arch/arm/mach-exynos/sleep.S

   1 /*
   2  * Copyright (c) 2013 Samsung Electronics Co., Ltd.
   3  *              http://www.samsung.com
   4  *
   5  * Exynos low-level resume code
   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 as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  */
  17
  18 #include <linux/linkage.h>
  19
  20 #define CPU_MASK        0xff0ffff0
  21 #define CPU_CORTEX_A9   0x410fc090
  22
  23         /*
  24          * The following code is located into the .data section. This is to
  25          * allow l2x0_regs_phys to be accessed with a relative load while we
  26          * can't rely on any MMU translation. We could have put l2x0_regs_phys
  27          * in the .text section as well, but some setups might insist on it to
  28          * be truly read-only. (Reference from: arch/arm/kernel/sleep.S)
  29          */
  30         .data
  31         .align
  32
  33         /*
  34          * sleep magic, to allow the bootloader to check for an valid
  35          * image to resume to. Must be the first word before the
  36          * exynos_cpu_resume entry.
  37          */
  38
  39         .word   0x2bedf00d
  40
  41         /*
  42          * exynos_cpu_resume
  43          *
  44          * resume code entry for bootloader to call
  45          */
  46
  47 ENTRY(exynos_cpu_resume)
  48 #ifdef CONFIG_CACHE_L2X0
  49         mrc     p15, 0, r0, c0, c0, 0
  50         ldr     r1, =CPU_MASK
  51         and     r0, r0, r1
  52         ldr     r1, =CPU_CORTEX_A9
  53         cmp     r0, r1
  54         bleq    l2c310_early_resume
  55 #endif
  56         b       cpu_resume
  57 ENDPROC(exynos_cpu_resume)