WIP: Remove SYS_CLONE (to be done in userspace).

src/arch/x86_64/interrupt/syscall.rs

@@ -160,23 +160,3 @@ interrupt_stack!(syscall, |stack| {
         syscall::syscall(scratch.rax, stack.preserved.rbx, scratch.rcx, scratch.rdx, scratch.rsi, scratch.rdi, rbp, stack)
     })
 });
-
-#[naked]
-pub unsafe extern "C" fn clone_ret() {
-    core::arch::asm!(concat!(
-    // The address of this instruction is injected by `clone` in process.rs, on
-    // top of the stack syscall->inner in this file, which is done using the rbp
-    // register we save there.
-    //
-    // The top of our stack here is the address pointed to by rbp, which is:
-    //
-    // - the previous rbp
-    // - the return location
-    //
-    // Our goal is to return from the parent function, inner, so we restore
-    // rbp...
-    "pop rbp\n",
-    // ...and we return to the address at the top of the stack
-    "ret\n",
-    ), options(noreturn));
-}

src/arch/x86_64/paging/mapper.rs

@@ -1,13 +1,15 @@
 use super::{linear_phys_to_virt, Page, PAGE_SIZE, PageFlags, PhysicalAddress, VirtualAddress};
+
+use crate::ipi::{ipi, IpiKind, IpiTarget};
 use crate::memory::{allocate_frames, deallocate_frames, Enomem, Frame};
 
 use super::RmmA;
 use super::table::{Table, Level4};
 
-pub use rmm::{PageFlush, PageFlushAll};
+pub use rmm::{Flusher, PageFlush, PageFlushAll};
 
 pub struct Mapper<'table> {
-    p4: &'table mut Table<Level4>,
+    pub(in super) p4: &'table mut Table<Level4>,
 }
 
 impl core::fmt::Debug for Mapper<'_> {
@@ -192,3 +194,21 @@ impl<'table> Mapper<'table> {
             .map(|frame| PhysicalAddress::new(frame.start_address().data() + offset))
     }
 }
+
+pub struct InactiveFlusher { _inner: () }
+impl InactiveFlusher {
+    // TODO: cpu id
+    pub fn new() -> Self { Self { _inner: () } }
+}
+
+impl Flusher<RmmA> for InactiveFlusher {
+    fn consume(&mut self, flush: PageFlush<RmmA>) {
+        // TODO: Push to TLB "mailbox" or tell it to reload CR3 if there are too many entries.
+        unsafe { flush.ignore(); }
+    }
+}
+impl Drop for InactiveFlusher {
+    fn drop(&mut self) {
+        ipi(IpiKind::Tlb, IpiTarget::Other);
+    }
+}

src/arch/x86_64/paging/mod.rs

@@ -14,6 +14,7 @@ use self::table::{Level4, Table};
 
 pub use rmm::{
     Arch as RmmArch,
+    Flusher,
     PageFlags,
     PhysicalAddress,
     TableKind,
@@ -112,7 +113,7 @@ unsafe fn map_percpu(cpu_id: usize, mapper: &mut Mapper) -> PageFlushAll<RmmA> {
     let start = crate::KERNEL_PERCPU_OFFSET + crate::KERNEL_PERCPU_SIZE * cpu_id;
     let end = start + size;
 
-    let flush_all = PageFlushAll::new();
+    let mut flush_all = PageFlushAll::new();
     let start_page = Page::containing_address(VirtualAddress::new(start));
     let end_page = Page::containing_address(VirtualAddress::new(end - 1));
     for page in Page::range_inclusive(start_page, end_page) {
@@ -288,6 +289,11 @@ impl ActivePageTable {
     pub unsafe fn address(&self) -> usize {
         RmmA::table().data()
     }
+    pub fn mapper<'a>(&'a mut self) -> Mapper<'a> {
+        Mapper {
+            p4: self.p4,
+        }
+    }
 }
 
 impl Drop for ActivePageTable {