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285e71ea6f
Add hot cpu notifier to reset the request virtqueue affinity when doing cpu hotplug. Cc: linux-scsi@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Wanlong Gao <gaowanlong@cn.fujitsu.com> Reviewed-by: Asias He <asias@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
1046 lines
26 KiB
C
1046 lines
26 KiB
C
/*
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* Virtio SCSI HBA driver
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*
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* Copyright IBM Corp. 2010
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* Copyright Red Hat, Inc. 2011
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*
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* Authors:
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* Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
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* Paolo Bonzini <pbonzini@redhat.com>
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*
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* This work is licensed under the terms of the GNU GPL, version 2 or later.
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* See the COPYING file in the top-level directory.
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*
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/module.h>
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#include <linux/slab.h>
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#include <linux/mempool.h>
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#include <linux/virtio.h>
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#include <linux/virtio_ids.h>
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#include <linux/virtio_config.h>
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#include <linux/virtio_scsi.h>
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#include <linux/cpu.h>
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#include <scsi/scsi_host.h>
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#include <scsi/scsi_device.h>
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#include <scsi/scsi_cmnd.h>
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#define VIRTIO_SCSI_MEMPOOL_SZ 64
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#define VIRTIO_SCSI_EVENT_LEN 8
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#define VIRTIO_SCSI_VQ_BASE 2
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/* Command queue element */
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struct virtio_scsi_cmd {
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struct scsi_cmnd *sc;
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struct completion *comp;
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union {
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struct virtio_scsi_cmd_req cmd;
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struct virtio_scsi_ctrl_tmf_req tmf;
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struct virtio_scsi_ctrl_an_req an;
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} req;
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union {
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struct virtio_scsi_cmd_resp cmd;
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struct virtio_scsi_ctrl_tmf_resp tmf;
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struct virtio_scsi_ctrl_an_resp an;
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struct virtio_scsi_event evt;
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} resp;
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} ____cacheline_aligned_in_smp;
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struct virtio_scsi_event_node {
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struct virtio_scsi *vscsi;
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struct virtio_scsi_event event;
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struct work_struct work;
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};
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struct virtio_scsi_vq {
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/* Protects vq */
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spinlock_t vq_lock;
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struct virtqueue *vq;
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};
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/*
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* Per-target queue state.
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*
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* This struct holds the data needed by the queue steering policy. When a
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* target is sent multiple requests, we need to drive them to the same queue so
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* that FIFO processing order is kept. However, if a target was idle, we can
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* choose a queue arbitrarily. In this case the queue is chosen according to
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* the current VCPU, so the driver expects the number of request queues to be
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* equal to the number of VCPUs. This makes it easy and fast to select the
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* queue, and also lets the driver optimize the IRQ affinity for the virtqueues
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* (each virtqueue's affinity is set to the CPU that "owns" the queue).
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*
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* An interesting effect of this policy is that only writes to req_vq need to
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* take the tgt_lock. Read can be done outside the lock because:
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*
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* - writes of req_vq only occur when atomic_inc_return(&tgt->reqs) returns 1.
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* In that case, no other CPU is reading req_vq: even if they were in
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* virtscsi_queuecommand_multi, they would be spinning on tgt_lock.
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*
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* - reads of req_vq only occur when the target is not idle (reqs != 0).
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* A CPU that enters virtscsi_queuecommand_multi will not modify req_vq.
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*
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* Similarly, decrements of reqs are never concurrent with writes of req_vq.
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* Thus they can happen outside the tgt_lock, provided of course we make reqs
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* an atomic_t.
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*/
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struct virtio_scsi_target_state {
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/* This spinlock never held at the same time as vq_lock. */
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spinlock_t tgt_lock;
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/* Count of outstanding requests. */
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atomic_t reqs;
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/* Currently active virtqueue for requests sent to this target. */
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struct virtio_scsi_vq *req_vq;
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};
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/* Driver instance state */
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struct virtio_scsi {
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struct virtio_device *vdev;
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/* Get some buffers ready for event vq */
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struct virtio_scsi_event_node event_list[VIRTIO_SCSI_EVENT_LEN];
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u32 num_queues;
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/* If the affinity hint is set for virtqueues */
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bool affinity_hint_set;
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/* CPU hotplug notifier */
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struct notifier_block nb;
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struct virtio_scsi_vq ctrl_vq;
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struct virtio_scsi_vq event_vq;
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struct virtio_scsi_vq req_vqs[];
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};
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static struct kmem_cache *virtscsi_cmd_cache;
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static mempool_t *virtscsi_cmd_pool;
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static inline struct Scsi_Host *virtio_scsi_host(struct virtio_device *vdev)
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{
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return vdev->priv;
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}
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static void virtscsi_compute_resid(struct scsi_cmnd *sc, u32 resid)
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{
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if (!resid)
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return;
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if (!scsi_bidi_cmnd(sc)) {
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scsi_set_resid(sc, resid);
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return;
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}
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scsi_in(sc)->resid = min(resid, scsi_in(sc)->length);
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scsi_out(sc)->resid = resid - scsi_in(sc)->resid;
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}
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/**
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* virtscsi_complete_cmd - finish a scsi_cmd and invoke scsi_done
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*
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* Called with vq_lock held.
