26584853a4
Starting with ARMv6, the CPUs support the BE-8 variant of big-endian (byte-invariant). This patch adds the core support: - setting of the BE-8 mode via the CPSR.E register for both kernel and user threads - big-endian page table walking - REV used to rotate instructions read from memory during fault processing as they are still little-endian format - Kconfig and Makefile support for BE-8. The --be8 option must be passed to the final linking stage to convert the instructions to little-endian Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
49 lines
1.3 KiB
ArmAsm
49 lines
1.3 KiB
ArmAsm
#include <linux/linkage.h>
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#include <asm/assembler.h>
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#include "abort-macro.S"
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/*
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* Function: v6_early_abort
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*
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* Params : r2 = address of aborted instruction
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* : r3 = saved SPSR
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*
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* Returns : r0 = address of abort
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* : r1 = FSR, bit 11 = write
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* : r2-r8 = corrupted
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* : r9 = preserved
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* : sp = pointer to registers
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*
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* Purpose : obtain information about current aborted instruction.
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* Note: we read user space. This means we might cause a data
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* abort here if the I-TLB and D-TLB aren't seeing the same
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* picture. Unfortunately, this does happen. We live with it.
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*/
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.align 5
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ENTRY(v6_early_abort)
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#ifdef CONFIG_CPU_32v6K
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clrex
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#else
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sub r1, sp, #4 @ Get unused stack location
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strex r0, r1, [r1] @ Clear the exclusive monitor
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#endif
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mrc p15, 0, r1, c5, c0, 0 @ get FSR
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mrc p15, 0, r0, c6, c0, 0 @ get FAR
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/*
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* Faulty SWP instruction on 1136 doesn't set bit 11 in DFSR (erratum 326103).
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* The test below covers all the write situations, including Java bytecodes
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*/
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bic r1, r1, #1 << 11 @ clear bit 11 of FSR
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tst r3, #PSR_J_BIT @ Java?
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movne pc, lr
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do_thumb_abort
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ldreq r3, [r2] @ read aborted ARM instruction
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#ifdef CONFIG_CPU_ENDIAN_BE8
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reveq r3, r3
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#endif
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do_ldrd_abort
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tst r3, #1 << 20 @ L = 0 -> write
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orreq r1, r1, #1 << 11 @ yes.
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mov pc, lr
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