/*-
 * Copyright (c) 2006 Peter Wemm
 * 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/minidump_machdep.c,v 1.10 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/device.h>
#include <sys/globaldata.h>
#include <sys/kernel.h>
#include <sys/kerneldump.h>
#include <sys/msgbuf.h>
#include <sys/kbio.h>
#include <vm/vm.h>
#include <vm/vm_kern.h>
#include <vm/pmap.h>
#include <machine/atomic.h>
#include <machine/elf.h>
#include <machine/globaldata.h>
#include <machine/md_var.h>
#include <machine/vmparam.h>
#include <machine/minidump.h>

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

/*
 * 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)

uint64_t *vm_page_dump;
vm_offset_t vm_page_dump_size;

static struct kerneldumpheader kdh;
static off_t dumplo;

/* Handle chunked writes. */
static size_t fragsz;
static void *dump_va;
static size_t counter, progress;

CTASSERT(sizeof(*vm_page_dump) == 8);

static int
is_dumpable(vm_paddr_t pa)
{
        int i;

        for (i = 0; dump_avail[i].phys_beg || dump_avail[i].phys_end; ++i) {
                if (pa >= dump_avail[i].phys_beg && pa < dump_avail[i].phys_end)
                        return (1);
        }
        return (0);
}

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

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

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

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

static int
blk_write(struct dumperinfo *di, char *ptr, vm_paddr_t pa, size_t sz)
{
        size_t len;
        int error, i, c;
        int max_iosize;

        error = 0;
        if ((sz & PAGE_MASK)) {
                kprintf("size not page aligned\n");
                return (EINVAL);
        }
        if (ptr != NULL && pa != 0) {
                kprintf("can't have both va and pa!\n");
                return (EINVAL);
        }
        if (pa != 0 && (((uintptr_t)pa) & PAGE_MASK) != 0) {
                kprintf("address not page aligned\n");
                return (EINVAL);
        }
        if (ptr != NULL) {
                /*
                 * If we're doing a virtual dump, flush any
                 * pre-existing pa pages
                 */
                error = blk_flush(di);
                if (error)
                        return (error);
        }
        max_iosize = min(MAXPHYS, di->maxiosize);
        while (sz) {
                len = max_iosize - fragsz;
                if (len > sz)
                        len = sz;
                counter += len;
                progress -= len;
                if (counter >> 24) {
                        kprintf(" %ld", PG2MB(progress >> PAGE_SHIFT));
                        counter &= (1<<24) - 1;
                }
                if (ptr) {
                        /*kprintf("s");*/
                        error = dev_ddump(di->priv, ptr, 0, dumplo, len);
                        /* kprintf("t");*/
                        if (error)
                                return (error);
                        dumplo += len;
                        ptr += len;
                        sz -= len;
                } else {
                        for (i = 0; i < len; i += PAGE_SIZE) {
                                dump_va = pmap_kenter_temporary(pa + i,
                                                (i + fragsz) >> PAGE_SHIFT);
                        }
                        smp_invltlb();
                        fragsz += len;
                        pa += len;
                        sz -= len;
                        if (fragsz == max_iosize) {
                                error = blk_flush(di);
                                if (error)
                                        return (error);
                        }
                }
        }

        /* Check for user abort. */
        c = cncheckc();
        if (c == 0x03)
                return (ECANCELED);
        if (c != -1 && c != NOKEY)
                kprintf(" (CTRL-C to abort) ");

        return (0);
}

/* A fake page table page, to avoid having to handle both 4K and 2M pages */
static pt_entry_t fakept[NPTEPG];

void
minidumpsys(struct dumperinfo *di)
{
        uint64_t dumpsize;
        uint64_t ptesize;
        vm_offset_t va;
        vm_offset_t kern_end;
        int error;
        uint64_t bits;
        uint64_t *pdp, *pd, *pt, pa;
        int i, j, k, bit;
        int kpdp, klo, khi;
        int lpdp = -1;
        long lpdpttl = 0;
        struct minidumphdr2 mdhdr;
        struct mdglobaldata *md;

        cnpoll(TRUE);
        counter = 0;

        /*
         * minidump page table format is an array of PD entries (1GB pte's),
         * representing the entire user and kernel virtual address space
         * (256TB).
         *
         * However, we will only dump the KVM portion of this space.  And we
         * only copy the PDP pages for direct access, the PD and PT pages
         * will be included in the dump as part of the physical map.
         */
        ptesize = NPML4EPG * NPDPEPG * 8;

