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   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, 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(unsigned int irq)
  76 {
  77 }
  78
  79 static void iic_unmask(unsigned int irq)
  80 {
  81 }
  82
  83 static void iic_eoi(unsigned int irq)
  84 {
  85         struct iic *iic = &__get_cpu_var(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         .typename = " CELL-IIC ",
  92         .mask = iic_mask,
  93         .unmask = iic_unmask,
  94         .eoi = iic_eoi,
  95 };
  96
  97
  98 static void iic_ioexc_eoi(unsigned int irq)
  99 {
 100 }
 101
 102 static void iic_ioexc_cascade(unsigned int irq, struct irq_desc *desc)
 103 {
 104         struct cbe_iic_regs __iomem *node_iic = (void __iomem *)desc->handler_data;
 105         unsigned int base = (irq & 0xffffff00) | IIC_IRQ_TYPE_IOEXC;
 106         unsigned long bits, ack;
 107         int cascade;
 108
 109         for (;;) {
 110                 bits = in_be64(&node_iic->iic_is);
 111                 if (bits == 0)
 112                         break;
 113                 /* pre-ack edge interrupts */
 114                 ack = bits & IIC_ISR_EDGE_MASK;
 115                 if (ack)
 116                         out_be64(&node_iic->iic_is, ack);
 117                 /* handle them */
 118                 for (cascade = 63; cascade >= 0; cascade--)
 119                         if (bits & (0x8000000000000000UL >> cascade)) {
 120                                 unsigned int cirq =
 121                                         irq_linear_revmap(iic_host,
 122                                                           base | cascade);
 123                                 if (cirq != NO_IRQ)
 124                                         generic_handle_irq(cirq);
 125                         }
 126                 /* post-ack level interrupts */
 127                 ack = bits & ~IIC_ISR_EDGE_MASK;
 128                 if (ack)
 129                         out_be64(&node_iic->iic_is, ack);
 130         }
 131         desc->chip->eoi(irq);
 132 }
 133
 134
 135 static struct irq_chip iic_ioexc_chip = {
 136         .typename = " CELL-IOEX",
 137         .mask = iic_mask,
 138         .unmask = iic_unmask,
 139         .eoi = iic_ioexc_eoi,
 140 };
 141
 142 /* Get an IRQ number from the pending state register of the IIC */
 143 static unsigned int iic_get_irq(void)
 144 {
 145         struct cbe_iic_pending_bits pending;
 146         struct iic *iic;
 147         unsigned int virq;
 148
 149         iic = &__get_cpu_var(iic);
 150         *(unsigned long *) &pending =
 151                 in_be64((u64 __iomem *) &iic->regs->pending_destr);
 152         if (!(pending.flags & CBE_IIC_IRQ_VALID))
 153                 return NO_IRQ;
 154         virq = irq_linear_revmap(iic_host, iic_pending_to_hwnum(pending));
 155         if (virq == NO_IRQ)
 156                 return NO_IRQ;
 157         iic->eoi_stack[++iic->eoi_ptr] = pending.prio;
 158         BUG_ON(iic->eoi_ptr > 15);
 159         return virq;
 160 }
 161
 162 void iic_setup_cpu(void)
 163 {
 164         out_be64(&__get_cpu_var(iic).regs->prio, 0xff);
 165 }
 166
 167 u8 iic_get_target_id(int cpu)
 168 {
 169         return per_cpu(iic, cpu).target_id;
 170 }
 171
 172 EXPORT_SYMBOL_GPL(iic_get_target_id);
 173
 174 #ifdef CONFIG_SMP
 175
 176 /* Use the highest interrupt priorities for IPI */
 177 static inline int iic_ipi_to_irq(int ipi)
 178 {
 179         return IIC_IRQ_TYPE_IPI + 0xf - ipi;
 180 }
 181
 182 void iic_cause_IPI(int cpu, int mesg)
 183 {
 184         out_be64(&per_cpu(iic, cpu).regs->generate, (0xf - mesg) << 4);
 185 }
 186
 187 struct irq_host *iic_get_irq_host(int node)
 188 {
 189         return iic_host;
 190 }
 191 EXPORT_SYMBOL_GPL(iic_get_irq_host);
 192
 193 static irqreturn_t iic_ipi_action(int irq, void *dev_id)
