/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*
 * Copyright 2023 Oxide Computer Company
 */

/*
 * libfmd_agent contains the low-level operations that needed by the fmd
 * agents, such as page operations (status/retire/unretire), cpu operations
 * (status/online/offline), etc.
 *
 * Some operations are implemented by /dev/fm ioctls.  Those ioctls are
 * heavily versioned to allow userland patching without requiring a reboot
 * to get a matched /dev/fm.   All the ioctls use packed nvlist to interact
 * between userland and kernel.  (see fmd_agent_nvl_ioctl()).
 */

#include <fcntl.h>
#include <errno.h>
#include <unistd.h>
#include <strings.h>
#include <libnvpair.h>
#include <string.h>
#include <sys/types.h>
#include <sys/devfm.h>
#include <fmd_agent_impl.h>

int
fmd_agent_errno(fmd_agent_hdl_t *hdl)
{
        return (hdl->agent_errno);
}

int
fmd_agent_seterrno(fmd_agent_hdl_t *hdl, int err)
{
        hdl->agent_errno = err;
        return (-1);
}

const char *
fmd_agent_strerr(int err)
{
        return (strerror(err));
}

const char *
fmd_agent_errmsg(fmd_agent_hdl_t *hdl)
{
        return (fmd_agent_strerr(hdl->agent_errno));
}

static int
cleanup_set_errno(fmd_agent_hdl_t *hdl, nvlist_t *innvl, nvlist_t *outnvl,
    int err)
{
        nvlist_free(innvl);
        nvlist_free(outnvl);
        return (fmd_agent_seterrno(hdl, err));
}

/*
 * Perform /dev/fm ioctl.  The input and output data are represented by
 * name-value lists (nvlists).
 */
int
fmd_agent_nvl_ioctl(fmd_agent_hdl_t *hdl, int cmd, uint32_t ver,
    nvlist_t *innvl, nvlist_t **outnvlp)
{
        fm_ioc_data_t fid;
        int err = 0;
        char *inbuf = NULL, *outbuf = NULL;
        size_t insz = 0, outsz = 0;

        if (innvl != NULL) {
                if ((err = nvlist_size(innvl, &insz, NV_ENCODE_NATIVE)) != 0)
                        return (err);
                if (insz > FM_IOC_MAXBUFSZ)
                        return (ENAMETOOLONG);
                if ((inbuf = umem_alloc(insz, UMEM_DEFAULT)) == NULL)
                        return (errno);

                if ((err = nvlist_pack(innvl, &inbuf, &insz,
                    NV_ENCODE_NATIVE, 0)) != 0) {
                        umem_free(inbuf, insz);
                        return (err);
                }
        }

        if (outnvlp != NULL) {
                outsz = FM_IOC_OUT_BUFSZ;
        }
        for (;;) {
                if (outnvlp != NULL) {
                        outbuf = umem_alloc(outsz, UMEM_DEFAULT);
                        if (outbuf == NULL) {
                                err = errno;
                                break;
                        }
                }

                fid.fid_version = ver;
                fid.fid_insz = insz;
                fid.fid_inbuf = inbuf;
                fid.fid_outsz = outsz;
                fid.fid_outbuf = outbuf;

                if (ioctl(hdl->agent_devfd, cmd, &fid) < 0) {
                        if (errno == ENAMETOOLONG && outsz != 0 &&
                            outsz <= (FM_IOC_OUT_MAXBUFSZ / 2)) {
                                umem_free(outbuf, outsz);
                                outbuf = NULL;
                                outsz *= 2;
                        } else {
                                err = errno;
                                break;
                        }
                } else if (outnvlp != NULL) {
                        err = nvlist_unpack(fid.fid_outbuf, fid.fid_outsz,
                            outnvlp, 0);
                        break;
                } else {
                        break;
                }
        }

        if (inbuf != NULL)
                umem_free(inbuf, insz);
        if (outbuf != NULL)
                umem_free(outbuf, outsz);

        return (err);
}

/*
 * Open /dev/fm and return a handle.  ver is the overall interface version.
 */
static fmd_agent_hdl_t *
fmd_agent_open_dev(int ver, int mode)
{
        fmd_agent_hdl_t *hdl;
        int fd, err;
        nvlist_t *nvl;

        if ((fd = open("/dev/fm", mode)) < 0)
                return (NULL); /* errno is set for us */

        if ((hdl = umem_alloc(sizeof (fmd_agent_hdl_t),
            UMEM_DEFAULT)) == NULL) {
                err = errno;
                (void) close(fd);
                errno = err;
                return (NULL);
        }

        hdl->agent_devfd = fd;
        hdl->agent_version = ver;

