linux/arch/powerpc/platforms/iseries/irq.c
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   1/*
   2 * This module supports the iSeries PCI bus interrupt handling
   3 * Copyright (C) 20yy  <Robert L Holtorf> <IBM Corp>
   4 * Copyright (C) 2004-2005 IBM Corporation
   5 *
   6 * This program is free software; you can redistribute it and/or modify
   7 * it under the terms of the GNU General Public License as published by
   8 * the Free Software Foundation; either version 2 of the License, or
   9 * (at your option) any later version.
  10 *
  11 * This program is distributed in the hope that it will be useful,
  12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 * GNU General Public License for more details.
  15 *
  16 * You should have received a copy of the GNU General Public License
  17 * along with this program; if not, write to the:
  18 * Free Software Foundation, Inc.,
  19 * 59 Temple Place, Suite 330,
  20 * Boston, MA  02111-1307  USA
  21 *
  22 * Change Activity:
  23 *   Created, December 13, 2000 by Wayne Holm
  24 * End Change Activity
  25 */
  26#include <linux/pci.h>
  27#include <linux/init.h>
  28#include <linux/threads.h>
  29#include <linux/smp.h>
  30#include <linux/param.h>
  31#include <linux/string.h>
  32#include <linux/bootmem.h>
  33#include <linux/irq.h>
  34#include <linux/spinlock.h>
  35
  36#include <asm/paca.h>
  37#include <asm/iseries/hv_types.h>
  38#include <asm/iseries/hv_lp_event.h>
  39#include <asm/iseries/hv_call_xm.h>
  40#include <asm/iseries/it_lp_queue.h>
  41
  42#include "irq.h"
  43#include "pci.h"
  44#include "call_pci.h"
  45
  46#ifdef CONFIG_PCI
  47
  48enum pci_event_type {
  49        pe_bus_created          = 0,    /* PHB has been created */
  50        pe_bus_error            = 1,    /* PHB has failed */
  51        pe_bus_failed           = 2,    /* Msg to Secondary, Primary failed bus */
  52        pe_node_failed          = 4,    /* Multi-adapter bridge has failed */
  53        pe_node_recovered       = 5,    /* Multi-adapter bridge has recovered */
  54        pe_bus_recovered        = 12,   /* PHB has been recovered */
  55        pe_unquiese_bus         = 18,   /* Secondary bus unqiescing */
  56        pe_bridge_error         = 21,   /* Bridge Error */
  57        pe_slot_interrupt       = 22    /* Slot interrupt */
  58};
  59
  60struct pci_event {
  61        struct HvLpEvent event;
  62        union {
  63                u64 __align;            /* Align on an 8-byte boundary */
  64                struct {
  65                        u32             fisr;
  66                        HvBusNumber     bus_number;
  67                        HvSubBusNumber  sub_bus_number;
  68                        HvAgentId       dev_id;
  69                } slot;
  70                struct {
  71                        HvBusNumber     bus_number;
  72                        HvSubBusNumber  sub_bus_number;
  73                } bus;
  74                struct {
  75                        HvBusNumber     bus_number;
  76                        HvSubBusNumber  sub_bus_number;
  77                        HvAgentId       dev_id;
  78                } node;
  79        } data;
  80};
  81
  82static DEFINE_SPINLOCK(pending_irqs_lock);
  83static int num_pending_irqs;
  84static int pending_irqs[NR_IRQS];
  85
  86static void int_received(struct pci_event *event)
  87{
  88        int irq;
  89
  90        switch (event->event.xSubtype) {
  91        case pe_slot_interrupt:
  92                irq = event->event.xCorrelationToken;
  93                if (irq < NR_IRQS) {
  94                        spin_lock(&pending_irqs_lock);
  95                        pending_irqs[irq]++;
  96                        num_pending_irqs++;
  97                        spin_unlock(&pending_irqs_lock);
  98                } else {
