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/** @file sync_asm.S
*
* @brief locks.
*
* @author Hanjie Wu (hanjiew)
* @bug No functional bugs
*/
.text
#define EFL_IF 0x00000200
.global save_clear_if
.type save_clear_if, %function
save_clear_if:
pushf
pop %eax
cli
ret
.global restore_if
.type restore_if, %function
restore_if:
mov 0x4(%esp), %eax
push %eax
popf
ret
.global spl_lock
.type spl_lock, %function
spl_lock:
pushf
pop %edx
cli
mov 0x4(%esp), %esi
mov $1, %edi
.spl_lock_try:
xor %eax, %eax
lock cmpxchg %edi, (%esi)
test %eax, %eax
jnz .spl_lock_try
mov %edx, %eax
ret
.global spl_unlock
.type spl_unlock, %function
spl_unlock:
mov 0x8(%esp), %eax
mov 0x4(%esp), %esi
xor %edx, %edx
mov %edx, (%esi)
push %eax
popf
ret
.global yield_to_spl_unlock
.type yield_to_spl_unlock, %function
yield_to_spl_unlock:
mov 0xc(%esp), %edi
mov 0x8(%esp), %esi
mov 0x4(%esp), %eax
push %edi /* old_if, will be restored when switching back */
push %ebx
push %ebp
mov %esi, %ebx
push %esp
push %eax
call save_and_setup_env
mov %eax, %esp
xor %eax, %eax
mov %eax, (%ebx)
pop %ebp
pop %ebx
popf
ret
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