arch/powerpc/platforms/cell/interrupt.c

   1 /*
   2  * Cell Internal Interrupt Controller
   3  *
   4  * Copyright (C) 2006 Benjamin Herrenschmidt (benh@kernel.crashing.org)
   5  *                    IBM, Corp.
   6  *
   7  * (C) Copyright IBM Deutschland Entwicklung GmbH 2005
   8  *
   9  * Author: Arnd Bergmann <arndb@de.ibm.com>
  10  *
  11  * This program is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License as published by
  13  * the Free Software Foundation; either version 2, or (at your option)
  14  * any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  * GNU General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with this program; if not, write to the Free Software
  23  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  24  *
  25  * TODO:
  26  * - Fix various assumptions related to HW CPU numbers vs. linux CPU numbers
  27  *   vs node numbers in the setup code
  28  * - Implement proper handling of maxcpus=1/2 (that is, routing of irqs from
  29  *   a non-active node to the active node)
  30  */
  31
  32 #include <linux/interrupt.h>
  33 #include <linux/irq.h>
  34 #include <linux/module.h>
  35 #include <linux/percpu.h>
  36 #include <linux/types.h>
  37 #include <linux/ioport.h>
  38 #include <linux/kernel_stat.h>
  39
  40 #include <asm/io.h>
  41 #include <asm/pgtable.h>
  42 #include <asm/prom.h>
  43 #include <asm/ptrace.h>
  44 #include <asm/machdep.h>
  45 #include <asm/cell-regs.h>
  46
  47 #include "interrupt.h"
  48
  49 struct iic {
  50         struct cbe_iic_thread_regs __iomem *regs;
  51         u8 target_id;
  52         u8 eoi_stack[16];
  53         int eoi_ptr;
  54         struct device_node *node;
  55 };
  56
  57 static DEFINE_PER_CPU(struct iic, cpu_iic);
  58 #define IIC_NODE_COUNT  2
  59 static struct irq_host *iic_host;
  60
  61 /* Convert between "pending" bits and hw irq number */
  62 static irq_hw_number_t iic_pending_to_hwnum(struct cbe_iic_pending_bits bits)
  63 {
  64         unsigned char unit = bits.source & 0xf;
  65         unsigned char node = bits.source >> 4;
  66         unsigned char class = bits.class & 3;
  67
  68         /* Decode IPIs */
  69         if (bits.flags & CBE_IIC_IRQ_IPI)
  70                 return IIC_IRQ_TYPE_IPI | (bits.prio >> 4);
  71         else
  72                 return (node << IIC_IRQ_NODE_SHIFT) | (class << 4) | unit;
  73 }
  74
  75 static void iic_mask(struct irq_data *d)
  76 {
  77 }
  78
  79 static void iic_unmask(struct irq_data *d)
  80 {
  81 }
  82
  83 static void iic_eoi(struct irq_data *d)
  84 {
  85         struct iic *iic = &__get_cpu_var(cpu_iic);
  86         out_be64(&iic->regs->prio, iic->eoi_stack[--iic->eoi_ptr]);
  87         BUG_ON(iic->eoi_ptr < 0);
  88 }
  89
  90 static struct irq_chip iic_chip = {
  91         .name = "CELL-IIC",
  92         .irq_mask = iic_mask,
  93         .irq_unmask = iic_unmask,
  94         .irq_eoi = iic_eoi,
  95 };
  96
  97
  98 static void iic_ioexc_eoi(struct irq_data *d)
  99 {
 100 }
 101
 102 static void iic_ioexc_cascade(unsigned int irq, struct irq_desc *desc)
 103 {
 104         struct irq_chip *chip = get_irq_desc_chip(desc);
 105         struct cbe_iic_regs __iomem *node_iic =
 106                 (void __iomem *)get_irq_desc_data(desc);
 107         unsigned int base = (irq & 0xffffff00) | IIC_IRQ_TYPE_IOEXC;
 108         unsigned long bits, ack;
 109         int cascade;
 110
 111         for (;;) {
 112                 bits = in_be64(&node_iic->iic_is);
 113                 if (bits == 0)
 114                         break;
 115                 /* pre-ack edge interrupts */
 116                 ack = bits & IIC_ISR_EDGE_MASK;
 117                 if (ack)
 118                         out_be64(&node_iic->iic_is, ack);
 119                 /* handle them */
 120                 for (cascade = 63; cascade >= 0; cascade--)
 121                         if (bits & (0x8000000000000000UL >> cascade)) {
 122                                 unsigned int cirq =
 123                                         irq_linear_revmap(iic_host,
 124                                                           base | cascade);
 125                                 if (cirq != NO_IRQ)
 126                                         generic_handle_irq(cirq);
