arch/alpha/kernel/sys_mikasa.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *      linux/arch/alpha/kernel/sys_mikasa.c
   4  *
   5  *      Copyright (C) 1995 David A Rusling
   6  *      Copyright (C) 1996 Jay A Estabrook
   7  *      Copyright (C) 1998, 1999 Richard Henderson
   8  *
   9  * Code supporting the MIKASA (AlphaServer 1000).
  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/mce.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/core_cia.h>
  27 #include <asm/tlbflush.h>
  28
  29 #include "proto.h"
  30 #include "irq_impl.h"
  31 #include "pci_impl.h"
  32 #include "machvec_impl.h"
  33
  34
  35 /* Note mask bit is true for ENABLED irqs.  */
  36 static int cached_irq_mask;
  37
  38 static inline void
  39 mikasa_update_irq_hw(int mask)
  40 {
  41         outw(mask, 0x536);
  42 }
  43
  44 static inline void
  45 mikasa_enable_irq(struct irq_data *d)
  46 {
  47         mikasa_update_irq_hw(cached_irq_mask |= 1 << (d->irq - 16));
  48 }
  49
  50 static void
  51 mikasa_disable_irq(struct irq_data *d)
  52 {
  53         mikasa_update_irq_hw(cached_irq_mask &= ~(1 << (d->irq - 16)));
  54 }
  55
  56 static struct irq_chip mikasa_irq_type = {
  57         .name           = "MIKASA",
  58         .irq_unmask     = mikasa_enable_irq,
  59         .irq_mask       = mikasa_disable_irq,
  60         .irq_mask_ack   = mikasa_disable_irq,
  61 };
  62
  63 static void
  64 mikasa_device_interrupt(unsigned long vector)
  65 {
  66         unsigned long pld;
  67         unsigned int i;
  68
  69         /* Read the interrupt summary registers */
  70         pld = (((~inw(0x534) & 0x0000ffffUL) << 16)
  71                | (((unsigned long) inb(0xa0)) << 8)
  72                | inb(0x20));
  73
  74         /*
  75          * Now for every possible bit set, work through them and call
  76          * the appropriate interrupt handler.
  77          */
  78         while (pld) {
  79                 i = ffz(~pld);
  80                 pld &= pld - 1; /* clear least bit set */
  81                 if (i < 16) {
  82                         isa_device_interrupt(vector);
  83                 } else {
  84                         handle_irq(i);
  85                 }
  86         }
  87 }
  88
  89 static void __init
  90 mikasa_init_irq(void)
  91 {
  92         long i;
  93
  94         if (alpha_using_srm)
  95                 alpha_mv.device_interrupt = srm_device_interrupt;
  96
  97         mikasa_update_irq_hw(0);
  98
  99         for (i = 16; i < 32; ++i) {
 100                 irq_set_chip_and_handler(i, &mikasa_irq_type,
 101                                          handle_level_irq);
 102                 irq_set_status_flags(i, IRQ_LEVEL);
 103         }
 104
 105         init_i8259a_irqs();
 106         common_init_isa_dma();
 107 }
 108
 109
 110 /*
 111  * PCI Fixup configuration.
 112  *
 113  * Summary @ 0x536:
 114  * Bit      Meaning
 115  * 0        Interrupt Line A from slot 0
 116  * 1        Interrupt Line B from slot 0
 117  * 2        Interrupt Line C from slot 0
 118  * 3        Interrupt Line D from slot 0
 119  * 4        Interrupt Line A from slot 1
 120  * 5        Interrupt line B from slot 1
 121  * 6        Interrupt Line C from slot 1
 122  * 7        Interrupt Line D from slot 1
 123  * 8        Interrupt Line A from slot 2
 124  * 9        Interrupt Line B from slot 2
 125  *10        Interrupt Line C from slot 2
 126  *11        Interrupt Line D from slot 2
 127  *12        NCR 810 SCSI
 128  *13        Power Supply Fail
 129  *14        Temperature Warn
 130  *15        Reserved
 131  *
 132  * The device to slot mapping looks like:
 133  *
 134  * Slot     Device
 135  *  6       NCR SCSI controller
 136  *  7       Intel PCI-EISA bridge chip
 137  * 11       PCI on board slot 0
 138  * 12       PCI on board slot 1
 139  * 13       PCI on board slot 2
 140  *
 141  *
 142  * This two layered interrupt approach means that we allocate IRQ 16 and
 143  * above for PCI interrupts.  The IRQ relates to which bit the interrupt
 144  * comes in on.  This makes interrupt processing much easier.
 145  */
 146
 147 static int
 148 mikasa_map_irq(const struct pci_dev *dev, u8 slot, u8 pin)
 149 {
 150         static char irq_tab[8][5] = {
 151                 /*INT    INTA   INTB   INTC   INTD */
 152                 {16+12, 16+12, 16+12, 16+12, 16+12},    /* IdSel 17,  SCSI */
 153                 {   -1,    -1,    -1,    -1,    -1},    /* IdSel 18,  PCEB */
 154                 {   -1,    -1,    -1,    -1,    -1},    /* IdSel 19,  ???? */
 155                 {   -1,    -1,    -1,    -1,    -1},    /* IdSel 20,  ???? */
 156                 {   -1,    -1,    -1,    -1,    -1},    /* IdSel 21,  ???? */
 157                 { 16+0,  16+0,  16+1,  16+2,  16+3},    /* IdSel 22,  slot 0 */
 158                 { 16+4,  16+4,  16+5,  16+6,  16+7},    /* IdSel 23,  slot 1 */
 159                 { 16+8,  16+8,  16+9, 16+10, 16+11},    /* IdSel 24,  slot 2 */
 160         };
 161         const long min_idsel = 6, max_idsel = 13, irqs_per_slot = 5;
 162         return COMMON_TABLE_LOOKUP;
 163 }
 164
 165
 166 /*
 167  * The System Vector
 168  */
 169 struct alpha_machine_vector mikasa_primo_mv __initmv = {
 170         .vector_name            = "Mikasa-Primo",
 171         DO_EV5_MMU,
 172         DO_DEFAULT_RTC,
 173         DO_CIA_IO,
 174         .machine_check          = cia_machine_check,
 175         .max_isa_dma_address    = ALPHA_MAX_ISA_DMA_ADDRESS,
 176         .min_io_address         = DEFAULT_IO_BASE,
 177         .min_mem_address        = CIA_DEFAULT_MEM_BASE,
 178
 179         .nr_irqs                = 32,
 180         .device_interrupt       = mikasa_device_interrupt,
 181
 182         .init_arch              = cia_init_arch,
 183         .init_irq               = mikasa_init_irq,
 184         .init_rtc               = common_init_rtc,
 185         .init_pci               = cia_init_pci,
 186         .kill_arch              = cia_kill_arch,
 187         .pci_map_irq            = mikasa_map_irq,
 188         .pci_swizzle            = common_swizzle,
 189 };
 190 ALIAS_MV(mikasa_primo)