/*
 * NVMe admin command implementation.
 * Copyright (c) 2015-2016 HGST, a Western Digital Company.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 */
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/module.h>
#include <linux/rculist.h>

#include <generated/utsrelease.h>
#include <asm/unaligned.h>
#include "nvmet.h"

/*
 * This helper allows us to clear the AEN based on the RAE bit,
 * Please use this helper when processing the log pages which are
 * associated with the AEN.
 */
static inline void nvmet_clear_aen(struct nvmet_req *req, u32 aen_bit)
{
        int rae = le32_to_cpu(req->cmd->common.cdw10[0]) & 1 << 15;

        if (!rae)
                clear_bit(aen_bit, &req->sq->ctrl->aen_masked);
}

u32 nvmet_get_log_page_len(struct nvme_command *cmd)
{
        u32 len = le16_to_cpu(cmd->get_log_page.numdu);

        len <<= 16;
        len += le16_to_cpu(cmd->get_log_page.numdl);
        /* NUMD is a 0's based value */
        len += 1;
        len *= sizeof(u32);

        return len;
}

static void nvmet_execute_get_log_page_noop(struct nvmet_req *req)
{
        nvmet_req_complete(req, nvmet_zero_sgl(req, 0, req->data_len));
}

static u16 nvmet_get_smart_log_nsid(struct nvmet_req *req,
                struct nvme_smart_log *slog)
{
        struct nvmet_ns *ns;
        u64 host_reads, host_writes, data_units_read, data_units_written;

        ns = nvmet_find_namespace(req->sq->ctrl, req->cmd->get_log_page.nsid);
        if (!ns) {
                pr_err("nvmet : Could not find namespace id : %d\n",
                                le32_to_cpu(req->cmd->get_log_page.nsid));
                return NVME_SC_INVALID_NS;
        }

        /* we don't have the right data for file backed ns */
        if (!ns->bdev)
                goto out;

        host_reads = part_stat_read(ns->bdev->bd_part, ios[READ]);
        data_units_read = part_stat_read(ns->bdev->bd_part, sectors[READ]);
        host_writes = part_stat_read(ns->bdev->bd_part, ios[WRITE]);
        data_units_written = part_stat_read(ns->bdev->bd_part, sectors[WRITE]);

        put_unaligned_le64(host_reads, &slog->host_reads[0]);
        put_unaligned_le64(data_units_read, &slog->data_units_read[0]);
        put_unaligned_le64(host_writes, &slog->host_writes[0]);
        put_unaligned_le64(data_units_written, &slog->data_units_written[0]);
out:
        nvmet_put_namespace(ns);

        return NVME_SC_SUCCESS;
}

static u16 nvmet_get_smart_log_all(struct nvmet_req *req,
                struct nvme_smart_log *slog)
{
        u64 host_reads = 0, host_writes = 0;
        u64 data_units_read = 0, data_units_written = 0;
        struct nvmet_ns *ns;
        struct nvmet_ctrl *ctrl;

        ctrl = req->sq->ctrl;

        rcu_read_lock();
        list_for_each_entry_rcu(ns, &ctrl->subsys->namespaces, dev_link) {
                /* we don't have the right data for file backed ns */
                if (!ns->bdev)
                        continue;
                host_reads += part_stat_read(ns->bdev->bd_part, ios[READ]);
                data_units_read +=
                        part_stat_read(ns->bdev->bd_part, sectors[READ]);
                host_writes += part_stat_read(ns->bdev->bd_part, ios[WRITE]);
                data_units_written +=
                        part_stat_read(ns->bdev->bd_part, sectors[WRITE]);

        }
        rcu_read_unlock();

        put_unaligned_le64(host_reads, &slog->host_reads[0]);
        put_unaligned_le64(data_units_read, &slog->data_units_read[0]);
        put_unaligned_le64(host_writes, &slog->host_writes[0]);
        put_unaligned_le64(data_units_written, &slog->data_units_written[0]);

        return NVME_SC_SUCCESS;
}

static void nvmet_execute_get_log_page_smart(struct nvmet_req *req)
{
        struct nvme_smart_log *log;
        u16 status = NVME_SC_INTERNAL;

        if (req->data_len != sizeof(*log))
                goto out;

        log = kzalloc(sizeof(*log), GFP_KERNEL);
        if (!log)
                goto out;

