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authorPawel Moll <pawel.moll@arm.com>2015-01-23 14:45:55 +1030
committerRusty Russell <rusty@rustcorp.com.au>2015-01-23 14:57:10 +1030
commit1862ee22ce2e28087299aebb6556a5cdc122d0ef (patch)
treef28c2d0aae6d7e9bde82b269d09da72d727f8522 /drivers/virtio
parent76545f066d2a85464a9f81de2e159b199cc2942b (diff)
downloadlinux-1862ee22ce2e28087299aebb6556a5cdc122d0ef.tar.bz2
virtio-mmio: Update the device to OASIS spec version
This patch add a support for second version of the virtio-mmio device, which follows OASIS "Virtual I/O Device (VIRTIO) Version 1.0" specification. Main changes: 1. The control register symbolic names use the new device/driver nomenclature rather than the old guest/host one. 2. The driver detect the device version (version 1 is the pre-OASIS spec, version 2 is compatible with fist revision of the OASIS spec) and drives the device accordingly. 3. New version uses direct addressing (64 bit address split into two low/high register) instead of the guest page size based one, and addresses each part of the queue (descriptors, available, used) separately. 4. The device activity is now explicitly triggered by writing to the "queue ready" register. 5. Whole 64 bit features are properly handled now (both ways). Signed-off-by: Pawel Moll <pawel.moll@arm.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Diffstat (limited to 'drivers/virtio')
-rw-r--r--drivers/virtio/virtio_mmio.c131
1 files changed, 81 insertions, 50 deletions
diff --git a/drivers/virtio/virtio_mmio.c b/drivers/virtio/virtio_mmio.c
index 00d115b22bd8..cad569890908 100644
--- a/drivers/virtio/virtio_mmio.c
+++ b/drivers/virtio/virtio_mmio.c
@@ -1,7 +1,7 @@
/*
* Virtio memory mapped device driver
*
- * Copyright 2011, ARM Ltd.
+ * Copyright 2011-2014, ARM Ltd.
*
* This module allows virtio devices to be used over a virtual, memory mapped
* platform device.
@@ -50,36 +50,6 @@
*
*
*
- * Registers layout (all 32-bit wide):
- *
- * offset d. name description
- * ------ -- ---------------- -----------------
- *
- * 0x000 R MagicValue Magic value "virt"
- * 0x004 R Version Device version (current max. 1)
- * 0x008 R DeviceID Virtio device ID
- * 0x00c R VendorID Virtio vendor ID
- *
- * 0x010 R HostFeatures Features supported by the host
- * 0x014 W HostFeaturesSel Set of host features to access via HostFeatures
- *
- * 0x020 W GuestFeatures Features activated by the guest
- * 0x024 W GuestFeaturesSel Set of activated features to set via GuestFeatures
- * 0x028 W GuestPageSize Size of guest's memory page in bytes
- *
- * 0x030 W QueueSel Queue selector
- * 0x034 R QueueNumMax Maximum size of the currently selected queue
- * 0x038 W QueueNum Queue size for the currently selected queue
- * 0x03c W QueueAlign Used Ring alignment for the current queue
- * 0x040 RW QueuePFN PFN for the currently selected queue
