arch/mips/sibyte/bcm1480/irq.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Copyright (C) 2000,2001,2002,2003,2004 Broadcom Corporation
   4  */
   5 #include <linux/kernel.h>
   6 #include <linux/init.h>
   7 #include <linux/linkage.h>
   8 #include <linux/interrupt.h>
   9 #include <linux/smp.h>
  10 #include <linux/spinlock.h>
  11 #include <linux/mm.h>
  12 #include <linux/kernel_stat.h>
  13
  14 #include <asm/errno.h>
  15 #include <asm/irq_regs.h>
  16 #include <asm/signal.h>
  17 #include <asm/io.h>
  18
  19 #include <asm/sibyte/bcm1480_regs.h>
  20 #include <asm/sibyte/bcm1480_int.h>
  21 #include <asm/sibyte/bcm1480_scd.h>
  22
  23 #include <asm/sibyte/sb1250_uart.h>
  24 #include <asm/sibyte/sb1250.h>
  25
  26 /*
  27  * These are the routines that handle all the low level interrupt stuff.
  28  * Actions handled here are: initialization of the interrupt map, requesting of
  29  * interrupt lines by handlers, dispatching if interrupts to handlers, probing
  30  * for interrupt lines
  31  */
  32
  33 #ifdef CONFIG_PCI
  34 extern unsigned long ht_eoi_space;
  35 #endif
  36
  37 /* Store the CPU id (not the logical number) */
  38 int bcm1480_irq_owner[BCM1480_NR_IRQS];
  39
  40 static DEFINE_RAW_SPINLOCK(bcm1480_imr_lock);
  41
  42 void bcm1480_mask_irq(int cpu, int irq)
  43 {
  44         unsigned long flags, hl_spacing;
  45         u64 cur_ints;
  46
  47         raw_spin_lock_irqsave(&bcm1480_imr_lock, flags);
  48         hl_spacing = 0;
  49         if ((irq >= BCM1480_NR_IRQS_HALF) && (irq <= BCM1480_NR_IRQS)) {
  50                 hl_spacing = BCM1480_IMR_HL_SPACING;
  51                 irq -= BCM1480_NR_IRQS_HALF;
  52         }
  53         cur_ints = ____raw_readq(IOADDR(A_BCM1480_IMR_MAPPER(cpu) + R_BCM1480_IMR_INTERRUPT_MASK_H + hl_spacing));
  54         cur_ints |= (((u64) 1) << irq);
  55         ____raw_writeq(cur_ints, IOADDR(A_BCM1480_IMR_MAPPER(cpu) + R_BCM1480_IMR_INTERRUPT_MASK_H + hl_spacing));
  56         raw_spin_unlock_irqrestore(&bcm1480_imr_lock, flags);
  57 }
  58
  59 void bcm1480_unmask_irq(int cpu, int irq)
  60 {
  61         unsigned long flags, hl_spacing;
  62         u64 cur_ints;
  63
  64         raw_spin_lock_irqsave(&bcm1480_imr_lock, flags);
  65         hl_spacing = 0;
  66         if ((irq >= BCM1480_NR_IRQS_HALF) && (irq <= BCM1480_NR_IRQS)) {
  67                 hl_spacing = BCM1480_IMR_HL_SPACING;
  68                 irq -= BCM1480_NR_IRQS_HALF;
  69         }
  70         cur_ints = ____raw_readq(IOADDR(A_BCM1480_IMR_MAPPER(cpu) + R_BCM1480_IMR_INTERRUPT_MASK_H + hl_spacing));
  71         cur_ints &= ~(((u64) 1) << irq);
  72         ____raw_writeq(cur_ints, IOADDR(A_BCM1480_IMR_MAPPER(cpu) + R_BCM1480_IMR_INTERRUPT_MASK_H + hl_spacing));
  73         raw_spin_unlock_irqrestore(&bcm1480_imr_lock, flags);
  74 }
  75
  76 #ifdef CONFIG_SMP
  77 static int bcm1480_set_affinity(struct irq_data *d, const struct cpumask *mask,
  78                                 bool force)
  79 {
  80         unsigned int irq_dirty, irq = d->irq;
  81         int i = 0, old_cpu, cpu, int_on, k;
  82         u64 cur_ints;
  83         unsigned long flags;
  84
  85         i = cpumask_first_and(mask, cpu_online_mask);
  86
  87         /* Convert logical CPU to physical CPU */
  88         cpu = cpu_logical_map(i);
  89
  90         /* Protect against other affinity changers and IMR manipulation */
  91         raw_spin_lock_irqsave(&bcm1480_imr_lock, flags);
  92
  93         /* Swizzle each CPU's IMR (but leave the IP selection alone) */
  94         old_cpu = bcm1480_irq_owner[irq];
  95         irq_dirty = irq;
  96         if ((irq_dirty >= BCM1480_NR_IRQS_HALF) && (irq_dirty <= BCM1480_NR_IRQS)) {
  97                 irq_dirty -= BCM1480_NR_IRQS_HALF;
  98         }
  99
 100         for (k=0; k<2; k++) { /* Loop through high and low interrupt mask register */
