/*      $OpenBSD: kvm_sh.c,v 1.9 2021/12/01 21:45:19 deraadt Exp $      */

/*
 * Copyright (c) 2007 Miodrag Vallat.
 *
 * 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, this permission notice, and the disclaimer below
 * 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/types.h>
#include <sys/kcore.h>

#include <unistd.h>
#include <stdlib.h>
#include <nlist.h>
#include <kvm.h>

#include <db.h>

#include "kvm_private.h"

#include <machine/cpu.h>
#include <machine/kcore.h>
#include <machine/pte.h>
#include <machine/vmparam.h>

void
_kvm_freevtop(kvm_t *kd)
{
}

int
_kvm_initvtop(kvm_t *kd)
{
        return (0);
}

/*
 * Translate a kernel virtual address to a physical address by walking
 * the kernel page tables.
 */

/* Stolen from sys/arch/sh/include/pmap.h we can't really include */
#define __PMAP_PTP_N            512     /* # of page table page maps 2GB. */
/* Stolen from sys/arch/sh/sh/pmap.c */
#define __PMAP_PTP_SHIFT        22
#define __PMAP_PTP_PG_N         (kd->nbpg / sizeof(pt_entry_t))
#define __PMAP_PTP_INDEX(va)    (((va) >> __PMAP_PTP_SHIFT) & (__PMAP_PTP_N - 1))
#define __PMAP_PTP_OFSET(va)    ((va / kd->nbpg) & (__PMAP_PTP_PG_N - 1))

int
_kvm_kvatop(kvm_t *kd, u_long va, paddr_t *pa)
{
        cpu_kcore_hdr_t *h = kd->cpu_data;
        u_int l1idx, l2idx;
        vaddr_t l2va;
        pt_entry_t l1pte, l2pte;
        off_t pteoffset;

        if (ISALIVE(kd)) {
                _kvm_err(kd, 0, "vatop called in live kernel!");
                return (0);
        }

        /*
         * P1 and P2 segments addresses are trivial.
         */
        if (va >= SH3_P1SEG_BASE && va <= SH3_P1SEG_END) {
                *pa = SH3_P1SEG_TO_PHYS(va);
                return (int)((vaddr_t)SH3_P1SEG_END + 1 - va);
        }
        if (va >= SH3_P2SEG_BASE && va <= SH3_P2SEG_END) {
                *pa = SH3_P2SEG_TO_PHYS(va);
                return (int)((vaddr_t)SH3_P2SEG_END + 1 - va);
        }

        /*
         * P3 segment addresses need kernel page table walk.
         */
        if (va >= SH3_P3SEG_BASE && va < SH3_P3SEG_END) {
                l1idx = __PMAP_PTP_INDEX(va - VM_MIN_KERNEL_ADDRESS);
                l2idx = __PMAP_PTP_OFSET(va);

                /* read level 1 pte */
                pteoffset = h->kcore_kptp + sizeof(pt_entry_t) * l1idx;
                if (_kvm_pread(kd, kd->pmfd, (char *)&l1pte, sizeof(l1pte),
                    _kvm_pa2off(kd, pteoffset)) != sizeof(l1pte)) {
                        _kvm_syserr(kd, 0, "could not read level 1 pte");
                        goto bad;
                }

                /* check pte for validity */
                if ((l1pte & PG_V) == 0) {
                        _kvm_err(kd, 0, "invalid level 1 pte: no valid bit");
                        goto bad;
                }

                l2va = l1pte & PG_PPN;
                if (l2va < SH3_P1SEG_BASE || l2va > SH3_P1SEG_END) {
                        _kvm_err(kd, 0, "invalid level 1 pte: out of P1");
                        goto bad;
                }

                /* read level 2 pte */
                pteoffset = SH3_P1SEG_TO_PHYS(l2va) +
                    sizeof(pt_entry_t) * l2idx;
                if (_kvm_pread(kd, kd->pmfd, (char *)&l2pte, sizeof(l2pte),
                    _kvm_pa2off(kd, pteoffset)) != sizeof(l2pte)) {
                        _kvm_syserr(kd, 0, "could not read level 2 pte");
                        goto bad;
                }

                /* check pte for validity */
                if ((l2pte & PG_V) == 0) {
                        _kvm_err(kd, 0, "invalid level 2 pte: no valid bit");
                        goto bad;
                }

                *pa = (l2pte & PG_PPN) | (va & (kd->nbpg - 1));
                return (kd->nbpg - (va & (kd->nbpg - 1)));
        }

        /*
         * All other addresses are incorrect.
         */
        _kvm_err(kd, 0, "not a kernel virtual address");
bad:
        *pa = (paddr_t)-1;
        return (0);
}

/*
 * Translate a physical address to a file offset in the crash dump.
 */
off_t
_kvm_pa2off(kvm_t *kd, paddr_t pa)
{
        cpu_kcore_hdr_t *h = kd->cpu_data;
        phys_ram_seg_t *seg = h->kcore_segs;
        off_t off = kd->dump_off;
        u_int i;

        for (i = h->kcore_nsegs; i != 0; i--) {
                if (pa >= seg->start && pa < seg->start + seg->size)
                        return (off + (pa - seg->start));
                off += seg->size;
        }

        _kvm_err(kd, 0, "physical address out of the image (%lx)", pa);
        return (0);
}