/*-
 * Copyright (c) 2002 Marcel Moolenaar
 * All rights reserved.
 *
 * 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 ``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 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.
 *
 * $FreeBSD: src/sys/amd64/amd64/dump_machdep.c,v 1.18 2009/05/29 21:27:12 jamie Exp $
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/conf.h>
#include <sys/cons.h>
#include <sys/sysctl.h>
#include <sys/device.h>
#include <sys/kernel.h>
#include <sys/kerneldump.h>
#include <sys/kbio.h>
#include <vm/vm.h>
#include <vm/pmap.h>
#include <machine/elf.h>
#include <machine/md_var.h>
#include <machine/thread.h>
#include <machine/vmparam.h>

CTASSERT(sizeof(struct kerneldumpheader) == 512);

static int do_minidump = 1;
TUNABLE_INT("debug.minidump", &do_minidump);
SYSCTL_INT(_debug, OID_AUTO, minidump, CTLFLAG_RW, &do_minidump, 0,
    "Enable mini crash dumps");

/*
 * Don't touch the first SIZEOF_METADATA bytes on the dump device. This
 * is to protect us from metadata and to protect metadata from us.
 */
#define SIZEOF_METADATA         (64*1024)

#define MD_ALIGN(x)     (((off_t)(x) + PAGE_MASK) & ~PAGE_MASK)
#define DEV_ALIGN(x)    roundup2((off_t)(x), DEV_BSIZE)

struct md_pa {
        vm_paddr_t md_start;
        vm_paddr_t md_size;
};

typedef int callback_t(struct md_pa *, int, void *);

static struct kerneldumpheader kdh;
static off_t dumplo, fileofs;

/* Handle buffered writes. */
static char buffer[DEV_BSIZE];
static size_t fragsz;

static struct md_pa dump_map[VM_PHYSSEG_MAX+1];

static void
md_pa_init(void)
{
        int n;

        bzero(dump_map, sizeof(dump_map));
        for (n = 0; n < NELEM(dump_map); n++) {
                if (dump_avail[n].phys_beg == 0 && dump_avail[n].phys_end == 0)
                        break;
                dump_map[n].md_start = dump_avail[n].phys_beg;
                dump_map[n].md_size = dump_avail[n].phys_end -
                                      dump_avail[n].phys_beg;
        }
}

static struct md_pa *
md_pa_first(void)
{

        return (&dump_map[0]);
}

static struct md_pa *
md_pa_next(struct md_pa *mdp)
{

        mdp++;
        if (mdp->md_size == 0)
                mdp = NULL;
        return (mdp);
}

static int
buf_write(struct dumperinfo *di, char *ptr, size_t sz)
{
        size_t len;
        int error;

        while (sz) {
                len = DEV_BSIZE - fragsz;
                if (len > sz)
                        len = sz;
                bcopy(ptr, buffer + fragsz, len);
                fragsz += len;
                ptr += len;
                sz -= len;
                if (fragsz == DEV_BSIZE) {
                        error = dev_ddump(di->priv, buffer, 0, dumplo,
                            DEV_BSIZE);
                        if (error)
                                return error;
                        dumplo += DEV_BSIZE;
                        fragsz = 0;
                }
        }

        return (0);
}

static int
buf_flush(struct dumperinfo *di)
{
        int error;

        if (fragsz == 0)
                return (0);

        error = dev_ddump(di->priv, buffer, 0, dumplo, DEV_BSIZE);
        dumplo += DEV_BSIZE;
        fragsz = 0;
        return (error);
}

#define PG2MB(pgs) ((pgs + (1 << 8) - 1) >> 8)

static int
cb_dumpdata(struct md_pa *mdp, int seqnr, void *arg)
{
        struct dumperinfo *di = (struct dumperinfo*)arg;
        vm_paddr_t a, pa;
        void *va;
        uint64_t pgs;
        size_t counter, sz, chunk;
        int i, c, error;
        int max_iosize;

        error = 0;      /* catch case in which chunk size is 0 */
        counter = 0;    /* Update twiddle every 16MB */
        va = NULL;
        pgs = mdp->md_size / PAGE_SIZE;
        pa = mdp->md_start;
        max_iosize = min(MAXPHYS, di->maxiosize);

        kprintf("  chunk %d: %ldMB (%ld pages)", seqnr, PG2MB(pgs), pgs);

        cnpoll(TRUE);
        while (pgs) {
                chunk = pgs;
                if (chunk > (max_iosize/PAGE_SIZE))
                        chunk = max_iosize/PAGE_SIZE;
                sz = chunk << PAGE_SHIFT;
                counter += sz;
                if (counter >> 24) {
                        kprintf(" %ld", PG2MB(pgs));
                        counter &= (1<<24) - 1;
                }
                for (i = 0; i < chunk; i++) {
                        a = pa + i * PAGE_SIZE;
                        va = pmap_kenter_temporary(trunc_page(a), i);
                }
                smp_invltlb();
                error = dev_ddump(di->priv, va, 0, dumplo, sz);
                if (error)
                        break;
                dumplo += sz;
                pgs -= chunk;
                pa += sz;