  99                        printk(KERN_WARNING "int_received: bad irq number %d\n",
 100                                        irq);
 101                        HvCallPci_eoi(event->data.slot.bus_number,
 102                                        event->data.slot.sub_bus_number,
 103                                        event->data.slot.dev_id);
 104                }
 105                break;
 106                /* Ignore error recovery events for now */
 107        case pe_bus_created:
 108                printk(KERN_INFO "int_received: system bus %d created\n",
 109                        event->data.bus.bus_number);
 110                break;
 111        case pe_bus_error:
 112        case pe_bus_failed:
 113                printk(KERN_INFO "int_received: system bus %d failed\n",
 114                        event->data.bus.bus_number);
 115                break;
 116        case pe_bus_recovered:
 117        case pe_unquiese_bus:
 118                printk(KERN_INFO "int_received: system bus %d recovered\n",
 119                        event->data.bus.bus_number);
 120                break;
 121        case pe_node_failed:
 122        case pe_bridge_error:
 123                printk(KERN_INFO
 124                        "int_received: multi-adapter bridge %d/%d/%d failed\n",
 125                        event->data.node.bus_number,
 126                        event->data.node.sub_bus_number,
 127                        event->data.node.dev_id);
 128                break;
 129        case pe_node_recovered:
 130                printk(KERN_INFO
 131                        "int_received: multi-adapter bridge %d/%d/%d recovered\n",
 132                        event->data.node.bus_number,
 133                        event->data.node.sub_bus_number,
 134                        event->data.node.dev_id);
 135                break;
 136        default:
 137                printk(KERN_ERR
 138                        "int_received: unrecognized event subtype 0x%x\n",
 139                        event->event.xSubtype);
 140                break;
 141        }
 142}
 143
 144static void pci_event_handler(struct HvLpEvent *event)
 145{
 146        if (event && (event->xType == HvLpEvent_Type_PciIo)) {
 147                if (hvlpevent_is_int(event))
 148                        int_received((struct pci_event *)event);
 149                else
 150                        printk(KERN_ERR
 151                                "pci_event_handler: unexpected ack received\n");
 152        } else if (event)
 153                printk(KERN_ERR
 154                        "pci_event_handler: Unrecognized PCI event type 0x%x\n",
 155                        (int)event->xType);
 156        else
 157                printk(KERN_ERR "pci_event_handler: NULL event received\n");
 158}
 159
 160#define REAL_IRQ_TO_SUBBUS(irq) (((irq) >> 14) & 0xff)
 161#define REAL_IRQ_TO_BUS(irq)    ((((irq) >> 6) & 0xff) + 1)
 162#define REAL_IRQ_TO_IDSEL(irq)  ((((irq) >> 3) & 7) + 1)
 163#define REAL_IRQ_TO_FUNC(irq)   ((irq) & 7)
 164
 165/*
 166 * This will be called by device drivers (via enable_IRQ)
 167 * to enable INTA in the bridge interrupt status register.
 168 */
 169static void iseries_enable_IRQ(struct irq_data *d)
 170{
 171        u32 bus, dev_id, function, mask;
 172        const u32 sub_bus = 0;
 173        unsigned int rirq = (unsigned int)irqd_to_hwirq(d);
 174
 175        /* The IRQ has already been locked by the caller */
 176        bus = REAL_IRQ_TO_BUS(rirq);
 177        function = REAL_IRQ_TO_FUNC(rirq);
 178        dev_id = (REAL_IRQ_TO_IDSEL(rirq) << 4) + function;
 179
 180        /* Unmask secondary INTA */
 181        mask = 0x80000000;
 182        HvCallPci_unmaskInterrupts(bus, sub_bus, dev_id, mask);
 183}
 184
 185/* This is called by iseries_activate_IRQs */