- *
- * 0x050 W QueueNotify Queue notifier
- * 0x060 R InterruptStatus Interrupt status register
- * 0x064 W InterruptACK Interrupt acknowledge register
- * 0x070 RW Status Device status register
- *
- * 0x100+ RW Device-specific configuration space
- *
* Based on Virtio PCI driver by Anthony Liguori, copyright IBM Corp. 2007
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
@@ -145,11 +115,16 @@ struct virtio_mmio_vq_info {
static u64 vm_get_features(struct virtio_device *vdev)
{
struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
+ u64 features;
+
+ writel(1, vm_dev->base + VIRTIO_MMIO_DEVICE_FEATURES_SEL);
+ features = readl(vm_dev->base + VIRTIO_MMIO_DEVICE_FEATURES);
+ features <<= 32;
- /* TODO: Features > 32 bits */
- writel(0, vm_dev->base + VIRTIO_MMIO_HOST_FEATURES_SEL);
+ writel(0, vm_dev->base + VIRTIO_MMIO_DEVICE_FEATURES_SEL);
+ features |= readl(vm_dev->base + VIRTIO_MMIO_DEVICE_FEATURES);
- return readl(vm_dev->base + VIRTIO_MMIO_HOST_FEATURES);
+ return features;
}
static int vm_finalize_features(struct virtio_device *vdev)
@@ -159,11 +134,20 @@ static int vm_finalize_features(struct virtio_device *vdev)
/* Give virtio_ring a chance to accept features. */
vring_transport_features(vdev);
- /* Make sure we don't have any features > 32 bits! */
- BUG_ON((u32)vdev->features != vdev->features);
+ /* Make sure there is are no mixed devices */
+ if (vm_dev->version == 2 &&
+ !__virtio_test_bit(vdev, VIRTIO_F_VERSION_1)) {
+ dev_err(&vdev->dev, "New virtio-mmio devices (version 2) must provide VIRTIO_F_VERSION_1 feature!\n");
+ return -EINVAL;
+ }
+
+ writel(1, vm_dev->base + VIRTIO_MMIO_DRIVER_FEATURES_SEL);
+ writel((u32)(vdev->features >> 32),
+ vm_dev->base + VIRTIO_MMIO_DRIVER_FEATURES);
- writel(0, vm_dev->base + VIRTIO_MMIO_GUEST_FEATURES_SEL);
- writel(vdev->features, vm_dev->base + VIRTIO_MMIO_GUEST_FEATURES);
+ writel(0, vm_dev->base + VIRTIO_MMIO_DRIVER_FEATURES_SEL);
+ writel((u32)vdev->features,
+ vm_dev->base + VIRTIO_MMIO_DRIVER_FEATURES);
return 0;
}
@@ -275,7 +259,12 @@ static void vm_del_vq(struct virtqueue *vq)
/* Select and deactivate the queue */
writel(index, vm_dev->base + VIRTIO_MMIO_QUEUE_SEL);
- writel(0, vm_dev->base + VIRTIO_MMIO_QUEUE_PFN);
+ if (vm_dev->version == 1) {
+ writel(0, vm_dev->base + VIRTIO_MMIO_QUEUE_PFN);
+ } else {
+ writel(0, vm_dev->base + VIRTIO_MMIO_QUEUE_READY);
+ WARN_ON(readl(vm_dev->base + VIRTIO_MMIO_QUEUE_READY));
+ }
size = PAGE_ALIGN(vring_size(info->num, VIRTIO_MMIO_VRING_ALIGN));
free_pages_exact(info->queue, size);
@@ -312,7 +301,8 @@ static struct virtqueue *vm_setup_vq(struct virtio_device *vdev, unsigned index,
writel(index, vm_dev->base + VIRTIO_MMIO_QUEUE_SEL);
/* Queue shouldn't already be set up. */
- if (readl(vm_dev->base + VIRTIO_MMIO_QUEUE_PFN)) {
+ if (readl(vm_dev->base + (vm_dev->version == 1 ?
