diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2012-07-27 18:14:26 -0400 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2012-07-27 18:14:26 -0400 |
commit | cea8f46c36c3f82860b038aa23a46e16757666ba (patch) | |
tree | e09dc37d2b6880d86dac09afbc0c686139d86df0 /arch/arm/lib/delay.c | |
parent | c1e7179a38919f02dd950801529176b72f5e5a8a (diff) | |
parent | 91b006def384d8f07f9f324ab211fefe2b085c90 (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/lib/delay.c')
-rw-r--r-- | arch/arm/lib/delay.c | 71 |
1 files changed, 71 insertions, 0 deletions
diff --git a/arch/arm/lib/delay.c b/arch/arm/lib/delay.c new file mode 100644 index 000000000000..d6dacc69254e --- /dev/null +++ b/arch/arm/lib/delay.c | |||
@@ -0,0 +1,71 @@ | |||
1 | /* | ||
2 | * Delay loops based on the OpenRISC implementation. | ||
3 | * | ||
4 | * Copyright (C) 2012 ARM Limited | ||
5 | * | ||
6 | * This program is free software; you can redistribute it and/or modify | ||
7 | * it under the terms of the GNU General Public License version 2 as | ||
8 | * published by the Free Software Foundation. | ||
9 | * | ||
10 | * This program is distributed in the hope that it will be useful, | ||
11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | ||
13 | * GNU General Public License for more details. | ||
14 | * | ||
15 | * You should have received a copy of the GNU General Public License | ||
16 | * along with this program; if not, write to the Free Software | ||
17 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | ||
18 | * | ||
19 | * Author: Will Deacon <will.deacon@arm.com> | ||
20 | */ | ||
21 | |||
22 | #include <linux/delay.h> | ||
23 | #include <linux/init.h> | ||
24 | #include <linux/kernel.h> | ||
25 | #include <linux/module.h> | ||
26 | #include <linux/timex.h> | ||
27 | |||
28 | /* | ||
29 | * Default to the loop-based delay implementation. | ||
30 | */ | ||
31 | struct arm_delay_ops arm_delay_ops = { | ||
32 | .delay = __loop_delay, | ||
33 | .const_udelay = __loop_const_udelay, | ||
34 | .udelay = __loop_udelay, | ||
35 | }; | ||
36 | |||
37 | #ifdef ARCH_HAS_READ_CURRENT_TIMER | ||
38 | static void __timer_delay(unsigned long cycles) | ||
39 | { | ||
40 | cycles_t start = get_cycles(); | ||
41 | |||
42 | while ((get_cycles() - start) < cycles) | ||
43 | cpu_relax(); | ||
44 | } | ||
45 | |||
46 | static void __timer_const_udelay(unsigned long xloops) | ||
47 | { | ||
48 | unsigned long long loops = xloops; | ||
49 | loops *= loops_per_jiffy; | ||
50 | __timer_delay(loops >> UDELAY_SHIFT); | ||
51 | } | ||
52 | |||
53 | static void __timer_udelay(unsigned long usecs) | ||
54 | { | ||
55 | __timer_const_udelay(usecs * UDELAY_MULT); | ||
56 | } | ||
57 | |||
58 | void __init init_current_timer_delay(unsigned long freq) | ||
59 | { | ||
60 | pr_info("Switching to timer-based delay loop\n"); | ||
61 | lpj_fine = freq / HZ; | ||
62 | arm_delay_ops.delay = __timer_delay; | ||
63 | arm_delay_ops.const_udelay = __timer_const_udelay; | ||
64 | arm_delay_ops.udelay = __timer_udelay; | ||
65 | } | ||
66 | |||
67 | unsigned long __cpuinit calibrate_delay_is_known(void) | ||
68 | { | ||
69 | return lpj_fine; | ||
70 | } | ||
71 | #endif | ||