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/export.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_domain *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 = this_cpu_ptr(&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(struct irq_desc *desc)
 103 {
 104         struct irq_chip *chip = irq_desc_get_chip(desc);
 105         struct cbe_iic_regs __iomem *node_iic =
 106                 (void __iomem *)irq_desc_get_handler_data(desc);
 107         unsigned int irq = irq_desc_get_irq(desc);
 108         unsigned int base = (irq & 0xffffff00) | IIC_IRQ_TYPE_IOEXC;
 109         unsigned long bits, ack;
 110         int cascade;
 111
 112         for (;;) {
 113                 bits = in_be64(&node_iic->iic_is);
 114                 if (bits == 0)
 115                         break;
 116                 /* pre-ack edge interrupts */
 117                 ack = bits & IIC_ISR_EDGE_MASK;
 118                 if (ack)
 119                         out_be64(&node_iic->iic_is, ack);
 120                 /* handle them */
 121                 for (cascade = 63; cascade >= 0; cascade--)
 122                         if (bits & (0x8000000000000000UL >> cascade)) {
 123                                 unsigned int cirq =
 124                                         irq_linear_revmap(iic_host,
 125                                                           base | cascade);
 126                                 if (cirq)
 127                                         generic_handle_irq(cirq);
 128                         }
 129                 /* post-ack level interrupts */
 130                 ack = bits & ~IIC_ISR_EDGE_MASK;
 131                 if (ack)
 132                         out_be64(&node_iic->iic_is, ack);
 133         }
 134         chip->irq_eoi(&desc->irq_data);
 135 }
 136
 137
 138 static struct irq_chip iic_ioexc_chip = {
 139         .name = "CELL-IOEX",
 140         .irq_mask = iic_mask,
 141         .irq_unmask = iic_unmask,
 142         .irq_eoi = iic_ioexc_eoi,
 143 };
 144
 145 /* Get an IRQ number from the pending state register of the IIC */
 146 static unsigned int iic_get_irq(void)
 147 {
 148         struct cbe_iic_pending_bits pending;
 149         struct iic *iic;
 150         unsigned int virq;
 151
 152         iic = this_cpu_ptr(&cpu_iic);
 153         *(unsigned long *) &pending =
 154                 in_be64((u64 __iomem *) &iic->regs->pending_destr);
 155         if (!(pending.flags & CBE_IIC_IRQ_VALID))
 156                 return 0;
 157         virq = irq_linear_revmap(iic_host, iic_pending_to_hwnum(pending));
 158         if (!virq)
 159                 return 0;
 160         iic->eoi_stack[++iic->eoi_ptr] = pending.prio;
 161         BUG_ON(iic->eoi_ptr > 15);
 162         return virq;
 163 }
 164
 165 void iic_setup_cpu(void)
 166 {
 167         out_be64(&this_cpu_ptr(&cpu_iic)->regs->prio, 0xff);
 168 }
 169
 170 u8 iic_get_target_id(int cpu)
 171 {
 172         return per_cpu(cpu_iic, cpu).target_id;
 173 }
 174
 175 EXPORT_SYMBOL_GPL(iic_get_target_id);
 176
 177 #ifdef CONFIG_SMP
 178
 179 /* Use the highest interrupt priorities for IPI */
 180 static inline int iic_msg_to_irq(int msg)
 181 {
 182         return IIC_IRQ_TYPE_IPI + 0xf - msg;
 183 }
 184
 185 void iic_message_pass(int cpu, int msg)
 186 {
 187         out_be64(&per_cpu(cpu_iic, cpu).regs->generate, (0xf - msg) << 4);
 188 }
 189
 190 static void iic_request_ipi(int msg)
 191 {
 192         int virq;
 193
 194         virq = irq_create_mapping(iic_host, iic_msg_to_irq(msg));
 195         if (!virq) {
 196                 printk(KERN_ERR
 197                        "iic: failed to map IPI %s\n", smp_ipi_name[msg]);
 198                 return;
 199         }
 200
 201         /*
 202          * If smp_request_message_ipi encounters an error it will notify
 203          * the error.  If a message is not needed it will return non-zero.
