virtio: use u32, not bitmap for features
It seemed like a good idea to use bitmap for features
in struct virtio_device, but it's actually a pain,
and seems to become even more painful when we get more
than 32 feature bits. Just change it to a u32 for now.
Based on patch by Rusty.
Suggested-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c
index cf7a561..8d00aa7 100644
--- a/drivers/char/virtio_console.c
+++ b/drivers/char/virtio_console.c
@@ -355,7 +355,7 @@
*/
if (!portdev->vdev)
return 0;
- return portdev->vdev->features[0] & (1 << VIRTIO_CONSOLE_F_MULTIPORT);
+ return __virtio_test_bit(portdev->vdev, VIRTIO_CONSOLE_F_MULTIPORT);
}
static DEFINE_SPINLOCK(dma_bufs_lock);
diff --git a/drivers/lguest/lguest_device.c b/drivers/lguest/lguest_device.c
index d0a1d8a..97aeb7d 100644
--- a/drivers/lguest/lguest_device.c
+++ b/drivers/lguest/lguest_device.c
@@ -137,14 +137,14 @@
vring_transport_features(vdev);
/*
- * The vdev->feature array is a Linux bitmask: this isn't the same as a
- * the simple array of bits used by lguest devices for features. So we
- * do this slow, manual conversion which is completely general.
+ * Since lguest is currently x86-only, we're little-endian. That
+ * means we could just memcpy. But it's not time critical, and in
+ * case someone copies this code, we do it the slow, obvious way.
*/
memset(out_features, 0, desc->feature_len);
bits = min_t(unsigned, desc->feature_len, sizeof(vdev->features)) * 8;
for (i = 0; i < bits; i++) {
- if (test_bit(i, vdev->features))
+ if (__virtio_test_bit(vdev, i))
out_features[i / 8] |= (1 << (i % 8));
}
diff --git a/drivers/misc/mic/card/mic_virtio.c b/drivers/misc/mic/card/mic_virtio.c
index e647947..4f070ad 100644
--- a/drivers/misc/mic/card/mic_virtio.c
+++ b/drivers/misc/mic/card/mic_virtio.c
@@ -101,7 +101,7 @@
bits = min_t(unsigned, feature_len,
sizeof(vdev->features)) * 8;
for (i = 0; i < bits; i++) {
- if (test_bit(i, vdev->features))
+ if (__virtio_test_bit(vdev, i))
iowrite8(ioread8(&out_features[i / 8]) | (1 << (i % 8)),
&out_features[i / 8]);
}
diff --git a/drivers/remoteproc/remoteproc_virtio.c b/drivers/remoteproc/remoteproc_virtio.c
index a34b506..dafaf38 100644
--- a/drivers/remoteproc/remoteproc_virtio.c
+++ b/drivers/remoteproc/remoteproc_virtio.c
@@ -231,7 +231,7 @@
* Remember the finalized features of our vdev, and provide it
* to the remote processor once it is powered on.
*/
- rsc->gfeatures = vdev->features[0];
+ rsc->gfeatures = vdev->features;
}
static void rproc_virtio_get(struct virtio_device *vdev, unsigned offset,
diff --git a/drivers/s390/kvm/kvm_virtio.c b/drivers/s390/kvm/kvm_virtio.c
index 6431290..fcd312d 100644
--- a/drivers/s390/kvm/kvm_virtio.c
+++ b/drivers/s390/kvm/kvm_virtio.c
@@ -106,7 +106,7 @@
memset(out_features, 0, desc->feature_len);
bits = min_t(unsigned, desc->feature_len, sizeof(vdev->features)) * 8;
for (i = 0; i < bits; i++) {
- if (test_bit(i, vdev->features))
+ if (__virtio_test_bit(vdev, i))
out_features[i / 8] |= (1 << (i % 8));
}
}
diff --git a/drivers/s390/kvm/virtio_ccw.c b/drivers/s390/kvm/virtio_ccw.c
index bda52f1..1dbee95 100644
--- a/drivers/s390/kvm/virtio_ccw.c
+++ b/drivers/s390/kvm/virtio_ccw.c
@@ -701,7 +701,6 @@
{
struct virtio_ccw_device *vcdev = to_vc_device(vdev);
struct virtio_feature_desc *features;
- int i;
struct ccw1 *ccw;
ccw = kzalloc(sizeof(*ccw), GFP_DMA | GFP_KERNEL);
@@ -715,19 +714,15 @@
/* Give virtio_ring a chance to accept features. */
vring_transport_features(vdev);
- for (i = 0; i < sizeof(*vdev->features) / sizeof(features->features);