        if (req->cmd->get_log_page.nsid == cpu_to_le32(NVME_NSID_ALL))
                status = nvmet_get_smart_log_all(req, log);
        else
                status = nvmet_get_smart_log_nsid(req, log);
        if (status)
                goto out_free_log;

        status = nvmet_copy_to_sgl(req, 0, log, sizeof(*log));
out_free_log:
        kfree(log);
out:
        nvmet_req_complete(req, status);
}

static void nvmet_execute_get_log_cmd_effects_ns(struct nvmet_req *req)
{
        u16 status = NVME_SC_INTERNAL;
        struct nvme_effects_log *log;

        log = kzalloc(sizeof(*log), GFP_KERNEL);
        if (!log)
                goto out;

        log->acs[nvme_admin_get_log_page]       = cpu_to_le32(1 << 0);
        log->acs[nvme_admin_identify]           = cpu_to_le32(1 << 0);
        log->acs[nvme_admin_abort_cmd]          = cpu_to_le32(1 << 0);
        log->acs[nvme_admin_set_features]       = cpu_to_le32(1 << 0);
        log->acs[nvme_admin_get_features]       = cpu_to_le32(1 << 0);
        log->acs[nvme_admin_async_event]        = cpu_to_le32(1 << 0);
        log->acs[nvme_admin_keep_alive]         = cpu_to_le32(1 << 0);

        log->iocs[nvme_cmd_read]                = cpu_to_le32(1 << 0);
        log->iocs[nvme_cmd_write]               = cpu_to_le32(1 << 0);
        log->iocs[nvme_cmd_flush]               = cpu_to_le32(1 << 0);
        log->iocs[nvme_cmd_dsm]                 = cpu_to_le32(1 << 0);
        log->iocs[nvme_cmd_write_zeroes]        = cpu_to_le32(1 << 0);

        status = nvmet_copy_to_sgl(req, 0, log, sizeof(*log));

        kfree(log);
out:
        nvmet_req_complete(req, status);
}

static void nvmet_execute_get_log_changed_ns(struct nvmet_req *req)
{
        struct nvmet_ctrl *ctrl = req->sq->ctrl;
        u16 status = NVME_SC_INTERNAL;
        size_t len;

        if (req->data_len != NVME_MAX_CHANGED_NAMESPACES * sizeof(__le32))
                goto out;

        mutex_lock(&ctrl->lock);
        if (ctrl->nr_changed_ns == U32_MAX)
                len = sizeof(__le32);
        else
                len = ctrl->nr_changed_ns * sizeof(__le32);
        status = nvmet_copy_to_sgl(req, 0, ctrl->changed_ns_list, len);
        if (!status)
                status = nvmet_zero_sgl(req, len, req->data_len - len);
        ctrl->nr_changed_ns = 0;
        nvmet_clear_aen(req, NVME_AEN_CFG_NS_ATTR);
        mutex_unlock(&ctrl->lock);
out:
        nvmet_req_complete(req, status);
}

static u32 nvmet_format_ana_group(struct nvmet_req *req, u32 grpid,
                struct nvme_ana_group_desc *desc)
{
        struct nvmet_ctrl *ctrl = req->sq->ctrl;
        struct nvmet_ns *ns;
        u32 count = 0;

        if (!(req->cmd->get_log_page.lsp & NVME_ANA_LOG_RGO)) {
                rcu_read_lock();
                list_for_each_entry_rcu(ns, &ctrl->subsys->namespaces, dev_link)
                        if (ns->anagrpid == grpid)
                                desc->nsids[count++] = cpu_to_le32(ns->nsid);
                rcu_read_unlock();
        }

        desc->grpid = cpu_to_le32(grpid);
        desc->nnsids = cpu_to_le32(count);
        desc->chgcnt = cpu_to_le64(nvmet_ana_chgcnt);
        desc->state = req->port->ana_state[grpid];
        memset(desc->rsvd17, 0, sizeof(desc->rsvd17));
        return sizeof(struct nvme_ana_group_desc) + count * sizeof(__le32);
}

static void nvmet_execute_get_log_page_ana(struct nvmet_req *req)
{
        struct nvme_ana_rsp_hdr hdr = { 0, };
        struct nvme_ana_group_desc *desc;
        size_t offset = sizeof(struct nvme_ana_rsp_hdr); /* start beyond hdr */
        size_t len;
        u32 grpid;
        u16 ngrps = 0;
        u16 status;