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*/
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static void virtscsi_complete_cmd(struct virtio_scsi *vscsi, void *buf)
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{
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struct virtio_scsi_cmd *cmd = buf;
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struct scsi_cmnd *sc = cmd->sc;
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struct virtio_scsi_cmd_resp *resp = &cmd->resp.cmd;
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struct virtio_scsi_target_state *tgt =
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scsi_target(sc->device)->hostdata;
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dev_dbg(&sc->device->sdev_gendev,
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"cmd %p response %u status %#02x sense_len %u\n",
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sc, resp->response, resp->status, resp->sense_len);
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sc->result = resp->status;
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virtscsi_compute_resid(sc, resp->resid);
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switch (resp->response) {
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case VIRTIO_SCSI_S_OK:
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set_host_byte(sc, DID_OK);
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break;
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case VIRTIO_SCSI_S_OVERRUN:
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set_host_byte(sc, DID_ERROR);
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break;
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case VIRTIO_SCSI_S_ABORTED:
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set_host_byte(sc, DID_ABORT);
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break;
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case VIRTIO_SCSI_S_BAD_TARGET:
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set_host_byte(sc, DID_BAD_TARGET);
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break;
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case VIRTIO_SCSI_S_RESET:
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set_host_byte(sc, DID_RESET);
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break;
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case VIRTIO_SCSI_S_BUSY:
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set_host_byte(sc, DID_BUS_BUSY);
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break;
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case VIRTIO_SCSI_S_TRANSPORT_FAILURE:
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set_host_byte(sc, DID_TRANSPORT_DISRUPTED);
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break;
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case VIRTIO_SCSI_S_TARGET_FAILURE:
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set_host_byte(sc, DID_TARGET_FAILURE);
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break;
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case VIRTIO_SCSI_S_NEXUS_FAILURE:
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set_host_byte(sc, DID_NEXUS_FAILURE);
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break;
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default:
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scmd_printk(KERN_WARNING, sc, "Unknown response %d",
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resp->response);
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/* fall through */
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case VIRTIO_SCSI_S_FAILURE:
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set_host_byte(sc, DID_ERROR);
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break;
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}
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WARN_ON(resp->sense_len > VIRTIO_SCSI_SENSE_SIZE);
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if (sc->sense_buffer) {
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memcpy(sc->sense_buffer, resp->sense,
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min_t(u32, resp->sense_len, VIRTIO_SCSI_SENSE_SIZE));
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if (resp->sense_len)
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set_driver_byte(sc, DRIVER_SENSE);
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}
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mempool_free(cmd, virtscsi_cmd_pool);
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sc->scsi_done(sc);
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atomic_dec(&tgt->reqs);
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}
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static void virtscsi_vq_done(struct virtio_scsi *vscsi,
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struct virtio_scsi_vq *virtscsi_vq,
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void (*fn)(struct virtio_scsi *vscsi, void *buf))
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{
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void *buf;
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unsigned int len;
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unsigned long flags;
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struct virtqueue *vq = virtscsi_vq->vq;
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spin_lock_irqsave(&virtscsi_vq->vq_lock, flags);
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do {
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virtqueue_disable_cb(vq);
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while ((buf = virtqueue_get_buf(vq, &len)) != NULL)
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fn(vscsi, buf);
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} while (!virtqueue_enable_cb(vq));
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spin_unlock_irqrestore(&virtscsi_vq->vq_lock, flags);
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}
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static void virtscsi_req_done(struct virtqueue *vq)
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{
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struct Scsi_Host *sh = virtio_scsi_host(vq->vdev);
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struct virtio_scsi *vscsi = shost_priv(sh);
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int index = vq->index - VIRTIO_SCSI_VQ_BASE;
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struct virtio_scsi_vq *req_vq = &vscsi->req_vqs[index];
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/*
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* Read req_vq before decrementing the reqs field in
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* virtscsi_complete_cmd.
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*
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* With barriers:
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*
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* CPU #0 virtscsi_queuecommand_multi (CPU #1)
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* ------------------------------------------------------------
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* lock vq_lock
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* read req_vq
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* read reqs (reqs = 1)
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* write reqs (reqs = 0)
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* increment reqs (reqs = 1)
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* write req_vq
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*
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* Possible reordering without barriers:
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*
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* CPU #0 virtscsi_queuecommand_multi (CPU #1)
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* ------------------------------------------------------------
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* lock vq_lock
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* read reqs (reqs = 1)
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* write reqs (reqs = 0)
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* increment reqs (reqs = 1)
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* write req_vq
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* read (wrong) req_vq
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*
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* We do not need a full smp_rmb, because req_vq is required to get
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* to tgt->reqs: tgt is &vscsi->tgt[sc->device->id], where sc is stored
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* in the virtqueue as the user token.
