arch/arm/mm/abort-ev7.S

   1 #include <linux/linkage.h>
   2 #include <asm/assembler.h>
   3 /*
   4  * Function: v7_early_abort
   5  *
   6  * Params  : r2 = pt_regs
   7  *         : r4 = aborted context pc
   8  *         : r5 = aborted context psr
   9  *
  10  * Returns : r4 - r11, r13 preserved
  11  *
  12  * Purpose : obtain information about current aborted instruction.
  13  */
  14         .align  5
  15 ENTRY(v7_early_abort)
  16         /*
  17          * The effect of data aborts on on the exclusive access monitor are
  18          * UNPREDICTABLE. Do a CLREX to clear the state
  19          */
  20         clrex
  21
  22         mrc     p15, 0, r1, c5, c0, 0           @ get FSR
  23         mrc     p15, 0, r0, c6, c0, 0           @ get FAR
  24
  25         /*
  26          * V6 code adjusts the returned DFSR.
  27          * New designs should not need to patch up faults.
  28          */
  29
  30 #if defined(CONFIG_VERIFY_PERMISSION_FAULT)
  31         /*
  32          * Detect erroneous permission failures and fix
  33          */
  34         ldr     r3, =0x40d                      @ On permission fault
  35         and     r3, r1, r3
  36         cmp     r3, #0x0d
  37         bne     do_DataAbort
  38
  39         mcr     p15, 0, r0, c7, c8, 0           @ Retranslate FAR
  40         isb
  41         mrc     p15, 0, ip, c7, c4, 0           @ Read the PAR
  42         and     r3, ip, #0x7b                   @ On translation fault
  43         cmp     r3, #0x0b
  44         bne     do_DataAbort
  45         bic     r1, r1, #0xf                    @ Fix up FSR FS[5:0]
  46         and     ip, ip, #0x7e
  47         orr     r1, r1, ip, LSR #1
  48 #endif
  49
  50         b       do_DataAbort
  51 ENDPROC(v7_early_abort)