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/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
  48 enum 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
  60 struct 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
  82 static DEFINE_SPINLOCK(pending_irqs_lock);
  83 static int num_pending_irqs;
  84 static int pending_irqs[NR_IRQS];
  85
  86 static 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
 144 static 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  */
 169 static 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 */
 186 static 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  */
 210 void __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 */
 232 static 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  */
 255 static 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
 271 static 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
 279 static 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  */
 293 int __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  */
 311 unsigned 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
 345 static 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
 353 static int iseries_irq_host_match(struct irq_host *h, struct device_node *np)
 354 {
 355         /* Match all */
 356         return 1;
 357 }
 358
 359 static 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  */
 368 void __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 */