Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel os linux

[ARM] 5439/1: Do not clear bit 10 of DFSR during abort handling on ARMv6

Because of an ARM1136 erratum (326103), the current v6_early_abort
function needs to set the correct FSR[11] value which determines whether
the data abort was caused by a read or write. For legacy reasons (bit 10
not handled by software), bit 10 was also cleared masking out imprecise
aborts on ARMv6 CPUs. This patch removes the clearing of bit 10 of FSR.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

authored by

Catalin Marinas and committed by
Russell King
fe68e68f 01a24d2b

+2 -2
+2 -2
arch/arm/mm/abort-ev6.S
··· 29 29 mrc p15, 0, r1, c5, c0, 0 @ get FSR 30 30 mrc p15, 0, r0, c6, c0, 0 @ get FAR 31 31 /* 32 - * Faulty SWP instruction on 1136 doesn't set bit 11 in DFSR. 32 + * Faulty SWP instruction on 1136 doesn't set bit 11 in DFSR (erratum 326103). 33 33 * The test below covers all the write situations, including Java bytecodes 34 34 */ 35 - bic r1, r1, #1 << 11 | 1 << 10 @ clear bits 11 and 10 of FSR 35 + bic r1, r1, #1 << 11 @ clear bit 11 of FSR 36 36 tst r3, #PSR_J_BIT @ Java? 37 37 movne pc, lr 38 38 do_thumb_abort