sys_mikasa.c

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/*
 *  linux/arch/alpha/kernel/sys_mikasa.c
 *
 *  Copyright (C) 1995 David A Rusling
 *  Copyright (C) 1996 Jay A Estabrook
 *  Copyright (C) 1998, 1999 Richard Henderson
 *
 * Code supporting the MIKASA (AlphaServer 1000).
 */

#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/mm.h>
#include <linux/sched.h>
#include <linux/pci.h>
#include <linux/init.h>
#include <linux/bitops.h>

#include <asm/ptrace.h>
#include <asm/mce.h>
#include <asm/dma.h>
#include <asm/irq.h>
#include <asm/mmu_context.h>
#include <asm/io.h>
#include <asm/pgtable.h>
#include <asm/core_apecs.h>
#include <asm/core_cia.h>
#include <asm/tlbflush.h>

#include "proto.h"
#include "irq_impl.h"
#include "pci_impl.h"
#include "machvec_impl.h"


/* Note mask bit is true for ENABLED irqs.  */
static int cached_irq_mask;

static inline void
mikasa_update_irq_hw(int mask)
{
    outw(mask, 0x536);
}

static inline void
mikasa_enable_irq(struct irq_data *d)
{
    mikasa_update_irq_hw(cached_irq_mask |= 1 << (d->irq - 16));
}

static void
mikasa_disable_irq(struct irq_data *d)
{
    mikasa_update_irq_hw(cached_irq_mask &= ~(1 << (d->irq - 16)));
}

static struct irq_chip mikasa_irq_type = {
    .name       = "MIKASA",
    .irq_unmask = mikasa_enable_irq,
    .irq_mask   = mikasa_disable_irq,
    .irq_mask_ack   = mikasa_disable_irq,
};

static void 
mikasa_device_interrupt(unsigned long vector)
{
    unsigned long pld;
    unsigned int i;

    /* Read the interrupt summary registers */
    pld = (((~inw(0x534) & 0x0000ffffUL) << 16)
           | (((unsigned long) inb(0xa0)) << 8)
           | inb(0x20));

    /*
     * Now for every possible bit set, work through them and call
     * the appropriate interrupt handler.
     */
    while (pld) {
        i = ffz(~pld);
        pld &= pld - 1; /* clear least bit set */
        if (i < 16) {
            isa_device_interrupt(vector);
        } else {
            handle_irq(i);
        }
    }
}

static void __init
mikasa_init_irq(void)
{
    long i;

    if (alpha_using_srm)
        alpha_mv.device_interrupt = srm_device_interrupt;

    mikasa_update_irq_hw(0);

    for (i = 16; i < 32; ++i) {
        irq_set_chip_and_handler(i, &mikasa_irq_type,
                     handle_level_irq);
        irq_set_status_flags(i, IRQ_LEVEL);
    }

    init_i8259a_irqs();
    common_init_isa_dma();
}


/*
 * PCI Fixup configuration.
 *
 * Summary @ 0x536:
 * Bit      Meaning
 * 0        Interrupt Line A from slot 0
 * 1        Interrupt Line B from slot 0
 * 2        Interrupt Line C from slot 0
 * 3        Interrupt Line D from slot 0
 * 4        Interrupt Line A from slot 1
 * 5        Interrupt line B from slot 1
 * 6        Interrupt Line C from slot 1
 * 7        Interrupt Line D from slot 1
 * 8        Interrupt Line A from slot 2
 * 9        Interrupt Line B from slot 2
 *10        Interrupt Line C from slot 2
 *11        Interrupt Line D from slot 2
 *12        NCR 810 SCSI
 *13        Power Supply Fail
 *14        Temperature Warn
 *15        Reserved
 *
 * The device to slot mapping looks like:
 *
 * Slot     Device
 *  6       NCR SCSI controller
 *  7       Intel PCI-EISA bridge chip
 * 11       PCI on board slot 0
 * 12       PCI on board slot 1
 * 13       PCI on board slot 2
 *   
 *
 * This two layered interrupt approach means that we allocate IRQ 16 and 
 * above for PCI interrupts.  The IRQ relates to which bit the interrupt
 * comes in on.  This makes interrupt processing much easier.
 */

