virtio_pci: remove struct virtio_pci_vq_info

We don't really need struct virtio_pci_vq_info, as most field in there
are redundant:

 - the vq backpointer is not strictly neede to start with
 - the entry in the vqs list is not needed - the generic virtqueue already
   has list, we only need to check if it has a callback to get the same
   semantics
 - we can use a simple array to look up the MSI-X vec if needed.
 - That simple array now also duoble serves to replace the per_vq_vectors
   flag

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

diff --git a/drivers/virtio/virtio_pci_common.c b/drivers/virtio/virtio_pci_common.c
index 186cbab327b8f6ac76ce4cc572a03fdd49410f06..a33767318cbf6b9bb1f02ff2c988c99e7acb3e6e 100644 (file)
--- a/drivers/virtio/virtio_pci_common.c
+++ b/drivers/virtio/virtio_pci_common.c
@@ -62,16 +62,13 @@ static irqreturn_t vp_config_changed(int irq, void *opaque)
 static irqreturn_t vp_vring_interrupt(int irq, void *opaque)
 {
        struct virtio_pci_device *vp_dev = opaque;
-       struct virtio_pci_vq_info *info;
        irqreturn_t ret = IRQ_NONE;
-       unsigned long flags;
+       struct virtqueue *vq;
 
-       spin_lock_irqsave(&vp_dev->lock, flags);
-       list_for_each_entry(info, &vp_dev->virtqueues, node) {
-               if (vring_interrupt(irq, info->vq) == IRQ_HANDLED)
+       list_for_each_entry(vq, &vp_dev->vdev.vqs, list) {
+               if (vq->callback && vring_interrupt(irq, vq) == IRQ_HANDLED)
                        ret = IRQ_HANDLED;
        }
-       spin_unlock_irqrestore(&vp_dev->lock, flags);
 
        return ret;
 }
@@ -167,55 +164,6 @@ error:
        return err;
 }
 
-static struct virtqueue *vp_setup_vq(struct virtio_device *vdev, unsigned index,
-                                    void (*callback)(struct virtqueue *vq),
-                                    const char *name,
-                                    u16 msix_vec)
-{
-       struct virtio_pci_device *vp_dev = to_vp_device(vdev);
-       struct virtio_pci_vq_info *info = kmalloc(sizeof *info, GFP_KERNEL);
-       struct virtqueue *vq;
-       unsigned long flags;
-
-       /* fill out our structure that represents an active queue */
-       if (!info)
-               return ERR_PTR(-ENOMEM);
-
-       vq = vp_dev->setup_vq(vp_dev, info, index, callback, name, msix_vec);
-       if (IS_ERR(vq))
-               goto out_info;
-
-       info->vq = vq;
-       if (callback) {
-               spin_lock_irqsave(&vp_dev->lock, flags);
-               list_add(&info->node, &vp_dev->virtqueues);
-               spin_unlock_irqrestore(&vp_dev->lock, flags);
-       } else {
-               INIT_LIST_HEAD(&info->node);
-       }
-
-       vp_dev->vqs[index] = info;
-       return vq;
-
-out_info:
-       kfree(info);
-       return vq;
-}
-
-static void vp_del_vq(struct virtqueue *vq)
-{
-       struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev);
-       struct virtio_pci_vq_info *info = vp_dev->vqs[vq->index];
-       unsigned long flags;
-
-       spin_lock_irqsave(&vp_dev->lock, flags);
-       list_del(&info->node);
-       spin_unlock_irqrestore(&vp_dev->lock, flags);
-
-       vp_dev->del_vq(info);
-       kfree(info);
-}
-
 /* the config->del_vqs() implementation */
 void vp_del_vqs(struct virtio_device *vdev)
 {
@@ -224,16 +172,15 @@ void vp_del_vqs(struct virtio_device *vdev)
        int i;
 
        list_for_each_entry_safe(vq, n, &vdev->vqs, list) {
-               if (vp_dev->per_vq_vectors) {
-                       int v = vp_dev->vqs[vq->index]->msix_vector;
+               if (vp_dev->msix_vector_map) {
+                       int v = vp_dev->msix_vector_map[vq->index];
 
