/*-
 * Copyright (C) 2010-2014 Nathan Whitehorn
 * 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 TOOLS GMBH 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.
 */

#include <stand.h>
#include <sys/param.h>
#include <sys/boot.h>
#ifdef LOADER_FDT_SUPPORT
#include <fdt_platform.h>
#endif

#include <machine/cpufunc.h>
#include <bootstrap.h>
#include "host_syscall.h"
#include "kboot.h"
#include "stand.h"
#include <smbios.h>

int kboot_getdev(void **vdev, const char *devspec, const char **path);
ssize_t kboot_copyin(const void *src, vm_offset_t dest, const size_t len);
ssize_t kboot_copyout(vm_offset_t src, void *dest, const size_t len);
ssize_t kboot_readin(readin_handle_t fd, vm_offset_t dest, const size_t len);
int kboot_autoload(void);
static void kboot_zfs_probe(void);

struct arch_switch      archsw = {
        .arch_getdev = kboot_getdev,
        .arch_copyin = kboot_copyin,
        .arch_copyout = kboot_copyout,
        .arch_readin = kboot_readin,
        .arch_autoload = kboot_autoload,
        .arch_zfs_probe = kboot_zfs_probe,
};

extern int command_fdt_internal(int argc, char *argv[]);

/*
 * On amd64, KERNSTART is where the first actual kernel page is mapped, after
 * the compatibility mapping. We reserve 2MB at the start of the address space
 * for the page tables, etc, and so need to offset this there (and only there).
 * The loader needs to know about this so we can pad everything to the proper
 * place in PA. Ideally, we'd include vmparam.h to figure this out, but the
 * macros it uses are not easily available in this compile environment, so we
 * hard code that knowledge here.
 */
#if defined(__amd64__)
#define KERN_PADDING (2 << 20)
#else
#define KERN_PADDING 0
#endif

#define PA_INVAL (vm_offset_t)-1
static vm_offset_t pa_start = PA_INVAL;
static vm_offset_t offset;

static uint64_t commit_limit;
static uint64_t committed_as;
static uint64_t mem_avail;

static void
memory_limits(void)
{
        int fd;
        char buf[128];

        /*
         * To properly size the slabs, we need to find how much memory we can
         * commit to using. commit_limit is the max, while commited_as is the
         * current total. We can use these later to allocate the largetst amount
         * of memory possible so we can support larger ram disks than we could
         * by using fixed segment sizes. We also grab the memory available so
         * we don't use more than 49% of that.
         */
        fd = open("host:/proc/meminfo", O_RDONLY);
        if (fd != -1) {
                while (fgetstr(buf, sizeof(buf), fd) > 0) {
                        if (strncmp(buf, "MemAvailable:", 13) == 0) {
                                mem_avail = strtoll(buf + 13, NULL, 0);
                                mem_avail <<= 10; /* Units are kB */
                        } else if (strncmp(buf, "CommitLimit:", 12) == 0) {
                                commit_limit = strtoll(buf + 13, NULL, 0);
                                commit_limit <<= 10; /* Units are kB */
                        } else if (strncmp(buf, "Committed_AS:", 13) == 0) {
                                committed_as = strtoll(buf + 14, NULL, 0);
                                committed_as <<= 10; /* Units are kB */
                        }
                }
        } else {
                /* Otherwise, on FreeBSD host, for testing 32GB host: */
                mem_avail = 31ul << 30;                 /* 31GB free */
                commit_limit = mem_avail * 9 / 10;      /* 90% comittable */
                committed_as = 20ul << 20;              /* 20MB used */
        }
        printf("Commit limit: %lld Committed bytes %lld Available %lld\n",
            (long long)commit_limit, (long long)committed_as,
            (long long)mem_avail);
        close(fd);
}

/*
 * NB: getdev should likely be identical to this most places, except maybe
 * we should move to storing the length of the platform devdesc.
 */
int
kboot_getdev(void **vdev, const char *devspec, const char **path)
{
        struct devdesc **dev = (struct devdesc **)vdev;
        int                             rv;