        status = NVME_SC_INTERNAL;
        desc = kmalloc(sizeof(struct nvme_ana_group_desc) +
                        NVMET_MAX_NAMESPACES * sizeof(__le32), GFP_KERNEL);
        if (!desc)
                goto out;

        down_read(&nvmet_ana_sem);
        for (grpid = 1; grpid <= NVMET_MAX_ANAGRPS; grpid++) {
                if (!nvmet_ana_group_enabled[grpid])
                        continue;
                len = nvmet_format_ana_group(req, grpid, desc);
                status = nvmet_copy_to_sgl(req, offset, desc, len);
                if (status)
                        break;
                offset += len;
                ngrps++;
        }
        for ( ; grpid <= NVMET_MAX_ANAGRPS; grpid++) {
                if (nvmet_ana_group_enabled[grpid])
                        ngrps++;
        }

        hdr.chgcnt = cpu_to_le64(nvmet_ana_chgcnt);
        hdr.ngrps = cpu_to_le16(ngrps);
        nvmet_clear_aen(req, NVME_AEN_CFG_ANA_CHANGE);
        up_read(&nvmet_ana_sem);

        kfree(desc);

        /* copy the header last once we know the number of groups */
        status = nvmet_copy_to_sgl(req, 0, &hdr, sizeof(hdr));
out:
        nvmet_req_complete(req, status);
}

static void nvmet_execute_identify_ctrl(struct nvmet_req *req)
{
        struct nvmet_ctrl *ctrl = req->sq->ctrl;
        struct nvme_id_ctrl *id;
        u16 status = 0;
        const char model[] = "Linux";

        id = kzalloc(sizeof(*id), GFP_KERNEL);
        if (!id) {
                status = NVME_SC_INTERNAL;
                goto out;
        }

        /* XXX: figure out how to assign real vendors IDs. */
        id->vid = 0;
        id->ssvid = 0;

        memset(id->sn, ' ', sizeof(id->sn));
        bin2hex(id->sn, &ctrl->subsys->serial,
                min(sizeof(ctrl->subsys->serial), sizeof(id->sn) / 2));
        memcpy_and_pad(id->mn, sizeof(id->mn), model, sizeof(model) - 1, ' ');
        memcpy_and_pad(id->fr, sizeof(id->fr),
                       UTS_RELEASE, strlen(UTS_RELEASE), ' ');

        id->rab = 6;

        /*
         * XXX: figure out how we can assign a IEEE OUI, but until then
         * the safest is to leave it as zeroes.
         */

        /* we support multiple ports, multiples hosts and ANA: */
        id->cmic = (1 << 0) | (1 << 1) | (1 << 3);

        /* no limit on data transfer sizes for now */
        id->mdts = 0;
        id->cntlid = cpu_to_le16(ctrl->cntlid);
        id->ver = cpu_to_le32(ctrl->subsys->ver);

        /* XXX: figure out what to do about RTD3R/RTD3 */
        id->oaes = cpu_to_le32(NVMET_AEN_CFG_OPTIONAL);
        id->ctratt = cpu_to_le32(1 << 0);

        id->oacs = 0;

        /*
         * We don't really have a practical limit on the number of abort
         * comands.  But we don't do anything useful for abort either, so
         * no point in allowing more abort commands than the spec requires.
         */
        id->acl = 3;

        id->aerl = NVMET_ASYNC_EVENTS - 1;

        /* first slot is read-only, only one slot supported */
        id->frmw = (1 << 0) | (1 << 1);
        id->lpa = (1 << 0) | (1 << 1) | (1 << 2);
        id->elpe = NVMET_ERROR_LOG_SLOTS - 1;
        id->npss = 0;

        /* We support keep-alive timeout in granularity of seconds */
        id->kas = cpu_to_le16(NVMET_KAS);

        id->sqes = (0x6 << 4) | 0x6;
        id->cqes = (0x4 << 4) | 0x4;

        /* no enforcement soft-limit for maxcmd - pick arbitrary high value */
        id->maxcmd = cpu_to_le16(NVMET_MAX_CMD);

        id->nn = cpu_to_le32(ctrl->subsys->max_nsid);
        id->mnan = cpu_to_le32(NVMET_MAX_NAMESPACES);
        id->oncs = cpu_to_le16(NVME_CTRL_ONCS_DSM |
                        NVME_CTRL_ONCS_WRITE_ZEROES);

