arch/alpha/kernel/sys_eiger.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *      linux/arch/alpha/kernel/sys_eiger.c
   4  *
   5  *      Copyright (C) 1995 David A Rusling
   6  *      Copyright (C) 1996, 1999 Jay A Estabrook
   7  *      Copyright (C) 1998, 1999 Richard Henderson
   8  *      Copyright (C) 1999 Iain Grant
   9  *
  10  * Code supporting the EIGER (EV6+TSUNAMI).
  11  */
  12
  13 #include <linux/kernel.h>
  14 #include <linux/types.h>
  15 #include <linux/mm.h>
  16 #include <linux/sched.h>
  17 #include <linux/pci.h>
  18 #include <linux/init.h>
  19 #include <linux/bitops.h>
  20
  21 #include <asm/ptrace.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/pgtable.h>
  27 #include <asm/core_tsunami.h>
  28 #include <asm/hwrpb.h>
  29 #include <asm/tlbflush.h>
  30
  31 #include "proto.h"
  32 #include "irq_impl.h"
  33 #include "pci_impl.h"
  34 #include "machvec_impl.h"
  35
  36
  37 /* Note that this interrupt code is identical to TAKARA.  */
  38
  39 /* Note mask bit is true for DISABLED irqs.  */
  40 static unsigned long cached_irq_mask[2] = { -1, -1 };
  41
  42 static inline void
  43 eiger_update_irq_hw(unsigned long irq, unsigned long mask)
  44 {
  45         int regaddr;
  46
  47         mask = (irq >= 64 ? mask << 16 : mask >> ((irq - 16) & 0x30));
  48         regaddr = 0x510 + (((irq - 16) >> 2) & 0x0c);
  49         outl(mask & 0xffff0000UL, regaddr);
  50 }
  51
  52 static inline void
  53 eiger_enable_irq(struct irq_data *d)
  54 {
  55         unsigned int irq = d->irq;
  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(struct irq_data *d)
  63 {
  64         unsigned int irq = d->irq;
  65         unsigned long mask;
  66         mask = (cached_irq_mask[irq >= 64] |= 1UL << (irq & 63));
  67         eiger_update_irq_hw(irq, mask);
  68 }
  69
  70 static struct irq_chip eiger_irq_type = {
  71         .name           = "EIGER",
  72         .irq_unmask     = eiger_enable_irq,
  73         .irq_mask       = eiger_disable_irq,
  74         .irq_mask_ack   = eiger_disable_irq,
  75 };
  76
  77 static void
  78 eiger_device_interrupt(unsigned long vector)
  79 {
  80         unsigned intstatus;
  81
  82         /*
  83          * The PALcode will have passed us vectors 0x800 or 0x810,
  84          * which are fairly arbitrary values and serve only to tell
  85          * us whether an interrupt has come in on IRQ0 or IRQ1. If
  86          * it's IRQ1 it's a PCI interrupt; if it's IRQ0, it's
  87          * probably ISA, but PCI interrupts can come through IRQ0
  88          * as well if the interrupt controller isn't in accelerated
  89          * mode.
  90          *
  91          * OTOH, the accelerator thing doesn't seem to be working
  92          * overly well, so what we'll do instead is try directly
  93          * examining the Master Interrupt Register to see if it's a
  94          * PCI interrupt, and if _not_ then we'll pass it on to the
  95          * ISA handler.
  96          */
  97
  98         intstatus = inw(0x500) & 15;
  99         if (intstatus) {
 100                 /*
 101                  * This is a PCI interrupt. Check each bit and
 102                  * despatch an interrupt if it's set.
