From 6433798f06edecb464bf46dcca76cc308af90e52 Mon Sep 17 00:00:00 2001
From: TuxSH <1922548+TuxSH@users.noreply.github.com>
Date: Wed, 13 May 2020 19:01:56 +0100
Subject: [PATCH] Revamp mappableAlloc

---
 libctru/include/3ds/allocator/mappable.h | 27 +++++-----
 libctru/source/allocator/mappable.c      | 59 +++++++++++++++++++++
 libctru/source/allocator/mappable.cpp    | 67 ------------------------
 libctru/source/system/allocateHeaps.c    |  5 +-
 4 files changed, 75 insertions(+), 83 deletions(-)
 create mode 100644 libctru/source/allocator/mappable.c
 delete mode 100644 libctru/source/allocator/mappable.cpp

diff --git a/libctru/include/3ds/allocator/mappable.h b/libctru/include/3ds/allocator/mappable.h
index 6fabe93..fb57dc1 100644
--- a/libctru/include/3ds/allocator/mappable.h
+++ b/libctru/include/3ds/allocator/mappable.h
@@ -4,27 +4,24 @@
  */
 #pragma once
 
+#include <3ds/types.h>
+
 /**
- * @brief Reserves a mappable memory area.
- * @param size Size of the area to reserve.
+ * @brief Initializes the mappable allocator.
+ * @param addrMin Minimum address.
+ * @param addrMax Maxium address.
+ */
+void mappableInit(u32 addrMin, u32 addrMax);
+
+/**
+ * @brief Finds a mappable memory area.
+ * @param size Size of the area to find.
  * @return The mappable area.
  */
 void* mappableAlloc(size_t size);
 
 /**
- * @brief Retrieves the allocated size of a mappable area.
- * @return The size of the mappable area.
- */
-size_t mappableGetSize(void* mem);
-
-/**
- * @brief Frees a mappable area.
+ * @brief Frees a mappable area (stubbed).
  * @param mem Mappable area to free.
  */
 void mappableFree(void* mem);
-
-/**
- * @brief Gets the current mappable free space.
- * @return The current mappable free space.
- */
-u32 mappableSpaceFree(void);
diff --git a/libctru/source/allocator/mappable.c b/libctru/source/allocator/mappable.c
new file mode 100644
index 0000000..de770cf
--- /dev/null
+++ b/libctru/source/allocator/mappable.c
@@ -0,0 +1,59 @@
+#include <3ds/allocator/mappable.h>
+#include <3ds/svc.h>
+#include <3ds/result.h>
+
+static u32 minAddr, maxAddr, currentAddr;
+
+void mappableInit(u32 addrMin, u32 addrMax)
+{
+	minAddr = addrMin;
+	maxAddr = addrMax;
+	currentAddr = minAddr;
+}
+
+static u32 mappableFindAddressWithin(u32 start, u32 end, u32 size)
+{
+	MemInfo info;
+	PageInfo pgInfo;
+
+	u32 addr = start;
+	while (addr >= start && (addr + size) < end && (addr + size) >= addr)
+	{
+		if (R_FAILED(svcQueryMemory(&info, &pgInfo, addr)))
+			return 0;
+
+		if (info.state == MEMSTATE_FREE)
+		{
+			u32 sz = info.size - (addr - info.base_addr); // a free block might cover all the memory, etc.
+			if (sz >= size)
+				return addr;
+		}
+
+		addr = info.base_addr + info.size;
+	}
+
+	return 0;
+}
+
+void* mappableAlloc(size_t size)
+{
+	// Round up, can only allocate in page units
+	size = (size + 0xFFF) & ~0xFFF;
+
+	u32 addr = mappableFindAddressWithin(currentAddr, maxAddr, size);
+	if (addr == 0)
+	{
+		// Need to rollover (maybe)
+		addr = mappableFindAddressWithin(minAddr, currentAddr, size);
+		if (addr == 0)
+			return NULL;
+	}
+
+	currentAddr = addr + size >= maxAddr ? minAddr : addr + size;
+	return (void *)addr;
+}
+
+void mappableFree(void* mem)
+{
+	(void)mem;
+}
diff --git a/libctru/source/allocator/mappable.cpp b/libctru/source/allocator/mappable.cpp
deleted file mode 100644
index c75d7cd..0000000
--- a/libctru/source/allocator/mappable.cpp
+++ /dev/null
@@ -1,67 +0,0 @@
-extern "C"
-{
-	#include <3ds/types.h>
-	#include <3ds/allocator/mappable.h>
-	#include <3ds/util/rbtree.h>
-}
-
-#include "mem_pool.h"
-#include "addrmap.h"
-
-static MemPool sMappablePool;
-
-static bool mappableInit()
-{
-	auto blk = MemBlock::Create((u8*)0x10000000, 0x04000000);
-	if (blk)
-	{
-		sMappablePool.AddBlock(blk);
-		rbtree_init(&sAddrMap, addrMapNodeComparator);
-		return true;
-	}
-	return false;
-}
-
-void* mappableAlloc(size_t size)
-{
-	// Initialize the pool if it is not ready
-	if (!sMappablePool.Ready() && !mappableInit())
-		return nullptr;
-
-	// Allocate the chunk
-	MemChunk chunk;
-	if (!sMappablePool.Allocate(chunk, size, 12))
-		return nullptr;
-
-	auto node = newNode(chunk);
-	if (!node)
-	{
-		sMappablePool.Deallocate(chunk);
-		return nullptr;
-	}
-	if (rbtree_insert(&sAddrMap, &node->node));
-	return chunk.addr;
-}
-
-size_t mappableGetSize(void* mem)
-{
-	auto node = getNode(mem);
-	return node ? node->chunk.size : 0;
-}
-
-void mappableFree(void* mem)
-{
-	auto node = getNode(mem);
-	if (!node) return;
-
-	// Free the chunk
-	sMappablePool.Deallocate(node->chunk);
-
-	// Free the node
-	delNode(node);
-}
-
-u32 mappableSpaceFree()
-{
-	return sMappablePool.GetFreeSpace();
-}
diff --git a/libctru/source/system/allocateHeaps.c b/libctru/source/system/allocateHeaps.c
index fdb2ac8..d35b4d6 100644
--- a/libctru/source/system/allocateHeaps.c
+++ b/libctru/source/system/allocateHeaps.c
@@ -1,5 +1,5 @@
-#include <3ds/types.h>
 #include <3ds/svc.h>
+#include <3ds/allocator/mappable.h>
 #include <3ds/env.h>
 #include <3ds/os.h>
 
@@ -39,6 +39,9 @@ void __attribute__((weak)) __system_allocateHeaps(void) {
 	// Allocate the linear heap
 	svcControlMemory(&__ctru_linear_heap, 0x0, 0x0, __ctru_linear_heap_size, MEMOP_ALLOC_LINEAR, MEMPERM_READ | MEMPERM_WRITE);
 
+	// Mappable allocator init
+	mappableInit(0x10000000, 0x14000000);
+
 	// Set up newlib heap
 	fake_heap_start = (char*)__ctru_heap;
 	fake_heap_end = fake_heap_start + __ctru_heap_size;