rmm: Remove fallback impl of invalidate_all

It doesn't work on all non-x86 architectures.

rmm/src/arch/mod.rs

@@ -79,17 +79,9 @@ pub trait Arch: Clone + Copy {
     }
 
     unsafe fn invalidate(address: VirtualAddress);
-
-    #[inline(always)]
-    unsafe fn invalidate_all() {
-        unsafe {
-            //TODO: this stub only works on x86_64, maybe make the arch implement this?
-            Self::set_table(TableKind::User, Self::table(TableKind::User));
-        }
-    }
+    unsafe fn invalidate_all();
 
     unsafe fn table(table_kind: TableKind) -> PhysicalAddress;
-
     unsafe fn set_table(table_kind: TableKind, address: PhysicalAddress);
 
     #[inline(always)]

rmm/src/arch/x86.rs

@@ -36,6 +36,11 @@ impl Arch for X86Arch {
         unsafe { asm!("invlpg [{0}]", in(reg) address.data()) };
     }
 
+    #[inline(always)]
+    unsafe fn invalidate_all() {
+        unsafe { Self::set_table(TableKind::User, Self::table(TableKind::User)) };
+    }
+
     #[inline(always)]
     unsafe fn table(_table_kind: TableKind) -> PhysicalAddress {
         let address: usize;

rmm/src/arch/x86_64.rs

@@ -35,6 +35,11 @@ impl Arch for X8664Arch {
         unsafe { asm!("invlpg [{0}]", in(reg) address.data()) };
     }
 
+    #[inline(always)]
+    unsafe fn invalidate_all() {
+        unsafe { Self::set_table(TableKind::User, Self::table(TableKind::User)) };
+    }
+
     #[inline(always)]
     unsafe fn table(_table_kind: TableKind) -> PhysicalAddress {
         let address: usize;