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/smp.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/irq_regs.h>
  30 #include <asm/signal.h>
  31 #include <asm/system.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 static void end_bcm1480_irq(unsigned int irq);
  50 static void enable_bcm1480_irq(unsigned int irq);
  51 static void disable_bcm1480_irq(unsigned int irq);
  52 static void ack_bcm1480_irq(unsigned int irq);
  53 #ifdef CONFIG_SMP
  54 static int bcm1480_set_affinity(unsigned int irq, const struct cpumask *mask);
  55 #endif
  56
  57 #ifdef CONFIG_PCI
  58 extern unsigned long ht_eoi_space;
  59 #endif
  60
  61 static struct irq_chip bcm1480_irq_type = {
  62         .name = "BCM1480-IMR",
  63         .ack = ack_bcm1480_irq,
  64         .mask = disable_bcm1480_irq,
  65         .mask_ack = ack_bcm1480_irq,
  66         .unmask = enable_bcm1480_irq,
  67         .end = end_bcm1480_irq,
  68 #ifdef CONFIG_SMP
  69         .set_affinity = bcm1480_set_affinity
  70 #endif
  71 };
  72
  73 /* Store the CPU id (not the logical number) */
  74 int bcm1480_irq_owner[BCM1480_NR_IRQS];
  75
  76 DEFINE_SPINLOCK(bcm1480_imr_lock);
  77
  78 void bcm1480_mask_irq(int cpu, int irq)
  79 {
  80         unsigned long flags, hl_spacing;
  81         u64 cur_ints;
  82
  83         spin_lock_irqsave(&bcm1480_imr_lock, flags);
  84         hl_spacing = 0;
  85         if ((irq >= BCM1480_NR_IRQS_HALF) && (irq <= BCM1480_NR_IRQS)) {
  86                 hl_spacing = BCM1480_IMR_HL_SPACING;
  87                 irq -= BCM1480_NR_IRQS_HALF;
  88         }
  89         cur_ints = ____raw_readq(IOADDR(A_BCM1480_IMR_MAPPER(cpu) + R_BCM1480_IMR_INTERRUPT_MASK_H + hl_spacing));
  90         cur_ints |= (((u64) 1) << irq);
  91         ____raw_writeq(cur_ints, IOADDR(A_BCM1480_IMR_MAPPER(cpu) + R_BCM1480_IMR_INTERRUPT_MASK_H + hl_spacing));
  92         spin_unlock_irqrestore(&bcm1480_imr_lock, flags);
  93 }
  94
  95 void bcm1480_unmask_irq(int cpu, int irq)
  96 {
  97         unsigned long flags, hl_spacing;
  98         u64 cur_ints;
  99
 100         spin_lock_irqsave(&bcm1480_imr_lock, flags);
 101         hl_spacing = 0;
 102         if ((irq >= BCM1480_NR_IRQS_HALF) && (irq <= BCM1480_NR_IRQS)) {
 103                 hl_spacing = BCM1480_IMR_HL_SPACING;
 104                 irq -= BCM1480_NR_IRQS_HALF;
 105         }
 106         cur_ints = ____raw_readq(IOADDR(A_BCM1480_IMR_MAPPER(cpu) + R_BCM1480_IMR_INTERRUPT_MASK_H + hl_spacing));
 107         cur_ints &= ~(((u64) 1) << irq);
 108         ____raw_writeq(cur_ints, IOADDR(A_BCM1480_IMR_MAPPER(cpu) + R_BCM1480_IMR_INTERRUPT_MASK_H + hl_spacing));
 109         spin_unlock_irqrestore(&bcm1480_imr_lock, flags);
 110 }
 111
 112 #ifdef CONFIG_SMP
 113 static int bcm1480_set_affinity(unsigned int irq, const struct cpumask *mask)
 114 {
 115         int i = 0, old_cpu, cpu, int_on, k;
 116         u64 cur_ints;
 117         unsigned long flags;
 118         unsigned int irq_dirty;
 119
 120         i = cpumask_first(mask);
 121
 122         /* Convert logical CPU to physical CPU */
 123         cpu = cpu_logical_map(i);
 124
 125         /* Protect against other affinity changers and IMR manipulation */
 126         spin_lock_irqsave(&bcm1480_imr_lock, flags);
 127
 128         /* Swizzle each CPU's IMR (but leave the IP selection alone) */
 129         old_cpu = bcm1480_irq_owner[irq];
 130         irq_dirty = irq;
 131         if ((irq_dirty >= BCM1480_NR_IRQS_HALF) && (irq_dirty <= BCM1480_NR_IRQS)) {
 132                 irq_dirty -= BCM1480_NR_IRQS_HALF;
 133         }
 134
 135         for (k=0; k<2; k++) { /* Loop through high and low interrupt mask register */
