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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/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 #define REAL_IRQ_TO_SUBBUS(irq) (((irq) >> 14) & 0xff)
 166 #define REAL_IRQ_TO_BUS(irq)    ((((irq) >> 6) & 0xff) + 1)
 167 #define REAL_IRQ_TO_IDSEL(irq)  ((((irq) >> 3) & 7) + 1)
 168 #define REAL_IRQ_TO_FUNC(irq)   ((irq) & 7)
 169
 170 /*
 171  * This will be called by device drivers (via enable_IRQ)
 172  * to enable INTA in the bridge interrupt status register.
 173  */
 174 static void iseries_enable_IRQ(unsigned int irq)
 175 {
 176         u32 bus, dev_id, function, mask;
 177         const u32 sub_bus = 0;
 178         unsigned int rirq = (unsigned int)irq_map[irq].hwirq;
 179
 180         /* The IRQ has already been locked by the caller */
 181         bus = REAL_IRQ_TO_BUS(rirq);
 182         function = REAL_IRQ_TO_FUNC(rirq);
 183         dev_id = (REAL_IRQ_TO_IDSEL(rirq) << 4) + function;
 184
 185         /* Unmask secondary INTA */
 186         mask = 0x80000000;
 187         HvCallPci_unmaskInterrupts(bus, sub_bus, dev_id, mask);
 188 }
 189
 190 /* This is called by iseries_activate_IRQs */
 191 static unsigned int iseries_startup_IRQ(unsigned int irq)
 192 {
 193         u32 bus, dev_id, function, mask;
 194         const u32 sub_bus = 0;
 195         unsigned int rirq = (unsigned int)irq_map[irq].hwirq;
 196
 197         bus = REAL_IRQ_TO_BUS(rirq);
 198         function = REAL_IRQ_TO_FUNC(rirq);
 199         dev_id = (REAL_IRQ_TO_IDSEL(rirq) << 4) + function;
 200
 201         /* Link the IRQ number to the bridge */
 202         HvCallXm_connectBusUnit(bus, sub_bus, dev_id, irq);
 203
 204         /* Unmask bridge interrupts in the FISR */
 205         mask = 0x01010000 << function;
 206         HvCallPci_unmaskFisr(bus, sub_bus, dev_id, mask);
 207         iseries_enable_IRQ(irq);
 208         return 0;
 209 }
 210
 211 /*
 212  * This is called out of iSeries_fixup to activate interrupt
 213  * generation for usable slots
 214  */
 215 void __init iSeries_activate_IRQs()
 216 {
 217         int irq;
 218         unsigned long flags;
 219
 220         for_each_irq (irq) {
 221                 irq_desc_t *desc = get_irq_desc(irq);
 222
 223                 if (desc && desc->chip && desc->chip->startup) {
 224                         spin_lock_irqsave(&desc->lock, flags);
 225                         desc->chip->startup(irq);
 226                         spin_unlock_irqrestore(&desc->lock, flags);
 227                 }
 228         }
 229 }
 230
 231 /*  this is not called anywhere currently */
 232 static void iseries_shutdown_IRQ(unsigned int irq)
 233 {
 234         u32 bus, dev_id, function, mask;
 235         const u32 sub_bus = 0;
 236         unsigned int rirq = (unsigned int)irq_map[irq].hwirq;
 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(unsigned int irq)
 256 {
 257         u32 bus, dev_id, function, mask;
 258         const u32 sub_bus = 0;
 259         unsigned int rirq = (unsigned int)irq_map[irq].hwirq;
 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(unsigned int irq)
 272 {
 273         unsigned int rirq = (unsigned int)irq_map[irq].hwirq;
 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         .typename       = "iSeries irq controller",
 281         .startup        = iseries_startup_IRQ,
 282         .shutdown       = iseries_shutdown_IRQ,
 283         .unmask         = iseries_enable_IRQ,
 284         .mask           = iseries_disable_IRQ,
 285         .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(struct pt_regs *regs)
 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                 iSeries_smp_message_recv(regs);
 319         }
 320 #endif /* CONFIG_SMP */
 321         if (hvlpevent_is_pending())
 322                 process_hvlpevents(regs);
 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 static int iseries_irq_host_map(struct irq_host *h, unsigned int virq,
 344                                 irq_hw_number_t hw)
 345 {
 346         set_irq_chip_and_handler(virq, &iseries_pic, handle_fasteoi_irq);
 347
 348         return 0;
 349 }
 350
 351 static struct irq_host_ops iseries_irq_host_ops = {
 352         .map = iseries_irq_host_map,
 353 };
 354
 355 /*
 356  * This is called by init_IRQ.  set in ppc_md.init_IRQ by iSeries_setup.c
 357  * It must be called before the bus walk.
 358  */
 359 void __init iSeries_init_IRQ(void)
 360 {
 361         /* Register PCI event handler and open an event path */
 362         struct irq_host *host;
 363         int ret;
 364
 365         /*
 366          * The Hypervisor only allows us up to 256 interrupt
 367          * sources (the irq number is passed in a u8).
 368          */
 369         irq_set_virq_count(256);
 370
 371         /* Create irq host. No need for a revmap since HV will give us
 372          * back our virtual irq number
 373          */
 374         host = irq_alloc_host(IRQ_HOST_MAP_NOMAP, 0, &iseries_irq_host_ops, 0);
 375         BUG_ON(host == NULL);
 376         irq_set_default_host(host);
 377
 378         ret = HvLpEvent_registerHandler(HvLpEvent_Type_PciIo,
 379                         &pci_event_handler);
 380         if (ret == 0) {
 381                 ret = HvLpEvent_openPath(HvLpEvent_Type_PciIo, 0);
 382                 if (ret != 0)
 383                         printk(KERN_ERR "iseries_init_IRQ: open event path "
 384                                         "failed with rc 0x%x\n", ret);
 385         } else
 386                 printk(KERN_ERR "iseries_init_IRQ: register handler "
 387                                 "failed with rc 0x%x\n", ret);
 388 }
 389