                        if (v != VIRTIO_MSI_NO_VECTOR)
                                free_irq(pci_irq_vector(vp_dev->pci_dev, v),
                                        vq);
                }
-               vp_del_vq(vq);
+               vp_dev->del_vq(vq);
        }
-       vp_dev->per_vq_vectors = false;
 
        if (vp_dev->intx_enabled) {
                free_irq(vp_dev->pci_dev->irq, vp_dev);
@@ -261,8 +208,8 @@ void vp_del_vqs(struct virtio_device *vdev)
        vp_dev->msix_names = NULL;
        kfree(vp_dev->msix_affinity_masks);
        vp_dev->msix_affinity_masks = NULL;
-       kfree(vp_dev->vqs);
-       vp_dev->vqs = NULL;
+       kfree(vp_dev->msix_vector_map);
+       vp_dev->msix_vector_map = NULL;
 }
 
 static int vp_find_vqs_msix(struct virtio_device *vdev, unsigned nvqs,
@@ -275,10 +222,6 @@ static int vp_find_vqs_msix(struct virtio_device *vdev, unsigned nvqs,
        u16 msix_vec;
        int i, err, nvectors, allocated_vectors;
 
-       vp_dev->vqs = kcalloc(nvqs, sizeof(*vp_dev->vqs), GFP_KERNEL);
-       if (!vp_dev->vqs)
-               return -ENOMEM;
-
        if (per_vq_vectors) {
                /* Best option: one for change interrupt, one per vq. */
                nvectors = 1;
@@ -294,7 +237,13 @@ static int vp_find_vqs_msix(struct virtio_device *vdev, unsigned nvqs,
        if (err)
                goto error_find;
 
-       vp_dev->per_vq_vectors = per_vq_vectors;
+       if (per_vq_vectors) {
+               vp_dev->msix_vector_map = kmalloc_array(nvqs,
+                               sizeof(*vp_dev->msix_vector_map), GFP_KERNEL);
+               if (!vp_dev->msix_vector_map)
+                       goto error_find;
+       }
+
        allocated_vectors = vp_dev->msix_used_vectors;
        for (i = 0; i < nvqs; ++i) {
                if (!names[i]) {
@@ -304,19 +253,25 @@ static int vp_find_vqs_msix(struct virtio_device *vdev, unsigned nvqs,
 
                if (!callbacks[i])
                        msix_vec = VIRTIO_MSI_NO_VECTOR;
-               else if (vp_dev->per_vq_vectors)
+               else if (per_vq_vectors)
                        msix_vec = allocated_vectors++;
                else
                        msix_vec = VP_MSIX_VQ_VECTOR;
-               vqs[i] = vp_setup_vq(vdev, i, callbacks[i], names[i], msix_vec);
+               vqs[i] = vp_dev->setup_vq(vp_dev, i, callbacks[i], names[i],
+                               msix_vec);
                if (IS_ERR(vqs[i])) {
                        err = PTR_ERR(vqs[i]);
                        goto error_find;
                }
 
-               if (!vp_dev->per_vq_vectors || msix_vec == VIRTIO_MSI_NO_VECTOR)
+               if (!per_vq_vectors)
                        continue;
 
+               if (msix_vec == VIRTIO_MSI_NO_VECTOR) {
+                       vp_dev->msix_vector_map[i] = VIRTIO_MSI_NO_VECTOR;
+                       continue;
+               }
+
                /* allocate per-vq irq if available and necessary */
                snprintf(vp_dev->msix_names[msix_vec],
                         sizeof *vp_dev->msix_names,
@@ -326,8 +281,12 @@ static int vp_find_vqs_msix(struct virtio_device *vdev, unsigned nvqs,
                                  vring_interrupt, 0,
                                  vp_dev->msix_names[msix_vec],
                                  vqs[i]);
-               if (err)
+               if (err) {
+                       /* don't free this irq on error */
+                       vp_dev->msix_vector_map[i] = VIRTIO_MSI_NO_VECTOR;
                        goto error_find;
+               }
+               vp_dev->msix_vector_map[i] = msix_vec;
        }
        return 0;
 
