arch/ppc64/kernel/iSeries_irq.c

   1 /************************************************************************/
   2 /* This module supports the iSeries PCI bus interrupt handling          */
   3 /* Copyright (C) 20yy  <Robert L Holtorf> <IBM Corp>                    */
   4 /*                                                                      */
   5 /* This program is free software; you can redistribute it and/or modify */
   6 /* it under the terms of the GNU General Public License as published by */
   7 /* the Free Software Foundation; either version 2 of the License, or    */
   8 /* (at your option) any later version.                                  */
   9 /*                                                                      */
  10 /* This program is distributed in the hope that it will be useful,      */
  11 /* but WITHOUT ANY WARRANTY; without even the implied warranty of       */
  12 /* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the        */
  13 /* GNU General Public License for more details.                         */
  14 /*                                                                      */
  15 /* You should have received a copy of the GNU General Public License    */
  16 /* along with this program; if not, write to the:                       */
  17 /* Free Software Foundation, Inc.,                                      */
  18 /* 59 Temple Place, Suite 330,                                          */
  19 /* Boston, MA  02111-1307  USA                                          */
  20 /************************************************************************/
  21 /* Change Activity:                                                     */
  22 /*   Created, December 13, 2000 by Wayne Holm                           */
  23 /* End Change Activity                                                  */
  24 /************************************************************************/
  25 #include <linux/pci.h>
  26 #include <linux/init.h>
  27 #include <linux/threads.h>
  28 #include <linux/smp.h>
  29 #include <linux/param.h>
  30 #include <linux/string.h>
  31 #include <linux/bootmem.h>
  32 #include <linux/ide.h>
  33
  34 #include <linux/irq.h>
  35 #include <linux/spinlock.h>
  36 #include <asm/ppcdebug.h>
  37
  38 #include <asm/iSeries/HvCallPci.h>
  39 #include <asm/iSeries/HvCallXm.h>
  40 #include <asm/iSeries/iSeries_irq.h>
  41 #include <asm/iSeries/XmPciLpEvent.h>
  42
  43 static unsigned int iSeries_startup_IRQ(unsigned int irq);
  44 static void iSeries_shutdown_IRQ(unsigned int irq);
  45 static void iSeries_enable_IRQ(unsigned int irq);
  46 static void iSeries_disable_IRQ(unsigned int irq);
  47 static void iSeries_end_IRQ(unsigned int irq);
  48
  49 static hw_irq_controller iSeries_IRQ_handler = {
  50         .typename = "iSeries irq controller",
  51         .startup = iSeries_startup_IRQ,
  52         .shutdown = iSeries_shutdown_IRQ,
  53         .enable = iSeries_enable_IRQ,
  54         .disable = iSeries_disable_IRQ,
  55         .end = iSeries_end_IRQ
  56 };
  57
  58 /* This maps virtual irq numbers to real irqs */
  59 unsigned int virt_irq_to_real_map[NR_IRQS];
  60
  61 /* The next available virtual irq number */
  62 /* Note: the pcnet32 driver assumes irq numbers < 2 aren't valid. :( */
  63 static int next_virtual_irq = 2;
  64
  65 /* This is called by init_IRQ.  set in ppc_md.init_IRQ by iSeries_setup.c */
  66 void __init iSeries_init_IRQ(void)
  67 {
  68         /* Register PCI event handler and open an event path */
  69         XmPciLpEvent_init();
  70 }
  71
  72 /*
  73  * This is called out of iSeries_scan_slot to allocate an IRQ for an EADS slot
  74  * It calculates the irq value for the slot.
  75  * Note that subBusNumber is always 0 (at the moment at least).
