90 lines
2.0 KiB
C
90 lines
2.0 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
|
|
#ifndef _LINUX_VIRTIO_FEATURES_H
|
|
#define _LINUX_VIRTIO_FEATURES_H
|
|
|
|
#include <linux/bits.h>
|
|
|
|
#define VIRTIO_FEATURES_U64S 2
|
|
#define VIRTIO_FEATURES_BITS (VIRTIO_FEATURES_U64S * 64)
|
|
|
|
#define VIRTIO_BIT(b) BIT_ULL((b) & 0x3f)
|
|
#define VIRTIO_U64(b) ((b) >> 6)
|
|
|
|
#define VIRTIO_DECLARE_FEATURES(name) \
|
|
union { \
|
|
u64 name; \
|
|
u64 name##_array[VIRTIO_FEATURES_U64S];\
|
|
}
|
|
|
|
static inline bool virtio_features_chk_bit(unsigned int bit)
|
|
{
|
|
if (__builtin_constant_p(bit)) {
|
|
/*
|
|
* Don't care returning the correct value: the build
|
|
* will fail before any bad features access
|
|
*/
|
|
BUILD_BUG_ON(bit >= VIRTIO_FEATURES_BITS);
|
|
} else {
|
|
if (WARN_ON_ONCE(bit >= VIRTIO_FEATURES_BITS))
|
|
return false;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
static inline bool virtio_features_test_bit(const u64 *features,
|
|
unsigned int bit)
|
|
{
|
|
return virtio_features_chk_bit(bit) &&
|
|
!!(features[VIRTIO_U64(bit)] & VIRTIO_BIT(bit));
|
|
}
|
|
|
|
static inline void virtio_features_set_bit(u64 *features,
|
|
unsigned int bit)
|
|
{
|
|
if (virtio_features_chk_bit(bit))
|
|
features[VIRTIO_U64(bit)] |= VIRTIO_BIT(bit);
|
|
}
|
|
|
|
static inline void virtio_features_clear_bit(u64 *features,
|
|
unsigned int bit)
|
|
{
|
|
if (virtio_features_chk_bit(bit))
|
|
features[VIRTIO_U64(bit)] &= ~VIRTIO_BIT(bit);
|
|
}
|
|
|
|
static inline void virtio_features_zero(u64 *features)
|
|
{
|
|
memset(features, 0, sizeof(features[0]) * VIRTIO_FEATURES_U64S);
|
|
}
|
|
|
|
static inline void virtio_features_from_u64(u64 *features, u64 from)
|
|
{
|
|
virtio_features_zero(features);
|
|
features[0] = from;
|
|
}
|
|
|
|
static inline bool virtio_features_equal(const u64 *f1, const u64 *f2)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < VIRTIO_FEATURES_U64S; ++i)
|
|
if (f1[i] != f2[i])
|
|
return false;
|
|
return true;
|
|
}
|
|
|
|
static inline void virtio_features_copy(u64 *to, const u64 *from)
|
|
{
|
|
memcpy(to, from, sizeof(to[0]) * VIRTIO_FEATURES_U64S);
|
|
}
|
|
|
|
static inline void virtio_features_andnot(u64 *to, const u64 *f1, const u64 *f2)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < VIRTIO_FEATURES_U64S; i++)
|
|
to[i] = f1[i] & ~f2[i];
|
|
}
|
|
|
|
#endif
|