94 lines
2.3 KiB
ArmAsm
94 lines
2.3 KiB
ArmAsm
/*
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* x86-64 rwsem wrappers
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*
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* This interfaces the inline asm code to the slow-path
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* C routines. We need to save the call-clobbered regs
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* that the asm does not mark as clobbered, and move the
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* argument from %rax to %rdi.
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*
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* NOTE! We don't need to save %rax, because the functions
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* will always return the semaphore pointer in %rax (which
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* is also the input argument to these helpers)
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*
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* The following can clobber %rdx because the asm clobbers it:
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* call_rwsem_down_write_failed
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* call_rwsem_wake
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* but %rdi, %rsi, %rcx, %r8-r11 always need saving.
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*/
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#include <linux/linkage.h>
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#include <asm/rwlock.h>
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#include <asm/alternative-asm.h>
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#include <asm/frame.h>
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#include <asm/dwarf2.h>
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#define save_common_regs \
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pushq_cfi %rdi; CFI_REL_OFFSET rdi, 0; \
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pushq_cfi %rsi; CFI_REL_OFFSET rsi, 0; \
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pushq_cfi %rcx; CFI_REL_OFFSET rcx, 0; \
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pushq_cfi %r8; CFI_REL_OFFSET r8, 0; \
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pushq_cfi %r9; CFI_REL_OFFSET r9, 0; \
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pushq_cfi %r10; CFI_REL_OFFSET r10, 0; \
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pushq_cfi %r11; CFI_REL_OFFSET r11, 0
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#define restore_common_regs \
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popq_cfi %r11; CFI_RESTORE r11; \
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popq_cfi %r10; CFI_RESTORE r10; \
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popq_cfi %r9; CFI_RESTORE r9; \
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popq_cfi %r8; CFI_RESTORE r8; \
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popq_cfi %rcx; CFI_RESTORE rcx; \
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popq_cfi %rsi; CFI_RESTORE rsi; \
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popq_cfi %rdi; CFI_RESTORE rdi
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/* Fix up special calling conventions */
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ENTRY(call_rwsem_down_read_failed)
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CFI_STARTPROC
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save_common_regs
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pushq_cfi %rdx
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CFI_REL_OFFSET rdx, 0
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movq %rax,%rdi
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call rwsem_down_read_failed
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popq_cfi %rdx
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CFI_RESTORE rdx
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restore_common_regs
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ret
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CFI_ENDPROC
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ENDPROC(call_rwsem_down_read_failed)
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ENTRY(call_rwsem_down_write_failed)
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CFI_STARTPROC
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save_common_regs
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movq %rax,%rdi
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call rwsem_down_write_failed
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restore_common_regs
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ret
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CFI_ENDPROC
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ENDPROC(call_rwsem_down_write_failed)
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ENTRY(call_rwsem_wake)
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CFI_STARTPROC
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decl %edx /* do nothing if still outstanding active readers */
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jnz 1f
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save_common_regs
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movq %rax,%rdi
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call rwsem_wake
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restore_common_regs
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1: ret
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CFI_ENDPROC
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ENDPROC(call_rwsem_wake)
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/* Fix up special calling conventions */
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ENTRY(call_rwsem_downgrade_wake)
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CFI_STARTPROC
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save_common_regs
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pushq_cfi %rdx
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CFI_REL_OFFSET rdx, 0
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movq %rax,%rdi
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call rwsem_downgrade_wake
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popq_cfi %rdx
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CFI_RESTORE rdx
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restore_common_regs
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ret
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CFI_ENDPROC
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ENDPROC(call_rwsem_downgrade_wake)
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