From b9a8d94a47f8a41766f6f7944adfb1d641349903 Mon Sep 17 00:00:00 2001 From: Paolo 'Blaisorblade' Giarrusso Date: Thu, 7 Dec 2006 02:14:07 +0100 Subject: [PATCH] x86-64: Make x86_64 udelay() round up instead of down. Port two patches from i386 to x86_64 delay.c to make sure all rounding is done upward instead of downward. There is no sign in commit messages that the mismatch was done on purpose, and "delay() guarantees sleeping at least for the specified time" is still a valid rule IMHO. The original x86 patches are both from pre-GIT era, i.e.: "[PATCH] round up in __udelay()" in commit 54c7e1f5cc6771ff644d7bc21a2b829308bd126f "[PATCH] add 1 in __const_udelay()" in commit 42c77a9801b8877d8b90f65f75db758822a0bccc (both commits are from converted BK repository to x86_64). AK: fixed gcc warning linux/arch/x86_64/lib/delay.c:43: warning: suggest parentheses around + or - inside shift (did this actually work?) Signed-off-by: Paolo 'Blaisorblade' Giarrusso Signed-off-by: Andi Kleen --- include/asm-x86_64/delay.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/asm-x86_64/delay.h') diff --git a/include/asm-x86_64/delay.h b/include/asm-x86_64/delay.h index 65f64acc5319..40146f611ccb 100644 --- a/include/asm-x86_64/delay.h +++ b/include/asm-x86_64/delay.h @@ -16,7 +16,7 @@ extern void __const_udelay(unsigned long usecs); extern void __delay(unsigned long loops); #define udelay(n) (__builtin_constant_p(n) ? \ - ((n) > 20000 ? __bad_udelay() : __const_udelay((n) * 0x10c6ul)) : \ + ((n) > 20000 ? __bad_udelay() : __const_udelay((n) * 0x10c7ul)) : \ __udelay(n)) #define ndelay(n) (__builtin_constant_p(n) ? \ -- cgit v1.2.3 From e6536c1262c56d302e749ab1b44fdb0b9786327d Mon Sep 17 00:00:00 2001 From: Paolo 'Blaisorblade' Giarrusso Date: Thu, 7 Dec 2006 02:14:07 +0100 Subject: [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: Paolo 'Blaisorblade' Giarrusso Signed-off-by: Andi Kleen include/asm-i386/delay.h | 5 ++++- include/asm-x86_64/delay.h | 5 ++++- 2 files changed, 8 insertions(+), 2 deletions(-) --- include/asm-i386/delay.h | 5 ++++- include/asm-x86_64/delay.h | 5 ++++- 2 files changed, 8 insertions(+), 2 deletions(-) (limited to 'include/asm-x86_64/delay.h') diff --git a/include/asm-i386/delay.h b/include/asm-i386/delay.h index b1c7650dc7b9..9ae5e3782ed8 100644 --- a/include/asm-i386/delay.h +++ b/include/asm-i386/delay.h @@ -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)) diff --git a/include/asm-x86_64/delay.h b/include/asm-x86_64/delay.h index 40146f611ccb..c2669f1f5529 100644 --- a/include/asm-x86_64/delay.h +++ b/include/asm-x86_64/delay.h @@ -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)) -- cgit v1.2.3