  76  */
  77 int __init iSeries_allocate_IRQ(HvBusNumber busNumber,
  78                 HvSubBusNumber subBusNumber, HvAgentId deviceId)
  79 {
  80         unsigned int realirq, virtirq;
  81         u8 idsel = (deviceId >> 4);
  82         u8 function = deviceId & 7;
  83
  84         virtirq = next_virtual_irq++;
  85         realirq = ((busNumber - 1) << 6) + ((idsel - 1) << 3) + function;
  86         virt_irq_to_real_map[virtirq] = realirq;
  87
  88         irq_desc[virtirq].handler = &iSeries_IRQ_handler;
  89         return virtirq;
  90 }
  91
  92 #define REAL_IRQ_TO_BUS(irq)    ((((irq) >> 6) & 0xff) + 1)
  93 #define REAL_IRQ_TO_IDSEL(irq)  ((((irq) >> 3) & 7) + 1)
  94 #define REAL_IRQ_TO_FUNC(irq)   ((irq) & 7)
  95
  96 /* This is called by iSeries_activate_IRQs */
  97 static unsigned int iSeries_startup_IRQ(unsigned int irq)
  98 {
  99         u32 bus, deviceId, function, mask;
 100         const u32 subBus = 0;
 101         unsigned int rirq = virt_irq_to_real_map[irq];
 102
 103         bus = REAL_IRQ_TO_BUS(rirq);
 104         function = REAL_IRQ_TO_FUNC(rirq);
 105         deviceId = (REAL_IRQ_TO_IDSEL(rirq) << 4) + function;
 106
 107         /* Link the IRQ number to the bridge */
 108         HvCallXm_connectBusUnit(bus, subBus, deviceId, irq);
 109
 110         /* Unmask bridge interrupts in the FISR */
 111         mask = 0x01010000 << function;
 112         HvCallPci_unmaskFisr(bus, subBus, deviceId, mask);
 113         return 0;
 114 }
 115
 116 /*
 117  * This is called out of iSeries_fixup to activate interrupt
 118  * generation for usable slots
 119  */
 120 void __init iSeries_activate_IRQs()
 121 {
 122         int irq;
 123         unsigned long flags;
 124
 125         for_each_irq (irq) {
 126                 irq_desc_t *desc = get_irq_desc(irq);
 127
 128                 if (desc && desc->handler && desc->handler->startup) {
 129                         spin_lock_irqsave(&desc->lock, flags);
 130                         desc->handler->startup(irq);
 131                         spin_unlock_irqrestore(&desc->lock, flags);
 132                 }
 133         }
 134 }
 135
 136 /*  this is not called anywhere currently */
 137 static void iSeries_shutdown_IRQ(unsigned int irq)
 138 {
 139         u32 bus, deviceId, function, mask;
 140         const u32 subBus = 0;
 141         unsigned int rirq = virt_irq_to_real_map[irq];
 142
 143         /* irq should be locked by the caller */
 144         bus = REAL_IRQ_TO_BUS(rirq);
 145         function = REAL_IRQ_TO_FUNC(rirq);
 146         deviceId = (REAL_IRQ_TO_IDSEL(rirq) << 4) + function;
 147
 148         /* Invalidate the IRQ number in the bridge */
 149         HvCallXm_connectBusUnit(bus, subBus, deviceId, 0);
 150
 151         /* Mask bridge interrupts in the FISR */
 152         mask = 0x01010000 << function;
 153         HvCallPci_maskFisr(bus, subBus, deviceId, mask);
 154 }
 155
 156 /*
 157  * This will be called by device drivers (via disable_IRQ)
 158  * to disable INTA in the bridge interrupt status register.
 159  */
 160 static void iSeries_disable_IRQ(unsigned int irq)
 161 {
 162         u32 bus, deviceId, function, mask;
 163         const u32 subBus = 0;
 164         unsigned int rirq = virt_irq_to_real_map[irq];
 165
 166         /* The IRQ has already been locked by the caller */
 167         bus = REAL_IRQ_TO_BUS(rirq);
 168         function = REAL_IRQ_TO_FUNC(rirq);
 169         deviceId = (REAL_IRQ_TO_IDSEL(rirq) << 4) + function;
 170
 171         /* Mask secondary INTA   */
 172         mask = 0x80000000;
 173         HvCallPci_maskInterrupts(bus, subBus, deviceId, mask);
 174         PPCDBG(PPCDBG_BUSWALK, "iSeries_disable_IRQ 0x%02X.%02X.%02X 0x%04X\n",
 175                bus, subBus, deviceId, irq);
 176 }
 177
 178 /*
 179  * This will be called by device drivers (via enable_IRQ)
 180  * to enable INTA in the bridge interrupt status register.
 181  */
 182 static void iSeries_enable_IRQ(unsigned int irq)
 183 {
 184         u32 bus, deviceId, function, mask;
 185         const u32 subBus = 0;
 186         unsigned int rirq = virt_irq_to_real_map[irq];
 187
 188         /* The IRQ has already been locked by the caller */
 189         bus = REAL_IRQ_TO_BUS(rirq);
 190         function = REAL_IRQ_TO_FUNC(rirq);
 191         deviceId = (REAL_IRQ_TO_IDSEL(rirq) << 4) + function;
 192
 193         /* Unmask secondary INTA */
 194         mask = 0x80000000;
 195         HvCallPci_unmaskInterrupts(bus, subBus, deviceId, mask);
 196         PPCDBG(PPCDBG_BUSWALK, "iSeries_enable_IRQ 0x%02X.%02X.%02X 0x%04X\n",
 197                bus, subBus, deviceId, irq);
 198 }
 199
 200 /*
 201  * Need to define this so ppc_irq_dispatch_handler will NOT call
 202  * enable_IRQ at the end of interrupt handling.  However, this does
 203  * nothing because there is not enough information provided to do
 204  * the EOI HvCall.  This is done by XmPciLpEvent.c
 205  */
 206 static void iSeries_end_IRQ(unsigned int irq)
 207 {
 208 }