        /*
         * Get the individual interface versions.
         */
        if ((err = fmd_agent_nvl_ioctl(hdl, FM_IOC_VERSIONS, ver, NULL, &nvl))
            < 0) {
                (void) close(fd);
                umem_free(hdl, sizeof (fmd_agent_hdl_t));
                errno = err;
                return (NULL);
        }

        hdl->agent_ioc_versions = nvl;
        return (hdl);
}

fmd_agent_hdl_t *
fmd_agent_open(int ver)
{
        if (ver > FMD_AGENT_VERSION) {
                errno = ENOTSUP;
                return (NULL);
        }
        return (fmd_agent_open_dev(ver, O_RDONLY));
}

void
fmd_agent_close(fmd_agent_hdl_t *hdl)
{
        (void) close(hdl->agent_devfd);
        nvlist_free(hdl->agent_ioc_versions);
        umem_free(hdl, sizeof (fmd_agent_hdl_t));
}

/*
 * Given a interface name, return the kernel interface version.
 */
int
fmd_agent_version(fmd_agent_hdl_t *hdl, const char *op, uint32_t *verp)
{
        int err;

        err = nvlist_lookup_uint32(hdl->agent_ioc_versions,
            op, verp);

        if (err != 0) {
                errno = err;
                return (-1);
        }
        return (0);
}

static int
fmd_agent_pageop_v1(fmd_agent_hdl_t *hdl, int cmd, nvlist_t *fmri)
{
        int err;
        nvlist_t *nvl = NULL;

        if ((err = nvlist_alloc(&nvl, NV_UNIQUE_NAME_TYPE, 0)) != 0 ||
            (err = nvlist_add_nvlist(nvl, FM_PAGE_RETIRE_FMRI, fmri)) != 0 ||
            (err = fmd_agent_nvl_ioctl(hdl, cmd, 1, nvl, NULL)) != 0)
                return (cleanup_set_errno(hdl, nvl, NULL, err));

        nvlist_free(nvl);
        return (0);
}

static int
fmd_agent_pageop(fmd_agent_hdl_t *hdl, int cmd, nvlist_t *fmri)
{
        uint32_t ver;

        if (fmd_agent_version(hdl, FM_PAGE_OP_VERSION, &ver) == -1)
                return (fmd_agent_seterrno(hdl, errno));

        switch (ver) {
        case 1:
                return (fmd_agent_pageop_v1(hdl, cmd, fmri));

        default:
                return (fmd_agent_seterrno(hdl, ENOTSUP));
        }
}

int
fmd_agent_page_retire(fmd_agent_hdl_t *hdl, nvlist_t *fmri)
{
        int rc = fmd_agent_pageop(hdl, FM_IOC_PAGE_RETIRE, fmri);
        int err = fmd_agent_errno(hdl);

        /*
         * FM_IOC_PAGE_RETIRE ioctl returns:
         *   0 - success in retiring page
         *   -1, errno = EIO - page is already retired
         *   -1, errno = EAGAIN - page is scheduled for retirement
         *   -1, errno = EINVAL - page fmri is invalid
         *   -1, errno = any else - error
         */
        if (rc == 0 || err == EIO || err == EINVAL) {
                if (rc == 0)
                        (void) fmd_agent_seterrno(hdl, 0);
                return (FMD_AGENT_RETIRE_DONE);
        }
        if (err == EAGAIN)
                return (FMD_AGENT_RETIRE_ASYNC);

        return (FMD_AGENT_RETIRE_FAIL);
}

int
fmd_agent_page_unretire(fmd_agent_hdl_t *hdl, nvlist_t *fmri)
{
        int rc = fmd_agent_pageop(hdl, FM_IOC_PAGE_UNRETIRE, fmri);
        int err = fmd_agent_errno(hdl);

        /*
         * FM_IOC_PAGE_UNRETIRE ioctl returns:
         *   0 - success in unretiring page
         *   -1, errno = EIO - page is already unretired
         *   -1, errno = EAGAIN - page couldn't be locked, still retired
         *   -1, errno = EINVAL - page fmri is invalid
         *   -1, errno = any else - error
         */
        if (rc == 0 || err == EIO || err == EINVAL) {
                if (rc == 0)
                        (void) fmd_agent_seterrno(hdl, 0);
                return (FMD_AGENT_RETIRE_DONE);
        }

        return (FMD_AGENT_RETIRE_FAIL);
}

int
fmd_agent_page_isretired(fmd_agent_hdl_t *hdl, nvlist_t *fmri)
{
        int rc = fmd_agent_pageop(hdl, FM_IOC_PAGE_STATUS, fmri);
        int err = fmd_agent_errno(hdl);

