diff options
| author | Peter Zijlstra <peterz@infradead.org> | 2019-07-11 14:40:55 +0300 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2019-07-18 00:17:37 +0300 |
| commit | 55aedddb6149ab71bec9f050846855113977b033 (patch) | |
| tree | d9154c2a76eea96bdb139f1862a6f0ec72613a2d /arch/x86/xen | |
| parent | 406de552c2be6ded524c75d14a73cf7f027f587e (diff) | |
| download | linux-55aedddb6149ab71bec9f050846855113977b033.tar.xz | |
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')
| -rw-r--r-- | arch/x86/xen/enlighten_pv.c | 3 | ||||
| -rw-r--r-- | arch/x86/xen/mmu_pv.c | 12 | ||||
| -rw-r--r-- | arch/x86/xen/xen-asm.S | 16 | ||||
| -rw-r--r-- | arch/x86/xen/xen-ops.h | 3 |
4 files changed, 22 insertions, 12 deletions
diff --git a/arch/x86/xen/enlighten_pv.c b/arch/x86/xen/enlighten_pv.c index 4722ba2966ac..26b63d051bda 100644 --- a/arch/x86/xen/enlighten_pv.c +++ b/arch/x86/xen/enlighten_pv.c @@ -998,7 +998,8 @@ void __init xen_setup_vcpu_info_placement(void) __PV_IS_CALLEE_SAVE(xen_irq_disable_direct); pv_ops.irq.irq_enable = __PV_IS_CALLEE_SAVE(xen_irq_enable_direct); - pv_ops.mmu.read_cr2 = xen_read_cr2_direct; + pv_ops.mmu.read_cr2 = + __PV_IS_CALLEE_SAVE(xen_read_cr2_direct); } } diff --git a/arch/x86/xen/mmu_pv.c b/arch/x86/xen/mmu_pv.c index f6e5eeecfc69..26e8b326966d 100644 --- a/arch/x86/xen/mmu_pv.c +++ b/arch/x86/xen/mmu_pv.c @@ -1307,16 +1307,6 @@ static void xen_write_cr2(unsigned long cr2) this_cpu_read(xen_vcpu)->arch.cr2 = cr2; } -static unsigned long xen_read_cr2(void) -{ - return this_cpu_read(xen_vcpu)->arch.cr2; -} - -unsigned long xen_read_cr2_direct(void) -{ - return this_cpu_read(xen_vcpu_info.arch.cr2); -} - static noinline void xen_flush_tlb(void) { struct mmuext_op *op; @@ -2397,7 +2387,7 @@ static void xen_leave_lazy_mmu(void) } static const struct pv_mmu_ops xen_mmu_ops __initconst = { - .read_cr2 = xen_read_cr2, + .read_cr2 = __PV_IS_CALLEE_SAVE(xen_read_cr2), .write_cr2 = xen_write_cr2, .read_cr3 = xen_read_cr3, 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); diff --git a/arch/x86/xen/xen-ops.h b/arch/x86/xen/xen-ops.h index 2f111f47ba98..45a441c33d6d 100644 --- a/arch/x86/xen/xen-ops.h +++ b/arch/x86/xen/xen-ops.h @@ -134,6 +134,9 @@ __visible void xen_irq_disable_direct(void); __visible unsigned long xen_save_fl_direct(void); __visible void xen_restore_fl_direct(unsigned long); +__visible unsigned long xen_read_cr2(void); +__visible unsigned long xen_read_cr2_direct(void); + /* These are not functions, and cannot be called normally */ __visible void xen_iret(void); __visible void xen_sysret32(void); |