 186static unsigned int iseries_startup_IRQ(struct irq_data *d)
 187{
 188        u32 bus, dev_id, function, mask;
 189        const u32 sub_bus = 0;
 190        unsigned int rirq = (unsigned int)irqd_to_hwirq(d);
 191
 192        bus = REAL_IRQ_TO_BUS(rirq);
 193        function = REAL_IRQ_TO_FUNC(rirq);
 194        dev_id = (REAL_IRQ_TO_IDSEL(rirq) << 4) + function;
 195
 196        /* Link the IRQ number to the bridge */
 197        HvCallXm_connectBusUnit(bus, sub_bus, dev_id, d->irq);
 198
 199        /* Unmask bridge interrupts in the FISR */
 200        mask = 0x01010000 << function;
 201        HvCallPci_unmaskFisr(bus, sub_bus, dev_id, mask);
 202        iseries_enable_IRQ(d);
 203        return 0;
 204}
 205
 206/*
 207 * This is called out of iSeries_fixup to activate interrupt
 208 * generation for usable slots
 209 */
 210void __init iSeries_activate_IRQs()
 211{
 212        int irq;
 213        unsigned long flags;
 214
 215        for_each_irq (irq) {
 216                struct irq_desc *desc = irq_to_desc(irq);
 217                struct irq_chip *chip;
 218
 219                if (!desc)
 220                        continue;
 221
 222                chip = irq_desc_get_chip(desc);
 223                if (chip && chip->irq_startup) {
 224                        raw_spin_lock_irqsave(&desc->lock, flags);
 225                        chip->irq_startup(&desc->irq_data);
 226                        raw_spin_unlock_irqrestore(&desc->lock, flags);
 227                }
 228        }
 229}
 230
 231/*  this is not called anywhere currently */
 232static void iseries_shutdown_IRQ(struct irq_data *d)
 233{
 234        u32 bus, dev_id, function, mask;
 235        const u32 sub_bus = 0;
 236        unsigned int rirq = (unsigned int)irqd_to_hwirq(d);
 237
 238        /* irq should be locked by the caller */
 239        bus = REAL_IRQ_TO_BUS(rirq);
 240        function = REAL_IRQ_TO_FUNC(rirq);
 241        dev_id = (REAL_IRQ_TO_IDSEL(rirq) << 4) + function;
 242
 243        /* Invalidate the IRQ number in the bridge */
 244        HvCallXm_connectBusUnit(bus, sub_bus, dev_id, 0);
 245
 246        /* Mask bridge interrupts in the FISR */
 247        mask = 0x01010000 << function;
 248        HvCallPci_maskFisr(bus, sub_bus, dev_id, mask);
 249}
 250
 251/*
 252 * This will be called by device drivers (via disable_IRQ)
 253 * to disable INTA in the bridge interrupt status register.
 254 */
 255static void iseries_disable_IRQ(struct irq_data *d)
 256{
 257        u32 bus, dev_id, function, mask;
 258        const u32 sub_bus = 0;
 259        unsigned int rirq = (unsigned int)irqd_to_hwirq(d);
 260
 261        /* The IRQ has already been locked by the caller */
 262        bus = REAL_IRQ_TO_BUS(rirq);
 263        function = REAL_IRQ_TO_FUNC(rirq);
 264        dev_id = (REAL_IRQ_TO_IDSEL(rirq) << 4) + function;
 265
 266        /* Mask secondary INTA   */
 267        mask = 0x80000000;
 268        HvCallPci_maskInterrupts(bus, sub_bus, dev_id, mask);
 269}
 270
 271static void iseries_end_IRQ(struct irq_data *d)
 272{
 273        unsigned int rirq = (unsigned int)irqd_to_hwirq(d);
 274
 275        HvCallPci_eoi(REAL_IRQ_TO_BUS(rirq), REAL_IRQ_TO_SUBBUS(rirq),
 276                (REAL_IRQ_TO_IDSEL(rirq) << 4) + REAL_IRQ_TO_FUNC(rirq));
 277}
 278
 279static struct irq_chip iseries_pic = {
 280        .name           = "iSeries",
 281        .irq_startup    = iseries_startup_IRQ,
 282        .irq_shutdown   = iseries_shutdown_IRQ,
 283        .irq_unmask     = iseries_enable_IRQ,
 284        .irq_mask       = iseries_disable_IRQ,
 285        .irq_eoi        = iseries_end_IRQ
 286};
 287
 288/*
 289 * This is called out of iSeries_scan_slot to allocate an IRQ for an EADS slot
 290 * It calculates the irq value for the slot.
 291 * Note that sub_bus is always 0 (at the moment at least).
