Kernel: Add PageTable::Flags::CacheDisable

Also fix multiple places where we were using uint8_t as page table
flags instead of PageTable::flags_t which we promoted to uint16_t
while back.

kernel/arch/x86_64/PageTable.cpp

@@ -48,7 +48,22 @@ namespace Kernel
 
 	static inline PageTable::flags_t parse_flags(uint64_t entry)
 	{
-		return (s_has_nxe && !(entry & (1ull << 63)) ? PageTable::Flags::Execute : 0) | (entry & 0b100000111);
+		using Flags = PageTable::Flags;
+
+		PageTable::flags_t result = 0;
+		if (s_has_nxe && !(entry & (1ull << 63)))
+			result |= Flags::Execute;
+		if (entry & Flags::Reserved)
+			result |= Flags::Reserved;
+		if (entry & Flags::CacheDisable)
+			result |= Flags::CacheDisable;
+		if (entry & Flags::UserSupervisor)
+			result |= Flags::UserSupervisor;
+		if (entry & Flags::ReadWrite)
+			result |= Flags::ReadWrite;
+		if (entry & Flags::Present)
+			result |= Flags::Present;
+		return result;
 	}
 
 	void PageTable::initialize()
@@ -258,12 +273,14 @@ namespace Kernel
 		uint64_t pte   = (uc_vaddr >> 12) & 0x1FF;
 
 		uint64_t extra_flags = 0;
+		if (s_has_pge && pml4e == 511) // Map kernel memory as global
+			extra_flags |= 1ull << 8;
 		if (s_has_nxe && !(flags & Flags::Execute))
 			extra_flags |= 1ull << 63;
-		if (s_has_pge && pml4e == 511)
-			extra_flags |= 1ull << 8;
 		if (flags & Flags::Reserved)
 			extra_flags |= Flags::Reserved;
+		if (flags & Flags::CacheDisable)
+			extra_flags |= Flags::CacheDisable;
 
 		// NOTE: we add present here, since it has to be available in higher level structures
 		flags_t uwr_flags = (flags & (Flags::UserSupervisor | Flags::ReadWrite)) | Flags::Present;

kernel/include/kernel/Memory/PageTable.h

@@ -13,12 +13,13 @@ namespace Kernel
 		using flags_t = uint16_t;
 		enum Flags : flags_t 
 		{
-			Present = 1,
-			ReadWrite = 2,
-			UserSupervisor = 4,
-			Execute = 8,
-			Reserved = 256,
+			Present			= (1 << 0),
+			ReadWrite		= (1 << 1),
+			UserSupervisor	= (1 << 2),
+			CacheDisable	= (1 << 4),
+			Reserved		= (1 << 9),
 
+			Execute			= (1 << 15),
 			Used = Present | Reserved,
 		};
 

kernel/include/kernel/Memory/VirtualRange.h

@@ -15,9 +15,9 @@ namespace Kernel
 
 	public:
 		// Create virtual range to fixed virtual address
-		static BAN::ErrorOr<BAN::UniqPtr<VirtualRange>> create_to_vaddr(PageTable&, vaddr_t, size_t, uint8_t flags);
+		static BAN::ErrorOr<BAN::UniqPtr<VirtualRange>> create_to_vaddr(PageTable&, vaddr_t, size_t, PageTable::flags_t flags);
 		// Create virtual range to virtual address range
-		static BAN::ErrorOr<BAN::UniqPtr<VirtualRange>> create_to_vaddr_range(PageTable&, vaddr_t vaddr_start, vaddr_t vaddr_end, size_t, uint8_t flags);
+		static BAN::ErrorOr<BAN::UniqPtr<VirtualRange>> create_to_vaddr_range(PageTable&, vaddr_t vaddr_start, vaddr_t vaddr_end, size_t, PageTable::flags_t flags);
 		// Create virtual range in kernel memory with kmalloc
 		static BAN::ErrorOr<BAN::UniqPtr<VirtualRange>> create_kmalloc(size_t);
 		~VirtualRange();
@@ -26,7 +26,7 @@ namespace Kernel
 
