diff options
Diffstat (limited to 'arch/arm')
| -rw-r--r-- | arch/arm/include/asm/delay.h | 32 | ||||
| -rw-r--r-- | arch/arm/kernel/arch_timer.c | 3 | ||||
| -rw-r--r-- | arch/arm/kernel/armksyms.c | 3 | ||||
| -rw-r--r-- | arch/arm/lib/Makefile | 2 | ||||
| -rw-r--r-- | arch/arm/lib/delay-loop.S (renamed from arch/arm/lib/delay.S) | 20 | ||||
| -rw-r--r-- | arch/arm/lib/delay.c | 71 | ||||
| -rw-r--r-- | arch/arm/mach-sa1100/sleep.S | 8 |
7 files changed, 114 insertions, 25 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 @@ #ifndef __ASM_ARM_DELAY_H #define __ASM_ARM_DELAY_H +#include <asm/memory.h> #include <asm/param.h> /* HZ */ -extern void __delay(int loops); +#define MAX_UDELAY_MS 2 +#define UDELAY_MULT ((UL(2199023) * HZ) >> 11) +#define UDELAY_SHIFT 30 + +#ifndef __ASSEMBLY__ + +extern struct arm_delay_ops { + void (*delay)(unsigned long); + void (*const_udelay)(unsigned long); + void (*udelay)(unsigned long); +} arm_delay_ops; + +#define __delay(n) arm_delay_ops.delay(n) /* * This function intentionally does not exist; if you see references to @@ -23,22 +36,27 @@ extern void __bad_udelay(void); * division by multiplication: you don't have to worry about * loss of precision. * - * Use only for very small delays ( < 1 msec). Should probably use a + * Use only for very small delays ( < 2 msec). Should probably use a * lookup table, really, as the multiplications take much too long with * short delays. This is a "reasonable" implementation, though (and the * first constant multiplications gets optimized away if the delay is * a constant) */ -extern void __udelay(unsigned long usecs); -extern void __const_udelay(unsigned long); - -#define MAX_UDELAY_MS 2 +#define __udelay(n) arm_delay_ops.udelay(n) +#define __const_udelay(n) arm_delay_ops.const_udelay(n) #define udelay(n) \ (__builtin_constant_p(n) ? \ ((n) > (MAX_UDELAY_MS * 1000) ? __bad_udelay() : \ - __const_udelay((n) * ((2199023U*HZ)>>11))) : \ + __const_udelay((n) * UDELAY_MULT)) : \ __udelay(n)) +/* Loop-based definitions for assembly code. */ +extern void __loop_delay(unsigned long loops); +extern void __loop_udelay(unsigned long usecs); +extern void __loop_const_udelay(unsigned long); + +#endif /* __ASSEMBLY__ */ + #endif /* defined(_ARM_DELAY_H) */ diff --git a/arch/arm/kernel/arch_timer.c b/arch/arm/kernel/arch_timer.c index dbbeec4f06e2..675cee09c014 100644 --- a/arch/arm/kernel/arch_timer.c +++ b/arch/arm/kernel/arch_timer.c @@ -32,6 +32,8 @@ static int arch_timer_ppi2; static struct clock_event_device __percpu **arch_timer_evt; +extern void init_current_timer_delay(unsigned long freq); + /* * Architected system timer support. */ @@ -304,6 +306,7 @@ static int __init arch_timer_register(void) if (err) goto out_free_irq; + init_current_timer_delay(arch_timer_rate); return 0; out_free_irq: diff --git a/arch/arm/kernel/armksyms.c b/arch/arm/kernel/armksyms.c index b57c75e0b01f..71962284d288 100644 --- a/arch/arm/kernel/armksyms.c +++ b/arch/arm/kernel/armksyms.c @@ -49,8 +49,7 @@ extern void __aeabi_ulcmp(void); extern void fpundefinstr(void); /* platform dependent support */ -EXPORT_SYMBOL(__udelay); -EXPORT_SYMBOL(__const_udelay); +EXPORT_SYMBOL(arm_delay_ops); /* networking */ EXPORT_SYMBOL(csum_partial); diff --git a/arch/arm/lib/Makefile b/arch/arm/lib/Makefile index 992769ae2599..b621114644fd 100644 --- a/arch/arm/lib/Makefile +++ b/arch/arm/lib/Makefile @@ -6,7 +6,7 @@ lib-y := backtrace.o changebit.o csumipv6.o csumpartial.o \ csumpartialcopy.o csumpartialcopyuser.o