// SPDX-License-Identifier: GPL-2.0
/*
 * NVMe ZNS-ZBD command implementation.
 * Copyright (C) 2021 Western Digital Corporation or its affiliates.
 */
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/nvme.h>
#include <linux/blkdev.h>
#include "nvmet.h"

/*
 * We set the Memory Page Size Minimum (MPSMIN) for target controller to 0
 * which gets added by 12 in the nvme_enable_ctrl() which results in 2^12 = 4k
 * as page_shift value. When calculating the ZASL use shift by 12.
 */
#define NVMET_MPSMIN_SHIFT      12

static inline u8 nvmet_zasl(unsigned int zone_append_sects)
{
        /*
         * Zone Append Size Limit (zasl) is expressed as a power of 2 value
         * with the minimum memory page size (i.e. 12) as unit.
         */
        return ilog2(zone_append_sects >> (NVMET_MPSMIN_SHIFT - 9));
}

static int validate_conv_zones_cb(struct blk_zone *z,
                                  unsigned int i, void *data)
{
        if (z->type == BLK_ZONE_TYPE_CONVENTIONAL)
                return -EOPNOTSUPP;
        return 0;
}

bool nvmet_bdev_zns_enable(struct nvmet_ns *ns)
{
        u8 zasl = nvmet_zasl(bdev_max_zone_append_sectors(ns->bdev));
        struct gendisk *bd_disk = ns->bdev->bd_disk;
        int ret;

        if (ns->subsys->zasl) {
                if (ns->subsys->zasl > zasl)
                        return false;
        }
        ns->subsys->zasl = zasl;

        /*
         * Generic zoned block devices may have a smaller last zone which is
         * not supported by ZNS. Exclude zoned drives that have such smaller
         * last zone.
         */
        if (get_capacity(bd_disk) & (bdev_zone_sectors(ns->bdev) - 1))
                return false;
        /*
         * ZNS does not define a conventional zone type. Use report zones
         * to detect if the device has conventional zones and reject it if
         * it does.
         */
        ret = blkdev_report_zones(ns->bdev, 0, bdev_nr_zones(ns->bdev),
                                  validate_conv_zones_cb, NULL);
        if (ret < 0)
                return false;

        ns->blksize_shift = blksize_bits(bdev_logical_block_size(ns->bdev));

        return true;
}

void nvmet_execute_identify_ctrl_zns(struct nvmet_req *req)
{
        u8 zasl = req->sq->ctrl->subsys->zasl;
        struct nvmet_ctrl *ctrl = req->sq->ctrl;
        struct nvme_id_ctrl_zns *id;
        u16 status;

        id = kzalloc_obj(*id);
        if (!id) {
                status = NVME_SC_INTERNAL;
                goto out;
        }

        if (ctrl->ops->get_mdts)
                id->zasl = min_t(u8, ctrl->ops->get_mdts(ctrl), zasl);
        else
                id->zasl = zasl;

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

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

void nvmet_execute_identify_ns_zns(struct nvmet_req *req)
{
        struct nvme_id_ns_zns *id_zns = NULL;
        u64 zsze;
        u16 status;
        u32 mar, mor;

        if (le32_to_cpu(req->cmd->identify.nsid) == NVME_NSID_ALL) {
                req->error_loc = offsetof(struct nvme_identify, nsid);
                status = NVME_SC_INVALID_NS | NVME_STATUS_DNR;
                goto out;
        }

        id_zns = kzalloc_obj(*id_zns);
        if (!id_zns) {
                status = NVME_SC_INTERNAL;
                goto out;
        }

        status = nvmet_req_find_ns(req);
        if (status)
                goto done;

        if (nvmet_ns_revalidate(req->ns)) {
                mutex_lock(&req->ns->subsys->lock);
                nvmet_ns_changed(req->ns->subsys, req->ns->nsid);
                mutex_unlock(&req->ns->subsys->lock);
        }

        if (!bdev_is_zoned(req->ns->bdev)) {
                status = NVME_SC_INVALID_FIELD | NVME_STATUS_DNR;
                req->error_loc = offsetof(struct nvme_identify, nsid);
                goto out;
        }

        zsze = (bdev_zone_sectors(req->ns->bdev) << 9) >>
                                        req->ns->blksize_shift;
        id_zns->lbafe[0].zsze = cpu_to_le64(zsze);

        mor = bdev_max_open_zones(req->ns->bdev);
        if (!mor)
                mor = U32_MAX;
        else
                mor--;
        id_zns->mor = cpu_to_le32(mor);

        mar = bdev_max_active_zones(req->ns->bdev);
        if (!mar)
                mar = U32_MAX;
        else
                mar--;
        id_zns->mar = cpu_to_le32(mar);

