/*-
 * Copyright (c) 1989, 1992, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software developed by the Computer Systems
 * Engineering group at Lawrence Berkeley Laboratory under DARPA contract
 * BG 91-66 and contributed to Berkeley.
 *
 * 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.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
 *
 * @(#)kvm_hp300.c      8.1 (Berkeley) 6/4/93
 * $FreeBSD: src/lib/libkvm/kvm_amd64.c,v 1.16 2003/04/30 21:05:33 peter Exp $
 */

/*
 * x86_64 machine dependent routines for kvm.  Hopefully, the forthcoming
 * vm code will one day obsolete this module.
 */

#include <sys/user.h>   /* MUST BE FIRST */
#include <sys/param.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include <sys/elf_common.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <nlist.h>

#include <cpu/pmap.h>
#include <vm/vm.h>
#include <vm/vm_param.h>

#include <machine/elf.h>

#include <limits.h>

#include "kvm.h"
#include "kvm_private.h"

#ifndef btop
#define btop(x)         (x86_64_btop(x))
#define ptob(x)         (x86_64_ptob(x))
#endif

struct vmstate {
        int             minidump;       /* 1 = minidump mode */
        void            *mmapbase;
        size_t          mmapsize;
        pml4_entry_t    *PML4;
};

/*
 * Map the ELF headers into the process' address space. We do this in two
 * steps: first the ELF header itself and using that information the whole
 * set of headers. (Taken from kvm_ia64.c)
 */
static int
_kvm_maphdrs(kvm_t *kd, size_t sz)
{
        struct vmstate *vm = kd->vmst;

        if (kd->vmst->minidump) {
                _kvm_minidump_freevtop(kd);
                return (0);
        }

        /* munmap() previous mmap(). */
        if (vm->mmapbase != NULL) {
                munmap(vm->mmapbase, vm->mmapsize);
                vm->mmapbase = NULL;
        }

        vm->mmapsize = sz;
        vm->mmapbase = mmap(NULL, sz, PROT_READ, MAP_PRIVATE, kd->pmfd, 0);
        if (vm->mmapbase == MAP_FAILED) {
                _kvm_err(kd, kd->program, "cannot mmap corefile");
                return (-1);
        }
        return (0);
}

/*
 * Translate a physical memory address to a file-offset in the crash-dump.
 * (Taken from kvm_ia64.c)
 */
static size_t
_kvm_pa2off(kvm_t *kd, uint64_t pa, off_t *ofs)
{
        Elf_Ehdr *e = kd->vmst->mmapbase;
        Elf_Phdr *p;
        int n;

        if (kd->rawdump) {
                *ofs = pa;
                return (PAGE_SIZE - ((size_t)pa & PAGE_MASK));
        }

        p = (Elf_Phdr*)((char*)e + e->e_phoff);
        n = e->e_phnum;

        while (n && (pa < p->p_paddr || pa >= p->p_paddr + p->p_memsz))
                p++, n--;
        if (n == 0)
                return (0);
        *ofs = (pa - p->p_paddr) + p->p_offset;
        return (PAGE_SIZE - ((size_t)pa & PAGE_MASK));
}

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

        if (kd->vmst->minidump) {
                _kvm_minidump_freevtop(kd);
                return;
        }

        if (vm->mmapbase != NULL)
                munmap(vm->mmapbase, vm->mmapsize);
        if (vm->PML4)
                free(vm->PML4);
        free(vm);
        kd->vmst = NULL;
}

int
_kvm_initvtop(kvm_t *kd)
{
        struct nlist nlists[2];
        u_long pa;
        u_long kernbase;
        pml4_entry_t    *PML4;
        Elf_Ehdr *ehdr;
        size_t hdrsz;
        char    minihdr[8];
        struct pcb dumppcb;

        if (pread(kd->pmfd, &minihdr, 8, 0) == 8)
                if (memcmp(&minihdr, "minidump", 8) == 0)
                        return (_kvm_minidump_initvtop(kd));

