/*      $OpenBSD: astro.c,v 1.19 2024/04/13 23:44:11 jsg Exp $  */

/*
 * Copyright (c) 2007 Mark Kettenis
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/device.h>
#include <sys/extent.h>
#include <sys/malloc.h>
#include <sys/mutex.h>
#include <sys/reboot.h>
#include <sys/tree.h>

#include <uvm/uvm_extern.h>

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

#include <hppa/dev/cpudevs.h>

struct astro_regs {
        u_int32_t       rid;
        u_int32_t       pad0000;
        u_int32_t       ioc_ctrl;
        u_int32_t       pad0008;
        u_int8_t        resv1[0x0300 - 0x0010];
        u_int64_t       lmmio_direct0_base;
        u_int64_t       lmmio_direct0_mask;
        u_int64_t       lmmio_direct0_route;
        u_int64_t       lmmio_direct1_base;
        u_int64_t       lmmio_direct1_mask;
        u_int64_t       lmmio_direct1_route;
        u_int64_t       lmmio_direct2_base;
        u_int64_t       lmmio_direct2_mask;
        u_int64_t       lmmio_direct2_route;
        u_int64_t       lmmio_direct3_base;
        u_int64_t       lmmio_direct3_mask;
        u_int64_t       lmmio_direct3_route;
        u_int64_t       lmmio_dist_base;
        u_int64_t       lmmio_dist_mask;
        u_int64_t       lmmio_dist_route;
        u_int64_t       gmmio_dist_base;
        u_int64_t       gmmio_dist_mask;
        u_int64_t       gmmio_dist_route;
        u_int64_t       ios_dist_base;
        u_int64_t       ios_dist_mask;
        u_int64_t       ios_dist_route;
        u_int8_t        resv2[0x03c0 - 0x03a8];
        u_int64_t       ios_direct_base;
        u_int64_t       ios_direct_mask;
        u_int64_t       ios_direct_route;
        u_int8_t        resv3[0x22000 - 0x03d8];
        u_int64_t       func_id;
        u_int64_t       func_class;
        u_int8_t        resv4[0x22040 - 0x22010];
        u_int64_t       rope_config;
        u_int8_t        resv5[0x22050 - 0x22048];
        u_int64_t       rope_debug;
        u_int8_t        resv6[0x22200 - 0x22058];
        u_int64_t       rope0_control;
        u_int64_t       rope1_control;
        u_int64_t       rope2_control;
        u_int64_t       rope3_control;
        u_int64_t       rope4_control;
        u_int64_t       rope5_control;
        u_int64_t       rope6_control;
        u_int64_t       rope7_control;
        u_int8_t        resv7[0x22300 - 0x22240];
        u_int32_t       tlb_ibase;
        u_int32_t       pad22300;
        u_int32_t       tlb_imask;
        u_int32_t       pad22308;
        u_int32_t       tlb_pcom;
        u_int32_t       pad22310;
        u_int32_t       tlb_tcnfg;
        u_int32_t       pad22318;
        u_int64_t       tlb_pdir_base;
};

#define ASTRO_IOC_CTRL_TE       0x0001  /* TOC Enable */
#define ASTRO_IOC_CTRL_CE       0x0002  /* Coalesce Enable */
#define ASTRO_IOC_CTRL_DE       0x0004  /* Dillon Enable */
#define ASTRO_IOC_CTRL_IE       0x0008  /* IOS Enable */
#define ASTRO_IOC_CTRL_OS       0x0010  /* Outbound Synchronous */
#define ASTRO_IOC_CTRL_IS       0x0020  /* Inbound Synchronous */
#define ASTRO_IOC_CTRL_RC       0x0040  /* Read Current Enable */
#define ASTRO_IOC_CTRL_L0       0x0080  /* 0-length Read Enable */
#define ASTRO_IOC_CTRL_RM       0x0100  /* Real Mode */
#define ASTRO_IOC_CTRL_NC       0x0200  /* Non-coherent Mode */
#define ASTRO_IOC_CTRL_ID       0x0400  /* Interrupt Disable */
#define ASTRO_IOC_CTRL_D4       0x0800  /* Disable 4-byte Coalescing */
#define ASTRO_IOC_CTRL_CC       0x1000  /* Increase Coalescing counter value */
#define ASTRO_IOC_CTRL_DD       0x2000  /* Disable distr. range coalescing */
#define ASTRO_IOC_CTRL_DC       0x4000  /* Disable the coalescing counter */