 		vaddr_t vaddr() const { return m_vaddr; }
 		size_t size() const { return m_size; }
-		uint8_t flags() const { return m_flags; }
+		PageTable::flags_t flags() const { return m_flags; }
 
 		void set_zero();
 		void copy_from(size_t offset, const uint8_t* buffer, size_t bytes);
@@ -39,7 +39,7 @@ namespace Kernel
 		bool					m_kmalloc { false };
 		vaddr_t					m_vaddr { 0 };
 		size_t					m_size { 0 };
-		uint8_t					m_flags { 0 };
+		PageTable::flags_t		m_flags { 0 };
 		BAN::Vector<paddr_t>	m_physical_pages;
 	};
 

kernel/kernel/Memory/FixedWidthAllocator.cpp

@@ -263,7 +263,7 @@ namespace Kernel
 
 			vaddr_t vaddr = address_of_node(node);
 			vaddr_t page_begin = vaddr & PAGE_ADDR_MASK;
-			uint8_t flags = m_page_table.get_page_flags(page_begin);
+			PageTable::flags_t flags = m_page_table.get_page_flags(page_begin);
 
 			// Allocate and copy all data from this allocation to the new one
 			if (allocator->allocate_page_if_needed(page_begin, flags))

kernel/kernel/Memory/GeneralAllocator.cpp

@@ -97,7 +97,7 @@ namespace Kernel
 			new_allocation.address = allocation.address;
 			MUST(new_allocation.pages.reserve(allocation.pages.size()));
 
-			uint8_t flags = m_page_table.get_page_flags(allocation.address);
+			PageTable::flags_t flags = m_page_table.get_page_flags(allocation.address);
 			for (size_t i = 0; i < allocation.pages.size(); i++)
 			{
 				paddr_t paddr = Heap::get().take_free_page();

kernel/kernel/Memory/VirtualRange.cpp

@@ -6,7 +6,7 @@
 namespace Kernel
 {
 
-	BAN::ErrorOr<BAN::UniqPtr<VirtualRange>> VirtualRange::create_to_vaddr(PageTable& page_table, vaddr_t vaddr, size_t size, uint8_t flags)
+	BAN::ErrorOr<BAN::UniqPtr<VirtualRange>> VirtualRange::create_to_vaddr(PageTable& page_table, vaddr_t vaddr, size_t size, PageTable::flags_t flags)
 	{
 		ASSERT(size % PAGE_SIZE == 0);
 		ASSERT(vaddr % PAGE_SIZE == 0);
@@ -45,7 +45,7 @@ namespace Kernel
 		return result;
 	}
 
-	BAN::ErrorOr<BAN::UniqPtr<VirtualRange>> VirtualRange::create_to_vaddr_range(PageTable& page_table, vaddr_t vaddr_start, vaddr_t vaddr_end, size_t size, uint8_t flags)
+	BAN::ErrorOr<BAN::UniqPtr<VirtualRange>> VirtualRange::create_to_vaddr_range(PageTable& page_table, vaddr_t vaddr_start, vaddr_t vaddr_end, size_t size, PageTable::flags_t flags)
 	{
 		ASSERT(size % PAGE_SIZE == 0);
 		ASSERT(vaddr_start > 0);

kernel/kernel/Process.cpp

@@ -499,7 +499,7 @@ namespace Kernel
 				break;
 			case LibELF::PT_LOAD:
 			{
-				uint8_t flags = PageTable::Flags::UserSupervisor | PageTable::Flags::Present;
+				PageTable::flags_t flags = PageTable::Flags::UserSupervisor | PageTable::Flags::Present;
 				if (elf_program_header.p_flags & LibELF::PF_W)
 					flags |= PageTable::Flags::ReadWrite;
 				if (elf_program_header.p_flags & LibELF::PF_X)