arch/arm/vfp/entry.S

   1 /*
   2  *  linux/arch/arm/vfp/entry.S
   3  *
   4  *  Copyright (C) 2004 ARM Limited.
   5  *  Written by Deep Blue Solutions Limited.
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  *
  11  * Basic entry code, called from the kernel's undefined instruction trap.
  12  *  r0  = faulted instruction
  13  *  r5  = faulted PC+4
  14  *  r9  = successful return
  15  *  r10 = thread_info structure
  16  *  lr  = failure return
  17  */
  18 #include <linux/linkage.h>
  19 #include <linux/init.h>
  20 #include <asm/asm-offsets.h>
  21 #include <asm/assembler.h>
  22 #include <asm/vfpmacros.h>
  23
  24         .globl  do_vfp
  25 do_vfp:
  26         enable_irq
  27         ldr     r4, .LCvfp
  28         ldr     r11, [r10, #TI_CPU]     @ CPU number
  29         add     r10, r10, #TI_VFPSTATE  @ r10 = workspace
  30         ldr     pc, [r4]                @ call VFP entry point
  31
  32 ENTRY(vfp_null_entry)
  33         mov     pc, lr
  34 ENDPROC(vfp_null_entry)
  35
  36 .LCvfp:
  37         .word   vfp_vector
  38
  39 @ This code is called if the VFP does not exist. It needs to flag the
  40 @ failure to the VFP initialisation code.
  41
  42         __INIT
  43         .globl  vfp_testing_entry
  44 vfp_testing_entry:
  45         ldr     r0, VFP_arch_address
  46         str     r5, [r0]                @ known non-zero value
  47         mov     pc, r9                  @ we have handled the fault
  48
  49 VFP_arch_address:
  50         .word   VFP_arch
  51
  52         __FINIT