arch/powerpc/platforms/cell/interrupt.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Cell Internal Interrupt Controller
   4  *
   5  * Copyright (C) 2006 Benjamin Herrenschmidt (benh@kernel.crashing.org)
   6  *                    IBM, Corp.
   7  *
   8  * (C) Copyright IBM Deutschland Entwicklung GmbH 2005
   9  *
  10  * Author: Arnd Bergmann <arndb@de.ibm.com>
  11  *
  12  * TODO:
  13  * - Fix various assumptions related to HW CPU numbers vs. linux CPU numbers
  14  *   vs node numbers in the setup code
  15  * - Implement proper handling of maxcpus=1/2 (that is, routing of irqs from
  16  *   a non-active node to the active node)
  17  */
  18
  19 #include <linux/interrupt.h>
  20 #include <linux/irq.h>
  21 #include <linux/export.h>
  22 #include <linux/percpu.h>
  23 #include <linux/types.h>
  24 #include <linux/ioport.h>
  25 #include <linux/kernel_stat.h>
  26 #include <linux/pgtable.h>
  27
  28 #include <asm/io.h>
  29 #include <asm/prom.h>
  30 #include <asm/ptrace.h>
  31 #include <asm/machdep.h>
  32 #include <asm/cell-regs.h>
  33
  34 #include "interrupt.h"
  35
  36 struct iic {
  37         struct cbe_iic_thread_regs __iomem *regs;
  38         u8 target_id;
  39         u8 eoi_stack[16];
  40         int eoi_ptr;
  41         struct device_node *node;
  42 };
  43
  44 static DEFINE_PER_CPU(struct iic, cpu_iic);
  45 #define IIC_NODE_COUNT  2
  46 static struct irq_domain *iic_host;
  47
  48 /* Convert between "pending" bits and hw irq number */
  49 static irq_hw_number_t iic_pending_to_hwnum(struct cbe_iic_pending_bits bits)
  50 {
  51         unsigned char unit = bits.source & 0xf;
  52         unsigned char node = bits.source >> 4;
  53         unsigned char class = bits.class & 3;
  54
  55         /* Decode IPIs */
  56         if (bits.flags & CBE_IIC_IRQ_IPI)
  57                 return IIC_IRQ_TYPE_IPI | (bits.prio >> 4);
  58         else
  59                 return (node << IIC_IRQ_NODE_SHIFT) | (class << 4) | unit;
  60 }
  61
  62 static void iic_mask(struct irq_data *d)
  63 {
  64 }
  65
  66 static void iic_unmask(struct irq_data *d)
  67 {
  68 }
  69
  70 static void iic_eoi(struct irq_data *d)
  71 {
  72         struct iic *iic = this_cpu_ptr(&cpu_iic);
  73         out_be64(&iic->regs->prio, iic->eoi_stack[--iic->eoi_ptr]);
  74         BUG_ON(iic->eoi_ptr < 0);
  75 }
  76
  77 static struct irq_chip iic_chip = {
  78         .name = "CELL-IIC",
  79         .irq_mask = iic_mask,
  80         .irq_unmask = iic_unmask,
  81         .irq_eoi = iic_eoi,
  82 };
  83
  84
  85 static void iic_ioexc_eoi(struct irq_data *d)
  86 {
  87 }
  88
  89 static void iic_ioexc_cascade(struct irq_desc *desc)
  90 {
  91         struct irq_chip *chip = irq_desc_get_chip(desc);
  92         struct cbe_iic_regs __iomem *node_iic =
  93                 (void __iomem *)irq_desc_get_handler_data(desc);
  94         unsigned int irq = irq_desc_get_irq(desc);
  95         unsigned int base = (irq & 0xffffff00) | IIC_IRQ_TYPE_IOEXC;
  96         unsigned long bits, ack;
  97         int cascade;
  98
  99         for (;;) {
 100                 bits = in_be64(&node_iic->iic_is);