 204          */
 205         if (smp_request_message_ipi(virq, msg))
 206                 irq_dispose_mapping(virq);
 207 }
 208
 209 void iic_request_IPIs(void)
 210 {
 211         iic_request_ipi(PPC_MSG_CALL_FUNCTION);
 212         iic_request_ipi(PPC_MSG_RESCHEDULE);
 213         iic_request_ipi(PPC_MSG_TICK_BROADCAST);
 214         iic_request_ipi(PPC_MSG_DEBUGGER_BREAK);
 215 }
 216
 217 #endif /* CONFIG_SMP */
 218
 219
 220 static int iic_host_match(struct irq_domain *h, struct device_node *node,
 221                           enum irq_domain_bus_token bus_token)
 222 {
 223         return of_device_is_compatible(node,
 224                                     "IBM,CBEA-Internal-Interrupt-Controller");
 225 }
 226
 227 static int iic_host_map(struct irq_domain *h, unsigned int virq,
 228                         irq_hw_number_t hw)
 229 {
 230         switch (hw & IIC_IRQ_TYPE_MASK) {
 231         case IIC_IRQ_TYPE_IPI:
 232                 irq_set_chip_and_handler(virq, &iic_chip, handle_percpu_irq);
 233                 break;
 234         case IIC_IRQ_TYPE_IOEXC:
 235                 irq_set_chip_and_handler(virq, &iic_ioexc_chip,
 236                                          handle_edge_eoi_irq);
 237                 break;
 238         default:
 239                 irq_set_chip_and_handler(virq, &iic_chip, handle_edge_eoi_irq);
 240         }
 241         return 0;
 242 }
 243
 244 static int iic_host_xlate(struct irq_domain *h, struct device_node *ct,
 245                            const u32 *intspec, unsigned int intsize,
 246                            irq_hw_number_t *out_hwirq, unsigned int *out_flags)
 247
 248 {
 249         unsigned int node, ext, unit, class;
 250         const u32 *val;
 251
 252         if (!of_device_is_compatible(ct,
 253                                      "IBM,CBEA-Internal-Interrupt-Controller"))
 254                 return -ENODEV;
 255         if (intsize != 1)
 256                 return -ENODEV;
 257         val = of_get_property(ct, "#interrupt-cells", NULL);
 258         if (val == NULL || *val != 1)
 259                 return -ENODEV;
 260
 261         node = intspec[0] >> 24;
 262         ext = (intspec[0] >> 16) & 0xff;
 263         class = (intspec[0] >> 8) & 0xff;
 264         unit = intspec[0] & 0xff;
 265
 266         /* Check if node is in supported range */
 267         if (node > 1)
 268                 return -EINVAL;
 269
 270         /* Build up interrupt number, special case for IO exceptions */
 271         *out_hwirq = (node << IIC_IRQ_NODE_SHIFT);
 272         if (unit == IIC_UNIT_IIC && class == 1)
 273                 *out_hwirq |= IIC_IRQ_TYPE_IOEXC | ext;
 274         else
 275                 *out_hwirq |= IIC_IRQ_TYPE_NORMAL |
 276                         (class << IIC_IRQ_CLASS_SHIFT) | unit;
 277
 278         /* Dummy flags, ignored by iic code */
 279         *out_flags = IRQ_TYPE_EDGE_RISING;
 280
 281         return 0;
 282 }
 283
 284 static const struct irq_domain_ops iic_host_ops = {
 285         .match = iic_host_match,
 286         .map = iic_host_map,
 287         .xlate = iic_host_xlate,
 288 };
 289
 290 static void __init init_one_iic(unsigned int hw_cpu, unsigned long addr,
 291                                 struct device_node *node)
 292 {
 293         /* XXX FIXME: should locate the linux CPU number from the HW cpu
 294          * number properly. We are lucky for now
 295          */
 296         struct iic *iic = &per_cpu(cpu_iic, hw_cpu);
 297
 298         iic->regs = ioremap(addr, sizeof(struct cbe_iic_thread_regs));
 299         BUG_ON(iic->regs == NULL);
 300
 301         iic->target_id = ((hw_cpu & 2) << 3) | ((hw_cpu & 1) ? 0xf : 0xe);
 302         iic->eoi_stack[0] = 0xff;
 303         iic->node = of_node_get(node);
 304         out_be64(&iic->regs->prio, 0);
 305
 306         printk(KERN_INFO "IIC for CPU %d target id 0x%x : %s\n",
 307                hw_cpu, iic->target_id, node->full_name);
 308 }
 309
 310 static int __init setup_iic(void)
 311 {
 312         struct device_node *dn;
 313         struct resource r0, r1;
 314         unsigned int node, cascade, found = 0;