clearbit.o \ - delay.o findbit.o memchr.o memcpy.o \ + delay.o delay-loop.o findbit.o memchr.o memcpy.o \ memmove.o memset.o memzero.o setbit.o \ strncpy_from_user.o strnlen_user.o \ strchr.o strrchr.o \ diff --git a/arch/arm/lib/delay.S b/arch/arm/lib/delay-loop.S index 3c9a05c8d20b..36b668d8e121 100644 --- a/arch/arm/lib/delay.S +++ b/arch/arm/lib/delay-loop.S @@ -9,11 +9,11 @@ */ #include <linux/linkage.h> #include <asm/assembler.h> -#include <asm/param.h> +#include <asm/delay.h> .text .LC0: .word loops_per_jiffy -.LC1: .word (2199023*HZ)>>11 +.LC1: .word UDELAY_MULT /* * r0 <= 2000 @@ -21,10 +21,10 @@ * HZ <= 1000 */ -ENTRY(__udelay) +ENTRY(__loop_udelay) ldr r2, .LC1 mul r0, r2, r0 -ENTRY(__const_udelay) @ 0 <= r0 <= 0x7fffff06 +ENTRY(__loop_const_udelay) @ 0 <= r0 <= 0x7fffff06 mov r1, #-1 ldr r2, .LC0 ldr r2, [r2] @ max = 0x01ffffff @@ -39,12 +39,10 @@ ENTRY(__const_udelay) @ 0 <= r0 <= 0x7fffff06 /* * loops = r0 * HZ * loops_per_jiffy / 1000000 - * - * Oh, if only we had a cycle counter... */ @ Delay routine -ENTRY(__delay) +ENTRY(__loop_delay) subs r0, r0, #1 #if 0 movls pc, lr @@ -62,8 +60,8 @@ ENTRY(__delay) movls pc, lr subs r0, r0, #1 #endif - bhi __delay + bhi __loop_delay mov pc, lr -ENDPROC(__udelay) -ENDPROC(__const_udelay) -ENDPROC(__delay) +ENDPROC(__loop_udelay) +ENDPROC(__loop_const_udelay) +ENDPROC(__loop_delay) 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 @@ +/* + * Delay loops based on the OpenRISC implementation. + * + * Copyright (C) 2012 ARM Limited + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + * Author: Will Deacon <will.deacon@arm.com> + */ + +#include <linux/delay.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/timex.h> + +/* + * Default to the loop-based delay implementation. + */ +struct arm_delay_ops arm_delay_ops = { + .delay = __loop_delay, + .const_udelay = __loop_const_udelay, + .udelay = __loop_udelay, +}; + +#ifdef ARCH_HAS_READ_CURRENT_TIMER +static void __timer_delay(unsigned long cycles) +{ + cycles_t start = get_cycles(); + + while ((get_cycles() - start) < cycles) + cpu_relax(); +} + +static void __timer_const_udelay(unsigned long xloops) +{ + unsigned long long loops = xloops; + loops *= loops_per_jiffy; + __timer_delay(loops >> UDELAY_SHIFT); +} + +static void __timer_udelay(unsigned long usecs) +{ + __timer_const_udelay(usecs * UDELAY_MULT); +} + +void __init init_current_timer_delay(unsigned long freq) +{ + pr_info("Switching to timer-based delay loop\n"); + lpj_fine = freq / HZ; + arm_delay_ops.delay = __timer_delay; + arm_delay_ops.const_udelay = __timer_const_udelay; + arm_delay_ops.udelay = __timer_udelay; +} + +unsigned long __cpuinit calibrate_delay_is_known(void) +{ + return lpj_fine; +} +#endif diff --git a/arch/arm/mach-sa1100/sleep.S b/arch/arm/mach-sa1100/sleep.S index 30cc6721665b..85863741ef8b 100644 --- a/arch/arm/mach-sa1100/sleep.S +++ b/arch/arm/mach-sa1100/sleep.S @@ -38,9 +38,9 @@ ENTRY(sa1100_finish_suspend) orr r4, r4, #MDREFR_K1DB2 ldr r5, =PPCR - @ Pre-load __udelay into the I-cache + @ Pre-load __loop_udelay into the I-cache mov r0, #1 - bl __udelay + bl __loop_udelay mov r0, r0 @ The following must all exist in a single cache line to @@ -53,11 +53,11 @@ ENTRY(sa1100_finish_suspend) @ delay 90us and set CPU PLL to lowest speed @ fixes resume problem on high speed SA1110 mov r0, #90 - bl __udelay + bl __loop_udelay mov r1, #0 str r1, [r5] mov r0, #90 - bl __udelay + bl __loop_udelay /* * SA1110 SDRAM controller workaround. register values: |
