From 8c56cc8be5b38e3684eba96dc9b3f7ca7e495755 Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Fri, 6 Jul 2012 15:45:39 +0100 Subject: ARM: 7449/1: use generic strnlen_user and strncpy_from_user functions This patch implements the word-at-a-time interface for ARM using the same algorithm as x86. We use the fls macro from ARMv5 onwards, where we have a clz instruction available which saves us a mov instruction when targetting Thumb-2. For older CPUs, we use the magic 0x0ff0001 constant. Big-endian configurations make use of the implementation from asm-generic. With this implemented, we can replace our byte-at-a-time strnlen_user and strncpy_from_user functions with the optimised generic versions. Reviewed-by: Nicolas Pitre Signed-off-by: Will Deacon Signed-off-by: Russell King --- arch/arm/lib/Makefile | 1 - arch/arm/lib/strncpy_from_user.S | 43 ---------------------------------------- arch/arm/lib/strnlen_user.S | 40 ------------------------------------- 3 files changed, 84 deletions(-) delete mode 100644 arch/arm/lib/strncpy_from_user.S delete mode 100644 arch/arm/lib/strnlen_user.S (limited to 'arch/arm/lib') diff --git a/arch/arm/lib/Makefile b/arch/arm/lib/Makefile index 992769ae259..d5060dab6e5 100644 --- a/arch/arm/lib/Makefile +++ b/arch/arm/lib/Makefile @@ -8,7 +8,6 @@ lib-y := backtrace.o changebit.o csumipv6.o csumpartial.o \ csumpartialcopy.o csumpartialcopyuser.o clearbit.o \ delay.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 \ testchangebit.o testclearbit.o testsetbit.o \ ashldi3.o ashrdi3.o lshrdi3.o muldi3.o \ diff --git a/arch/arm/lib/strncpy_from_user.S b/arch/arm/lib/strncpy_from_user.S deleted file mode 100644 index f202d7bd164..00000000000 --- a/arch/arm/lib/strncpy_from_user.S +++ /dev/null @@ -1,43 +0,0 @@ -/* - * linux/arch/arm/lib/strncpy_from_user.S - * - * Copyright (C) 1995-2000 Russell King - * - * 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. - */ -#include -#include -#include - - .text - .align 5 - -/* - * Copy a string from user space to kernel space. - * r0 = dst, r1 = src, r2 = byte length - * returns the number of characters copied (strlen of copied string), - * -EFAULT on exception, or "len" if we fill the whole buffer - */ -ENTRY(__strncpy_from_user) - mov ip, r1 -1: subs r2, r2, #1 - ldrusr r3, r1, 1, pl - bmi 2f - strb r3, [r0], #1 - teq r3, #0 - bne 1b - sub r1, r1, #1 @ take NUL character out of count -2: sub r0, r1, ip - mov pc, lr -ENDPROC(__strncpy_from_user) - - .pushsection .fixup,"ax" - .align 0 -9001: mov r3, #0 - strb r3, [r0, #0] @ null terminate - mov r0, #-EFAULT - mov pc, lr - .popsection - diff --git a/arch/arm/lib/strnlen_user.S b/arch/arm/lib/strnlen_user.S deleted file mode 100644 index 0ecbb459c4f..00000000000 --- a/arch/arm/lib/strnlen_user.S +++ /dev/null @@ -1,40 +0,0 @@ -/* - * linux/arch/arm/lib/strnlen_user.S - * - * Copyright (C) 1995-2000 Russell King - * - * 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. - */ -#include -#include -#include - - .text - .align 5 - -/* Prototype: unsigned long __strnlen_user(const char *str, long n) - * Purpose : get length of a string in user memory - * Params : str - address of string in user memory - * Returns : length of string *including terminator* - * or zero on exception, or n + 1 if too long - */ -ENTRY(__strnlen_user) - mov r2, r0 -1: - ldrusr r3, r0, 1 - teq r3, #0 - beq 2f - subs r1, r1, #1 - bne 1b - add r0, r0, #1 -2: sub r0, r0, r2 - mov pc, lr -ENDPROC(__strnlen_user) - - .pushsection .fixup,"ax" - .align 0 -9001: mov r0, #0 - mov pc, lr - .popsection -- cgit v1.2.3-18-g5258 From d0a533b18235d36206b9b422efadb7cee444dfdb Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Fri, 6 Jul 2012 15:47:17 +0100 Subject: ARM: 7452/1: delay: allow timer-based delay implementation to be selected This patch allows a timer-based delay implementation to be selected by switching the delay routines over to use get_cycles, which is implemented in terms of read_current_timer. This further allows us to skip the loop calibration and have a consistent delay function in the face of core frequency scaling. To avoid the pain of dealing with memory-mapped counters, this implementation uses the co-processor interface to the architected