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/kernel_stat.h>
  26
  27 #include <asm/errno.h>
  28 #include <asm/irq_regs.h>
  29 #include <asm/signal.h>
  30 #include <asm/io.h>
  31
  32 #include <asm/sibyte/bcm1480_regs.h>
  33 #include <asm/sibyte/bcm1480_int.h>
  34 #include <asm/sibyte/bcm1480_scd.h>
  35
  36 #include <asm/sibyte/sb1250_uart.h>
  37 #include <asm/sibyte/sb1250.h>
  38
  39 /*
  40  * These are the routines that handle all the low level interrupt stuff.
  41  * Actions handled here are: initialization of the interrupt map, requesting of
  42  * interrupt lines by handlers, dispatching if interrupts to handlers, probing
  43  * for interrupt lines
  44  */
  45
  46 #ifdef CONFIG_PCI
  47 extern unsigned long ht_eoi_space;
  48 #endif
  49
  50 /* Store the CPU id (not the logical number) */
  51 int bcm1480_irq_owner[BCM1480_NR_IRQS];
  52
  53 static DEFINE_RAW_SPINLOCK(bcm1480_imr_lock);
  54
  55 void bcm1480_mask_irq(int cpu, int irq)
  56 {
  57         unsigned long flags, hl_spacing;
  58         u64 cur_ints;
  59
  60         raw_spin_lock_irqsave(&bcm1480_imr_lock, flags);
  61         hl_spacing = 0;
  62         if ((irq >= BCM1480_NR_IRQS_HALF) && (irq <= BCM1480_NR_IRQS)) {
  63                 hl_spacing = BCM1480_IMR_HL_SPACING;
  64                 irq -= BCM1480_NR_IRQS_HALF;
  65         }
  66         cur_ints = ____raw_readq(IOADDR(A_BCM1480_IMR_MAPPER(cpu) + R_BCM1480_IMR_INTERRUPT_MASK_H + hl_spacing));
  67         cur_ints |= (((u64) 1) << irq);
  68         ____raw_writeq(cur_ints, IOADDR(A_BCM1480_IMR_MAPPER(cpu) + R_BCM1480_IMR_INTERRUPT_MASK_H + hl_spacing));
  69         raw_spin_unlock_irqrestore(&bcm1480_imr_lock, flags);
  70 }
  71
  72 void bcm1480_unmask_irq(int cpu, int irq)
  73 {
  74         unsigned long flags, hl_spacing;
  75         u64 cur_ints;
  76
  77         raw_spin_lock_irqsave(&bcm1480_imr_lock, flags);
  78         hl_spacing = 0;
  79         if ((irq >= BCM1480_NR_IRQS_HALF) && (irq <= BCM1480_NR_IRQS)) {
  80                 hl_spacing = BCM1480_IMR_HL_SPACING;
  81                 irq -= BCM1480_NR_IRQS_HALF;
  82         }
  83         cur_ints = ____raw_readq(IOADDR(A_BCM1480_IMR_MAPPER(cpu) + R_BCM1480_IMR_INTERRUPT_MASK_H + hl_spacing));
  84         cur_ints &= ~(((u64) 1) << irq);
  85         ____raw_writeq(cur_ints, IOADDR(A_BCM1480_IMR_MAPPER(cpu) + R_BCM1480_IMR_INTERRUPT_MASK_H + hl_spacing));
  86         raw_spin_unlock_irqrestore(&bcm1480_imr_lock, flags);
  87 }
  88
  89 #ifdef CONFIG_SMP
  90 static int bcm1480_set_affinity(struct irq_data *d, const struct cpumask *mask,
  91                                 bool force)
  92 {
  93         unsigned int irq_dirty, irq = d->irq;
  94         int i = 0, old_cpu, cpu, int_on, k;
  95         u64 cur_ints;
  96         unsigned long flags;
  97
  98         i = cpumask_first_and(mask, cpu_online_mask);
  99
 100         /* Convert logical CPU to physical CPU */
 101         cpu = cpu_logical_map(i);
 102
 103         /* Protect against other affinity changers and IMR manipulation */
 104         raw_spin_lock_irqsave(&bcm1480_imr_lock, flags);
 105
 106         /* Swizzle each CPU's IMR (but leave the IP selection alone) */
 107         old_cpu = bcm1480_irq_owner[irq];
 108         irq_dirty = irq;
 109         if ((irq_dirty >= BCM1480_NR_IRQS_HALF) && (irq_dirty <= BCM1480_NR_IRQS)) {
 110                 irq_dirty -= BCM1480_NR_IRQS_HALF;
 111         }
 112
 113         for (k=0; k<2; k++) { /* Loop through high and low interrupt mask register */
 114                 cur_ints = ____raw_readq(IOADDR(A_BCM1480_IMR_MAPPER(old_cpu) + R_BCM1480_IMR_INTERRUPT_MASK_H + (k*BCM1480_IMR_HL_SPACING)));
