arch/x86_64/lib/thunk.S

   1 /*
   2  * Save registers before calling assembly functions. This avoids
   3  * disturbance of register allocation in some inline assembly constructs.
   4  * Copyright 2001,2002 by Andi Kleen, SuSE Labs.
   5  * Subject to the GNU public license, v.2. No warranty of any kind.
   6  */
   7
   8         #include <linux/config.h>
   9         #include <linux/linkage.h>
  10         #include <asm/dwarf2.h>
  11         #include <asm/calling.h>
  12         #include <asm/rwlock.h>
  13
  14         /* rdi: arg1 ... normal C conventions. rax is saved/restored. */
  15         .macro thunk name,func
  16         .globl \name
  17 \name:
  18         CFI_STARTPROC
  19         SAVE_ARGS
  20         call \func
  21         jmp  restore
  22         CFI_ENDPROC
  23         .endm
  24
  25         /* rdi: arg1 ... normal C conventions. rax is passed from C. */
  26         .macro thunk_retrax name,func
  27         .globl \name
  28 \name:
  29         CFI_STARTPROC
  30         SAVE_ARGS
  31         call \func
  32         jmp  restore_norax
  33         CFI_ENDPROC
  34         .endm
  35
  36
  37         .section .sched.text
  38 #ifdef CONFIG_RWSEM_XCHGADD_ALGORITHM
  39         thunk rwsem_down_read_failed_thunk,rwsem_down_read_failed
  40         thunk rwsem_down_write_failed_thunk,rwsem_down_write_failed
  41         thunk rwsem_wake_thunk,rwsem_wake
  42         thunk rwsem_downgrade_thunk,rwsem_downgrade_wake
  43 #endif
  44
  45         thunk __down_failed,__down
  46         thunk_retrax __down_failed_interruptible,__down_interruptible
  47         thunk_retrax __down_failed_trylock,__down_trylock
  48         thunk __up_wakeup,__up
  49
  50 #ifdef CONFIG_TRACE_IRQFLAGS
  51         thunk trace_hardirqs_on_thunk,trace_hardirqs_on
  52         thunk trace_hardirqs_off_thunk,trace_hardirqs_off
  53 #endif
  54
  55         /* SAVE_ARGS below is used only for the .cfi directives it contains. */
  56         CFI_STARTPROC
  57         SAVE_ARGS
  58 restore:
  59         RESTORE_ARGS
  60         ret
  61         CFI_ENDPROC
  62
  63         CFI_STARTPROC
  64         SAVE_ARGS
  65 restore_norax:
  66         RESTORE_ARGS 1
  67         ret
  68         CFI_ENDPROC