virtio: virtio 1.0 cs04 spec compliance for reset

[cascardo/linux.git] / drivers / virtio / virtio_pci_modern.c

diff --git a/drivers/virtio/virtio_pci_modern.c b/drivers/virtio/virtio_pci_modern.c
index c0c11fa..e76bd91 100644 (file)
--- a/drivers/virtio/virtio_pci_modern.c
+++ b/drivers/virtio/virtio_pci_modern.c
@@ -17,6 +17,7 @@
  *
  */
 
+#include <linux/delay.h>
 #define VIRTIO_PCI_NO_LEGACY
 #include "virtio_pci_common.h"
 
@@ -271,9 +272,13 @@ static void vp_reset(struct virtio_device *vdev)
        struct virtio_pci_device *vp_dev = to_vp_device(vdev);
        /* 0 status means a reset. */
        vp_iowrite8(0, &vp_dev->common->device_status);
-       /* Flush out the status write, and flush in device writes,
-        * including MSI-X interrupts, if any. */
-       vp_ioread8(&vp_dev->common->device_status);
+       /* After writing 0 to device_status, the driver MUST wait for a read of
+        * device_status to return 0 before reinitializing the device.
+        * This will flush out the status write, and flush in device writes,
+        * including MSI-X interrupts, if any.
+        */
+       while (vp_ioread8(&vp_dev->common->device_status))
+               msleep(1);
        /* Flush pending VQ/configuration callbacks. */
        vp_synchronize_vectors(vdev);
 }
@@ -287,31 +292,6 @@ static u16 vp_config_vector(struct virtio_pci_device *vp_dev, u16 vector)
        return vp_ioread16(&vp_dev->common->msix_config);
 }
 
-static size_t vring_pci_size(u16 num)
-{
-       /* We only need a cacheline separation. */
-       return PAGE_ALIGN(vring_size(num, SMP_CACHE_BYTES));
-}
-
-static void *alloc_virtqueue_pages(int *num)
-{
-       void *pages;
-
-       /* TODO: allocate each queue chunk individually */
-       for (; *num && vring_pci_size(*num) > PAGE_SIZE; *num /= 2) {
-               pages = alloc_pages_exact(vring_pci_size(*num),
-                                         GFP_KERNEL|__GFP_ZERO|__GFP_NOWARN);
-               if (pages)
-                       return pages;
-       }
-
-       if (!*num)
-               return NULL;
-
-       /* Try to get a single page. You are my only hope! */
-       return alloc_pages_exact(vring_pci_size(*num), GFP_KERNEL|__GFP_ZERO);
-}
-
 static struct virtqueue *setup_vq(struct virtio_pci_device *vp_dev,
                                  struct virtio_pci_vq_info *info,
                                  unsigned index,
@@ -343,29 +323,22 @@ 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->num = num;
        info->msix_vector = msix_vec;
 
-       info->queue = alloc_virtqueue_pages(&info->num);
-       if (info->queue == NULL)
-               return ERR_PTR(-ENOMEM);
-
        /* create the vring */
-       vq = vring_new_virtqueue(index, info->num,
-                                SMP_CACHE_BYTES, &vp_dev->vdev,
-                                true, info->queue, vp_notify, callback, name);
-       if (!vq) {
-               err = -ENOMEM;
-               goto err_new_queue;
-       }
+       vq = vring_create_virtqueue(index, num,
+                                   SMP_CACHE_BYTES, &vp_dev->vdev,
+                                   true, true, vp_notify, callback, name);
+       if (!vq)
+               return ERR_PTR(-ENOMEM);
 
        /* activate the queue */
-       vp_iowrite16(num, &cfg->queue_size);
-       vp_iowrite64_twopart(virt_to_phys(info->queue),
+       vp_iowrite16(virtqueue_get_vring_size(vq), &cfg->queue_size);
+       vp_iowrite64_twopart(virtqueue_get_desc_addr(vq),
                             &cfg->queue_desc_lo, &cfg->queue_desc_hi);
-       vp_iowrite64_twopart(virt_to_phys(virtqueue_get_avail(vq)),
+       vp_iowrite64_twopart(virtqueue_get_avail_addr(vq),
                             &cfg->queue_avail_lo, &cfg->queue_avail_hi);
-       vp_iowrite64_twopart(virt_to_phys(virtqueue_get_used(vq)),
+       vp_iowrite64_twopart(virtqueue_get_used_addr(vq),
                             &cfg->queue_used_lo, &cfg->queue_used_hi);
 
        if (vp_dev->notify_base) {
@@ -410,8 +383,6 @@ err_assign_vector:
                pci_iounmap(vp_dev->pci_dev, (void __iomem __force *)vq->priv);
 err_map_notify:
        vring_del_virtqueue(vq);
-err_new_queue:
-       free_pages_exact(info->queue, vring_pci_size(info->num));
        return ERR_PTR(err);
 }
 
@@ -456,8 +427,6 @@ static void del_vq(struct virtio_pci_vq_info *info)
                pci_iounmap(vp_dev->pci_dev, (void __force __iomem *)vq->priv);
 
        vring_del_virtqueue(vq);
-
-       free_pages_exact(info->queue, vring_pci_size(info->num));
 }
 
 static const struct virtio_config_ops virtio_pci_config_nodev_ops = {
@@ -641,6 +610,13 @@ int virtio_pci_modern_probe(struct virtio_pci_device *vp_dev)
                return -EINVAL;
        }
 
+       err = dma_set_mask_and_coherent(&pci_dev->dev, DMA_BIT_MASK(64));
+       if (err)
+               err = dma_set_mask_and_coherent(&pci_dev->dev,
+                                               DMA_BIT_MASK(32));
+       if (err)
+               dev_warn(&pci_dev->dev, "Failed to enable 64-bit or 32-bit DMA.  Trying to continue, but this might not work.\n");
+
        /* Device capability is only mandatory for devices that have
         * device-specific configuration.
         */
@@ -679,7 +655,7 @@ int virtio_pci_modern_probe(struct virtio_pci_device *vp_dev)
 
        pci_read_config_dword(pci_dev,
                              notify + offsetof(struct virtio_pci_notify_cap,
-                                               cap.length),
+                                               cap.offset),
                              &notify_offset);
 
        /* We don't know how many VQs we'll map, ahead of the time.