cpuidle, xenpv: Make more PARAVIRT_XXL noinstr clean

objtool found a few cases where this code called out into instrumented
code:

  vmlinux.o: warning: objtool: acpi_idle_enter_s2idle+0xde: call to wbinvd() leaves .noinstr.text section
  vmlinux.o: warning: objtool: default_idle+0x4: call to arch_safe_halt() leaves .noinstr.text section
  vmlinux.o: warning: objtool: xen_safe_halt+0xa: call to HYPERVISOR_sched_op.constprop.0() leaves .noinstr.text section

Solve this by:

 - marking arch_safe_halt(), wbinvd(), native_wbinvd() and
   HYPERVISOR_sched_op() as __always_inline().

 - Explicitly uninlining xen_safe_halt() and pv_native_wbinvd() [they were
   already uninlined by the compiler on use as function pointers] and
   annotating them as 'noinstr'.

 - Annotating pv_native_safe_halt() as 'noinstr'.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Tony Lindgren <tony@atomide.com>
Tested-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Srivatsa S. Bhat (VMware) <srivatsa@csail.mit.edu>
Reviewed-by: Juergen Gross <jgross@suse.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20230112195541.171918174@infradead.org

1 files changed, 4 insertions, 2 deletions

diff --git a/arch/x86/include/asm/paravirt.h b/arch/x86/include/asm/paravirt.h
index 73e9522db7c1..86c9d83e2c9b 100644
--- a/arch/x86/include/asm/paravirt.h
+++ b/arch/x86/include/asm/paravirt.h
@@ -168,7 +168,7 @@ static inline void __write_cr4(unsigned long x)
 	PVOP_VCALL1(cpu.write_cr4, x);
 }
 
-static inline void arch_safe_halt(void)
+static __always_inline void arch_safe_halt(void)
 {
 	PVOP_VCALL0(irq.safe_halt);
 }
@@ -178,7 +178,9 @@ static inline void halt(void)
 	PVOP_VCALL0(irq.halt);
 }
 
-static inline void wbinvd(void)
+extern noinstr void pv_native_wbinvd(void);
+
+static __always_inline void wbinvd(void)
 {
 	PVOP_ALT_VCALL0(cpu.wbinvd, "wbinvd", ALT_NOT(X86_FEATURE_XENPV));
 }