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*/
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smp_read_barrier_depends();
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virtscsi_vq_done(vscsi, req_vq, virtscsi_complete_cmd);
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};
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static void virtscsi_complete_free(struct virtio_scsi *vscsi, void *buf)
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{
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struct virtio_scsi_cmd *cmd = buf;
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if (cmd->comp)
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complete_all(cmd->comp);
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else
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mempool_free(cmd, virtscsi_cmd_pool);
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}
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static void virtscsi_ctrl_done(struct virtqueue *vq)
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{
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struct Scsi_Host *sh = virtio_scsi_host(vq->vdev);
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struct virtio_scsi *vscsi = shost_priv(sh);
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virtscsi_vq_done(vscsi, &vscsi->ctrl_vq, virtscsi_complete_free);
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};
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static int virtscsi_kick_event(struct virtio_scsi *vscsi,
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struct virtio_scsi_event_node *event_node)
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{
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int err;
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struct scatterlist sg;
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unsigned long flags;
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sg_init_one(&sg, &event_node->event, sizeof(struct virtio_scsi_event));
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spin_lock_irqsave(&vscsi->event_vq.vq_lock, flags);
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err = virtqueue_add_inbuf(vscsi->event_vq.vq, &sg, 1, event_node,
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GFP_ATOMIC);
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if (!err)
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virtqueue_kick(vscsi->event_vq.vq);
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spin_unlock_irqrestore(&vscsi->event_vq.vq_lock, flags);
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return err;
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}
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static int virtscsi_kick_event_all(struct virtio_scsi *vscsi)
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{
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int i;
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for (i = 0; i < VIRTIO_SCSI_EVENT_LEN; i++) {
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vscsi->event_list[i].vscsi = vscsi;
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virtscsi_kick_event(vscsi, &vscsi->event_list[i]);
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}
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return 0;
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}
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static void virtscsi_cancel_event_work(struct virtio_scsi *vscsi)
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{
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int i;
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for (i = 0; i < VIRTIO_SCSI_EVENT_LEN; i++)
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cancel_work_sync(&vscsi->event_list[i].work);
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}
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static void virtscsi_handle_transport_reset(struct virtio_scsi *vscsi,
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struct virtio_scsi_event *event)
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{
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struct scsi_device *sdev;
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struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev);
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unsigned int target = event->lun[1];
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unsigned int lun = (event->lun[2] << 8) | event->lun[3];
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switch (event->reason) {
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case VIRTIO_SCSI_EVT_RESET_RESCAN:
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scsi_add_device(shost, 0, target, lun);
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break;
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case VIRTIO_SCSI_EVT_RESET_REMOVED:
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sdev = scsi_device_lookup(shost, 0, target, lun);
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if (sdev) {
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scsi_remove_device(sdev);
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scsi_device_put(sdev);
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} else {
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pr_err("SCSI device %d 0 %d %d not found\n",
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shost->host_no, target, lun);
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}
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break;
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default:
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pr_info("Unsupport virtio scsi event reason %x\n", event->reason);
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}
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}
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static void virtscsi_handle_param_change(struct virtio_scsi *vscsi,
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struct virtio_scsi_event *event)
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{
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struct scsi_device *sdev;
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struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev);
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unsigned int target = event->lun[1];
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unsigned int lun = (event->lun[2] << 8) | event->lun[3];
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u8 asc = event->reason & 255;
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u8 ascq = event->reason >> 8;
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sdev = scsi_device_lookup(shost, 0, target, lun);
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if (!sdev) {
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pr_err("SCSI device %d 0 %d %d not found\n",
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shost->host_no, target, lun);
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return;
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}
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/* Handle "Parameters changed", "Mode parameters changed", and
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"Capacity data has changed". */
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if (asc == 0x2a && (ascq == 0x00 || ascq == 0x01 || ascq == 0x09))
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scsi_rescan_device(&sdev->sdev_gendev);
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scsi_device_put(sdev);
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}
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static void virtscsi_handle_event(struct work_struct *work)
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{
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struct virtio_scsi_event_node *event_node =
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container_of(work, struct virtio_scsi_event_node, work);
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struct virtio_scsi *vscsi = event_node->vscsi;
