84 строки
1.8 KiB
C
84 строки
1.8 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _LINUX_KDEV_T_H
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#define _LINUX_KDEV_T_H
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#include <uapi/linux/kdev_t.h>
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#define MINORBITS 20
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#define MINORMASK ((1U << MINORBITS) - 1)
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#define MAJOR(dev) ((unsigned int) ((dev) >> MINORBITS))
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#define MINOR(dev) ((unsigned int) ((dev) & MINORMASK))
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#define MKDEV(ma,mi) (((ma) << MINORBITS) | (mi))
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#define print_dev_t(buffer, dev) \
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sprintf((buffer), "%u:%u\n", MAJOR(dev), MINOR(dev))
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#define format_dev_t(buffer, dev) \
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({ \
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sprintf(buffer, "%u:%u", MAJOR(dev), MINOR(dev)); \
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buffer; \
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})
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/* acceptable for old filesystems */
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static __always_inline bool old_valid_dev(dev_t dev)
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{
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return MAJOR(dev) < 256 && MINOR(dev) < 256;
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}
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static __always_inline u16 old_encode_dev(dev_t dev)
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{
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return (MAJOR(dev) << 8) | MINOR(dev);
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}
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static __always_inline dev_t old_decode_dev(u16 val)
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{
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return MKDEV((val >> 8) & 255, val & 255);
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}
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static __always_inline u32 new_encode_dev(dev_t dev)
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{
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unsigned major = MAJOR(dev);
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unsigned minor = MINOR(dev);
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return (minor & 0xff) | (major << 8) | ((minor & ~0xff) << 12);
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}
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static __always_inline dev_t new_decode_dev(u32 dev)
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{
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unsigned major = (dev & 0xfff00) >> 8;
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unsigned minor = (dev & 0xff) | ((dev >> 12) & 0xfff00);
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return MKDEV(major, minor);
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}
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static __always_inline u64 huge_encode_dev(dev_t dev)
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{
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return new_encode_dev(dev);
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}
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static __always_inline dev_t huge_decode_dev(u64 dev)
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{
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return new_decode_dev(dev);
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}
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static __always_inline int sysv_valid_dev(dev_t dev)
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{
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return MAJOR(dev) < (1<<14) && MINOR(dev) < (1<<18);
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}
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static __always_inline u32 sysv_encode_dev(dev_t dev)
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{
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return MINOR(dev) | (MAJOR(dev) << 18);
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}
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static __always_inline unsigned sysv_major(u32 dev)
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{
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return (dev >> 18) & 0x3fff;
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}
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static __always_inline unsigned sysv_minor(u32 dev)
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{
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return dev & 0x3ffff;
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}
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#endif
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