/*      $OpenBSD: kvm_alpha.c,v 1.17 2021/12/01 16:53:28 deraadt Exp $  */
/*      $NetBSD: kvm_alpha.c,v 1.5 1996/10/01 21:12:05 cgd Exp $        */

/*
 * Copyright (c) 1994, 1995 Carnegie-Mellon University.
 * All rights reserved.
 *
 * Author: Chris G. Demetriou
 *
 * Permission to use, copy, modify and distribute this software and
 * its documentation is hereby granted, provided that both the copyright
 * notice and this permission notice appear in all copies of the
 * software, derivative works or modified versions, and any portions
 * thereof, and that both notices appear in supporting documentation.
 *
 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
 * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
 *
 * Carnegie Mellon requests users of this software to return to
 *
 *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
 *  School of Computer Science
 *  Carnegie Mellon University
 *  Pittsburgh PA 15213-3890
 *
 * any improvements or extensions that they make and grant Carnegie the
 * rights to redistribute these changes.
 */

#define __KVM_ALPHA_PRIVATE          /* see <machine/pte.h> */

#include <sys/types.h>
#include <sys/signal.h>
#include <sys/proc.h>
#include <sys/stat.h>
#include <sys/kcore.h>
#include <machine/kcore.h>
#include <unistd.h>
#include <stdlib.h>
#include <nlist.h>
#include <kvm.h>

#include <uvm/uvm_extern.h>
#include <machine/vmparam.h>
#include <machine/pmap.h>

#include <limits.h>
#include <db.h>

#include "kvm_private.h"

struct vmstate {
        vsize_t page_shift;
};

void
_kvm_freevtop(kvm_t *kd)
{

        /* Not actually used for anything right now, but safe. */
        free(kd->vmst);
        kd->vmst = NULL;
}

int
_kvm_initvtop(kvm_t *kd)
{
        cpu_kcore_hdr_t *cpu_kh;
        struct vmstate *vm;

        vm = (struct vmstate *)_kvm_malloc(kd, sizeof(*vm));
        if (vm == NULL)
                return (-1);

        cpu_kh = kd->cpu_data;

        /* Compute page_shift. */
        for (vm->page_shift = 0; (1L << vm->page_shift) < cpu_kh->page_size;
            vm->page_shift++)
                /* nothing */ ;
        if ((1L << vm->page_shift) != cpu_kh->page_size) {
                free(vm);
                return (-1);
        }

        kd->vmst = vm;
        return (0);
}

int
_kvm_kvatop(kvm_t *kd, u_long va, paddr_t *pa)
{
        cpu_kcore_hdr_t *cpu_kh;
        struct vmstate *vm;
        int rv, page_off;
        alpha_pt_entry_t pte;
        off_t pteoff;

        if (!kd->vmst) {
                _kvm_err(kd, 0, "vatop called before initvtop");
                return (0);
        }

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

        cpu_kh = kd->cpu_data;
        vm = kd->vmst;
        page_off = va & (cpu_kh->page_size - 1);

#ifndef PAGE_SHIFT
#define PAGE_SHIFT      vm->page_shift
#endif

        if (va >= ALPHA_K0SEG_BASE && va <= ALPHA_K0SEG_END) {
                /*
                 * Direct-mapped address: just convert it.
                 */

                *pa = ALPHA_K0SEG_TO_PHYS(va);
                rv = cpu_kh->page_size - page_off;
        } else if (va >= ALPHA_K1SEG_BASE && va <= ALPHA_K1SEG_END) {
                /*
                 * Real kernel virtual address: do the translation.
                 */

                /* Find and read the L1 PTE. */
                pteoff = cpu_kh->lev1map_pa +
                    l1pte_index(va) * sizeof(alpha_pt_entry_t);
                if (_kvm_pread(kd, kd->pmfd, (char *)&pte, sizeof(pte),
                    (off_t)_kvm_pa2off(kd, pteoff)) != sizeof(pte)) {
                        _kvm_syserr(kd, 0, "could not read L1 PTE");
                        goto lose;
                }

                /* Find and read the L2 PTE. */
                if ((pte & ALPHA_PTE_VALID) == 0) {
                        _kvm_err(kd, 0, "invalid translation (invalid L1 PTE)");
                        goto lose;
                }
                pteoff = ALPHA_PTE_TO_PFN(pte) * cpu_kh->page_size +
                    l2pte_index(va) * sizeof(alpha_pt_entry_t);
                if (_kvm_pread(kd, kd->pmfd, (char *)&pte, sizeof(pte),
                    (off_t)_kvm_pa2off(kd, pteoff)) != sizeof(pte)) {
                        _kvm_syserr(kd, 0, "could not read L2 PTE");
                        goto lose;
                }

                /* Find and read the L3 PTE. */
                if ((pte & ALPHA_PTE_VALID) == 0) {
                        _kvm_err(kd, 0, "invalid translation (invalid L2 PTE)");
                        goto lose;
                }
                pteoff = ALPHA_PTE_TO_PFN(pte) * cpu_kh->page_size +
                    l3pte_index(va) * sizeof(alpha_pt_entry_t);
                if (_kvm_pread(kd, kd->pmfd, (char *)&pte, sizeof(pte),
                    (off_t)_kvm_pa2off(kd, pteoff)) != sizeof(pte)) {
                        _kvm_syserr(kd, 0, "could not read L3 PTE");
                        goto lose;
                }

                /* Fill in the PA. */
                if ((pte & ALPHA_PTE_VALID) == 0) {
                        _kvm_err(kd, 0, "invalid translation (invalid L3 PTE)");
                        goto lose;
                }
                *pa = ALPHA_PTE_TO_PFN(pte) * cpu_kh->page_size + page_off;
                rv = cpu_kh->page_size - page_off;
        } else {
                /*
                 * Bogus address (not in KV space): punt.
                 */

                _kvm_err(kd, 0, "invalid kernel virtual address");
lose:
                *pa = -1;
                rv = 0;
        }

        return (rv);
}

/*
 * 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 *cpu_kh;
        phys_ram_seg_t *ramsegs;
        off_t off;
        int i;

        cpu_kh = kd->cpu_data;
        ramsegs = (phys_ram_seg_t *)((char *)cpu_kh + _ALIGN(sizeof *cpu_kh));

        off = 0;
        for (i = 0; i < cpu_kh->nmemsegs; i++) {
                if (pa >= ramsegs[i].start &&
                   (pa - ramsegs[i].start) < ramsegs[i].size) {
                        off += (pa - ramsegs[i].start);
                        break;
                }
                off += ramsegs[i].size;
        }
        return (kd->dump_off + off);
}