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struct virtio_scsi_event *event = &event_node->event;
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if (event->event & VIRTIO_SCSI_T_EVENTS_MISSED) {
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event->event &= ~VIRTIO_SCSI_T_EVENTS_MISSED;
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scsi_scan_host(virtio_scsi_host(vscsi->vdev));
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}
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switch (event->event) {
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case VIRTIO_SCSI_T_NO_EVENT:
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break;
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case VIRTIO_SCSI_T_TRANSPORT_RESET:
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virtscsi_handle_transport_reset(vscsi, event);
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break;
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case VIRTIO_SCSI_T_PARAM_CHANGE:
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virtscsi_handle_param_change(vscsi, event);
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break;
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default:
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pr_err("Unsupport virtio scsi event %x\n", event->event);
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}
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virtscsi_kick_event(vscsi, event_node);
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}
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static void virtscsi_complete_event(struct virtio_scsi *vscsi, void *buf)
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{
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struct virtio_scsi_event_node *event_node = buf;
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INIT_WORK(&event_node->work, virtscsi_handle_event);
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schedule_work(&event_node->work);
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}
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static void virtscsi_event_done(struct virtqueue *vq)
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{
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struct Scsi_Host *sh = virtio_scsi_host(vq->vdev);
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struct virtio_scsi *vscsi = shost_priv(sh);
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virtscsi_vq_done(vscsi, &vscsi->event_vq, virtscsi_complete_event);
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};
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/**
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* virtscsi_add_cmd - add a virtio_scsi_cmd to a virtqueue
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* @vq : the struct virtqueue we're talking about
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* @cmd : command structure
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* @req_size : size of the request buffer
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* @resp_size : size of the response buffer
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* @gfp : flags to use for memory allocations
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*/
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static int virtscsi_add_cmd(struct virtqueue *vq,
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struct virtio_scsi_cmd *cmd,
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size_t req_size, size_t resp_size, gfp_t gfp)
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{
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struct scsi_cmnd *sc = cmd->sc;
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struct scatterlist *sgs[4], req, resp;
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struct sg_table *out, *in;
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unsigned out_num = 0, in_num = 0;
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out = in = NULL;
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if (sc && sc->sc_data_direction != DMA_NONE) {
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if (sc->sc_data_direction != DMA_FROM_DEVICE)
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out = &scsi_out(sc)->table;
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if (sc->sc_data_direction != DMA_TO_DEVICE)
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in = &scsi_in(sc)->table;
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}
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/* Request header. */
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sg_init_one(&req, &cmd->req, req_size);
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sgs[out_num++] = &req;
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/* Data-out buffer. */
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if (out)
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sgs[out_num++] = out->sgl;
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/* Response header. */
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sg_init_one(&resp, &cmd->resp, resp_size);
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sgs[out_num + in_num++] = &resp;
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/* Data-in buffer */
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if (in)
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sgs[out_num + in_num++] = in->sgl;
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return virtqueue_add_sgs(vq, sgs, out_num, in_num, cmd, gfp);
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}
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|
|
static int virtscsi_kick_cmd(struct virtio_scsi_vq *vq,
|
|
struct virtio_scsi_cmd *cmd,
|
|
size_t req_size, size_t resp_size, gfp_t gfp)
|
|
{
|
|
unsigned long flags;
|
|
int err;
|
|
bool needs_kick = false;
|
|
|
|
spin_lock_irqsave(&vq->vq_lock, flags);
|
|
err = virtscsi_add_cmd(vq->vq, cmd, req_size, resp_size, gfp);
|
|
if (!err)
|
|
needs_kick = virtqueue_kick_prepare(vq->vq);
|
|
|
|
spin_unlock_irqrestore(&vq->vq_lock, flags);
|
|
|
|
if (needs_kick)
|
|
virtqueue_notify(vq->vq);
|
|
return err;
|
|
}
|
|
|
|
static int virtscsi_queuecommand(struct virtio_scsi *vscsi,
|
|
struct virtio_scsi_vq *req_vq,
|
|
struct scsi_cmnd *sc)
|
|
{
|
|
struct virtio_scsi_cmd *cmd;
|
|
int ret;
|
|
|
|
struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev);
|
|
BUG_ON(scsi_sg_count(sc) > shost->sg_tablesize);
|
|
|
|
/* TODO: check feature bit and fail if unsupported? */
|
|
BUG_ON(sc->sc_data_direction == DMA_BIDIRECTIONAL);
|
|
|
|
dev_dbg(&sc->device->sdev_gendev,
|
|
"cmd %p CDB: %#02x\n", sc, sc->cmnd[0]);
|
|
|
|
ret = SCSI_MLQUEUE_HOST_BUSY;
|
|
cmd = mempool_alloc(virtscsi_cmd_pool, GFP_ATOMIC);
|
|
if (!cmd)
|
|
goto out;
|
|
|
|
memset(cmd, 0, sizeof(*cmd));
|
|
cmd->sc = sc;
|
|
cmd->req.cmd = (struct virtio_scsi_cmd_req){
|
|
.lun[0] = 1,
|
|
.lun[1] = sc->device->id,
|
|
.lun[2] = (sc->device->lun >> 8) | 0x40,
|
|
.lun[3] = sc->device->lun & 0xff,
|
|
.tag = (unsigned long)sc,
|
|
.task_attr = VIRTIO_SCSI_S_SIMPLE,
|
|
.prio = 0,
|
|
.crn = 0,
|
|
};
|
|
|
|
BUG_ON(sc->cmd_len > VIRTIO_SCSI_CDB_SIZE);
|
|
memcpy(cmd->req.cmd.cdb, sc->cmnd, sc->cmd_len);
|
|
|
|
if (virtscsi_kick_cmd(req_vq, cmd,
|
|
sizeof cmd->req.cmd, sizeof cmd->resp.cmd,
|
|
GFP_ATOMIC) == 0)
|
|
ret = 0;
|
|
else
|
|
mempool_free(cmd, virtscsi_cmd_pool);
|
|
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
static int virtscsi_queuecommand_single(struct Scsi_Host *sh,
|
|
struct scsi_cmnd *sc)
|
|
{
|
|
struct virtio_scsi *vscsi = shost_priv(sh);
|
|
struct virtio_scsi_target_state *tgt =
|
|
scsi_target(sc->device)->hostdata;
|
|
|
|
atomic_inc(&tgt->reqs);
|
|
return virtscsi_queuecommand(vscsi, &vscsi->req_vqs[0], sc);
|
|
}
|
|
|
|
static struct virtio_scsi_vq *virtscsi_pick_vq(struct virtio_scsi *vscsi,
|
|
struct virtio_scsi_target_state *tgt)
|
|
{
|
|
struct virtio_scsi_vq *vq;
|
|
unsigned long flags;
|
|
u32 queue_num;
|
|
|
|
spin_lock_irqsave(&tgt->tgt_lock, flags);
|
|
|
|
/*
|
|
* The memory barrier after atomic_inc_return matches
|
|
* the smp_read_barrier_depends() in virtscsi_req_done.