        /* XXX: don't report vwc if the underlying device is write through */
        id->vwc = NVME_CTRL_VWC_PRESENT;

        /*
         * We can't support atomic writes bigger than a LBA without support
         * from the backend device.
         */
        id->awun = 0;
        id->awupf = 0;

        id->sgls = cpu_to_le32(1 << 0); /* we always support SGLs */
        if (ctrl->ops->has_keyed_sgls)
                id->sgls |= cpu_to_le32(1 << 2);
        if (req->port->inline_data_size)
                id->sgls |= cpu_to_le32(1 << 20);

        strcpy(id->subnqn, ctrl->subsys->subsysnqn);

        /* Max command capsule size is sqe + single page of in-capsule data */
        id->ioccsz = cpu_to_le32((sizeof(struct nvme_command) +
                                  req->port->inline_data_size) / 16);
        /* Max response capsule size is cqe */
        id->iorcsz = cpu_to_le32(sizeof(struct nvme_completion) / 16);

        id->msdbd = ctrl->ops->msdbd;

        id->anacap = (1 << 0) | (1 << 1) | (1 << 2) | (1 << 3) | (1 << 4);
        id->anatt = 10; /* random value */
        id->anagrpmax = cpu_to_le32(NVMET_MAX_ANAGRPS);
        id->nanagrpid = cpu_to_le32(NVMET_MAX_ANAGRPS);

        /*
         * Meh, we don't really support any power state.  Fake up the same
         * values that qemu does.
         */
        id->psd[0].max_power = cpu_to_le16(0x9c4);
        id->psd[0].entry_lat = cpu_to_le32(0x10);
        id->psd[0].exit_lat = cpu_to_le32(0x4);

        id->nwpc = 1 << 0; /* write protect and no write protect */

        status = nvmet_copy_to_sgl(req, 0, id, sizeof(*id));

        kfree(id);
out:
        nvmet_req_complete(req, status);
}

static void nvmet_execute_identify_ns(struct nvmet_req *req)
{
        struct nvmet_ns *ns;
        struct nvme_id_ns *id;
        u16 status = 0;

        if (le32_to_cpu(req->cmd->identify.nsid) == NVME_NSID_ALL) {
                status = NVME_SC_INVALID_NS | NVME_SC_DNR;
                goto out;
        }

        id = kzalloc(sizeof(*id), GFP_KERNEL);
        if (!id) {
                status = NVME_SC_INTERNAL;
                goto out;
        }

        /* return an all zeroed buffer if we can't find an active namespace */
        ns = nvmet_find_namespace(req->sq->ctrl, req->cmd->identify.nsid);
        if (!ns)
                goto done;

        /*
         * nuse = ncap = nsze isn't always true, but we have no way to find
         * that out from the underlying device.
         */
        id->ncap = id->nsze = cpu_to_le64(ns->size >> ns->blksize_shift);
        switch (req->port->ana_state[ns->anagrpid]) {
        case NVME_ANA_INACCESSIBLE:
        case NVME_ANA_PERSISTENT_LOSS:
                break;
        default:
                id->nuse = id->nsze;
                break;
        }

        /*
         * We just provide a single LBA format that matches what the
         * underlying device reports.
         */
        id->nlbaf = 0;
        id->flbas = 0;

        /*
         * Our namespace might always be shared.  Not just with other
         * controllers, but also with any other user of the block device.
         */
        id->nmic = (1 << 0);
        id->anagrpid = cpu_to_le32(ns->anagrpid);

        memcpy(&id->nguid, &ns->nguid, sizeof(id->nguid));

        id->lbaf[0].ds = ns->blksize_shift;

        if (ns->readonly)
                id->nsattr |= (1 << 0);
        nvmet_put_namespace(ns);
done:
        status = nvmet_copy_to_sgl(req, 0, id, sizeof(*id));
        kfree(id);
out:
        nvmet_req_complete(req, status);
}

static void nvmet_execute_identify_nslist(struct nvmet_req *req)
{
        static const int buf_size = NVME_IDENTIFY_DATA_SIZE;
        struct nvmet_ctrl *ctrl = req->sq->ctrl;
        struct nvmet_ns *ns;
        u32 min_nsid = le32_to_cpu(req->cmd->identify.nsid);
        __le32 *list;
        u16 status = 0;
        int i = 0;

        list = kzalloc(buf_size, GFP_KERNEL);
        if (!list) {
                status = NVME_SC_INTERNAL;
                goto out;
        }

