bcm1480_mask_irq(bcm1480_irq_owner[irq], irq);
 206 }
 207
 208 static void enable_bcm1480_irq(unsigned int irq)
 209 {
 210         bcm1480_unmask_irq(bcm1480_irq_owner[irq], irq);
 211 }
 212
 213
 214 static void ack_bcm1480_irq(unsigned int irq)
 215 {
 216         u64 pending;
 217         unsigned int irq_dirty;
 218         int k;
 219
 220         /*
 221          * If the interrupt was an HT interrupt, now is the time to
 222          * clear it.  NOTE: we assume the HT bridge was set up to
 223          * deliver the interrupts to all CPUs (which makes affinity
 224          * changing easier for us)
 225          */
 226         irq_dirty = irq;
 227         if ((irq_dirty >= BCM1480_NR_IRQS_HALF) && (irq_dirty <= BCM1480_NR_IRQS)) {
 228                 irq_dirty -= BCM1480_NR_IRQS_HALF;
 229         }
 230         for (k=0; k<2; k++) { /* Loop through high and low LDT interrupts */
 231                 pending = __raw_readq(IOADDR(A_BCM1480_IMR_REGISTER(bcm1480_irq_owner[irq],
 232                                                 R_BCM1480_IMR_LDT_INTERRUPT_H + (k*BCM1480_IMR_HL_SPACING))));
 233                 pending &= ((u64)1 << (irq_dirty));
 234                 if (pending) {
 235 #ifdef CONFIG_SMP
 236                         int i;
 237                         for (i=0; i<NR_CPUS; i++) {
 238                                 /*
 239                                  * Clear for all CPUs so an affinity switch
 240                                  * doesn't find an old status
 241                                  */
 242                                 __raw_writeq(pending, IOADDR(A_BCM1480_IMR_REGISTER(cpu_logical_map(i),
 243                                                                 R_BCM1480_IMR_LDT_INTERRUPT_CLR_H + (k*BCM1480_IMR_HL_SPACING))));
 244                         }
 245 #else
 246                         __raw_writeq(pending, IOADDR(A_BCM1480_IMR_REGISTER(0, R_BCM1480_IMR_LDT_INTERRUPT_CLR_H + (k*BCM1480_IMR_HL_SPACING))));
 247 #endif
 248
 249                         /*
 250                          * Generate EOI.  For Pass 1 parts, EOI is a nop.  For
 251                          * Pass 2, the LDT world may be edge-triggered, but
 252                          * this EOI shouldn't hurt.  If they are
 253                          * level-sensitive, the EOI is required.
 254                          */
 255 #ifdef CONFIG_PCI
 256                         if (ht_eoi_space)
 257                                 *(uint32_t *)(ht_eoi_space+(irq<<16)+(7<<2)) = 0;
 258 #endif
 259                 }
 260         }
 261         bcm1480_mask_irq(bcm1480_irq_owner[irq], irq);
 262 }
 263
 264
 265 static void end_bcm1480_irq(unsigned int irq)
 266 {
 267         if (!(irq_desc[irq].status & (IRQ_DISABLED | IRQ_INPROGRESS))) {
 268                 bcm1480_unmask_irq(bcm1480_irq_owner[irq], irq);
 269         }
 270 }
 271
 272
 273 void __init init_bcm1480_irqs(void)
 274 {
 275         int i;
 276
 277         for (i = 0; i < NR_IRQS; i++) {
 278                 irq_desc[i].status = IRQ_DISABLED;
 279                 irq_desc[i].action = 0;
 280                 irq_desc[i].depth = 1;
 281                 if (i < BCM1480_NR_IRQS) {
 282                         irq_desc[i].handler = &bcm1480_irq_type;
 283                         bcm1480_irq_owner[i] = 0;
 284                 } else {
 285                         irq_desc[i].handler = &no_irq_type;
 286                 }
 287         }
 288 }
 289
 290
 291 static irqreturn_t bcm1480_dummy_handler(int irq, void *dev_id,
 292         struct pt_regs *regs)
 293 {
 294         return IRQ_NONE;
 295 }
 296
 297 static struct irqaction bcm1480_dummy_action = {
 298         .handler = bcm1480_dummy_handler,
 299         .flags   = 0,
 300         .mask    = CPU_MASK_NONE,
 301         .name    = "bcm1480-private",
 302         .next    = NULL,
 303         .dev_id  = 0
 304 };
 305
 306 int bcm1480_steal_irq(int irq)
 307 {
 308         irq_desc_t *desc = irq_desc + irq;
 309         unsigned long flags;
 310         int retval = 0;
 311
 312         if (irq >= BCM1480_NR_IRQS)
 313                 return -EINVAL;
 314
 315         spin_lock_irqsave(&desc->lock,flags);
 316         /* Don't allow sharing at all for these */
 317         if (desc->action != NULL)
 318                 retval = -EBUSY;
 319         else {
 320                 desc->action = &bcm1480_dummy_action;
 321                 desc->depth = 0;
 322         }
 323         spin_unlock_irqrestore(&desc->lock,flags);
 324         return 0;
 325 }
 326
 327 /*
 328  *  init_IRQ is called early in the boot sequence from init/main.c.  It
 329  *  is responsible for setting up the interrupt mapper and installing the
 330  *  handler that will be responsible for dispatching interrupts to the
 331  *  "right" place.
