It seemed like a good idea, but it's actually a pain when we get more
than 32 feature bits. Just change it to a u32 for now.
---
drivers/char/virtio_console.c | 2 +-
drivers/lguest/lguest_device.c | 2 +-
drivers/s390/kvm/kvm_virtio.c | 2 +-
drivers/virtio/virtio.c | 10 +++++-----
drivers/virtio/virtio_mmio.c | 8 ++------
drivers/virtio/virtio_pci.c | 3 +--
drivers/virtio/virtio_ring.c | 2 +-
include/linux/virtio.h | 3 +--
include/linux/virtio_config.h | 2 +-
tools/virtio/linux/virtio.h | 18 ++----------------
tools/virtio/virtio_test.c | 5 ++---
11 files changed, 18 insertions(+), 39 deletions(-)
diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c
--- a/drivers/char/virtio_console.c
+++ b/drivers/char/virtio_console.c
@@ -331,7 +331,7 @@ static inline bool use_multiport(struct
*/
if (!portdev->vdev)
return 0;
- return portdev->vdev->features[0] & (1 << VIRTIO_CONSOLE_F_MULTIPORT);
+ return portdev->vdev->features & (1 << VIRTIO_CONSOLE_F_MULTIPORT);
}
static void free_buf(struct port_buffer *buf)
diff --git a/drivers/lguest/lguest_device.c b/drivers/lguest/lguest_device.c
--- a/drivers/lguest/lguest_device.c
+++ b/drivers/lguest/lguest_device.c
@@ -144,7 +144,7 @@ static void lg_finalize_features(struct
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 (vdev->features & (1 << i))
out_features[i / 8] |= (1 << (i % 8));
}
diff --git a/drivers/s390/kvm/kvm_virtio.c b/drivers/s390/kvm/kvm_virtio.c
--- a/drivers/s390/kvm/kvm_virtio.c
+++ b/drivers/s390/kvm/kvm_virtio.c
@@ -105,7 +105,7 @@ static void kvm_finalize_features(struct
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 (vdev->features & (1 << i))
out_features[i / 8] |= (1 << (i % 8));
}
}
diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c
--- a/drivers/virtio/virtio.c
+++ b/drivers/virtio/virtio.c
@@ -41,9 +41,9 @@ static ssize_t features_show(struct devi
/* 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');
+ dev->features & (1ULL << i) ? '1' : '0');
len += sprintf(buf+len, "\n");
return len;
}
@@ -122,18 +122,18 @@ static int virtio_dev_probe(struct devic
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);
+ dev->features |= (1 << 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);
+ dev->features |= (1 << i);
dev->config->finalize_features(dev);
diff --git a/drivers/virtio/virtio_mmio.c b/drivers/virtio/virtio_mmio.c
--- a/drivers/virtio/virtio_mmio.c
+++ b/drivers/virtio/virtio_mmio.c
@@ -112,16 +112,12 @@ static u32 vm_get_features(struct virtio
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
--- a/drivers/virtio/virtio_pci.c
+++ b/drivers/virtio/virtio_pci.c
@@ -121,8 +121,7 @@ static void vp_finalize_features(struct
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
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -685,7 +685,7 @@ void vring_transport_features(struct vir
break;
default:
/* We don't understand this bit. */
- clear_bit(i, vdev->features);
+ vdev->features &= ~(1 << i);
}
}
}
diff --git a/include/linux/virtio.h b/include/linux/virtio.h
--- a/include/linux/virtio.h
+++ b/include/linux/virtio.h
@@ -66,8 +66,7 @@ struct virtio_device {
struct virtio_device_id id;
struct virtio_config_ops *config;
struct list_head vqs;
- /* Note that this is a Linux set_bit-style bitmap. */
- unsigned long features[1];
+ u32 features;
void *priv;
};
diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h
--- a/include/linux/virtio_config.h
+++ b/include/linux/virtio_config.h
@@ -142,7 +142,7 @@ static inline bool virtio_has_feature(co
if (fbit < VIRTIO_TRANSPORT_F_START)
virtio_check_driver_offered_feature(vdev, fbit);
- return test_bit(fbit, vdev->features);
+ return vdev->features & (1 << fbit);
}
/**
diff --git a/tools/virtio/linux/virtio.h b/tools/virtio/linux/virtio.h
--- a/tools/virtio/linux/virtio.h
+++ b/tools/virtio/linux/virtio.h
@@ -131,29 +131,15 @@ static inline void kfree(void *p)
#define BITS_PER_BYTE 8
#define BITS_PER_LONG (sizeof(long) * BITS_PER_BYTE)
#define BIT_MASK(nr) (1UL << ((nr) % BITS_PER_LONG))
-/* TODO: Not atomic as it should be:
- * we don't use this for anything important. */
-static inline void clear_bit(int nr, volatile unsigned long *addr)
-{
- unsigned long mask = BIT_MASK(nr);
- unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
-
- *p &= ~mask;
-}
-
-static inline int test_bit(int nr, const volatile unsigned long *addr)
-{
- return 1UL & (addr[BIT_WORD(nr)] >> (nr & (BITS_PER_LONG-1)));
-}
/* The only feature we care to support */
#define virtio_has_feature(dev, feature) \
- test_bit((feature), (dev)->features)
+ ((dev)->features & (1 << (feature)))
/* end of stubs */
struct virtio_device {
void *dev;
- unsigned long features[1];
+ u32 features;
};
struct virtqueue {
diff --git a/tools/virtio/virtio_test.c b/tools/virtio/virtio_test.c
--- a/tools/virtio/virtio_test.c
+++ b/tools/virtio/virtio_test.c
@@ -55,7 +55,7 @@ void vhost_vq_setup(struct vdev_info *de
{
struct vhost_vring_state state = { .index = info->idx };
struct vhost_vring_file file = { .index = info->idx };
- unsigned long long features = dev->vdev.features[0];
+ unsigned long long features = dev->vdev.features;
struct vhost_vring_addr addr = {
.index = info->idx,
.desc_user_addr = (uint64_t)(unsigned long)info->vring.desc,
@@ -106,8 +106,7 @@ static void vdev_info_init(struct vdev_i
{
int r;
memset(dev, 0, sizeof *dev);
- dev->vdev.features[0] = features;
- dev->vdev.features[1] = features >> 32;
+ dev->vdev.features = features;
dev->buf_size = 1024;
dev->buf = malloc(dev->buf_size);
assert(dev->buf);
--
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