diff options
Diffstat (limited to 'drivers/scsi/scsi_bsg.c')
-rw-r--r-- | drivers/scsi/scsi_bsg.c | 106 |
1 files changed, 106 insertions, 0 deletions
diff --git a/drivers/scsi/scsi_bsg.c b/drivers/scsi/scsi_bsg.c new file mode 100644 index 000000000000..81c3853a2a80 --- /dev/null +++ b/drivers/scsi/scsi_bsg.c @@ -0,0 +1,106 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/bsg.h> +#include <scsi/scsi.h> +#include <scsi/scsi_ioctl.h> +#include <scsi/scsi_cmnd.h> +#include <scsi/scsi_device.h> +#include <scsi/sg.h> +#include "scsi_priv.h" + +#define uptr64(val) ((void __user *)(uintptr_t)(val)) + +static int scsi_bsg_sg_io_fn(struct request_queue *q, struct sg_io_v4 *hdr, + fmode_t mode, unsigned int timeout) +{ + struct scsi_request *sreq; + struct request *rq; + struct bio *bio; + int ret; + + if (hdr->protocol != BSG_PROTOCOL_SCSI || + hdr->subprotocol != BSG_SUB_PROTOCOL_SCSI_CMD) + return -EINVAL; + if (hdr->dout_xfer_len && hdr->din_xfer_len) { + pr_warn_once("BIDI support in bsg has been removed.\n"); + return -EOPNOTSUPP; + } + + rq = blk_get_request(q, hdr->dout_xfer_len ? + REQ_OP_DRV_OUT : REQ_OP_DRV_IN, 0); + if (IS_ERR(rq)) + return PTR_ERR(rq); + rq->timeout = timeout; + + ret = -ENOMEM; + sreq = scsi_req(rq); + sreq->cmd_len = hdr->request_len; + if (sreq->cmd_len > BLK_MAX_CDB) { + sreq->cmd = kzalloc(sreq->cmd_len, GFP_KERNEL); + if (!sreq->cmd) + goto out_put_request; + } + + ret = -EFAULT; + if (copy_from_user(sreq->cmd, uptr64(hdr->request), sreq->cmd_len)) + goto out_free_cmd; + ret = -EPERM; + if (!scsi_cmd_allowed(sreq->cmd, mode)) + goto out_free_cmd; + + ret = 0; + if (hdr->dout_xfer_len) { + ret = blk_rq_map_user(rq->q, rq, NULL, uptr64(hdr->dout_xferp), + hdr->dout_xfer_len, GFP_KERNEL); + } else if (hdr->din_xfer_len) { + ret = blk_rq_map_user(rq->q, rq, NULL, uptr64(hdr->din_xferp), + hdr->din_xfer_len, GFP_KERNEL); + } + + if (ret) + goto out_free_cmd; + + bio = rq->bio; + blk_execute_rq(NULL, rq, !(hdr->flags & BSG_FLAG_Q_AT_TAIL)); + + /* + * fill in all the output members + */ + hdr->device_status = sreq->result & 0xff; + hdr->transport_status = host_byte(sreq->result); + hdr->driver_status = 0; + if (scsi_status_is_check_condition(sreq->result)) + hdr->driver_status = DRIVER_SENSE; + hdr->info = 0; + if (hdr->device_status || hdr->transport_status || hdr->driver_status) + hdr->info |= SG_INFO_CHECK; + hdr->response_len = 0; + + if (sreq->sense_len && hdr->response) { + int len = min_t(unsigned int, hdr->max_response_len, + sreq->sense_len); + + if (copy_to_user(uptr64(hdr->response), sreq->sense, len)) + ret = -EFAULT; + else + hdr->response_len = len; + } + + if (rq_data_dir(rq) == READ) + hdr->din_resid = sreq->resid_len; + else + hdr->dout_resid = sreq->resid_len; + + blk_rq_unmap_user(bio); + +out_free_cmd: + scsi_req_free_cmd(scsi_req(rq)); +out_put_request: + blk_put_request(rq); + return ret; +} + +struct bsg_device *scsi_bsg_register_queue(struct scsi_device *sdev) +{ + return bsg_register_queue(sdev->request_queue, &sdev->sdev_gendev, + dev_name(&sdev->sdev_gendev), scsi_bsg_sg_io_fn); +} |