 136                 cur_ints = ____raw_readq(IOADDR(A_BCM1480_IMR_MAPPER(old_cpu) + R_BCM1480_IMR_INTERRUPT_MASK_H + (k*BCM1480_IMR_HL_SPACING)));
 137                 int_on = !(cur_ints & (((u64) 1) << irq_dirty));
 138                 if (int_on) {
 139                         /* If it was on, mask it */
 140                         cur_ints |= (((u64) 1) << irq_dirty);
 141                         ____raw_writeq(cur_ints, IOADDR(A_BCM1480_IMR_MAPPER(old_cpu) + R_BCM1480_IMR_INTERRUPT_MASK_H + (k*BCM1480_IMR_HL_SPACING)));
 142                 }
 143                 bcm1480_irq_owner[irq] = cpu;
 144                 if (int_on) {
 145                         /* unmask for the new CPU */
 146                         cur_ints = ____raw_readq(IOADDR(A_BCM1480_IMR_MAPPER(cpu) + R_BCM1480_IMR_INTERRUPT_MASK_H + (k*BCM1480_IMR_HL_SPACING)));
 147                         cur_ints &= ~(((u64) 1) << irq_dirty);
 148                         ____raw_writeq(cur_ints, IOADDR(A_BCM1480_IMR_MAPPER(cpu) + R_BCM1480_IMR_INTERRUPT_MASK_H + (k*BCM1480_IMR_HL_SPACING)));
 149                 }
 150         }
 151         spin_unlock_irqrestore(&bcm1480_imr_lock, flags);
 152
 153         return 0;
 154 }
 155 #endif
 156
 157
 158 /*****************************************************************************/
 159
 160 static void disable_bcm1480_irq(unsigned int irq)
 161 {
 162         bcm1480_mask_irq(bcm1480_irq_owner[irq], irq);
 163 }
 164
 165 static void enable_bcm1480_irq(unsigned int irq)
 166 {
 167         bcm1480_unmask_irq(bcm1480_irq_owner[irq], irq);
 168 }
 169
 170
 171 static void ack_bcm1480_irq(unsigned int irq)
 172 {
 173         u64 pending;
 174         unsigned int irq_dirty;
 175         int k;
 176
 177         /*
 178          * If the interrupt was an HT interrupt, now is the time to
 179          * clear it.  NOTE: we assume the HT bridge was set up to
 180          * deliver the interrupts to all CPUs (which makes affinity
 181          * changing easier for us)
 182          */
 183         irq_dirty = irq;
 184         if ((irq_dirty >= BCM1480_NR_IRQS_HALF) && (irq_dirty <= BCM1480_NR_IRQS)) {
 185                 irq_dirty -= BCM1480_NR_IRQS_HALF;
 186         }
 187         for (k=0; k<2; k++) { /* Loop through high and low LDT interrupts */
 188                 pending = __raw_readq(IOADDR(A_BCM1480_IMR_REGISTER(bcm1480_irq_owner[irq],
 189                                                 R_BCM1480_IMR_LDT_INTERRUPT_H + (k*BCM1480_IMR_HL_SPACING))));
 190                 pending &= ((u64)1 << (irq_dirty));
 191                 if (pending) {
 192 #ifdef CONFIG_SMP
 193                         int i;
 194                         for (i=0; i<NR_CPUS; i++) {
 195                                 /*
 196                                  * Clear for all CPUs so an affinity switch
 197                                  * doesn't find an old status
 198                                  */
 199                                 __raw_writeq(pending, IOADDR(A_BCM1480_IMR_REGISTER(cpu_logical_map(i),
 200                                                                 R_BCM1480_IMR_LDT_INTERRUPT_CLR_H + (k*BCM1480_IMR_HL_SPACING))));
 201                         }
 202 #else
 203                         __raw_writeq(pending, IOADDR(A_BCM1480_IMR_REGISTER(0, R_BCM1480_IMR_LDT_INTERRUPT_CLR_H + (k*BCM1480_IMR_HL_SPACING))));
 204 #endif
 205
 206                         /*
 207                          * Generate EOI.  For Pass 1 parts, EOI is a nop.  For
 208                          * Pass 2, the LDT world may be edge-triggered, but
 209                          * this EOI shouldn't hurt.  If they are
 210                          * level-sensitive, the EOI is required.