static int __init
mikasa_map_irq(const struct pci_dev *dev, u8 slot, u8 pin)
{
    static char irq_tab[8][5] __initdata = {
        /*INT    INTA   INTB   INTC   INTD */
        {16+12, 16+12, 16+12, 16+12, 16+12},    /* IdSel 17,  SCSI */
        {   -1,    -1,    -1,    -1,    -1},    /* IdSel 18,  PCEB */
        {   -1,    -1,    -1,    -1,    -1},    /* IdSel 19,  ???? */
        {   -1,    -1,    -1,    -1,    -1},    /* IdSel 20,  ???? */
        {   -1,    -1,    -1,    -1,    -1},    /* IdSel 21,  ???? */
        { 16+0,  16+0,  16+1,  16+2,  16+3},    /* IdSel 22,  slot 0 */
        { 16+4,  16+4,  16+5,  16+6,  16+7},    /* IdSel 23,  slot 1 */
        { 16+8,  16+8,  16+9, 16+10, 16+11},    /* IdSel 24,  slot 2 */
    };
    const long min_idsel = 6, max_idsel = 13, irqs_per_slot = 5;
    return COMMON_TABLE_LOOKUP;
}


#if defined(CONFIG_ALPHA_GENERIC) || !defined(CONFIG_ALPHA_PRIMO)
static void
mikasa_apecs_machine_check(unsigned long vector, unsigned long la_ptr)
{
#define MCHK_NO_DEVSEL 0x205U
#define MCHK_NO_TABT 0x204U

    struct el_common *mchk_header;
    unsigned int code;

    mchk_header = (struct el_common *)la_ptr;

    /* Clear the error before any reporting.  */
    mb();
    mb(); /* magic */
    draina();
    apecs_pci_clr_err();
    wrmces(0x7);
    mb();

    code = mchk_header->code;
    process_mcheck_info(vector, la_ptr, "MIKASA APECS",
                (mcheck_expected(0)
                 && (code == MCHK_NO_DEVSEL
                     || code == MCHK_NO_TABT)));
}
#endif


/*
 * The System Vector
 */

#if defined(CONFIG_ALPHA_GENERIC) || !defined(CONFIG_ALPHA_PRIMO)
struct alpha_machine_vector mikasa_mv __initmv = {
    .vector_name        = "Mikasa",
    DO_EV4_MMU,
    DO_DEFAULT_RTC,
    DO_APECS_IO,
    .machine_check      = mikasa_apecs_machine_check,
    .max_isa_dma_address    = ALPHA_MAX_ISA_DMA_ADDRESS,
    .min_io_address     = DEFAULT_IO_BASE,
    .min_mem_address    = APECS_AND_LCA_DEFAULT_MEM_BASE,

    .nr_irqs        = 32,
    .device_interrupt   = mikasa_device_interrupt,

    .init_arch      = apecs_init_arch,
    .init_irq       = mikasa_init_irq,
    .init_rtc       = common_init_rtc,
    .init_pci       = common_init_pci,
    .pci_map_irq        = mikasa_map_irq,
    .pci_swizzle        = common_swizzle,
};
ALIAS_MV(mikasa)
#endif

#if defined(CONFIG_ALPHA_GENERIC) || defined(CONFIG_ALPHA_PRIMO)
struct alpha_machine_vector mikasa_primo_mv __initmv = {
    .vector_name        = "Mikasa-Primo",
    DO_EV5_MMU,
    DO_DEFAULT_RTC,
    DO_CIA_IO,
    .machine_check      = cia_machine_check,
    .max_isa_dma_address    = ALPHA_MAX_ISA_DMA_ADDRESS,
    .min_io_address     = DEFAULT_IO_BASE,
    .min_mem_address    = CIA_DEFAULT_MEM_BASE,

    .nr_irqs        = 32,
    .device_interrupt   = mikasa_device_interrupt,

    .init_arch      = cia_init_arch,
    .init_irq       = mikasa_init_irq,
    .init_rtc       = common_init_rtc,
    .init_pci       = cia_init_pci,
    .kill_arch      = cia_kill_arch,
    .pci_map_irq        = mikasa_map_irq,
    .pci_swizzle        = common_swizzle,
};
ALIAS_MV(mikasa_primo)
#endif