#define IOTTE_V         0x8000000000000000LL    /* Entry valid */
#define IOTTE_PAMASK    0x000000fffffff000LL
#define IOTTE_CI        0x00000000000000ffLL    /* Coherent index */

struct astro_softc {
        struct device sc_dv;

        bus_dma_tag_t sc_dmat;
        struct astro_regs volatile *sc_regs;
        u_int64_t *sc_pdir;

        char sc_dvmamapname[20];
        struct extent *sc_dvmamap;
        struct mutex sc_dvmamtx;

        struct hppa_bus_dma_tag sc_dmatag;
};

/*
 * per-map DVMA page table
 */
struct iommu_page_entry {
        SPLAY_ENTRY(iommu_page_entry) ipe_node;
        paddr_t ipe_pa;
        vaddr_t ipe_va;
        bus_addr_t ipe_dva;
};

struct iommu_page_map {
        SPLAY_HEAD(iommu_page_tree, iommu_page_entry) ipm_tree;
        int ipm_maxpage;        /* Size of allocated page map */
        int ipm_pagecnt;        /* Number of entries in use */
        struct iommu_page_entry ipm_map[1];
};

/*
 * per-map IOMMU state
 */
struct iommu_map_state {
        struct astro_softc *ims_sc;
        bus_addr_t ims_dvmastart;
        bus_size_t ims_dvmasize;
        struct extent_region ims_er;
        struct iommu_page_map ims_map;  /* map must be last (array at end) */
};

int     astro_match(struct device *, void *, void *);
void    astro_attach(struct device *, struct device *, void *);

const struct cfattach astro_ca = {
        sizeof(struct astro_softc), astro_match, astro_attach
};

struct cfdriver astro_cd = {
        NULL, "astro", DV_DULL
};

int     iommu_dvmamap_create(void *, bus_size_t, int, bus_size_t, bus_size_t,
            int, bus_dmamap_t *);
void    iommu_dvmamap_destroy(void *, bus_dmamap_t);
int     iommu_dvmamap_load(void *, bus_dmamap_t, void *, bus_size_t,
            struct proc *, int);
int     iommu_iomap_load_map(struct astro_softc *, bus_dmamap_t, int);
int     iommu_dvmamap_load_mbuf(void *, bus_dmamap_t, struct mbuf *, int);
int     iommu_dvmamap_load_uio(void *, bus_dmamap_t, struct uio *, int);
int     iommu_dvmamap_load_raw(void *, bus_dmamap_t, bus_dma_segment_t *,
            int, bus_size_t, int);
void    iommu_dvmamap_unload(void *, bus_dmamap_t);
void    iommu_dvmamap_sync(void *, bus_dmamap_t, bus_addr_t, bus_size_t, int);
int     iommu_dvmamem_alloc(void *, bus_size_t, bus_size_t, bus_size_t,
            bus_dma_segment_t *, int, int *, int);
void    iommu_dvmamem_free(void *, bus_dma_segment_t *, int);
int     iommu_dvmamem_map(void *, bus_dma_segment_t *, int, size_t,
            caddr_t *, int);
void    iommu_dvmamem_unmap(void *, caddr_t, size_t);
paddr_t iommu_dvmamem_mmap(void *, bus_dma_segment_t *, int, off_t, int, int);

void    iommu_enter(struct astro_softc *, bus_addr_t, paddr_t, vaddr_t, int);
void    iommu_remove(struct astro_softc *, bus_addr_t);

