arm/mm/abort-ev5t.S

0001 /* SPDX-License-Identifier: GPL-2.0 */
0002 #include <linux/linkage.h>
0003 #include <asm/assembler.h>
0004 #include "abort-macro.S"
0005 /*
0006  * Function: v5t_early_abort
0007  *
0008  * Params  : r2 = pt_regs
0009  *     : r4 = aborted context pc
0010  *     : r5 = aborted context psr
0011  *
0012  * Returns : r4 - r11, r13 preserved
0013  *
0014  * Purpose : obtain information about current aborted instruction.
0015  * Note: we read user space.  This means we might cause a data
0016  * abort here if the I-TLB and D-TLB aren't seeing the same
0017  * picture.  Unfortunately, this does happen.  We live with it.
0018  */
0019     .align  5
0020 ENTRY(v5t_early_abort)
0021     mrc p15, 0, r1, c5, c0, 0       @ get FSR
0022     mrc p15, 0, r0, c6, c0, 0       @ get FAR
0023     do_thumb_abort fsr=r1, pc=r4, psr=r5, tmp=r3
0024     ldreq   r3, [r4]            @ read aborted ARM instruction
0025     uaccess_disable ip          @ disable user access
0026     bic r1, r1, #1 << 11        @ clear bits 11 of FSR
0027     teq_ldrd tmp=ip, insn=r3        @ insn was LDRD?
0028     beq do_DataAbort            @ yes
0029     tst r3, #1 << 20            @ check write
0030     orreq   r1, r1, #1 << 11
0031     b   do_DataAbort