 127                         }
 128                 /* post-ack level interrupts */
 129                 ack = bits & ~IIC_ISR_EDGE_MASK;
 130                 if (ack)
 131                         out_be64(&node_iic->iic_is, ack);
 132         }
 133         chip->irq_eoi(&desc->irq_data);
 134 }
 135
 136
 137 static struct irq_chip iic_ioexc_chip = {
 138         .name = "CELL-IOEX",
 139         .irq_mask = iic_mask,
 140         .irq_unmask = iic_unmask,
 141         .irq_eoi = iic_ioexc_eoi,
 142 };
 143
 144 /* Get an IRQ number from the pending state register of the IIC */
 145 static unsigned int iic_get_irq(void)
 146 {
 147         struct cbe_iic_pending_bits pending;
 148         struct iic *iic;
 149         unsigned int virq;
 150
 151         iic = &__get_cpu_var(cpu_iic);
 152         *(unsigned long *) &pending =
 153                 in_be64((u64 __iomem *) &iic->regs->pending_destr);
 154         if (!(pending.flags & CBE_IIC_IRQ_VALID))
 155                 return NO_IRQ;
 156         virq = irq_linear_revmap(iic_host, iic_pending_to_hwnum(pending));
 157         if (virq == NO_IRQ)
 158                 return NO_IRQ;
 159         iic->eoi_stack[++iic->eoi_ptr] = pending.prio;
 160         BUG_ON(iic->eoi_ptr > 15);
 161         return virq;
 162 }
 163
 164 void iic_setup_cpu(void)
 165 {
 166         out_be64(&__get_cpu_var(cpu_iic).regs->prio, 0xff);
 167 }
 168
 169 u8 iic_get_target_id(int cpu)
 170 {
 171         return per_cpu(cpu_iic, cpu).target_id;
 172 }
 173
 174 EXPORT_SYMBOL_GPL(iic_get_target_id);
 175
 176 #ifdef CONFIG_SMP
 177
 178 /* Use the highest interrupt priorities for IPI */
 179 static inline int iic_ipi_to_irq(int ipi)
 180 {
 181         return IIC_IRQ_TYPE_IPI + 0xf - ipi;
 182 }
 183
 184 void iic_cause_IPI(int cpu, int mesg)
 185 {
 186         out_be64(&per_cpu(cpu_iic, cpu).regs->generate, (0xf - mesg) << 4);
 187 }
 188
 189 struct irq_host *iic_get_irq_host(int node)
 190 {
 191         return iic_host;
 192 }
 193 EXPORT_SYMBOL_GPL(iic_get_irq_host);
 194
 195 static irqreturn_t iic_ipi_action(int irq, void *dev_id)
 196 {
 197         int ipi = (int)(long)dev_id;
 198
 199         smp_message_recv(ipi);
 200
 201         return IRQ_HANDLED;
 202 }
 203 static void iic_request_ipi(int ipi, const char *name)
 204 {
 205         int virq;
 206
 207         virq = irq_create_mapping(iic_host, iic_ipi_to_irq(ipi));
 208         if (virq == NO_IRQ) {
 209                 printk(KERN_ERR
 210                        "iic: failed to map IPI %s\n", name);
 211                 return;
 212         }
 213         if (request_irq(virq, iic_ipi_action, IRQF_DISABLED, name,
 214                         (void *)(long)ipi))
 215                 printk(KERN_ERR
 216                        "iic: failed to request IPI %s\n", name);
 217 }
 218
 219 void iic_request_IPIs(void)
 220 {
 221         iic_request_ipi(PPC_MSG_CALL_FUNCTION, "IPI-call");
 222         iic_request_ipi(PPC_MSG_RESCHEDULE, "IPI-resched");
 223         iic_request_ipi(PPC_MSG_CALL_FUNC_SINGLE, "IPI-call-single");
 224 #ifdef CONFIG_DEBUGGER
 225         iic_request_ipi(PPC_MSG_DEBUGGER_BREAK, "IPI-debug");
 226 #endif /* CONFIG_DEBUGGER */
 227 }
 228
 229 #endif /* CONFIG_SMP */
 230
 231
 232 static int iic_host_match(struct irq_host *h, struct device_node *node)
 233 {
 234         return of_device_is_compatible(node,
 235                                     "IBM,CBEA-Internal-Interrupt-Controller");
 236 }
 237
 238 extern int noirqdebug;
 239
 240 static void handle_iic_irq(unsigned int irq, struct irq_desc *desc)
 241 {
 242         struct irq_chip *chip = get_irq_desc_chip(desc);
 243
 244         raw_spin_lock(&desc->lock);
 245
 246         desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
 247
 248         /*
 249          * If we're currently running this IRQ, or its disabled,
 250          * we shouldn't process the IRQ. Mark it pending, handle
 251          * the necessary masking and go out
 252          */
 253         if (unlikely((desc->status & (IRQ_INPROGRESS | IRQ_DISABLED)) ||
 254                     !desc->action)) {
 255                 desc->status |= IRQ_PENDING;
 256                 goto out_eoi;
 257         }
 258