struct iommu_map_state *iommu_iomap_create(int);
void    iommu_iomap_destroy(struct iommu_map_state *);
int     iommu_iomap_insert_page(struct iommu_map_state *, vaddr_t, paddr_t);
bus_addr_t iommu_iomap_translate(struct iommu_map_state *, paddr_t);
void    iommu_iomap_clear_pages(struct iommu_map_state *);

const struct hppa_bus_dma_tag astro_dmat = {
        NULL,
        iommu_dvmamap_create, iommu_dvmamap_destroy,
        iommu_dvmamap_load, iommu_dvmamap_load_mbuf,
        iommu_dvmamap_load_uio, iommu_dvmamap_load_raw,
        iommu_dvmamap_unload, iommu_dvmamap_sync,

        iommu_dvmamem_alloc, iommu_dvmamem_free, iommu_dvmamem_map,
        iommu_dvmamem_unmap, iommu_dvmamem_mmap
};

int
astro_match(struct device *parent, void *cfdata, void *aux)   
{
        struct confargs *ca = aux;

        /* Astro is a U-Turn variant. */
        if (ca->ca_type.iodc_type != HPPA_TYPE_IOA ||
            ca->ca_type.iodc_sv_model != HPPA_IOA_UTURN)
                return 0;

        if (ca->ca_type.iodc_model == 0x58 &&
            ca->ca_type.iodc_revision >= 0x20)
                return 1;

        return 0;
}

void
astro_attach(struct device *parent, struct device *self, void *aux)
{
        struct confargs *ca = aux, nca;
        struct astro_softc *sc = (struct astro_softc *)self;
        volatile struct astro_regs *r;
        bus_space_handle_t ioh;
        u_int32_t rid, ioc_ctrl;
        psize_t size;
        vaddr_t va;
        paddr_t pa;
        struct vm_page *m;
        struct pglist mlist;
        int iova_bits;

        sc->sc_dmat = ca->ca_dmatag;
        if (bus_space_map(ca->ca_iot, ca->ca_hpa, sizeof(struct astro_regs),
            0, &ioh)) {
                printf(": can't map IO space\n");
                return;
        }
        sc->sc_regs = r = (struct astro_regs *)ca->ca_hpa;

        rid = letoh32(r->rid);
        printf(": Astro rev %d.%d\n", (rid & 7) + 1, (rid >> 3) & 3);

        ioc_ctrl = letoh32(r->ioc_ctrl);
        ioc_ctrl &= ~ASTRO_IOC_CTRL_CE;
        ioc_ctrl &= ~ASTRO_IOC_CTRL_RM;
        ioc_ctrl &= ~ASTRO_IOC_CTRL_NC;
        r->ioc_ctrl = htole32(ioc_ctrl);

        /*
         * Setup the iommu.
         */

        /* XXX This gives us 256MB of iova space. */
        iova_bits = 28;

        r->tlb_ibase = htole32(0);
        r->tlb_imask = htole32(0xffffffff << iova_bits);

        /* Page size is 4K. */
        r->tlb_tcnfg = htole32(0);

        /* Flush TLB. */
        r->tlb_pcom = htole32(31);

        /*
         * Allocate memory for I/O pagetables.  They need to be physically
         * contiguous.
         */

        size = (1 << (iova_bits - PAGE_SHIFT)) * sizeof(u_int64_t);
        TAILQ_INIT(&mlist);
        if (uvm_pglistalloc(size, 0, -1, PAGE_SIZE, 0, &mlist,
            1, UVM_PLA_NOWAIT) != 0)
                panic("astrottach: no memory");

        va = (vaddr_t)km_alloc(size, &kv_any, &kp_none, &kd_nowait);
        if (va == 0)
                panic("astroattach: no memory");
        sc->sc_pdir = (u_int64_t *)va;

        m = TAILQ_FIRST(&mlist);
        r->tlb_pdir_base = htole64(VM_PAGE_TO_PHYS(m));