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

static u16 nvmet_bdev_validate_zone_mgmt_recv(struct nvmet_req *req)
{
        sector_t sect = nvmet_lba_to_sect(req->ns, req->cmd->zmr.slba);
        u32 out_bufsize = (le32_to_cpu(req->cmd->zmr.numd) + 1) << 2;

        if (sect >= get_capacity(req->ns->bdev->bd_disk)) {
                req->error_loc = offsetof(struct nvme_zone_mgmt_recv_cmd, slba);
                return NVME_SC_LBA_RANGE | NVME_STATUS_DNR;
        }

        if (out_bufsize < sizeof(struct nvme_zone_report)) {
                req->error_loc = offsetof(struct nvme_zone_mgmt_recv_cmd, numd);
                return NVME_SC_INVALID_FIELD | NVME_STATUS_DNR;
        }

        if (req->cmd->zmr.zra != NVME_ZRA_ZONE_REPORT) {
                req->error_loc = offsetof(struct nvme_zone_mgmt_recv_cmd, zra);
                return NVME_SC_INVALID_FIELD | NVME_STATUS_DNR;
        }

        switch (req->cmd->zmr.pr) {
        case 0:
        case 1:
                break;
        default:
                req->error_loc = offsetof(struct nvme_zone_mgmt_recv_cmd, pr);
                return NVME_SC_INVALID_FIELD | NVME_STATUS_DNR;
        }

        switch (req->cmd->zmr.zrasf) {
        case NVME_ZRASF_ZONE_REPORT_ALL:
        case NVME_ZRASF_ZONE_STATE_EMPTY:
        case NVME_ZRASF_ZONE_STATE_IMP_OPEN:
        case NVME_ZRASF_ZONE_STATE_EXP_OPEN:
        case NVME_ZRASF_ZONE_STATE_CLOSED:
        case NVME_ZRASF_ZONE_STATE_FULL:
        case NVME_ZRASF_ZONE_STATE_READONLY:
        case NVME_ZRASF_ZONE_STATE_OFFLINE:
                break;
        default:
                req->error_loc =
                        offsetof(struct nvme_zone_mgmt_recv_cmd, zrasf);
                return NVME_SC_INVALID_FIELD | NVME_STATUS_DNR;
        }

        return NVME_SC_SUCCESS;
}

struct nvmet_report_zone_data {
        struct nvmet_req *req;
        u64 out_buf_offset;
        u64 out_nr_zones;
        u64 nr_zones;
        u8 zrasf;
};

static int nvmet_bdev_report_zone_cb(struct blk_zone *z, unsigned i, void *d)
{
        static const unsigned int nvme_zrasf_to_blk_zcond[] = {
                [NVME_ZRASF_ZONE_STATE_EMPTY]    = BLK_ZONE_COND_EMPTY,
                [NVME_ZRASF_ZONE_STATE_IMP_OPEN] = BLK_ZONE_COND_IMP_OPEN,
                [NVME_ZRASF_ZONE_STATE_EXP_OPEN] = BLK_ZONE_COND_EXP_OPEN,
                [NVME_ZRASF_ZONE_STATE_CLOSED]   = BLK_ZONE_COND_CLOSED,
                [NVME_ZRASF_ZONE_STATE_READONLY] = BLK_ZONE_COND_READONLY,
                [NVME_ZRASF_ZONE_STATE_FULL]     = BLK_ZONE_COND_FULL,
                [NVME_ZRASF_ZONE_STATE_OFFLINE]  = BLK_ZONE_COND_OFFLINE,
        };
        struct nvmet_report_zone_data *rz = d;

        if (rz->zrasf != NVME_ZRASF_ZONE_REPORT_ALL &&
            z->cond != nvme_zrasf_to_blk_zcond[rz->zrasf])
                return 0;

        if (rz->nr_zones < rz->out_nr_zones) {
                struct nvme_zone_descriptor zdesc = { };
                u16 status;

                zdesc.zcap = nvmet_sect_to_lba(rz->req->ns, z->capacity);
                zdesc.zslba = nvmet_sect_to_lba(rz->req->ns, z->start);
                zdesc.wp = nvmet_sect_to_lba(rz->req->ns, z->wp);
                zdesc.za = z->reset ? 1 << 2 : 0;
                zdesc.zs = z->cond << 4;
                zdesc.zt = z->type;

                status = nvmet_copy_to_sgl(rz->req, rz->out_buf_offset, &zdesc,
                                           sizeof(zdesc));
                if (status)
                        return -EINVAL;

