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 @
  23 #define S_OFF           8
  24
  25 /*
  26  * The SWI code relies on the fact that R0 is at the bottom of the stack
  27  * (due to slow/fast restore user regs).
  28  */
  29 #if S_R0 != 0
  30 #error "Please fix"
  31 #endif
  32
  33         .macro  zero_fp
  34 #ifdef CONFIG_FRAME_POINTER
  35         mov     fp, #0
  36 #endif
  37         .endm
  38
  39 #if __LINUX_ARM_ARCH__ >= 6
  40         .macro  disable_irq
  41         cpsid   i
  42         .endm
  43
  44         .macro  enable_irq
  45         cpsie   i
  46         .endm
  47 #else
  48         .macro  disable_irq
  49         msr     cpsr_c, #PSR_I_BIT | SVC_MODE
  50         .endm
  51
  52         .macro  enable_irq
  53         msr     cpsr_c, #SVC_MODE
  54         .endm
  55 #endif
  56
  57         .macro  get_thread_info, rd
  58         mov     \rd, sp, lsr #13
  59         mov     \rd, \rd, lsl #13
  60         .endm
  61
  62         .macro  alignment_trap, rtemp
  63 #ifdef CONFIG_ALIGNMENT_TRAP
  64         ldr     \rtemp, .LCcralign
  65         ldr     \rtemp, [\rtemp]
  66         mcr     p15, 0, \rtemp, c1, c0
  67 #endif
  68         .endm
  69
  70
  71 /*
  72  * These are the registers used in the syscall handler, and allow us to
  73  * have in theory up to 7 arguments to a function - r0 to r6.
  74  *
  75  * r7 is reserved for the system call number for thumb mode.
  76  *
  77  * Note that tbl == why is intentional.
  78  *
  79  * We must set at least "tsk" and "why" when calling ret_with_reschedule.
  80  */
  81 scno    .req    r7              @ syscall number
  82 tbl     .req    r8              @ syscall table pointer
  83 why     .req    r8              @ Linux syscall (!= 0)
  84 tsk     .req    r9              @ current thread_info