        /* Map the pages. */
        for (; m != NULL; m = TAILQ_NEXT(m, pageq)) {
                pa = VM_PAGE_TO_PHYS(m);
                pmap_enter(pmap_kernel(), va, pa,
                    PROT_READ | PROT_WRITE, PMAP_WIRED);
                va += PAGE_SIZE;
        }
        pmap_update(pmap_kernel());
        memset(sc->sc_pdir, 0, size);

        /*
         * The PDC might have set up some devices to do DMA.  It will do
         * this for the onboard USB controller if an USB keyboard is used
         * for console input.  In that case, bad things will happen if we
         * enable iova space.  So reset the PDC devices before we do that.
         * Don't do this if we're using a serial console though, since it
         * will stop working if we do.  This is fine since the serial port
         * doesn't do DMA.
         */
        if (PAGE0->mem_cons.pz_class != PCL_DUPLEX)
                pdc_call((iodcio_t)pdc, 0, PDC_IO, PDC_IO_RESET_DEVICES);

        /* Enable iova space. */
        r->tlb_ibase = htole32(1);

        /*
         * Now all the hardware's working we need to allocate a dvma map.
         */
        snprintf(sc->sc_dvmamapname, sizeof(sc->sc_dvmamapname),
            "%s_dvma", sc->sc_dv.dv_xname);
        sc->sc_dvmamap = extent_create(sc->sc_dvmamapname, 0, (1 << iova_bits),
            M_DEVBUF, NULL, 0, EX_NOWAIT | EX_NOCOALESCE);
        KASSERT(sc->sc_dvmamap);
        mtx_init(&sc->sc_dvmamtx, IPL_HIGH);

        sc->sc_dmatag = astro_dmat;
        sc->sc_dmatag._cookie = sc;

        nca = *ca;      /* clone from us */
        nca.ca_hpamask = HPPA_IOBEGIN;
        nca.ca_dmatag = &sc->sc_dmatag;
        pdc_scanbus(self, &nca, MAXMODBUS, 0, 0);
}

int
iommu_dvmamap_create(void *v, bus_size_t size, int nsegments,
    bus_size_t maxsegsz, bus_size_t boundary, int flags, bus_dmamap_t *dmamap)
{
        struct astro_softc *sc = v;
        bus_dmamap_t map;
        struct iommu_map_state *ims;
        int error;

        error = bus_dmamap_create(sc->sc_dmat, size, nsegments, maxsegsz,
            boundary, flags, &map);
        if (error)
                return (error);

        ims = iommu_iomap_create(atop(round_page(size)));
        if (ims == NULL) {
                bus_dmamap_destroy(sc->sc_dmat, map);
                return (ENOMEM);
        }

        ims->ims_sc = sc;
        map->_dm_cookie = ims;
        *dmamap = map;

        return (0);
}

void
iommu_dvmamap_destroy(void *v, bus_dmamap_t map)
{
        struct astro_softc *sc = v;

        /*
         * The specification (man page) requires a loaded
         * map to be unloaded before it is destroyed.
         */
        if (map->dm_nsegs)
                iommu_dvmamap_unload(sc, map);

        if (map->_dm_cookie)
                iommu_iomap_destroy(map->_dm_cookie);
        map->_dm_cookie = NULL;

        bus_dmamap_destroy(sc->sc_dmat, map);
}

int
iommu_iomap_load_map(struct astro_softc *sc, bus_dmamap_t map, int flags)
{
        struct iommu_map_state *ims = map->_dm_cookie;
        struct iommu_page_map *ipm = &ims->ims_map;
        struct iommu_page_entry *e;
        int err, seg;
        paddr_t pa, paend;
        vaddr_t va;
        bus_size_t sgsize;
        bus_size_t align, boundary;
        u_long dvmaddr;
        bus_addr_t dva;
        int i;