 101                 cur_ints = ____raw_readq(IOADDR(A_BCM1480_IMR_MAPPER(old_cpu) + R_BCM1480_IMR_INTERRUPT_MASK_H + (k*BCM1480_IMR_HL_SPACING)));
 102                 int_on = !(cur_ints & (((u64) 1) << irq_dirty));
 103                 if (int_on) {
 104                         /* If it was on, mask it */
 105                         cur_ints |= (((u64) 1) << irq_dirty);
 106                         ____raw_writeq(cur_ints, IOADDR(A_BCM1480_IMR_MAPPER(old_cpu) + R_BCM1480_IMR_INTERRUPT_MASK_H + (k*BCM1480_IMR_HL_SPACING)));
 107                 }
 108                 bcm1480_irq_owner[irq] = cpu;
 109                 if (int_on) {
 110                         /* unmask for the new CPU */
 111                         cur_ints = ____raw_readq(IOADDR(A_BCM1480_IMR_MAPPER(cpu) + R_BCM1480_IMR_INTERRUPT_MASK_H + (k*BCM1480_IMR_HL_SPACING)));
 112                         cur_ints &= ~(((u64) 1) << irq_dirty);
 113                         ____raw_writeq(cur_ints, IOADDR(A_BCM1480_IMR_MAPPER(cpu) + R_BCM1480_IMR_INTERRUPT_MASK_H + (k*BCM1480_IMR_HL_SPACING)));
 114                 }
 115         }
 116         raw_spin_unlock_irqrestore(&bcm1480_imr_lock, flags);
 117
 118         return 0;
 119 }
 120 #endif
 121
 122
 123 /*****************************************************************************/
 124
 125 static void disable_bcm1480_irq(struct irq_data *d)
 126 {
 127         unsigned int irq = d->irq;
 128
 129         bcm1480_mask_irq(bcm1480_irq_owner[irq], irq);
 130 }
 131
 132 static void enable_bcm1480_irq(struct irq_data *d)
 133 {
 134         unsigned int irq = d->irq;
 135
 136         bcm1480_unmask_irq(bcm1480_irq_owner[irq], irq);
 137 }
 138
 139
 140 static void ack_bcm1480_irq(struct irq_data *d)
 141 {
 142         unsigned int irq_dirty, irq = d->irq;
 143         u64 pending;
 144         int k;
 145
 146         /*
 147          * If the interrupt was an HT interrupt, now is the time to
 148          * clear it.  NOTE: we assume the HT bridge was set up to
 149          * deliver the interrupts to all CPUs (which makes affinity
 150          * changing easier for us)
 151          */
 152         irq_dirty = irq;
 153         if ((irq_dirty >= BCM1480_NR_IRQS_HALF) && (irq_dirty <= BCM1480_NR_IRQS)) {
 154                 irq_dirty -= BCM1480_NR_IRQS_HALF;
 155         }
 156         for (k=0; k<2; k++) { /* Loop through high and low LDT interrupts */
 157                 pending = __raw_readq(IOADDR(A_BCM1480_IMR_REGISTER(bcm1480_irq_owner[irq],
 158                                                 R_BCM1480_IMR_LDT_INTERRUPT_H + (k*BCM1480_IMR_HL_SPACING))));
 159                 pending &= ((u64)1 << (irq_dirty));
 160                 if (pending) {
 161 #ifdef CONFIG_SMP
 162                         int i;
 163                         for (i=0; i<NR_CPUS; i++) {
 164                                 /*
 165                                  * Clear for all CPUs so an affinity switch
 166                                  * doesn't find an old status
 167                                  */
 168                                 __raw_writeq(pending, IOADDR(A_BCM1480_IMR_REGISTER(cpu_logical_map(i),
 169                                                                 R_BCM1480_IMR_LDT_INTERRUPT_CLR_H + (k*BCM1480_IMR_HL_SPACING))));
 170                         }
 171 #else
 172                         __raw_writeq(pending, IOADDR(A_BCM1480_IMR_REGISTER(0, R_BCM1480_IMR_LDT_INTERRUPT_CLR_H + (k*BCM1480_IMR_HL_SPACING))));
 173 #endif
 174
 175                         /*
 176                          * Generate EOI.  For Pass 1 parts, EOI is a nop.  For
 177                          * Pass 2, the LDT world may be edge-triggered, but
 178                          * this EOI shouldn't hurt.  If they are
 179                          * level-sensitive, the EOI is required.
