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 #include <linux/init.h>
  12 #include <linux/linkage.h>
  13 #include <asm/thread_info.h>
  14 #include <asm/vfpmacros.h>
  15 #include <asm/assembler.h>
  16 #include <asm/asm-offsets.h>
  17
  18 @ VFP entry point.
  19 @
  20 @  r0  = instruction opcode (32-bit ARM or two 16-bit Thumb)
  21 @  r2  = PC value to resume execution after successful emulation
  22 @  r9  = normal "successful" return address
  23 @  r10 = this threads thread_info structure
  24 @  lr  = unrecognised instruction return address
  25 @  IRQs enabled.
  26 @
  27 ENTRY(do_vfp)
  28         inc_preempt_count r10, r4
  29         ldr     r4, .LCvfp
  30         ldr     r11, [r10, #TI_CPU]     @ CPU number
  31         add     r10, r10, #TI_VFPSTATE  @ r10 = workspace
  32         ldr     pc, [r4]                @ call VFP entry point
  33 ENDPROC(do_vfp)
  34
  35 ENTRY(vfp_null_entry)
  36         dec_preempt_count_ti r10, r4
  37         ret     lr
  38 ENDPROC(vfp_null_entry)
  39
  40         .align  2
  41 .LCvfp:
  42         .word   vfp_vector
  43
  44 @ This code is called if the VFP does not exist. It needs to flag the
  45 @ failure to the VFP initialisation code.
  46
  47         __INIT
  48 ENTRY(vfp_testing_entry)
  49         dec_preempt_count_ti r10, r4
  50         ldr     r0, VFP_arch_address
  51         str     r0, [r0]                @ set to non-zero value
  52         ret     r9                      @ we have handled the fault
  53 ENDPROC(vfp_testing_entry)
  54
  55         .align  2
  56 VFP_arch_address:
  57         .word   VFP_arch
  58
  59         __FINIT