        /* XXX */
        boundary = map->_dm_boundary;
        align = PAGE_SIZE;

        iommu_iomap_clear_pages(ims);

        for (seg = 0; seg < map->dm_nsegs; seg++) {
                struct hppa_bus_dma_segment *ds = &map->dm_segs[seg];

                paend = round_page(ds->ds_addr + ds->ds_len);
                for (pa = trunc_page(ds->ds_addr), va = trunc_page(ds->_ds_va);
                     pa < paend; pa += PAGE_SIZE, va += PAGE_SIZE) {
                        err = iommu_iomap_insert_page(ims, va, pa);
                        if (err) {
                                printf("iomap insert error: %d for "
                                    "va 0x%lx pa 0x%lx\n", err, va, pa);
                                bus_dmamap_unload(sc->sc_dmat, map);
                                iommu_iomap_clear_pages(ims);
                        }
                }
        }

        sgsize = ims->ims_map.ipm_pagecnt * PAGE_SIZE;
        mtx_enter(&sc->sc_dvmamtx);
        err = extent_alloc_with_descr(sc->sc_dvmamap, sgsize, align, 0,
            boundary, EX_NOWAIT | EX_BOUNDZERO, &ims->ims_er, &dvmaddr);
        mtx_leave(&sc->sc_dvmamtx);
        if (err)
                return (err);

        ims->ims_dvmastart = dvmaddr;
        ims->ims_dvmasize = sgsize;

        dva = dvmaddr;
        for (i = 0, e = ipm->ipm_map; i < ipm->ipm_pagecnt; ++i, ++e) {
                e->ipe_dva = dva;
                iommu_enter(sc, e->ipe_dva, e->ipe_pa, e->ipe_va, flags);
                dva += PAGE_SIZE;
        }

        for (seg = 0; seg < map->dm_nsegs; seg++) {
                struct hppa_bus_dma_segment *ds = &map->dm_segs[seg];
                ds->ds_addr = iommu_iomap_translate(ims, ds->ds_addr);
        }

        return (0);
}

int
iommu_dvmamap_load(void *v, bus_dmamap_t map, void *addr, bus_size_t size,
    struct proc *p, int flags)
{
        struct astro_softc *sc = v;
        int err;

        err = bus_dmamap_load(sc->sc_dmat, map, addr, size, p, flags);
        if (err)
                return (err);

        return iommu_iomap_load_map(sc, map, flags);
}

int
iommu_dvmamap_load_mbuf(void *v, bus_dmamap_t map, struct mbuf *m, int flags)
{
        struct astro_softc *sc = v;
        int err;

        err = bus_dmamap_load_mbuf(sc->sc_dmat, map, m, flags);
        if (err)
                return (err);

        return iommu_iomap_load_map(sc, map, flags);
}

int
iommu_dvmamap_load_uio(void *v, bus_dmamap_t map, struct uio *uio, int flags)
{
        struct astro_softc *sc = v;

        printf("load_uio\n");

        return (bus_dmamap_load_uio(sc->sc_dmat, map, uio, flags));
}

int
iommu_dvmamap_load_raw(void *v, bus_dmamap_t map, bus_dma_segment_t *segs,
    int nsegs, bus_size_t size, int flags)
{
        struct astro_softc *sc = v;

        printf("load_raw\n");

        return (bus_dmamap_load_raw(sc->sc_dmat, map, segs, nsegs, size, flags));
}

void
iommu_dvmamap_unload(void *v, bus_dmamap_t map)
{
        struct astro_softc *sc = v;
        struct iommu_map_state *ims = map->_dm_cookie;
        struct iommu_page_map *ipm = &ims->ims_map;
        struct iommu_page_entry *e;
        int err, i;

        /* Remove the IOMMU entries. */
        for (i = 0, e = ipm->ipm_map; i < ipm->ipm_pagecnt; ++i, ++e)
                iommu_remove(sc, e->ipe_dva);

