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