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authorLinus Torvalds <torvalds@linux-foundation.org>2012-07-27 18:14:26 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2012-07-27 18:14:26 -0400
commitcea8f46c36c3f82860b038aa23a46e16757666ba (patch)
treee09dc37d2b6880d86dac09afbc0c686139d86df0 /arch/arm/include/asm/delay.h
parentc1e7179a38919f02dd950801529176b72f5e5a8a (diff)
parent91b006def384d8f07f9f324ab211fefe2b085c90 (diff)
Merge branch 'for-linus' of git://git.linaro.org/people/rmk/linux-arm
Pull ARM updates from Russell King: "First ARM push of this merge window, post me coming back from holiday. This is what has been in linux-next for the last few weeks. Not much to say which isn't described by the commit summaries." * 'for-linus' of git://git.linaro.org/people/rmk/linux-arm: (32 commits) ARM: 7463/1: topology: Update cpu_power according to DT information ARM: 7462/1: topology: factorize the update of sibling masks ARM: 7461/1: topology: Add arch_scale_freq_power function ARM: 7456/1: ptrace: provide separate functions for tracing syscall {entry,exit} ARM: 7455/1: audit: move syscall auditing until after ptrace SIGTRAP handling ARM: 7454/1: entry: don't bother with syscall tracing on ret_from_fork path ARM: 7453/1: audit: only allow syscall auditing for pure EABI userspace ARM: 7452/1: delay: allow timer-based delay implementation to be selected ARM: 7451/1: arch timer: implement read_current_timer and get_cycles ARM: 7450/1: dcache: select DCACHE_WORD_ACCESS for little-endian ARMv6+ CPUs ARM: 7449/1: use generic strnlen_user and strncpy_from_user functions ARM: 7448/1: perf: remove arm_perf_pmu_ids global enumeration ARM: 7447/1: rwlocks: remove unused branch labels from trylock routines ARM: 7446/1: spinlock: use ticket algorithm for ARMv6+ locking implementation ARM: 7445/1: mm: update CONTEXTIDR register to contain PID of current process ARM: 7444/1: kernel: add arch-timer C3STOP feature ARM: 7460/1: remove asm/locks.h ARM: 7439/1: head.S: simplify initial page table mapping ARM: 7437/1: zImage: Allow DTB command line concatenation with ATAG_CMDLINE ARM: 7436/1: Do not map the vectors page as write-through on UP systems ...
Diffstat (limited to 'arch/arm/include/asm/delay.h')
-rw-r--r--arch/arm/include/asm/delay.h32
1 files changed, 25 insertions, 7 deletions
diff --git a/arch/arm/include/asm/delay.h b/arch/arm/include/asm/delay.h
index b2deda181549..dc6145120de3 100644
--- a/arch/arm/include/asm/delay.h
+++ b/arch/arm/include/asm/delay.h
@@ -6,9 +6,22 @@
6#ifndef __ASM_ARM_DELAY_H 6#ifndef __ASM_ARM_DELAY_H
7#define __ASM_ARM_DELAY_H 7#define __ASM_ARM_DELAY_H
8 8
9#include <asm/memory.h>
9#include <asm/param.h> /* HZ */ 10#include <asm/param.h> /* HZ */
10 11
11extern void __delay(int loops); 12#define MAX_UDELAY_MS 2
13#define UDELAY_MULT ((UL(2199023) * HZ) >> 11)
14#define UDELAY_SHIFT 30
15
16#ifndef __ASSEMBLY__
17
18extern struct arm_delay_ops {
19 void (*delay)(unsigned long);
20 void (*const_udelay)(unsigned long);
21 void (*udelay)(unsigned long);
22} arm_delay_ops;
23
24#define __delay(n) arm_delay_ops.delay(n)
12 25
13/* 26/*
14 * This function intentionally does not exist; if you see references to 27 * This function intentionally does not exist; if you see references to
@@ -23,22 +36,27 @@ extern void __bad_udelay(void);
23 * division by multiplication: you don't have to worry about 36 * division by multiplication: you don't have to worry about
24 * loss of precision. 37 * loss of precision.
25 * 38 *
26 * Use only for very small delays ( < 1 msec). Should probably use a 39 * Use only for very small delays ( < 2 msec). Should probably use a
27 * lookup table, really, as the multiplications take much too long with 40 * lookup table, really, as the multiplications take much too long with
28 * short delays. This is a "reasonable" implementation, though (and the 41 * short delays. This is a "reasonable" implementation, though (and the
29 * first constant multiplications gets optimized away if the delay is 42 * first constant multiplications gets optimized away if the delay is
30 * a constant) 43 * a constant)
31 */ 44 */
32extern void __udelay(unsigned long usecs); 45#define __udelay(n) arm_delay_ops.udelay(n)
33extern void __const_udelay(unsigned long); 46#define __const_udelay(n) arm_delay_ops.const_udelay(n)
34
35#define MAX_UDELAY_MS 2
36 47
37#define udelay(n) \ 48#define udelay(n) \
38 (__builtin_constant_p(n) ? \ 49 (__builtin_constant_p(n) ? \
39 ((n) > (MAX_UDELAY_MS * 1000) ? __bad_udelay() : \ 50 ((n) > (MAX_UDELAY_MS * 1000) ? __bad_udelay() : \
40 __const_udelay((n) * ((2199023U*HZ)>>11))) : \ 51 __const_udelay((n) * UDELAY_MULT)) : \
41 __udelay(n)) 52 __udelay(n))
42 53
54/* Loop-based definitions for assembly code. */
55extern void __loop_delay(unsigned long loops);
56extern void __loop_udelay(unsigned long usecs);
57extern void __loop_const_udelay(unsigned long);
58
59#endif /* __ASSEMBLY__ */
60
43#endif /* defined(_ARM_DELAY_H) */ 61#endif /* defined(_ARM_DELAY_H) */
44 62