        /*
         * If it looks like this is just a path and no device, go with the
         * current device.
         */
        if (devspec == NULL || strchr(devspec, ':') == NULL) {
                if (((rv = devparse(dev, getenv("currdev"), NULL)) == 0) &&
                    (path != NULL))
                        *path = devspec;
                return (rv);
        }

        /*
         * Try to parse the device name off the beginning of the devspec
         */
        return (devparse(dev, devspec, path));
}

static int
parse_args(int argc, const char **argv)
{
        int howto = 0;

        /*
         * When run as init, sometimes argv[0] is a EFI-ESP path, other times
         * it's the name of the init program, and sometimes it's a placeholder
         * string, so we exclude it here. For the other args, look for DOS-like
         * and Unix-like absolte paths and exclude parsing it if we find that,
         * otherwise parse it as a command arg (so looking for '-X', 'foo' or
         * 'foo=bar'). This is a little different than EFI where it argv[0]
         * often times is the first argument passed in. There are cases when
         * linux-booting via EFI that we have the EFI path we used to run
         * bootXXX.efi as the arguments to init, so we need to exclude the paths
         * there as well.
         */
        for (int i = 1; i < argc; i++) {
                if (argv[i][0] != '\\' && argv[i][0] != '/') {
                        howto |= boot_parse_arg(argv[i]);
                }
        }

        return (howto);
}

static vm_offset_t rsdp;

static vm_offset_t
kboot_rsdp_from_efi(void)
{
        char buffer[512 + 1];
        char *walker, *ep;

        if (!file2str("/sys/firmware/efi/systab", buffer, sizeof(buffer)))
                return (0);     /* Not an EFI system */
        ep = buffer + strlen(buffer);
        walker = buffer;
        while (walker < ep) {
                if (strncmp("ACPI20=", walker, 7) == 0)
                        return((vm_offset_t)strtoull(walker + 7, NULL, 0));
                if (strncmp("ACPI=", walker, 5) == 0)
                        return((vm_offset_t)strtoull(walker + 5, NULL, 0));
                walker += strcspn(walker, "\n") + 1;
        }
        return (0);
}

static void
find_acpi(void)
{
        rsdp = kboot_rsdp_from_efi();
#if 0   /* maybe for amd64 */
        if (rsdp == 0)
                rsdp = find_rsdp_arch();
#endif
}

vm_offset_t
acpi_rsdp(void)
{
        return (rsdp);
}

bool
has_acpi(void)
{
        return rsdp != 0;
}

/*
 * SMBIOS support. We map the physical memory address we get into a VA in this
 * address space with mmap with 64k pages. Once we're done, we cleanup any
 * mappings we made.
 */

#define MAX_MAP 10
#define PAGE    (64<<10)

static struct mapping
{
        uintptr_t pa;
        caddr_t va;
} map[MAX_MAP];
static bool smbios_mmap_file;
static int smbios_fd;
static int nmap;

caddr_t ptov(uintptr_t pa)
{
        caddr_t va;
        uintptr_t pa2;
        struct mapping *m = map;

        if (smbios_mmap_file)
                pa2 = rounddown(pa, PAGE);
        else
                pa2 = pa;
        for (int i = 0; i < nmap; i++, m++) {
                if (m->pa == pa2) {
                        return (m->va + pa - m->pa);
                }
        }
        if (!smbios_mmap_file)
                panic("Out of bounds smbios access");
        if (nmap == MAX_MAP)
                panic("Too many maps for smbios");

        /*
         * host_mmap returns small negative numbers on errors, can't return an
         * error here, so we have to panic. The Linux wrapper will set errno
         * based on this and then return HOST_MAP_FAILED. Since we're calling
         * the raw system call we have to do that ourselves.
         */
        va = host_mmap(0, PAGE, HOST_PROT_READ, HOST_MAP_SHARED, smbios_fd, pa2);
        if (is_linux_error((long)va))
                panic("smbios mmap offset %#jx failed", (uintmax_t)pa2);
        m = &map[nmap++];
        m->pa = pa2;
        m->va = va;
        return (m->va + pa - m->pa);
}

