| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | * $Id: thunk.S,v 1.2 2002/03/13 20:06:58 ak Exp $ |
| 7 | */ |
| 8 | |
| 9 | #include <linux/config.h> |
| 10 | #include <linux/linkage.h> |
| 11 | #include <asm/dwarf2.h> |
| 12 | #include <asm/calling.h> |
| 13 | #include <asm/rwlock.h> |
| 14 | |
| 15 | /* rdi: arg1 ... normal C conventions. rax is saved/restored. */ |
| 16 | .macro thunk name,func |
| 17 | .globl \name |
| 18 | \name: |
| 19 | CFI_STARTPROC |
| 20 | SAVE_ARGS |
| 21 | call \func |
| 22 | jmp restore |
| 23 | CFI_ENDPROC |
| 24 | .endm |
| 25 | |
| 26 | /* rdi: arg1 ... normal C conventions. rax is passed from C. */ |
| 27 | .macro thunk_retrax name,func |
| 28 | .globl \name |
| 29 | \name: |
| 30 | CFI_STARTPROC |
| 31 | SAVE_ARGS |
| 32 | call \func |
| 33 | jmp restore_norax |
| 34 | CFI_ENDPROC |
| 35 | .endm |
| 36 | |
| 37 | |
| 38 | .section .sched.text |
| 39 | #ifdef CONFIG_RWSEM_XCHGADD_ALGORITHM |
| 40 | thunk rwsem_down_read_failed_thunk,rwsem_down_read_failed |
| 41 | thunk rwsem_down_write_failed_thunk,rwsem_down_write_failed |
| 42 | thunk rwsem_wake_thunk,rwsem_wake |
| 43 | thunk rwsem_downgrade_thunk,rwsem_downgrade_wake |
| 44 | #endif |
| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 45 | |
| 46 | thunk __down_failed,__down |
| 47 | thunk_retrax __down_failed_interruptible,__down_interruptible |
| 48 | thunk_retrax __down_failed_trylock,__down_trylock |
| 49 | thunk __up_wakeup,__up |
| 50 | |
| 51 | /* SAVE_ARGS below is used only for the .cfi directives it contains. */ |
| 52 | CFI_STARTPROC |
| 53 | SAVE_ARGS |
| 54 | restore: |
| 55 | RESTORE_ARGS |
| 56 | ret |
| 57 | CFI_ENDPROC |
| 58 | |
| 59 | CFI_STARTPROC |
| 60 | SAVE_ARGS |
| 61 | restore_norax: |
| 62 | RESTORE_ARGS 1 |
| 63 | ret |
| 64 | CFI_ENDPROC |
| 65 | |
| 66 | #ifdef CONFIG_SMP |
| 67 | /* Support for read/write spinlocks. */ |
| 68 | .text |
| 69 | /* rax: pointer to rwlock_t */ |
| 70 | ENTRY(__write_lock_failed) |
| 71 | lock |
| 72 | addl $RW_LOCK_BIAS,(%rax) |
| 73 | 1: rep |
| 74 | nop |
| 75 | cmpl $RW_LOCK_BIAS,(%rax) |
| 76 | jne 1b |
| 77 | lock |
| 78 | subl $RW_LOCK_BIAS,(%rax) |
| 79 | jnz __write_lock_failed |
| 80 | ret |
| 81 | |
| 82 | /* rax: pointer to rwlock_t */ |
| 83 | ENTRY(__read_lock_failed) |
| 84 | lock |
| 85 | incl (%rax) |
| 86 | 1: rep |
| 87 | nop |
| 88 | cmpl $1,(%rax) |
| 89 | js 1b |
| 90 | lock |
| 91 | decl (%rax) |
| 92 | js __read_lock_failed |
| 93 | ret |
| 94 | #endif |