/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2008 Semihalf, Grzegorz Bernacki
 * Copyright (c) 2006 Peter Wemm
 *
 * 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, 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.
 *
 * 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.
 *
 * From: FreeBSD: src/lib/libkvm/kvm_minidump_i386.c,v 1.2 2006/06/05 08:51:14
 */

#include <sys/cdefs.h>
/*
 * ARM machine dependent routines for kvm and minidumps.
 */

#include <sys/endian.h>
#include <sys/param.h>
#include <vm/vm.h>
#include <kvm.h>
#include <limits.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include "../../sys/arm/include/minidump.h"

#include "kvm_private.h"
#include "kvm_arm.h"

#define arm_round_page(x)       roundup2((kvaddr_t)(x), ARM_PAGE_SIZE)

struct vmstate {
        struct          minidumphdr hdr;
        unsigned char   ei_data;
};

static arm_pt_entry_t
_arm_pte_get(kvm_t *kd, u_long pteindex)
{
        arm_pt_entry_t *pte = _kvm_pmap_get(kd, pteindex, sizeof(*pte));

        return _kvm32toh(kd, *pte);
}

static int
_arm_minidump_probe(kvm_t *kd)
{

        return (_kvm_probe_elf_kernel(kd, ELFCLASS32, EM_ARM) &&
            _kvm_is_minidump(kd));
}

static void
_arm_minidump_freevtop(kvm_t *kd)
{
        struct vmstate *vm = kd->vmst;

        free(vm);
        kd->vmst = NULL;
}

static int
_arm_minidump_initvtop(kvm_t *kd)
{
        struct vmstate *vmst;
        off_t off, dump_avail_off, sparse_off;

        vmst = _kvm_malloc(kd, sizeof(*vmst));
        if (vmst == NULL) {
                _kvm_err(kd, kd->program, "cannot allocate vm");
                return (-1);
        }

        kd->vmst = vmst;

        if (pread(kd->pmfd, &vmst->hdr,
            sizeof(vmst->hdr), 0) != sizeof(vmst->hdr)) {
                _kvm_err(kd, kd->program, "cannot read dump header");
                return (-1);
        }

        if (strncmp(MINIDUMP_MAGIC, vmst->hdr.magic,
            sizeof(vmst->hdr.magic)) != 0) {
                _kvm_err(kd, kd->program, "not a minidump for this platform");
                return (-1);
        }
        vmst->hdr.version = _kvm32toh(kd, vmst->hdr.version);
        if (vmst->hdr.version != MINIDUMP_VERSION && vmst->hdr.version != 1) {
                _kvm_err(kd, kd->program, "wrong minidump version. "
                    "Expected %d got %d", MINIDUMP_VERSION, vmst->hdr.version);
                return (-1);
        }
        vmst->hdr.msgbufsize = _kvm32toh(kd, vmst->hdr.msgbufsize);
        vmst->hdr.bitmapsize = _kvm32toh(kd, vmst->hdr.bitmapsize);
        vmst->hdr.ptesize = _kvm32toh(kd, vmst->hdr.ptesize);
        vmst->hdr.kernbase = _kvm32toh(kd, vmst->hdr.kernbase);
        vmst->hdr.arch = _kvm32toh(kd, vmst->hdr.arch);
        vmst->hdr.mmuformat = _kvm32toh(kd, vmst->hdr.mmuformat);
        if (vmst->hdr.mmuformat == MINIDUMP_MMU_FORMAT_UNKNOWN) {
                /* This is a safe default as 1K pages are not used. */
                vmst->hdr.mmuformat = MINIDUMP_MMU_FORMAT_V6;
        }
        vmst->hdr.dumpavailsize = vmst->hdr.version == MINIDUMP_VERSION ?
            _kvm32toh(kd, vmst->hdr.dumpavailsize) : 0;

        /* Skip header and msgbuf */
        dump_avail_off = ARM_PAGE_SIZE + arm_round_page(vmst->hdr.msgbufsize);

        /* Skip dump_avail */
        off = dump_avail_off + arm_round_page(vmst->hdr.dumpavailsize);

        sparse_off = off + arm_round_page(vmst->hdr.bitmapsize) +
            arm_round_page(vmst->hdr.ptesize);
        if (_kvm_pt_init(kd, vmst->hdr.dumpavailsize, dump_avail_off,
            vmst->hdr.bitmapsize, off, sparse_off, ARM_PAGE_SIZE) == -1) {
                return (-1);
        }
        off += arm_round_page(vmst->hdr.bitmapsize);

        if (_kvm_pmap_init(kd, vmst->hdr.ptesize, off) == -1) {
                return (-1);
        }
        off += arm_round_page(vmst->hdr.ptesize);

        return (0);
}

static int
_arm_minidump_kvatop(kvm_t *kd, kvaddr_t va, off_t *pa)
{
        struct vmstate *vm;
        arm_pt_entry_t pte;
        arm_physaddr_t offset, a;
        kvaddr_t pteindex;
        off_t ofs;