static void
smbios_cleanup(void)
{
        for (int i = 0; i < nmap; i++) {
                host_munmap(map[i].va, PAGE);
        }
}

static vm_offset_t
kboot_find_smbios(void)
{
        char buffer[512 + 1];
        char *walker, *ep;

        if (!file2str("/sys/firmware/efi/systab", buffer, sizeof(buffer)))
                return (0);     /* Not an EFI system */
        ep = buffer + strlen(buffer);
        walker = buffer;
        while (walker <= ep) {
                /*
                 * Linux outputs the v3 table first if present, so we will
                 * choose it in priority.
                 */
                if (strncmp("SMBIOS3=", walker, 8) == 0)
                        return((vm_offset_t)strtoull(walker + 8, NULL, 0));
                if (strncmp("SMBIOS=", walker, 7) == 0)
                        return((vm_offset_t)strtoull(walker + 7, NULL, 0));
                walker += strcspn(walker, "\n") + 1;
        }
        return (0);
}

static void
find_smbios(void)
{
        char buf[40];
        void *dmi_data;
        uintptr_t pa;
        caddr_t va;

        pa = kboot_find_smbios();
        printf("SMBIOS at %#jx\n", (uintmax_t)pa);
        if (pa == 0)
                return;

        dmi_data = NULL;
        smbios_fd = host_open("/sys/firmware/dmi/tables/DMI", O_RDONLY, 0);
        if (smbios_fd >= 0) {
                struct host_kstat sb;
                struct mapping *m;

                if (host_fstat(smbios_fd, &sb) < 0) {
                        host_close(smbios_fd);
                        goto try_dev_mem;
                }

                dmi_data = malloc(sb.st_size);
                if (dmi_data == NULL) {
                        host_close(smbios_fd);
                        goto try_dev_mem;
                }

                host_read(smbios_fd, dmi_data, sb.st_size);

                m = &map[nmap++];
                m->pa = pa;
                m->va = dmi_data;
                smbios_mmap_file = false;
        } else {
try_dev_mem:
                smbios_fd = host_open("/dev/mem", O_RDONLY, 0);
                if (smbios_fd < 0) {
                        printf("Can't open /sys/firmware/dmi/tables/DMI or "
                            "/dev/mem to read smbios\n");
                        return;
                }
                smbios_mmap_file = true;
        }
        snprintf(buf, sizeof(buf), "%#jx", (uintmax_t)pa);
        setenv("hint.smbios.0.mem", buf, 1);

        va = ptov(pa);
        printf("Start of smbios at pa %p va %p\n", (void *)pa, va);
        smbios_detect(va);
        smbios_cleanup();
        free(dmi_data);
        host_close(smbios_fd);
}

static void
parse_file(const char *fn)
{
        struct stat st;
        int fd = -1;
        char *env = NULL;

        if (stat(fn, &st) != 0)
                return;
        fd = open(fn, O_RDONLY);
        if (fd == -1)
                return;
        env = malloc(st.st_size + 1);
        if (env == NULL)
                goto out;
        if (read(fd, env, st.st_size) != st.st_size)
                goto out;
        env[st.st_size] = '\0';
        boot_parse_cmdline(env);
out:
        free(env);
        close(fd);
}


int
main(int argc, const char **argv)
{
        void *heapbase;
        const size_t heapsize = 64*1024*1024;
        const char *bootdev;

        /* Give us a sane world if we're running as init */
        do_init();

        /*
         * Setup the heap, 64MB is minimum for ZFS booting
         */
        heapbase = host_getmem(heapsize);
        setheap(heapbase, heapbase + heapsize);

        /*
         * Set up console so we get error messages.
         */
        cons_probe();

        /*
         * Find acpi and smbios, if they exists. This allows command line and
         * later scripts to override if necessary.
         */
        find_acpi();
        find_smbios();

        /* Parse the command line args -- ignoring for now the console selection */
        parse_args(argc, argv);

        hostfs_root = getenv("hostfs_root");
        if (hostfs_root == NULL)
                hostfs_root = "/";

        /* Initialize all the devices */
        devinit();