|
|
*/
|
|
if (atomic_inc_return(&tgt->reqs) > 1)
|
|
vq = ACCESS_ONCE(tgt->req_vq);
|
|
else {
|
|
queue_num = smp_processor_id();
|
|
while (unlikely(queue_num >= vscsi->num_queues))
|
|
queue_num -= vscsi->num_queues;
|
|
|
|
tgt->req_vq = vq = &vscsi->req_vqs[queue_num];
|
|
}
|
|
|
|
spin_unlock_irqrestore(&tgt->tgt_lock, flags);
|
|
return vq;
|
|
}
|
|
|
|
static int virtscsi_queuecommand_multi(struct Scsi_Host *sh,
|
|
struct scsi_cmnd *sc)
|
|
{
|
|
struct virtio_scsi *vscsi = shost_priv(sh);
|
|
struct virtio_scsi_target_state *tgt =
|
|
scsi_target(sc->device)->hostdata;
|
|
struct virtio_scsi_vq *req_vq = virtscsi_pick_vq(vscsi, tgt);
|
|
|
|
return virtscsi_queuecommand(vscsi, req_vq, sc);
|
|
}
|
|
|
|
static int virtscsi_tmf(struct virtio_scsi *vscsi, struct virtio_scsi_cmd *cmd)
|
|
{
|
|
DECLARE_COMPLETION_ONSTACK(comp);
|
|
int ret = FAILED;
|
|
|
|
cmd->comp = ∁
|
|
if (virtscsi_kick_cmd(&vscsi->ctrl_vq, cmd,
|
|
sizeof cmd->req.tmf, sizeof cmd->resp.tmf,
|
|
GFP_NOIO) < 0)
|
|
goto out;
|
|
|
|
wait_for_completion(&comp);
|
|
if (cmd->resp.tmf.response == VIRTIO_SCSI_S_OK ||
|
|
cmd->resp.tmf.response == VIRTIO_SCSI_S_FUNCTION_SUCCEEDED)
|
|
ret = SUCCESS;
|
|
|
|
out:
|
|
mempool_free(cmd, virtscsi_cmd_pool);
|
|
return ret;
|
|
}
|
|
|
|
static int virtscsi_device_reset(struct scsi_cmnd *sc)
|
|
{
|
|
struct virtio_scsi *vscsi = shost_priv(sc->device->host);
|
|
struct virtio_scsi_cmd *cmd;
|
|
|
|
sdev_printk(KERN_INFO, sc->device, "device reset\n");
|
|
cmd = mempool_alloc(virtscsi_cmd_pool, GFP_NOIO);
|
|
if (!cmd)
|
|
return FAILED;
|
|
|
|
memset(cmd, 0, sizeof(*cmd));
|
|
cmd->sc = sc;
|
|
cmd->req.tmf = (struct virtio_scsi_ctrl_tmf_req){
|
|
.type = VIRTIO_SCSI_T_TMF,
|
|
.subtype = VIRTIO_SCSI_T_TMF_LOGICAL_UNIT_RESET,
|
|
.lun[0] = 1,
|
|
.lun[1] = sc->device->id,
|
|
.lun[2] = (sc->device->lun >> 8) | 0x40,
|
|
.lun[3] = sc->device->lun & 0xff,
|
|
};
|
|
return virtscsi_tmf(vscsi, cmd);
|
|
}
|
|
|
|
static int virtscsi_abort(struct scsi_cmnd *sc)
|
|
{
|
|
struct virtio_scsi *vscsi = shost_priv(sc->device->host);
|
|
struct virtio_scsi_cmd *cmd;
|
|
|
|
scmd_printk(KERN_INFO, sc, "abort\n");
|
|
cmd = mempool_alloc(virtscsi_cmd_pool, GFP_NOIO);
|
|
if (!cmd)
|
|
return FAILED;
|
|
|
|
memset(cmd, 0, sizeof(*cmd));
|
|
cmd->sc = sc;
|
|
cmd->req.tmf = (struct virtio_scsi_ctrl_tmf_req){
|
|
.type = VIRTIO_SCSI_T_TMF,
|
|
.subtype = VIRTIO_SCSI_T_TMF_ABORT_TASK,
|
|
.lun[0] = 1,
|
|
.lun[1] = sc->device->id,
|
|
.lun[2] = (sc->device->lun >> 8) | 0x40,
|
|
.lun[3] = sc->device->lun & 0xff,
|
|
.tag = (unsigned long)sc,
|
|
};
|
|
return virtscsi_tmf(vscsi, cmd);
|
|
}
|
|
|
|
static int virtscsi_target_alloc(struct scsi_target *starget)
|
|
{
|
|
struct virtio_scsi_target_state *tgt =
|
|
kmalloc(sizeof(*tgt), GFP_KERNEL);
|
|
if (!tgt)
|
|
return -ENOMEM;
|
|
|
|
spin_lock_init(&tgt->tgt_lock);
|
|
atomic_set(&tgt->reqs, 0);
|
|
tgt->req_vq = NULL;
|
|
|
|
starget->hostdata = tgt;
|
|
return 0;
|
|
}
|
|
|
|
static void virtscsi_target_destroy(struct scsi_target *starget)
|
|
{
|
|
struct virtio_scsi_target_state *tgt = starget->hostdata;
|
|
kfree(tgt);
|
|
}
|
|
|
|
static struct scsi_host_template virtscsi_host_template_single = {
|
|
.module = THIS_MODULE,
|
|
.name = "Virtio SCSI HBA",
|
|
.proc_name = "virtio_scsi",
|
|
.this_id = -1,
|
|