 332  */
 333 /*
 334  * For now, map all interrupts to IP[2].  We could save
 335  * some cycles by parceling out system interrupts to different
 336  * IP lines, but keep it simple for bringup.  We'll also direct
 337  * all interrupts to a single CPU; we should probably route
 338  * PCI and LDT to one cpu and everything else to the other
 339  * to balance the load a bit.
 340  *
 341  * On the second cpu, everything is set to IP5, which is
 342  * ignored, EXCEPT the mailbox interrupt.  That one is
 343  * set to IP[2] so it is handled.  This is needed so we
 344  * can do cross-cpu function calls, as requred by SMP
 345  */
 346
 347 #define IMR_IP2_VAL     K_BCM1480_INT_MAP_I0
 348 #define IMR_IP3_VAL     K_BCM1480_INT_MAP_I1
 349 #define IMR_IP4_VAL     K_BCM1480_INT_MAP_I2
 350 #define IMR_IP5_VAL     K_BCM1480_INT_MAP_I3
 351 #define IMR_IP6_VAL     K_BCM1480_INT_MAP_I4
 352
 353 void __init arch_init_irq(void)
 354 {
 355
 356         unsigned int i, cpu;
 357         u64 tmp;
 358         unsigned int imask = STATUSF_IP4 | STATUSF_IP3 | STATUSF_IP2 |
 359                 STATUSF_IP1 | STATUSF_IP0;
 360
 361         /* Default everything to IP2 */
 362         /* Start with _high registers which has no bit 0 interrupt source */
 363         for (i = 1; i < BCM1480_NR_IRQS_HALF; i++) {    /* was I0 */
 364                 for (cpu = 0; cpu < 4; cpu++) {
 365                         __raw_writeq(IMR_IP2_VAL,
 366                                      IOADDR(A_BCM1480_IMR_REGISTER(cpu,
 367                                                                    R_BCM1480_IMR_INTERRUPT_MAP_BASE_H) + (i << 3)));
 368                 }
 369         }
 370
 371         /* Now do _low registers */
 372         for (i = 0; i < BCM1480_NR_IRQS_HALF; i++) {
 373                 for (cpu = 0; cpu < 4; cpu++) {
 374                         __raw_writeq(IMR_IP2_VAL,
 375                                      IOADDR(A_BCM1480_IMR_REGISTER(cpu,
 376                                                                    R_BCM1480_IMR_INTERRUPT_MAP_BASE_L) + (i << 3)));
 377                 }
 378         }
 379
 380         init_bcm1480_irqs();
 381
 382         /*
 383          * Map the high 16 bits of mailbox_0 registers to IP[3], for
 384          * inter-cpu messages
 385          */
 386         /* Was I1 */
 387         for (cpu = 0; cpu < 4; cpu++) {
 388                 __raw_writeq(IMR_IP3_VAL, IOADDR(A_BCM1480_IMR_REGISTER(cpu, R_BCM1480_IMR_INTERRUPT_MAP_BASE_H) +
 389                                                  (K_BCM1480_INT_MBOX_0_0 << 3)));
 390         }
 391
 392
 393         /* Clear the mailboxes.  The firmware may leave them dirty */
 394         for (cpu = 0; cpu < 4; cpu++) {
 395                 __raw_writeq(0xffffffffffffffffULL,
 396                              IOADDR(A_BCM1480_IMR_REGISTER(cpu, R_BCM1480_IMR_MAILBOX_0_CLR_CPU)));
 397                 __raw_writeq(0xffffffffffffffffULL,
 398                              IOADDR(A_BCM1480_IMR_REGISTER(cpu, R_BCM1480_IMR_MAILBOX_1_CLR_CPU)));
