[port/freebsd] enable Libusb by default on FBSD15

CMakeLists.txt

@@ -174,8 +174,8 @@ if ((MSVC AND NOT (CMAKE_BUILD_TYPE MATCHES "Debug|RelWithDebInfo") OR ANDROID))
 endif()
 option(YUZU_USE_BUNDLED_SIRIT "Download bundled sirit" ${BUNDLED_SIRIT_DEFAULT})
 
-# Re-allow on FreeBSD once its on mainline ports
-cmake_dependent_option(ENABLE_LIBUSB "Enable the use of LibUSB" ON "WIN32 OR PLATFORM_LINUX OR APPLE" OFF)
+# FreeBSD 15+ has libusb, versions below should disable it
+cmake_dependent_option(ENABLE_LIBUSB "Enable the use of LibUSB" ON "WIN32 OR PLATFORM_LINUX OR PLATFORM_FREEBSD OR APPLE" OFF)
 
 cmake_dependent_option(ENABLE_OPENGL "Enable OpenGL" ON "NOT WIN32 OR NOT ARCHITECTURE_arm64" OFF)
 mark_as_advanced(FORCE ENABLE_OPENGL)

src/common/host_memory.cpp

@@ -219,6 +219,11 @@ public:
         }
     }
 
+    bool ClearBackingRegion(size_t physical_offset, size_t length) {
+        // TODO: This does not seem to be possible on Windows.
+        return false;
+    }
+
     void EnableDirectMappedAddress() {
         // TODO
         UNREACHABLE();
@@ -612,6 +617,24 @@ public:
         ASSERT_MSG(ret == 0, "mprotect failed: {}", strerror(errno));
     }
 
+    bool ClearBackingRegion(size_t physical_offset, size_t length) {
+#ifdef __linux__
+        // Only incur syscall cost IF memset would be slower (theshold = 16MiB)
+        // TODO(lizzie): Smarter way to dynamically get this threshold (broadwell != raptor lake) for example
+        if (length >= 2097152UL * 8) {
+            // Set MADV_REMOVE on backing map to destroy it instantly.
+            // This also deletes the area from the backing file.
+            int ret = madvise(backing_base + physical_offset, length, MADV_REMOVE);
+            ASSERT_MSG(ret == 0, "madvise failed: {}", strerror(errno));
+            return true;
+        } else {
+            return false;
+        }
+#else
+        return false;
+#endif
+    }
+
     void EnableDirectMappedAddress() {
         virtual_base = nullptr;
     }
@@ -739,7 +762,9 @@ void HostMemory::Protect(size_t virtual_offset, size_t length, MemoryPermission
 }
 
 void HostMemory::ClearBackingRegion(size_t physical_offset, size_t length, u32 fill_value) {
-    std::memset(backing_base + physical_offset, fill_value, length);
+    if (!impl || fill_value != 0 || !impl->ClearBackingRegion(physical_offset, length)) {
+        std::memset(backing_base + physical_offset, fill_value, length);
+    }
 }
 
 void HostMemory::EnableDirectMappedAddress() {