timers when they are available. The previous loop-based implementation is kept around for CPUs without the architected timers and we retain both the maximum delay (2ms) and the corresponding conversion factors for determining the number of loops required for a given interval. Since the indirection of the timer routines will only work when called from C, the sa1100 sleep routines are modified to branch to the loop-based delay functions directly. Tested-by: Shinya Kuribayashi Reviewed-by: Stephen Boyd Signed-off-by: Will Deacon Signed-off-by: Russell King --- arch/arm/lib/Makefile | 2 +- arch/arm/lib/delay-loop.S | 67 ++++++++++++++++++++++++++++++++++++++++++++ arch/arm/lib/delay.S | 69 --------------------------------------------- arch/arm/lib/delay.c | 71 +++++++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 139 insertions(+), 70 deletions(-) create mode 100644 arch/arm/lib/delay-loop.S delete mode 100644 arch/arm/lib/delay.S create mode 100644 arch/arm/lib/delay.c (limited to 'arch/arm/lib') diff --git a/arch/arm/lib/Makefile b/arch/arm/lib/Makefile index 992769ae259..b621114644f 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-loop.S b/arch/arm/lib/delay-loop.S new file mode 100644 index 00000000000..36b668d8e12 --- /dev/null +++ b/arch/arm/lib/delay-loop.S @@ -0,0 +1,67 @@ +/* + * linux/arch/arm/lib/delay.S + * + * Copyright (C) 1995, 1996 Russell King + * + * 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. + */ +#include +#include +#include + .text + +.LC0: .word loops_per_jiffy +.LC1: .word UDELAY_MULT + +/* + * r0 <= 2000 + * lpj <= 0x01ffffff (max. 3355 bogomips) + * HZ <= 1000 + */ + +ENTRY(__loop_udelay) + ldr r2, .LC1 + mul r0, r2, r0 +ENTRY(__loop_const_udelay) @ 0 <= r0 <= 0x7fffff06 + mov r1, #-1 + ldr r2, .LC0 + ldr r2, [r2] @ max = 0x01ffffff + add r0, r0, r1, lsr #32-14 + mov r0, r0, lsr #14 @ max = 0x0001ffff + add r2, r2, r1, lsr #32-10 + mov r2, r2, lsr #10 @ max = 0x00007fff + mul r0, r2, r0 @ max = 2^32-1 + add r0, r0, r1, lsr #32-6 + movs r0, r0, lsr #6 + moveq pc, lr + +/* + * loops = r0 * HZ * loops_per_jiffy / 1000000 + */ + +@ Delay routine +ENTRY(__loop_delay) + subs r0, r0, #1 +#if 0 + movls pc, lr + subs r0, r0, #1 + movls pc, lr + subs r0, r0, #1 + movls pc, lr + subs r0, r0, #1 + movls pc, lr + subs r0, r0, #1 + movls pc, lr + subs r0, r0, #1 + movls pc, lr + subs r0, r0, #1 + movls pc, lr + subs r0, r0, #1 +#endif + bhi __loop_delay + mov pc, lr +ENDPROC(__loop_udelay) +ENDPROC(__loop_const_udelay) +ENDPROC(__loop_delay) diff --git a/arch/arm/lib/delay.S b/arch/arm/lib/delay.S deleted file mode 100644 index 3c9a05c8d20..00000000000 --- a/arch/arm/lib/delay.S +++ /dev/null @@ -1,69 +0,0 @@ -/* - * linux/arch/arm/lib/delay.S - * - * Copyright (C) 1995, 1996 Russell King - * - * 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. - */ -#include -#include -#include - .text - -.LC0: .word loops_per_jiffy -.LC1: .word (2199023*HZ)>>11 - -/* - * r0 <= 2000 - * lpj <= 0x01ffffff (max. 3355 bogomips) - * HZ <= 1000 - */ - -ENTRY(__udelay) - ldr r2, .LC1 - mul r0, r2, r0 -ENTRY(__const_udelay) @ 0 <= r0 <= 0x7fffff06 - mov r1, #-1 - ldr r2, .LC0 - ldr r2, [r2] @ max = 0x01ffffff - add r0, r0, r1, lsr #32-14 - mov r0, r0, lsr #14 @ max = 0x0001ffff - add r2, r2, r1, lsr #32-10 - mov r2, r2, lsr #10 @ max = 0x00007fff - mul r0, r2, r0 @ max = 2^32-1 - add r0, r0, r1, lsr #32-6 - movs r0, r0, lsr #6 - moveq pc, lr - -/* - * loops = r0 * HZ * loops_per_jiffy / 1000000 - * - * Oh, if only we had a cycle counter... - */ - -@ Delay routine -ENTRY(__delay) - subs r0, r0, #1 -#if 0 - movls pc, lr - subs r0, r0, #1 - movls pc, lr - subs r0, r0, #1 - movls pc, lr - subs r0, r0, #1 - movls pc, lr - subs r0, r0, #1 - movls pc, lr - subs r0, r0, #1 - movls pc, lr - subs r0, r0, #1 - movls pc, lr - subs r0, r0, #1 -#endif - bhi __delay - mov pc, lr -ENDPROC(__udelay) -ENDPROC(__const_udelay) -ENDPROC(__delay) diff --git a/arch/arm/lib/delay.c b/arch/arm/lib/delay.c new file mode 100644 index 00000000000..d6dacc69254 --- /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 + */ + +#include +#include +#include +#include +#include + +/* + * 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 -- cgit v1.2.3-18-g5258