 399         }
 400
 401
 402         /* Mask everything except the high 16 bit of mailbox_0 registers for all cpus */
 403         tmp = ~((u64) 0) ^ ( (((u64) 1) << K_BCM1480_INT_MBOX_0_0));
 404         for (cpu = 0; cpu < 4; cpu++) {
 405                 __raw_writeq(tmp, IOADDR(A_BCM1480_IMR_REGISTER(cpu, R_BCM1480_IMR_INTERRUPT_MASK_H)));
 406         }
 407         tmp = ~((u64) 0);
 408         for (cpu = 0; cpu < 4; cpu++) {
 409                 __raw_writeq(tmp, IOADDR(A_BCM1480_IMR_REGISTER(cpu, R_BCM1480_IMR_INTERRUPT_MASK_L)));
 410         }
 411
 412         bcm1480_steal_irq(K_BCM1480_INT_MBOX_0_0);
 413
 414         /*
 415          * Note that the timer interrupts are also mapped, but this is
 416          * done in bcm1480_time_init().  Also, the profiling driver
 417          * does its own management of IP7.
 418          */
 419
 420 #ifdef CONFIG_KGDB
 421         imask |= STATUSF_IP6;
 422 #endif
 423         /* Enable necessary IPs, disable the rest */
 424         change_c0_status(ST0_IM, imask);
 425         set_except_vector(0, bcm1480_irq_handler);
 426
 427 #ifdef CONFIG_KGDB
 428         if (kgdb_flag) {
 429                 kgdb_irq = K_BCM1480_INT_UART_0 + kgdb_port;
 430
 431 #ifdef CONFIG_SIBYTE_SB1250_DUART
 432                 sb1250_duart_present[kgdb_port] = 0;
 433 #endif
 434                 /* Setup uart 1 settings, mapper */
 435                 /* QQQ FIXME */
 436                 __raw_writeq(M_DUART_IMR_BRK, IO_SPACE_BASE + A_DUART_IMRREG(kgdb_port));
 437
 438                 bcm1480_steal_irq(kgdb_irq);
 439                 __raw_writeq(IMR_IP6_VAL,
 440                              IO_SPACE_BASE + A_BCM1480_IMR_REGISTER(0, R_BCM1480_IMR_INTERRUPT_MAP_BASE_H) +
 441                              (kgdb_irq<<3));
 442                 bcm1480_unmask_irq(0, kgdb_irq);
 443
 444 #ifdef CONFIG_GDB_CONSOLE
 445                 register_gdb_console();
 446 #endif
 447                 prom_printf("Waiting for GDB on UART port %d\n", kgdb_port);
 448                 set_debug_traps();
 449                 breakpoint();
 450         }
 451 #endif
 452 }
 453
 454 #ifdef CONFIG_KGDB
 455
 456 #include <linux/delay.h>
 457
 458 #define duart_out(reg, val)     csr_out32(val, IOADDR(A_DUART_CHANREG(kgdb_port,reg)))
 459 #define duart_in(reg)           csr_in32(IOADDR(A_DUART_CHANREG(kgdb_port,reg)))
 460
 461 void bcm1480_kgdb_interrupt(struct pt_regs *regs)
 462 {
 463         /*
 464          * Clear break-change status (allow some time for the remote
 465          * host to stop the break, since we would see another
 466          * interrupt on the end-of-break too)
 467          */
 468         kstat.irqs[smp_processor_id()][kgdb_irq]++;
 469         mdelay(500);
 470         duart_out(R_DUART_CMD, V_DUART_MISC_CMD_RESET_BREAK_INT |
 471                                 M_DUART_RX_EN | M_DUART_TX_EN);
 472         set_async_breakpoint(&regs->cp0_epc);
 473 }
 474
 475 #endif  /* CONFIG_KGDB */