arch/powerpc/platforms/iseries/irq.c

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