 180                          */
 181 #ifdef CONFIG_PCI
 182                         if (ht_eoi_space)
 183                                 *(uint32_t *)(ht_eoi_space+(irq<<16)+(7<<2)) = 0;
 184 #endif
 185                 }
 186         }
 187         bcm1480_mask_irq(bcm1480_irq_owner[irq], irq);
 188 }
 189
 190 static struct irq_chip bcm1480_irq_type = {
 191         .name = "BCM1480-IMR",
 192         .irq_mask_ack = ack_bcm1480_irq,
 193         .irq_mask = disable_bcm1480_irq,
 194         .irq_unmask = enable_bcm1480_irq,
 195 #ifdef CONFIG_SMP
 196         .irq_set_affinity = bcm1480_set_affinity
 197 #endif
 198 };
 199
 200 void __init init_bcm1480_irqs(void)
 201 {
 202         int i;
 203
 204         for (i = 0; i < BCM1480_NR_IRQS; i++) {
 205                 irq_set_chip_and_handler(i, &bcm1480_irq_type,
 206                                          handle_level_irq);
 207                 bcm1480_irq_owner[i] = 0;
 208         }
 209 }
 210
 211 /*
 212  *  init_IRQ is called early in the boot sequence from init/main.c.  It
 213  *  is responsible for setting up the interrupt mapper and installing the
 214  *  handler that will be responsible for dispatching interrupts to the
 215  *  "right" place.
 216  */
 217 /*
 218  * For now, map all interrupts to IP[2].  We could save
 219  * some cycles by parceling out system interrupts to different
 220  * IP lines, but keep it simple for bringup.  We'll also direct
 221  * all interrupts to a single CPU; we should probably route
 222  * PCI and LDT to one cpu and everything else to the other
 223  * to balance the load a bit.
 224  *
 225  * On the second cpu, everything is set to IP5, which is
 226  * ignored, EXCEPT the mailbox interrupt.  That one is
 227  * set to IP[2] so it is handled.  This is needed so we
 228  * can do cross-cpu function calls, as required by SMP
 229  */
 230
 231 #define IMR_IP2_VAL     K_BCM1480_INT_MAP_I0
 232 #define IMR_IP3_VAL     K_BCM1480_INT_MAP_I1
 233 #define IMR_IP4_VAL     K_BCM1480_INT_MAP_I2
 234 #define IMR_IP5_VAL     K_BCM1480_INT_MAP_I3
 235 #define IMR_IP6_VAL     K_BCM1480_INT_MAP_I4
 236
 237 void __init arch_init_irq(void)
 238 {
 239         unsigned int i, cpu;
 240         u64 tmp;
 241         unsigned int imask = STATUSF_IP4 | STATUSF_IP3 | STATUSF_IP2 |
 242                 STATUSF_IP1 | STATUSF_IP0;
 243
 244         /* Default everything to IP2 */
 245         /* Start with _high registers which has no bit 0 interrupt source */
 246         for (i = 1; i < BCM1480_NR_IRQS_HALF; i++) {    /* was I0 */
 247                 for (cpu = 0; cpu < 4; cpu++) {
 248                         __raw_writeq(IMR_IP2_VAL,
 249                                      IOADDR(A_BCM1480_IMR_REGISTER(cpu,
 250                                                                    R_BCM1480_IMR_INTERRUPT_MAP_BASE_H) + (i << 3)));
 251                 }
 252         }
 253
 254         /* Now do _low registers */
 255         for (i = 0; i < BCM1480_NR_IRQS_HALF; i++) {
 256                 for (cpu = 0; cpu < 4; cpu++) {
 257                         __raw_writeq(IMR_IP2_VAL,
 258                                      IOADDR(A_BCM1480_IMR_REGISTER(cpu,
 259                                                                    R_BCM1480_IMR_INTERRUPT_MAP_BASE_L) + (i << 3)));
 260                 }
 261         }
 262
 263         init_bcm1480_irqs();
