arch/arm/mm/abort-ev4.S

   1 #include <linux/linkage.h>
   2 #include <asm/assembler.h>
   3 /*
   4  * Function: v4_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  * Note: we read user space.  This means we might cause a data
  14  * abort here if the I-TLB and D-TLB aren't seeing the same
  15  * picture.  Unfortunately, this does happen.  We live with it.
  16  */
  17         .align  5
  18 ENTRY(v4_early_abort)
  19         mrc     p15, 0, r1, c5, c0, 0           @ get FSR
  20         mrc     p15, 0, r0, c6, c0, 0           @ get FAR
  21         ldr     r3, [r4]                        @ read aborted ARM instruction
  22         uaccess_disable ip                      @ disable userspace access
  23         bic     r1, r1, #1 << 11 | 1 << 10      @ clear bits 11 and 10 of FSR
  24         tst     r3, #1 << 20                    @ L = 1 -> write?
  25         orreq   r1, r1, #1 << 11                @ yes.
  26         b       do_DataAbort