summaryrefslogtreecommitdiff
path: root/drivers/scsi
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2013-05-02 14:14:04 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2013-05-02 14:14:04 -0700
commit736a2dd2571ac56b11ed95a7814d838d5311be04 (patch)
treede10d107025970c6e51d5b6faeba799ed4b9caae /drivers/scsi
parent0b2e3b6bb4a415379f16e38fc92db42379be47a1 (diff)
parent01d779a14ef800b74684d9692add4944df052461 (diff)
Merge tag 'virtio-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux
Pull virtio & lguest updates from Rusty Russell: "Lots of virtio work which wasn't quite ready for last merge window. Plus I dived into lguest again, reworking the pagetable code so we can move the switcher page: our fixmaps sometimes take more than 2MB now..." Ugh. Annoying conflicts with the tcm_vhost -> vhost_scsi rename. Hopefully correctly resolved. * tag 'virtio-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux: (57 commits) caif_virtio: Remove bouncing email addresses lguest: improve code readability in lg_cpu_start. virtio-net: fill only rx queues which are being used lguest: map Switcher below fixmap. lguest: cache last cpu we ran on. lguest: map Switcher text whenever we allocate a new pagetable. lguest: don't share Switcher PTE pages between guests. lguest: expost switcher_pages array (as lg_switcher_pages). lguest: extract shadow PTE walking / allocating. lguest: make check_gpte et. al return bool. lguest: assume Switcher text is a single page. lguest: rename switcher_page to switcher_pages. lguest: remove RESERVE_MEM constant. lguest: check vaddr not pgd for Switcher protection. lguest: prepare to make SWITCHER_ADDR a variable. virtio: console: replace EMFILE with EBUSY for already-open port virtio-scsi: reset virtqueue affinity when doing cpu hotplug virtio-scsi: introduce multiqueue support virtio-scsi: push vq lock/unlock into virtscsi_vq_done virtio-scsi: pass struct virtio_scsi to virtqueue completion function ...
Diffstat (limited to 'drivers/scsi')
-rw-r--r--drivers/scsi/virtio_scsi.c487
1 files changed, 346 insertions, 141 deletions
diff --git a/drivers/scsi/virtio_scsi.c b/drivers/scsi/virtio_scsi.c
index 3449a1f8c656..2168258fb2c3 100644
--- a/drivers/scsi/virtio_scsi.c
+++ b/drivers/scsi/virtio_scsi.c
@@ -13,6 +13,8 @@
*
*/
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/mempool.h>
@@ -20,12 +22,14 @@
#include <linux/virtio_ids.h>
#include <linux/virtio_config.h>
#include <linux/virtio_scsi.h>
+#include <linux/cpu.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_cmnd.h>
#define VIRTIO_SCSI_MEMPOOL_SZ 64
#define VIRTIO_SCSI_EVENT_LEN 8
+#define VIRTIO_SCSI_VQ_BASE 2
/* Command queue element */
struct virtio_scsi_cmd {
@@ -57,27 +61,61 @@ struct virtio_scsi_vq {
struct virtqueue *vq;
};
-/* Per-target queue state */
+/*
+ * Per-target queue state.
+ *
+ * This struct holds the data needed by the queue steering policy. When a
+ * target is sent multiple requests, we need to drive them to the same queue so
+ * that FIFO processing order is kept. However, if a target was idle, we can
+ * choose a queue arbitrarily. In this case the queue is chosen according to
+ * the current VCPU, so the driver expects the number of request queues to be
+ * equal to the number of VCPUs. This makes it easy and fast to select the
+ * queue, and also lets the driver optimize the IRQ affinity for the virtqueues
+ * (each virtqueue's affinity is set to the CPU that "owns" the queue).
+ *
+ * An interesting effect of this policy is that only writes to req_vq need to
+ * take the tgt_lock. Read can be done outside the lock because:
+ *
+ * - writes of req_vq only occur when atomic_inc_return(&tgt->reqs) returns 1.
