kernel_optimize_test/arch/arm/mm/abort-ev6.S
Catalin Marinas fe68e68f6a [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>
2009-04-01 22:15:57 +01:00

46 lines
1.2 KiB
ArmAsm

#include <linux/linkage.h>
#include <asm/assembler.h>
#include "abort-macro.S"
/*
* Function: v6_early_abort
*
* Params : r2 = address of aborted instruction
* : r3 = saved SPSR
*
* Returns : r0 = address of abort
* : r1 = FSR, bit 11 = write
* : r2-r8 = corrupted
* : r9 = preserved
* : sp = pointer to registers
*
* Purpose : obtain information about current aborted instruction.
* Note: we read user space. This means we might cause a data
* abort here if the I-TLB and D-TLB aren't seeing the same
* picture. Unfortunately, this does happen. We live with it.
*/
.align 5
ENTRY(v6_early_abort)
#ifdef CONFIG_CPU_32v6K
clrex
#else
sub r1, sp, #4 @ Get unused stack location
strex r0, r1, [r1] @ Clear the exclusive monitor
#endif
mrc p15, 0, r1, c5, c0, 0 @ get FSR
mrc p15, 0, r0, c6, c0, 0 @ get FAR
/*
* Faulty SWP instruction on 1136 doesn't set bit 11 in DFSR (erratum 326103).
* The test below covers all the write situations, including Java bytecodes
*/
bic r1, r1, #1 << 11 @ clear bit 11 of FSR
tst r3, #PSR_J_BIT @ Java?
movne pc, lr
do_thumb_abort
ldreq r3, [r2] @ read aborted ARM instruction
do_ldrd_abort
tst r3, #1 << 20 @ L = 0 -> write
orreq r1, r1, #1 << 11 @ yes.
mov pc, lr