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Diffstat (limited to 'drivers/scsi/virtio_scsi.c')
-rw-r--r--drivers/scsi/virtio_scsi.c337
1 files changed, 272 insertions, 65 deletions
diff --git a/drivers/scsi/virtio_scsi.c b/drivers/scsi/virtio_scsi.c
index 1b384311726..c7030fbee79 100644
--- a/drivers/scsi/virtio_scsi.c
+++ b/drivers/scsi/virtio_scsi.c
@@ -25,6 +25,7 @@
#include <scsi/scsi_cmnd.h>
#define VIRTIO_SCSI_MEMPOOL_SZ 64
+#define VIRTIO_SCSI_EVENT_LEN 8
/* Command queue element */
struct virtio_scsi_cmd {
@@ -43,20 +44,42 @@ struct virtio_scsi_cmd {
} resp;
} ____cacheline_aligned_in_smp;
-/* Driver instance state */
-struct virtio_scsi {
- /* Protects ctrl_vq, req_vq and sg[] */
+struct virtio_scsi_event_node {
+ struct virtio_scsi *vscsi;
+ struct virtio_scsi_event event;
+ struct work_struct work;
+};
+
+struct virtio_scsi_vq {
+ /* Protects vq */
spinlock_t vq_lock;
- struct virtio_device *vdev;
- struct virtqueue *ctrl_vq;
- struct virtqueue *event_vq;
- struct virtqueue *req_vq;
+ struct virtqueue *vq;
+};
+
+/* Per-target queue state */
+struct virtio_scsi_target_state {
+ /* Protects sg. Lock hierarchy is tgt_lock -> vq_lock. */
+ spinlock_t tgt_lock;
/* For sglist construction when adding commands to the virtqueue. */
struct scatterlist sg[];
};
+/* Driver instance state */
+struct virtio_scsi {
+ struct virtio_device *vdev;
+
+ struct virtio_scsi_vq ctrl_vq;
+ struct virtio_scsi_vq event_vq;
+ struct virtio_scsi_vq req_vq;
+
+ /* Get some buffers ready for event vq */
+ struct virtio_scsi_event_node event_list[VIRTIO_SCSI_EVENT_LEN];
+
+ struct virtio_scsi_target_state *tgt[];
+};
+
static struct kmem_cache *virtscsi_cmd_cache;
static mempool_t *virtscsi_cmd_pool;
@@ -147,26 +170,25 @@ static void virtscsi_complete_cmd(void *buf)
static void virtscsi_vq_done(struct virtqueue *vq, void (*fn)(void *buf))
{
- struct Scsi_Host *sh = virtio_scsi_host(vq->vdev);
- struct virtio_scsi *vscsi = shost_priv(sh);
void *buf;
- unsigned long flags;
unsigned int len;
- spin_lock_irqsave(&vscsi->vq_lock, flags);
-
do {
virtqueue_disable_cb(vq);
while ((buf = virtqueue_get_buf(vq, &len)) != NULL)
fn(buf);
} while (!virtqueue_enable_cb(vq));
-
- spin_unlock_irqrestore(&vscsi->vq_lock, flags);
}
static void virtscsi_req_done(struct virtqueue *vq)
{
+ struct Scsi_Host *sh = virtio_scsi_host(vq->vdev);
+ struct virtio_scsi *vscsi = shost_priv(sh);
+ unsigned long flags;
+
+ spin_lock_irqsave(&vscsi->req_vq.vq_lock, flags);
virtscsi_vq_done(vq, virtscsi_complete_cmd);
+ spin_unlock_irqrestore(&vscsi->req_vq.vq_lock, flags);
};
static void virtscsi_complete_free(void *buf)
@@ -181,12 +203,123 @@ static void virtscsi_complete_free(void *buf)
static void virtscsi_ctrl_done(struct virtqueue *vq)
{
+ struct Scsi_Host *sh = virtio_scsi_host(vq->vdev);
+ struct virtio_scsi *vscsi = shost_priv(sh);
+ unsigned long flags;
+
+ spin_lock_irqsave(&vscsi->ctrl_vq.vq_lock, flags);
virtscsi_vq_done(vq, virtscsi_complete_free);
+ spin_unlock_irqrestore(&vscsi->ctrl_vq.vq_lock, flags);
};
+static int virtscsi_kick_event(struct virtio_scsi *vscsi,
+ struct virtio_scsi_event_node *event_node)
+{
+ int ret;
+ struct scatterlist sg;
