arch/alpha/kernel/sys_eiger.c

   1 /*
   2  *      linux/arch/alpha/kernel/sys_eiger.c
   3  *
   4  *      Copyright (C) 1995 David A Rusling
   5  *      Copyright (C) 1996, 1999 Jay A Estabrook
   6  *      Copyright (C) 1998, 1999 Richard Henderson
   7  *      Copyright (C) 1999 Iain Grant
   8  *
   9  * Code supporting the EIGER (EV6+TSUNAMI).
  10  */
  11
  12 #include <linux/kernel.h>
  13 #include <linux/types.h>
  14 #include <linux/mm.h>
  15 #include <linux/sched.h>
  16 #include <linux/pci.h>
  17 #include <linux/init.h>
  18 #include <linux/bitops.h>
  19
  20 #include <asm/ptrace.h>
  21 #include <asm/system.h>
  22 #include <asm/dma.h>
  23 #include <asm/irq.h>
  24 #include <asm/mmu_context.h>
  25 #include <asm/io.h>
  26 #include <asm/pci.h>
  27 #include <asm/pgtable.h>
  28 #include <asm/core_tsunami.h>
  29 #include <asm/hwrpb.h>
  30 #include <asm/tlbflush.h>
  31
  32 #include "proto.h"
  33 #include "irq_impl.h"
  34 #include "pci_impl.h"
  35 #include "machvec_impl.h"
  36
  37
  38 /* Note that this interrupt code is identical to TAKARA.  */
  39
  40 /* Note mask bit is true for DISABLED irqs.  */
  41 static unsigned long cached_irq_mask[2] = { -1, -1 };
  42
  43 static inline void
  44 eiger_update_irq_hw(unsigned long irq, unsigned long mask)
  45 {
  46         int regaddr;
  47
  48         mask = (irq >= 64 ? mask << 16 : mask >> ((irq - 16) & 0x30));
  49         regaddr = 0x510 + (((irq - 16) >> 2) & 0x0c);
  50         outl(mask & 0xffff0000UL, regaddr);
  51 }
  52
  53 static inline void
  54 eiger_enable_irq(unsigned int irq)
  55 {
  56         unsigned long mask;
  57         mask = (cached_irq_mask[irq >= 64] &= ~(1UL << (irq & 63)));
  58         eiger_update_irq_hw(irq, mask);
  59 }
  60
  61 static void
  62 eiger_disable_irq(unsigned int irq)
  63 {
  64         unsigned long mask;
  65         mask = (cached_irq_mask[irq >= 64] |= 1UL << (irq & 63));
  66         eiger_update_irq_hw(irq, mask);
  67 }
  68
  69 static unsigned int
  70 eiger_startup_irq(unsigned int irq)
  71 {
  72         eiger_enable_irq(irq);
  73         return 0; /* never anything pending */
  74 }
  75
  76 static void
  77 eiger_end_irq(unsigned int irq)
  78 {
  79         if (!(irq_desc[irq].status & (IRQ_DISABLED|IRQ_INPROGRESS)))
  80                 eiger_enable_irq(irq);
  81 }
  82
  83 static struct hw_interrupt_type eiger_irq_type = {
  84         .typename       = "EIGER",
  85         .startup        = eiger_startup_irq,
  86         .shutdown       = eiger_disable_irq,
  87         .enable         = eiger_enable_irq,
  88         .disable        = eiger_disable_irq,
  89         .ack            = eiger_disable_irq,
  90         .end            = eiger_end_irq,
  91 };
  92
  93 static void
  94 eiger_device_interrupt(unsigned long vector)
  95 {
  96         unsigned intstatus;
  97
  98         /*
  99          * The PALcode will have passed us vectors 0x800 or 0x810,
 100          * which are fairly arbitrary values and serve only to tell
 101          * us whether an interrupt has come in on IRQ0 or IRQ1. If
 102          * it's IRQ1 it's a PCI interrupt; if it's IRQ0, it's
 103          * probably ISA, but PCI interrupts can come through IRQ0
 104          * as well if the interrupt controller isn't in accelerated
 105          * mode.
 106          *
 107          * OTOH, the accelerator thing doesn't seem to be working
 108          * overly well, so what we'll do instead is try directly
 109          * examining the Master Interrupt Register to see if it's a
 110          * PCI interrupt, and if _not_ then we'll pass it on to the
 111          * ISA handler.
 112          */
 113
 114         intstatus = inw(0x500) & 15;
 115         if (intstatus) {
 116                 /*
 117                  * This is a PCI interrupt. Check each bit and
 118                  * despatch an interrupt if it's set.