        /*
         * Walk page table pages, set bits in vm_page_dump.
         *
         * NOTE: kernel_vm_end can actually be below KERNBASE.
         *       Just use KvaEnd.  Also note that loops which go
         *       all the way to the end of the address space might
         *       overflow the loop variable.
         */
        md = (struct mdglobaldata *)globaldata_find(0);

        kern_end = KvaEnd;
        if (kern_end < (vm_offset_t)&(md[ncpus]))
                kern_end = (vm_offset_t)&(md[ncpus]);

        pdp = (uint64_t *)PHYS_TO_DMAP(KPDPphys);
        for (va = VM_MIN_KERNEL_ADDRESS; va < kern_end; va += NBPDR) {
                /*
                 * The loop probably overflows a 64-bit int due to NBPDR.
                 */
                if (va < VM_MIN_KERNEL_ADDRESS)
                        break;

                /*
                 * KPDPphys[] is relative to VM_MIN_KERNEL_ADDRESS. It
                 * contains NKPML4E PDP pages (so we can get to all kernel
                 * PD entries from this array).
                 */
                i = ((va - VM_MIN_KERNEL_ADDRESS) >> PDPSHIFT) &
                    (NPML4EPG * NPDPEPG - 1);
                if (i != lpdp) {
                        lpdp = i;
                        lpdpttl = 0;
                }

                /*
                 * Calculate the PD index in the PDP.  Each PD represents 1GB.
                 * KVA space can cover multiple PDP pages.  The PDP array
                 * has been initialized for the entire kernel address space.
                 *
                 * We include the PD entries in the PDP in the dump
                 */
                i = ((va - VM_MIN_KERNEL_ADDRESS) >> PDPSHIFT) &
                    (NPML4EPG * NPDPEPG - 1);
                if ((pdp[i] & kernel_pmap->pmap_bits[PG_V_IDX]) == 0)
                        continue;

                /*
                 * Add the PD page from the PDP to the dump
                 */
                dump_add_page(pdp[i] & PG_FRAME);
                lpdpttl += PAGE_SIZE;

                pd = (uint64_t *)PHYS_TO_DMAP(pdp[i] & PG_FRAME);
                j = ((va >> PDRSHIFT) & ((1ul << NPDEPGSHIFT) - 1));
                if ((pd[j] & (kernel_pmap->pmap_bits[PG_PS_IDX] | kernel_pmap->pmap_bits[PG_V_IDX])) ==
                    (kernel_pmap->pmap_bits[PG_PS_IDX] | kernel_pmap->pmap_bits[PG_V_IDX]))  {
                        /* This is an entire 2M page. */
                        lpdpttl += PAGE_SIZE * NPTEPG;
                        pa = pd[j] & PG_PS_FRAME;
                        for (k = 0; k < NPTEPG; k++) {
                                if (is_dumpable(pa))
                                        dump_add_page(pa);
                                pa += PAGE_SIZE;
                        }
                } else if ((pd[j] & kernel_pmap->pmap_bits[PG_V_IDX]) ==
                           kernel_pmap->pmap_bits[PG_V_IDX]) {
                        /*
                         * Add the PT page from the PD to the dump (it is no
                         * longer included in the ptemap.
                         */
                        dump_add_page(pd[j] & PG_FRAME);
                        lpdpttl += PAGE_SIZE;

                        /* set bit for each valid page in this 2MB block */
                        pt = (uint64_t *)PHYS_TO_DMAP(pd[j] & PG_FRAME);
                        for (k = 0; k < NPTEPG; k++) {
                                if ((pt[k] & kernel_pmap->pmap_bits[PG_V_IDX])
                                    == kernel_pmap->pmap_bits[PG_V_IDX]) {
                                        pa = pt[k] & PG_FRAME;
                                        lpdpttl += PAGE_SIZE;
                                        if (is_dumpable(pa))
                                                dump_add_page(pa);
                                }
                        }
                } else {
                        /* nothing, we're going to dump a null page */
                }
        }

        /* Calculate dump size. */
        dumpsize = ptesize;
        dumpsize += round_page(msgbufp->msg_size);
        dumpsize += round_page(vm_page_dump_size);

        for (i = 0; i < vm_page_dump_size / sizeof(*vm_page_dump); i++) {
                bits = vm_page_dump[i];
                while (bits) {
                        bit = bsfq(bits);
                        pa = (((uint64_t)i * sizeof(*vm_page_dump) * NBBY) + bit) * PAGE_SIZE;
                        /* Clear out undumpable pages now if needed */
                        if (is_dumpable(pa)) {
                                dumpsize += PAGE_SIZE;
                        } else {
                                dump_drop_page(pa);
                        }
                        bits &= ~(1ul << bit);
                }
        }
        dumpsize += PAGE_SIZE;

