linux-imx

// SPDX-License-Identifier: GPL-2.0

/*

 * Common code for the NVMe target.

 * Copyright (c) 2015-2016 HGST, a Western Digital Company.

 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/module.h>

#include <linux/random.h>

#include <linux/rculist.h>

#include <linux/pci-p2pdma.h>

​

#include "nvmet.h"

​

struct workqueue_struct *buffered_io_wq;

static const struct nvmet_fabrics_ops *nvmet_transports[NVMF_TRTYPE_MAX];

static DEFINE_IDA(cntlid_ida);

​

/*

 * This read/write semaphore is used to synchronize access to configuration

 * information on a target system that will result in discovery log page

 * information change for at least one host.

 * The full list of resources to protected by this semaphore is:

 *

 *  - subsystems list

 *  - per-subsystem allowed hosts list

 *  - allow_any_host subsystem attribute

 *  - nvmet_genctr

 *  - the nvmet_transports array

 *

 * When updating any of those lists/structures write lock should be obtained,

 * while when reading (popolating discovery log page or checking host-subsystem

 * link) read lock is obtained to allow concurrent reads.

 */

DECLARE_RWSEM(nvmet_config_sem);

​

u32 nvmet_ana_group_enabled[NVMET_MAX_ANAGRPS + 1];

u64 nvmet_ana_chgcnt;

DECLARE_RWSEM(nvmet_ana_sem);

​

inline u16 errno_to_nvme_status(struct nvmet_req *req, int errno)

{

    u16 status;

​

    switch (errno) {

    case -ENOSPC:

        req->error_loc = offsetof(struct nvme_rw_command, length);

        status = NVME_SC_CAP_EXCEEDED | NVME_SC_DNR;

        break;

    case -EREMOTEIO:

        req->error_loc = offsetof(struct nvme_rw_command, slba);

        status = NVME_SC_LBA_RANGE | NVME_SC_DNR;

        break;

    case -EOPNOTSUPP:

        req->error_loc = offsetof(struct nvme_common_command, opcode);

        switch (req->cmd->common.opcode) {

        case nvme_cmd_dsm:

        case nvme_cmd_write_zeroes:

            status = NVME_SC_ONCS_NOT_SUPPORTED | NVME_SC_DNR;

            break;

        default:

            status = NVME_SC_INVALID_OPCODE | NVME_SC_DNR;

        }

        break;

    case -ENODATA:

        req->error_loc = offsetof(struct nvme_rw_command, nsid);

        status = NVME_SC_ACCESS_DENIED;

        break;

    case -EIO:

        /* FALLTHRU */

    default:

        req->error_loc = offsetof(struct nvme_common_command, opcode);

        status = NVME_SC_INTERNAL | NVME_SC_DNR;

    }

​

    return status;

}

​

static struct nvmet_subsys *nvmet_find_get_subsys(struct nvmet_port *port,

        const char *subsysnqn);

​

u16 nvmet_copy_to_sgl(struct nvmet_req *req, off_t off, const void *buf,

        size_t len)

{

    if (sg_pcopy_from_buffer(req->sg, req->sg_cnt, buf, len, off) != len) {

        req->error_loc = offsetof(struct nvme_common_command, dptr);

        return NVME_SC_SGL_INVALID_DATA | NVME_SC_DNR;

    }

    return 0;

}

​

u16 nvmet_copy_from_sgl(struct nvmet_req *req, off_t off, void *buf, size_t len)

{