/* $NetBSD: pci_kn300.c,v 1.43 2021/07/04 22:42:36 thorpej Exp $ */

/*
 * Copyright (c) 1998 by Matthew Jacob
 * NASA AMES Research Center.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice immediately at the beginning of the file, without modification,
 *    this list of conditions, and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/cdefs.h>                  /* RCS ID & Copyright macro defns */

__KERNEL_RCSID(0, "$NetBSD: pci_kn300.c,v 1.43 2021/07/04 22:42:36 thorpej Exp $");

#include <sys/types.h>
#include <sys/param.h>
#include <sys/time.h>
#include <sys/systm.h>
#include <sys/errno.h>
#include <sys/device.h>
#include <sys/cpu.h>
#include <sys/syslog.h>

#include <machine/autoconf.h>
#include <machine/rpb.h>

#include <dev/pci/pcireg.h>
#include <dev/pci/pcivar.h>

#include <alpha/mcbus/mcbusvar.h>
#include <alpha/mcbus/mcbusreg.h>
#include <alpha/pci/mcpciareg.h>
#include <alpha/pci/mcpciavar.h>

#include "sio.h"
#if NSIO > 0 || NPCEB > 0
#include <alpha/pci/siovar.h>
#endif

static int      dec_kn300_intr_map(const struct pci_attach_args *,
                    pci_intr_handle_t *);
static const char *dec_kn300_intr_string(pci_chipset_tag_t, pci_intr_handle_t,
                    char *, size_t);
static const struct evcnt *dec_kn300_intr_evcnt(pci_chipset_tag_t,
                    pci_intr_handle_t);
static void     *dec_kn300_intr_establish(pci_chipset_tag_t,
                    pci_intr_handle_t, int, int (*func)(void *), void *);
static void     dec_kn300_intr_disestablish(pci_chipset_tag_t, void *);

#define KN300_PCEB_IRQ  16
#define KN300_STRAY_MAX 25
#define NPIN            4

#define NIRQ    (MAX_MC_BUS * MCPCIA_PER_MCBUS * MCPCIA_MAXSLOT * NPIN)
static int savirqs[NIRQ];

static struct alpha_shared_intr *kn300_pci_intr;

static struct mcpcia_config *mcpcia_eisaccp = NULL;

static void     kn300_iointr(void *, unsigned long);
static void     kn300_enable_intr(struct mcpcia_config *, int);
static void     kn300_disable_intr(struct mcpcia_config *, int);

static void
pci_kn300_pickintr(void *core, bus_space_tag_t iot, bus_space_tag_t memt,
    pci_chipset_tag_t pc)
{
        struct mcpcia_config *ccp = core;
        struct evcnt *ev;
        const char *cp;

        if (kn300_pci_intr == NULL) {
                int g;

                kn300_pci_intr = alpha_shared_intr_alloc(NIRQ);
                for (g = 0; g < NIRQ; g++) {
                        alpha_shared_intr_set_maxstrays(kn300_pci_intr, g,
                            KN300_STRAY_MAX);

                        ev = alpha_shared_intr_evcnt(kn300_pci_intr, g);
                        cp = alpha_shared_intr_string(kn300_pci_intr, g);

                        evcnt_attach_dynamic(ev, EVCNT_TYPE_INTR, NULL,
                            "kn300", cp);

                        savirqs[g] = (char) -1;
                }
        }

        pc->pc_intr_v = core;
        pc->pc_intr_map = dec_kn300_intr_map;
        pc->pc_intr_string = dec_kn300_intr_string;
        pc->pc_intr_evcnt = dec_kn300_intr_evcnt;
        pc->pc_intr_establish = dec_kn300_intr_establish;
        pc->pc_intr_disestablish = dec_kn300_intr_disestablish;

        /* Not supported on KN300. */
        pc->pc_pciide_compat_intr_establish = NULL;

        if (EISA_PRESENT(REGVAL(MCPCIA_PCI_REV(ccp)))) {
                mcpcia_eisaccp = ccp;
#if NSIO > 0 || NPCEB > 0
                sio_intr_setup(pc, &ccp->cc_iot);
                kn300_enable_intr(ccp, KN300_PCEB_IRQ);
#endif
        }
}
ALPHA_PCI_INTR_INIT(ST_DEC_4100, pci_kn300_pickintr)

static int
dec_kn300_intr_map(const struct pci_attach_args *pa, pci_intr_handle_t *ihp)
{
        pcitag_t bustag = pa->pa_intrtag;
        int buspin = pa->pa_intrpin;
        pci_chipset_tag_t pc = pa->pa_pc;
        struct mcpcia_config *ccp = (struct mcpcia_config *)pc->pc_intr_v;
        int device;
        int mcpcia_irq;

        if (buspin == 0) {
                /* No IRQ used. */
                return 1;
        }
        if (buspin < 0 || buspin > 4) {
                printf("dec_kn300_intr_map: bad interrupt pin %d\n", buspin);
                return 1;
        }

        pci_decompose_tag(pc, bustag, NULL, &device, NULL);

        /*
         * On MID 5 device 1 is the internal NCR 53c810.
         */
        if (ccp->cc_mid == 5 && device == 1) {
                mcpcia_irq = 16;
        } else if (device >= 2 && device <= 5) {
                mcpcia_irq = (device - 2) * 4 + buspin - 1;
        } else {
                printf("dec_kn300_intr_map: weird device number %d\n", device);
                return(1);
        }