        rcu_read_lock();
        list_for_each_entry_rcu(ns, &ctrl->subsys->namespaces, dev_link) {
                if (ns->nsid <= min_nsid)
                        continue;
                list[i++] = cpu_to_le32(ns->nsid);
                if (i == buf_size / sizeof(__le32))
                        break;
        }
        rcu_read_unlock();

        status = nvmet_copy_to_sgl(req, 0, list, buf_size);

        kfree(list);
out:
        nvmet_req_complete(req, status);
}

static u16 nvmet_copy_ns_identifier(struct nvmet_req *req, u8 type, u8 len,
                                    void *id, off_t *off)
{
        struct nvme_ns_id_desc desc = {
                .nidt = type,
                .nidl = len,
        };
        u16 status;

        status = nvmet_copy_to_sgl(req, *off, &desc, sizeof(desc));
        if (status)
                return status;
        *off += sizeof(desc);

        status = nvmet_copy_to_sgl(req, *off, id, len);
        if (status)
                return status;
        *off += len;

        return 0;
}

static void nvmet_execute_identify_desclist(struct nvmet_req *req)
{
        struct nvmet_ns *ns;
        u16 status = 0;
        off_t off = 0;

        ns = nvmet_find_namespace(req->sq->ctrl, req->cmd->identify.nsid);
        if (!ns) {
                status = NVME_SC_INVALID_NS | NVME_SC_DNR;
                goto out;
        }

        if (memchr_inv(&ns->uuid, 0, sizeof(ns->uuid))) {
                status = nvmet_copy_ns_identifier(req, NVME_NIDT_UUID,
                                                  NVME_NIDT_UUID_LEN,
                                                  &ns->uuid, &off);
                if (status)
                        goto out_put_ns;
        }
        if (memchr_inv(ns->nguid, 0, sizeof(ns->nguid))) {
                status = nvmet_copy_ns_identifier(req, NVME_NIDT_NGUID,
                                                  NVME_NIDT_NGUID_LEN,
                                                  &ns->nguid, &off);
                if (status)
                        goto out_put_ns;
        }

        if (sg_zero_buffer(req->sg, req->sg_cnt, NVME_IDENTIFY_DATA_SIZE - off,
                        off) != NVME_IDENTIFY_DATA_SIZE - off)
                status = NVME_SC_INTERNAL | NVME_SC_DNR;
out_put_ns:
        nvmet_put_namespace(ns);
out:
        nvmet_req_complete(req, status);
}

/*
 * A "minimum viable" abort implementation: the command is mandatory in the
 * spec, but we are not required to do any useful work.  We couldn't really
 * do a useful abort, so don't bother even with waiting for the command
 * to be exectuted and return immediately telling the command to abort
 * wasn't found.
 */
static void nvmet_execute_abort(struct nvmet_req *req)
{
        nvmet_set_result(req, 1);
        nvmet_req_complete(req, 0);
}

static u16 nvmet_write_protect_flush_sync(struct nvmet_req *req)
{
        u16 status;

        if (req->ns->file)
                status = nvmet_file_flush(req);
        else
                status = nvmet_bdev_flush(req);

        if (status)
                pr_err("write protect flush failed nsid: %u\n", req->ns->nsid);
        return status;
}

static u16 nvmet_set_feat_write_protect(struct nvmet_req *req)
{
        u32 write_protect = le32_to_cpu(req->cmd->common.cdw10[1]);
        struct nvmet_subsys *subsys = req->sq->ctrl->subsys;
        u16 status = NVME_SC_FEATURE_NOT_CHANGEABLE;

        req->ns = nvmet_find_namespace(req->sq->ctrl, req->cmd->rw.nsid);
        if (unlikely(!req->ns))
                return status;

        mutex_lock(&subsys->lock);
        switch (write_protect) {
        case NVME_NS_WRITE_PROTECT:
                req->ns->readonly = true;
                status = nvmet_write_protect_flush_sync(req);
                if (status)
                        req->ns->readonly = false;
                break;
        case NVME_NS_NO_WRITE_PROTECT:
                req->ns->readonly = false;
                status = 0;
                break;
        default:
                break;
        }

        if (!status)
                nvmet_ns_changed(subsys, req->ns->nsid);
        mutex_unlock(&subsys->lock);
        return status;
}

