x86: make some functions and variables static rather than extern

The functions and variables touched by this commit can be static,
as they are only used within the same unit. This in turn addresses
the absence of declarations that violates MISRA C:2012 Rule 8.4.

Fixes: 741367e77d ("mce: Clean-up mcheck_init handler")
Fixes: 45f57813f6 ("x86/MCE: implement recoverscan for AMD")
Fixes: 155587481e ("x86/microcode: Scan the initramfs payload for microcode blob")
Fixes: af50dd63cf ("Pull nmi/traps changes from Linux 2.6.14.")
Fixes: fef244b179 ("x86/spec-ctrl: Knobs for STIBP and PSFD, and follow hardware STIBP hint")
Signed-off-by: Nicola Vetrini <nicola.vetrini@bugseng.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>

xen/arch/x86/cpu/mcheck/mce.c

@@ -599,7 +599,7 @@ unsigned int mce_firstbank(struct cpuinfo_x86 *c)
            c->x86_vendor == X86_VENDOR_INTEL && c->x86_model < 0x1a;
 }
 
-int show_mca_info(int inited, struct cpuinfo_x86 *c)
+static int show_mca_info(int inited, struct cpuinfo_x86 *c)
 {
     static enum mcheck_type g_type = mcheck_unset;
 

xen/arch/x86/cpu/mcheck/mce_amd.c

@@ -87,7 +87,7 @@ enum mc_ec_type {
     MC_EC_BUS_TYPE = 0x0800,
 };
 
-enum mc_ec_type
+static enum mc_ec_type
 mc_ec2type(uint16_t errorcode)
 {
     if ( errorcode & MC_EC_BUS_TYPE )

xen/arch/x86/cpu/microcode/core.c

@@ -149,7 +149,7 @@ static int __init cf_check parse_ucode(const char *s)
 }
 custom_param("ucode", parse_ucode);
 
-void __init microcode_scan_module(
+static void __init microcode_scan_module(
     unsigned long *module_map,
     const multiboot_info_t *mbi)
 {

xen/arch/x86/nmi.c

@@ -108,7 +108,7 @@ static unsigned int lapic_nmi_owner;
  *     be enabled
  * -1: the lapic NMI watchdog is disabled, but can be enabled
  */
-int nmi_active;
+static int nmi_active;
 
 #define K7_EVNTSEL_ENABLE	(1 << 22)
 #define K7_EVNTSEL_INT		(1 << 20)

xen/arch/x86/spec_ctrl.c

@@ -43,9 +43,9 @@ static enum ind_thunk {
 } opt_thunk __initdata = THUNK_DEFAULT;
 
 static int8_t __initdata opt_ibrs = -1;
-int8_t __initdata opt_stibp = -1;
+static int8_t __initdata opt_stibp = -1;
 bool __ro_after_init opt_ssbd;
-int8_t __initdata opt_psfd = -1;
+static int8_t __initdata opt_psfd = -1;
 
 int8_t __ro_after_init opt_ibpb_ctxt_switch = -1;
 int8_t __read_mostly opt_eager_fpu = -1;