arch/arm/mach-uniphier/headsmp.S

   1 /*
   2  * Copyright (C) 2015 Masahiro Yamada <yamada.masahiro@socionext.com>
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  */
  14
  15 #include <linux/linkage.h>
  16 #include <asm/assembler.h>
  17 #include <asm/cp15.h>
  18
  19 ENTRY(uniphier_smp_trampoline)
  20 ARM_BE8(setend  be)                     @ ensure we are in BE8 mode
  21         mrc     p15, 0, r0, c0, c0, 5   @ MPIDR (Multiprocessor Affinity Reg)
  22         and     r2, r0, #0x3            @ CPU ID
  23         ldr     r1, uniphier_smp_trampoline_jump
  24         ldr     r3, uniphier_smp_trampoline_poll_addr
  25         mrc     p15, 0, r0, c1, c0, 0   @ SCTLR (System Control Register)
  26         orr     r0, r0, #CR_I           @ Enable ICache
  27         bic     r0, r0, #(CR_C | CR_M)  @ Disable MMU and Dcache
  28         mcr     p15, 0, r0, c1, c0, 0
  29         b       1f                      @ cache the following 5 instructions
  30 0:      wfe
  31 1:      ldr     r0, [r3]
  32         cmp     r0, r2
  33         bxeq    r1                      @ branch to secondary_startup
  34         b       0b
  35         .globl  uniphier_smp_trampoline_jump
  36 uniphier_smp_trampoline_jump:
  37         .word   0                       @ set virt_to_phys(secondary_startup)
  38         .globl  uniphier_smp_trampoline_poll_addr
  39 uniphier_smp_trampoline_poll_addr:
  40         .word   0                       @ set CPU ID to be kicked to this reg
  41         .globl  uniphier_smp_trampoline_end
  42 uniphier_smp_trampoline_end:
  43 ENDPROC(uniphier_smp_trampoline)