linux-stable/include/linux/kdev_t.h
Josh Poimboeuf aa8c7db494 kdev_t: always inline major/minor helper functions
Silly GCC doesn't always inline these trivial functions.

Fixes the following warning:

  arch/x86/kernel/sys_ia32.o: warning: objtool: cp_stat64()+0xd8: call to new_encode_dev() with UACCESS enabled

Link: https://lkml.kernel.org/r/984353b44a4484d86ba9f73884b7306232e25e30.1608737428.git.jpoimboe@redhat.com
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org>	[build-tested]
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-12-29 15:36:49 -08:00

83 lines
1.8 KiB
C

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