| /* |
| * 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) |
| decw %dx /* 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) |
