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