arch/arm/kernel/entry-header.S

   1 #include <linux/config.h>
   2 #include <linux/init.h>
   3 #include <linux/linkage.h>
   4
   5 #include <asm/assembler.h>
   6 #include <asm/asm-offsets.h>
   7 #include <asm/errno.h>
   8 #include <asm/thread_info.h>
   9
  10 @ Bad Abort numbers
  11 @ -----------------
  12 @
  13 #define BAD_PREFETCH    0
  14 #define BAD_DATA        1
  15 #define BAD_ADDREXCPTN  2
  16 #define BAD_IRQ         3
  17 #define BAD_UNDEFINSTR  4
  18
  19 @
  20 @ Most of the stack format comes from struct pt_regs, but with
  21 @ the addition of 8 bytes for storing syscall args 5 and 6.
  22 @ This _must_ remain a multiple of 8 for EABI.
  23 @
  24 #define S_OFF           8
  25
  26 /*
  27  * The SWI code relies on the fact that R0 is at the bottom of the stack
  28  * (due to slow/fast restore user regs).
  29  */
  30 #if S_R0 != 0
  31 #error "Please fix"
  32 #endif
  33
  34         .macro  zero_fp
  35 #ifdef CONFIG_FRAME_POINTER
  36         mov     fp, #0
  37 #endif
  38         .endm
  39
  40 #if __LINUX_ARM_ARCH__ >= 6
  41         .macro  disable_irq
  42         cpsid   i
  43         .endm
  44
  45         .macro  enable_irq
  46         cpsie   i
  47         .endm
  48 #else
  49         .macro  disable_irq
  50         msr     cpsr_c, #PSR_I_BIT | SVC_MODE
  51         .endm
  52
  53         .macro  enable_irq
  54         msr     cpsr_c, #SVC_MODE
  55         .endm
  56 #endif
  57
  58         .macro  get_thread_info, rd
  59         mov     \rd, sp, lsr #13
  60         mov     \rd, \rd, lsl #13
  61         .endm
  62
  63         .macro  alignment_trap, rtemp
  64 #ifdef CONFIG_ALIGNMENT_TRAP
  65         ldr     \rtemp, .LCcralign
  66         ldr     \rtemp, [\rtemp]
  67         mcr     p15, 0, \rtemp, c1, c0
  68 #endif
  69         .endm
  70
  71
  72 /*
  73  * These are the registers used in the syscall handler, and allow us to
  74  * have in theory up to 7 arguments to a function - r0 to r6.
  75  *
  76  * r7 is reserved for the system call number for thumb mode.
  77  *
  78  * Note that tbl == why is intentional.
  79  *
  80  * We must set at least "tsk" and "why" when calling ret_with_reschedule.
  81  */
  82 scno    .req    r7              @ syscall number
  83 tbl     .req    r8              @ syscall table pointer
  84 why     .req    r8              @ Linux syscall (!= 0)
  85 tsk     .req    r9              @ current thread_info