diff options
| author | Will Deacon <will.deacon@arm.com> | 2013-07-15 14:26:19 +0100 |
|---|---|---|
| committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2013-07-22 14:29:09 +0100 |
| commit | bf3f0f332f76a85ff3a0b393aaded5a8533769c0 (patch) | |
| tree | c2af37fb279885a29863ec1da7980f16976e8f21 /arch/arm/mm/proc-v7.S | |
| parent | b6992fa9a74862c5addb62cde1657c7479615d86 (diff) | |
ARM: 7784/1: mm: ensure SMP alternates assemble to exactly 4 bytes with Thumb-2
Commit ae8a8b9553bd ("ARM: 7691/1: mm: kill unused TLB_CAN_READ_FROM_L1_CACHE
and use ALT_SMP instead") added early function returns for page table
cache flushing operations on ARMv7 SMP CPUs.
Unfortunately, when targetting Thumb-2, these `mov pc, lr' sequences
assemble to 2 bytes which can lead to corruption of the instruction
stream after code patching.
This patch fixes the alternates to use wide (32-bit) instructions for
Thumb-2, therefore ensuring that the patching code works correctly.
Cc: <stable@vger.kernel.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/mm/proc-v7.S')
| -rw-r--r-- | arch/arm/mm/proc-v7.S | 11 |
1 files changed, 6 insertions, 5 deletions
diff --git a/arch/arm/mm/proc-v7.S b/arch/arm/mm/proc-v7.S index 5c6d5a3050ea..73398bcf9bd8 100644 --- a/arch/arm/mm/proc-v7.S +++ b/arch/arm/mm/proc-v7.S @@ -75,13 +75,14 @@ ENTRY(cpu_v7_do_idle) ENDPROC(cpu_v7_do_idle) ENTRY(cpu_v7_dcache_clean_area) - ALT_SMP(mov pc, lr) @ MP extensions imply L1 PTW - ALT_UP(W(nop)) - dcache_line_size r2, r3 -1: mcr p15, 0, r0, c7, c10, 1 @ clean D entry + ALT_SMP(W(nop)) @ MP extensions imply L1 PTW + ALT_UP_B(1f) + mov pc, lr +1: dcache_line_size r2, r3 +2: mcr p15, 0, r0, c7, c10, 1 @ clean D entry add r0, r0, r2 subs r1, r1, r2 - bhi 1b + bhi 2b dsb mov pc, lr ENDPROC(cpu_v7_dcache_clean_area) |