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Diffstat (limited to 'arch/x86_64/lib/thunk.S')
| -rw-r--r-- | arch/x86_64/lib/thunk.S | 95 |
1 files changed, 95 insertions, 0 deletions
diff --git a/arch/x86_64/lib/thunk.S b/arch/x86_64/lib/thunk.S new file mode 100644 index 000000000000..acc1e2ca7ed7 --- /dev/null +++ b/arch/x86_64/lib/thunk.S @@ -0,0 +1,95 @@ + /* + * Save registers before calling assembly functions. This avoids + * disturbance of register allocation in some inline assembly constructs. + * Copyright 2001,2002 by Andi Kleen, SuSE Labs. + * Subject to the GNU public license, v.2. No warranty of any kind. + * $Id: thunk.S,v 1.2 2002/03/13 20:06:58 ak Exp $ + */ + + #include <linux/config.h> + #include <linux/linkage.h> + #include <asm/dwarf2.h> + #include <asm/calling.h> + #include <asm/rwlock.h> + + /* rdi: arg1 ... normal C conventions. rax is saved/restored. */ + .macro thunk name,func + .globl \name +\name: + CFI_STARTPROC + SAVE_ARGS + call \func + jmp restore + CFI_ENDPROC + .endm + + /* rdi: arg1 ... normal C conventions. rax is passed from C. */ + .macro thunk_retrax name,func + .globl \name +\name: + CFI_STARTPROC + SAVE_ARGS + call \func + jmp restore_norax + CFI_ENDPROC + .endm + + + .section .sched.text +#ifdef CONFIG_RWSEM_XCHGADD_ALGORITHM + thunk rwsem_down_read_failed_thunk,rwsem_down_read_failed + thunk rwsem_down_write_failed_thunk,rwsem_down_write_failed + thunk rwsem_wake_thunk,rwsem_wake + thunk rwsem_downgrade_thunk,rwsem_downgrade_wake +#endif + thunk do_softirq_thunk,do_softirq + + thunk __down_failed,__down + thunk_retrax __down_failed_interruptible,__down_interruptible + thunk_retrax __down_failed_trylock,__down_trylock + thunk __up_wakeup,__up + + /* SAVE_ARGS below is used only for the .cfi directives it contains. */ + CFI_STARTPROC + SAVE_ARGS +restore: + RESTORE_ARGS + ret + CFI_ENDPROC + + CFI_STARTPROC + SAVE_ARGS +restore_norax: + RESTORE_ARGS 1 + ret + CFI_ENDPROC + +#ifdef CONFIG_SMP +/* Support for read/write spinlocks. */ + .text +/* rax: pointer to rwlock_t */ +ENTRY(__write_lock_failed) + lock + addl $RW_LOCK_BIAS,(%rax) +1: rep + nop + cmpl $RW_LOCK_BIAS,(%rax) + jne 1b + lock + subl $RW_LOCK_BIAS,(%rax) + jnz __write_lock_failed + ret + +/* rax: pointer to rwlock_t */ +ENTRY(__read_lock_failed) + lock + incl (%rax) +1: rep + nop + cmpl $1,(%rax) + js 1b + lock + decl (%rax) + js __read_lock_failed + ret +#endif |