        /* Clear the iomap. */
        iommu_iomap_clear_pages(ims);

        bus_dmamap_unload(sc->sc_dmat, map);

        mtx_enter(&sc->sc_dvmamtx);
        err = extent_free(sc->sc_dvmamap, ims->ims_dvmastart,
            ims->ims_dvmasize, EX_NOWAIT);
        ims->ims_dvmastart = 0;
        ims->ims_dvmasize = 0;
        mtx_leave(&sc->sc_dvmamtx);
        if (err)
                printf("warning: %ld of DVMA space lost\n", ims->ims_dvmasize);
}

void
iommu_dvmamap_sync(void *v, bus_dmamap_t map, bus_addr_t off,
    bus_size_t len, int ops)
{
        /* Nothing to do; DMA is cache-coherent. */
}

int
iommu_dvmamem_alloc(void *v, bus_size_t size, bus_size_t alignment,
    bus_size_t boundary, bus_dma_segment_t *segs,
    int nsegs, int *rsegs, int flags)
{
        struct astro_softc *sc = v;

        return (bus_dmamem_alloc(sc->sc_dmat, size, alignment, boundary,
            segs, nsegs, rsegs, flags));
}

void
iommu_dvmamem_free(void *v, bus_dma_segment_t *segs, int nsegs)
{
        struct astro_softc *sc = v;

        bus_dmamem_free(sc->sc_dmat, segs, nsegs);
}

int
iommu_dvmamem_map(void *v, bus_dma_segment_t *segs, int nsegs, size_t size,
    caddr_t *kvap, int flags)
{
        struct astro_softc *sc = v;

        return (bus_dmamem_map(sc->sc_dmat, segs, nsegs, size, kvap, flags));
}

void
iommu_dvmamem_unmap(void *v, caddr_t kva, size_t size)
{
        struct astro_softc *sc = v;

        bus_dmamem_unmap(sc->sc_dmat, kva, size);
}

paddr_t
iommu_dvmamem_mmap(void *v, bus_dma_segment_t *segs, int nsegs, off_t off,
    int prot, int flags)
{
        struct astro_softc *sc = v;

        return (bus_dmamem_mmap(sc->sc_dmat, segs, nsegs, off, prot, flags));
}

/*
 * Utility function used by splay tree to order page entries by pa.
 */
static inline int
iomap_compare(struct iommu_page_entry *a, struct iommu_page_entry *b)
{
        return ((a->ipe_pa > b->ipe_pa) ? 1 :
                (a->ipe_pa < b->ipe_pa) ? -1 : 0);
}

SPLAY_PROTOTYPE(iommu_page_tree, iommu_page_entry, ipe_node, iomap_compare);

SPLAY_GENERATE(iommu_page_tree, iommu_page_entry, ipe_node, iomap_compare);

/*
 * Create a new iomap.
 */
struct iommu_map_state *
iommu_iomap_create(int n)
{
        struct iommu_map_state *ims;

        /* Safety for heavily fragmented data, such as mbufs */
        n += 4;
        if (n < 16)
                n = 16;

        ims = malloc(sizeof(*ims) + (n - 1) * sizeof(ims->ims_map.ipm_map[0]),
            M_DEVBUF, M_NOWAIT | M_ZERO);
        if (ims == NULL)
                return (NULL);

        /* Initialize the map. */
        ims->ims_map.ipm_maxpage = n;
        SPLAY_INIT(&ims->ims_map.ipm_tree);

        return (ims);
}

/*
 * Destroy an iomap.
 */
void
iommu_iomap_destroy(struct iommu_map_state *ims)
{
#ifdef DIAGNOSTIC
        if (ims->ims_map.ipm_pagecnt > 0)
                printf("iommu_iomap_destroy: %d page entries in use\n",
                    ims->ims_map.ipm_pagecnt);
#endif

        free(ims, M_DEVBUF, 0);
}

/*
 * Insert a pa entry in the iomap.
 */
int
iommu_iomap_insert_page(struct iommu_map_state *ims, vaddr_t va, paddr_t pa)
{
        struct iommu_page_map *ipm = &ims->ims_map;
        struct iommu_page_entry *e;

        if (ipm->ipm_pagecnt >= ipm->ipm_maxpage) {
                struct iommu_page_entry ipe;

                ipe.ipe_pa = pa;
                if (SPLAY_FIND(iommu_page_tree, &ipm->ipm_tree, &ipe))
                        return (0);

                return (ENOMEM);
        }

        e = &ipm->ipm_map[ipm->ipm_pagecnt];

        e->ipe_pa = pa;
        e->ipe_va = va;
        e->ipe_dva = 0;

        e = SPLAY_INSERT(iommu_page_tree, &ipm->ipm_tree, e);