 292 */
 293int __init iSeries_allocate_IRQ(HvBusNumber bus,
 294                HvSubBusNumber sub_bus, u32 bsubbus)
 295{
 296        unsigned int realirq;
 297        u8 idsel = ISERIES_GET_DEVICE_FROM_SUBBUS(bsubbus);
 298        u8 function = ISERIES_GET_FUNCTION_FROM_SUBBUS(bsubbus);
 299
 300        realirq = (((((sub_bus << 8) + (bus - 1)) << 3) + (idsel - 1)) << 3)
 301                + function;
 302
 303        return irq_create_mapping(NULL, realirq);
 304}
 305
 306#endif /* CONFIG_PCI */
 307
 308/*
 309 * Get the next pending IRQ.
 310 */
 311unsigned int iSeries_get_irq(void)
 312{
 313        int irq = NO_IRQ_IGNORE;
 314
 315#ifdef CONFIG_SMP
 316        if (get_lppaca()->int_dword.fields.ipi_cnt) {
 317                get_lppaca()->int_dword.fields.ipi_cnt = 0;
 318                smp_ipi_demux();
 319        }
 320#endif /* CONFIG_SMP */
 321        if (hvlpevent_is_pending())
 322                process_hvlpevents();
 323
 324#ifdef CONFIG_PCI
 325        if (num_pending_irqs) {
 326                spin_lock(&pending_irqs_lock);
 327                for (irq = 0; irq < NR_IRQS; irq++) {
 328                        if (pending_irqs[irq]) {
 329                                pending_irqs[irq]--;
 330                                num_pending_irqs--;
 331                                break;
 332                        }
 333                }
 334                spin_unlock(&pending_irqs_lock);
 335                if (irq >= NR_IRQS)
 336                        irq = NO_IRQ_IGNORE;
 337        }
 338#endif
 339
 340        return irq;
 341}
 342
 343#ifdef CONFIG_PCI
 344
 345static int iseries_irq_host_map(struct irq_host *h, unsigned int virq,
 346                                irq_hw_number_t hw)
 347{
 348        irq_set_chip_and_handler(virq, &iseries_pic, handle_fasteoi_irq);
 349
 350        return 0;
 351}
 352
 353static int iseries_irq_host_match(struct irq_host *h, struct device_node *np)
 354{
 355        /* Match all */
 356        return 1;
 357}
 358
 359static struct irq_host_ops iseries_irq_host_ops = {
 360        .map = iseries_irq_host_map,
 361        .match = iseries_irq_host_match,
 362};
 363
 364/*
 365 * This is called by init_IRQ.  set in ppc_md.init_IRQ by iSeries_setup.c
 366 * It must be called before the bus walk.
 367 */
 368void __init iSeries_init_IRQ(void)
 369{
 370        /* Register PCI event handler and open an event path */
 371        struct irq_host *host;
 372        int ret;
 373
 374        /*
 375         * The Hypervisor only allows us up to 256 interrupt
 376         * sources (the irq number is passed in a u8).
 377         */
 378        irq_set_virq_count(256);
 379
 380        /* Create irq host. No need for a revmap since HV will give us
 381         * back our virtual irq number
 382         */
 383        host = irq_alloc_host(NULL, IRQ_HOST_MAP_NOMAP, 0,
 384                              &iseries_irq_host_ops, 0);
 385        BUG_ON(host == NULL);
 386        irq_set_default_host(host);
 387
 388        ret = HvLpEvent_registerHandler(HvLpEvent_Type_PciIo,
 389                        &pci_event_handler);
 390        if (ret == 0) {
 391                ret = HvLpEvent_openPath(HvLpEvent_Type_PciIo, 0);
 392                if (ret != 0)
 393                        printk(KERN_ERR "iseries_init_IRQ: open event path "
 394                                        "failed with rc 0x%x\n", ret);
 395        } else
 396                printk(KERN_ERR "iseries_init_IRQ: register handler "
 397                                "failed with rc 0x%x\n", ret);
 398}
 399
 400#endif  /* CONFIG_PCI */
 401