kernel/arch/arm/mach-shmobile/headsmp.S

   1 /*
   2  * SMP support for R-Mobile / SH-Mobile
   3  *
   4  * Copyright (C) 2010  Magnus Damm
   5  * Copyright (C) 2010  Takashi Yoshii
   6  *
   7  * Based on vexpress, Copyright (c) 2003 ARM Limited, All Rights Reserved
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License version 2 as
  11  * published by the Free Software Foundation.
  12  */
  13 #include <linux/init.h>
  14 #include <linux/linkage.h>
  15 #include <linux/threads.h>
  16 #include <asm/assembler.h>
  17 #include <asm/memory.h>
  18
  19 /*
  20  * Reset vector for secondary CPUs.
  21  * This will be mapped at address 0 by SBAR register.
  22  * We need _long_ jump to the physical address.
  23  */
  24         .arm
  25         .align  12
  26 ENTRY(shmobile_boot_vector)
  27         ldr     r0, 2f
  28         ldr     r1, 1f
  29         bx      r1
  30
  31 ENDPROC(shmobile_boot_vector)
  32
  33         .align  2
  34         .globl  shmobile_boot_fn
  35 shmobile_boot_fn:
  36 1:      .space  4
  37         .globl  shmobile_boot_arg
  38 shmobile_boot_arg:
  39 2:      .space  4
  40         .globl  shmobile_boot_size
  41 shmobile_boot_size:
  42         .long   . - shmobile_boot_vector
  43
  44 /*
  45  * Per-CPU SMP boot function/argument selection code based on MPIDR
  46  */
  47
  48 ENTRY(shmobile_smp_boot)
  49                                                 @ r0 = MPIDR_HWID_BITMASK
  50         mrc     p15, 0, r1, c0, c0, 5           @ r1 = MPIDR
  51         and     r0, r1, r0                      @ r0 = cpu_logical_map() value
  52         mov     r1, #0                          @ r1 = CPU index
  53         adr     r5, 1f                          @ array of per-cpu mpidr values
  54         adr     r6, 2f                          @ array of per-cpu functions
  55         adr     r7, 3f                          @ array of per-cpu arguments
  56
  57 shmobile_smp_boot_find_mpidr:
  58         ldr     r8, [r5, r1, lsl #2]
  59         cmp     r8, r0
  60         bne     shmobile_smp_boot_next
  61
  62         ldr     r9, [r6, r1, lsl #2]
  63         cmp     r9, #0
  64         bne     shmobile_smp_boot_found
  65
  66 shmobile_smp_boot_next:
  67         add     r1, r1, #1
  68         cmp     r1, #NR_CPUS
  69         blo     shmobile_smp_boot_find_mpidr
  70
  71         b       shmobile_smp_sleep
  72
  73 shmobile_smp_boot_found:
  74         ldr     r0, [r7, r1, lsl #2]
  75         ret     r9
  76 ENDPROC(shmobile_smp_boot)
  77
  78 ENTRY(shmobile_smp_sleep)
  79         wfi
  80         b       shmobile_smp_boot
  81 ENDPROC(shmobile_smp_sleep)
  82
  83         .globl  shmobile_smp_mpidr
  84 shmobile_smp_mpidr:
  85 1:      .space  NR_CPUS * 4
  86         .globl  shmobile_smp_fn
  87 shmobile_smp_fn:
  88 2:      .space  NR_CPUS * 4
  89         .globl  shmobile_smp_arg
  90 shmobile_smp_arg:
  91 3:      .space  NR_CPUS * 4