 259         kstat_incr_irqs_this_cpu(irq, desc);
 260
 261         /* Mark the IRQ currently in progress.*/
 262         desc->status |= IRQ_INPROGRESS;
 263
 264         do {
 265                 struct irqaction *action = desc->action;
 266                 irqreturn_t action_ret;
 267
 268                 if (unlikely(!action))
 269                         goto out_eoi;
 270
 271                 desc->status &= ~IRQ_PENDING;
 272                 raw_spin_unlock(&desc->lock);
 273                 action_ret = handle_IRQ_event(irq, action);
 274                 if (!noirqdebug)
 275                         note_interrupt(irq, desc, action_ret);
 276                 raw_spin_lock(&desc->lock);
 277
 278         } while ((desc->status & (IRQ_PENDING | IRQ_DISABLED)) == IRQ_PENDING);
 279
 280         desc->status &= ~IRQ_INPROGRESS;
 281 out_eoi:
 282         chip->irq_eoi(&desc->irq_data);
 283         raw_spin_unlock(&desc->lock);
 284 }
 285
 286 static int iic_host_map(struct irq_host *h, unsigned int virq,
 287                         irq_hw_number_t hw)
 288 {
 289         switch (hw & IIC_IRQ_TYPE_MASK) {
 290         case IIC_IRQ_TYPE_IPI:
 291                 set_irq_chip_and_handler(virq, &iic_chip, handle_percpu_irq);
 292                 break;
 293         case IIC_IRQ_TYPE_IOEXC:
 294                 set_irq_chip_and_handler(virq, &iic_ioexc_chip,
 295                                          handle_iic_irq);
 296                 break;
 297         default:
 298                 set_irq_chip_and_handler(virq, &iic_chip, handle_iic_irq);
 299         }
 300         return 0;
 301 }
 302
 303 static int iic_host_xlate(struct irq_host *h, struct device_node *ct,
 304                            const u32 *intspec, unsigned int intsize,
 305                            irq_hw_number_t *out_hwirq, unsigned int *out_flags)
 306
 307 {
 308         unsigned int node, ext, unit, class;
 309         const u32 *val;
 310
 311         if (!of_device_is_compatible(ct,
 312                                      "IBM,CBEA-Internal-Interrupt-Controller"))
 313                 return -ENODEV;
 314         if (intsize != 1)
 315                 return -ENODEV;
 316         val = of_get_property(ct, "#interrupt-cells", NULL);
 317         if (val == NULL || *val != 1)
 318                 return -ENODEV;
 319
 320         node = intspec[0] >> 24;
 321         ext = (intspec[0] >> 16) & 0xff;
 322         class = (intspec[0] >> 8) & 0xff;
 323         unit = intspec[0] & 0xff;
 324
 325         /* Check if node is in supported range */
 326         if (node > 1)
 327                 return -EINVAL;
 328
 329         /* Build up interrupt number, special case for IO exceptions */
 330         *out_hwirq = (node << IIC_IRQ_NODE_SHIFT);
 331         if (unit == IIC_UNIT_IIC && class == 1)
 332                 *out_hwirq |= IIC_IRQ_TYPE_IOEXC | ext;
 333         else
 334                 *out_hwirq |= IIC_IRQ_TYPE_NORMAL |
 335                         (class << IIC_IRQ_CLASS_SHIFT) | unit;
 336
 337         /* Dummy flags, ignored by iic code */
 338         *out_flags = IRQ_TYPE_EDGE_RISING;
 339
 340         return 0;
 341 }
 342
 343 static struct irq_host_ops iic_host_ops = {
 344         .match = iic_host_match,
 345         .map = iic_host_map,
 346         .xlate = iic_host_xlate,
 347 };
 348
 349 static void __init init_one_iic(unsigned int hw_cpu, unsigned long addr,
 350                                 struct device_node *node)
 351 {
 352         /* XXX FIXME: should locate the linux CPU number from the HW cpu
 353          * number properly. We are lucky for now
 354          */
 355         struct iic *iic = &per_cpu(cpu_iic, hw_cpu);
 356
 357         iic->regs = ioremap(addr, sizeof(struct cbe_iic_thread_regs));
 358         BUG_ON(iic->regs == NULL);
 359
 360         iic->target_id = ((hw_cpu & 2) << 3) | ((hw_cpu & 1) ? 0xf : 0xe);
 361         iic->eoi_stack[0] = 0xff;
 362         iic->node = of_node_get(node);
 363         out_be64(&iic->regs->prio, 0);
 364
 365         printk(KERN_INFO "IIC for CPU %d target id 0x%x : %s\n",
 366                hw_cpu, iic->target_id, node->full_name);
 367 }
 368
 369 static int __init setup_iic(void)
 370 {
 371         struct device_node *dn;