 315         struct cbe_iic_regs __iomem *node_iic;
 316         const u32 *np;
 317
 318         for (dn = NULL;
 319              (dn = of_find_node_by_name(dn,"interrupt-controller")) != NULL;) {
 320                 if (!of_device_is_compatible(dn,
 321                                      "IBM,CBEA-Internal-Interrupt-Controller"))
 322                         continue;
 323                 np = of_get_property(dn, "ibm,interrupt-server-ranges", NULL);
 324                 if (np == NULL) {
 325                         printk(KERN_WARNING "IIC: CPU association not found\n");
 326                         of_node_put(dn);
 327                         return -ENODEV;
 328                 }
 329                 if (of_address_to_resource(dn, 0, &r0) ||
 330                     of_address_to_resource(dn, 1, &r1)) {
 331                         printk(KERN_WARNING "IIC: Can't resolve addresses\n");
 332                         of_node_put(dn);
 333                         return -ENODEV;
 334                 }
 335                 found++;
 336                 init_one_iic(np[0], r0.start, dn);
 337                 init_one_iic(np[1], r1.start, dn);
 338
 339                 /* Setup cascade for IO exceptions. XXX cleanup tricks to get
 340                  * node vs CPU etc...
 341                  * Note that we configure the IIC_IRR here with a hard coded
 342                  * priority of 1. We might want to improve that later.
 343                  */
 344                 node = np[0] >> 1;
 345                 node_iic = cbe_get_cpu_iic_regs(np[0]);
 346                 cascade = node << IIC_IRQ_NODE_SHIFT;
 347                 cascade |= 1 << IIC_IRQ_CLASS_SHIFT;
 348                 cascade |= IIC_UNIT_IIC;
 349                 cascade = irq_create_mapping(iic_host, cascade);
 350                 if (!cascade)
 351                         continue;
 352                 /*
 353                  * irq_data is a generic pointer that gets passed back
 354                  * to us later, so the forced cast is fine.
 355                  */
 356                 irq_set_handler_data(cascade, (void __force *)node_iic);
 357                 irq_set_chained_handler(cascade, iic_ioexc_cascade);
 358                 out_be64(&node_iic->iic_ir,
 359                          (1 << 12)              /* priority */ |
 360                          (node << 4)            /* dest node */ |
 361                          IIC_UNIT_THREAD_0      /* route them to thread 0 */);
 362                 /* Flush pending (make sure it triggers if there is
 363                  * anything pending
 364                  */
 365                 out_be64(&node_iic->iic_is, 0xfffffffffffffffful);
 366         }
 367
 368         if (found)
 369                 return 0;
 370         else
 371                 return -ENODEV;
 372 }
 373
 374 void __init iic_init_IRQ(void)
 375 {
 376         /* Setup an irq host data structure */
 377         iic_host = irq_domain_add_linear(NULL, IIC_SOURCE_COUNT, &iic_host_ops,
 378                                          NULL);
 379         BUG_ON(iic_host == NULL);
 380         irq_set_default_host(iic_host);
 381
 382         /* Discover and initialize iics */
 383         if (setup_iic() < 0)
 384                 panic("IIC: Failed to initialize !\n");
 385
 386         /* Set master interrupt handling function */
 387         ppc_md.get_irq = iic_get_irq;
 388
 389         /* Enable on current CPU */
 390         iic_setup_cpu();
 391 }
 392
 393 void iic_set_interrupt_routing(int cpu, int thread, int priority)
 394 {
 395         struct cbe_iic_regs __iomem *iic_regs = cbe_get_cpu_iic_regs(cpu);
 396         u64 iic_ir = 0;
 397         int node = cpu >> 1;
 398
 399         /* Set which node and thread will handle the next interrupt */
 400         iic_ir |= CBE_IIC_IR_PRIO(priority) |
 401                   CBE_IIC_IR_DEST_NODE(node);
 402         if (thread == 0)
 403                 iic_ir |= CBE_IIC_IR_DEST_UNIT(CBE_IIC_IR_PT_0);
 404         else
 405                 iic_ir |= CBE_IIC_IR_DEST_UNIT(CBE_IIC_IR_PT_1);
 406         out_be64(&iic_regs->iic_ir, iic_ir);
 407 }