+ unsigned long flags;
+
+ sg_set_buf(&sg, &event_node->event, sizeof(struct virtio_scsi_event));
+
+ spin_lock_irqsave(&vscsi->event_vq.vq_lock, flags);
+
+ ret = virtqueue_add_buf(vscsi->event_vq.vq, &sg, 0, 1, event_node, GFP_ATOMIC);
+ if (ret >= 0)
+ virtqueue_kick(vscsi->event_vq.vq);
+
+ spin_unlock_irqrestore(&vscsi->event_vq.vq_lock, flags);
+
+ return ret;
+}
+
+static int virtscsi_kick_event_all(struct virtio_scsi *vscsi)
+{
+ int i;
+
+ for (i = 0; i < VIRTIO_SCSI_EVENT_LEN; i++) {
+ vscsi->event_list[i].vscsi = vscsi;
+ virtscsi_kick_event(vscsi, &vscsi->event_list[i]);
+ }
+
+ return 0;
+}
+
+static void virtscsi_cancel_event_work(struct virtio_scsi *vscsi)
+{
+ int i;
+
+ for (i = 0; i < VIRTIO_SCSI_EVENT_LEN; i++)
+ cancel_work_sync(&vscsi->event_list[i].work);
+}
+
+static void virtscsi_handle_transport_reset(struct virtio_scsi *vscsi,
+ struct virtio_scsi_event *event)
+{
+ struct scsi_device *sdev;
+ struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev);
+ unsigned int target = event->lun[1];
+ unsigned int lun = (event->lun[2] << 8) | event->lun[3];
+
+ switch (event->reason) {
+ case VIRTIO_SCSI_EVT_RESET_RESCAN:
+ scsi_add_device(shost, 0, target, lun);
+ break;
+ case VIRTIO_SCSI_EVT_RESET_REMOVED:
+ sdev = scsi_device_lookup(shost, 0, target, lun);
+ if (sdev) {
+ scsi_remove_device(sdev);
+ scsi_device_put(sdev);
+ } else {
+ pr_err("SCSI device %d 0 %d %d not found\n",
+ shost->host_no, target, lun);
+ }
+ break;
+ default:
+ pr_info("Unsupport virtio scsi event reason %x\n", event->reason);
+ }
+}
+
+static void virtscsi_handle_event(struct work_struct *work)
+{
+ struct virtio_scsi_event_node *event_node =
+ container_of(work, struct virtio_scsi_event_node, work);
+ struct virtio_scsi *vscsi = event_node->vscsi;
+ struct virtio_scsi_event *event = &event_node->event;
+
+ if (event->event & VIRTIO_SCSI_T_EVENTS_MISSED) {
+ event->event &= ~VIRTIO_SCSI_T_EVENTS_MISSED;
+ scsi_scan_host(virtio_scsi_host(vscsi->vdev));
+ }
+
+ switch (event->event) {
+ case VIRTIO_SCSI_T_NO_EVENT:
+ break;
+ case VIRTIO_SCSI_T_TRANSPORT_RESET:
+ virtscsi_handle_transport_reset(vscsi, event);
+ break;
+ default:
+ pr_err("Unsupport virtio scsi event %x\n", event->event);
+ }
+ virtscsi_kick_event(vscsi, event_node);
+}
+
+static void virtscsi_complete_event(void *buf)
+{
+ struct virtio_scsi_event_node *event_node = buf;
+
+ INIT_WORK(&event_node->work, virtscsi_handle_event);
+ schedule_work(&event_node->work);
+}
+
static void virtscsi_event_done(struct virtqueue *vq)
{
- virtscsi_vq_done(vq, virtscsi_complete_free);
+ struct Scsi_Host *sh = virtio_scsi_host(vq->vdev);
+ struct virtio_scsi *vscsi = shost_priv(sh);
+ unsigned long flags;
+
+ spin_lock_irqsave(&vscsi->event_vq.vq_lock, flags);
+ virtscsi_vq_done(vq, virtscsi_complete_event);
+ spin_unlock_irqrestore(&vscsi->event_vq.vq_lock, flags);
};
static void virtscsi_map_sgl(struct scatterlist *sg, unsigned int *p_idx,
@@ -212,25 +345,17 @@ static void virtscsi_map_sgl(struct scatterlist *sg, unsigned int *p_idx,
* @req_size : size of the request buffer
* @resp_size : size of the response buffer
*
- * Called with vq_lock held.
+ * Called with tgt_lock held.