+ VIRTIO_MMIO_QUEUE_PFN : VIRTIO_MMIO_QUEUE_READY))) {
err = -ENOENT;
goto error_available;
}
@@ -356,13 +346,6 @@ static struct virtqueue *vm_setup_vq(struct virtio_device *vdev, unsigned index,
info->num /= 2;
}
- /* Activate the queue */
- writel(info->num, vm_dev->base + VIRTIO_MMIO_QUEUE_NUM);
- writel(VIRTIO_MMIO_VRING_ALIGN,
- vm_dev->base + VIRTIO_MMIO_QUEUE_ALIGN);
- writel(virt_to_phys(info->queue) >> PAGE_SHIFT,
- vm_dev->base + VIRTIO_MMIO_QUEUE_PFN);
-
/* Create the vring */
vq = vring_new_virtqueue(index, info->num, VIRTIO_MMIO_VRING_ALIGN, vdev,
true, info->queue, vm_notify, callback, name);
@@ -371,6 +354,33 @@ static struct virtqueue *vm_setup_vq(struct virtio_device *vdev, unsigned index,
goto error_new_virtqueue;
}
+ /* Activate the queue */
+ writel(info->num, vm_dev->base + VIRTIO_MMIO_QUEUE_NUM);
+ if (vm_dev->version == 1) {
+ writel(PAGE_SIZE, vm_dev->base + VIRTIO_MMIO_QUEUE_ALIGN);
+ writel(virt_to_phys(info->queue) >> PAGE_SHIFT,
+ vm_dev->base + VIRTIO_MMIO_QUEUE_PFN);
+ } else {
+ u64 addr;
+
+ addr = virt_to_phys(info->queue);
+ writel((u32)addr, vm_dev->base + VIRTIO_MMIO_QUEUE_DESC_LOW);
+ writel((u32)(addr >> 32),
+ vm_dev->base + VIRTIO_MMIO_QUEUE_DESC_HIGH);
+
+ addr = virt_to_phys(virtqueue_get_avail(vq));
+ writel((u32)addr, vm_dev->base + VIRTIO_MMIO_QUEUE_AVAIL_LOW);
+ writel((u32)(addr >> 32),
+ vm_dev->base + VIRTIO_MMIO_QUEUE_AVAIL_HIGH);
+
+ addr = virt_to_phys(virtqueue_get_used(vq));
+ writel((u32)addr, vm_dev->base + VIRTIO_MMIO_QUEUE_USED_LOW);
+ writel((u32)(addr >> 32),
+ vm_dev->base + VIRTIO_MMIO_QUEUE_USED_HIGH);
+
+ writel(1, vm_dev->base + VIRTIO_MMIO_QUEUE_READY);
+ }
+
vq->priv = info;
info->vq = vq;
@@ -381,7 +391,12 @@ static struct virtqueue *vm_setup_vq(struct virtio_device *vdev, unsigned index,
return vq;
error_new_virtqueue:
- writel(0, vm_dev->base + VIRTIO_MMIO_QUEUE_PFN);
+ if (vm_dev->version == 1) {
+ writel(0, vm_dev->base + VIRTIO_MMIO_QUEUE_PFN);
+ } else {
+ writel(0, vm_dev->base + VIRTIO_MMIO_QUEUE_READY);
+ WARN_ON(readl(vm_dev->base + VIRTIO_MMIO_QUEUE_READY));
+ }
free_pages_exact(info->queue, size);
error_alloc_pages:
kfree(info);
@@ -476,16 +491,32 @@ static int virtio_mmio_probe(struct platform_device *pdev)
/* Check device version */
vm_dev->version = readl(vm_dev->base + VIRTIO_MMIO_VERSION);
- if (vm_dev->version != 1) {
+ if (vm_dev->version < 1 || vm_dev->version > 2) {
dev_err(&pdev->dev, "Version %ld not supported!\n",
vm_dev->version);
return -ENXIO;
}
vm_dev->vdev.id.device = readl(vm_dev->base + VIRTIO_MMIO_DEVICE_ID);
+ if (vm_dev->vdev.id.device == 0) {
+ /*
+ * virtio-mmio device with an ID 0 is a (dummy) placeholder
+ * with no function. End probing now with no error reported.
+ */
+ return -ENODEV;
+ }
vm_dev->vdev.id.vendor = readl(vm_dev->base + VIRTIO_MMIO_VENDOR_ID);
- writel(PAGE_SIZE, vm_dev->base + VIRTIO_MMIO_GUEST_PAGE_SIZE);
+ /* Reject legacy-only IDs for version 2 devices */
+ if (vm_dev->version == 2 &&
+ virtio_device_is_legacy_only(vm_dev->vdev.id)) {
+ dev_err(&pdev->dev, "Version 2 not supported for devices %u!\n",
+ vm_dev->vdev.id.device);
+ return -ENODEV;
+ }
+
+ if (vm_dev->version == 1)
+ writel(PAGE_SIZE, vm_dev->base + VIRTIO_MMIO_GUEST_PAGE_SIZE);
platform_set_drvdata(pdev, vm_dev);