 194 {
 195         int ipi = (int)(long)dev_id;
 196
 197         smp_message_recv(ipi);
 198
 199         return IRQ_HANDLED;
 200 }
 201 static void iic_request_ipi(int ipi, const char *name)
 202 {
 203         int virq;
 204
 205         virq = irq_create_mapping(iic_host, iic_ipi_to_irq(ipi));
 206         if (virq == NO_IRQ) {
 207                 printk(KERN_ERR
 208                        "iic: failed to map IPI %s\n", name);
 209                 return;
 210         }
 211         if (request_irq(virq, iic_ipi_action, IRQF_DISABLED, name,
 212                         (void *)(long)ipi))
 213                 printk(KERN_ERR
 214                        "iic: failed to request IPI %s\n", name);
 215 }
 216
 217 void iic_request_IPIs(void)
 218 {
 219         iic_request_ipi(PPC_MSG_CALL_FUNCTION, "IPI-call");
 220         iic_request_ipi(PPC_MSG_RESCHEDULE, "IPI-resched");
 221         iic_request_ipi(PPC_MSG_CALL_FUNC_SINGLE, "IPI-call-single");
 222 #ifdef CONFIG_DEBUGGER
 223         iic_request_ipi(PPC_MSG_DEBUGGER_BREAK, "IPI-debug");
 224 #endif /* CONFIG_DEBUGGER */
 225 }
 226
 227 #endif /* CONFIG_SMP */
 228
 229
 230 static int iic_host_match(struct irq_host *h, struct device_node *node)
 231 {
 232         return of_device_is_compatible(node,
 233                                     "IBM,CBEA-Internal-Interrupt-Controller");
 234 }
 235
 236 extern int noirqdebug;
 237
 238 static void handle_iic_irq(unsigned int irq, struct irq_desc *desc)
 239 {
 240         const unsigned int cpu = smp_processor_id();
 241
 242         spin_lock(&desc->lock);
 243
 244         desc->status &= ~(IRQ_REPLAY | IRQ_WAITING);
 245
 246         /*
 247          * If we're currently running this IRQ, or its disabled,
 248          * we shouldn't process the IRQ. Mark it pending, handle
 249          * the necessary masking and go out
 250          */
 251         if (unlikely((desc->status & (IRQ_INPROGRESS | IRQ_DISABLED)) ||
 252                     !desc->action)) {
 253                 desc->status |= IRQ_PENDING;
 254                 goto out_eoi;
 255         }
 256
 257         kstat_cpu(cpu).irqs[irq]++;
 258
 259         /* Mark the IRQ currently in progress.*/
 260         desc->status |= IRQ_INPROGRESS;
 261
 262         do {
 263                 struct irqaction *action = desc->action;
 264                 irqreturn_t action_ret;
 265
 266                 if (unlikely(!action))
 267                         goto out_eoi;
 268
 269                 desc->status &= ~IRQ_PENDING;
 270                 spin_unlock(&desc->lock);
 271                 action_ret = handle_IRQ_event(irq, action);
 272                 if (!noirqdebug)
 273                         note_interrupt(irq, desc, action_ret);
 274                 spin_lock(&desc->lock);
 275
 276         } while ((desc->status & (IRQ_PENDING | IRQ_DISABLED)) == IRQ_PENDING);
 277
 278         desc->status &= ~IRQ_INPROGRESS;
 279 out_eoi:
 280         desc->chip->eoi(irq);
 281         spin_unlock(&desc->lock);
 282 }
 283
 284 static int iic_host_map(struct irq_host *h, unsigned int virq,
 285                         irq_hw_number_t hw)
 286 {
 287         switch (hw & IIC_IRQ_TYPE_MASK) {
 288         case IIC_IRQ_TYPE_IPI:
 289                 set_irq_chip_and_handler(virq, &iic_chip, handle_percpu_irq);
 290                 break;
 291         case IIC_IRQ_TYPE_IOEXC:
 292                 set_irq_chip_and_handler(virq, &iic_ioexc_chip,
 293                                          handle_iic_irq);
 294                 break;
 295         default:
 296                 set_irq_chip_and_handler(virq, &iic_chip, handle_iic_irq);
 297         }
 298         return 0;
 299 }
 300
 301 static int iic_host_xlate(struct irq_host *h, struct device_node *ct,
 302                            u32 *intspec, unsigned int intsize,
