提交 e6536c12 编写于 作者: P Paolo 'Blaisorblade' Giarrusso 提交者: Andi Kleen

[PATCH] x86: comment magic constants in delay.h

For both i386 and x86_64, copy from arch/$ARCH/lib/delay.c comments about the
used magic constants, plus a few other niceties.
Signed-off-by: NPaolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: NAndi Kleen <ak@suse.de>

 include/asm-i386/delay.h   |    5 ++++-
 include/asm-x86_64/delay.h |    5 ++++-
 2 files changed, 8 insertions(+), 2 deletions(-)
上级 b9a8d94a
......@@ -7,6 +7,7 @@
* Delay routines calling functions in arch/i386/lib/delay.c
*/
/* Undefined functions to get compile-time errors */
extern void __bad_udelay(void);
extern void __bad_ndelay(void);
......@@ -15,10 +16,12 @@ extern void __ndelay(unsigned long nsecs);
extern void __const_udelay(unsigned long usecs);
extern void __delay(unsigned long loops);
/* 0x10c7 is 2**32 / 1000000 (rounded up) */
#define udelay(n) (__builtin_constant_p(n) ? \
((n) > 20000 ? __bad_udelay() : __const_udelay((n) * 0x10c7ul)) : \
__udelay(n))
/* 0x5 is 2**32 / 1000000000 (rounded up) */
#define ndelay(n) (__builtin_constant_p(n) ? \
((n) > 20000 ? __bad_ndelay() : __const_udelay((n) * 5ul)) : \
__ndelay(n))
......
......@@ -7,18 +7,21 @@
* Delay routines calling functions in arch/x86_64/lib/delay.c
*/
/* Undefined functions to get compile-time errors */
extern void __bad_udelay(void);
extern void __bad_ndelay(void);
extern void __udelay(unsigned long usecs);
extern void __ndelay(unsigned long usecs);
extern void __ndelay(unsigned long nsecs);
extern void __const_udelay(unsigned long usecs);
extern void __delay(unsigned long loops);
/* 0x10c7 is 2**32 / 1000000 (rounded up) */
#define udelay(n) (__builtin_constant_p(n) ? \
((n) > 20000 ? __bad_udelay() : __const_udelay((n) * 0x10c7ul)) : \
__udelay(n))
/* 0x5 is 2**32 / 1000000000 (rounded up) */
#define ndelay(n) (__builtin_constant_p(n) ? \
((n) > 20000 ? __bad_ndelay() : __const_udelay((n) * 5ul)) : \
__ndelay(n))
......
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