                /* Check for user abort. */
                c = cncheckc();
                if (c == 0x03) {
                        error = ECANCELED;
                        goto done;
                }
                if (c != -1 && c != NOKEY)
                        kprintf(" (CTRL-C to abort) ");
        }
        kprintf(" ... %s\n", (error) ? "fail" : "ok");
done:
        cnpoll(FALSE);
        return (error);
}

static int
cb_dumphdr(struct md_pa *mdp, int seqnr, void *arg)
{
        struct dumperinfo *di = (struct dumperinfo*)arg;
        Elf_Phdr phdr;
        uint64_t size;
        int error;

        size = mdp->md_size;
        bzero(&phdr, sizeof(phdr));
        phdr.p_type = PT_LOAD;
        phdr.p_flags = PF_R;                    /* XXX */
        phdr.p_offset = fileofs;
        phdr.p_vaddr = mdp->md_start;
        phdr.p_paddr = mdp->md_start;
        phdr.p_filesz = size;
        phdr.p_memsz = size;
        phdr.p_align = PAGE_SIZE;

        error = buf_write(di, (char*)&phdr, sizeof(phdr));
        fileofs += phdr.p_filesz;
        return (error);
}

static int
cb_size(struct md_pa *mdp, int seqnr, void *arg)
{
        uint64_t *sz = (uint64_t*)arg;

        *sz += (uint64_t)mdp->md_size;
        return (0);
}

static int
foreach_chunk(callback_t cb, void *arg)
{
        struct md_pa *mdp;
        int error, seqnr;

        seqnr = 0;
        mdp = md_pa_first();
        while (mdp != NULL) {
                error = (*cb)(mdp, seqnr++, arg);
                if (error)
                        return (-error);
                mdp = md_pa_next(mdp);
        }
        return (seqnr);
}

void
md_dumpsys(struct dumperinfo *di)
{
        Elf_Ehdr ehdr;
        uint64_t dumpsize;
        off_t hdrgap;
        size_t hdrsz;
        int error;

        /*
         * Save context if dump called without panic.
         */
        if (dumpthread == NULL) {
                savectx(&dumppcb);
                dumpthread = curthread;
        }

        if (do_minidump) {
                minidumpsys(di);
                return;
        }
        bzero(&ehdr, sizeof(ehdr));
        ehdr.e_ident[EI_MAG0] = ELFMAG0;
        ehdr.e_ident[EI_MAG1] = ELFMAG1;
        ehdr.e_ident[EI_MAG2] = ELFMAG2;
        ehdr.e_ident[EI_MAG3] = ELFMAG3;
        ehdr.e_ident[EI_CLASS] = ELF_CLASS;
#if BYTE_ORDER == LITTLE_ENDIAN
        ehdr.e_ident[EI_DATA] = ELFDATA2LSB;
#else
        ehdr.e_ident[EI_DATA] = ELFDATA2MSB;
#endif
        ehdr.e_ident[EI_VERSION] = EV_CURRENT;
        ehdr.e_ident[EI_OSABI] = ELFOSABI_STANDALONE;   /* XXX big picture? */
        ehdr.e_type = ET_CORE;
        ehdr.e_machine = EM_X86_64;
        ehdr.e_phoff = sizeof(ehdr);
        ehdr.e_flags = 0;
        ehdr.e_ehsize = sizeof(ehdr);
        ehdr.e_phentsize = sizeof(Elf_Phdr);
        ehdr.e_shentsize = sizeof(Elf_Shdr);

        md_pa_init();

        /* Calculate dump size. */
        dumpsize = 0L;
        ehdr.e_phnum = foreach_chunk(cb_size, &dumpsize);
        hdrsz = ehdr.e_phoff + ehdr.e_phnum * ehdr.e_phentsize;
        fileofs = MD_ALIGN(hdrsz);
        dumpsize += fileofs;
        hdrgap = fileofs - DEV_ALIGN(hdrsz);

        /* Determine dump offset on device. */
        if (di->mediasize < SIZEOF_METADATA + dumpsize + sizeof(kdh) * 2) {
                error = ENOSPC;
                goto fail;
        }
        dumplo = di->mediaoffset + di->mediasize - dumpsize;
        dumplo -= sizeof(kdh) * 2;

        mkdumpheader(&kdh, KERNELDUMPMAGIC, KERNELDUMP_AMD64_VERSION,
            dumpsize, di->blocksize);

        kprintf("Dumping %llu MB (%d chunks)\n", (long long)dumpsize >> 20,
            ehdr.e_phnum);

        /* Dump leader */
        error = dev_ddump(di->priv, &kdh, 0, dumplo, sizeof(kdh));
        if (error)
                goto fail;
        dumplo += sizeof(kdh);

        /* Dump ELF header */
        error = buf_write(di, (char*)&ehdr, sizeof(ehdr));
        if (error)
                goto fail;

        /* Dump program headers */
        error = foreach_chunk(cb_dumphdr, di);
        if (error < 0)
                goto fail;
        buf_flush(di);

        /*
         * All headers are written using blocked I/O, so we know the
         * current offset is (still) block aligned. Skip the alignement
         * in the file to have the segment contents aligned at page
         * boundary. We cannot use MD_ALIGN on dumplo, because we don't
         * care and may very well be unaligned within the dump device.
         */
        dumplo += hdrgap;

        /* Dump memory chunks (updates dumplo) */
        error = foreach_chunk(cb_dumpdata, di);
        if (error < 0)
                goto fail;

        /* Dump trailer */
        error = dev_ddump(di->priv, &kdh, 0, dumplo, sizeof(kdh));
        if (error)
                goto fail;

        /* Signal completion, signoff and exit stage left. */
        dev_ddump(di->priv, NULL, 0, 0, 0);
        kprintf("\nDump complete\n");
        return;

 fail:
        if (error < 0)
                error = -error;

        if (error == ECANCELED)
                kprintf("\nDump aborted\n");
        else if (error == ENOSPC)
                kprintf("\nDump failed. Partition too small.\n");
        else
                kprintf("\n** DUMP FAILED (ERROR %d) **\n", error);
}