 119                  */
 120
 121                 if (intstatus & 8) handle_irq(16+3);
 122                 if (intstatus & 4) handle_irq(16+2);
 123                 if (intstatus & 2) handle_irq(16+1);
 124                 if (intstatus & 1) handle_irq(16+0);
 125         } else {
 126                 isa_device_interrupt(vector);
 127         }
 128 }
 129
 130 static void
 131 eiger_srm_device_interrupt(unsigned long vector)
 132 {
 133         int irq = (vector - 0x800) >> 4;
 134         handle_irq(irq);
 135 }
 136
 137 static void __init
 138 eiger_init_irq(void)
 139 {
 140         long i;
 141
 142         outb(0, DMA1_RESET_REG);
 143         outb(0, DMA2_RESET_REG);
 144         outb(DMA_MODE_CASCADE, DMA2_MODE_REG);
 145         outb(0, DMA2_MASK_REG);
 146
 147         if (alpha_using_srm)
 148                 alpha_mv.device_interrupt = eiger_srm_device_interrupt;
 149
 150         for (i = 16; i < 128; i += 16)
 151                 eiger_update_irq_hw(i, -1);
 152
 153         init_i8259a_irqs();
 154
 155         for (i = 16; i < 128; ++i) {
 156                 irq_desc[i].status = IRQ_DISABLED | IRQ_LEVEL;
 157                 irq_desc[i].chip = &eiger_irq_type;
 158         }
 159 }
 160
 161 static int __init
 162 eiger_map_irq(struct pci_dev *dev, u8 slot, u8 pin)
 163 {
 164         u8 irq_orig;
 165
 166         /* The SRM console has already calculated out the IRQ value's for
 167            option cards. As this works lets just read in the value already
 168            set and change it to a useable value by Linux.
 169
 170            All the IRQ values generated by the console are greater than 90,
 171            so we subtract 80 because it is (90 - allocated ISA IRQ's).  */
 172
 173         pci_read_config_byte(dev, PCI_INTERRUPT_LINE, &irq_orig);
 174
 175         return irq_orig - 0x80;
 176 }
 177
 178 static u8 __init
 179 eiger_swizzle(struct pci_dev *dev, u8 *pinp)
 180 {
 181         struct pci_controller *hose = dev->sysdata;
 182         int slot, pin = *pinp;
 183         int bridge_count = 0;
 184
 185         /* Find the number of backplane bridges.  */
 186         int backplane = inw(0x502) & 0x0f;
 187
 188         switch (backplane)
 189         {
 190            case 0x00: bridge_count = 0; break; /* No bridges */
 191            case 0x01: bridge_count = 1; break; /* 1 */
 192            case 0x03: bridge_count = 2; break; /* 2 */
 193            case 0x07: bridge_count = 3; break; /* 3 */
 194            case 0x0f: bridge_count = 4; break; /* 4 */
 195         };
 196
 197         slot = PCI_SLOT(dev->devfn);
 198         while (dev->bus->self) {
 199                 /* Check for built-in bridges on hose 0. */
 200                 if (hose->index == 0
 201                     && (PCI_SLOT(dev->bus->self->devfn)
 202                         > 20 - bridge_count)) {
 203                         slot = PCI_SLOT(dev->devfn);
 204                         break;
 205                 }
 206                 /* Must be a card-based bridge.  */
 207                 pin = bridge_swizzle(pin, PCI_SLOT(dev->devfn));
 208
 209                 /* Move up the chain of bridges.  */
 210                 dev = dev->bus->self;
 211         }
 212         *pinp = pin;
 213         return slot;
 214 }
 215
 216 /*
 217  * The System Vectors
 218  */
 219
 220 struct alpha_machine_vector eiger_mv __initmv = {
 221         .vector_name            = "Eiger",
 222         DO_EV6_MMU,
 223         DO_DEFAULT_RTC,
 224         DO_TSUNAMI_IO,
 225         .machine_check          = tsunami_machine_check,
 226         .max_isa_dma_address    = ALPHA_MAX_ISA_DMA_ADDRESS,
 227         .min_io_address         = DEFAULT_IO_BASE,
 228         .min_mem_address        = DEFAULT_MEM_BASE,
 229         .pci_dac_offset         = TSUNAMI_DAC_OFFSET,
 230
 231         .nr_irqs                = 128,
 232         .device_interrupt       = eiger_device_interrupt,
 233
 234         .init_arch              = tsunami_init_arch,
 235         .init_irq               = eiger_init_irq,
 236         .init_rtc               = common_init_rtc,
 237         .init_pci               = common_init_pci,
 238         .kill_arch              = tsunami_kill_arch,
 239         .pci_map_irq            = eiger_map_irq,
 240         .pci_swizzle            = eiger_swizzle,
 241 };
 242 ALIAS_MV(eiger)