arch/mips/sibyte/sb1250/irq.c

   1 /*
   2  * Copyright (C) 2000, 2001, 2002, 2003 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/smp.h>
  25 #include <linux/mm.h>
  26 #include <linux/slab.h>
  27 #include <linux/kernel_stat.h>
  28
  29 #include <asm/errno.h>
  30 #include <asm/signal.h>
  31 #include <asm/system.h>
  32 #include <asm/ptrace.h>
  33 #include <asm/io.h>
  34
  35 #include <asm/sibyte/sb1250_regs.h>
  36 #include <asm/sibyte/sb1250_int.h>
  37 #include <asm/sibyte/sb1250_uart.h>
  38 #include <asm/sibyte/sb1250_scd.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_sb1250_irq     disable_sb1250_irq
  50 static void end_sb1250_irq(unsigned int irq);
  51 static void enable_sb1250_irq(unsigned int irq);
  52 static void disable_sb1250_irq(unsigned int irq);
  53 static unsigned int startup_sb1250_irq(unsigned int irq);
  54 static void ack_sb1250_irq(unsigned int irq);
  55 #ifdef CONFIG_SMP
  56 static void sb1250_set_affinity(unsigned int irq, unsigned long mask);
  57 #endif
  58
  59 #ifdef CONFIG_SIBYTE_HAS_LDT
  60 extern unsigned long ldt_eoi_space;
  61 #endif
  62
  63 #ifdef CONFIG_KGDB
  64 static int kgdb_irq;
  65
  66 /* Default to UART1 */
  67 int kgdb_port = 1;
  68 #ifdef CONFIG_SIBYTE_SB1250_DUART
  69 extern char sb1250_duart_present[];
  70 #endif
  71 #endif
  72
  73 static struct hw_interrupt_type sb1250_irq_type = {
  74         "SB1250-IMR",
  75         startup_sb1250_irq,
  76         shutdown_sb1250_irq,
  77         enable_sb1250_irq,
  78         disable_sb1250_irq,
  79         ack_sb1250_irq,
  80         end_sb1250_irq,
  81 #ifdef CONFIG_SMP
  82         sb1250_set_affinity
  83 #else
  84         NULL
  85 #endif
  86 };
  87
  88 /* Store the CPU id (not the logical number) */
  89 int sb1250_irq_owner[SB1250_NR_IRQS];
  90
  91 spinlock_t sb1250_imr_lock = SPIN_LOCK_UNLOCKED;
  92
  93 void sb1250_mask_irq(int cpu, int irq)
  94 {
  95         unsigned long flags;
  96         u64 cur_ints;
  97
  98         spin_lock_irqsave(&sb1250_imr_lock, flags);
  99         cur_ints = ____raw_readq(IOADDR(A_IMR_MAPPER(cpu) + R_IMR_INTERRUPT_MASK));
 100         cur_ints |= (((u64) 1) << irq);
 101         ____raw_writeq(cur_ints, IOADDR(A_IMR_MAPPER(cpu) + R_IMR_INTERRUPT_MASK));
 102         spin_unlock_irqrestore(&sb1250_imr_lock, flags);
 103 }
 104
 105 void sb1250_unmask_irq(int cpu, int irq)
 106 {
 107         unsigned long flags;
 108         u64 cur_ints;
 109
 110         spin_lock_irqsave(&sb1250_imr_lock, flags);
 111         cur_ints = ____raw_readq(IOADDR(A_IMR_MAPPER(cpu) + R_IMR_INTERRUPT_MASK));
 112         cur_ints &= ~(((u64) 1) << irq);
 113         ____raw_writeq(cur_ints, IOADDR(A_IMR_MAPPER(cpu) + R_IMR_INTERRUPT_MASK));
 114         spin_unlock_irqrestore(&sb1250_imr_lock, flags);
 115 }
 116
 117 #ifdef CONFIG_SMP
 118 static void sb1250_set_affinity(unsigned int irq, unsigned long mask)
 119 {
 120         int i = 0, old_cpu, cpu, int_on;
 121         u64 cur_ints;
 122         irq_desc_t *desc = irq_desc + irq;
 123         unsigned long flags;
 124
 125         while (mask) {
 126                 if (mask & 1) {
 127                         mask >>= 1;
 128                         break;
 129                 }
 130                 mask >>= 1;
 131                 i++;
 132         }
 133
 134         if (mask) {
 135                 printk("attempted to set irq affinity for irq %d to multiple CPUs\n", irq);
 136                 return;
 137         }
 138
 139         /* Convert logical CPU to physical CPU */
