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9513f25056
virtio pci uses word to mean "16 bits". mmio uses it to mean
"32 bits".
To avoid confusion, let's avoid the term in core virtio
altogether. Just say U64 to mean "64 bit".
Fixes: e7d4c1c5a5 ("virtio: introduce extended features")
Cc: Paolo Abeni <pabeni@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Message-ID: <ad53b7b6be87fc524f45abaeca0bb05fb3633397.1764225384.git.mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
90 lines
2.0 KiB
C
90 lines
2.0 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _LINUX_VIRTIO_FEATURES_H
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#define _LINUX_VIRTIO_FEATURES_H
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#include <linux/bits.h>
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#define VIRTIO_FEATURES_U64S 2
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#define VIRTIO_FEATURES_BITS (VIRTIO_FEATURES_U64S * 64)
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#define VIRTIO_BIT(b) BIT_ULL((b) & 0x3f)
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#define VIRTIO_U64(b) ((b) >> 6)
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#define VIRTIO_DECLARE_FEATURES(name) \
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union { \
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u64 name; \
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u64 name##_array[VIRTIO_FEATURES_U64S];\
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}
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static inline bool virtio_features_chk_bit(unsigned int bit)
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{
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if (__builtin_constant_p(bit)) {
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/*
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* Don't care returning the correct value: the build
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* will fail before any bad features access
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*/
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BUILD_BUG_ON(bit >= VIRTIO_FEATURES_BITS);
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} else {
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if (WARN_ON_ONCE(bit >= VIRTIO_FEATURES_BITS))
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return false;
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}
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return true;
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}
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static inline bool virtio_features_test_bit(const u64 *features,
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unsigned int bit)
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{
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return virtio_features_chk_bit(bit) &&
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!!(features[VIRTIO_U64(bit)] & VIRTIO_BIT(bit));
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}
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static inline void virtio_features_set_bit(u64 *features,
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unsigned int bit)
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{
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if (virtio_features_chk_bit(bit))
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features[VIRTIO_U64(bit)] |= VIRTIO_BIT(bit);
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}
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static inline void virtio_features_clear_bit(u64 *features,
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unsigned int bit)
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{
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if (virtio_features_chk_bit(bit))
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features[VIRTIO_U64(bit)] &= ~VIRTIO_BIT(bit);
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}
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static inline void virtio_features_zero(u64 *features)
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{
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memset(features, 0, sizeof(features[0]) * VIRTIO_FEATURES_U64S);
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}
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static inline void virtio_features_from_u64(u64 *features, u64 from)
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{
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virtio_features_zero(features);
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features[0] = from;
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}
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static inline bool virtio_features_equal(const u64 *f1, const u64 *f2)
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{
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int i;
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for (i = 0; i < VIRTIO_FEATURES_U64S; ++i)
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if (f1[i] != f2[i])
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return false;
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return true;
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}
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static inline void virtio_features_copy(u64 *to, const u64 *from)
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{
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memcpy(to, from, sizeof(to[0]) * VIRTIO_FEATURES_U64S);
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}
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static inline void virtio_features_andnot(u64 *to, const u64 *f1, const u64 *f2)
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{
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int i;
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for (i = 0; i < VIRTIO_FEATURES_U64S; i++)
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to[i] = f1[i] & ~f2[i];
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}
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#endif
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