Kernel: Move PAGE_MASK define to the shared CPU.h header

These are the same for both x86 and aarch64 for now. Also update some
include paths to use the generic CPU.h header.

Kernel/Arch/CPU.h

@@ -9,6 +9,13 @@
 
 #include <AK/Platform.h>
 
+#define PAGE_MASK (~(FlatPtr)0xfffu)
+
+#define LSW(x) ((u32)(x)&0xFFFF)
+#define MSW(x) (((u32)(x) >> 16) & 0xFFFF)
+#define LSB(x) ((x)&0xFF)
+#define MSB(x) (((x) >> 8) & 0xFF)
+
 #if ARCH(X86_64) || ARCH(I386)
 #    include <Kernel/Arch/x86/CPU.h>
 #elif ARCH(AARCH64)

Kernel/Arch/aarch64/CPU.h

@@ -6,8 +6,6 @@
 
 #pragma once
 
-#define PAGE_MASK (~(FlatPtr)0xfffu)
-
 namespace Kernel {
 
 void drop_to_exception_level_1();

Kernel/Arch/x86/CPU.h

@@ -18,7 +18,6 @@ VALIDATE_IS_X86()
 /* Map IRQ0-15 @ ISR 0x50-0x5F */
 #define IRQ_VECTOR_BASE 0x50
 #define GENERIC_INTERRUPT_HANDLERS_COUNT (256 - IRQ_VECTOR_BASE)
-#define PAGE_MASK (~(FlatPtr)0xfffu)
 
 namespace Kernel {
 
@@ -36,11 +35,6 @@ inline u32 get_iopl_from_eflags(u32 eflags)
 DescriptorTablePointer const& get_gdtr();
 DescriptorTablePointer const& get_idtr();
 
-#define LSW(x) ((u32)(x)&0xFFFF)
-#define MSW(x) (((u32)(x) >> 16) & 0xFFFF)
-#define LSB(x) ((x)&0xFF)
-#define MSB(x) (((x) >> 8) & 0xFF)
-
 constexpr FlatPtr page_base_of(FlatPtr address)
 {
     return address & PAGE_MASK;

Kernel/Arch/x86/RegisterState.h

@@ -9,8 +9,8 @@
 #include <AK/Types.h>
 #include <LibC/sys/arch/i386/regs.h>
 
+#include <Kernel/Arch/CPU.h>
 #include <Kernel/Arch/x86/ASM_wrapper.h>
-#include <Kernel/Arch/x86/CPU.h>
 
 #include <AK/Platform.h>
 VALIDATE_IS_X86()

Kernel/Arch/x86/VGA/IOArbiter.cpp

@@ -5,8 +5,8 @@
  */
 
 #include <AK/Try.h>
+#include <Kernel/Arch/CPU.h>
 #include <Kernel/Arch/Delay.h>
-#include <Kernel/Arch/x86/CPU.h>
 #include <Kernel/Arch/x86/IO.h>
 #include <Kernel/Arch/x86/VGA/IOArbiter.h>
 

Kernel/Arch/x86/common/CPU.cpp

@@ -5,7 +5,7 @@
  */
 
 #include <AK/Assertions.h>
-#include <Kernel/Arch/x86/CPU.h>
+#include <Kernel/Arch/CPU.h>
 #include <Kernel/Panic.h>
 #include <Kernel/Process.h>