/*-
 * 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_amd64.c r261799
 */

#include <sys/cdefs.h>
/*
 * ARM64 (AArch64) machine dependent routines for kvm and minidumps.
 */

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

#include "../../sys/arm64/include/minidump.h"

#include <limits.h>

#include "kvm_private.h"
#include "kvm_aarch64.h"

#define aarch64_round_page(x, size)     roundup2((kvaddr_t)(x), size)
#define aarch64_trunc_page(x, size)     rounddown2((kvaddr_t)(x), size)

struct vmstate {
        struct minidumphdr hdr;
        size_t page_size;
        u_int l3_shift;
};

static aarch64_pte_t
_aarch64_pte_get(kvm_t *kd, u_long pteindex)
{
        aarch64_pte_t *pte = _kvm_pmap_get(kd, pteindex, sizeof(*pte));

        return le64toh(*pte);
}

static int
_aarch64_minidump_probe(kvm_t *kd)
{

        return (_kvm_probe_elf_kernel(kd, ELFCLASS64, EM_AARCH64) &&
            _kvm_is_minidump(kd));
}

static void
_aarch64_minidump_freevtop(kvm_t *kd)
{
        struct vmstate *vm = kd->vmst;

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

static int
_aarch64_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 = le32toh(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 = le32toh(vmst->hdr.msgbufsize);
        vmst->hdr.bitmapsize = le32toh(vmst->hdr.bitmapsize);
        vmst->hdr.pmapsize = le32toh(vmst->hdr.pmapsize);
        vmst->hdr.kernbase = le64toh(vmst->hdr.kernbase);
        vmst->hdr.dmapphys = le64toh(vmst->hdr.dmapphys);
        vmst->hdr.dmapbase = le64toh(vmst->hdr.dmapbase);
        vmst->hdr.dmapend = le64toh(vmst->hdr.dmapend);
        /* dumpavailsize added in version 2 */
        if (vmst->hdr.version >= 2) {
                vmst->hdr.dumpavailsize = le32toh(vmst->hdr.dumpavailsize);
        } else {
                vmst->hdr.dumpavailsize = 0;
        }
        /* flags added in version 3 */
        if (vmst->hdr.version >= 3) {
                vmst->hdr.flags = le32toh(vmst->hdr.flags);
        } else {
                vmst->hdr.flags = MINIDUMP_FLAG_PS_4K;
        }

        switch (vmst->hdr.flags & MINIDUMP_FLAG_PS_MASK) {
        case MINIDUMP_FLAG_PS_4K:
                vmst->page_size = AARCH64_PAGE_SIZE_4K;
                vmst->l3_shift = AARCH64_L3_SHIFT_4K;
                break;
        case MINIDUMP_FLAG_PS_16K:
                vmst->page_size = AARCH64_PAGE_SIZE_16K;
                vmst->l3_shift = AARCH64_L3_SHIFT_16K;
                break;
        default:
                _kvm_err(kd, kd->program, "unknown page size flag %x",
                    vmst->hdr.flags & MINIDUMP_FLAG_PS_MASK);
                return (-1);
        }

        /* Skip header and msgbuf */
        dump_avail_off = vmst->page_size +
            aarch64_round_page(vmst->hdr.msgbufsize, vmst->page_size);

        /* Skip dump_avail */
        off = dump_avail_off +
            aarch64_round_page(vmst->hdr.dumpavailsize, vmst->page_size);

        /* build physical address lookup table for sparse pages */
        sparse_off = off +
            aarch64_round_page(vmst->hdr.bitmapsize, vmst->page_size) +
            aarch64_round_page(vmst->hdr.pmapsize, vmst->page_size);
        if (_kvm_pt_init(kd, vmst->hdr.dumpavailsize, dump_avail_off,
            vmst->hdr.bitmapsize, off, sparse_off, vmst->page_size) == -1) {
                return (-1);
        }
        off += aarch64_round_page(vmst->hdr.bitmapsize, vmst->page_size);

        if (_kvm_pmap_init(kd, vmst->hdr.pmapsize, off) == -1) {
                return (-1);
        }
        off += aarch64_round_page(vmst->hdr.pmapsize, vmst->page_size);

        return (0);
}

static int
_aarch64_minidump_vatop(kvm_t *kd, kvaddr_t va, off_t *pa)
{
        struct vmstate *vm;
        aarch64_physaddr_t offset;
        aarch64_pte_t l3;
        kvaddr_t l3_index;
        aarch64_physaddr_t a;
        off_t ofs;

        vm = kd->vmst;
        offset = va & (kd->vmst->page_size - 1);