        /*
         * handle layout:
         *
         *      Determine kn300 IRQ (encoded in SCB vector):
         *      bits 0..1       buspin-1
         *      bits 2..4       PCI Slot (0..7- yes, some don't exist)
         *      bits 5..7       MID-4
         *      bits 8..10      7-GID
         *
         *      Software only:
         *      bits 11-15      MCPCIA IRQ
         */
        const u_int irq = 
                (buspin - 1                         )   |
                ((device & 0x7)                 << 2)   |
                ((ccp->cc_mid - 4)              << 5)   |
                ((7 - ccp->cc_gid)              << 8)   |
                (mcpcia_irq                     << 11);
        alpha_pci_intr_handle_init(ihp, irq, 0);
        return (0);
}

static const char *
dec_kn300_intr_string(pci_chipset_tag_t const pc __unused,
    pci_intr_handle_t const ih, char * const buf, size_t const len)
{
        const u_int irq = alpha_pci_intr_handle_get_irq(&ih) & 0x3ff;

        snprintf(buf, len, "kn300 irq %u", irq);
        return buf;
}

static const struct evcnt *
dec_kn300_intr_evcnt(pci_chipset_tag_t const pc __unused,
    pci_intr_handle_t const ih)
{
        const u_int irq = alpha_pci_intr_handle_get_irq(&ih) & 0x3ff;

        return alpha_shared_intr_evcnt(kn300_pci_intr, irq);
}

static void *
dec_kn300_intr_establish(
        pci_chipset_tag_t const pc,
        pci_intr_handle_t const ih,
        int const level,
        int (*func)(void *),
        void *arg)
{
        struct mcpcia_config * const ccp = pc->pc_intr_v;
        void *cookie;
        const u_int ihv = alpha_pci_intr_handle_get_irq(&ih);
        const u_int irq = ihv & 0x3ff;
        const u_int flags = alpha_pci_intr_handle_get_flags(&ih);

        cookie = alpha_shared_intr_alloc_intrhand(kn300_pci_intr, irq,
            IST_LEVEL, level, flags, func, arg, "kn300");

        if (cookie == NULL)
                return NULL;

        mutex_enter(&cpu_lock);

        if (! alpha_shared_intr_link(kn300_pci_intr, cookie, "kn300")) {
                mutex_exit(&cpu_lock);
                alpha_shared_intr_free_intrhand(cookie);
                return NULL;
        }

        if (alpha_shared_intr_firstactive(kn300_pci_intr, irq)) {
                scb_set(MCPCIA_VEC_PCI + SCB_IDXTOVEC(irq), kn300_iointr, NULL);
                alpha_shared_intr_set_private(kn300_pci_intr, irq, ccp);
                savirqs[irq] = (ihv >> 11) & 0x1f;
                alpha_mb();
                kn300_enable_intr(ccp, savirqs[irq]);
        }

        mutex_exit(&cpu_lock);

        return cookie;
}

static void
dec_kn300_intr_disestablish(pci_chipset_tag_t const pc __unused,
    void * const cookie __unused)
{
        panic("dec_kn300_intr_disestablish not implemented");
}

static void
kn300_iointr(void * const arg __unused, unsigned long const vec)
{
        struct mcpcia_softc *mcp;
        u_long irq;

        irq = SCB_VECTOIDX(vec - MCPCIA_VEC_PCI);

        if (alpha_shared_intr_dispatch(kn300_pci_intr, irq)) {
                /*
                 * Any claim of an interrupt at this level is a hint to
                 * reset the stray interrupt count- elsewise a slow leak
                 * over time will cause this level to be shutdown.
                 */
                alpha_shared_intr_reset_strays(kn300_pci_intr, irq);
                return;
        }

        /*
         * If we haven't finished configuring yet, or there is no mcp
         * registered for this level yet, just return.
         */
        mcp = alpha_shared_intr_get_private(kn300_pci_intr, irq);
        if (mcp == NULL || mcp->mcpcia_cc == NULL)
                return;

        /*
         * We're getting an interrupt for a device we haven't enabled.
         * We had better not try and use -1 to find the right bit to disable.
         */
        if (savirqs[irq] == -1) {
                printf("kn300_iointr: stray interrupt vector 0x%lx\n", vec);
                return;
        }

        /*
         * Stray interrupt; disable the IRQ on the appropriate MCPCIA
         * if we've reached the limit.
         */
        alpha_shared_intr_stray(kn300_pci_intr, irq, "kn300");
        if (ALPHA_SHARED_INTR_DISABLE(kn300_pci_intr, irq) == 0)
                return;
        kn300_disable_intr(mcp->mcpcia_cc, savirqs[irq]);
}

static void
kn300_enable_intr(struct mcpcia_config * const ccp, int const irq)
{
        alpha_mb();
        REGVAL(MCPCIA_INT_MASK0(ccp)) |= (1 << irq);
        alpha_mb();
}

static void
kn300_disable_intr(struct mcpcia_config * const ccp, int const irq)
{
        alpha_mb();
        REGVAL(MCPCIA_INT_MASK0(ccp)) &= ~(1 << irq);
        alpha_mb();
}