.queuecommand = virtscsi_queuecommand_single,
|
|
.eh_abort_handler = virtscsi_abort,
|
|
.eh_device_reset_handler = virtscsi_device_reset,
|
|
|
|
.can_queue = 1024,
|
|
.dma_boundary = UINT_MAX,
|
|
.use_clustering = ENABLE_CLUSTERING,
|
|
.target_alloc = virtscsi_target_alloc,
|
|
.target_destroy = virtscsi_target_destroy,
|
|
};
|
|
|
|
static struct scsi_host_template virtscsi_host_template_multi = {
|
|
.module = THIS_MODULE,
|
|
.name = "Virtio SCSI HBA",
|
|
.proc_name = "virtio_scsi",
|
|
.this_id = -1,
|
|
.queuecommand = virtscsi_queuecommand_multi,
|
|
.eh_abort_handler = virtscsi_abort,
|
|
.eh_device_reset_handler = virtscsi_device_reset,
|
|
|
|
.can_queue = 1024,
|
|
.dma_boundary = UINT_MAX,
|
|
.use_clustering = ENABLE_CLUSTERING,
|
|
.target_alloc = virtscsi_target_alloc,
|
|
.target_destroy = virtscsi_target_destroy,
|
|
};
|
|
|
|
#define virtscsi_config_get(vdev, fld) \
|
|
({ \
|
|
typeof(((struct virtio_scsi_config *)0)->fld) __val; \
|
|
vdev->config->get(vdev, \
|
|
offsetof(struct virtio_scsi_config, fld), \
|
|
&__val, sizeof(__val)); \
|
|
__val; \
|
|
})
|
|
|
|
#define virtscsi_config_set(vdev, fld, val) \
|
|
(void)({ \
|
|
typeof(((struct virtio_scsi_config *)0)->fld) __val = (val); \
|
|
vdev->config->set(vdev, \
|
|
offsetof(struct virtio_scsi_config, fld), \
|
|
&__val, sizeof(__val)); \
|
|
})
|
|
|
|
static void __virtscsi_set_affinity(struct virtio_scsi *vscsi, bool affinity)
|
|
{
|
|
int i;
|
|
int cpu;
|
|
|
|
/* In multiqueue mode, when the number of cpu is equal
|
|
* to the number of request queues, we let the qeueues
|
|
* to be private to one cpu by setting the affinity hint
|
|
* to eliminate the contention.
|
|
*/
|
|
if ((vscsi->num_queues == 1 ||
|
|
vscsi->num_queues != num_online_cpus()) && affinity) {
|
|
if (vscsi->affinity_hint_set)
|
|
affinity = false;
|
|
else
|
|
return;
|
|
}
|
|
|
|
if (affinity) {
|
|
i = 0;
|
|
for_each_online_cpu(cpu) {
|
|
virtqueue_set_affinity(vscsi->req_vqs[i].vq, cpu);
|
|
i++;
|
|
}
|
|
|
|
vscsi->affinity_hint_set = true;
|
|
} else {
|
|
for (i = 0; i < vscsi->num_queues - VIRTIO_SCSI_VQ_BASE; i++)
|
|
virtqueue_set_affinity(vscsi->req_vqs[i].vq, -1);
|
|
|
|
vscsi->affinity_hint_set = false;
|
|
}
|
|
}
|
|
|
|
static void virtscsi_set_affinity(struct virtio_scsi *vscsi, bool affinity)
|
|
{
|
|
get_online_cpus();
|
|
__virtscsi_set_affinity(vscsi, affinity);
|
|
put_online_cpus();
|
|
}
|
|
|
|
static int virtscsi_cpu_callback(struct notifier_block *nfb,
|
|
unsigned long action, void *hcpu)
|
|
{
|
|
struct virtio_scsi *vscsi = container_of(nfb, struct virtio_scsi, nb);
|
|
switch(action) {
|
|
case CPU_ONLINE:
|
|
case CPU_ONLINE_FROZEN:
|
|
case CPU_DEAD:
|
|
case CPU_DEAD_FROZEN:
|
|
__virtscsi_set_affinity(vscsi, true);
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
return NOTIFY_OK;
|
|
}
|
|
|
|
static void virtscsi_init_vq(struct virtio_scsi_vq *virtscsi_vq,
|
|
struct virtqueue *vq)
|
|
{
|
|
spin_lock_init(&virtscsi_vq->vq_lock);
|
|
virtscsi_vq->vq = vq;
|
|
}
|
|
|
|
static void virtscsi_scan(struct virtio_device *vdev)
|
|
{
|
|
struct Scsi_Host *shost = (struct Scsi_Host *)vdev->priv;
|
|
|
|
scsi_scan_host(shost);
|
|
}
|
|
|
|
static void virtscsi_remove_vqs(struct virtio_device *vdev)
|
|
{
|
|
struct Scsi_Host *sh = virtio_scsi_host(vdev);
|
|
struct virtio_scsi *vscsi = shost_priv(sh);
