virtio-mmio: Remove virtqueue list from mmio device

The MMIO transport implementation creates a list of virtqueues for a
virtio device, while the same is already available in the struct
virtio_device.

Don't create a duplicate list, and use the other one instead.

While at it, fix the virtio_device_for_each_vq() macro to accept an
argument like "&vm_dev->vdev" (which currently fails to build).

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Message-Id: <3e56c6f74002987e22f364d883cbad177cd9ad9c.1747827066.git.viresh.kumar@linaro.org>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>

Author: vireshk

drivers/virtio/virtio_mmio.c

@@ -65,7 +65,6 @@
 #include <linux/platform_device.h>
 #include <linux/pm.h>
 #include <linux/slab.h>
-#include <linux/spinlock.h>
 #include <linux/virtio.h>
 #include <linux/virtio_config.h>
 #include <uapi/linux/virtio_mmio.h>
@@ -88,22 +87,8 @@ struct virtio_mmio_device {
 
 	void __iomem *base;
 	unsigned long version;
-
-	/* a list of queues so we can dispatch IRQs */
-	spinlock_t lock;
-	struct list_head virtqueues;
-};
-
-struct virtio_mmio_vq_info {
-	/* the actual virtqueue */
-	struct virtqueue *vq;
-
-	/* the list node for the virtqueues list */
-	struct list_head node;
 };
 
-
-
 /* Configuration interface */
 
 static u64 vm_get_features(struct virtio_device *vdev)
@@ -300,9 +285,8 @@ static bool vm_notify_with_data(struct virtqueue *vq)
 static irqreturn_t vm_interrupt(int irq, void *opaque)
 {
 	struct virtio_mmio_device *vm_dev = opaque;
-	struct virtio_mmio_vq_info *info;
+	struct virtqueue *vq;
 	unsigned long status;
-	unsigned long flags;
 	irqreturn_t ret = IRQ_NONE;
 
 	/* Read and acknowledge interrupts */
@@ -315,10 +299,8 @@ static irqreturn_t vm_interrupt(int irq, void *opaque)
 	}
 
 	if (likely(status & VIRTIO_MMIO_INT_VRING)) {
-		spin_lock_irqsave(&vm_dev->lock, flags);
-		list_for_each_entry(info, &vm_dev->virtqueues, node)
-			ret |= vring_interrupt(irq, info->vq);
-		spin_unlock_irqrestore(&vm_dev->lock, flags);
+		virtio_device_for_each_vq(&vm_dev->vdev, vq)
+			ret |= vring_interrupt(irq, vq);
 	}
 
 	return ret;
@@ -329,14 +311,8 @@ static irqreturn_t vm_interrupt(int irq, void *opaque)
 static void vm_del_vq(struct virtqueue *vq)
 {
 	struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vq->vdev);
-	struct virtio_mmio_vq_info *info = vq->priv;
-	unsigned long flags;
 	unsigned int index = vq->index;
 
-	spin_lock_irqsave(&vm_dev->lock, flags);
-	list_del(&info->node);
-	spin_unlock_irqrestore(&vm_dev->lock, flags);
-
 	/* Select and deactivate the queue */
 	writel(index, vm_dev->base + VIRTIO_MMIO_QUEUE_SEL);
 	if (vm_dev->version == 1) {
@@ -347,8 +323,6 @@ static void vm_del_vq(struct virtqueue *vq)
 	}
 
 	vring_del_virtqueue(vq);
-
-	kfree(info);
 }
 
 static void vm_del_vqs(struct virtio_device *vdev)
@@ -375,9 +349,7 @@ static struct virtqueue *vm_setup_vq(struct virtio_device *vdev, unsigned int in
 {
 	struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
 	bool (*notify)(struct virtqueue *vq);
-	struct virtio_mmio_vq_info *info;
 	struct virtqueue *vq;
-	unsigned long flags;
 	unsigned int num;
 	int err;
 
@@ -399,13 +371,6 @@ static struct virtqueue *vm_setup_vq(struct virtio_device *vdev, unsigned int in
 		goto error_available;
 	}
 
-	/* Allocate and fill out our active queue description */
-	info = kmalloc(sizeof(*info), GFP_KERNEL);
-	if (!info) {
-		err = -ENOMEM;
-		goto error_kmalloc;
-	}
-
 	num = readl(vm_dev->base + VIRTIO_MMIO_QUEUE_NUM_MAX);
 	if (num == 0) {
 		err = -ENOENT;
@@ -463,13 +428,6 @@ static struct virtqueue *vm_setup_vq(struct virtio_device *vdev, unsigned int in
 		writel(1, vm_dev->base + VIRTIO_MMIO_QUEUE_READY);
 	}
 
-	vq->priv = info;
-	info->vq = vq;
-
-	spin_lock_irqsave(&vm_dev->lock, flags);
-	list_add(&info->node, &vm_dev->virtqueues);
-	spin_unlock_irqrestore(&vm_dev->lock, flags);
-
 	return vq;
 
 error_bad_pfn:
@@ -481,8 +439,6 @@ static struct virtqueue *vm_setup_vq(struct virtio_device *vdev, unsigned int in
 		writel(0, vm_dev->base + VIRTIO_MMIO_QUEUE_READY);
 		WARN_ON(readl(vm_dev->base + VIRTIO_MMIO_QUEUE_READY));
 	}
-	kfree(info);
-error_kmalloc:
 error_available:
 	return ERR_PTR(err);
 }
@@ -627,8 +583,6 @@ static int virtio_mmio_probe(struct platform_device *pdev)
 	vm_dev->vdev.dev.release = virtio_mmio_release_dev;
 	vm_dev->vdev.config = &virtio_mmio_config_ops;
 	vm_dev->pdev = pdev;
-	INIT_LIST_HEAD(&vm_dev->virtqueues);
-	spin_lock_init(&vm_dev->lock);
 
 	vm_dev->base = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(vm_dev->base)) {

include/linux/virtio.h

@@ -196,7 +196,7 @@ int virtio_device_reset_done(struct virtio_device *dev);
 size_t virtio_max_dma_size(const struct virtio_device *vdev);
 
 #define virtio_device_for_each_vq(vdev, vq) \
-	list_for_each_entry(vq, &vdev->vqs, list)
+	list_for_each_entry(vq, &(vdev)->vqs, list)
 
 /**
  * struct virtio_driver - operations for a virtio I/O driver