static void nvmet_execute_set_features(struct nvmet_req *req)
{
        struct nvmet_subsys *subsys = req->sq->ctrl->subsys;
        u32 cdw10 = le32_to_cpu(req->cmd->common.cdw10[0]);
        u32 val32;
        u16 status = 0;

        switch (cdw10 & 0xff) {
        case NVME_FEAT_NUM_QUEUES:
                nvmet_set_result(req,
                        (subsys->max_qid - 1) | ((subsys->max_qid - 1) << 16));
                break;
        case NVME_FEAT_KATO:
                val32 = le32_to_cpu(req->cmd->common.cdw10[1]);
                req->sq->ctrl->kato = DIV_ROUND_UP(val32, 1000);
                nvmet_set_result(req, req->sq->ctrl->kato);
                break;
        case NVME_FEAT_ASYNC_EVENT:
                val32 = le32_to_cpu(req->cmd->common.cdw10[1]);
                if (val32 & ~NVMET_AEN_CFG_ALL) {
                        status = NVME_SC_INVALID_FIELD | NVME_SC_DNR;
                        break;
                }

                WRITE_ONCE(req->sq->ctrl->aen_enabled, val32);
                nvmet_set_result(req, val32);
                break;
        case NVME_FEAT_HOST_ID:
                status = NVME_SC_CMD_SEQ_ERROR | NVME_SC_DNR;
                break;
        case NVME_FEAT_WRITE_PROTECT:
                status = nvmet_set_feat_write_protect(req);
                break;
        default:
                status = NVME_SC_INVALID_FIELD | NVME_SC_DNR;
                break;
        }

        nvmet_req_complete(req, status);
}

static u16 nvmet_get_feat_write_protect(struct nvmet_req *req)
{
        struct nvmet_subsys *subsys = req->sq->ctrl->subsys;
        u32 result;

        req->ns = nvmet_find_namespace(req->sq->ctrl, req->cmd->common.nsid);
        if (!req->ns)
                return NVME_SC_INVALID_NS | NVME_SC_DNR;

        mutex_lock(&subsys->lock);
        if (req->ns->readonly == true)
                result = NVME_NS_WRITE_PROTECT;
        else
                result = NVME_NS_NO_WRITE_PROTECT;
        nvmet_set_result(req, result);
        mutex_unlock(&subsys->lock);

        return 0;
}

static void nvmet_execute_get_features(struct nvmet_req *req)
{
        struct nvmet_subsys *subsys = req->sq->ctrl->subsys;
        u32 cdw10 = le32_to_cpu(req->cmd->common.cdw10[0]);
        u16 status = 0;

        switch (cdw10 & 0xff) {
        /*
         * These features are mandatory in the spec, but we don't
         * have a useful way to implement them.  We'll eventually
         * need to come up with some fake values for these.
         */
#if 0
        case NVME_FEAT_ARBITRATION:
                break;
        case NVME_FEAT_POWER_MGMT:
                break;
        case NVME_FEAT_TEMP_THRESH:
                break;
        case NVME_FEAT_ERR_RECOVERY:
                break;
        case NVME_FEAT_IRQ_COALESCE:
                break;
        case NVME_FEAT_IRQ_CONFIG:
                break;
        case NVME_FEAT_WRITE_ATOMIC:
                break;
#endif
        case NVME_FEAT_ASYNC_EVENT:
                nvmet_set_result(req, READ_ONCE(req->sq->ctrl->aen_enabled));
                break;
        case NVME_FEAT_VOLATILE_WC:
                nvmet_set_result(req, 1);
                break;
        case NVME_FEAT_NUM_QUEUES:
                nvmet_set_result(req,
                        (subsys->max_qid-1) | ((subsys->max_qid-1) << 16));
                break;
        case NVME_FEAT_KATO:
                nvmet_set_result(req, req->sq->ctrl->kato * 1000);
                break;
        case NVME_FEAT_HOST_ID:
                /* need 128-bit host identifier flag */
                if (!(req->cmd->common.cdw10[1] & cpu_to_le32(1 << 0))) {
                        status = NVME_SC_INVALID_FIELD | NVME_SC_DNR;
                        break;
                }

                status = nvmet_copy_to_sgl(req, 0, &req->sq->ctrl->hostid,
                                sizeof(req->sq->ctrl->hostid));
                break;
        case NVME_FEAT_WRITE_PROTECT:
                status = nvmet_get_feat_write_protect(req);
                break;
        default:
                status = NVME_SC_INVALID_FIELD | NVME_SC_DNR;
                break;
        }