        /* Duplicates are okay, but only count them once. */
        if (e)
                return (0);

        ++ipm->ipm_pagecnt;

        return (0);
}

/*
 * Translate a physical address (pa) into a DVMA address.
 */
bus_addr_t
iommu_iomap_translate(struct iommu_map_state *ims, paddr_t pa)
{
        struct iommu_page_map *ipm = &ims->ims_map;
        struct iommu_page_entry *e;
        struct iommu_page_entry pe;
        paddr_t offset = pa & PAGE_MASK;

        pe.ipe_pa = trunc_page(pa);

        e = SPLAY_FIND(iommu_page_tree, &ipm->ipm_tree, &pe);

        if (e == NULL) {
                panic("couldn't find pa %lx", pa);
                return 0;
        }

        return (e->ipe_dva | offset);
}

/*
 * Clear the iomap table and tree.
 */
void
iommu_iomap_clear_pages(struct iommu_map_state *ims)
{
        ims->ims_map.ipm_pagecnt = 0;
        SPLAY_INIT(&ims->ims_map.ipm_tree);
}

/*
 * Add an entry to the IOMMU table.
 */
void
iommu_enter(struct astro_softc *sc, bus_addr_t dva, paddr_t pa, vaddr_t va,
    int flags)
{
        volatile u_int64_t *tte_ptr = &sc->sc_pdir[dva >> PAGE_SHIFT];
        u_int64_t tte;
        u_int32_t ci;

#ifdef DEBUG
        printf("iommu_enter dva %lx, pa %lx, va %lx\n", dva, pa, va);
#endif

#ifdef DIAGNOSTIC
        tte = letoh64(*tte_ptr);

        if (tte & IOTTE_V) {
                printf("Overwriting valid tte entry (dva %lx pa %lx "
                    "&tte %p tte %llx)\n", dva, pa, tte_ptr, tte);
                extent_print(sc->sc_dvmamap);
                panic("IOMMU overwrite");
        }
#endif

        mtsp(HPPA_SID_KERNEL, 1);
        __asm volatile("lci 0(%%sr1, %1), %0" : "=r" (ci) : "r" (va));

        tte = (pa & IOTTE_PAMASK) | ((ci >> 12) & IOTTE_CI);
        tte |= IOTTE_V;

        *tte_ptr = htole64(tte);
        __asm volatile("fdc 0(%%sr1, %0)\n\tsync" : : "r" (tte_ptr));
}

/*
 * Remove an entry from the IOMMU table.
 */
void
iommu_remove(struct astro_softc *sc, bus_addr_t dva)
{
        volatile struct astro_regs *r = sc->sc_regs;
        u_int64_t *tte_ptr = &sc->sc_pdir[dva >> PAGE_SHIFT];
        u_int64_t tte;

#ifdef DIAGNOSTIC
        if (dva != trunc_page(dva)) {
                printf("iommu_remove: unaligned dva: %lx\n", dva);
                dva = trunc_page(dva);
        }
#endif

        tte = letoh64(*tte_ptr);

#ifdef DIAGNOSTIC
        if ((tte & IOTTE_V) == 0) {
                printf("Removing invalid tte entry (dva %lx &tte %p "
                    "tte %llx)\n", dva, tte_ptr, tte);
                extent_print(sc->sc_dvmamap);
                panic("IOMMU remove overwrite");
        }
#endif

        *tte_ptr = htole64(tte & ~IOTTE_V);

        /* Flush IOMMU. */
        r->tlb_pcom = htole32(dva | PAGE_SHIFT);
}