        /* 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;
        progress = dumpsize;

        /* Initialize mdhdr */
        bzero(&mdhdr, sizeof(mdhdr));
        strcpy(mdhdr.magic, MINIDUMP2_MAGIC);
        mdhdr.version = MINIDUMP2_VERSION;
        mdhdr.msgbufsize = msgbufp->msg_size;
        mdhdr.bitmapsize = vm_page_dump_size;
        mdhdr.ptesize = ptesize;
        mdhdr.kernbase = VM_MIN_KERNEL_ADDRESS;
        mdhdr.dmapbase = DMAP_MIN_ADDRESS;
        mdhdr.dmapend = DMAP_MAX_ADDRESS;

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

        kprintf("Physical memory: %jd MB\n", (intmax_t)ptoa(physmem) / 1048576);
        kprintf("Dumping %jd MB:", (intmax_t)dumpsize >> 20);

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

        /* Dump my header */
        bzero(fakept, sizeof(fakept));
        bcopy(&mdhdr, fakept, sizeof(mdhdr));
        error = blk_write(di, (char *)fakept, 0, PAGE_SIZE);
        if (error)
                goto fail;

        /* Dump msgbuf up front */
        error = blk_write(di, (char *)msgbufp->msg_ptr, 0, round_page(msgbufp->msg_size));
        if (error)
                goto fail;

        /* Dump bitmap */
        error = blk_write(di, (char *)vm_page_dump, 0, round_page(vm_page_dump_size));
        if (error)
                goto fail;

        /*
         * Dump a full PDP array for the entire KVM space, user and kernel.
         * This is 512*512 1G PD entries (512*512*8 = 2MB).
         *
         * The minidump only dumps PD entries related to KVA space.  Also
         * note that pdp[] (aka KPDPphys[]) only covers VM_MIN_KERNEL_ADDRESS
         * to VM_MAX_KERNEL_ADDRESS.
         *
         * The actual KPDPphys[] array covers a KVA space starting at KVA
         * KPDPPHYS_KVA.
         *
         * By dumping a PDP[] array of PDs representing the entire virtual
         * address space we can expand what we dump in the future.
         */
        pdp = (uint64_t *)PHYS_TO_DMAP(KPDPphys);
        kpdp = (KPDPPHYS_KVA >> PDPSHIFT) &
                    (NPML4EPG * NPDPEPG - 1);
        klo = (int)(VM_MIN_KERNEL_ADDRESS >> PDPSHIFT) &
                    (NPML4EPG * NPDPEPG - 1);
        khi = (int)(VM_MAX_KERNEL_ADDRESS >> PDPSHIFT) &
                    (NPML4EPG * NPDPEPG - 1);

        for (i = 0; i < NPML4EPG * NPDPEPG; ++i) {
                if (i < klo || i > khi) {
                        fakept[i & (NPDPEPG - 1)] = 0;
                } else {
                        fakept[i & (NPDPEPG - 1)] = pdp[i - kpdp];
                }
                if ((i & (NPDPEPG - 1)) == (NPDPEPG - 1)) {
                        error = blk_write(di, (char *)fakept, 0, PAGE_SIZE);
                        if (error)
                                goto fail;
                        error = blk_flush(di);
                        if (error)
                                goto fail;
                }
        }

        /* Dump memory chunks */
        /* XXX cluster it up and use blk_dump() */
        for (i = 0; i < vm_page_dump_size / sizeof(*vm_page_dump); i++) {
                bits = vm_page_dump[i];
                while (bits) {
                        bit = bsfq(bits);
                        pa = (((uint64_t)i * sizeof(*vm_page_dump) * NBBY) + bit) * PAGE_SIZE;
                        error = blk_write(di, 0, pa, PAGE_SIZE);
                        if (error)
                                goto fail;
                        bits &= ~(1ul << bit);
                }
        }

        error = blk_flush(di);
        if (error)
                goto fail;

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

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

 fail:
        cnpoll(FALSE);
        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);
}

void
dump_add_page(vm_paddr_t pa)
{
        int idx, bit;

        pa >>= PAGE_SHIFT;
        idx = pa >> 6;          /* 2^6 = 64 */
        bit = pa & 63;
        atomic_set_long(&vm_page_dump[idx], 1ul << bit);
}

void
dump_drop_page(vm_paddr_t pa)
{
        int idx, bit;

        pa >>= PAGE_SHIFT;
        idx = pa >> 6;          /* 2^6 = 64 */
        bit = pa & 63;
        atomic_clear_long(&vm_page_dump[idx], 1ul << bit);
}