2
0
mirror of https://github.com/edk2-porting/linux-next.git synced 2024-12-26 14:14:01 +08:00
linux-next/arch/arm64/lib/bitops.S
Catalin Marinas 420c158dcf arm64: Treat the bitops index argument as an 'int'
The bitops prototype use an 'int' as the bit index type but the asm
implementation assume it to be a 'long'. Since the compiler does not
guarantee zeroing the upper 32-bits in a register when used as 'int',
change the bitops implementation accordingly.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2013-05-08 10:33:17 +01:00

69 lines
1.6 KiB
ArmAsm

/*
* 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>
/*
* x0: bits 5:0 bit offset
* bits 31:6 word offset
* x1: address
*/
.macro bitop, name, instr
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
lsl x3, x2, x3 // Create mask
1: ldxr x2, [x1]
\instr x2, x2, x3
stxr w0, x2, [x1]
cbnz w0, 1b
ret
ENDPROC(\name )
.endm
.macro testop, name, instr
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
lsl x4, x2, x3 // Create mask
1: ldaxr x2, [x1]
lsr x0, x2, x3 // Save old value of bit
\instr x2, x2, x4 // toggle bit
stlxr w5, x2, [x1]
cbnz w5, 1b
and x0, x0, #1
3: ret
ENDPROC(\name )
.endm
/*
* Atomic bit operations.
*/
bitop change_bit, eor
bitop clear_bit, bic
bitop set_bit, orr
testop test_and_change_bit, eor
testop test_and_clear_bit, bic
testop test_and_set_bit, orr