 103                  */
 104
 105                 if (intstatus & 8) handle_irq(16+3);
 106                 if (intstatus & 4) handle_irq(16+2);
 107                 if (intstatus & 2) handle_irq(16+1);
 108                 if (intstatus & 1) handle_irq(16+0);
 109         } else {
 110                 isa_device_interrupt(vector);
 111         }
 112 }
 113
 114 static void
 115 eiger_srm_device_interrupt(unsigned long vector)
 116 {
 117         int irq = (vector - 0x800) >> 4;
 118         handle_irq(irq);
 119 }
 120
 121 static void __init
 122 eiger_init_irq(void)
 123 {
 124         long i;
 125
 126         outb(0, DMA1_RESET_REG);
 127         outb(0, DMA2_RESET_REG);
 128         outb(DMA_MODE_CASCADE, DMA2_MODE_REG);
 129         outb(0, DMA2_MASK_REG);
 130
 131         if (alpha_using_srm)
 132                 alpha_mv.device_interrupt = eiger_srm_device_interrupt;
 133
 134         for (i = 16; i < 128; i += 16)
 135                 eiger_update_irq_hw(i, -1);
 136
 137         init_i8259a_irqs();
 138
 139         for (i = 16; i < 128; ++i) {
 140                 irq_set_chip_and_handler(i, &eiger_irq_type, handle_level_irq);
 141                 irq_set_status_flags(i, IRQ_LEVEL);
 142         }
 143 }
 144
 145 static int
 146 eiger_map_irq(const struct pci_dev *dev, u8 slot, u8 pin)
 147 {
 148         u8 irq_orig;
 149
 150         /* The SRM console has already calculated out the IRQ value's for
 151            option cards. As this works lets just read in the value already
 152            set and change it to a useable value by Linux.
 153
 154            All the IRQ values generated by the console are greater than 90,
 155            so we subtract 80 because it is (90 - allocated ISA IRQ's).  */
 156
 157         pci_read_config_byte(dev, PCI_INTERRUPT_LINE, &irq_orig);
 158
 159         return irq_orig - 0x80;
 160 }
 161
 162 static u8
 163 eiger_swizzle(struct pci_dev *dev, u8 *pinp)
 164 {
 165         struct pci_controller *hose = dev->sysdata;
 166         int slot, pin = *pinp;
 167         int bridge_count = 0;
 168
 169         /* Find the number of backplane bridges.  */
 170         int backplane = inw(0x502) & 0x0f;
 171
 172         switch (backplane)
 173         {
 174            case 0x00: bridge_count = 0; break; /* No bridges */
 175            case 0x01: bridge_count = 1; break; /* 1 */
 176            case 0x03: bridge_count = 2; break; /* 2 */
 177            case 0x07: bridge_count = 3; break; /* 3 */
 178            case 0x0f: bridge_count = 4; break; /* 4 */
 179         };
 180
 181         slot = PCI_SLOT(dev->devfn);
 182         while (dev->bus->self) {
 183                 /* Check for built-in bridges on hose 0. */
 184                 if (hose->index == 0
 185                     && (PCI_SLOT(dev->bus->self->devfn)
 186                         > 20 - bridge_count)) {
 187                         slot = PCI_SLOT(dev->devfn);
 188                         break;
 189                 }
 190                 /* Must be a card-based bridge.  */
 191                 pin = pci_swizzle_interrupt_pin(dev, pin);
 192
 193                 /* Move up the chain of bridges.  */
 194                 dev = dev->bus->self;
 195         }
 196         *pinp = pin;
 197         return slot;
 198 }
 199
 200 /*
 201  * The System Vectors
 202  */
 203
 204 struct alpha_machine_vector eiger_mv __initmv = {
 205         .vector_name            = "Eiger",
 206         DO_EV6_MMU,
 207         DO_DEFAULT_RTC,
 208         DO_TSUNAMI_IO,
 209         .machine_check          = tsunami_machine_check,
 210         .max_isa_dma_address    = ALPHA_MAX_ISA_DMA_ADDRESS,
 211         .min_io_address         = DEFAULT_IO_BASE,
 212         .min_mem_address        = DEFAULT_MEM_BASE,
 213         .pci_dac_offset         = TSUNAMI_DAC_OFFSET,
 214
 215         .nr_irqs                = 128,
 216         .device_interrupt       = eiger_device_interrupt,
 217
 218         .init_arch              = tsunami_init_arch,
 219         .init_irq               = eiger_init_irq,
 220         .init_rtc               = common_init_rtc,
 221         .init_pci               = common_init_pci,
 222         .kill_arch              = tsunami_kill_arch,
 223         .pci_map_irq            = eiger_map_irq,
 224         .pci_swizzle            = eiger_swizzle,
 225 };
 226 ALIAS_MV(eiger)