        /*
         * FM_IOC_PAGE_STATUS returns:
         *   0 - page is retired
         *   -1, errno = EAGAIN - page is scheduled for retirement
         *   -1, errno = EIO - page not scheduled for retirement
         *   -1, errno = EINVAL - page fmri is invalid
         *   -1, errno = any else - error
         */
        if (rc == 0 || err == EINVAL) {
                if (rc == 0)
                        (void) fmd_agent_seterrno(hdl, 0);
                return (FMD_AGENT_RETIRE_DONE);
        }
        if (err == EAGAIN)
                return (FMD_AGENT_RETIRE_ASYNC);

        return (FMD_AGENT_RETIRE_FAIL);
}

void
fmd_agent_cache_info_free(fmd_agent_hdl_t *hdl __unused,
    fmd_agent_cpu_cache_list_t *cache)
{
        for (uint_t cpuno = 0; cpuno < cache->fmc_ncpus; cpuno++) {
                fmd_agent_cpu_cache_t *cpu_cache = &cache->fmc_cpus[cpuno];

                if (cpu_cache->fmcc_caches == NULL)
                        continue;

                for (uint_t cacheno = 0; cacheno < cpu_cache->fmcc_ncaches;
                    cacheno++) {
                        nvlist_free(cpu_cache->fmcc_caches[cacheno]);
                }

                umem_free(cpu_cache->fmcc_caches, sizeof (nvlist_t *) *
                    cpu_cache->fmcc_ncaches);
                cpu_cache->fmcc_caches = NULL;
        }

        if (cache->fmc_cpus != NULL) {
                umem_free(cache->fmc_cpus, sizeof (fmd_agent_cpu_cache_t) *
                    cache->fmc_ncpus);
                cache->fmc_cpus = NULL;
                cache->fmc_ncpus = 0;
        }
}

static int
fmd_agent_cache_info_pop_cpu(fmd_agent_cpu_cache_list_t *cache,
    nvlist_t *cpu_nvl, uint_t cpuno)
{
        int ret;
        char cpustr[32];
        nvlist_t **cache_nvls;
        uint_t ncache_nvls;
        fmd_agent_cpu_cache_t *cpu = &cache->fmc_cpus[cpuno];

        (void) snprintf(cpustr, sizeof (cpustr), "%u", cpuno);
        if ((ret = nvlist_lookup_nvlist_array(cpu_nvl, cpustr, &cache_nvls,
            &ncache_nvls)) != 0) {
                return (ret);
        }

        if (ncache_nvls == 0) {
                cpu->fmcc_ncaches = 0;
                cpu->fmcc_caches = NULL;
                return (0);
        }

        cpu->fmcc_caches = umem_zalloc(sizeof (nvlist_t *) * ncache_nvls,
            UMEM_DEFAULT);
        if (cpu->fmcc_caches == NULL) {
                return (errno);
        }
        cpu->fmcc_ncaches = ncache_nvls;
        for (uint_t i = 0; i < cpu->fmcc_ncaches; i++) {
                ret = nvlist_dup(cache_nvls[i], &cpu->fmcc_caches[i], 0);
                if (ret != 0) {
                        return (ret);
                }
        }

        return (0);
}

int
fmd_agent_cache_info(fmd_agent_hdl_t *hdl, fmd_agent_cpu_cache_list_t *cache)
{
        int err, ret = 0;
        uint32_t ncpus;
        nvlist_t *nvl = NULL;

        bzero(cache, sizeof (fmd_agent_cpu_cache_list_t));
        if ((err = fmd_agent_nvl_ioctl(hdl, FM_IOC_CACHE_INFO, 1, NULL,
            &nvl)) != 0) {
                ret = fmd_agent_seterrno(hdl, err);
                goto out;
        }

        if ((err = nvlist_lookup_uint32(nvl, FM_CACHE_INFO_NCPUS, &ncpus)) !=
            0) {
                ret = fmd_agent_seterrno(hdl, err);
                goto out;
        }

        cache->fmc_cpus = umem_zalloc(sizeof (fmd_agent_cpu_cache_t) * ncpus,
            UMEM_DEFAULT);
        if (cache->fmc_cpus == NULL) {
                ret = fmd_agent_seterrno(hdl, errno);
                goto out;
        }
        cache->fmc_ncpus = ncpus;
        for (uint_t i = 0; i < cache->fmc_ncpus; i++) {
                if ((err = fmd_agent_cache_info_pop_cpu(cache, nvl, i)) != 0) {
                        ret = fmd_agent_seterrno(hdl, errno);
                        goto out;
                }

        }
out:
        if (ret != 0) {
                fmd_agent_cache_info_free(hdl, cache);
        }
        nvlist_free(nvl);
        return (ret);
}