*/
-static void virtscsi_map_cmd(struct virtio_scsi *vscsi,
+static void virtscsi_map_cmd(struct virtio_scsi_target_state *tgt,
struct virtio_scsi_cmd *cmd,
unsigned *out_num, unsigned *in_num,
size_t req_size, size_t resp_size)
{
struct scsi_cmnd *sc = cmd->sc;
- struct scatterlist *sg = vscsi->sg;
+ struct scatterlist *sg = tgt->sg;
unsigned int idx = 0;
- if (sc) {
- 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);
- }
-
/* Request header. */
sg_set_buf(&sg[idx++], &cmd->req, req_size);
@@ -250,7 +375,8 @@ static void virtscsi_map_cmd(struct virtio_scsi *vscsi,
*in_num = idx - *out_num;
}
-static int virtscsi_kick_cmd(struct virtio_scsi *vscsi, struct virtqueue *vq,
+static int virtscsi_kick_cmd(struct virtio_scsi_target_state *tgt,
+ struct virtio_scsi_vq *vq,
struct virtio_scsi_cmd *cmd,
size_t req_size, size_t resp_size, gfp_t gfp)
{
@@ -258,24 +384,35 @@ static int virtscsi_kick_cmd(struct virtio_scsi *vscsi, struct virtqueue *vq,
unsigned long flags;
int ret;
- spin_lock_irqsave(&vscsi->vq_lock, flags);
-
- virtscsi_map_cmd(vscsi, cmd, &out_num, &in_num, req_size, resp_size);
+ spin_lock_irqsave(&tgt->tgt_lock, flags);
+ virtscsi_map_cmd(tgt, cmd, &out_num, &in_num, req_size, resp_size);
- ret = virtqueue_add_buf(vq, vscsi->sg, out_num, in_num, cmd, gfp);
+ spin_lock(&vq->vq_lock);
+ ret = virtqueue_add_buf(vq->vq, tgt->sg, out_num, in_num, cmd, gfp);
+ spin_unlock(&tgt->tgt_lock);
if (ret >= 0)
- virtqueue_kick(vq);
+ ret = virtqueue_kick_prepare(vq->vq);
+
+ spin_unlock_irqrestore(&vq->vq_lock, flags);
- spin_unlock_irqrestore(&vscsi->vq_lock, flags);
+ if (ret > 0)
+ virtqueue_notify(vq->vq);
return ret;
}
static int virtscsi_queuecommand(struct Scsi_Host *sh, struct scsi_cmnd *sc)
{
struct virtio_scsi *vscsi = shost_priv(sh);
+ struct virtio_scsi_target_state *tgt = vscsi->tgt[sc->device->id];
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]);
@@ -300,7 +437,7 @@ static int virtscsi_queuecommand(struct Scsi_Host *sh, struct scsi_cmnd *sc)
BUG_ON(sc->cmd_len > VIRTIO_SCSI_CDB_SIZE);
memcpy(cmd->req.cmd.cdb, sc->cmnd, sc->cmd_len);
- if (virtscsi_kick_cmd(vscsi, vscsi->req_vq, cmd,
+ if (virtscsi_kick_cmd(tgt, &vscsi->req_vq, cmd,
sizeof cmd->req.cmd, sizeof cmd->resp.cmd,
GFP_ATOMIC) >= 0)
ret = 0;
@@ -312,10 +449,11 @@ out:
static int virtscsi_tmf(struct virtio_scsi *vscsi, struct virtio_scsi_cmd *cmd)
{
DECLARE_COMPLETION_ONSTACK(comp);
+ struct virtio_scsi_target_state *tgt = vscsi->tgt[cmd->sc->device->id];
int ret = FAILED;
cmd->comp = &comp;
- if (virtscsi_kick_cmd(vscsi, vscsi->ctrl_vq, cmd,
+ if (virtscsi_kick_cmd(tgt, &vscsi->ctrl_vq, cmd,
sizeof cmd->req.tmf, sizeof cmd->resp.tmf,
GFP_NOIO) < 0)
goto out;
@@ -408,11 +546,63 @@ static struct scsi_host_template virtscsi_host_template = {
&__val, sizeof(__val)); \
})
+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 struct virtio_scsi_target_state *virtscsi_alloc_tgt(
+ struct virtio_device *vdev, int sg_elems)
+{
+ struct virtio_scsi_target_state *tgt;
+ gfp_t gfp_mask = GFP_KERNEL;
+
+ /* We need extra sg elements at head and tail. */
+ tgt = kmalloc(sizeof(*tgt) + sizeof(tgt->sg[0]) * (sg_elems + 2),
+ gfp_mask);
+
+ if (!tgt)
+ return NULL;
+
+ spin_lock_init(&tgt->tgt_lock);
+ sg_init_table(tgt->sg, sg_elems + 2);
+ return tgt;
+}
+
+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);
+ u32 i, num_targets;
+
+ /* Stop all the virtqueues. */
+ vdev->config->reset(vdev);
+
