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     r1, 1f
  28         bx      r1
  29
  30 ENDPROC(shmobile_boot_vector)
  31
  32         .align  2
  33         .globl  shmobile_boot_fn
  34 shmobile_boot_fn:
  35 1:      .space  4
  36         .globl  shmobile_boot_size
  37 shmobile_boot_size:
  38         .long   . - shmobile_boot_vector
  39
  40 /*
  41  * Per-CPU SMP boot function/argument selection code based on MPIDR
  42  */
  43
  44 ENTRY(shmobile_smp_boot)
  45         mrc     p15, 0, r1, c0, c0, 5           @ r1 = MPIDR
  46         and     r0, r1, #0xffffff               @ MPIDR_HWID_BITMASK
  47                                                 @ r0 = cpu_logical_map() value
  48         mov     r1, #0                          @ r1 = CPU index
  49         adr     r2, 1f
  50         ldmia   r2, {r5, r6, r7}
  51         add     r5, r5, r2                      @ array of per-cpu mpidr values
  52         add     r6, r6, r2                      @ array of per-cpu functions
  53         add     r7, r7, r2                      @ array of per-cpu arguments
  54
  55 shmobile_smp_boot_find_mpidr:
  56         ldr     r8, [r5, r1, lsl #2]
  57         cmp     r8, r0
  58         bne     shmobile_smp_boot_next
  59
  60         ldr     r9, [r6, r1, lsl #2]
  61         cmp     r9, #0
  62         bne     shmobile_smp_boot_found
  63
  64 shmobile_smp_boot_next:
  65         add     r1, r1, #1
  66         cmp     r1, #NR_CPUS
  67         blo     shmobile_smp_boot_find_mpidr
  68
  69         b       shmobile_smp_sleep
  70
  71 shmobile_smp_boot_found:
  72         ldr     r0, [r7, r1, lsl #2]
  73         ret     r9
  74 ENDPROC(shmobile_smp_boot)
  75
  76 ENTRY(shmobile_smp_sleep)
  77         wfi
  78         b       shmobile_smp_boot
  79 ENDPROC(shmobile_smp_sleep)
  80
  81         .align  2
  82 1:      .long   shmobile_smp_mpidr - .
  83         .long   shmobile_smp_fn - 1b
  84         .long   shmobile_smp_arg - 1b
  85
  86         .bss
  87         .globl  shmobile_smp_mpidr
  88 shmobile_smp_mpidr:
  89         .space  NR_CPUS * 4
  90         .globl  shmobile_smp_fn
  91 shmobile_smp_fn:
  92         .space  NR_CPUS * 4
  93         .globl  shmobile_smp_arg
  94 shmobile_smp_arg:
  95         .space  NR_CPUS * 4