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
  26 #include <linux/interrupt.h>
  27 #include <linux/irq.h>
  28 #include <linux/module.h>
  29 #include <linux/percpu.h>
  30 #include <linux/types.h>
  31 #include <linux/ioport.h>
  32
  33 #include <asm/io.h>
  34 #include <asm/pgtable.h>
  35 #include <asm/prom.h>
  36 #include <asm/ptrace.h>
  37 #include <asm/machdep.h>
  38
  39 #include "interrupt.h"
  40 #include "cbe_regs.h"
  41
  42 struct iic {
  43         struct cbe_iic_thread_regs __iomem *regs;
  44         u8 target_id;
  45         u8 eoi_stack[16];
  46         int eoi_ptr;
  47         struct irq_host *host;
  48 };
  49
  50 static DEFINE_PER_CPU(struct iic, iic);
  51 #define IIC_NODE_COUNT  2
  52 static struct irq_host *iic_hosts[IIC_NODE_COUNT];
  53
  54 /* Convert between "pending" bits and hw irq number */
  55 static irq_hw_number_t iic_pending_to_hwnum(struct cbe_iic_pending_bits bits)
  56 {
  57         unsigned char unit = bits.source & 0xf;
  58
  59         if (bits.flags & CBE_IIC_IRQ_IPI)
  60                 return IIC_IRQ_IPI0 | (bits.prio >> 4);
  61         else if (bits.class <= 3)
  62                 return (bits.class << 4) | unit;
  63         else
  64                 return IIC_IRQ_INVALID;
  65 }
  66
  67 static void iic_mask(unsigned int irq)
  68 {
  69 }
  70
  71 static void iic_unmask(unsigned int irq)
  72 {
  73 }
  74
  75 static void iic_eoi(unsigned int irq)
  76 {
  77         struct iic *iic = &__get_cpu_var(iic);
  78         out_be64(&iic->regs->prio, iic->eoi_stack[--iic->eoi_ptr]);
  79         BUG_ON(iic->eoi_ptr < 0);
  80 }
  81
  82 static struct irq_chip iic_chip = {
  83         .typename = " CELL-IIC ",
  84         .mask = iic_mask,
  85         .unmask = iic_unmask,
  86         .eoi = iic_eoi,
  87 };
  88
  89 /* Get an IRQ number from the pending state register of the IIC */
  90 static unsigned int iic_get_irq(struct pt_regs *regs)
  91 {
  92         struct cbe_iic_pending_bits pending;
  93         struct iic *iic;
  94
  95         iic = &__get_cpu_var(iic);
  96         *(unsigned long *) &pending =
  97                 in_be64((unsigned long __iomem *) &iic->regs->pending_destr);
  98         iic->eoi_stack[++iic->eoi_ptr] = pending.prio;
  99         BUG_ON(iic->eoi_ptr > 15);
 100         if (pending.flags & CBE_IIC_IRQ_VALID)
 101                 return irq_linear_revmap(iic->host,
 102                                          iic_pending_to_hwnum(pending));
 103         return NO_IRQ;
 104 }
 105
 106 #ifdef CONFIG_SMP
 107
 108 /* Use the highest interrupt priorities for IPI */
 109 static inline int iic_ipi_to_irq(int ipi)
 110 {
 111         return IIC_IRQ_IPI0 + IIC_NUM_IPIS - 1 - ipi;
 112 }
 113
 114 static inline int iic_irq_to_ipi(int irq)
 115 {
 116         return IIC_NUM_IPIS - 1 - (irq - IIC_IRQ_IPI0);
 117 }
 118
 119 void iic_setup_cpu(void)
 120 {
 121         out_be64(&__get_cpu_var(iic).regs->prio, 0xff);
 122 }
 123
 124 void iic_cause_IPI(int cpu, int mesg)
 125 {
 126         out_be64(&per_cpu(iic, cpu).regs->generate, (IIC_NUM_IPIS - 1 - mesg) << 4);
 127 }
 128
 129 u8 iic_get_target_id(int cpu)
 130 {
 131         return per_cpu(iic, cpu).target_id;
 132 }
 133 EXPORT_SYMBOL_GPL(iic_get_target_id);
 134
 135 struct irq_host *iic_get_irq_host(int node)
 136 {
 137         if (node < 0 || node >= IIC_NODE_COUNT)
 138                 return NULL;
 139         return iic_hosts[node];
 140 }
 141 EXPORT_SYMBOL_GPL(iic_get_irq_host);
 142
 143
 144 static irqreturn_t iic_ipi_action(int irq, void *dev_id, struct pt_regs *regs)
 145 {
 146         int ipi = (int)(long)dev_id;
 147
 148         smp_message_recv(ipi, regs);
 149
 150         return IRQ_HANDLED;
 151 }
 152
 153 static void iic_request_ipi(int ipi, const char *name)
 154 {
 155         int node, virq;
 156
 157         for (node = 0; node < IIC_NODE_COUNT; node++) {
 158                 char *rname;
 159                 if (iic_hosts[node] == NULL)
 160                         continue;
 161                 virq = irq_create_mapping(iic_hosts[node],
 162                                           iic_ipi_to_irq(ipi));
 163                 if (virq == NO_IRQ) {
 164                         printk(KERN_ERR
 165                                "iic: failed to map IPI %s on node %d\n",
 166                                name, node);
 167                         continue;
 168                 }
 169                 rname = kzalloc(strlen(name) + 16, GFP_KERNEL);
 170                 if (rname)
 171                         sprintf(rname, "%s node %d", name, node);
 172                 else
 173                         rname = (char *)name;
 174                 if (request_irq(virq, iic_ipi_action, IRQF_DISABLED,
 175                                 rname, (void *)(long)ipi))
 176                         printk(KERN_ERR
 177                                "iic: failed to request IPI %s on node %d\n",