        kd->vmst = (struct vmstate *)_kvm_malloc(kd, sizeof(*kd->vmst));
        if (kd->vmst == 0) {
                _kvm_err(kd, kd->program, "cannot allocate vm");
                return (-1);
        }
        kd->vmst->PML4 = 0;

        if (_kvm_maphdrs(kd, sizeof(Elf_Ehdr)) == -1)
                return (-1);
        /*
         * Check if this is indeed an ELF header. If not, assume old style
          *dump or memory layout.
         */
        ehdr = kd->vmst->mmapbase;
        if (!IS_ELF(*ehdr)) {
                kd->rawdump = 1;
                munmap(kd->vmst->mmapbase, kd->vmst->mmapsize);
                kd->vmst->mmapbase = NULL;
        } else {
                hdrsz = ehdr->e_phoff + ehdr->e_phentsize * ehdr->e_phnum;
                if (_kvm_maphdrs(kd, hdrsz) == -1)
                        return (-1);
        }

        nlists[0].n_name = "kernbase";
        nlists[1].n_name = 0;

        if (kvm_nlist(kd, nlists) != 0) {
                _kvm_err(kd, kd->program, "bad namelist - no kernbase");
                return (-1);
        }
        kernbase = nlists[0].n_value;

        nlists[0].n_name = "dumppcb";
        nlists[1].n_name = 0;

        if (kvm_nlist(kd, nlists) != 0) {
                _kvm_err(kd, kd->program, "bad namelist - no dumppcb");
                return (-1);
        }
        if (kvm_read(kd, (nlists[0].n_value - kernbase), &dumppcb,
                     sizeof(dumppcb)) != sizeof(dumppcb)) {
                _kvm_err(kd, kd->program, "cannot read dumppcb");
                return (-1);
        }
        pa = dumppcb.pcb_cr3 & PG_FRAME;

        PML4 = _kvm_malloc(kd, PAGE_SIZE);
        if (kvm_read(kd, pa, PML4, PAGE_SIZE) != PAGE_SIZE) {
                _kvm_err(kd, kd->program, "cannot read dumppcb");
                return (-1);
        }
        kd->vmst->PML4 = PML4;
        return (0);
}

static int
_kvm_vatop(kvm_t *kd, u_long va, off_t *pa)
{
        struct vmstate *vm;
        u_long offset;
        u_long pdpe_pa;
        u_long pde_pa;
        u_long pte_pa;
        pml4_entry_t pml4e;
        pdp_entry_t pdpe;
        pd_entry_t pde;
        pt_entry_t pte;
        u_long pml4eindex;
        u_long pdpeindex;
        u_long pdeindex;
        u_long pteindex;
        u_long a;
        off_t ofs;
        size_t s;

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

        /*
         * If we are initializing (kernel page table descriptor pointer
         * not yet set) then return pa == va to avoid infinite recursion.
         */
        if (vm->PML4 == NULL) {
                s = _kvm_pa2off(kd, va, pa);
                if (s == 0) {
                        _kvm_err(kd, kd->program,
                            "_kvm_vatop: bootstrap data not in dump");
                        goto invalid;
                } else
                        return (PAGE_SIZE - offset);
        }

        pml4eindex = (va >> PML4SHIFT) & (NPML4EPG - 1);
        pml4e = vm->PML4[pml4eindex];
        if (((u_long)pml4e & X86_PG_V) == 0) {
                _kvm_err(kd, kd->program, "_kvm_vatop: pml4e not valid");
                goto invalid;
        }

        pdpeindex = (va >> PDPSHIFT) & (NPDPEPG-1);
        pdpe_pa = ((u_long)pml4e & PG_FRAME) +
            (pdpeindex * sizeof(pdp_entry_t));

