x86/fpu: Make os_xrstor_booting() private

mainline inclusion
from mainline-v5.16-rc1
commit b579d0c3
category: feature
bugzilla: https://gitee.com/openeuler/intel-kernel/issues/I590ZC
CVE: NA

Intel-SIG: commit b579d0c3 x86/fpu: Make os_xrstor_booting() private.

--------------------------------

It's only required in the xstate init code.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NBorislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20211015011539.455836597@linutronix.deSigned-off-by: NLin Wang <lin.x.wang@intel.com>
Signed-off-by: NAichun Shi <aichun.shi@intel.com>

arch/x86/include/asm/fpu/internal.h

@@ -233,31 +233,6 @@ static inline void fxsave(struct fxregs_state *fx)
 		     : "D" (st), "m" (*st), "a" (lmask), "d" (hmask)	\
 		     : "memory")
 
-/*
- * This function is called only during boot time when x86 caps are not set
- * up and alternative can not be used yet.
- */
-static inline void os_xrstor_booting(struct xregs_state *xstate)
-{
-	u64 mask = xfeatures_mask_fpstate();
-	u32 lmask = mask;
-	u32 hmask = mask >> 32;
-	int err;
-
-	WARN_ON(system_state != SYSTEM_BOOTING);
-
-	if (boot_cpu_has(X86_FEATURE_XSAVES))
-		XSTATE_OP(XRSTORS, xstate, lmask, hmask, err);
-	else
-		XSTATE_OP(XRSTOR, xstate, lmask, hmask, err);
-
-	/*
-	 * We should never fault when copying from a kernel buffer, and the FPU
-	 * state we set at boot time should be valid.
-	 */
-	WARN_ON_FPU(err);
-}
-
 /*
  * Save processor xstate to xsave area.
  *

arch/x86/kernel/fpu/xstate.c

@@ -350,6 +350,29 @@ static void __init print_xstate_offset_size(void)
 	}
 }
 
+/*
+ * This function is called only during boot time when x86 caps are not set
+ * up and alternative can not be used yet.
+ */
+static __init void os_xrstor_booting(struct xregs_state *xstate)
+{
+	u64 mask = xfeatures_mask_fpstate();
+	u32 lmask = mask;
+	u32 hmask = mask >> 32;
+	int err;
+
+	if (cpu_feature_enabled(X86_FEATURE_XSAVES))
+		XSTATE_OP(XRSTORS, xstate, lmask, hmask, err);
+	else
+		XSTATE_OP(XRSTOR, xstate, lmask, hmask, err);
+
+	/*
+	 * We should never fault when copying from a kernel buffer, and the FPU
+	 * state we set at boot time should be valid.
+	 */
+	WARN_ON_FPU(err);
+}
+
 /*
  * All supported features have either init state all zeros or are
  * handled in setup_init_fpu() individually. This is an explicit