Expose page table to dynarmic for optimized reads and writes to the JIT

src/core/arm/dynarmic/arm_dynarmic.cpp

@@ -52,6 +52,7 @@ static Dynarmic::UserCallbacks GetUserCallbacks(ARMul_State* interpeter_state) {
     user_callbacks.MemoryWrite16 = &Memory::Write16;
     user_callbacks.MemoryWrite32 = &Memory::Write32;
     user_callbacks.MemoryWrite64 = &Memory::Write64;
+    user_callbacks.page_table = Memory::GetCurrentPageTablePointers();
     return user_callbacks;
 }
 

src/core/memory.cpp

@@ -45,13 +45,11 @@ struct SpecialRegion {
  * requires an indexed fetch and a check for NULL.
  */
 struct PageTable {
-    static const size_t NUM_ENTRIES = 1 << (32 - PAGE_BITS);
-
     /**
      * Array of memory pointers backing each page. An entry can only be non-null if the
      * corresponding entry in the `attributes` array is of type `Memory`.
      */
-    std::array<u8*, NUM_ENTRIES> pointers;
+    std::array<u8*, PAGE_TABLE_NUM_ENTRIES> pointers;
 
     /**
      * Contains MMIO handlers that back memory regions whose entries in the `attribute` array is of
@@ -63,13 +61,13 @@ struct PageTable {
      * Array of fine grained page attributes. If it is set to any value other than `Memory`, then
      * the corresponding entry in `pointers` MUST be set to null.
      */
-    std::array<PageType, NUM_ENTRIES> attributes;
+    std::array<PageType, PAGE_TABLE_NUM_ENTRIES> attributes;
 
     /**
      * Indicates the number of externally cached resources touching a page that should be
      * flushed before the memory is accessed
      */
-    std::array<u8, NUM_ENTRIES> cached_res_count;
+    std::array<u8, PAGE_TABLE_NUM_ENTRIES> cached_res_count;
 };
 
 /// Singular page table used for the singleton process
@@ -77,6 +75,10 @@ static PageTable main_page_table;
 /// Currently active page table
 static PageTable* current_page_table = &main_page_table;
 
+std::array<u8*, PAGE_TABLE_NUM_ENTRIES>* GetCurrentPageTablePointers() {
+    return &current_page_table->pointers;
+}
+
 static void MapPages(u32 base, u32 size, u8* memory, PageType type) {
     LOG_DEBUG(HW_Memory, "Mapping %p onto %08X-%08X", memory, base * PAGE_SIZE,
               (base + size) * PAGE_SIZE);
@@ -84,7 +86,7 @@ static void MapPages(u32 base, u32 size, u8* memory, PageType type) {
     u32 end = base + size;
 
     while (base != end) {
-        ASSERT_MSG(base < PageTable::NUM_ENTRIES, "out of range mapping at %08X", base);
+        ASSERT_MSG(base < PAGE_TABLE_NUM_ENTRIES, "out of range mapping at %08X", base);
 
         // Since pages are unmapped on shutdown after video core is shutdown, the renderer may be
         // null here

src/core/memory.h

@@ -4,6 +4,7 @@
 
 #pragma once
 
+#include <array>
 #include <cstddef>
 #include <string>
 #include "common/common_types.h"
@@ -17,6 +18,7 @@ namespace Memory {
 const u32 PAGE_SIZE = 0x1000;
 const u32 PAGE_MASK = PAGE_SIZE - 1;
 const int PAGE_BITS = 12;
+const size_t PAGE_TABLE_NUM_ENTRIES = 1 << (32 - PAGE_BITS);
 
 /// Physical memory regions as seen from the ARM11
 enum : PAddr {
@@ -166,4 +168,11 @@ void RasterizerFlushRegion(PAddr start, u32 size);
  * Flushes and invalidates any externally cached rasterizer resources touching the given region.
  */
 void RasterizerFlushAndInvalidateRegion(PAddr start, u32 size);
+
+/**
+ * Dynarmic has an optimization to memory accesses when the pointer to the page exists that
+ * can be used by setting up the current page table as a callback. This function is used to
+ * retrieve the current page table for that purpose.
+ */
+std::array<u8*, PAGE_TABLE_NUM_ENTRIES>* GetCurrentPageTablePointers();
 }