 101                 if (bits == 0)
 102                         break;
 103                 /* pre-ack edge interrupts */
 104                 ack = bits & IIC_ISR_EDGE_MASK;
 105                 if (ack)
 106                         out_be64(&node_iic->iic_is, ack);
 107                 /* handle them */
 108                 for (cascade = 63; cascade >= 0; cascade--)
 109                         if (bits & (0x8000000000000000UL >> cascade)) {
 110                                 unsigned int cirq =
 111                                         irq_linear_revmap(iic_host,
 112                                                           base | cascade);
 113                                 if (cirq)
 114                                         generic_handle_irq(cirq);
 115                         }
 116                 /* post-ack level interrupts */
 117                 ack = bits & ~IIC_ISR_EDGE_MASK;
 118                 if (ack)
 119                         out_be64(&node_iic->iic_is, ack);
 120         }
 121         chip->irq_eoi(&desc->irq_data);
 122 }
 123
 124
 125 static struct irq_chip iic_ioexc_chip = {
 126         .name = "CELL-IOEX",
 127         .irq_mask = iic_mask,
 128         .irq_unmask = iic_unmask,
 129         .irq_eoi = iic_ioexc_eoi,
 130 };
 131
 132 /* Get an IRQ number from the pending state register of the IIC */
 133 static unsigned int iic_get_irq(void)
 134 {
 135         struct cbe_iic_pending_bits pending;
 136         struct iic *iic;
 137         unsigned int virq;
 138
 139         iic = this_cpu_ptr(&cpu_iic);
 140         *(unsigned long *) &pending =
 141                 in_be64((u64 __iomem *) &iic->regs->pending_destr);
 142         if (!(pending.flags & CBE_IIC_IRQ_VALID))
 143                 return 0;
 144         virq = irq_linear_revmap(iic_host, iic_pending_to_hwnum(pending));
 145         if (!virq)
 146                 return 0;
 147         iic->eoi_stack[++iic->eoi_ptr] = pending.prio;
 148         BUG_ON(iic->eoi_ptr > 15);
 149         return virq;
 150 }
 151
 152 void iic_setup_cpu(void)
 153 {
 154         out_be64(&this_cpu_ptr(&cpu_iic)->regs->prio, 0xff);
 155 }
 156
 157 u8 iic_get_target_id(int cpu)
 158 {
 159         return per_cpu(cpu_iic, cpu).target_id;
 160 }
 161
 162 EXPORT_SYMBOL_GPL(iic_get_target_id);
 163
 164 #ifdef CONFIG_SMP
 165
 166 /* Use the highest interrupt priorities for IPI */
 167 static inline int iic_msg_to_irq(int msg)
 168 {
 169         return IIC_IRQ_TYPE_IPI + 0xf - msg;
 170 }
 171
 172 void iic_message_pass(int cpu, int msg)
 173 {
 174         out_be64(&per_cpu(cpu_iic, cpu).regs->generate, (0xf - msg) << 4);
 175 }
 176
 177 static void iic_request_ipi(int msg)
 178 {
 179         int virq;
 180
 181         virq = irq_create_mapping(iic_host, iic_msg_to_irq(msg));
 182         if (!virq) {
 183                 printk(KERN_ERR
 184                        "iic: failed to map IPI %s\n", smp_ipi_name[msg]);
 185                 return;
 186         }
 187
 188         /*
 189          * If smp_request_message_ipi encounters an error it will notify
 190          * the error.  If a message is not needed it will return non-zero.
