system: Replace arch_type global by qemu_arch_available() helper

qemu_arch_available() is a bit simpler to understand while
reviewing than the undocumented arch_type variable.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-Id: <20250305005225.95051-5-philmd@linaro.org>

hw/scsi/scsi-disk.c

@@ -3165,7 +3165,7 @@ static void scsi_property_add_specifics(DeviceClass *dc)
     ObjectClass *oc = OBJECT_CLASS(dc);
 
     /* The loadparm property is only supported on s390x */
-    if (arch_type & QEMU_ARCH_S390X) {
+    if (qemu_arch_available(QEMU_ARCH_S390X)) {
         object_class_property_add_str(oc, "loadparm",
                                       scsi_property_get_loadparm,
                                       scsi_property_set_loadparm);

include/system/arch_init.h

@@ -25,6 +25,6 @@ enum {
     QEMU_ARCH_LOONGARCH = (1 << 23),
 };
 
-extern const uint32_t arch_type;
+bool qemu_arch_available(unsigned qemu_arch_mask);
 
 #endif

system/arch_init.c

@@ -24,4 +24,7 @@
 #include "qemu/osdep.h"
 #include "system/arch_init.h"
 
-const uint32_t arch_type = QEMU_ARCH;
+bool qemu_arch_available(unsigned qemu_arch_mask)
+{
+    return qemu_arch_mask & QEMU_ARCH;
+}

system/qdev-monitor.c

@@ -132,7 +132,7 @@ static const char *qdev_class_get_alias(DeviceClass *dc)
 
     for (i = 0; qdev_alias_table[i].typename; i++) {
         if (qdev_alias_table[i].arch_mask &&
-            !(qdev_alias_table[i].arch_mask & arch_type)) {
+            !qemu_arch_available(qdev_alias_table[i].arch_mask)) {
             continue;
         }
 
@@ -218,7 +218,7 @@ static const char *find_typename_by_alias(const char *alias)
 
     for (i = 0; qdev_alias_table[i].alias; i++) {
         if (qdev_alias_table[i].arch_mask &&
-            !(qdev_alias_table[i].arch_mask & arch_type)) {
+            !qemu_arch_available(qdev_alias_table[i].arch_mask)) {
             continue;
         }
 

system/vl.c

@@ -878,11 +878,11 @@ static void help(int exitcode)
             g_get_prgname());
 
 #define DEF(option, opt_arg, opt_enum, opt_help, arch_mask)    \
-    if ((arch_mask) & arch_type)                               \
+    if (qemu_arch_available(arch_mask)) \
         fputs(opt_help, stdout);
 
 #define ARCHHEADING(text, arch_mask) \
-    if ((arch_mask) & arch_type)    \
+    if (qemu_arch_available(arch_mask)) \
         puts(stringify(text));
 
 #define DEFHEADING(text) ARCHHEADING(text, QEMU_ARCH_ALL)
@@ -2929,7 +2929,7 @@ void qemu_init(int argc, char **argv)
             const QEMUOption *popt;
 
             popt = lookup_opt(argc, argv, &optarg, &optind);
-            if (!(popt->arch_mask & arch_type)) {
+            if (!qemu_arch_available(popt->arch_mask)) {
                 error_report("Option not supported for this target");
                 exit(1);
             }