arch/arm/cpu/armv8/transition.S

   1 /* SPDX-License-Identifier: GPL-2.0+ */
   2 /*
   3  * (C) Copyright 2013
   4  * David Feng <fenghua@phytium.com.cn>
   5  */
   6
   7 #include <asm-offsets.h>
   8 #include <config.h>
   9 #include <linux/linkage.h>
  10 #include <asm/macro.h>
  11
  12 .pushsection .text.armv8_switch_to_el2, "ax"
  13 ENTRY(armv8_switch_to_el2)
  14         switch_el x6, 1f, 0f, 0f
  15 0:
  16         cmp x5, #ES_TO_AARCH64
  17         b.eq 2f
  18         /*
  19          * When loading 32-bit kernel, it will jump
  20          * to secure firmware again, and never return.
  21          */
  22         bl armv8_el2_to_aarch32
  23 2:
  24         /*
  25          * x4 is kernel entry point or switch_to_el1
  26          * if CONFIG_ARMV8_SWITCH_TO_EL1 is defined.
  27          * When running in EL2 now, jump to the
  28          * address saved in x4.
  29          */
  30         br x4
  31 1:      armv8_switch_to_el2_m x4, x5, x6
  32 ENDPROC(armv8_switch_to_el2)
  33 .popsection
  34
  35 .pushsection .text.armv8_switch_to_el1, "ax"
  36 ENTRY(armv8_switch_to_el1)
  37         switch_el x6, 0f, 1f, 0f
  38 0:
  39         /* x4 is kernel entry point. When running in EL1
  40          * now, jump to the address saved in x4.
  41          */
  42         br x4
  43 1:      armv8_switch_to_el1_m x4, x5, x6
  44 ENDPROC(armv8_switch_to_el1)
  45 .popsection
  46
  47 .pushsection .text.armv8_el2_to_aarch32, "ax"
  48 WEAK(armv8_el2_to_aarch32)
  49         ret
  50 ENDPROC(armv8_el2_to_aarch32)
  51 .popsection