+ * In that case, no other CPU is reading req_vq: even if they were in
+ * virtscsi_queuecommand_multi, they would be spinning on tgt_lock.
+ *
+ * - reads of req_vq only occur when the target is not idle (reqs != 0).
+ * A CPU that enters virtscsi_queuecommand_multi will not modify req_vq.
+ *
+ * Similarly, decrements of reqs are never concurrent with writes of req_vq.
+ * Thus they can happen outside the tgt_lock, provided of course we make reqs
+ * an atomic_t.
+ */
struct virtio_scsi_target_state {
- /* Protects sg. Lock hierarchy is tgt_lock -> vq_lock. */
+ /* This spinlock never held at the same time as vq_lock. */
spinlock_t tgt_lock;
- /* For sglist construction when adding commands to the virtqueue. */
- struct scatterlist sg[];
+ /* Count of outstanding requests. */
+ atomic_t reqs;
+
+ /* Currently active virtqueue for requests sent to this target. */
+ struct virtio_scsi_vq *req_vq;
};
/* 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[];
+ u32 num_queues;
+
+ /* If the affinity hint is set for virtqueues */
+ bool affinity_hint_set;
+
+ /* CPU hotplug notifier */
+ struct notifier_block nb;
+
+ struct virtio_scsi_vq ctrl_vq;
+ struct virtio_scsi_vq event_vq;
+ struct virtio_scsi_vq req_vqs[];
};
static struct kmem_cache *virtscsi_cmd_cache;
@@ -107,11 +145,13 @@ static void virtscsi_compute_resid(struct scsi_cmnd *sc, u32 resid)
*
* Called with vq_lock held.
*/
-static void virtscsi_complete_cmd(void *buf)
+static void virtscsi_complete_cmd(struct virtio_scsi *vscsi, void *buf)
{
struct virtio_scsi_cmd *cmd = buf;
struct scsi_cmnd *sc = cmd->sc;
struct virtio_scsi_cmd_resp *resp = &cmd->resp.cmd;
+ struct virtio_scsi_target_state *tgt =
+ scsi_target(sc->device)->hostdata;
dev_dbg(&sc->device->sdev_gendev,
"cmd %p response %u status %#02x sense_len %u\n",
@@ -166,32 +206,71 @@ static void virtscsi_complete_cmd(void *buf)
mempool_free(cmd, virtscsi_cmd_pool);
sc->scsi_done(sc);
+
+ atomic_dec(&tgt->reqs);
}
-static void virtscsi_vq_done(struct virtqueue *vq, void (*fn)(void *buf))
+static void virtscsi_vq_done(struct virtio_scsi *vscsi,
+ struct virtio_scsi_vq *virtscsi_vq,
+ void (*fn)(struct virtio_scsi *vscsi, void *buf))
{
void *buf;
unsigned int len;
+ unsigned long flags;
+ struct virtqueue *vq = virtscsi_vq->vq;
+ spin_lock_irqsave(&virtscsi_vq->vq_lock, flags);
do {
virtqueue_disable_cb(vq);
while ((buf = virtqueue_get_buf(vq, &len)) != NULL)
- fn(buf);
+ fn(vscsi, buf);
} while (!virtqueue_enable_cb(vq));
+ spin_unlock_irqrestore(&virtscsi_vq->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;
+ int index = vq->index - VIRTIO_SCSI_VQ_BASE;
+ struct virtio_scsi_vq *req_vq = &vscsi->req_vqs[index];
- 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);
+ /*
+ * Read req_vq before decrementing the reqs field in
+ * virtscsi_complete_cmd.