 115                 int_on = !(cur_ints & (((u64) 1) << irq_dirty));
 116                 if (int_on) {
 117                         /* If it was on, mask it */
 118                         cur_ints |= (((u64) 1) << irq_dirty);
 119                         ____raw_writeq(cur_ints, IOADDR(A_BCM1480_IMR_MAPPER(old_cpu) + R_BCM1480_IMR_INTERRUPT_MASK_H + (k*BCM1480_IMR_HL_SPACING)));
 120                 }
 121                 bcm1480_irq_owner[irq] = cpu;
 122                 if (int_on) {
 123                         /* unmask for the new CPU */
 124                         cur_ints = ____raw_readq(IOADDR(A_BCM1480_IMR_MAPPER(cpu) + R_BCM1480_IMR_INTERRUPT_MASK_H + (k*BCM1480_IMR_HL_SPACING)));
 125                         cur_ints &= ~(((u64) 1) << irq_dirty);
 126                         ____raw_writeq(cur_ints, IOADDR(A_BCM1480_IMR_MAPPER(cpu) + R_BCM1480_IMR_INTERRUPT_MASK_H + (k*BCM1480_IMR_HL_SPACING)));
 127                 }
 128         }
 129         raw_spin_unlock_irqrestore(&bcm1480_imr_lock, flags);
 130
 131         return 0;
 132 }
 133 #endif
 134
 135
 136 /*****************************************************************************/
 137
 138 static void disable_bcm1480_irq(struct irq_data *d)
 139 {
 140         unsigned int irq = d->irq;
 141
 142         bcm1480_mask_irq(bcm1480_irq_owner[irq], irq);
 143 }
 144
 145 static void enable_bcm1480_irq(struct irq_data *d)
 146 {
 147         unsigned int irq = d->irq;
 148
 149         bcm1480_unmask_irq(bcm1480_irq_owner[irq], irq);
 150 }
 151
 152
 153 static void ack_bcm1480_irq(struct irq_data *d)
 154 {
 155         unsigned int irq_dirty, irq = d->irq;
 156         u64 pending;
 157         int k;
 158
 159         /*
 160          * If the interrupt was an HT interrupt, now is the time to
 161          * clear it.  NOTE: we assume the HT bridge was set up to
 162          * deliver the interrupts to all CPUs (which makes affinity
 163          * changing easier for us)
 164          */
 165         irq_dirty = irq;
 166         if ((irq_dirty >= BCM1480_NR_IRQS_HALF) && (irq_dirty <= BCM1480_NR_IRQS)) {
 167                 irq_dirty -= BCM1480_NR_IRQS_HALF;
 168         }
 169         for (k=0; k<2; k++) { /* Loop through high and low LDT interrupts */
 170                 pending = __raw_readq(IOADDR(A_BCM1480_IMR_REGISTER(bcm1480_irq_owner[irq],
 171                                                 R_BCM1480_IMR_LDT_INTERRUPT_H + (k*BCM1480_IMR_HL_SPACING))));
 172                 pending &= ((u64)1 << (irq_dirty));
 173                 if (pending) {
 174 #ifdef CONFIG_SMP
 175                         int i;
 176                         for (i=0; i<NR_CPUS; i++) {
 177                                 /*
 178                                  * Clear for all CPUs so an affinity switch
 179                                  * doesn't find an old status
 180                                  */
 181                                 __raw_writeq(pending, IOADDR(A_BCM1480_IMR_REGISTER(cpu_logical_map(i),
 182                                                                 R_BCM1480_IMR_LDT_INTERRUPT_CLR_H + (k*BCM1480_IMR_HL_SPACING))));
 183                         }
 184 #else
 185                         __raw_writeq(pending, IOADDR(A_BCM1480_IMR_REGISTER(0, R_BCM1480_IMR_LDT_INTERRUPT_CLR_H + (k*BCM1480_IMR_HL_SPACING))));
 186 #endif
 187
 188                         /*
 189                          * Generate EOI.  For Pass 1 parts, EOI is a nop.  For
 190                          * Pass 2, the LDT world may be edge-triggered, but
 191                          * this EOI shouldn't hurt.  If they are
 192                          * level-sensitive, the EOI is required.
