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