 140         cpu = cpu_logical_map(i);
 141
 142         /* Protect against other affinity changers and IMR manipulation */
 143         spin_lock_irqsave(&desc->lock, flags);
 144         spin_lock(&sb1250_imr_lock);
 145
 146         /* Swizzle each CPU's IMR (but leave the IP selection alone) */
 147         old_cpu = sb1250_irq_owner[irq];
 148         cur_ints = ____raw_readq(IOADDR(A_IMR_MAPPER(old_cpu) + R_IMR_INTERRUPT_MASK));
 149         int_on = !(cur_ints & (((u64) 1) << irq));
 150         if (int_on) {
 151                 /* If it was on, mask it */
 152                 cur_ints |= (((u64) 1) << irq);
 153                 ____raw_writeq(cur_ints, IOADDR(A_IMR_MAPPER(old_cpu) + R_IMR_INTERRUPT_MASK));
 154         }
 155         sb1250_irq_owner[irq] = cpu;
 156         if (int_on) {
 157                 /* unmask for the new CPU */
 158                 cur_ints = ____raw_readq(IOADDR(A_IMR_MAPPER(cpu) + R_IMR_INTERRUPT_MASK));
 159                 cur_ints &= ~(((u64) 1) << irq);
 160                 ____raw_writeq(cur_ints, IOADDR(A_IMR_MAPPER(cpu) + R_IMR_INTERRUPT_MASK));
 161         }
 162         spin_unlock(&sb1250_imr_lock);
 163         spin_unlock_irqrestore(&desc->lock, flags);
 164 }
 165 #endif
 166
 167
 168 /* Defined in arch/mips/sibyte/sb1250/irq_handler.S */
 169 extern void sb1250_irq_handler(void);
 170
 171 /*****************************************************************************/
 172
 173 static unsigned int startup_sb1250_irq(unsigned int irq)
 174 {
 175         sb1250_unmask_irq(sb1250_irq_owner[irq], irq);
 176
 177         return 0;               /* never anything pending */
 178 }
 179
 180
 181 static void disable_sb1250_irq(unsigned int irq)
 182 {
 183         sb1250_mask_irq(sb1250_irq_owner[irq], irq);
 184 }
 185
 186 static void enable_sb1250_irq(unsigned int irq)
 187 {
 188         sb1250_unmask_irq(sb1250_irq_owner[irq], irq);
 189 }
 190
 191
 192 static void ack_sb1250_irq(unsigned int irq)
 193 {
 194 #ifdef CONFIG_SIBYTE_HAS_LDT
 195         u64 pending;
 196
 197         /*
 198          * If the interrupt was an HT interrupt, now is the time to
 199          * clear it.  NOTE: we assume the HT bridge was set up to
 200          * deliver the interrupts to all CPUs (which makes affinity
 201          * changing easier for us)
 202          */
 203         pending = __raw_readq(IOADDR(A_IMR_REGISTER(sb1250_irq_owner[irq],
 204                                                     R_IMR_LDT_INTERRUPT)));
 205         pending &= ((u64)1 << (irq));
 206         if (pending) {
 207                 int i;
 208                 for (i=0; i<NR_CPUS; i++) {
 209                         int cpu;
 210 #ifdef CONFIG_SMP
 211                         cpu = cpu_logical_map(i);
 212 #else
 213                         cpu = i;
 214 #endif
 215                         /*
 216                          * Clear for all CPUs so an affinity switch
 217                          * doesn't find an old status
 218                          */
 219                         __raw_writeq(pending,
 220                                      IOADDR(A_IMR_REGISTER(cpu, R_IMR_LDT_INTERRUPT_CLR)));
 221                 }
 222
 223                 /*
 224                  * Generate EOI.  For Pass 1 parts, EOI is a nop.  For
 225                  * Pass 2, the LDT world may be edge-triggered, but
 226                  * this EOI shouldn't hurt.  If they are
 227                  * level-sensitive, the EOI is required.
