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authorRussell King <rmk+kernel@arm.linux.org.uk>2011-01-16 20:59:44 +0300
committerRussell King <rmk+kernel@arm.linux.org.uk>2011-02-03 00:21:53 +0300
commita16ede35a2659170c855c5d267776666c0630f1f (patch)
tree67773b1c9aac890cd5838a6d58983f2d8643a1ba /arch/arm/lib/bitops.h
parente5310f611d17ed4e92e0d4e46fd9f6fb40e66df3 (diff)
downloadlinux-a16ede35a2659170c855c5d267776666c0630f1f.tar.xz
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>
Diffstat (limited to 'arch/arm/lib/bitops.h')
-rw-r--r--arch/arm/lib/bitops.h8
1 files changed, 8 insertions, 0 deletions
diff --git a/arch/arm/lib/bitops.h b/arch/arm/lib/bitops.h
index d42252918bfb..bd00551fb797 100644
--- a/arch/arm/lib/bitops.h
+++ b/arch/arm/lib/bitops.h
@@ -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