        /* Figure out where we're booting from */
        bootdev = getenv("bootdev");
        if (bootdev == NULL)
                bootdev = hostdisk_gen_probe();
#if defined(LOADER_ZFS_SUPPORT)
        if (bootdev == NULL || strcmp(bootdev, "zfs:") == 0) {
                /*
                 * Pseudo device that says go find the right ZFS pool. This will be
                 * the first pool that we find that passes the sanity checks (eg looks
                 * like it might be vbootable) and sets currdev to the right thing based
                 * on active BEs, etc
                 */
                if (hostdisk_zfs_find_default())
                        bootdev = getenv("currdev");
        }
#endif
        if (bootdev == NULL)
                bootdev = "host:/";
        if (bootdev != NULL) {
                /*
                 * Otherwise, honor what's on the command line. If we've been
                 * given a specific ZFS partition, then we'll honor it w/o BE
                 * processing that would otherwise pick a different snapshot to
                 * boot than the default one in the pool.
                 */
                set_currdev(bootdev);
        } else {
                panic("Bootdev is still NULL");
        }

        printf("Boot device: %s with hostfs_root %s\n", bootdev, hostfs_root);

        printf("\n%s", bootprog_info);

        setenv("LINES", "24", 1);

        memory_limits();
        enumerate_memory_arch();

        interact();                     /* doesn't return */

        return (0);
}

void
exit(int code)
{
        host_exit(code);
        __unreachable();
}

void
delay(int usecs)
{
        struct host_timeval tvi, tv;
        uint64_t ti, t;
        host_gettimeofday(&tvi, NULL);
        ti = tvi.tv_sec*1000000 + tvi.tv_usec;
        do {
                host_gettimeofday(&tv, NULL);
                t = tv.tv_sec*1000000 + tv.tv_usec;
        } while (t < ti + usecs);
}

time_t
getsecs(void)
{
        struct host_timeval tv;
        host_gettimeofday(&tv, NULL);
        return (tv.tv_sec);
}

time_t
time(time_t *tloc)
{
        time_t rv;
        
        rv = getsecs();
        if (tloc != NULL)
                *tloc = rv;

        return (rv);
}

struct host_kexec_segment loaded_segments[HOST_KEXEC_SEGMENT_MAX];
int nkexec_segments = 0;

#define SEGALIGN (1ul<<20)

static ssize_t
get_phys_buffer(vm_offset_t dest, const size_t len, void **buf)
{
        int i = 0;
        const size_t segsize = 64*1024*1024;
        size_t sz, amt, l;

        if (nkexec_segments == HOST_KEXEC_SEGMENT_MAX)
                panic("Tried to load too many kexec segments");
        for (i = 0; i < nkexec_segments; i++) {
                if (dest >= (vm_offset_t)loaded_segments[i].mem &&
                    dest < (vm_offset_t)loaded_segments[i].mem +
                    loaded_segments[i].bufsz) /* Need to use bufsz since memsz is in use size */
                        goto out;
        }

        sz = segsize;
        if (nkexec_segments == 0) {
                /* how much space does this segment have */
                sz = space_avail(dest);
                /* Clip to 45% of available memory (need 2 copies) */
                sz = MIN(sz, rounddown2(mem_avail * 45 / 100, SEGALIGN));
                printf("limit to 45%% of mem_avail %zd\n", sz);
                /* And only use 95% of what we can allocate */
                sz = MIN(sz,
                    rounddown2((commit_limit - committed_as) * 95 / 100, SEGALIGN));
                printf("Allocating %zd MB for first segment\n", sz >> 20);
        }

        loaded_segments[nkexec_segments].buf = host_getmem(sz);
        loaded_segments[nkexec_segments].bufsz = sz;
        loaded_segments[nkexec_segments].mem = (void *)rounddown2(dest,SEGALIGN);
        loaded_segments[nkexec_segments].memsz = 0;

        i = nkexec_segments;
        nkexec_segments++;

out:
        /*
         * Keep track of the highest amount used in a segment
         */
        amt = dest - (vm_offset_t)loaded_segments[i].mem;
        l = min(len,loaded_segments[i].bufsz - amt);
        *buf = loaded_segments[i].buf + amt;
        if (amt + l > loaded_segments[i].memsz)
                loaded_segments[i].memsz = amt + l;
        return (l);
}