        if (va >= vm->hdr.dmapbase && va < vm->hdr.dmapend) {
                a = aarch64_trunc_page(va - vm->hdr.dmapbase + vm->hdr.dmapphys,
                    kd->vmst->page_size);
                ofs = _kvm_pt_find(kd, a, kd->vmst->page_size);
                if (ofs == -1) {
                        _kvm_err(kd, kd->program, "_aarch64_minidump_vatop: "
                            "direct map address 0x%jx not in minidump",
                            (uintmax_t)va);
                        goto invalid;
                }
                *pa = ofs + offset;
                return (kd->vmst->page_size - offset);
        } else if (va >= vm->hdr.kernbase) {
                l3_index = (va - vm->hdr.kernbase) >> kd->vmst->l3_shift;
                if (l3_index >= vm->hdr.pmapsize / sizeof(l3))
                        goto invalid;
                l3 = _aarch64_pte_get(kd, l3_index);
                if ((l3 & AARCH64_ATTR_DESCR_MASK) != AARCH64_L3_PAGE) {
                        _kvm_err(kd, kd->program,
                            "_aarch64_minidump_vatop: pde not valid");
                        goto invalid;
                }
                a = l3 & ~AARCH64_ATTR_MASK;
                ofs = _kvm_pt_find(kd, a, kd->vmst->page_size);
                if (ofs == -1) {
                        _kvm_err(kd, kd->program, "_aarch64_minidump_vatop: "
                            "physical address 0x%jx not in minidump",
                            (uintmax_t)a);
                        goto invalid;
                }
                *pa = ofs + offset;
                return (kd->vmst->page_size - offset);
        } else {
                _kvm_err(kd, kd->program,
            "_aarch64_minidump_vatop: virtual address 0x%jx not minidumped",
                    (uintmax_t)va);
                goto invalid;
        }

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

static int
_aarch64_minidump_kvatop(kvm_t *kd, kvaddr_t va, off_t *pa)
{

        if (ISALIVE(kd)) {
                _kvm_err(kd, 0,
                    "_aarch64_minidump_kvatop called in live kernel!");
                return (0);
        }
        return (_aarch64_minidump_vatop(kd, va, pa));
}

static int
_aarch64_native(kvm_t *kd __unused)
{

#ifdef __aarch64__
        return (1);
#else
        return (0);
#endif
}

static vm_prot_t
_aarch64_entry_to_prot(aarch64_pte_t pte)
{
        vm_prot_t prot = VM_PROT_READ;

        /* Source: arm64/arm64/pmap.c:pmap_protect() */
        if ((pte & AARCH64_ATTR_AP(AARCH64_ATTR_AP_RO)) == 0)
                prot |= VM_PROT_WRITE;
        if ((pte & AARCH64_ATTR_XN) == 0)
                prot |= VM_PROT_EXECUTE;
        return prot;
}

static int
_aarch64_minidump_walk_pages(kvm_t *kd, kvm_walk_pages_cb_t *cb, void *arg)
{
        struct vmstate *vm = kd->vmst;
        u_long nptes = vm->hdr.pmapsize / sizeof(aarch64_pte_t);
        u_long bmindex, dva, pa, pteindex, va;
        struct kvm_bitmap bm;
        vm_prot_t prot;
        int ret = 0;

        if (!_kvm_bitmap_init(&bm, vm->hdr.bitmapsize, &bmindex))
                return (0);

        for (pteindex = 0; pteindex < nptes; pteindex++) {
                aarch64_pte_t pte = _aarch64_pte_get(kd, pteindex);

                if ((pte & AARCH64_ATTR_DESCR_MASK) != AARCH64_L3_PAGE)
                        continue;

                va = vm->hdr.kernbase + (pteindex << kd->vmst->l3_shift);
                pa = pte & ~AARCH64_ATTR_MASK;
                dva = vm->hdr.dmapbase + pa;
                if (!_kvm_visit_cb(kd, cb, arg, pa, va, dva,
                    _aarch64_entry_to_prot(pte), kd->vmst->page_size, 0)) {
                        goto out;
                }
        }

        while (_kvm_bitmap_next(&bm, &bmindex)) {
                pa = _kvm_bit_id_pa(kd, bmindex, kd->vmst->page_size);
                if (pa == _KVM_PA_INVALID)
                        break;
                dva = vm->hdr.dmapbase + pa;
                if (vm->hdr.dmapend < (dva + kd->vmst->page_size))
                        break;
                va = 0;
                prot = VM_PROT_READ | VM_PROT_WRITE;
                if (!_kvm_visit_cb(kd, cb, arg, pa, va, dva,
                    prot, kd->vmst->page_size, 0)) {
                        goto out;
                }
        }
        ret = 1;

out:
        _kvm_bitmap_deinit(&bm);
        return (ret);
}

static struct kvm_arch kvm_aarch64_minidump = {
        .ka_probe = _aarch64_minidump_probe,
        .ka_initvtop = _aarch64_minidump_initvtop,
        .ka_freevtop = _aarch64_minidump_freevtop,
        .ka_kvatop = _aarch64_minidump_kvatop,
        .ka_native = _aarch64_native,
        .ka_walk_pages = _aarch64_minidump_walk_pages,
};

KVM_ARCH(kvm_aarch64_minidump);