 228                  */
 229                 *(uint32_t *)(ldt_eoi_space+(irq<<16)+(7<<2)) = 0;
 230         }
 231 #endif
 232         sb1250_mask_irq(sb1250_irq_owner[irq], irq);
 233 }
 234
 235
 236 static void end_sb1250_irq(unsigned int irq)
 237 {
 238         if (!(irq_desc[irq].status & (IRQ_DISABLED | IRQ_INPROGRESS))) {
 239                 sb1250_unmask_irq(sb1250_irq_owner[irq], irq);
 240         }
 241 }
 242
 243
 244 void __init init_sb1250_irqs(void)
 245 {
 246         int i;
 247
 248         for (i = 0; i < NR_IRQS; i++) {
 249                 irq_desc[i].status = IRQ_DISABLED;
 250                 irq_desc[i].action = 0;
 251                 irq_desc[i].depth = 1;
 252                 if (i < SB1250_NR_IRQS) {
 253                         irq_desc[i].handler = &sb1250_irq_type;
 254                         sb1250_irq_owner[i] = 0;
 255                 } else {
 256                         irq_desc[i].handler = &no_irq_type;
 257                 }
 258         }
 259 }
 260
 261
 262 static irqreturn_t  sb1250_dummy_handler(int irq, void *dev_id,
 263         struct pt_regs *regs)
 264 {
 265         return IRQ_NONE;
 266 }
 267
 268 static struct irqaction sb1250_dummy_action = {
 269         .handler = sb1250_dummy_handler,
 270         .flags   = 0,
 271         .mask    = CPU_MASK_NONE,
 272         .name    = "sb1250-private",
 273         .next    = NULL,
 274         .dev_id  = 0
 275 };
 276
 277 int sb1250_steal_irq(int irq)
 278 {
 279         irq_desc_t *desc = irq_desc + irq;
 280         unsigned long flags;
 281         int retval = 0;
 282
 283         if (irq >= SB1250_NR_IRQS)
 284                 return -EINVAL;
 285
 286         spin_lock_irqsave(&desc->lock,flags);
 287         /* Don't allow sharing at all for these */
 288         if (desc->action != NULL)
 289                 retval = -EBUSY;
 290         else {
 291                 desc->action = &sb1250_dummy_action;
 292                 desc->depth = 0;
 293         }
 294         spin_unlock_irqrestore(&desc->lock,flags);
 295         return 0;
 296 }
 297
 298 /*
 299  *  arch_init_irq is called early in the boot sequence from init/main.c via
 300  *  init_IRQ.  It is responsible for setting up the interrupt mapper and
 301  *  installing the handler that will be responsible for dispatching interrupts
 302  *  to the "right" place.
 303  */
 304 /*
 305  * For now, map all interrupts to IP[2].  We could save
 306  * some cycles by parceling out system interrupts to different
 307  * IP lines, but keep it simple for bringup.  We'll also direct
 308  * all interrupts to a single CPU; we should probably route
 309  * PCI and LDT to one cpu and everything else to the other
 310  * to balance the load a bit.
 311  *
 312  * On the second cpu, everything is set to IP5, which is
 313  * ignored, EXCEPT the mailbox interrupt.  That one is
 314  * set to IP[2] so it is handled.  This is needed so we
 315  * can do cross-cpu function calls, as requred by SMP
 316  */
 317
 318 #define IMR_IP2_VAL     K_INT_MAP_I0
 319 #define IMR_IP3_VAL     K_INT_MAP_I1
 320 #define IMR_IP4_VAL     K_INT_MAP_I2
 321 #define IMR_IP5_VAL     K_INT_MAP_I3
 322 #define IMR_IP6_VAL     K_INT_MAP_I4
 323
 324 void __init arch_init_irq(void)
 325 {
 326
 327         unsigned int i;
 328         u64 tmp;
 329         unsigned int imask = STATUSF_IP4 | STATUSF_IP3 | STATUSF_IP2 |
 330                 STATUSF_IP1 | STATUSF_IP0;
 331
 332         /* Default everything to IP2 */
 333         for (i = 0; i < SB1250_NR_IRQS; i++) {  /* was I0 */
 334                 __raw_writeq(IMR_IP2_VAL,
 335                              IOADDR(A_IMR_REGISTER(0,
