git.zerfleddert.de Git - ms2-kexec/blob - entry-header.S

   1 #include <linux/init.h>
   2 #include <linux/linkage.h>
   3
   4 #include <asm/assembler.h>
   5 #include <asm/asm-offsets.h>
   6 #include <asm/errno.h>
   7 #include <asm/thread_info.h>
   8
   9 @ Bad Abort numbers
  10 @ -----------------
  11 @
  12 #define BAD_PREFETCH    0
  13 #define BAD_DATA        1
  14 #define BAD_ADDREXCPTN  2
  15 #define BAD_IRQ         3
  16 #define BAD_UNDEFINSTR  4
  17
  18 @
  19 @ Most of the stack format comes from struct pt_regs, but with
  20 @ the addition of 8 bytes for storing syscall args 5 and 6.
  21 @ This _must_ remain a multiple of 8 for EABI.
  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         .macro  get_thread_info, rd
  40         mov     \rd, sp, lsr #13
  41         mov     \rd, \rd, lsl #13
  42         .endm
  43
  44         .macro  alignment_trap, rtemp
  45 #ifdef CONFIG_ALIGNMENT_TRAP
  46         ldr     \rtemp, .LCcralign
  47         ldr     \rtemp, [\rtemp]
  48         mcr     p15, 0, \rtemp, c1, c0
  49 #endif
  50         .endm
  51
  52
  53 /*
  54  * These are the registers used in the syscall handler, and allow us to
  55  * have in theory up to 7 arguments to a function - r0 to r6.
  56  *
  57  * r7 is reserved for the system call number for thumb mode.
  58  *
  59  * Note that tbl == why is intentional.
  60  *
  61  * We must set at least "tsk" and "why" when calling ret_with_reschedule.
  62  */
  63 scno    .req    r7              @ syscall number
  64 tbl     .req    r8              @ syscall table pointer
  65 why     .req    r8              @ Linux syscall (!= 0)
  66 tsk     .req    r9              @ current thread_info