@@ -343,23 +302,18 @@ static int vp_find_vqs_intx(struct virtio_device *vdev, unsigned nvqs,
        struct virtio_pci_device *vp_dev = to_vp_device(vdev);
        int i, err;
 
-       vp_dev->vqs = kcalloc(nvqs, sizeof(*vp_dev->vqs), GFP_KERNEL);
-       if (!vp_dev->vqs)
-               return -ENOMEM;
-
        err = request_irq(vp_dev->pci_dev->irq, vp_interrupt, IRQF_SHARED,
                        dev_name(&vdev->dev), vp_dev);
        if (err)
                goto out_del_vqs;
 
        vp_dev->intx_enabled = 1;
-       vp_dev->per_vq_vectors = false;
        for (i = 0; i < nvqs; ++i) {
                if (!names[i]) {
                        vqs[i] = NULL;
                        continue;
                }
-               vqs[i] = vp_setup_vq(vdev, i, callbacks[i], names[i],
+               vqs[i] = vp_dev->setup_vq(vp_dev, i, callbacks[i], names[i],
                                VIRTIO_MSI_NO_VECTOR);
                if (IS_ERR(vqs[i])) {
                        err = PTR_ERR(vqs[i]);
@@ -409,16 +363,15 @@ int vp_set_vq_affinity(struct virtqueue *vq, int cpu)
 {
        struct virtio_device *vdev = vq->vdev;
        struct virtio_pci_device *vp_dev = to_vp_device(vdev);
-       struct virtio_pci_vq_info *info = vp_dev->vqs[vq->index];
-       struct cpumask *mask;
-       unsigned int irq;
 
        if (!vq->callback)
                return -EINVAL;
 
        if (vp_dev->msix_enabled) {
-               mask = vp_dev->msix_affinity_masks[info->msix_vector];
-               irq = pci_irq_vector(vp_dev->pci_dev, info->msix_vector);
+               int vec = vp_dev->msix_vector_map[vq->index];
+               struct cpumask *mask = vp_dev->msix_affinity_masks[vec];
+               unsigned int irq = pci_irq_vector(vp_dev->pci_dev, vec);
+
                if (cpu == -1)
                        irq_set_affinity_hint(irq, NULL);
                else {
@@ -498,8 +451,6 @@ static int virtio_pci_probe(struct pci_dev *pci_dev,
        vp_dev->vdev.dev.parent = &pci_dev->dev;
        vp_dev->vdev.dev.release = virtio_pci_release_dev;
        vp_dev->pci_dev = pci_dev;
-       INIT_LIST_HEAD(&vp_dev->virtqueues);
-       spin_lock_init(&vp_dev->lock);
 
        /* enable the device */
        rc = pci_enable_device(pci_dev);

diff --git a/drivers/virtio/virtio_pci_common.h b/drivers/virtio/virtio_pci_common.h
index b2f666250ae0bf8497e78954ed738b7c5c29afe3..2038887bdf237c437936c2576f72733ad666abb8 100644 (file)
--- a/drivers/virtio/virtio_pci_common.h
+++ b/drivers/virtio/virtio_pci_common.h
@@ -31,17 +31,6 @@
 #include <linux/highmem.h>
 #include <linux/spinlock.h>
 
-struct virtio_pci_vq_info {
-       /* the actual virtqueue */
-       struct virtqueue *vq;
-
-       /* the list node for the virtqueues list */
-       struct list_head node;
-
-       /* MSI-X vector (or none) */
-       unsigned msix_vector;
-};
-
 /* Our device structure */
 struct virtio_pci_device {
        struct virtio_device vdev;
@@ -75,13 +64,6 @@ struct virtio_pci_device {
        /* the IO mapping for the PCI config space */
        void __iomem *ioaddr;
 
-       /* a list of queues so we can dispatch IRQs */
-       spinlock_t lock;
-       struct list_head virtqueues;
-
-       /* array of all queues for house-keeping */
-       struct virtio_pci_vq_info **vqs;
-
        /* MSI-X support */
        int msix_enabled;
        int intx_enabled;
@@ -94,16 +76,15 @@ struct virtio_pci_device {
        /* Vectors allocated, excluding per-vq vectors if any */
        unsigned msix_used_vectors;
 