                rz->out_buf_offset += sizeof(zdesc);
        }

        rz->nr_zones++;

        return 0;
}

static unsigned long nvmet_req_nr_zones_from_slba(struct nvmet_req *req)
{
        unsigned int sect = nvmet_lba_to_sect(req->ns, req->cmd->zmr.slba);

        return bdev_nr_zones(req->ns->bdev) - bdev_zone_no(req->ns->bdev, sect);
}

static unsigned long get_nr_zones_from_buf(struct nvmet_req *req, u32 bufsize)
{
        if (bufsize <= sizeof(struct nvme_zone_report))
                return 0;

        return (bufsize - sizeof(struct nvme_zone_report)) /
                sizeof(struct nvme_zone_descriptor);
}

static void nvmet_bdev_zone_zmgmt_recv_work(struct work_struct *w)
{
        struct nvmet_req *req = container_of(w, struct nvmet_req, z.zmgmt_work);
        sector_t start_sect = nvmet_lba_to_sect(req->ns, req->cmd->zmr.slba);
        unsigned long req_slba_nr_zones = nvmet_req_nr_zones_from_slba(req);
        u32 out_bufsize = (le32_to_cpu(req->cmd->zmr.numd) + 1) << 2;
        __le64 nr_zones;
        u16 status;
        int ret;
        struct nvmet_report_zone_data rz_data = {
                .out_nr_zones = get_nr_zones_from_buf(req, out_bufsize),
                /* leave the place for report zone header */
                .out_buf_offset = sizeof(struct nvme_zone_report),
                .zrasf = req->cmd->zmr.zrasf,
                .nr_zones = 0,
                .req = req,
        };

        status = nvmet_bdev_validate_zone_mgmt_recv(req);
        if (status)
                goto out;

        if (!req_slba_nr_zones) {
                status = NVME_SC_SUCCESS;
                goto out;
        }

        ret = blkdev_report_zones(req->ns->bdev, start_sect, req_slba_nr_zones,
                                 nvmet_bdev_report_zone_cb, &rz_data);
        if (ret < 0) {
                status = NVME_SC_INTERNAL;
                goto out;
        }

        /*
         * When partial bit is set nr_zones must indicate the number of zone
         * descriptors actually transferred.
         */
        if (req->cmd->zmr.pr)
                rz_data.nr_zones = min(rz_data.nr_zones, rz_data.out_nr_zones);

        nr_zones = cpu_to_le64(rz_data.nr_zones);
        status = nvmet_copy_to_sgl(req, 0, &nr_zones, sizeof(nr_zones));

out:
        nvmet_req_complete(req, status);
}

void nvmet_bdev_execute_zone_mgmt_recv(struct nvmet_req *req)
{
        INIT_WORK(&req->z.zmgmt_work, nvmet_bdev_zone_zmgmt_recv_work);
        queue_work(zbd_wq, &req->z.zmgmt_work);
}

static inline enum req_op zsa_req_op(u8 zsa)
{
        switch (zsa) {
        case NVME_ZONE_OPEN:
                return REQ_OP_ZONE_OPEN;
        case NVME_ZONE_CLOSE:
                return REQ_OP_ZONE_CLOSE;
        case NVME_ZONE_FINISH:
                return REQ_OP_ZONE_FINISH;
        case NVME_ZONE_RESET:
                return REQ_OP_ZONE_RESET;
        default:
                return REQ_OP_LAST;
        }
}

static u16 blkdev_zone_mgmt_errno_to_nvme_status(int ret)
{
        switch (ret) {
        case 0:
                return NVME_SC_SUCCESS;
        case -EINVAL:
        case -EIO:
                return NVME_SC_ZONE_INVALID_TRANSITION | NVME_STATUS_DNR;
        default:
                return NVME_SC_INTERNAL;
        }
}

struct nvmet_zone_mgmt_send_all_data {
        unsigned long *zbitmap;
        struct nvmet_req *req;
};

static int zmgmt_send_scan_cb(struct blk_zone *z, unsigned i, void *d)
{
        struct nvmet_zone_mgmt_send_all_data *data = d;

        switch (zsa_req_op(data->req->cmd->zms.zsa)) {
        case REQ_OP_ZONE_OPEN:
                switch (z->cond) {
                case BLK_ZONE_COND_CLOSED:
                        break;
                default:
                        return 0;
                }
                break;
        case REQ_OP_ZONE_CLOSE:
                switch (z->cond) {
                case BLK_ZONE_COND_IMP_OPEN:
                case BLK_ZONE_COND_EXP_OPEN:
                        break;
                default:
                        return 0;
                }
                break;
        case REQ_OP_ZONE_FINISH:
                switch (z->cond) {
                case BLK_ZONE_COND_IMP_OPEN:
                case BLK_ZONE_COND_EXP_OPEN:
                case BLK_ZONE_COND_CLOSED:
                        break;
                default:
                        return 0;
                }
                break;
        default:
                return -EINVAL;
        }

