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