 193                          */
 194 #ifdef CONFIG_PCI
 195                         if (ht_eoi_space)
 196                                 *(uint32_t *)(ht_eoi_space+(irq<<16)+(7<<2)) = 0;
 197 #endif
 198                 }
 199         }
 200         bcm1480_mask_irq(bcm1480_irq_owner[irq], irq);
 201 }
 202
 203 static struct irq_chip bcm1480_irq_type = {
 204         .name = "BCM1480-IMR",
 205         .irq_mask_ack = ack_bcm1480_irq,
 206         .irq_mask = disable_bcm1480_irq,
 207         .irq_unmask = enable_bcm1480_irq,
 208 #ifdef CONFIG_SMP
 209         .irq_set_affinity = bcm1480_set_affinity
 210 #endif
 211 };
 212
 213 void __init init_bcm1480_irqs(void)
 214 {
 215         int i;
 216
 217         for (i = 0; i < BCM1480_NR_IRQS; i++) {
 218                 irq_set_chip_and_handler(i, &bcm1480_irq_type,
 219                                          handle_level_irq);
 220                 bcm1480_irq_owner[i] = 0;
 221         }
 222 }
 223
 224 /*
 225  *  init_IRQ is called early in the boot sequence from init/main.c.  It
 226  *  is responsible for setting up the interrupt mapper and installing the
 227  *  handler that will be responsible for dispatching interrupts to the
 228  *  "right" place.
 229  */
 230 /*
 231  * For now, map all interrupts to IP[2].  We could save
 232  * some cycles by parceling out system interrupts to different
 233  * IP lines, but keep it simple for bringup.  We'll also direct
 234  * all interrupts to a single CPU; we should probably route
 235  * PCI and LDT to one cpu and everything else to the other
 236  * to balance the load a bit.
 237  *
 238  * On the second cpu, everything is set to IP5, which is
 239  * ignored, EXCEPT the mailbox interrupt.  That one is
 240  * set to IP[2] so it is handled.  This is needed so we
 241  * can do cross-cpu function calls, as required by SMP
 242  */
 243
 244 #define IMR_IP2_VAL     K_BCM1480_INT_MAP_I0
 245 #define IMR_IP3_VAL     K_BCM1480_INT_MAP_I1
 246 #define IMR_IP4_VAL     K_BCM1480_INT_MAP_I2
 247 #define IMR_IP5_VAL     K_BCM1480_INT_MAP_I3
 248 #define IMR_IP6_VAL     K_BCM1480_INT_MAP_I4
 249
 250 void __init arch_init_irq(void)
 251 {
 252         unsigned int i, cpu;
 253         u64 tmp;
 254         unsigned int imask = STATUSF_IP4 | STATUSF_IP3 | STATUSF_IP2 |
 255                 STATUSF_IP1 | STATUSF_IP0;
 256
 257         /* Default everything to IP2 */
 258         /* Start with _high registers which has no bit 0 interrupt source */
 259         for (i = 1; i < BCM1480_NR_IRQS_HALF; i++) {    /* was I0 */
 260                 for (cpu = 0; cpu < 4; cpu++) {
 261                         __raw_writeq(IMR_IP2_VAL,
 262                                      IOADDR(A_BCM1480_IMR_REGISTER(cpu,
 263                                                                    R_BCM1480_IMR_INTERRUPT_MAP_BASE_H) + (i << 3)));
 264                 }
 265         }
 266
 267         /* Now do _low registers */
 268         for (i = 0; i < BCM1480_NR_IRQS_HALF; i++) {
 269                 for (cpu = 0; cpu < 4; cpu++) {
 270                         __raw_writeq(IMR_IP2_VAL,
 271                                      IOADDR(A_BCM1480_IMR_REGISTER(cpu,
 272                                                                    R_BCM1480_IMR_INTERRUPT_MAP_BASE_L) + (i << 3)));
 273                 }
 274         }
 275
 276         init_bcm1480_irqs();