|
|
|
|
virtscsi_set_affinity(vscsi, false);
|
|
|
|
/* Stop all the virtqueues. */
|
|
vdev->config->reset(vdev);
|
|
|
|
vdev->config->del_vqs(vdev);
|
|
}
|
|
|
|
static int virtscsi_init(struct virtio_device *vdev,
|
|
struct virtio_scsi *vscsi)
|
|
{
|
|
int err;
|
|
u32 i;
|
|
u32 num_vqs;
|
|
vq_callback_t **callbacks;
|
|
const char **names;
|
|
struct virtqueue **vqs;
|
|
|
|
num_vqs = vscsi->num_queues + VIRTIO_SCSI_VQ_BASE;
|
|
vqs = kmalloc(num_vqs * sizeof(struct virtqueue *), GFP_KERNEL);
|
|
callbacks = kmalloc(num_vqs * sizeof(vq_callback_t *), GFP_KERNEL);
|
|
names = kmalloc(num_vqs * sizeof(char *), GFP_KERNEL);
|
|
|
|
if (!callbacks || !vqs || !names) {
|
|
err = -ENOMEM;
|
|
goto out;
|
|
}
|
|
|
|
callbacks[0] = virtscsi_ctrl_done;
|
|
callbacks[1] = virtscsi_event_done;
|
|
names[0] = "control";
|
|
names[1] = "event";
|
|
for (i = VIRTIO_SCSI_VQ_BASE; i < num_vqs; i++) {
|
|
callbacks[i] = virtscsi_req_done;
|
|
names[i] = "request";
|
|
}
|
|
|
|
/* Discover virtqueues and write information to configuration. */
|
|
err = vdev->config->find_vqs(vdev, num_vqs, vqs, callbacks, names);
|
|
if (err)
|
|
goto out;
|
|
|
|
virtscsi_init_vq(&vscsi->ctrl_vq, vqs[0]);
|
|
virtscsi_init_vq(&vscsi->event_vq, vqs[1]);
|
|
for (i = VIRTIO_SCSI_VQ_BASE; i < num_vqs; i++)
|
|
virtscsi_init_vq(&vscsi->req_vqs[i - VIRTIO_SCSI_VQ_BASE],
|
|
vqs[i]);
|
|
|
|
virtscsi_set_affinity(vscsi, true);
|
|
|
|
virtscsi_config_set(vdev, cdb_size, VIRTIO_SCSI_CDB_SIZE);
|
|
virtscsi_config_set(vdev, sense_size, VIRTIO_SCSI_SENSE_SIZE);
|
|
|
|
if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG))
|
|
virtscsi_kick_event_all(vscsi);
|
|
|
|
err = 0;
|
|
|
|
out:
|
|
kfree(names);
|
|
kfree(callbacks);
|
|
kfree(vqs);
|
|
if (err)
|
|
virtscsi_remove_vqs(vdev);
|
|
return err;
|
|
}
|
|
|
|
static int virtscsi_probe(struct virtio_device *vdev)
|
|
{
|
|
struct Scsi_Host *shost;
|
|
struct virtio_scsi *vscsi;
|
|
int err;
|
|
u32 sg_elems, num_targets;
|
|
u32 cmd_per_lun;
|
|
u32 num_queues;
|
|
struct scsi_host_template *hostt;
|
|
|
|
/* We need to know how many queues before we allocate. */
|
|
num_queues = virtscsi_config_get(vdev, num_queues) ? : 1;
|
|
|
|
num_targets = virtscsi_config_get(vdev, max_target) + 1;
|
|
|
|
if (num_queues == 1)
|
|
hostt = &virtscsi_host_template_single;
|
|
else
|
|
hostt = &virtscsi_host_template_multi;
|
|
|
|
shost = scsi_host_alloc(hostt,
|
|
sizeof(*vscsi) + sizeof(vscsi->req_vqs[0]) * num_queues);
|
|
if (!shost)
|
|
return -ENOMEM;
|
|
|
|
sg_elems = virtscsi_config_get(vdev, seg_max) ?: 1;
|
|
shost->sg_tablesize = sg_elems;
|
|
vscsi = shost_priv(shost);
|
|
vscsi->vdev = vdev;
|
|
vscsi->num_queues = num_queues;
|
|
vdev->priv = shost;
|
|
|
|
err = virtscsi_init(vdev, vscsi);
|
|
if (err)
|
|
goto virtscsi_init_failed;
|
|
|
|
vscsi->nb.notifier_call = &virtscsi_cpu_callback;
|
|
err = register_hotcpu_notifier(&vscsi->nb);
|
|
if (err) {
|
|
pr_err("registering cpu notifier failed\n");
|
|
goto scsi_add_host_failed;
|
|
}
|
|
|
|
cmd_per_lun = virtscsi_config_get(vdev, cmd_per_lun) ?: 1;
|
|
shost->cmd_per_lun = min_t(u32, cmd_per_lun, shost->can_queue);
|
|
shost->max_sectors = virtscsi_config_get(vdev, max_sectors) ?: 0xFFFF;
|
|
|
|
/* LUNs > 256 are reported with format 1, so they go in the range
|
|
* 16640-32767.
