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linux/arch/arm/mm/pabort-legacy.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: legacy_pabort
*
ARM: entry: prefetch abort: tail-call the main prefetch abort handler Tail-call the main C prefetch abort handler code from the per-CPU helper code. Also note that the helper function becomes ABI compliant in terms of the registers preserved. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-06-26 19:37:35 +08:00
* Params : r2 = pt_regs
* : r4 = address of aborted instruction
* : r5 = psr for parent context
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
*
ARM: entry: prefetch abort: tail-call the main prefetch abort handler Tail-call the main C prefetch abort handler code from the per-CPU helper code. Also note that the helper function becomes ABI compliant in terms of the registers preserved. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-06-26 19:37:35 +08:00
* Returns : r4 - r11, r13 preserved
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
*
* Purpose : obtain information about current prefetch abort.
*/
.align 5
ENTRY(legacy_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
mov r1, #5
ARM: entry: prefetch abort: tail-call the main prefetch abort handler Tail-call the main C prefetch abort handler code from the per-CPU helper code. Also note that the helper function becomes ABI compliant in terms of the registers preserved. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-06-26 19:37:35 +08:00
b do_PrefetchAbort
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
ENDPROC(legacy_pabort)