        set_bit(i, data->zbitmap);

        return 0;
}

static u16 nvmet_bdev_zone_mgmt_emulate_all(struct nvmet_req *req)
{
        struct block_device *bdev = req->ns->bdev;
        unsigned int nr_zones = bdev_nr_zones(bdev);
        struct bio *bio = NULL;
        sector_t sector = 0;
        int ret;
        struct nvmet_zone_mgmt_send_all_data d = {
                .req = req,
        };

        d.zbitmap = kcalloc_node(BITS_TO_LONGS(nr_zones), sizeof(*(d.zbitmap)),
                                 GFP_NOIO, bdev->bd_disk->node_id);
        if (!d.zbitmap) {
                ret = -ENOMEM;
                goto out;
        }

        /* Scan and build bitmap of the eligible zones */
        ret = blkdev_report_zones(bdev, 0, nr_zones, zmgmt_send_scan_cb, &d);
        if (ret != nr_zones) {
                if (ret > 0)
                        ret = -EIO;
                goto out;
        } else {
                /* We scanned all the zones */
                ret = 0;
        }

        while (sector < bdev_nr_sectors(bdev)) {
                if (test_bit(disk_zone_no(bdev->bd_disk, sector), d.zbitmap)) {
                        bio = blk_next_bio(bio, bdev, 0,
                                zsa_req_op(req->cmd->zms.zsa) | REQ_SYNC,
                                GFP_KERNEL);
                        bio->bi_iter.bi_sector = sector;
                        /* This may take a while, so be nice to others */
                        cond_resched();
                }
                sector += bdev_zone_sectors(bdev);
        }

        if (bio) {
                ret = submit_bio_wait(bio);
                bio_put(bio);
        }

out:
        kfree(d.zbitmap);

        return blkdev_zone_mgmt_errno_to_nvme_status(ret);
}

static u16 nvmet_bdev_execute_zmgmt_send_all(struct nvmet_req *req)
{
        int ret;

        switch (zsa_req_op(req->cmd->zms.zsa)) {
        case REQ_OP_ZONE_RESET:
                ret = blkdev_zone_mgmt(req->ns->bdev, REQ_OP_ZONE_RESET, 0,
                                       get_capacity(req->ns->bdev->bd_disk));
                if (ret < 0)
                        return blkdev_zone_mgmt_errno_to_nvme_status(ret);
                break;
        case REQ_OP_ZONE_OPEN:
        case REQ_OP_ZONE_CLOSE:
        case REQ_OP_ZONE_FINISH:
                return nvmet_bdev_zone_mgmt_emulate_all(req);
        default:
                /* this is needed to quiet compiler warning */
                req->error_loc = offsetof(struct nvme_zone_mgmt_send_cmd, zsa);
                return NVME_SC_INVALID_FIELD | NVME_STATUS_DNR;
        }

        return NVME_SC_SUCCESS;
}

static void nvmet_bdev_zmgmt_send_work(struct work_struct *w)
{
        struct nvmet_req *req = container_of(w, struct nvmet_req, z.zmgmt_work);
        sector_t sect = nvmet_lba_to_sect(req->ns, req->cmd->zms.slba);
        enum req_op op = zsa_req_op(req->cmd->zms.zsa);
        struct block_device *bdev = req->ns->bdev;
        sector_t zone_sectors = bdev_zone_sectors(bdev);
        u16 status = NVME_SC_SUCCESS;
        int ret;

        if (op == REQ_OP_LAST) {
                req->error_loc = offsetof(struct nvme_zone_mgmt_send_cmd, zsa);
                status = NVME_SC_ZONE_INVALID_TRANSITION | NVME_STATUS_DNR;
                goto out;
        }