 191          */
 192         if (smp_request_message_ipi(virq, msg))
 193                 irq_dispose_mapping(virq);
 194 }
 195
 196 void iic_request_IPIs(void)
 197 {
 198         iic_request_ipi(PPC_MSG_CALL_FUNCTION);
 199         iic_request_ipi(PPC_MSG_RESCHEDULE);
 200         iic_request_ipi(PPC_MSG_TICK_BROADCAST);
 201         iic_request_ipi(PPC_MSG_NMI_IPI);
 202 }
 203
 204 #endif /* CONFIG_SMP */
 205
 206
 207 static int iic_host_match(struct irq_domain *h, struct device_node *node,
 208                           enum irq_domain_bus_token bus_token)
 209 {
 210         return of_device_is_compatible(node,
 211                                     "IBM,CBEA-Internal-Interrupt-Controller");
 212 }
 213
 214 static int iic_host_map(struct irq_domain *h, unsigned int virq,
 215                         irq_hw_number_t hw)
 216 {
 217         switch (hw & IIC_IRQ_TYPE_MASK) {
 218         case IIC_IRQ_TYPE_IPI:
 219                 irq_set_chip_and_handler(virq, &iic_chip, handle_percpu_irq);
 220                 break;
 221         case IIC_IRQ_TYPE_IOEXC:
 222                 irq_set_chip_and_handler(virq, &iic_ioexc_chip,
 223                                          handle_edge_eoi_irq);
 224                 break;
 225         default:
 226                 irq_set_chip_and_handler(virq, &iic_chip, handle_edge_eoi_irq);
 227         }
 228         return 0;
 229 }
 230
 231 static int iic_host_xlate(struct irq_domain *h, struct device_node *ct,
 232                            const u32 *intspec, unsigned int intsize,
 233                            irq_hw_number_t *out_hwirq, unsigned int *out_flags)
 234
 235 {
 236         unsigned int node, ext, unit, class;
 237         const u32 *val;
 238
 239         if (!of_device_is_compatible(ct,
 240                                      "IBM,CBEA-Internal-Interrupt-Controller"))
 241                 return -ENODEV;
 242         if (intsize != 1)
 243                 return -ENODEV;
 244         val = of_get_property(ct, "#interrupt-cells", NULL);
 245         if (val == NULL || *val != 1)
 246                 return -ENODEV;
 247
 248         node = intspec[0] >> 24;
 249         ext = (intspec[0] >> 16) & 0xff;
 250         class = (intspec[0] >> 8) & 0xff;
 251         unit = intspec[0] & 0xff;
 252
 253         /* Check if node is in supported range */
 254         if (node > 1)
 255                 return -EINVAL;
 256
 257         /* Build up interrupt number, special case for IO exceptions */
 258         *out_hwirq = (node << IIC_IRQ_NODE_SHIFT);
 259         if (unit == IIC_UNIT_IIC && class == 1)
 260                 *out_hwirq |= IIC_IRQ_TYPE_IOEXC | ext;
 261         else
 262                 *out_hwirq |= IIC_IRQ_TYPE_NORMAL |
 263                         (class << IIC_IRQ_CLASS_SHIFT) | unit;
 264
 265         /* Dummy flags, ignored by iic code */
 266         *out_flags = IRQ_TYPE_EDGE_RISING;
 267
 268         return 0;
 269 }
 270
 271 static const struct irq_domain_ops iic_host_ops = {
 272         .match = iic_host_match,
 273         .map = iic_host_map,
 274         .xlate = iic_host_xlate,
 275 };
 276
 277 static void __init init_one_iic(unsigned int hw_cpu, unsigned long addr,
 278                                 struct device_node *node)
 279 {
 280         /* XXX FIXME: should locate the linux CPU number from the HW cpu
 281          * number properly. We are lucky for now
 282          */
 283         struct iic *iic = &per_cpu(cpu_iic, hw_cpu);
 284
 285         iic->regs = ioremap(addr, sizeof(struct cbe_iic_thread_regs));
 286         BUG_ON(iic->regs == NULL);
 287
 288         iic->target_id = ((hw_cpu & 2) << 3) | ((hw_cpu & 1) ? 0xf : 0xe);
 289         iic->eoi_stack[0] = 0xff;
 290         iic->node = of_node_get(node);
 291         out_be64(&iic->regs->prio, 0);
 292
 293         printk(KERN_INFO "IIC for CPU %d target id 0x%x : %pOF\n",
 294                hw_cpu, iic->target_id, node);
 295 }
 296
 297 static int __init setup_iic(void)
 298 {
 299         struct device_node *dn;
 300         struct resource r0, r1;
 301         unsigned int node, cascade, found = 0;
 302         struct cbe_iic_regs __iomem *node_iic;
 303         const u32 *np;
 304
 305         for_each_node_by_name(dn, "interrupt-controller") {
 306                 if (!of_device_is_compatible(dn,
 307                                      "IBM,CBEA-Internal-Interrupt-Controller"))
 308                         continue;
 309                 np = of_get_property(dn, "ibm,interrupt-server-ranges", NULL);
 310                 if (np == NULL) {
 311                         printk(KERN_WARNING "IIC: CPU association not found\n");
 312                         of_node_put(dn);
 313                         return -ENODEV;
 314                 }
 315                 if (of_address_to_resource(dn, 0, &r0) ||
 316                     of_address_to_resource(dn, 1, &r1)) {
 317                         printk(KERN_WARNING "IIC: Can't resolve addresses\n");
 318                         of_node_put(dn);
 319                         return -ENODEV;
 320                 }
 321                 found++;
 322                 init_one_iic(np[0], r0.start, dn);
 323                 init_one_iic(np[1], r1.start, dn);
 324
 325                 /* Setup cascade for IO exceptions. XXX cleanup tricks to get
 326                  * node vs CPU etc...
