2 files changed, 46 insertions, 24 deletions

diff --git a/src/core/hle/kernel/vm_manager.cpp b/src/core/hle/kernel/vm_manager.cpp
index 523fe63e9..ec0a480ce 100644
--- a/src/core/hle/kernel/vm_manager.cpp
+++ b/src/core/hle/kernel/vm_manager.cpp
@@ -274,14 +274,23 @@ ResultVal<VAddr> VMManager::SetHeapSize(u64 size) {
         UnmapRange(heap_region_base, GetCurrentHeapSize());
     }
 
-    // If necessary, expand backing vector to cover new heap extents.
-    if (size > GetCurrentHeapSize()) {
-        const u64 alloc_size = size - GetCurrentHeapSize();
+    // If necessary, expand backing vector to cover new heap extents in
+    // the case of allocating. Otherwise, shrink the backing memory,
+    // if a smaller heap has been requested.
+    const u64 old_heap_size = GetCurrentHeapSize();
+    if (size > old_heap_size) {
+        const u64 alloc_size = size - old_heap_size;
 
         heap_memory->insert(heap_memory->end(), alloc_size, 0);
-        heap_end = heap_region_base + size;
+        RefreshMemoryBlockMappings(heap_memory.get());
+    } else if (size < old_heap_size) {
+        heap_memory->resize(size);
+        heap_memory->shrink_to_fit();
+
         RefreshMemoryBlockMappings(heap_memory.get());
     }
+
+    heap_end = heap_region_base + size;
     ASSERT(GetCurrentHeapSize() == heap_memory->size());
 
     const auto mapping_result =
@@ -293,23 +302,6 @@ ResultVal<VAddr> VMManager::SetHeapSize(u64 size) {
     return MakeResult<VAddr>(heap_region_base);
 }
 
-ResultCode VMManager::HeapFree(VAddr target, u64 size) {
-    if (!IsWithinHeapRegion(target, size)) {
-        return ERR_INVALID_ADDRESS;
-    }
-
-    if (size == 0) {
-        return RESULT_SUCCESS;
-    }
-
-    const ResultCode result = UnmapRange(target, size);
-    if (result.IsError()) {
-        return result;
-    }
-
-    return RESULT_SUCCESS;
-}
-
 MemoryInfo VMManager::QueryMemory(VAddr address) const {
     const auto vma = FindVMA(address);
     MemoryInfo memory_info{};
diff --git a/src/core/hle/kernel/vm_manager.h b/src/core/hle/kernel/vm_manager.h
index cab748364..6f484b7bf 100644
--- a/src/core/hle/kernel/vm_manager.h
+++ b/src/core/hle/kernel/vm_manager.h
@@ -380,11 +380,41 @@ public:
     /// Changes the permissions of a range of addresses, splitting VMAs as necessary.
     ResultCode ReprotectRange(VAddr target, u64 size, VMAPermission new_perms);
 
-    ResultVal<VAddr> SetHeapSize(u64 size);
-    ResultCode HeapFree(VAddr target, u64 size);
-
     ResultCode MirrorMemory(VAddr dst_addr, VAddr src_addr, u64 size, MemoryState state);
 
+    /// Attempts to allocate a heap with the given size.
+    ///
+    /// @param size The size of the heap to allocate in bytes.
+    ///
+    /// @note If a heap is currently allocated, and this is called
+    ///       with a size that is equal to the size of the current heap,
+    ///       then this function will do nothing and return the current
+    ///       heap's starting address, as there's no need to perform
+    ///       any additional heap allocation work.
+    ///
+    /// @note If a heap is currently allocated, and this is called
+    ///       with a size less than the current heap's size, then
+    ///       this function will attempt to shrink the heap.
+    ///
+    /// @note If a heap is currently allocated, and this is called
+    ///       with a size larger than the current heap's size, then
+    ///       this function will attempt to extend the size of the heap.
+    ///
+    /// @returns A result indicating either success or failure.
+    ///          <p>
+    ///          If successful, this function will return a result
+    ///          containing the starting address to the allocated heap.
+    ///          <p>
+    ///          If unsuccessful, this function will return a result
+    ///          containing an error code.
+    ///
+    /// @pre The given size must lie within the allowable heap
+    ///      memory region managed by this VMManager instance.
+    ///      Failure to abide by this will result in ERR_OUT_OF_MEMORY
+    ///      being returned as the result.
+    ///
+    ResultVal<VAddr> SetHeapSize(u64 size);
+
     /// Queries the memory manager for information about the given address.
     ///
     /// @param address The address to query the memory manager about for information.