 211                          */
 212 #ifdef CONFIG_PCI
 213                         if (ht_eoi_space)
 214                                 *(uint32_t *)(ht_eoi_space+(irq<<16)+(7<<2)) = 0;
 215 #endif
 216                 }
 217         }
 218         bcm1480_mask_irq(bcm1480_irq_owner[irq], irq);
 219 }
 220
 221
 222 static void end_bcm1480_irq(unsigned int irq)
 223 {
 224         if (!(irq_desc[irq].status & (IRQ_DISABLED | IRQ_INPROGRESS))) {
 225                 bcm1480_unmask_irq(bcm1480_irq_owner[irq], irq);
 226         }
 227 }
 228
 229
 230 void __init init_bcm1480_irqs(void)
 231 {
 232         int i;
 233
 234         for (i = 0; i < BCM1480_NR_IRQS; i++) {
 235                 set_irq_chip_and_handler(i, &bcm1480_irq_type, handle_level_irq);
 236                 bcm1480_irq_owner[i] = 0;
 237         }
 238 }
 239
 240 /*
 241  *  init_IRQ is called early in the boot sequence from init/main.c.  It
 242  *  is responsible for setting up the interrupt mapper and installing the
 243  *  handler that will be responsible for dispatching interrupts to the
 244  *  "right" place.
 245  */
 246 /*
 247  * For now, map all interrupts to IP[2].  We could save
 248  * some cycles by parceling out system interrupts to different
 249  * IP lines, but keep it simple for bringup.  We'll also direct
 250  * all interrupts to a single CPU; we should probably route
 251  * PCI and LDT to one cpu and everything else to the other
 252  * to balance the load a bit.
 253  *
 254  * On the second cpu, everything is set to IP5, which is
 255  * ignored, EXCEPT the mailbox interrupt.  That one is
 256  * set to IP[2] so it is handled.  This is needed so we
 257  * can do cross-cpu function calls, as requred by SMP
 258  */
 259
 260 #define IMR_IP2_VAL     K_BCM1480_INT_MAP_I0
 261 #define IMR_IP3_VAL     K_BCM1480_INT_MAP_I1
 262 #define IMR_IP4_VAL     K_BCM1480_INT_MAP_I2
 263 #define IMR_IP5_VAL     K_BCM1480_INT_MAP_I3
 264 #define IMR_IP6_VAL     K_BCM1480_INT_MAP_I4
 265
 266 void __init arch_init_irq(void)
 267 {
 268         unsigned int i, cpu;
 269         u64 tmp;
 270         unsigned int imask = STATUSF_IP4 | STATUSF_IP3 | STATUSF_IP2 |
 271                 STATUSF_IP1 | STATUSF_IP0;
 272
 273         /* Default everything to IP2 */
 274         /* Start with _high registers which has no bit 0 interrupt source */
 275         for (i = 1; i < BCM1480_NR_IRQS_HALF; i++) {    /* was I0 */
 276                 for (cpu = 0; cpu < 4; cpu++) {
 277                         __raw_writeq(IMR_IP2_VAL,
 278                                      IOADDR(A_BCM1480_IMR_REGISTER(cpu,
 279                                                                    R_BCM1480_IMR_INTERRUPT_MAP_BASE_H) + (i << 3)));
 280                 }
 281         }
 282
 283         /* Now do _low registers */
 284         for (i = 0; i < BCM1480_NR_IRQS_HALF; i++) {
 285                 for (cpu = 0; cpu < 4; cpu++) {
 286                         __raw_writeq(IMR_IP2_VAL,
 287                                      IOADDR(A_BCM1480_IMR_REGISTER(cpu,
 288                                                                    R_BCM1480_IMR_INTERRUPT_MAP_BASE_L) + (i << 3)));
 289                 }
 290         }
 291
 292         init_bcm1480_irqs();
 293
 294         /*
 295          * Map the high 16 bits of mailbox_0 registers to IP[3], for
 296          * inter-cpu messages
 297          */
 298         /* Was I1 */
 299         for (cpu = 0; cpu < 4; cpu++) {
