arm/mm/abort-ev4.S

0001 /* SPDX-License-Identifier: GPL-2.0 */
0002 #include <linux/linkage.h>
0003 #include <asm/assembler.h>
0004 /*
0005  * Function: v4_early_abort
0006  *
0007  * Params  : r2 = pt_regs
0008  *     : r4 = aborted context pc
0009  *     : r5 = aborted context psr
0010  *
0011  * Returns : r4 - r11, r13 preserved
0012  *
0013  * Purpose : obtain information about current aborted instruction.
0014  * Note: we read user space.  This means we might cause a data
0015  * abort here if the I-TLB and D-TLB aren't seeing the same
0016  * picture.  Unfortunately, this does happen.  We live with it.
0017  */
0018     .align  5
0019 ENTRY(v4_early_abort)
0020     mrc p15, 0, r1, c5, c0, 0       @ get FSR
0021     mrc p15, 0, r0, c6, c0, 0       @ get FAR
0022     ldr r3, [r4]            @ read aborted ARM instruction
0023     uaccess_disable ip          @ disable userspace access
0024     bic r1, r1, #1 << 11 | 1 << 10  @ clear bits 11 and 10 of FSR
0025     tst r3, #1 << 20            @ L = 1 -> write?
0026     orreq   r1, r1, #1 << 11        @ yes.
0027     b   do_DataAbort