Kernel: Make MemoryManager compile on aarch64

Author: https://github.com/jamesmintram
Commit: https://github.com/SerenityOS/serenity/commit/d79c772c87
Pull-request: https://github.com/SerenityOS/serenity/pull/13447

Kernel/Arch/aarch64/CrashHandler.cpp

@@ -4,6 +4,8 @@
  * SPDX-License-Identifier: BSD-2-Clause
  */
 
+#include <AK/Forward.h>
+
 #include <Kernel/Arch/CPU.h>
 #include <Kernel/Arch/RegisterState.h>
 

Kernel/Arch/aarch64/PageDirectory.cpp

@@ -0,0 +1,33 @@
+/*
+ * Copyright (c) 2018-2021, Andreas Kling <kling@serenityos.org>
+ * Copyright (c) 2018-2022, James Mintram <me@jamesrm.com>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <Kernel/Memory/PageDirectory.h>
+
+namespace Kernel::Memory {
+
+void PageDirectory::register_page_directory(PageDirectory*)
+{
+}
+
+void PageDirectory::deregister_page_directory(PageDirectory*)
+{
+}
+
+RefPtr<PageDirectory> PageDirectory::find_current()
+{
+    return nullptr;
+}
+
+void activate_kernel_page_directory(PageDirectory const&)
+{
+}
+
+void activate_page_directory(PageDirectory const&, Thread*)
+{
+}
+
+}

Kernel/Arch/aarch64/Processor.h

@@ -13,8 +13,14 @@
 
 #include <Kernel/Arch/ProcessorSpecificDataID.h>
 
+class VirtualAddress;
+
 namespace Kernel {
 
+namespace Memory {
+class PageDirectory;
+};
+
 class Thread;
 
 // FIXME This needs to go behind some sort of platform abstraction
@@ -41,6 +47,14 @@ public:
         return false;
     }
 
+    ALWAYS_INLINE static void flush_tlb_local(VirtualAddress&, size_t&)
+    {
+    }
+
+    ALWAYS_INLINE static void flush_tlb(Memory::PageDirectory const*, VirtualAddress const&, size_t)
+    {
+    }
+
     ALWAYS_INLINE static u32 current_id()
     {
         return 0;

Kernel/Arch/aarch64/RegisterState.h

@@ -9,6 +9,8 @@
 namespace Kernel {
 
 struct RegisterState {
+    FlatPtr userspace_sp() const { return 0; }
+    FlatPtr ip() const { return 0; }
 };
 
 struct DebugRegisterState {

Kernel/Arch/x86/common/PageDirectory.cpp

@@ -0,0 +1,50 @@
+/*
+ * Copyright (c) 2018-2021, Andreas Kling <kling@serenityos.org>
+ * Copyright (c) 2018-2022, James Mintram <me@jamesrm.com>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <AK/Singleton.h>
+
+#include <Kernel/Memory/PageDirectory.h>
+#include <Kernel/Thread.h>
+
+namespace Kernel::Memory {
+
+static Singleton<IntrusiveRedBlackTree<&PageDirectory::m_tree_node>> s_cr3_map;
+
+static IntrusiveRedBlackTree<&PageDirectory::m_tree_node>& cr3_map()
+{
+    VERIFY_INTERRUPTS_DISABLED();
+    return *s_cr3_map;
+}
+
+void PageDirectory::register_page_directory(PageDirectory* directory)
+{
+    cr3_map().insert(directory->cr3(), *directory);
+}
+
+void PageDirectory::deregister_page_directory(PageDirectory* directory)
+{
+    cr3_map().remove(directory->cr3());
+}
+
+RefPtr<PageDirectory> PageDirectory::find_current()
+{
+    SpinlockLocker lock(s_mm_lock);
+    return cr3_map().find(read_cr3());
+}
+
+void activate_kernel_page_directory(PageDirectory const& pgd)
+{
+    write_cr3(pgd.cr3());
+}
+
+void activate_page_directory(PageDirectory const& pgd, Thread* current_thread)
+{
+    current_thread->regs().cr3 = pgd.cr3();
+    write_cr3(pgd.cr3());
+}
+
+}

Kernel/CMakeLists.txt

@@ -326,6 +326,7 @@ if ("${SERENITY_ARCH}" STREQUAL "i686" OR "${SERENITY_ARCH}" STREQUAL "x86_64")
         ${CMAKE_CURRENT_SOURCE_DIR}/Arch/x86/common/CPU.cpp
         ${CMAKE_CURRENT_SOURCE_DIR}/Arch/x86/common/CPUID.cpp
         ${CMAKE_CURRENT_SOURCE_DIR}/Arch/x86/common/Interrupts.cpp
+        ${CMAKE_CURRENT_SOURCE_DIR}/Arch/x86/common/PageDirectory.cpp
         ${CMAKE_CURRENT_SOURCE_DIR}/Arch/x86/common/Processor.cpp
         ${CMAKE_CURRENT_SOURCE_DIR}/Arch/x86/common/ProcessorInfo.cpp
         ${CMAKE_CURRENT_SOURCE_DIR}/Arch/x86/common/SafeMem.cpp
@@ -396,6 +397,7 @@ else()
         Arch/aarch64/Mailbox.cpp
         Arch/aarch64/MainIdRegister.cpp
         Arch/aarch64/MMIO.cpp
+        Arch/aarch64/PageDirectory.cpp
         Arch/aarch64/Timer.cpp
         Arch/aarch64/UART.cpp
         Arch/aarch64/Utils.cpp