        nvmet_req_complete(req, status);
}

static void nvmet_execute_async_event(struct nvmet_req *req)
{
        struct nvmet_ctrl *ctrl = req->sq->ctrl;

        mutex_lock(&ctrl->lock);
        if (ctrl->nr_async_event_cmds >= NVMET_ASYNC_EVENTS) {
                mutex_unlock(&ctrl->lock);
                nvmet_req_complete(req, NVME_SC_ASYNC_LIMIT | NVME_SC_DNR);
                return;
        }
        ctrl->async_event_cmds[ctrl->nr_async_event_cmds++] = req;
        mutex_unlock(&ctrl->lock);

        schedule_work(&ctrl->async_event_work);
}

static void nvmet_execute_keep_alive(struct nvmet_req *req)
{
        struct nvmet_ctrl *ctrl = req->sq->ctrl;

        pr_debug("ctrl %d update keep-alive timer for %d secs\n",
                ctrl->cntlid, ctrl->kato);

        mod_delayed_work(system_wq, &ctrl->ka_work, ctrl->kato * HZ);
        nvmet_req_complete(req, 0);
}

u16 nvmet_parse_admin_cmd(struct nvmet_req *req)
{
        struct nvme_command *cmd = req->cmd;
        u16 ret;

        ret = nvmet_check_ctrl_status(req, cmd);
        if (unlikely(ret))
                return ret;

        switch (cmd->common.opcode) {
        case nvme_admin_get_log_page:
                req->data_len = nvmet_get_log_page_len(cmd);

                switch (cmd->get_log_page.lid) {
                case NVME_LOG_ERROR:
                        /*
                         * We currently never set the More bit in the status
                         * field, so all error log entries are invalid and can
                         * be zeroed out.  This is called a minum viable
                         * implementation (TM) of this mandatory log page.
                         */
                        req->execute = nvmet_execute_get_log_page_noop;
                        return 0;
                case NVME_LOG_SMART:
                        req->execute = nvmet_execute_get_log_page_smart;
                        return 0;
                case NVME_LOG_FW_SLOT:
                        /*
                         * We only support a single firmware slot which always
                         * is active, so we can zero out the whole firmware slot
                         * log and still claim to fully implement this mandatory
                         * log page.
                         */
                        req->execute = nvmet_execute_get_log_page_noop;
                        return 0;
                case NVME_LOG_CHANGED_NS:
                        req->execute = nvmet_execute_get_log_changed_ns;
                        return 0;
                case NVME_LOG_CMD_EFFECTS:
                        req->execute = nvmet_execute_get_log_cmd_effects_ns;
                        return 0;
                case NVME_LOG_ANA:
                        req->execute = nvmet_execute_get_log_page_ana;
                        return 0;
                }
                break;
        case nvme_admin_identify:
                req->data_len = NVME_IDENTIFY_DATA_SIZE;
                switch (cmd->identify.cns) {
                case NVME_ID_CNS_NS:
                        req->execute = nvmet_execute_identify_ns;
                        return 0;
                case NVME_ID_CNS_CTRL:
                        req->execute = nvmet_execute_identify_ctrl;
                        return 0;
                case NVME_ID_CNS_NS_ACTIVE_LIST:
                        req->execute = nvmet_execute_identify_nslist;
                        return 0;
                case NVME_ID_CNS_NS_DESC_LIST:
                        req->execute = nvmet_execute_identify_desclist;
                        return 0;
                }
                break;
        case nvme_admin_abort_cmd:
                req->execute = nvmet_execute_abort;
                req->data_len = 0;
                return 0;
        case nvme_admin_set_features:
                req->execute = nvmet_execute_set_features;
                req->data_len = 0;
                return 0;
        case nvme_admin_get_features:
                req->execute = nvmet_execute_get_features;
                req->data_len = 0;
                return 0;
        case nvme_admin_async_event:
                req->execute = nvmet_execute_async_event;
                req->data_len = 0;
                return 0;
        case nvme_admin_keep_alive:
                req->execute = nvmet_execute_keep_alive;
                req->data_len = 0;
                return 0;
        }

        pr_err("unhandled cmd %d on qid %d\n", cmd->common.opcode,
               req->sq->qid);
        return NVME_SC_INVALID_OPCODE | NVME_SC_DNR;
}