[settings] Disable fastmem on Linux systems with non-4kb page sizes

Asahi, etc

Signed-off-by: crueter <crueter@eden-emu.dev>

src/common/settings.cpp

@@ -27,6 +27,10 @@
 #include "common/settings.h"
 #include "common/time_zone.h"
 
+#ifdef __linux__
+#include <unistd.h>
+#endif
+
 namespace Settings {
 
 // Clang 14 and earlier have errors when explicitly instantiating these classes
@@ -178,7 +182,10 @@ bool IsFastmemEnabled() {
         return bool(values.cpuopt_fastmem);
     else if (values.cpu_accuracy.GetValue() == CpuAccuracy::Unsafe)
         return bool(values.cpuopt_unsafe_host_mmu);
-#if !defined(__APPLE__) && !defined(__linux__) && !defined(__ANDROID__) && !defined(_WIN32)
+#if defined(__linux__)
+    // Only 4kb systems support host MMU right now
+    return getpagesize() == 4096;
+#elif !defined(__APPLE__) && !defined(__ANDROID__) && !defined(_WIN32)
     return false;
 #else
     return true;