+ *
+ * With barriers:
+ *
+ * CPU #0 virtscsi_queuecommand_multi (CPU #1)
+ * ------------------------------------------------------------
+ * lock vq_lock
+ * read req_vq
+ * read reqs (reqs = 1)
+ * write reqs (reqs = 0)
+ * increment reqs (reqs = 1)
+ * write req_vq
+ *
+ * Possible reordering without barriers:
+ *
+ * CPU #0 virtscsi_queuecommand_multi (CPU #1)
+ * ------------------------------------------------------------
+ * lock vq_lock
+ * read reqs (reqs = 1)
+ * write reqs (reqs = 0)
+ * increment reqs (reqs = 1)
+ * write req_vq
+ * read (wrong) req_vq
+ *
+ * We do not need a full smp_rmb, because req_vq is required to get
+ * to tgt->reqs: tgt is &vscsi->tgt[sc->device->id], where sc is stored
+ * in the virtqueue as the user token.
+ */
+ smp_read_barrier_depends();
+
+ virtscsi_vq_done(vscsi, req_vq, virtscsi_complete_cmd);
};
-static void virtscsi_complete_free(void *buf)
+static void virtscsi_complete_free(struct virtio_scsi *vscsi, void *buf)
{
struct virtio_scsi_cmd *cmd = buf;
@@ -205,11 +284,8 @@ 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);
+ virtscsi_vq_done(vscsi, &vscsi->ctrl_vq, virtscsi_complete_free);
};
static int virtscsi_kick_event(struct virtio_scsi *vscsi,
@@ -223,8 +299,8 @@ static int virtscsi_kick_event(struct virtio_scsi *vscsi,
spin_lock_irqsave(&vscsi->event_vq.vq_lock, flags);
- err = virtqueue_add_buf(vscsi->event_vq.vq, &sg, 0, 1, event_node,
- GFP_ATOMIC);
+ err = virtqueue_add_inbuf(vscsi->event_vq.vq, &sg, 1, event_node,
+ GFP_ATOMIC);
if (!err)
virtqueue_kick(vscsi->event_vq.vq);
@@ -254,7 +330,7 @@ static void virtscsi_cancel_event_work(struct virtio_scsi *vscsi)
}
static void virtscsi_handle_transport_reset(struct virtio_scsi *vscsi,
- struct virtio_scsi_event *event)
+ struct virtio_scsi_event *event)
{
struct scsi_device *sdev;
struct Scsi_Host *shost = virtio_scsi_host(vscsi->vdev);
@@ -332,7 +408,7 @@ static void virtscsi_handle_event(struct work_struct *work)
virtscsi_kick_event(vscsi, event_node);
}
-static void virtscsi_complete_event(void *buf)
+static void virtscsi_complete_event(struct virtio_scsi *vscsi, void *buf)
{
struct virtio_scsi_event_node *event_node = buf;
@@ -344,82 +420,65 @@ static void virtscsi_event_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->event_vq.vq_lock, flags);
- virtscsi_vq_done(vq, virtscsi_complete_event);
- spin_unlock_irqrestore(&vscsi->event_vq.vq_lock, flags);
+ virtscsi_vq_done(vscsi, &vscsi->event_vq, virtscsi_complete_event);
};
-static void virtscsi_map_sgl(struct scatterlist *sg, unsigned int *p_idx,
- struct scsi_data_buffer *sdb)
-{
- struct sg_table *table = &sdb->table;
- struct scatterlist *sg_elem;
- unsigned int idx = *p_idx;
- int i;
-
- for_each_sg(table->sgl, sg_elem, table->nents, i)
- sg[idx++] = *sg_elem;
-
- *p_idx = idx;
-}
-
/**
- * virtscsi_map_cmd - map a scsi_cmd to a virtqueue scatterlist
- * @vscsi : virtio_scsi state
+ * virtscsi_add_cmd - add a virtio_scsi_cmd to a virtqueue
+ * @vq : the struct virtqueue we're talking about
* @cmd : command structure
- * @out_num : number of read-only elements
- * @in_num : number of write-only elements
* @req_size : size of the request buffer
* @resp_size : size of the response buffer
- *
- * Called with tgt_lock held.
