On Jun 18 07:53, Keith Busch wrote:
> diff --git a/drivers/nvme/host/zns.c b/drivers/nvme/host/zns.c
> new file mode 100644
> index 000000000000..d57fbbfe15e8
> --- /dev/null
> +++ b/drivers/nvme/host/zns.c
> @@ -0,0 +1,238 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2020 Western Digital Corporation or its affiliates.
> + */
> +
> +#include <linux/blkdev.h>
> +#include <linux/vmalloc.h>
> +#include "nvme.h"
> +
> +static int nvme_set_max_append(struct nvme_ctrl *ctrl)
> +{
> + struct nvme_command c = { };
> + struct nvme_id_ctrl_zns *id;
> + int status;
> +
> + id = kzalloc(sizeof(*id), GFP_KERNEL);
> + if (!id)
> + return -ENOMEM;
> +
> + c.identify.opcode = nvme_admin_identify;
> + c.identify.cns = NVME_ID_CNS_CS_CTRL;
> + c.identify.csi = NVME_CSI_ZNS;
> +
> + status = nvme_submit_sync_cmd(ctrl->admin_q, &c, id, sizeof(*id));
> + if (status) {
> + kfree(id);
> + return status;
> + }
> +
> + ctrl->max_zone_append = 1 << (id->zamds + 3);
> + kfree(id);
> + return 0;
> +}
> +
> +int nvme_update_zone_info(struct gendisk *disk, struct nvme_ns *ns,
> + unsigned lbaf)
> +{
> + struct nvme_effects_log *log = ns->head->effects;
> + struct request_queue *q = disk->queue;
> + struct nvme_command c = { };
> + struct nvme_id_ns_zns *id;
> + int status;
> +
> + /* Driver requires zone append support */
> + if (!(log->iocs[nvme_cmd_zone_append] & NVME_CMD_EFFECTS_CSUPP))
> + return -ENODEV;
> +
> + /* Lazily query controller append limit for the first zoned namespace */
> + if (!ns->ctrl->max_zone_append) {
> + status = nvme_set_max_append(ns->ctrl);
> + if (status)
> + return status;
> + }
> +
> + id = kzalloc(sizeof(*id), GFP_KERNEL);
> + if (!id)
> + return -ENOMEM;
> +
> + c.identify.opcode = nvme_admin_identify;
> + c.identify.nsid = cpu_to_le32(ns->head->ns_id);
> + c.identify.cns = NVME_ID_CNS_CS_NS;
> + c.identify.csi = NVME_CSI_ZNS;
> +
> + status = nvme_submit_sync_cmd(ns->ctrl->admin_q, &c, id, sizeof(*id));
> + if (status)
> + goto free_data;
> +
> + /*
> + * We currently do not handle devices requiring any of the zoned
> + * operation characteristics.
> + */
> + if (id->zoc) {
> + status = -EINVAL;
> + goto free_data;
> + }
A dev_err() here would be nice. I had to dig a bit to track down why my
emulated device didn't show up ;)