 300                 __raw_writeq(IMR_IP3_VAL, IOADDR(A_BCM1480_IMR_REGISTER(cpu, R_BCM1480_IMR_INTERRUPT_MAP_BASE_H) +
 301                                                  (K_BCM1480_INT_MBOX_0_0 << 3)));
 302         }
 303
 304
 305         /* Clear the mailboxes.  The firmware may leave them dirty */
 306         for (cpu = 0; cpu < 4; cpu++) {
 307                 __raw_writeq(0xffffffffffffffffULL,
 308                              IOADDR(A_BCM1480_IMR_REGISTER(cpu, R_BCM1480_IMR_MAILBOX_0_CLR_CPU)));
 309                 __raw_writeq(0xffffffffffffffffULL,
 310                              IOADDR(A_BCM1480_IMR_REGISTER(cpu, R_BCM1480_IMR_MAILBOX_1_CLR_CPU)));
 311         }
 312
 313
 314         /* Mask everything except the high 16 bit of mailbox_0 registers for all cpus */
 315         tmp = ~((u64) 0) ^ ( (((u64) 1) << K_BCM1480_INT_MBOX_0_0));
 316         for (cpu = 0; cpu < 4; cpu++) {
 317                 __raw_writeq(tmp, IOADDR(A_BCM1480_IMR_REGISTER(cpu, R_BCM1480_IMR_INTERRUPT_MASK_H)));
 318         }
 319         tmp = ~((u64) 0);
 320         for (cpu = 0; cpu < 4; cpu++) {
 321                 __raw_writeq(tmp, IOADDR(A_BCM1480_IMR_REGISTER(cpu, R_BCM1480_IMR_INTERRUPT_MASK_L)));
 322         }
 323
 324         /*
 325          * Note that the timer interrupts are also mapped, but this is
 326          * done in bcm1480_time_init().  Also, the profiling driver
 327          * does its own management of IP7.
 328          */
 329
 330         /* Enable necessary IPs, disable the rest */
 331         change_c0_status(ST0_IM, imask);
 332 }
 333
 334 extern void bcm1480_mailbox_interrupt(void);
 335
 336 static inline void dispatch_ip2(void)
 337 {
 338         unsigned long long mask_h, mask_l;
 339         unsigned int cpu = smp_processor_id();
 340         unsigned long base;
 341
 342         /*
 343          * Default...we've hit an IP[2] interrupt, which means we've got to
 344          * check the 1480 interrupt registers to figure out what to do.  Need
 345          * to detect which CPU we're on, now that smp_affinity is supported.
 346          */
 347         base = A_BCM1480_IMR_MAPPER(cpu);
 348         mask_h = __raw_readq(
 349                 IOADDR(base + R_BCM1480_IMR_INTERRUPT_STATUS_BASE_H));
 350         mask_l = __raw_readq(
 351                 IOADDR(base + R_BCM1480_IMR_INTERRUPT_STATUS_BASE_L));
 352
 353         if (mask_h) {
 354                 if (mask_h ^ 1)
 355                         do_IRQ(fls64(mask_h) - 1);
 356                 else if (mask_l)
 357                         do_IRQ(63 + fls64(mask_l));
 358         }
 359 }
 360
 361 asmlinkage void plat_irq_dispatch(void)
 362 {
 363         unsigned int cpu = smp_processor_id();
 364         unsigned int pending;
 365
 366 #ifdef CONFIG_SIBYTE_BCM1480_PROF
 367         /* Set compare to count to silence count/compare timer interrupts */
 368         write_c0_compare(read_c0_count());
 369 #endif
 370
 371         pending = read_c0_cause() & read_c0_status();
 372
 373 #ifdef CONFIG_SIBYTE_BCM1480_PROF
 374         if (pending & CAUSEF_IP7)       /* Cpu performance counter interrupt */
 375                 sbprof_cpu_intr();
 376         else
 377 #endif
 378
 379         if (pending & CAUSEF_IP4)
 380                 do_IRQ(K_BCM1480_INT_TIMER_0 + cpu);
 381 #ifdef CONFIG_SMP
 382         else if (pending & CAUSEF_IP3)
 383                 bcm1480_mailbox_interrupt();
 384 #endif
 385
 386         else if (pending & CAUSEF_IP2)
 387                 dispatch_ip2();
 388 }