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- /*
- * x86-64 rwsem wrappers
- *
- * This interfaces the inline asm code to the slow-path
- * C routines. We need to save the call-clobbered regs
- * that the asm does not mark as clobbered, and move the
- * argument from %rax to %rdi.
- *
- * NOTE! We don't need to save %rax, because the functions
- * will always return the semaphore pointer in %rax (which
- * is also the input argument to these helpers)
- *
- * The following can clobber %rdx because the asm clobbers it:
- * call_rwsem_down_write_failed
- * call_rwsem_wake
- * but %rdi, %rsi, %rcx, %r8-r11 always need saving.
- */
- #include <linux/linkage.h>
- #include <asm/rwlock.h>
- #include <asm/alternative-asm.h>
- #include <asm/frame.h>
- #include <asm/dwarf2.h>
- #define save_common_regs \
- pushq %rdi; \
- pushq %rsi; \
- pushq %rcx; \
- pushq %r8; \
- pushq %r9; \
- pushq %r10; \
- pushq %r11
- #define restore_common_regs \
- popq %r11; \
- popq %r10; \
- popq %r9; \
- popq %r8; \
- popq %rcx; \
- popq %rsi; \
- popq %rdi
- /* Fix up special calling conventions */
- ENTRY(call_rwsem_down_read_failed)
- save_common_regs
- pushq %rdx
- movq %rax,%rdi
- call rwsem_down_read_failed
- popq %rdx
- restore_common_regs
- ret
- ENDPROC(call_rwsem_down_read_failed)
- ENTRY(call_rwsem_down_write_failed)
- save_common_regs
- movq %rax,%rdi
- call rwsem_down_write_failed
- restore_common_regs
- ret
- ENDPROC(call_rwsem_down_write_failed)
- ENTRY(call_rwsem_wake)
- decl %edx /* do nothing if still outstanding active readers */
- jnz 1f
- save_common_regs
- movq %rax,%rdi
- call rwsem_wake
- restore_common_regs
- 1: ret
- ENDPROC(call_rwsem_wake)
- /* Fix up special calling conventions */
- ENTRY(call_rwsem_downgrade_wake)
- save_common_regs
- pushq %rdx
- movq %rax,%rdi
- call rwsem_downgrade_wake
- popq %rdx
- restore_common_regs
- ret
- ENDPROC(call_rwsem_downgrade_wake)
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