+ * @gfp : flags to use for memory allocations
*/
-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)
+static int virtscsi_add_cmd(struct virtqueue *vq,
+ struct virtio_scsi_cmd *cmd,
+ size_t req_size, size_t resp_size, gfp_t gfp)
{
struct scsi_cmnd *sc = cmd->sc;
- struct scatterlist *sg = tgt->sg;
- unsigned int idx = 0;
+ struct scatterlist *sgs[4], req, resp;
+ struct sg_table *out, *in;
+ unsigned out_num = 0, in_num = 0;
+
+ out = in = NULL;
+
+ if (sc && sc->sc_data_direction != DMA_NONE) {
+ if (sc->sc_data_direction != DMA_FROM_DEVICE)
+ out = &scsi_out(sc)->table;
+ if (sc->sc_data_direction != DMA_TO_DEVICE)
+ in = &scsi_in(sc)->table;
+ }
/* Request header. */
- sg_set_buf(&sg[idx++], &cmd->req, req_size);
+ sg_init_one(&req, &cmd->req, req_size);
+ sgs[out_num++] = &req;
/* Data-out buffer. */
- if (sc && sc->sc_data_direction != DMA_FROM_DEVICE)
- virtscsi_map_sgl(sg, &idx, scsi_out(sc));
-
- *out_num = idx;
+ if (out)
+ sgs[out_num++] = out->sgl;
/* Response header. */
- sg_set_buf(&sg[idx++], &cmd->resp, resp_size);
+ sg_init_one(&resp, &cmd->resp, resp_size);
+ sgs[out_num + in_num++] = &resp;
/* Data-in buffer */
- if (sc && sc->sc_data_direction != DMA_TO_DEVICE)
- virtscsi_map_sgl(sg, &idx, scsi_in(sc));
+ if (in)
+ sgs[out_num + in_num++] = in->sgl;
- *in_num = idx - *out_num;
+ return virtqueue_add_sgs(vq, sgs, out_num, in_num, cmd, gfp);
}
-static int virtscsi_kick_cmd(struct virtio_scsi_target_state *tgt,
- struct virtio_scsi_vq *vq,
+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 int out_num, in_num;
unsigned long flags;
int err;
bool needs_kick = false;
- spin_lock_irqsave(&tgt->tgt_lock, flags);
- virtscsi_map_cmd(tgt, cmd, &out_num, &in_num, req_size, resp_size);
-
- spin_lock(&vq->vq_lock);
- err = virtqueue_add_buf(vq->vq, tgt->sg, out_num, in_num, cmd, gfp);
- spin_unlock(&tgt->tgt_lock);
+ 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);
@@ -430,10 +489,10 @@ static int virtscsi_kick_cmd(struct virtio_scsi_target_state *tgt,
return err;
}
-static int virtscsi_queuecommand(struct Scsi_Host *sh, struct scsi_cmnd *sc)
+static int virtscsi_queuecommand(struct virtio_scsi *vscsi,
+ struct virtio_scsi_vq *req_vq,
+ 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;
@@ -467,7 +526,7 @@ 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(tgt, &vscsi->req_vq, cmd,
+ if (virtscsi_kick_cmd(req_vq, cmd,
sizeof cmd->req.cmd, sizeof cmd->resp.cmd,
GFP_ATOMIC) == 0)
ret = 0;
@@ -478,14 +537,62 @@ 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);
- struct virtio_scsi_target_state *tgt = vscsi->tgt[cmd->sc->device->id];
int ret = FAILED;
cmd->comp = &comp;
- if (virtscsi_kick_cmd(tgt, &vscsi->ctrl_vq, cmd,
+ if (virtscsi_kick_cmd(&vscsi->ctrl_vq, cmd,
sizeof cmd->req.tmf, sizeof cmd->resp.tmf,
GFP_NOIO) < 0)
goto out;
@@ -547,18 +654,57 @@ static int virtscsi_abort(struct scsi_cmnd *sc)
return virtscsi_tmf(vscsi, cmd);
}
-static struct scsi_host_template virtscsi_host_template = {
+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",
- .queuecommand = virtscsi_queuecommand,
.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) \
@@ -578,29 +724,69 @@ 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)
+static void __virtscsi_set_affinity(struct virtio_scsi *vscsi, bool affinity)
