From 208ed712f42cfd277405a22663197dc1c5e84cfe Mon Sep 17 00:00:00 2001
From: Liam <byteslice@airmail.cc>
Date: Mon, 6 Jun 2022 12:56:01 -0400
Subject: core/debugger: memory breakpoint support

---
 src/core/memory.cpp | 79 ++++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 78 insertions(+), 1 deletion(-)

(limited to 'src/core/memory.cpp')

diff --git a/src/core/memory.cpp b/src/core/memory.cpp
index 7534de01e..584808d50 100644
--- a/src/core/memory.cpp
+++ b/src/core/memory.cpp
@@ -67,6 +67,16 @@ struct Memory::Impl {
         return system.DeviceMemory().GetPointer(paddr) + vaddr;
     }
 
+    [[nodiscard]] u8* GetPointerFromDebugMemory(VAddr vaddr) const {
+        const PAddr paddr{current_page_table->backing_addr[vaddr >> PAGE_BITS]};
+
+        if (paddr == 0) {
+            return {};
+        }
+
+        return system.DeviceMemory().GetPointer(paddr) + vaddr;
+    }
+
     u8 Read8(const VAddr addr) {
         return Read<u8>(addr);
     }
@@ -187,6 +197,12 @@ struct Memory::Impl {
                 on_memory(copy_amount, mem_ptr);
                 break;
             }
+            case Common::PageType::DebugMemory: {
+                DEBUG_ASSERT(pointer);
+                u8* const mem_ptr{GetPointerFromDebugMemory(current_vaddr)};
+                on_memory(copy_amount, mem_ptr);
+                break;
+            }
             case Common::PageType::RasterizerCachedMemory: {
                 u8* const host_ptr{GetPointerFromRasterizerCachedMemory(current_vaddr)};
                 on_rasterizer(current_vaddr, copy_amount, host_ptr);
@@ -316,6 +332,58 @@ struct Memory::Impl {
             });
     }
 
+    void MarkRegionDebug(VAddr vaddr, u64 size, bool debug) {
+        if (vaddr == 0) {
+            return;
+        }
+
+        // Iterate over a contiguous CPU address space, marking/unmarking the region.
+        // The region is at a granularity of CPU pages.
+
+        const u64 num_pages = ((vaddr + size - 1) >> PAGE_BITS) - (vaddr >> PAGE_BITS) + 1;
+        for (u64 i = 0; i < num_pages; ++i, vaddr += PAGE_SIZE) {
+            const Common::PageType page_type{
+                current_page_table->pointers[vaddr >> PAGE_BITS].Type()};
+            if (debug) {
+                // Switch page type to debug if now debug
+                switch (page_type) {
+                case Common::PageType::Unmapped:
+                    ASSERT_MSG(false, "Attempted to mark unmapped pages as debug");
+                    break;
+                case Common::PageType::RasterizerCachedMemory:
+                case Common::PageType::DebugMemory:
+                    // Page is already marked.
+                    break;
+                case Common::PageType::Memory:
+                    current_page_table->pointers[vaddr >> PAGE_BITS].Store(
+                        nullptr, Common::PageType::DebugMemory);
+                    break;
+                default:
+                    UNREACHABLE();
+                }
+            } else {
+                // Switch page type to non-debug if now non-debug
+                switch (page_type) {
+                case Common::PageType::Unmapped:
+                    ASSERT_MSG(false, "Attempted to mark unmapped pages as non-debug");
+                    break;
+                case Common::PageType::RasterizerCachedMemory:
+                case Common::PageType::Memory:
+                    // Don't mess with already non-debug or rasterizer memory.
+                    break;
+                case Common::PageType::DebugMemory: {
+                    u8* const pointer{GetPointerFromDebugMemory(vaddr & ~PAGE_MASK)};
+                    current_page_table->pointers[vaddr >> PAGE_BITS].Store(
+                        pointer - (vaddr & ~PAGE_MASK), Common::PageType::Memory);
+                    break;
+                }
+                default:
+                    UNREACHABLE();
+                }
+            }
+        }
+    }
+
     void RasterizerMarkRegionCached(VAddr vaddr, u64 size, bool cached) {
         if (vaddr == 0) {
             return;
@@ -342,6 +410,7 @@ struct Memory::Impl {
                     // It is not necessary for a process to have this region mapped into its address
                     // space, for example, a system module need not have a VRAM mapping.
                     break;
+                case Common::PageType::DebugMemory:
                 case Common::PageType::Memory:
                     current_page_table->pointers[vaddr >> PAGE_BITS].Store(
                         nullptr, Common::PageType::RasterizerCachedMemory);
@@ -360,6 +429,7 @@ struct Memory::Impl {
                     // It is not necessary for a process to have this region mapped into its address
                     // space, for example, a system module need not have a VRAM mapping.
                     break;
+                case Common::PageType::DebugMemory:
                 case Common::PageType::Memory:
                     // There can be more than one GPU region mapped per CPU region, so it's common
                     // that this area is already unmarked as cached.
@@ -460,6 +530,8 @@ struct Memory::Impl {
         case Common::PageType::Memory:
             ASSERT_MSG(false, "Mapped memory page without a pointer @ 0x{:016X}", vaddr);
             return nullptr;
+        case Common::PageType::DebugMemory:
+            return GetPointerFromDebugMemory(vaddr);
         case Common::PageType::RasterizerCachedMemory: {
             u8* const host_ptr{GetPointerFromRasterizerCachedMemory(vaddr)};
             on_rasterizer();
@@ -591,7 +663,8 @@ bool Memory::IsValidVirtualAddress(const VAddr vaddr) const {
         return false;
     }
     const auto [pointer, type] = page_table.pointers[page].PointerType();
-    return pointer != nullptr || type == Common::PageType::RasterizerCachedMemory;
+    return pointer != nullptr || type == Common::PageType::RasterizerCachedMemory ||
+           type == Common::PageType::DebugMemory;
 }
 
 bool Memory::IsValidVirtualAddressRange(VAddr base, u64 size) const {
@@ -707,4 +780,8 @@ void Memory::RasterizerMarkRegionCached(VAddr vaddr, u64 size, bool cached) {
     impl->RasterizerMarkRegionCached(vaddr, size, cached);
 }
 
+void Memory::MarkRegionDebug(VAddr vaddr, u64 size, bool debug) {
+    impl->MarkRegionDebug(vaddr, size, debug);
+}
+
 } // namespace Core::Memory
-- 
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