 264
 265         /*
 266          * Map the high 16 bits of mailbox_0 registers to IP[3], for
 267          * inter-cpu messages
 268          */
 269         /* Was I1 */
 270         for (cpu = 0; cpu < 4; cpu++) {
 271                 __raw_writeq(IMR_IP3_VAL, IOADDR(A_BCM1480_IMR_REGISTER(cpu, R_BCM1480_IMR_INTERRUPT_MAP_BASE_H) +
 272                                                  (K_BCM1480_INT_MBOX_0_0 << 3)));
 273         }
 274
 275
 276         /* Clear the mailboxes.  The firmware may leave them dirty */
 277         for (cpu = 0; cpu < 4; cpu++) {
 278                 __raw_writeq(0xffffffffffffffffULL,
 279                              IOADDR(A_BCM1480_IMR_REGISTER(cpu, R_BCM1480_IMR_MAILBOX_0_CLR_CPU)));
 280                 __raw_writeq(0xffffffffffffffffULL,
 281                              IOADDR(A_BCM1480_IMR_REGISTER(cpu, R_BCM1480_IMR_MAILBOX_1_CLR_CPU)));
 282         }
 283
 284
 285         /* Mask everything except the high 16 bit of mailbox_0 registers for all cpus */
 286         tmp = ~((u64) 0) ^ ( (((u64) 1) << K_BCM1480_INT_MBOX_0_0));
 287         for (cpu = 0; cpu < 4; cpu++) {
 288                 __raw_writeq(tmp, IOADDR(A_BCM1480_IMR_REGISTER(cpu, R_BCM1480_IMR_INTERRUPT_MASK_H)));
 289         }
 290         tmp = ~((u64) 0);
 291         for (cpu = 0; cpu < 4; cpu++) {
 292                 __raw_writeq(tmp, IOADDR(A_BCM1480_IMR_REGISTER(cpu, R_BCM1480_IMR_INTERRUPT_MASK_L)));
 293         }
 294
 295         /*
 296          * Note that the timer interrupts are also mapped, but this is
 297          * done in bcm1480_time_init().  Also, the profiling driver
 298          * does its own management of IP7.
 299          */
 300
 301         /* Enable necessary IPs, disable the rest */
 302         change_c0_status(ST0_IM, imask);
 303 }
 304
 305 extern void bcm1480_mailbox_interrupt(void);
 306
 307 static inline void dispatch_ip2(void)
 308 {
 309         unsigned long long mask_h, mask_l;
 310         unsigned int cpu = smp_processor_id();
 311         unsigned long base;
 312
 313         /*
 314          * Default...we've hit an IP[2] interrupt, which means we've got to
 315          * check the 1480 interrupt registers to figure out what to do.  Need
 316          * to detect which CPU we're on, now that smp_affinity is supported.
 317          */
 318         base = A_BCM1480_IMR_MAPPER(cpu);
 319         mask_h = __raw_readq(
 320                 IOADDR(base + R_BCM1480_IMR_INTERRUPT_STATUS_BASE_H));
 321         mask_l = __raw_readq(
 322                 IOADDR(base + R_BCM1480_IMR_INTERRUPT_STATUS_BASE_L));
 323
 324         if (mask_h) {
 325                 if (mask_h ^ 1)
 326                         do_IRQ(fls64(mask_h) - 1);
 327                 else if (mask_l)
 328                         do_IRQ(63 + fls64(mask_l));
 329         }
 330 }
 331
 332 asmlinkage void plat_irq_dispatch(void)
 333 {
 334         unsigned int cpu = smp_processor_id();
 335         unsigned int pending;
 336
 337         pending = read_c0_cause() & read_c0_status();
 338
 339         if (pending & CAUSEF_IP4)
 340                 do_IRQ(K_BCM1480_INT_TIMER_0 + cpu);
 341 #ifdef CONFIG_SMP
 342         else if (pending & CAUSEF_IP3)
 343                 bcm1480_mailbox_interrupt();
 344 #endif
 345
 346         else if (pending & CAUSEF_IP2)
 347                 dispatch_ip2();
 348 }