ARM: bitops: ensure set/clear/change bitops take a word-aligned pointer

Add additional instructions to our assembly bitops functions to ensure
that they only operate on word-aligned pointers.  This will be necessary
when we switch these operations to use the word-based exclusive
operations.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This commit is contained in:
Russell King 2011-01-16 17:59:44 +00:00
parent e5310f611d
commit a16ede35a2
1 changed files with 8 additions and 0 deletions

View File

@ -1,6 +1,8 @@
#if __LINUX_ARM_ARCH__ >= 6 && defined(CONFIG_CPU_32v6K)
.macro bitop, instr
ands ip, r1, #3
strneb r1, [ip] @ assert word-aligned
mov r2, #1
and r3, r0, #7 @ Get bit offset
add r1, r1, r0, lsr #3 @ Get byte offset
@ -14,6 +16,8 @@
.endm
.macro testop, instr, store
ands ip, r1, #3
strneb r1, [ip] @ assert word-aligned
and r3, r0, #7 @ Get bit offset
mov r2, #1
add r1, r1, r0, lsr #3 @ Get byte offset
@ -32,6 +36,8 @@
.endm
#else
.macro bitop, instr
ands ip, r1, #3
strneb r1, [ip] @ assert word-aligned
and r2, r0, #7
mov r3, #1
mov r3, r3, lsl r2
@ -52,6 +58,8 @@
* to avoid dirtying the data cache.
*/
.macro testop, instr, store
ands ip, r1, #3
strneb r1, [ip] @ assert word-aligned
add r1, r1, r0, lsr #3
and r3, r0, #7
mov r0, #1