 327                  * Note that we configure the IIC_IRR here with a hard coded
 328                  * priority of 1. We might want to improve that later.
 329                  */
 330                 node = np[0] >> 1;
 331                 node_iic = cbe_get_cpu_iic_regs(np[0]);
 332                 cascade = node << IIC_IRQ_NODE_SHIFT;
 333                 cascade |= 1 << IIC_IRQ_CLASS_SHIFT;
 334                 cascade |= IIC_UNIT_IIC;
 335                 cascade = irq_create_mapping(iic_host, cascade);
 336                 if (!cascade)
 337                         continue;
 338                 /*
 339                  * irq_data is a generic pointer that gets passed back
 340                  * to us later, so the forced cast is fine.
 341                  */
 342                 irq_set_handler_data(cascade, (void __force *)node_iic);
 343                 irq_set_chained_handler(cascade, iic_ioexc_cascade);
 344                 out_be64(&node_iic->iic_ir,
 345                          (1 << 12)              /* priority */ |
 346                          (node << 4)            /* dest node */ |
 347                          IIC_UNIT_THREAD_0      /* route them to thread 0 */);
 348                 /* Flush pending (make sure it triggers if there is
 349                  * anything pending
 350                  */
 351                 out_be64(&node_iic->iic_is, 0xfffffffffffffffful);
 352         }
 353
 354         if (found)
 355                 return 0;
 356         else
 357                 return -ENODEV;
 358 }
 359
 360 void __init iic_init_IRQ(void)
 361 {
 362         /* Setup an irq host data structure */
 363         iic_host = irq_domain_add_linear(NULL, IIC_SOURCE_COUNT, &iic_host_ops,
 364                                          NULL);
 365         BUG_ON(iic_host == NULL);
 366         irq_set_default_host(iic_host);
 367
 368         /* Discover and initialize iics */
 369         if (setup_iic() < 0)
 370                 panic("IIC: Failed to initialize !\n");
 371
 372         /* Set master interrupt handling function */
 373         ppc_md.get_irq = iic_get_irq;
 374
 375         /* Enable on current CPU */
 376         iic_setup_cpu();
 377 }
 378
 379 void iic_set_interrupt_routing(int cpu, int thread, int priority)
 380 {
 381         struct cbe_iic_regs __iomem *iic_regs = cbe_get_cpu_iic_regs(cpu);
 382         u64 iic_ir = 0;
 383         int node = cpu >> 1;
 384
 385         /* Set which node and thread will handle the next interrupt */
 386         iic_ir |= CBE_IIC_IR_PRIO(priority) |
 387                   CBE_IIC_IR_DEST_NODE(node);
 388         if (thread == 0)
 389                 iic_ir |= CBE_IIC_IR_DEST_UNIT(CBE_IIC_IR_PT_0);
 390         else
 391                 iic_ir |= CBE_IIC_IR_DEST_UNIT(CBE_IIC_IR_PT_1);
 392         out_be64(&iic_regs->iic_ir, iic_ir);
 393 }