 372         struct resource r0, r1;
 373         unsigned int node, cascade, found = 0;
 374         struct cbe_iic_regs __iomem *node_iic;
 375         const u32 *np;
 376
 377         for (dn = NULL;
 378              (dn = of_find_node_by_name(dn,"interrupt-controller")) != NULL;) {
 379                 if (!of_device_is_compatible(dn,
 380                                      "IBM,CBEA-Internal-Interrupt-Controller"))
 381                         continue;
 382                 np = of_get_property(dn, "ibm,interrupt-server-ranges", NULL);
 383                 if (np == NULL) {
 384                         printk(KERN_WARNING "IIC: CPU association not found\n");
 385                         of_node_put(dn);
 386                         return -ENODEV;
 387                 }
 388                 if (of_address_to_resource(dn, 0, &r0) ||
 389                     of_address_to_resource(dn, 1, &r1)) {
 390                         printk(KERN_WARNING "IIC: Can't resolve addresses\n");
 391                         of_node_put(dn);
 392                         return -ENODEV;
 393                 }
 394                 found++;
 395                 init_one_iic(np[0], r0.start, dn);
 396                 init_one_iic(np[1], r1.start, dn);
 397
 398                 /* Setup cascade for IO exceptions. XXX cleanup tricks to get
 399                  * node vs CPU etc...
 400                  * Note that we configure the IIC_IRR here with a hard coded
 401                  * priority of 1. We might want to improve that later.
 402                  */
 403                 node = np[0] >> 1;
 404                 node_iic = cbe_get_cpu_iic_regs(np[0]);
 405                 cascade = node << IIC_IRQ_NODE_SHIFT;
 406                 cascade |= 1 << IIC_IRQ_CLASS_SHIFT;
 407                 cascade |= IIC_UNIT_IIC;
 408                 cascade = irq_create_mapping(iic_host, cascade);
 409                 if (cascade == NO_IRQ)
 410                         continue;
 411                 /*
 412                  * irq_data is a generic pointer that gets passed back
 413                  * to us later, so the forced cast is fine.
 414                  */
 415                 set_irq_data(cascade, (void __force *)node_iic);
 416                 set_irq_chained_handler(cascade , iic_ioexc_cascade);
 417                 out_be64(&node_iic->iic_ir,
 418                          (1 << 12)              /* priority */ |
 419                          (node << 4)            /* dest node */ |
 420                          IIC_UNIT_THREAD_0      /* route them to thread 0 */);
 421                 /* Flush pending (make sure it triggers if there is
 422                  * anything pending
 423                  */
 424                 out_be64(&node_iic->iic_is, 0xfffffffffffffffful);
 425         }
 426
 427         if (found)
 428                 return 0;
 429         else
 430                 return -ENODEV;
 431 }
 432
 433 void __init iic_init_IRQ(void)
 434 {
 435         /* Setup an irq host data structure */
 436         iic_host = irq_alloc_host(NULL, IRQ_HOST_MAP_LINEAR, IIC_SOURCE_COUNT,
 437                                   &iic_host_ops, IIC_IRQ_INVALID);
 438         BUG_ON(iic_host == NULL);
 439         irq_set_default_host(iic_host);
 440
 441         /* Discover and initialize iics */
 442         if (setup_iic() < 0)
 443                 panic("IIC: Failed to initialize !\n");
 444
 445         /* Set master interrupt handling function */
 446         ppc_md.get_irq = iic_get_irq;
 447
 448         /* Enable on current CPU */
 449         iic_setup_cpu();
 450 }
 451
 452 void iic_set_interrupt_routing(int cpu, int thread, int priority)
 453 {
 454         struct cbe_iic_regs __iomem *iic_regs = cbe_get_cpu_iic_regs(cpu);
 455         u64 iic_ir = 0;
 456         int node = cpu >> 1;
 457
 458         /* Set which node and thread will handle the next interrupt */
 459         iic_ir |= CBE_IIC_IR_PRIO(priority) |
 460                   CBE_IIC_IR_DEST_NODE(node);
 461         if (thread == 0)
 462                 iic_ir |= CBE_IIC_IR_DEST_UNIT(CBE_IIC_IR_PT_0);
 463         else
 464                 iic_ir |= CBE_IIC_IR_DEST_UNIT(CBE_IIC_IR_PT_1);
 465         out_be64(&iic_regs->iic_ir, iic_ir);
 466 }