-       /* Whether we have vector per vq */
-       bool per_vq_vectors;
+       /* Map of per-VQ MSI-X vectors, may be NULL */
+       unsigned *msix_vector_map;
 
        struct virtqueue *(*setup_vq)(struct virtio_pci_device *vp_dev,
-                                     struct virtio_pci_vq_info *info,
                                      unsigned idx,
                                      void (*callback)(struct virtqueue *vq),
                                      const char *name,
                                      u16 msix_vec);
-       void (*del_vq)(struct virtio_pci_vq_info *info);
+       void (*del_vq)(struct virtqueue *vq);
 
        u16 (*config_vector)(struct virtio_pci_device *vp_dev, u16 vector);
 };

diff --git a/drivers/virtio/virtio_pci_legacy.c b/drivers/virtio/virtio_pci_legacy.c
index 6d9e5173d5fa6b7f4da58b48268dd48c7e8c1e1f..47292dad0ff980ad6d7cc52b7d645637561323fc 100644 (file)
--- a/drivers/virtio/virtio_pci_legacy.c
+++ b/drivers/virtio/virtio_pci_legacy.c
@@ -112,7 +112,6 @@ static u16 vp_config_vector(struct virtio_pci_device *vp_dev, u16 vector)
 }
 
 static struct virtqueue *setup_vq(struct virtio_pci_device *vp_dev,
-                                 struct virtio_pci_vq_info *info,
                                  unsigned index,
                                  void (*callback)(struct virtqueue *vq),
                                  const char *name,
@@ -130,8 +129,6 @@ static struct virtqueue *setup_vq(struct virtio_pci_device *vp_dev,
        if (!num || ioread32(vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN))
                return ERR_PTR(-ENOENT);
 
-       info->msix_vector = msix_vec;
-
        /* create the vring */
        vq = vring_create_virtqueue(index, num,
                                    VIRTIO_PCI_VRING_ALIGN, &vp_dev->vdev,
@@ -162,9 +159,8 @@ out_deactivate:
        return ERR_PTR(err);
 }
 
-static void del_vq(struct virtio_pci_vq_info *info)
+static void del_vq(struct virtqueue *vq)
 {
-       struct virtqueue *vq = info->vq;
        struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev);
 
        iowrite16(vq->index, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_SEL);

diff --git a/drivers/virtio/virtio_pci_modern.c b/drivers/virtio/virtio_pci_modern.c
index 4bf7ab375894171acdc8eed942aa51483492bbb2..00e6fc1df407a72a02acdbc783cb299cd197ccfa 100644 (file)
--- a/drivers/virtio/virtio_pci_modern.c
+++ b/drivers/virtio/virtio_pci_modern.c
@@ -293,7 +293,6 @@ static u16 vp_config_vector(struct virtio_pci_device *vp_dev, u16 vector)
 }
 
 static struct virtqueue *setup_vq(struct virtio_pci_device *vp_dev,
-                                 struct virtio_pci_vq_info *info,
                                  unsigned index,
                                  void (*callback)(struct virtqueue *vq),
                                  const char *name,
@@ -323,8 +322,6 @@ static struct virtqueue *setup_vq(struct virtio_pci_device *vp_dev,
        /* get offset of notification word for this vq */
        off = vp_ioread16(&cfg->queue_notify_off);
 
-       info->msix_vector = msix_vec;
-
        /* create the vring */
        vq = vring_create_virtqueue(index, num,
                                    SMP_CACHE_BYTES, &vp_dev->vdev,
@@ -409,9 +406,8 @@ static int vp_modern_find_vqs(struct virtio_device *vdev, unsigned nvqs,
        return 0;
 }
 
-static void del_vq(struct virtio_pci_vq_info *info)
+static void del_vq(struct virtqueue *vq)
 {
-       struct virtqueue *vq = info->vq;
        struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev);
 
        vp_iowrite16(vq->index, &vp_dev->common->queue_select);