 303                            irq_hw_number_t *out_hwirq, unsigned int *out_flags)
 304
 305 {
 306         unsigned int node, ext, unit, class;
 307         const u32 *val;
 308
 309         if (!of_device_is_compatible(ct,
 310                                      "IBM,CBEA-Internal-Interrupt-Controller"))
 311                 return -ENODEV;
 312         if (intsize != 1)
 313                 return -ENODEV;
 314         val = of_get_property(ct, "#interrupt-cells", NULL);
 315         if (val == NULL || *val != 1)
 316                 return -ENODEV;
 317
 318         node = intspec[0] >> 24;
 319         ext = (intspec[0] >> 16) & 0xff;
 320         class = (intspec[0] >> 8) & 0xff;
 321         unit = intspec[0] & 0xff;
 322
 323         /* Check if node is in supported range */
 324         if (node > 1)
 325                 return -EINVAL;
 326
 327         /* Build up interrupt number, special case for IO exceptions */
 328         *out_hwirq = (node << IIC_IRQ_NODE_SHIFT);
 329         if (unit == IIC_UNIT_IIC && class == 1)
 330                 *out_hwirq |= IIC_IRQ_TYPE_IOEXC | ext;
 331         else
 332                 *out_hwirq |= IIC_IRQ_TYPE_NORMAL |
 333                         (class << IIC_IRQ_CLASS_SHIFT) | unit;
 334
 335         /* Dummy flags, ignored by iic code */
 336         *out_flags = IRQ_TYPE_EDGE_RISING;
 337
 338         return 0;
 339 }
 340
 341 static struct irq_host_ops iic_host_ops = {
 342         .match = iic_host_match,
 343         .map = iic_host_map,
 344         .xlate = iic_host_xlate,
 345 };
 346
 347 static void __init init_one_iic(unsigned int hw_cpu, unsigned long addr,
 348                                 struct device_node *node)
 349 {
 350         /* XXX FIXME: should locate the linux CPU number from the HW cpu
 351          * number properly. We are lucky for now
 352          */
 353         struct iic *iic = &per_cpu(iic, hw_cpu);
 354
 355         iic->regs = ioremap(addr, sizeof(struct cbe_iic_thread_regs));
 356         BUG_ON(iic->regs == NULL);
 357
 358         iic->target_id = ((hw_cpu & 2) << 3) | ((hw_cpu & 1) ? 0xf : 0xe);
 359         iic->eoi_stack[0] = 0xff;
 360         iic->node = of_node_get(node);
 361         out_be64(&iic->regs->prio, 0);
 362
 363         printk(KERN_INFO "IIC for CPU %d target id 0x%x : %s\n",
 364                hw_cpu, iic->target_id, node->full_name);
 365 }
 366
 367 static int __init setup_iic(void)
 368 {
 369         struct device_node *dn;
 370         struct resource r0, r1;
 371         unsigned int node, cascade, found = 0;
 372         struct cbe_iic_regs __iomem *node_iic;
 373         const u32 *np;
 374
 375         for (dn = NULL;
 376              (dn = of_find_node_by_name(dn,"interrupt-controller")) != NULL;) {
 377                 if (!of_device_is_compatible(dn,
 378                                      "IBM,CBEA-Internal-Interrupt-Controller"))
 379                         continue;
 380                 np = of_get_property(dn, "ibm,interrupt-server-ranges", NULL);
 381                 if (np == NULL) {
 382                         printk(KERN_WARNING "IIC: CPU association not found\n");
 383                         of_node_put(dn);
 384                         return -ENODEV;
 385                 }
 386                 if (of_address_to_resource(dn, 0, &r0) ||
 387                     of_address_to_resource(dn, 1, &r1)) {
 388                         printk(KERN_WARNING "IIC: Can't resolve addresses\n");
 389                         of_node_put(dn);
 390                         return -ENODEV;
 391                 }
 392                 found++;
 393                 init_one_iic(np[0], r0.start, dn);
 394                 init_one_iic(np[1], r1.start, dn);
 395
 396                 /* Setup cascade for IO exceptions. XXX cleanup tricks to get
 397                  * node vs CPU etc...
