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_SERIAL_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, hl_spacing;
 104         u64 cur_ints;
 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, hl_spacing;
 121         u64 cur_ints;
 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  *  init_IRQ is called early in the boot sequence from init/main.c.  It
 270  *  is responsible for setting up the interrupt mapper and installing the
 271  *  handler that will be responsible for dispatching interrupts to the
 272  *  "right" place.
 273  */
 274 /*
 275  * For now, map all interrupts to IP[2].  We could save
 276  * some cycles by parceling out system interrupts to different
 277  * IP lines, but keep it simple for bringup.  We'll also direct
 278  * all interrupts to a single CPU; we should probably route
 279  * PCI and LDT to one cpu and everything else to the other
 280  * to balance the load a bit.
 281  *
 282  * On the second cpu, everything is set to IP5, which is
 283  * ignored, EXCEPT the mailbox interrupt.  That one is
 284  * set to IP[2] so it is handled.  This is needed so we
 285  * can do cross-cpu function calls, as requred by SMP
 286  */
 287
 288 #define IMR_IP2_VAL     K_BCM1480_INT_MAP_I0
 289 #define IMR_IP3_VAL     K_BCM1480_INT_MAP_I1
 290 #define IMR_IP4_VAL     K_BCM1480_INT_MAP_I2
 291 #define IMR_IP5_VAL     K_BCM1480_INT_MAP_I3
 292 #define IMR_IP6_VAL     K_BCM1480_INT_MAP_I4
 293
 294 void __init arch_init_irq(void)
 295 {
 296         unsigned int i, cpu;
 297         u64 tmp;
 298         unsigned int imask = STATUSF_IP4 | STATUSF_IP3 | STATUSF_IP2 |
 299                 STATUSF_IP1 | STATUSF_IP0;
 300
 301         /* Default everything to IP2 */
 302         /* Start with _high registers which has no bit 0 interrupt source */
 303         for (i = 1; i < BCM1480_NR_IRQS_HALF; i++) {    /* was I0 */
 304                 for (cpu = 0; cpu < 4; cpu++) {
 305                         __raw_writeq(IMR_IP2_VAL,
 306                                      IOADDR(A_BCM1480_IMR_REGISTER(cpu,
 307                                                                    R_BCM1480_IMR_INTERRUPT_MAP_BASE_H) + (i << 3)));
 308                 }
 309         }
 310
 311         /* Now do _low registers */
 312         for (i = 0; i < BCM1480_NR_IRQS_HALF; i++) {
 313                 for (cpu = 0; cpu < 4; cpu++) {
 314                         __raw_writeq(IMR_IP2_VAL,
 315                                      IOADDR(A_BCM1480_IMR_REGISTER(cpu,
 316                                                                    R_BCM1480_IMR_INTERRUPT_MAP_BASE_L) + (i << 3)));
 317                 }
 318         }
 319
 320         init_bcm1480_irqs();
 321
 322         /*
 323          * Map the high 16 bits of mailbox_0 registers to IP[3], for
 324          * inter-cpu messages
 325          */
 326         /* Was I1 */
 327         for (cpu = 0; cpu < 4; cpu++) {
 328                 __raw_writeq(IMR_IP3_VAL, IOADDR(A_BCM1480_IMR_REGISTER(cpu, R_BCM1480_IMR_INTERRUPT_MAP_BASE_H) +
 329                                                  (K_BCM1480_INT_MBOX_0_0 << 3)));
 330         }
 331
 332
 333         /* Clear the mailboxes.  The firmware may leave them dirty */
 334         for (cpu = 0; cpu < 4; cpu++) {
 335                 __raw_writeq(0xffffffffffffffffULL,
 336                              IOADDR(A_BCM1480_IMR_REGISTER(cpu, R_BCM1480_IMR_MAILBOX_0_CLR_CPU)));
 337                 __raw_writeq(0xffffffffffffffffULL,
 338                              IOADDR(A_BCM1480_IMR_REGISTER(cpu, R_BCM1480_IMR_MAILBOX_1_CLR_CPU)));
 339         }
 340
 341
 342         /* Mask everything except the high 16 bit of mailbox_0 registers for all cpus */
 343         tmp = ~((u64) 0) ^ ( (((u64) 1) << K_BCM1480_INT_MBOX_0_0));
 344         for (cpu = 0; cpu < 4; cpu++) {
 345                 __raw_writeq(tmp, IOADDR(A_BCM1480_IMR_REGISTER(cpu, R_BCM1480_IMR_INTERRUPT_MASK_H)));
 346         }
 347         tmp = ~((u64) 0);
 348         for (cpu = 0; cpu < 4; cpu++) {
 349                 __raw_writeq(tmp, IOADDR(A_BCM1480_IMR_REGISTER(cpu, R_BCM1480_IMR_INTERRUPT_MASK_L)));
 350         }
 351
 352         /*
 353          * Note that the timer interrupts are also mapped, but this is
 354          * done in bcm1480_time_init().  Also, the profiling driver
 355          * does its own management of IP7.
