root/arch/arm/mm/abort-ev7.S

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #include <linux/linkage.h>
   3 #include <asm/assembler.h>
   4 /*
   5  * Function: v7_early_abort
   6  *
   7  * Params  : r2 = pt_regs
   8  *         : r4 = aborted context pc
   9  *         : r5 = aborted context psr
  10  *
  11  * Returns : r4 - r11, r13 preserved
  12  *
  13  * Purpose : obtain information about current aborted instruction.
  14  */
  15         .align  5
  16 ENTRY(v7_early_abort)
  17         mrc     p15, 0, r1, c5, c0, 0           @ get FSR
  18         mrc     p15, 0, r0, c6, c0, 0           @ get FAR
  19         uaccess_disable ip                      @ disable userspace access
  20 
  21         /*
  22          * V6 code adjusts the returned DFSR.
  23          * New designs should not need to patch up faults.
  24          */
  25 
  26 #if defined(CONFIG_VERIFY_PERMISSION_FAULT)
  27         /*
  28          * Detect erroneous permission failures and fix
  29          */
  30         ldr     r3, =0x40d                      @ On permission fault
  31         and     r3, r1, r3
  32         cmp     r3, #0x0d
  33         bne     do_DataAbort
  34 
  35         mcr     p15, 0, r0, c7, c8, 0           @ Retranslate FAR
  36         isb
  37         mrc     p15, 0, ip, c7, c4, 0           @ Read the PAR
  38         and     r3, ip, #0x7b                   @ On translation fault
  39         cmp     r3, #0x0b
  40         bne     do_DataAbort
  41         bic     r1, r1, #0xf                    @ Fix up FSR FS[5:0]
  42         and     ip, ip, #0x7e
  43         orr     r1, r1, ip, LSR #1
  44 #endif
  45 
  46         b       do_DataAbort
  47 ENDPROC(v7_early_abort)