 398                  * Note that we configure the IIC_IRR here with a hard coded
 399                  * priority of 1. We might want to improve that later.
 400                  */
 401                 node = np[0] >> 1;
 402                 node_iic = cbe_get_cpu_iic_regs(np[0]);
 403                 cascade = node << IIC_IRQ_NODE_SHIFT;
 404                 cascade |= 1 << IIC_IRQ_CLASS_SHIFT;
 405                 cascade |= IIC_UNIT_IIC;
 406                 cascade = irq_create_mapping(iic_host, cascade);
 407                 if (cascade == NO_IRQ)
 408                         continue;
 409                 /*
 410                  * irq_data is a generic pointer that gets passed back
 411                  * to us later, so the forced cast is fine.
 412                  */
 413                 set_irq_data(cascade, (void __force *)node_iic);
 414                 set_irq_chained_handler(cascade , iic_ioexc_cascade);
 415                 out_be64(&node_iic->iic_ir,
 416                          (1 << 12)              /* priority */ |
 417                          (node << 4)            /* dest node */ |
 418                          IIC_UNIT_THREAD_0      /* route them to thread 0 */);
 419                 /* Flush pending (make sure it triggers if there is
 420                  * anything pending
 421                  */
 422                 out_be64(&node_iic->iic_is, 0xfffffffffffffffful);
 423         }
 424
 425         if (found)
 426                 return 0;
 427         else
 428                 return -ENODEV;
 429 }
 430
 431 void __init iic_init_IRQ(void)
 432 {
 433         /* Setup an irq host data structure */
 434         iic_host = irq_alloc_host(NULL, IRQ_HOST_MAP_LINEAR, IIC_SOURCE_COUNT,
 435                                   &iic_host_ops, IIC_IRQ_INVALID);
 436         BUG_ON(iic_host == NULL);
 437         irq_set_default_host(iic_host);
 438
 439         /* Discover and initialize iics */
 440         if (setup_iic() < 0)
 441                 panic("IIC: Failed to initialize !\n");
 442
 443         /* Set master interrupt handling function */
 444         ppc_md.get_irq = iic_get_irq;
 445
 446         /* Enable on current CPU */
 447         iic_setup_cpu();
 448 }
 449
 450 void iic_set_interrupt_routing(int cpu, int thread, int priority)
 451 {
 452         struct cbe_iic_regs __iomem *iic_regs = cbe_get_cpu_iic_regs(cpu);
 453         u64 iic_ir = 0;
 454         int node = cpu >> 1;
 455
 456         /* Set which node and thread will handle the next interrupt */
 457         iic_ir |= CBE_IIC_IR_PRIO(priority) |
 458                   CBE_IIC_IR_DEST_NODE(node);
 459         if (thread == 0)
 460                 iic_ir |= CBE_IIC_IR_DEST_UNIT(CBE_IIC_IR_PT_0);
 461         else
 462                 iic_ir |= CBE_IIC_IR_DEST_UNIT(CBE_IIC_IR_PT_1);
 463         out_be64(&iic_regs->iic_ir, iic_ir);
 464 }