|
|
*/
|
|
shost->max_lun = virtscsi_config_get(vdev, max_lun) + 1 + 0x4000;
|
|
shost->max_id = num_targets;
|
|
shost->max_channel = 0;
|
|
shost->max_cmd_len = VIRTIO_SCSI_CDB_SIZE;
|
|
err = scsi_add_host(shost, &vdev->dev);
|
|
if (err)
|
|
goto scsi_add_host_failed;
|
|
/*
|
|
* scsi_scan_host() happens in virtscsi_scan() via virtio_driver->scan()
|
|
* after VIRTIO_CONFIG_S_DRIVER_OK has been set..
|
|
*/
|
|
return 0;
|
|
|
|
scsi_add_host_failed:
|
|
vdev->config->del_vqs(vdev);
|
|
virtscsi_init_failed:
|
|
scsi_host_put(shost);
|
|
return err;
|
|
}
|
|
|
|
static void virtscsi_remove(struct virtio_device *vdev)
|
|
{
|
|
struct Scsi_Host *shost = virtio_scsi_host(vdev);
|
|
struct virtio_scsi *vscsi = shost_priv(shost);
|
|
|
|
if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG))
|
|
virtscsi_cancel_event_work(vscsi);
|
|
|
|
scsi_remove_host(shost);
|
|
|
|
unregister_hotcpu_notifier(&vscsi->nb);
|
|
|
|
virtscsi_remove_vqs(vdev);
|
|
scsi_host_put(shost);
|
|
}
|
|
|
|
#ifdef CONFIG_PM
|
|
static int virtscsi_freeze(struct virtio_device *vdev)
|
|
{
|
|
virtscsi_remove_vqs(vdev);
|
|
return 0;
|
|
}
|
|
|
|
static int virtscsi_restore(struct virtio_device *vdev)
|
|
{
|
|
struct Scsi_Host *sh = virtio_scsi_host(vdev);
|
|
struct virtio_scsi *vscsi = shost_priv(sh);
|
|
|
|
return virtscsi_init(vdev, vscsi);
|
|
}
|
|
#endif
|
|
|
|
static struct virtio_device_id id_table[] = {
|
|
{ VIRTIO_ID_SCSI, VIRTIO_DEV_ANY_ID },
|
|
{ 0 },
|
|
};
|
|
|
|
static unsigned int features[] = {
|
|
VIRTIO_SCSI_F_HOTPLUG,
|
|
VIRTIO_SCSI_F_CHANGE,
|
|
};
|
|
|
|
static struct virtio_driver virtio_scsi_driver = {
|
|
.feature_table = features,
|
|
.feature_table_size = ARRAY_SIZE(features),
|
|
.driver.name = KBUILD_MODNAME,
|
|
.driver.owner = THIS_MODULE,
|
|
.id_table = id_table,
|
|
.probe = virtscsi_probe,
|
|
.scan = virtscsi_scan,
|
|
#ifdef CONFIG_PM
|
|
.freeze = virtscsi_freeze,
|
|
.restore = virtscsi_restore,
|
|
#endif
|
|
.remove = virtscsi_remove,
|
|
};
|
|
|
|
static int __init init(void)
|
|
{
|
|
int ret = -ENOMEM;
|
|
|
|
virtscsi_cmd_cache = KMEM_CACHE(virtio_scsi_cmd, 0);
|
|
if (!virtscsi_cmd_cache) {
|
|
pr_err("kmem_cache_create() for virtscsi_cmd_cache failed\n");
|
|
goto error;
|
|
}
|
|
|
|
|
|
virtscsi_cmd_pool =
|
|
mempool_create_slab_pool(VIRTIO_SCSI_MEMPOOL_SZ,
|
|
virtscsi_cmd_cache);
|
|
if (!virtscsi_cmd_pool) {
|
|
pr_err("mempool_create() for virtscsi_cmd_pool failed\n");
|
|
goto error;
|
|
}
|
|
ret = register_virtio_driver(&virtio_scsi_driver);
|
|
if (ret < 0)
|
|
goto error;
|
|
|
|
return 0;
|
|
|
|
error:
|
|
if (virtscsi_cmd_pool) {
|
|
mempool_destroy(virtscsi_cmd_pool);
|
|
virtscsi_cmd_pool = NULL;
|
|
}
|
|
if (virtscsi_cmd_cache) {
|
|
kmem_cache_destroy(virtscsi_cmd_cache);
|
|
virtscsi_cmd_cache = NULL;
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
static void __exit fini(void)
|
|
{
|
|
unregister_virtio_driver(&virtio_scsi_driver);
|
|
mempool_destroy(virtscsi_cmd_pool);
|
|
kmem_cache_destroy(virtscsi_cmd_cache);
|
|
}
|
|
module_init(init);
|
|
module_exit(fini);
|
|
|
|
MODULE_DEVICE_TABLE(virtio, id_table);
|
|
MODULE_DESCRIPTION("Virtio SCSI HBA driver");
|
|
MODULE_LICENSE("GPL");
|