        s = _kvm_pa2off(kd, pdpe_pa, &ofs);
        if (s < sizeof pdpe) {
                _kvm_err(kd, kd->program, "_kvm_vatop: pdpe_pa not found");
                goto invalid;
        }
        if (lseek(kd->pmfd, ofs, 0) == -1) {
                _kvm_syserr(kd, kd->program, "_kvm_vatop: lseek pdpe_pa");
                goto invalid;
        }
        if (read(kd->pmfd, &pdpe, sizeof pdpe) != sizeof pdpe) {
                _kvm_syserr(kd, kd->program, "_kvm_vatop: read pdpe");
                goto invalid;
        }
        if (((u_long)pdpe & X86_PG_V) == 0) {
                _kvm_err(kd, kd->program, "_kvm_vatop: pdpe not valid");
                goto invalid;
        }

        pdeindex = (va >> PDRSHIFT) & (NPDEPG-1);
        pde_pa = ((u_long)pdpe & PG_FRAME) + (pdeindex * sizeof(pd_entry_t));

        s = _kvm_pa2off(kd, pde_pa, &ofs);
        if (s < sizeof pde) {
                _kvm_syserr(kd, kd->program, "_kvm_vatop: pde_pa not found");
                goto invalid;
        }
        if (lseek(kd->pmfd, ofs, 0) == -1) {
                _kvm_err(kd, kd->program, "_kvm_vatop: lseek pde_pa");
                goto invalid;
        }
        if (read(kd->pmfd, &pde, sizeof pde) != sizeof pde) {
                _kvm_syserr(kd, kd->program, "_kvm_vatop: read pde");
                goto invalid;
        }
        if (((u_long)pde & X86_PG_V) == 0) {
                _kvm_err(kd, kd->program, "_kvm_vatop: pde not valid");
                goto invalid;
        }

        if ((u_long)pde & X86_PG_PS) {
              /*
               * No final-level page table; ptd describes one 2MB page.
               */
#define PAGE2M_MASK     (NBPDR - 1)
#define PG_FRAME2M      (~PAGE2M_MASK)
                a = ((u_long)pde & PG_FRAME2M) + (va & PAGE2M_MASK);
                s = _kvm_pa2off(kd, a, pa);
                if (s == 0) {
                        _kvm_err(kd, kd->program,
                            "_kvm_vatop: 2MB page address not in dump");
                        goto invalid;
                } else {
                        return (NBPDR - (va & PAGE2M_MASK));
                }
        }

        pteindex = (va >> PAGE_SHIFT) & (NPTEPG-1);
        pte_pa = ((u_long)pde & PG_FRAME) + (pteindex * sizeof(pt_entry_t));

        s = _kvm_pa2off(kd, pte_pa, &ofs);
        if (s < sizeof pte) {
                _kvm_err(kd, kd->program, "_kvm_vatop: pte_pa not found");
                goto invalid;
        }
        if (lseek(kd->pmfd, ofs, 0) == -1) {
                _kvm_syserr(kd, kd->program, "_kvm_vatop: lseek");
                goto invalid;
        }
        if (read(kd->pmfd, &pte, sizeof pte) != sizeof pte) {
                _kvm_syserr(kd, kd->program, "_kvm_vatop: read");
                goto invalid;
        }
        if (((u_long)pte & X86_PG_V) == 0) {
                _kvm_err(kd, kd->program, "_kvm_vatop: pte not valid");
                goto invalid;
        }

        a = ((u_long)pte & PG_FRAME) + offset;
        s = _kvm_pa2off(kd, a, pa);
        if (s == 0) {
                _kvm_err(kd, kd->program, "_kvm_vatop: address not in dump");
                goto invalid;
        } else
                return (PAGE_SIZE - offset);

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

int
_kvm_kvatop(kvm_t *kd, u_long va, off_t *pa)
{
        if (kd->vmst->minidump)
                return (_kvm_minidump_kvatop(kd, va, pa));

        if (kvm_ishost(kd)) {
                _kvm_err(kd, 0, "kvm_vatop called in live kernel!");
                return((off_t)0);
        }

        return (_kvm_vatop(kd, va, pa));
}