        /* when select all bit is set slba field is ignored */
        if (req->cmd->zms.select_all) {
                status = nvmet_bdev_execute_zmgmt_send_all(req);
                goto out;
        }

        if (sect >= get_capacity(bdev->bd_disk)) {
                req->error_loc = offsetof(struct nvme_zone_mgmt_send_cmd, slba);
                status = NVME_SC_LBA_RANGE | NVME_STATUS_DNR;
                goto out;
        }

        if (sect & (zone_sectors - 1)) {
                req->error_loc = offsetof(struct nvme_zone_mgmt_send_cmd, slba);
                status = NVME_SC_INVALID_FIELD | NVME_STATUS_DNR;
                goto out;
        }

        ret = blkdev_zone_mgmt(bdev, op, sect, zone_sectors);
        if (ret < 0)
                status = blkdev_zone_mgmt_errno_to_nvme_status(ret);

out:
        nvmet_req_complete(req, status);
}

void nvmet_bdev_execute_zone_mgmt_send(struct nvmet_req *req)
{
        INIT_WORK(&req->z.zmgmt_work, nvmet_bdev_zmgmt_send_work);
        queue_work(zbd_wq, &req->z.zmgmt_work);
}

static void nvmet_bdev_zone_append_bio_done(struct bio *bio)
{
        struct nvmet_req *req = bio->bi_private;

        if (bio->bi_status == BLK_STS_OK) {
                req->cqe->result.u64 =
                        nvmet_sect_to_lba(req->ns, bio->bi_iter.bi_sector);
        }

        nvmet_req_complete(req, blk_to_nvme_status(req, bio->bi_status));
        nvmet_req_bio_put(req, bio);
}

void nvmet_bdev_execute_zone_append(struct nvmet_req *req)
{
        sector_t sect = nvmet_lba_to_sect(req->ns, req->cmd->rw.slba);
        const blk_opf_t opf = REQ_OP_ZONE_APPEND | REQ_SYNC | REQ_IDLE;
        u16 status = NVME_SC_SUCCESS;
        unsigned int total_len = 0;
        struct scatterlist *sg;
        u32 data_len = nvmet_rw_data_len(req);
        struct bio *bio;
        int sg_cnt;

        /* Request is completed on len mismatch in nvmet_check_transfer_len() */
        if (!nvmet_check_transfer_len(req, nvmet_rw_data_len(req)))
                return;

        if (data_len >
            bdev_max_zone_append_sectors(req->ns->bdev) << SECTOR_SHIFT) {
                req->error_loc = offsetof(struct nvme_rw_command, length);
                status = NVME_SC_INVALID_FIELD | NVME_STATUS_DNR;
                goto out;
        }

        if (!req->sg_cnt) {
                nvmet_req_complete(req, 0);
                return;
        }

        if (sect >= get_capacity(req->ns->bdev->bd_disk)) {
                req->error_loc = offsetof(struct nvme_rw_command, slba);
                status = NVME_SC_LBA_RANGE | NVME_STATUS_DNR;
                goto out;
        }

        if (sect & (bdev_zone_sectors(req->ns->bdev) - 1)) {
                req->error_loc = offsetof(struct nvme_rw_command, slba);
                status = NVME_SC_INVALID_FIELD | NVME_STATUS_DNR;
                goto out;
        }

        if (nvmet_use_inline_bvec(req)) {
                bio = &req->z.inline_bio;
                bio_init(bio, req->ns->bdev, req->inline_bvec,
                         ARRAY_SIZE(req->inline_bvec), opf);
        } else {
                bio = bio_alloc(req->ns->bdev, req->sg_cnt, opf, GFP_KERNEL);
        }

        bio->bi_end_io = nvmet_bdev_zone_append_bio_done;
        bio->bi_iter.bi_sector = sect;
        bio->bi_private = req;
        if (req->cmd->rw.control & cpu_to_le16(NVME_RW_FUA))
                bio->bi_opf |= REQ_FUA;

        for_each_sg(req->sg, sg, req->sg_cnt, sg_cnt) {
                unsigned int len = sg->length;

                if (bio_add_page(bio, sg_page(sg), len, sg->offset) != len) {
                        status = NVME_SC_INTERNAL;
                        goto out_put_bio;
                }
                total_len += len;
        }

        if (total_len != data_len) {
                status = NVME_SC_INTERNAL | NVME_STATUS_DNR;
                goto out_put_bio;
        }

        submit_bio(bio);
        return;

out_put_bio:
        nvmet_req_bio_put(req, bio);
out:
        nvmet_req_complete(req, status);
}

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

        switch (cmd->common.opcode) {
        case nvme_cmd_zone_append:
                req->execute = nvmet_bdev_execute_zone_append;
                return 0;
        case nvme_cmd_zone_mgmt_recv:
                req->execute = nvmet_bdev_execute_zone_mgmt_recv;
                return 0;
        case nvme_cmd_zone_mgmt_send:
                req->execute = nvmet_bdev_execute_zone_mgmt_send;
                return 0;
        default:
                return nvmet_bdev_parse_io_cmd(req);
        }
}