Kernel/Memory/MemoryManager.cpp

@@ -8,7 +8,9 @@
 #include <AK/Memory.h>
 #include <AK/StringView.h>
 #include <Kernel/Arch/CPU.h>
+#include <Kernel/Arch/PageDirectory.h>
 #include <Kernel/Arch/PageFault.h>
+#include <Kernel/Arch/RegisterState.h>
 #include <Kernel/BootInfo.h>
 #include <Kernel/CMOS.h>
 #include <Kernel/FileSystem/Inode.h>
@@ -78,7 +80,7 @@ UNMAP_AFTER_INIT MemoryManager::MemoryManager()
 
     SpinlockLocker lock(s_mm_lock);
     parse_memory_map();
-    write_cr3(kernel_page_directory().cr3());
+    activate_kernel_page_directory(kernel_page_directory());
     protect_kernel_image();
 
     // We're temporarily "committing" to two pages that we need to allocate below
@@ -105,7 +107,7 @@ UNMAP_AFTER_INIT void MemoryManager::protect_kernel_image()
         auto& pte = *ensure_pte(kernel_page_directory(), VirtualAddress(i));
         pte.set_writable(false);
     }
-    if (Processor::current().has_feature(CPUFeature::NX)) {
+    if (Processor::current().has_nx()) {
         // Disable execution of the kernel data, bss and heap segments.
         for (auto const* i = start_of_kernel_data; i < end_of_kernel_image; i += PAGE_SIZE) {
             auto& pte = *ensure_pte(kernel_page_directory(), VirtualAddress(i));
@@ -467,7 +469,7 @@ UNMAP_AFTER_INIT void MemoryManager::initialize_physical_pages()
             pte.set_physical_page_base(physical_page_array_current_page);
             pte.set_user_allowed(false);
             pte.set_writable(true);
-            if (Processor::current().has_feature(CPUFeature::NX))
+            if (Processor::current().has_nx())
                 pte.set_execute_disabled(false);
             pte.set_global(true);
             pte.set_present(true);
@@ -710,7 +712,7 @@ Region* MemoryManager::find_region_from_vaddr(VirtualAddress vaddr)
 {
     if (auto* region = kernel_region_from_vaddr(vaddr))
         return region;
-    auto page_directory = PageDirectory::find_by_cr3(read_cr3());
+    auto page_directory = PageDirectory::find_current();
     if (!page_directory)
         return nullptr;
     VERIFY(page_directory->address_space());
@@ -1024,7 +1026,7 @@ void MemoryManager::enter_address_space(AddressSpace& space)
     SpinlockLocker lock(s_mm_lock);
 
     current_thread->regs().cr3 = space.page_directory().cr3();
-    write_cr3(space.page_directory().cr3());
+    activate_page_directory(space.page_directory(), current_thread);
 }
 
 void MemoryManager::flush_tlb_local(VirtualAddress vaddr, size_t page_count)

Kernel/Memory/MemoryManager.h

@@ -22,6 +22,7 @@
 
 namespace Kernel {
 class PageDirectoryEntry;
+class PageTableEntry;
 }
 
 struct KmallocGlobalData;

Kernel/Memory/PageDirectory.cpp

@@ -20,20 +20,6 @@ extern u8 end_of_kernel_image[];
 
 namespace Kernel::Memory {
 
-static Singleton<IntrusiveRedBlackTree<&PageDirectory::m_tree_node>> s_cr3_map;
-
-static IntrusiveRedBlackTree<&PageDirectory::m_tree_node>& cr3_map()
-{
-    VERIFY_INTERRUPTS_DISABLED();
-    return *s_cr3_map;
-}
-
-RefPtr<PageDirectory> PageDirectory::find_by_cr3(FlatPtr cr3)
-{
-    SpinlockLocker lock(s_mm_lock);
-    return cr3_map().find(cr3);
-}
-
 UNMAP_AFTER_INIT NonnullRefPtr<PageDirectory> PageDirectory::must_create_kernel_page_directory()
 {
     auto directory = adopt_ref_if_nonnull(new (nothrow) PageDirectory).release_nonnull();
@@ -125,7 +111,7 @@ ErrorOr<NonnullRefPtr<PageDirectory>> PageDirectory::try_create_for_userspace(Vi
         MM.unquickmap_page();
     }
 
-    cr3_map().insert(directory->cr3(), directory);
+    register_page_directory(directory);
     return directory;
 }
 
@@ -150,7 +136,7 @@ PageDirectory::~PageDirectory()
 {
     if (is_cr3_initialized()) {
         SpinlockLocker lock(s_mm_lock);
-        cr3_map().remove(cr3());
+        deregister_page_directory(this);
     }
 }
 

Kernel/Memory/PageDirectory.h

@@ -23,7 +23,7 @@ class PageDirectory : public RefCounted<PageDirectory> {
 public:
     static ErrorOr<NonnullRefPtr<PageDirectory>> try_create_for_userspace(VirtualRangeAllocator const* parent_range_allocator = nullptr);
     static NonnullRefPtr<PageDirectory> must_create_kernel_page_directory();
-    static RefPtr<PageDirectory> find_by_cr3(FlatPtr);
+    static RefPtr<PageDirectory> find_current();
 
     ~PageDirectory();
 
@@ -62,6 +62,8 @@ public:
 
 private:
     PageDirectory();
+    static void register_page_directory(PageDirectory* directory);
+    static void deregister_page_directory(PageDirectory* directory);
 
     AddressSpace* m_space { nullptr };
     VirtualRangeAllocator m_range_allocator;
@@ -77,4 +79,7 @@ private:
     RecursiveSpinlock m_lock;
 };
 
+void activate_kernel_page_directory(PageDirectory const& pgd);
+void activate_page_directory(PageDirectory const& pgd, Thread* current_thread);
+
 }