ssize_t
kboot_copyin(const void *src, vm_offset_t dest, const size_t len)
{
        ssize_t segsize, remainder;
        void *destbuf;

        if (pa_start == PA_INVAL) {
                pa_start = kboot_get_phys_load_segment();
                offset = dest;
                get_phys_buffer(pa_start, len, &destbuf);
        }

        remainder = len;
        do {
                segsize = get_phys_buffer(dest + pa_start + KERN_PADDING - offset, remainder, &destbuf);
                bcopy(src, destbuf, segsize);
                remainder -= segsize;
                src += segsize;
                dest += segsize;
        } while (remainder > 0);

        return (len);
}

ssize_t
kboot_copyout(vm_offset_t src, void *dest, const size_t len)
{
        ssize_t segsize, remainder;
        void *srcbuf;

        remainder = len;
        do {
                segsize = get_phys_buffer(src + pa_start + KERN_PADDING - offset, remainder, &srcbuf);
                bcopy(srcbuf, dest, segsize);
                remainder -= segsize;
                src += segsize;
                dest += segsize;
        } while (remainder > 0);

        return (len);
}

ssize_t
kboot_readin(readin_handle_t fd, vm_offset_t dest, const size_t len)
{
        void            *buf;
        size_t          resid, chunk, get;
        ssize_t         got;
        vm_offset_t     p;

        p = dest;

        chunk = min(PAGE_SIZE, len);
        buf = malloc(chunk);
        if (buf == NULL) {
                printf("kboot_readin: buf malloc failed\n");
                return (0);
        }

        for (resid = len; resid > 0; resid -= got, p += got) {
                get = min(chunk, resid);
                got = VECTX_READ(fd, buf, get);
                if (got <= 0) {
                        if (got < 0)
                                printf("kboot_readin: read failed\n");
                        break;
                }

                kboot_copyin(buf, p, got);
        }

        free (buf);
        return (len - resid);
}

int
kboot_autoload(void)
{

        return (0);
}

void
kboot_kseg_get(int *nseg, void **ptr)
{
        printf("kseg_get: %d segments\n", nkexec_segments);
        printf("VA               SZ       PA               MEMSZ\n");
        printf("---------------- -------- ---------------- -----\n");
        for (int a = 0; a < nkexec_segments; a++) {
                /*
                 * Truncate each segment to just what we've used in the segment,
                 * rounded up to the next page.
                 */
                loaded_segments[a].memsz = roundup2(loaded_segments[a].memsz,PAGE_SIZE);
                loaded_segments[a].bufsz = loaded_segments[a].memsz;
                printf("%016jx %08jx %016jx %08jx\n",
                        (uintmax_t)loaded_segments[a].buf,
                        (uintmax_t)loaded_segments[a].bufsz,
                        (uintmax_t)loaded_segments[a].mem,
                        (uintmax_t)loaded_segments[a].memsz);
        }

        *nseg = nkexec_segments;
        *ptr = &loaded_segments[0];
}

static void
kboot_zfs_probe(void)
{
#if defined(LOADER_ZFS_SUPPORT)
        /*
         * Open all the disks and partitions we can find to see if there are ZFS
         * pools on them.
         */
        hostdisk_zfs_probe();
#endif
}

#ifdef LOADER_FDT_SUPPORT
/*
 * Since proper fdt command handling function is defined in fdt_loader_cmd.c,
 * and declaring it as extern is in contradiction with COMMAND_SET() macro
 * (which uses static pointer), we're defining wrapper function, which
 * calls the proper fdt handling routine.
 */
static int
command_fdt(int argc, char *argv[])
{

        return (command_fdt_internal(argc, argv));
}

COMMAND_SET(fdt, "fdt", "flattened device tree handling", command_fdt);
#endif

/*
 * Support quitting.
 */
static int
command_quit(int argc, char *argv[])
{
        exit(0);
        return (CMD_OK);
}

COMMAND_SET(quit, "quit", "exit the program", command_quit);