- i++) {
- int highbits = i % 2 ? 32 : 0;
- features->index = i;
- features->features = cpu_to_le32(vdev->features[i / 2]
- >> highbits);
- /* Write the feature bits to the host. */
- ccw->cmd_code = CCW_CMD_WRITE_FEAT;
- ccw->flags = 0;
- ccw->count = sizeof(*features);
- ccw->cda = (__u32)(unsigned long)features;
- ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_FEAT);
- }
+ features->index = 0;
+ features->features = cpu_to_le32(vdev->features);
+ /* Write the feature bits to the host. */
+ ccw->cmd_code = CCW_CMD_WRITE_FEAT;
+ ccw->flags = 0;
+ ccw->count = sizeof(*features);
+ ccw->cda = (__u32)(unsigned long)features;
+ ccw_io_helper(vcdev, ccw, VIRTIO_CCW_DOING_WRITE_FEAT);
+
out_free:
kfree(features);
kfree(ccw);
diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c
index df598dd..2b9aafb 100644
--- a/drivers/virtio/virtio.c
+++ b/drivers/virtio/virtio.c
@@ -49,9 +49,9 @@
/* We actually represent this as a bitstring, as it could be
* arbitrary length in future. */
- for (i = 0; i < ARRAY_SIZE(dev->features)*BITS_PER_LONG; i++)
+ for (i = 0; i < sizeof(dev->features)*8; i++)
len += sprintf(buf+len, "%c",
- test_bit(i, dev->features) ? '1' : '0');
+ __virtio_test_bit(dev, i) ? '1' : '0');
len += sprintf(buf+len, "\n");
return len;
}
@@ -168,18 +168,18 @@
device_features = dev->config->get_features(dev);
/* Features supported by both device and driver into dev->features. */
- memset(dev->features, 0, sizeof(dev->features));
+ dev->features = 0;
for (i = 0; i < drv->feature_table_size; i++) {
unsigned int f = drv->feature_table[i];
BUG_ON(f >= 32);
if (device_features & (1 << f))
- set_bit(f, dev->features);
+ __virtio_set_bit(dev, f);
}
/* Transport features always preserved to pass to finalize_features. */
for (i = VIRTIO_TRANSPORT_F_START; i < VIRTIO_TRANSPORT_F_END; i++)
if (device_features & (1 << i))
- set_bit(i, dev->features);
+ __virtio_set_bit(dev, i);
dev->config->finalize_features(dev);
diff --git a/drivers/virtio/virtio_mmio.c b/drivers/virtio/virtio_mmio.c
index ef9a165..eb5b0e2 100644
--- a/drivers/virtio/virtio_mmio.c
+++ b/drivers/virtio/virtio_mmio.c
@@ -155,16 +155,12 @@
static void vm_finalize_features(struct virtio_device *vdev)
{
struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
- int i;
/* Give virtio_ring a chance to accept features. */
vring_transport_features(vdev);
- for (i = 0; i < ARRAY_SIZE(vdev->features); i++) {
- writel(i, vm_dev->base + VIRTIO_MMIO_GUEST_FEATURES_SEL);
- writel(vdev->features[i],
- vm_dev->base + VIRTIO_MMIO_GUEST_FEATURES);
- }
+ writel(0, vm_dev->base + VIRTIO_MMIO_GUEST_FEATURES_SEL);
+ writel(vdev->features, vm_dev->base + VIRTIO_MMIO_GUEST_FEATURES);
}
static void vm_get(struct virtio_device *vdev, unsigned offset,
diff --git a/drivers/virtio/virtio_pci.c b/drivers/virtio/virtio_pci.c
index d34ebfa..4e112c1 100644
--- a/drivers/virtio/virtio_pci.c
+++ b/drivers/virtio/virtio_pci.c
@@ -120,8 +120,7 @@
vring_transport_features(vdev);
/* We only support 32 feature bits. */
- BUILD_BUG_ON(ARRAY_SIZE(vdev->features) != 1);
- iowrite32(vdev->features[0], vp_dev->ioaddr+VIRTIO_PCI_GUEST_FEATURES);
+ iowrite32(vdev->features, vp_dev->ioaddr + VIRTIO_PCI_GUEST_FEATURES);
}
/* virtio config->get() implementation */
diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index 3b1f89b..839247c 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -781,7 +781,7 @@
break;
default:
/* We don't understand this bit. */
- clear_bit(i, vdev->features);
+ __virtio_clear_bit(vdev, i);
}
}
}