{
- spin_lock_init(&virtscsi_vq->vq_lock);
- virtscsi_vq->vq = vq;
+ 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 struct virtio_scsi_target_state *virtscsi_alloc_tgt(
- struct virtio_device *vdev, int sg_elems)
+static void virtscsi_set_affinity(struct virtio_scsi *vscsi, bool affinity)
{
- 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);
+ get_online_cpus();
+ __virtscsi_set_affinity(vscsi, affinity);
+ put_online_cpus();
+}
- if (!tgt)
- return NULL;
+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;
+}
- spin_lock_init(&tgt->tgt_lock);
- sg_init_table(tgt->sg, sg_elems + 2);
- return tgt;
+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)
@@ -614,46 +800,56 @@ 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;
+
+ virtscsi_set_affinity(vscsi, false);
/* 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, int num_targets)
+ struct virtio_scsi *vscsi)
{
int err;
- struct virtqueue *vqs[3];
- u32 i, sg_elems;
+ 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;
+ }
- vq_callback_t *callbacks[] = {
- virtscsi_ctrl_done,
- virtscsi_event_done,
- virtscsi_req_done
- };
- const char *names[] = {
- "control",
- "event",
- "request"
- };
+ 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, 3, vqs, callbacks, names);
+ err = vdev->config->find_vqs(vdev, num_vqs, vqs, callbacks, names);
if (err)
- return err;
+ goto out;
virtscsi_init_vq(&vscsi->ctrl_vq, vqs[0]);
virtscsi_init_vq(&vscsi->event_vq, vqs[1]);
- virtscsi_init_vq(&vscsi->req_vq, vqs[2]);
+ 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);
@@ -661,19 +857,12 @@ static int virtscsi_init(struct virtio_device *vdev,
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:
+ kfree(names);
+ kfree(callbacks);
+ kfree(vqs);
if (err)
virtscsi_remove_vqs(vdev);
return err;
@@ -686,13 +875,21 @@ static int virtscsi_probe(struct virtio_device *vdev)
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;
- /* 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)
- + num_targets * sizeof(struct virtio_scsi_target_state));
+ 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;
@@ -700,12 +897,20 @@ static int virtscsi_probe(struct virtio_device *vdev)
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, num_targets);
+ 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;
@@ -743,6 +948,8 @@ static void virtscsi_remove(struct virtio_device *vdev)
scsi_remove_host(shost);
+ unregister_hotcpu_notifier(&vscsi->nb);
+
virtscsi_remove_vqs(vdev);
scsi_host_put(shost);
}
@@ -759,7 +966,7 @@ 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, sh->max_id);
+ return virtscsi_init(vdev, vscsi);
}
#endif
@@ -794,8 +1001,7 @@ static int __init init(void)
virtscsi_cmd_cache = KMEM_CACHE(virtio_scsi_cmd, 0);
if (!virtscsi_cmd_cache) {
- printk(KERN_ERR "kmem_cache_create() for "
- "virtscsi_cmd_cache failed\n");
+ pr_err("kmem_cache_create() for virtscsi_cmd_cache failed\n");
goto error;
}
@@ -804,8 +1010,7 @@ static int __init init(void)
mempool_create_slab_pool(VIRTIO_SCSI_MEMPOOL_SZ,
virtscsi_cmd_cache);
if (!virtscsi_cmd_pool) {
- printk(KERN_ERR "mempool_create() for"
- "virtscsi_cmd_pool failed\n");
+ pr_err("mempool_create() for virtscsi_cmd_pool failed\n");
goto error;
}
ret = register_virtio_driver(&virtio_scsi_driver);