 178                                name, node);
 179         }
 180 }
 181
 182 void iic_request_IPIs(void)
 183 {
 184         iic_request_ipi(PPC_MSG_CALL_FUNCTION, "IPI-call");
 185         iic_request_ipi(PPC_MSG_RESCHEDULE, "IPI-resched");
 186 #ifdef CONFIG_DEBUGGER
 187         iic_request_ipi(PPC_MSG_DEBUGGER_BREAK, "IPI-debug");
 188 #endif /* CONFIG_DEBUGGER */
 189 }
 190
 191 #endif /* CONFIG_SMP */
 192
 193
 194 static int iic_host_match(struct irq_host *h, struct device_node *node)
 195 {
 196         return h->host_data != NULL && node == h->host_data;
 197 }
 198
 199 static int iic_host_map(struct irq_host *h, unsigned int virq,
 200                         irq_hw_number_t hw)
 201 {
 202         if (hw < IIC_IRQ_IPI0)
 203                 set_irq_chip_and_handler(virq, &iic_chip, handle_fasteoi_irq);
 204         else
 205                 set_irq_chip_and_handler(virq, &iic_chip, handle_percpu_irq);
 206         return 0;
 207 }
 208
 209 static int iic_host_xlate(struct irq_host *h, struct device_node *ct,
 210                            u32 *intspec, unsigned int intsize,
 211                            irq_hw_number_t *out_hwirq, unsigned int *out_flags)
 212
 213 {
 214         /* Currently, we don't translate anything. That needs to be fixed as
 215          * we get better defined device-trees. iic interrupts have to be
 216          * explicitely mapped by whoever needs them
 217          */
 218         return -ENODEV;
 219 }
 220
 221 static struct irq_host_ops iic_host_ops = {
 222         .match = iic_host_match,
 223         .map = iic_host_map,
 224         .xlate = iic_host_xlate,
 225 };
 226
 227 static void __init init_one_iic(unsigned int hw_cpu, unsigned long addr,
 228                                 struct irq_host *host)
 229 {
 230         /* XXX FIXME: should locate the linux CPU number from the HW cpu
 231          * number properly. We are lucky for now
 232          */
 233         struct iic *iic = &per_cpu(iic, hw_cpu);
 234
 235         iic->regs = ioremap(addr, sizeof(struct cbe_iic_thread_regs));
 236         BUG_ON(iic->regs == NULL);
 237
 238         iic->target_id = ((hw_cpu & 2) << 3) | ((hw_cpu & 1) ? 0xf : 0xe);
 239         iic->eoi_stack[0] = 0xff;
 240         iic->host = host;
 241         out_be64(&iic->regs->prio, 0);
 242
 243         printk(KERN_INFO "IIC for CPU %d at %lx mapped to %p, target id 0x%x\n",
 244                hw_cpu, addr, iic->regs, iic->target_id);
 245 }
 246
 247 static int __init setup_iic(void)
 248 {
 249         struct device_node *dn;
 250         struct resource r0, r1;
 251         struct irq_host *host;
 252         int found = 0;
 253         const u32 *np;
 254
 255         for (dn = NULL;
 256              (dn = of_find_node_by_name(dn,"interrupt-controller")) != NULL;) {
 257                 if (!device_is_compatible(dn,
 258                                      "IBM,CBEA-Internal-Interrupt-Controller"))
 259                         continue;
 260                 np = get_property(dn, "ibm,interrupt-server-ranges", NULL);
 261                 if (np == NULL) {
 262                         printk(KERN_WARNING "IIC: CPU association not found\n");
 263                         of_node_put(dn);
 264                         return -ENODEV;
 265                 }
 266                 if (of_address_to_resource(dn, 0, &r0) ||
 267                     of_address_to_resource(dn, 1, &r1)) {
 268                         printk(KERN_WARNING "IIC: Can't resolve addresses\n");
 269                         of_node_put(dn);
 270                         return -ENODEV;
 271                 }
 272                 host = NULL;
 273                 if (found < IIC_NODE_COUNT) {
 274                         host = irq_alloc_host(IRQ_HOST_MAP_LINEAR,
 275                                               IIC_SOURCE_COUNT,
 276                                               &iic_host_ops,
 277                                               IIC_IRQ_INVALID);
 278                         iic_hosts[found] = host;
 279                         BUG_ON(iic_hosts[found] == NULL);
 280                         iic_hosts[found]->host_data = of_node_get(dn);
 281                         found++;
 282                 }
 283                 init_one_iic(np[0], r0.start, host);
 284                 init_one_iic(np[1], r1.start, host);
 285         }
 286
 287         if (found)
 288                 return 0;
 289         else
 290                 return -ENODEV;
 291 }
 292
 293 void __init iic_init_IRQ(void)
 294 {
 295         /* Discover and initialize iics */
 296         if (setup_iic() < 0)
 297                 panic("IIC: Failed to initialize !\n");
 298
 299         /* Set master interrupt handling function */
 300         ppc_md.get_irq = iic_get_irq;
 301
 302         /* Enable on current CPU */
 303         iic_setup_cpu();
 304 }