 336                                                    R_IMR_INTERRUPT_MAP_BASE) +
 337                                     (i << 3)));
 338                 __raw_writeq(IMR_IP2_VAL,
 339                              IOADDR(A_IMR_REGISTER(1,
 340                                                     R_IMR_INTERRUPT_MAP_BASE) +
 341                                     (i << 3)));
 342         }
 343
 344         init_sb1250_irqs();
 345
 346         /*
 347          * Map the high 16 bits of the mailbox registers to IP[3], for
 348          * inter-cpu messages
 349          */
 350         /* Was I1 */
 351         __raw_writeq(IMR_IP3_VAL, IOADDR(A_IMR_REGISTER(0, R_IMR_INTERRUPT_MAP_BASE) +
 352                                          (K_INT_MBOX_0 << 3)));
 353         __raw_writeq(IMR_IP3_VAL, IOADDR(A_IMR_REGISTER(1, R_IMR_INTERRUPT_MAP_BASE) +
 354                                          (K_INT_MBOX_0 << 3)));
 355
 356         /* Clear the mailboxes.  The firmware may leave them dirty */
 357         __raw_writeq(0xffffffffffffffff,
 358                      IOADDR(A_IMR_REGISTER(0, R_IMR_MAILBOX_CLR_CPU)));
 359         __raw_writeq(0xffffffffffffffff,
 360                      IOADDR(A_IMR_REGISTER(1, R_IMR_MAILBOX_CLR_CPU)));
 361
 362         /* Mask everything except the mailbox registers for both cpus */
 363         tmp = ~((u64) 0) ^ (((u64) 1) << K_INT_MBOX_0);
 364         __raw_writeq(tmp, IOADDR(A_IMR_REGISTER(0, R_IMR_INTERRUPT_MASK)));
 365         __raw_writeq(tmp, IOADDR(A_IMR_REGISTER(1, R_IMR_INTERRUPT_MASK)));
 366
 367         sb1250_steal_irq(K_INT_MBOX_0);
 368
 369         /*
 370          * Note that the timer interrupts are also mapped, but this is
 371          * done in sb1250_time_init().  Also, the profiling driver
 372          * does its own management of IP7.
 373          */
 374
 375 #ifdef CONFIG_KGDB
 376         imask |= STATUSF_IP6;
 377 #endif
 378         /* Enable necessary IPs, disable the rest */
 379         change_c0_status(ST0_IM, imask);
 380         set_except_vector(0, sb1250_irq_handler);
 381
 382 #ifdef CONFIG_KGDB
 383         if (kgdb_flag) {
 384                 kgdb_irq = K_INT_UART_0 + kgdb_port;
 385
 386 #ifdef CONFIG_SIBYTE_SB1250_DUART
 387                 sb1250_duart_present[kgdb_port] = 0;
 388 #endif
 389                 /* Setup uart 1 settings, mapper */
 390                 __raw_writeq(M_DUART_IMR_BRK, IOADDR(A_DUART_IMRREG(kgdb_port)));
 391
 392                 sb1250_steal_irq(kgdb_irq);
 393                 __raw_writeq(IMR_IP6_VAL,
 394                              IOADDR(A_IMR_REGISTER(0, R_IMR_INTERRUPT_MAP_BASE) +
 395                                     (kgdb_irq<<3)));
 396                 sb1250_unmask_irq(0, kgdb_irq);
 397         }
 398 #endif
 399 }
 400
 401 #ifdef CONFIG_KGDB
 402
 403 #include <linux/delay.h>
 404
 405 #define duart_out(reg, val)     csr_out32(val, IOADDR(A_DUART_CHANREG(kgdb_port,reg)))
 406 #define duart_in(reg)           csr_in32(IOADDR(A_DUART_CHANREG(kgdb_port,reg)))
 407
 408 void sb1250_kgdb_interrupt(struct pt_regs *regs)
 409 {
 410         /*
 411          * Clear break-change status (allow some time for the remote
 412          * host to stop the break, since we would see another
 413          * interrupt on the end-of-break too)
 414          */
 415         kstat_this_cpu.irqs[kgdb_irq]++;
 416         mdelay(500);
 417         duart_out(R_DUART_CMD, V_DUART_MISC_CMD_RESET_BREAK_INT |
 418                                 M_DUART_RX_EN | M_DUART_TX_EN);
 419         set_async_breakpoint(&regs->cp0_epc);
 420 }
 421
 422 #endif  /* CONFIG_KGDB */