ARM: bitops: ensure set/clear/change bitops take a word-aligned pointer (a16ede35) · Commits · 戴 / test

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>

arch/arm/lib/bitops.h

+8 −0

Original line number	Diff line number	Diff line

		#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

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