+ num_targets = sh->max_id;
+ for (i = 0; i < num_targets; i++) {
+ kfree(vscsi->tgt[i]);
+ vscsi->tgt[i] = NULL;
+ }
+
+ vdev->config->del_vqs(vdev);
+}
+
static int virtscsi_init(struct virtio_device *vdev,
- struct virtio_scsi *vscsi)
+ struct virtio_scsi *vscsi, int num_targets)
{
int err;
struct virtqueue *vqs[3];
+ u32 i, sg_elems;
+
vq_callback_t *callbacks[] = {
virtscsi_ctrl_done,
virtscsi_event_done,
@@ -429,13 +619,32 @@ static int virtscsi_init(struct virtio_device *vdev,
if (err)
return err;
- vscsi->ctrl_vq = vqs[0];
- vscsi->event_vq = vqs[1];
- vscsi->req_vq = vqs[2];
+ virtscsi_init_vq(&vscsi->ctrl_vq, vqs[0]);
+ virtscsi_init_vq(&vscsi->event_vq, vqs[1]);
+ virtscsi_init_vq(&vscsi->req_vq, vqs[2]);
virtscsi_config_set(vdev, cdb_size, VIRTIO_SCSI_CDB_SIZE);
virtscsi_config_set(vdev, sense_size, VIRTIO_SCSI_SENSE_SIZE);
- return 0;
+
+ if (virtio_has_feature(vdev, VIRTIO_SCSI_F_HOTPLUG))
+ virtscsi_kick_event_all(vscsi);
+
+ /* We need to know how many segments before we allocate. */
+ sg_elems = virtscsi_config_get(vdev, seg_max) ?: 1;
+
+ for (i = 0; i < num_targets; i++) {
+ vscsi->tgt[i] = virtscsi_alloc_tgt(vdev, sg_elems);
+ if (!vscsi->tgt[i]) {
+ err = -ENOMEM;
+ goto out;
+ }
+ }
+ err = 0;
+
+out:
+ if (err)
+ virtscsi_remove_vqs(vdev);
+ return err;
}
static int __devinit virtscsi_probe(struct virtio_device *vdev)
@@ -443,31 +652,25 @@ static int __devinit virtscsi_probe(struct virtio_device *vdev)
struct Scsi_Host *shost;
struct virtio_scsi *vscsi;
int err;
- u32 sg_elems;
+ u32 sg_elems, num_targets;
u32 cmd_per_lun;
- /* We need to know how many segments before we allocate.
- * We need an extra sg elements at head and tail.
- */
- sg_elems = virtscsi_config_get(vdev, seg_max) ?: 1;
-
/* Allocate memory and link the structs together. */
+ num_targets = virtscsi_config_get(vdev, max_target) + 1;
shost = scsi_host_alloc(&virtscsi_host_template,
- sizeof(*vscsi) + sizeof(vscsi->sg[0]) * (sg_elems + 2));
+ sizeof(*vscsi)
+ + num_targets * sizeof(struct virtio_scsi_target_state));
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;
vdev->priv = shost;
- /* Random initializations. */
- spin_lock_init(&vscsi->vq_lock);
- sg_init_table(vscsi->sg, sg_elems + 2);
-
- err = virtscsi_init(vdev, vscsi);
+ err = virtscsi_init(vdev, vscsi, num_targets);
if (err)
goto virtscsi_init_failed;
@@ -475,15 +678,16 @@ static int __devinit virtscsi_probe(struct virtio_device *vdev)
shost->cmd_per_lun = min_t(u32, cmd_per_lun, shost->can_queue);
shost->max_sectors = virtscsi_config_get(vdev, max_sectors) ?: 0xFFFF;
shost->max_lun = virtscsi_config_get(vdev, max_lun) + 1;
- shost->max_id = virtscsi_config_get(vdev, max_target) + 1;
+ 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(shost);
-
+ /*
+ * 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:
@@ -493,17 +697,13 @@ virtscsi_init_failed:
return err;
}
-static void virtscsi_remove_vqs(struct virtio_device *vdev)
-{
- /* Stop all the virtqueues. */
- vdev->config->reset(vdev);
-
- vdev->config->del_vqs(vdev);
-}
-
static void __devexit 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);
@@ -523,7 +723,7 @@ 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);
+ return virtscsi_init(vdev, vscsi, sh->max_id);
}
#endif
@@ -532,11 +732,18 @@ static struct virtio_device_id id_table[] = {
{ 0 },
};
+static unsigned int features[] = {
+ VIRTIO_SCSI_F_HOTPLUG
+};
+
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,