 277
 278         /*
 279          * Map the high 16 bits of mailbox_0 registers to IP[3], for
 280          * inter-cpu messages
 281          */
 282         /* Was I1 */
 283         for (cpu = 0; cpu < 4; cpu++) {
 284                 __raw_writeq(IMR_IP3_VAL, IOADDR(A_BCM1480_IMR_REGISTER(cpu, R_BCM1480_IMR_INTERRUPT_MAP_BASE_H) +
 285                                                  (K_BCM1480_INT_MBOX_0_0 << 3)));
 286         }
 287
 288
 289         /* Clear the mailboxes.  The firmware may leave them dirty */
 290         for (cpu = 0; cpu < 4; cpu++) {
 291                 __raw_writeq(0xffffffffffffffffULL,
 292                              IOADDR(A_BCM1480_IMR_REGISTER(cpu, R_BCM1480_IMR_MAILBOX_0_CLR_CPU)));
 293                 __raw_writeq(0xffffffffffffffffULL,
 294                              IOADDR(A_BCM1480_IMR_REGISTER(cpu, R_BCM1480_IMR_MAILBOX_1_CLR_CPU)));
 295         }
 296
 297
 298         /* Mask everything except the high 16 bit of mailbox_0 registers for all cpus */
 299         tmp = ~((u64) 0) ^ ( (((u64) 1) << K_BCM1480_INT_MBOX_0_0));
 300         for (cpu = 0; cpu < 4; cpu++) {
 301                 __raw_writeq(tmp, IOADDR(A_BCM1480_IMR_REGISTER(cpu, R_BCM1480_IMR_INTERRUPT_MASK_H)));
 302         }
 303         tmp = ~((u64) 0);
 304         for (cpu = 0; cpu < 4; cpu++) {
 305                 __raw_writeq(tmp, IOADDR(A_BCM1480_IMR_REGISTER(cpu, R_BCM1480_IMR_INTERRUPT_MASK_L)));
 306         }
 307
 308         /*
 309          * Note that the timer interrupts are also mapped, but this is
 310          * done in bcm1480_time_init().  Also, the profiling driver
 311          * does its own management of IP7.
 312          */
 313
 314         /* Enable necessary IPs, disable the rest */
 315         change_c0_status(ST0_IM, imask);
 316 }
 317
 318 extern void bcm1480_mailbox_interrupt(void);
 319
 320 static inline void dispatch_ip2(void)
 321 {
 322         unsigned long long mask_h, mask_l;
 323         unsigned int cpu = smp_processor_id();
 324         unsigned long base;
 325
 326         /*
 327          * Default...we've hit an IP[2] interrupt, which means we've got to
 328          * check the 1480 interrupt registers to figure out what to do.  Need
 329          * to detect which CPU we're on, now that smp_affinity is supported.
 330          */
 331         base = A_BCM1480_IMR_MAPPER(cpu);
 332         mask_h = __raw_readq(
 333                 IOADDR(base + R_BCM1480_IMR_INTERRUPT_STATUS_BASE_H));
 334         mask_l = __raw_readq(
 335                 IOADDR(base + R_BCM1480_IMR_INTERRUPT_STATUS_BASE_L));
 336
 337         if (mask_h) {
 338                 if (mask_h ^ 1)
 339                         do_IRQ(fls64(mask_h) - 1);
 340                 else if (mask_l)
 341                         do_IRQ(63 + fls64(mask_l));
 342         }
 343 }
 344
 345 asmlinkage void plat_irq_dispatch(void)
 346 {
 347         unsigned int cpu = smp_processor_id();
 348         unsigned int pending;
 349
 350         pending = read_c0_cause() & read_c0_status();
 351
 352         if (pending & CAUSEF_IP4)
 353                 do_IRQ(K_BCM1480_INT_TIMER_0 + cpu);
 354 #ifdef CONFIG_SMP
 355         else if (pending & CAUSEF_IP3)
 356                 bcm1480_mailbox_interrupt();
 357 #endif
 358
 359         else if (pending & CAUSEF_IP2)
 360                 dispatch_ip2();
 361 }