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linux/arch/arm/mm/pabort-v6.S

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ARM: 5727/1: Pass IFSR register to do_PrefetchAbort() Instruction fault status register, IFSR, was introduced on ARMv6 to provide status information about the last insturction fault. It needed for proper prefetch abort handling. Now we have three prefetch abort model: * legacy - for CPUs before ARMv6. They doesn't provide neither IFSR nor IFAR. We simulate IFSR with section translation fault status for them to generalize code; * ARMv6 - provides IFSR, but not IFAR; * ARMv7 - provides both IFSR and IFAR. Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2009-09-25 20:39:47 +08:00
#include <linux/linkage.h>
#include <asm/assembler.h>
/*
* Function: v6_pabort
*
ARM: entry: prefetch abort helper: pass aborted pc in r4 rather than r0 This avoids unnecessary instructions for CPUs which implement the IFAR (instruction fault address register). Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-06-26 02:25:02 +08:00
* Params : r4 = address of aborted instruction
ARM: 5727/1: Pass IFSR register to do_PrefetchAbort() Instruction fault status register, IFSR, was introduced on ARMv6 to provide status information about the last insturction fault. It needed for proper prefetch abort handling. Now we have three prefetch abort model: * legacy - for CPUs before ARMv6. They doesn't provide neither IFSR nor IFAR. We simulate IFSR with section translation fault status for them to generalize code; * ARMv6 - provides IFSR, but not IFAR; * ARMv7 - provides both IFSR and IFAR. Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2009-09-25 20:39:47 +08:00
*
* Returns : r0 = address of abort
* : r1 = IFSR
*
* Purpose : obtain information about current prefetch abort.
*/
.align 5
ENTRY(v6_pabort)
ARM: entry: prefetch abort helper: pass aborted pc in r4 rather than r0 This avoids unnecessary instructions for CPUs which implement the IFAR (instruction fault address register). Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-06-26 02:25:02 +08:00
mov r0, r4
ARM: 5727/1: Pass IFSR register to do_PrefetchAbort() Instruction fault status register, IFSR, was introduced on ARMv6 to provide status information about the last insturction fault. It needed for proper prefetch abort handling. Now we have three prefetch abort model: * legacy - for CPUs before ARMv6. They doesn't provide neither IFSR nor IFAR. We simulate IFSR with section translation fault status for them to generalize code; * ARMv6 - provides IFSR, but not IFAR; * ARMv7 - provides both IFSR and IFAR. Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2009-09-25 20:39:47 +08:00
mrc p15, 0, r1, c5, c0, 1 @ get IFSR
mov pc, lr
ENDPROC(v6_pabort)