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authorWill Deacon <will.deacon@arm.com>2018-06-19 14:53:13 +0200
committerIngo Molnar <mingo@kernel.org>2018-06-21 12:52:12 +0200
commit7c8fc35dfc32dfa97d8a1dc25dbd064cf83936db (patch)
tree0ba317c82a0968d5db1441ba8e82ed1ddafe94f1 /arch/arm64/lib
parentlocking/atomics, asm-generic/bitops/lock.h: Rewrite using atomic_fetch_*() (diff)
downloadlinux-7c8fc35dfc32dfa97d8a1dc25dbd064cf83936db.tar.xz
linux-7c8fc35dfc32dfa97d8a1dc25dbd064cf83936db.zip
locking/atomics/arm64: Replace our atomic/lock bitop implementations with asm-generic
The <asm-generic/bitops/{atomic,lock}.h> implementations are 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 <will.deacon@arm.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-arm-kernel@lists.infradead.org Cc: yamada.masahiro@socionext.com Link: https://lore.kernel.org/lkml/1529412794-17720-9-git-send-email-will.deacon@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/arm64/lib')
-rw-r--r--arch/arm64/lib/Makefile2
-rw-r--r--arch/arm64/lib/bitops.S76
2 files changed, 1 insertions, 77 deletions
diff --git a/arch/arm64/lib/Makefile b/arch/arm64/lib/Makefile
index 137710f4dac3..68755fd70dcf 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