[RFC PATCH 4/5] arm64: Replace our atomic bitops implementation with asm-generic
From: Will Deacon <hidden>
Date: 2018-02-15 17:56:01
Also in:
lkml
Subsystem:
arm64 port (aarch64 architecture), bitops api, the rest · Maintainers:
Catalin Marinas, Will Deacon, Yury Norov, Linus Torvalds
The asm-generic/bitops/atomic.h implementation is built around the atomic-fetch ops, which we implement efficiently for both LSE and LL/SC systems. Use that instead of our hand-rolled, out-of-line bitops.S. Signed-off-by: Will Deacon <redacted> --- arch/arm64/include/asm/bitops.h | 13 +------ arch/arm64/lib/Makefile | 2 +- arch/arm64/lib/bitops.S | 76 ----------------------------------------- 3 files changed, 2 insertions(+), 89 deletions(-) delete mode 100644 arch/arm64/lib/bitops.S
diff --git a/arch/arm64/include/asm/bitops.h b/arch/arm64/include/asm/bitops.h
index 9c19594ce7cb..817233fbf249 100644
--- a/arch/arm64/include/asm/bitops.h
+++ b/arch/arm64/include/asm/bitops.h@@ -17,22 +17,11 @@ #define __ASM_BITOPS_H #include <linux/compiler.h> -#include <asm/barrier.h> #ifndef _LINUX_BITOPS_H #error only <linux/bitops.h> can be included directly #endif -/* - * Little endian assembly atomic bitops. - */ -extern void set_bit(int nr, volatile unsigned long *p); -extern void clear_bit(int nr, volatile unsigned long *p); -extern void change_bit(int nr, volatile unsigned long *p); -extern int test_and_set_bit(int nr, volatile unsigned long *p); -extern int test_and_clear_bit(int nr, volatile unsigned long *p); -extern int test_and_change_bit(int nr, volatile unsigned long *p); - #include <asm-generic/bitops/builtin-__ffs.h> #include <asm-generic/bitops/builtin-ffs.h> #include <asm-generic/bitops/builtin-__fls.h>
@@ -44,8 +33,8 @@ extern int test_and_change_bit(int nr, volatile unsigned long *p); #include <asm-generic/bitops/sched.h> #include <asm-generic/bitops/hweight.h> -#include <asm-generic/bitops/lock.h> +#include <asm-generic/bitops/atomic.h> #include <asm-generic/bitops/non-atomic.h> #include <asm-generic/bitops/le.h>
diff --git a/arch/arm64/lib/Makefile b/arch/arm64/lib/Makefile
index 4e696f96451f..73095a04c0ad 100644
--- a/arch/arm64/lib/Makefile
+++ b/arch/arm64/lib/Makefile@@ -1,5 +1,5 @@ # SPDX-License-Identifier: GPL-2.0 -lib-y := bitops.o clear_user.o delay.o copy_from_user.o \ +lib-y := clear_user.o delay.o copy_from_user.o \ copy_to_user.o copy_in_user.o copy_page.o \ clear_page.o memchr.o memcpy.o memmove.o memset.o \ memcmp.o strcmp.o strncmp.o strlen.o strnlen.o \
diff --git a/arch/arm64/lib/bitops.S b/arch/arm64/lib/bitops.S
deleted file mode 100644
index 43ac736baa5b..000000000000
--- a/arch/arm64/lib/bitops.S
+++ /dev/null@@ -1,76 +0,0 @@ -/* - * Based on arch/arm/lib/bitops.h - * - * Copyright (C) 2013 ARM Ltd. - * - * 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, see <http://www.gnu.org/licenses/>. - */ - -#include <linux/linkage.h> -#include <asm/assembler.h> -#include <asm/lse.h> - -/* - * x0: bits 5:0 bit offset - * bits 31:6 word offset - * x1: address - */ - .macro bitop, name, llsc, lse -ENTRY( \name ) - and w3, w0, #63 // Get bit offset - eor w0, w0, w3 // Clear low bits - mov x2, #1 - add x1, x1, x0, lsr #3 // Get word offset -alt_lse " prfm pstl1strm, [x1]", "nop" - lsl x3, x2, x3 // Create mask - -alt_lse "1: ldxr x2, [x1]", "\lse x3, [x1]" -alt_lse " \llsc x2, x2, x3", "nop" -alt_lse " stxr w0, x2, [x1]", "nop" -alt_lse " cbnz w0, 1b", "nop" - - ret -ENDPROC(\name ) - .endm - - .macro testop, name, llsc, lse -ENTRY( \name ) - and w3, w0, #63 // Get bit offset - eor w0, w0, w3 // Clear low bits - mov x2, #1 - add x1, x1, x0, lsr #3 // Get word offset -alt_lse " prfm pstl1strm, [x1]", "nop" - lsl x4, x2, x3 // Create mask - -alt_lse "1: ldxr x2, [x1]", "\lse x4, x2, [x1]" - lsr x0, x2, x3 -alt_lse " \llsc x2, x2, x4", "nop" -alt_lse " stlxr w5, x2, [x1]", "nop" -alt_lse " cbnz w5, 1b", "nop" -alt_lse " dmb ish", "nop" - - and x0, x0, #1 - ret -ENDPROC(\name ) - .endm - -/* - * Atomic bit operations. - */ - bitop change_bit, eor, steor - bitop clear_bit, bic, stclr - bitop set_bit, orr, stset - - testop test_and_change_bit, eor, ldeoral - testop test_and_clear_bit, bic, ldclral - testop test_and_set_bit, orr, ldsetal
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2.1.4