root/arch/arm/mm/abort-ev5t.S

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #include <linux/linkage.h>
   3 #include <asm/assembler.h>
   4 #include "abort-macro.S"
   5 /*
   6  * Function: v5t_early_abort
   7  *
   8  * Params  : r2 = pt_regs
   9  *         : r4 = aborted context pc
  10  *         : r5 = aborted context psr
  11  *
  12  * Returns : r4 - r11, r13 preserved
  13  *
  14  * Purpose : obtain information about current aborted instruction.
  15  * Note: we read user space.  This means we might cause a data
  16  * abort here if the I-TLB and D-TLB aren't seeing the same
  17  * picture.  Unfortunately, this does happen.  We live with it.
  18  */
  19         .align  5
  20 ENTRY(v5t_early_abort)
  21         mrc     p15, 0, r1, c5, c0, 0           @ get FSR
  22         mrc     p15, 0, r0, c6, c0, 0           @ get FAR
  23         do_thumb_abort fsr=r1, pc=r4, psr=r5, tmp=r3
  24         ldreq   r3, [r4]                        @ read aborted ARM instruction
  25         uaccess_disable ip                      @ disable user access
  26         bic     r1, r1, #1 << 11                @ clear bits 11 of FSR
  27         teq_ldrd tmp=ip, insn=r3                @ insn was LDRD?
  28         beq     do_DataAbort                    @ yes
  29         tst     r3, #1 << 20                    @ check write
  30         orreq   r1, r1, #1 << 11
  31         b       do_DataAbort