 356          */
 357
 358 #ifdef CONFIG_KGDB
 359         imask |= STATUSF_IP6;
 360 #endif
 361         /* Enable necessary IPs, disable the rest */
 362         change_c0_status(ST0_IM, imask);
 363
 364 #ifdef CONFIG_KGDB
 365         if (kgdb_flag) {
 366                 kgdb_irq = K_BCM1480_INT_UART_0 + kgdb_port;
 367
 368 #ifdef CONFIG_SERIAL_SB1250_DUART
 369                 sb1250_duart_present[kgdb_port] = 0;
 370 #endif
 371                 /* Setup uart 1 settings, mapper */
 372                 /* QQQ FIXME */
 373                 __raw_writeq(M_DUART_IMR_BRK, IOADDR(A_DUART_IMRREG(kgdb_port)));
 374
 375                 __raw_writeq(IMR_IP6_VAL,
 376                              IOADDR(A_BCM1480_IMR_REGISTER(0, R_BCM1480_IMR_INTERRUPT_MAP_BASE_H) +
 377                              (kgdb_irq << 3)));
 378                 bcm1480_unmask_irq(0, kgdb_irq);
 379
 380 #ifdef CONFIG_GDB_CONSOLE
 381                 register_gdb_console();
 382 #endif
 383                 printk("Waiting for GDB on UART port %d\n", kgdb_port);
 384                 set_debug_traps();
 385                 breakpoint();
 386         }
 387 #endif
 388 }
 389
 390 #ifdef CONFIG_KGDB
 391
 392 #include <linux/delay.h>
 393
 394 #define duart_out(reg, val)     csr_out32(val, IOADDR(A_DUART_CHANREG(kgdb_port, reg)))
 395 #define duart_in(reg)           csr_in32(IOADDR(A_DUART_CHANREG(kgdb_port, reg)))
 396
 397 static void bcm1480_kgdb_interrupt(void)
 398 {
 399         /*
 400          * Clear break-change status (allow some time for the remote
 401          * host to stop the break, since we would see another
 402          * interrupt on the end-of-break too)
 403          */
 404         kstat.irqs[smp_processor_id()][kgdb_irq]++;
 405         mdelay(500);
 406         duart_out(R_DUART_CMD, V_DUART_MISC_CMD_RESET_BREAK_INT |
 407                                 M_DUART_RX_EN | M_DUART_TX_EN);
 408         set_async_breakpoint(&get_irq_regs()->cp0_epc);
 409 }
 410
 411 #endif  /* CONFIG_KGDB */
 412
 413 extern void bcm1480_mailbox_interrupt(void);
 414
 415 static inline void dispatch_ip2(void)
 416 {
 417         unsigned long long mask_h, mask_l;
 418         unsigned int cpu = smp_processor_id();
 419         unsigned long base;
 420
 421         /*
 422          * Default...we've hit an IP[2] interrupt, which means we've got to
 423          * check the 1480 interrupt registers to figure out what to do.  Need
 424          * to detect which CPU we're on, now that smp_affinity is supported.
 425          */
 426         base = A_BCM1480_IMR_MAPPER(cpu);
 427         mask_h = __raw_readq(
 428                 IOADDR(base + R_BCM1480_IMR_INTERRUPT_STATUS_BASE_H));
 429         mask_l = __raw_readq(
 430                 IOADDR(base + R_BCM1480_IMR_INTERRUPT_STATUS_BASE_L));
 431
 432         if (mask_h) {
 433                 if (mask_h ^ 1)
 434                         do_IRQ(fls64(mask_h) - 1);
 435                 else if (mask_l)
 436                         do_IRQ(63 + fls64(mask_l));
 437         }
 438 }
 439
 440 asmlinkage void plat_irq_dispatch(void)
 441 {
 442         unsigned int cpu = smp_processor_id();
 443         unsigned int pending;
 444
 445 #ifdef CONFIG_SIBYTE_BCM1480_PROF
 446         /* Set compare to count to silence count/compare timer interrupts */
 447         write_c0_compare(read_c0_count());
 448 #endif
 449
 450         pending = read_c0_cause() & read_c0_status();
 451
 452 #ifdef CONFIG_SIBYTE_BCM1480_PROF
 453         if (pending & CAUSEF_IP7)       /* Cpu performance counter interrupt */
 454                 sbprof_cpu_intr();
 455         else
 456 #endif
 457
 458         if (pending & CAUSEF_IP4)
 459                 do_IRQ(K_BCM1480_INT_TIMER_0 + cpu);
 460 #ifdef CONFIG_SMP
 461         else if (pending & CAUSEF_IP3)
 462                 bcm1480_mailbox_interrupt();
 463 #endif
 464
 465 #ifdef CONFIG_KGDB
 466         else if (pending & CAUSEF_IP6)
 467                 bcm1480_kgdb_interrupt();               /* KGDB (uart 1) */
 468 #endif
 469
 470         else if (pending & CAUSEF_IP2)
 471                 dispatch_ip2();
 472 }