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| author | Peter Zijlstra <peterz@infradead.org> | 2019-07-11 13:40:55 +0200 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2019-07-17 23:17:37 +0200 |
| commit | 55aedddb6149ab71bec9f050846855113977b033 (patch) | |
| tree | d9154c2a76eea96bdb139f1862a6f0ec72613a2d /arch/x86/xen/xen-asm.S | |
| parent | 406de552c2be6ded524c75d14a73cf7f027f587e (diff) | |
| download | linux-55aedddb6149ab71bec9f050846855113977b033.tar.gz linux-55aedddb6149ab71bec9f050846855113977b033.tar.bz2 linux-55aedddb6149ab71bec9f050846855113977b033.zip | |
x86/paravirt: Make read_cr2() CALLEE_SAVE
The one paravirt read_cr2() implementation (Xen) is actually quite trivial
and doesn't need to clobber anything other than the return register.
Making read_cr2() CALLEE_SAVE avoids all the PUSH/POP nonsense and allows
more convenient use from assembly.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Juergen Gross <jgross@suse.com>
Cc: bp@alien8.de
Cc: rostedt@goodmis.org
Cc: luto@kernel.org
Cc: torvalds@linux-foundation.org
Cc: hpa@zytor.com
Cc: dave.hansen@linux.intel.com
Cc: zhe.he@windriver.com
Cc: joel@joelfernandes.org
Cc: devel@etsukata.com
Link: https://lkml.kernel.org/r/20190711114335.887392493@infradead.org
Diffstat (limited to 'arch/x86/xen/xen-asm.S')
| -rw-r--r-- | arch/x86/xen/xen-asm.S | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/arch/x86/xen/xen-asm.S b/arch/x86/xen/xen-asm.S index 8019edd0125c..be104eef80be 100644 --- a/arch/x86/xen/xen-asm.S +++ b/arch/x86/xen/xen-asm.S @@ -10,6 +10,7 @@ #include <asm/percpu.h> #include <asm/processor-flags.h> #include <asm/frame.h> +#include <asm/asm.h> #include <linux/linkage.h> @@ -135,3 +136,18 @@ ENTRY(check_events) FRAME_END ret ENDPROC(check_events) + +ENTRY(xen_read_cr2) + FRAME_BEGIN + _ASM_MOV PER_CPU_VAR(xen_vcpu), %_ASM_AX + _ASM_MOV XEN_vcpu_info_arch_cr2(%_ASM_AX), %_ASM_AX + FRAME_END + ret + ENDPROC(xen_read_cr2); + +ENTRY(xen_read_cr2_direct) + FRAME_BEGIN + _ASM_MOV PER_CPU_VAR(xen_vcpu_info) + XEN_vcpu_info_arch_cr2, %_ASM_AX + FRAME_END + ret + ENDPROC(xen_read_cr2_direct); |