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

        vm = kd->vmst;

        if (va >= vm->hdr.kernbase) {
                pteindex = (va - vm->hdr.kernbase) >> ARM_PAGE_SHIFT;
                if (pteindex >= vm->hdr.ptesize / sizeof(pte))
                        goto invalid;
                pte = _arm_pte_get(kd, pteindex);
                if ((pte & ARM_L2_TYPE_MASK) == ARM_L2_TYPE_INV) {
                        _kvm_err(kd, kd->program,
                            "_arm_minidump_kvatop: pte not valid");
                        goto invalid;
                }
                if ((pte & ARM_L2_TYPE_MASK) == ARM_L2_TYPE_L) {
                        /* 64K page -> convert to be like 4K page */
                        offset = va & ARM_L2_S_OFFSET;
                        a = (pte & ARM_L2_L_FRAME) +
                            (va & ARM_L2_L_OFFSET & ARM_L2_S_FRAME);
                } else {
                        if (kd->vmst->hdr.mmuformat == MINIDUMP_MMU_FORMAT_V4 &&
                            (pte & ARM_L2_TYPE_MASK) == ARM_L2_TYPE_T) {
                                _kvm_err(kd, kd->program,
                                    "_arm_minidump_kvatop: pte not supported");
                                goto invalid;
                        }
                        /* 4K page */
                        offset = va & ARM_L2_S_OFFSET;
                        a = pte & ARM_L2_S_FRAME;
                }

                ofs = _kvm_pt_find(kd, a, ARM_PAGE_SIZE);
                if (ofs == -1) {
                        _kvm_err(kd, kd->program, "_arm_minidump_kvatop: "
                            "physical address 0x%jx not in minidump",
                            (uintmax_t)a);
                        goto invalid;
                }

                *pa = ofs + offset;
                return (ARM_PAGE_SIZE - offset);
        } else
                _kvm_err(kd, kd->program, "_arm_minidump_kvatop: virtual "
                    "address 0x%jx not minidumped", (uintmax_t)va);

invalid:
        _kvm_err(kd, 0, "invalid address (0x%jx)", (uintmax_t)va);
        return (0);
}

static vm_prot_t
_arm_entry_to_prot(kvm_t *kd, arm_pt_entry_t pte)
{
        struct vmstate *vm = kd->vmst;
        vm_prot_t prot = VM_PROT_READ;

        /* Source: arm/arm/pmap-v4.c:pmap_fault_fixup() */
        if (vm->hdr.mmuformat == MINIDUMP_MMU_FORMAT_V4) {
                if (pte & ARM_L2_S_PROT_W)
                        prot |= VM_PROT_WRITE;
                return prot;
        }

        /* Source: arm/arm/pmap-v6.c:pmap_protect() */
        if ((pte & ARM_PTE2_RO) == 0)
                prot |= VM_PROT_WRITE;
        if ((pte & ARM_PTE2_NX) == 0)
                prot |= VM_PROT_EXECUTE;
        return prot;
}

static int
_arm_minidump_walk_pages(kvm_t *kd, kvm_walk_pages_cb_t *cb, void *arg)
{
        struct vmstate *vm = kd->vmst;
        u_long nptes = vm->hdr.ptesize / sizeof(arm_pt_entry_t);
        u_long dva, pa, pteindex, va;

        for (pteindex = 0; pteindex < nptes; pteindex++) {
                arm_pt_entry_t pte = _arm_pte_get(kd, pteindex);

                if ((pte & ARM_L2_TYPE_MASK) == ARM_L2_TYPE_INV)
                        continue;

                va = vm->hdr.kernbase + (pteindex << ARM_PAGE_SHIFT);
                if ((pte & ARM_L2_TYPE_MASK) == ARM_L2_TYPE_L) {
                        /* 64K page */
                        pa = (pte & ARM_L2_L_FRAME) +
                            (va & ARM_L2_L_OFFSET & ARM_L2_S_FRAME);
                } else {
                        if (vm->hdr.mmuformat == MINIDUMP_MMU_FORMAT_V4 &&
                            (pte & ARM_L2_TYPE_MASK) == ARM_L2_TYPE_T) {
                                continue;
                        }
                        /* 4K page */
                        pa = pte & ARM_L2_S_FRAME;
                }

                dva = 0; /* no direct map on this platform */
                if (!_kvm_visit_cb(kd, cb, arg, pa, va, dva,
                    _arm_entry_to_prot(kd, pte), ARM_PAGE_SIZE, 0))
                        return (0);
        }
        return (1);
}

static struct kvm_arch kvm_arm_minidump = {
        .ka_probe = _arm_minidump_probe,
        .ka_initvtop = _arm_minidump_initvtop,
        .ka_freevtop = _arm_minidump_freevtop,
        .ka_kvatop = _arm_minidump_kvatop,
        .ka_native = _arm_native,
        .ka_walk_pages = _arm_minidump_walk_pages,
};

KVM_ARCH(kvm_arm_minidump);