89 lines
2.1 KiB
C
89 lines
2.1 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_DWORDS 2
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#define VIRTIO_FEATURES_MAX (VIRTIO_FEATURES_DWORDS * 64)
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#define VIRTIO_FEATURES_WORDS (VIRTIO_FEATURES_DWORDS * 2)
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#define VIRTIO_BIT(b) BIT_ULL((b) & 0x3f)
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#define VIRTIO_DWORD(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_DWORDS];\
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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_MAX);
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} else {
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if (WARN_ON_ONCE(bit >= VIRTIO_FEATURES_MAX))
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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_DWORD(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_DWORD(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_DWORD(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_DWORDS);
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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_DWORDS; ++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_DWORDS);
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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_DWORDS; i++)
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to[i] = f1[i] & ~f2[i];
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}
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#endif
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