feat: implement configure_protection and map_shared with real page mapping, remove dead context_switch from Platform trait

crates/adapter-riscv/src/platform.rs

@@ -1,12 +1,11 @@
 use domain::memory::MemoryRegion;
 use domain::process::MAX_PROCESSES;
-use domain::thread::SavedContext;
 use platform::Platform;
 use types::{
     address::{EntryPoint, PhysicalAddress, StackPointer},
     bounded::PageCount,
     id::{CoreId, IrqId, ProcessId},
-    permission::PermissionSet,
+    permission::{Permission, PermissionSet},
     time::{Ticks, TimerDuration},
 };
 
@@ -30,23 +29,28 @@ impl RiscVPlatform {
     pub fn page_table_for(&self, pid: ProcessId) -> usize {
         self.page_tables[pid.raw() as usize]
     }
+
+    fn ensure_page_table(&mut self, pid: ProcessId) -> &mut mmu::PageTable {
+        let idx = pid.raw() as usize;
+        if self.page_tables[idx] == 0 {
+            let kernel_pt = unsafe { &*(self.page_tables[0] as *const mmu::PageTable) };
+            let user_pt = mmu::create_user_page_table(kernel_pt, 0, 0, 0x10000);
+            self.page_tables[idx] = user_pt as *const mmu::PageTable as usize;
+        }
+        unsafe { &mut *(self.page_tables[idx] as *mut mmu::PageTable) }
+    }
 }
 
 impl Platform for RiscVPlatform {
-    fn configure_protection(&mut self, process: ProcessId, _regions: &[MemoryRegion]) {
-        if self.page_tables[process.raw() as usize] == 0 {
-            let kernel_pt_addr = self.page_tables[0];
-            let kernel_pt = unsafe { &*(kernel_pt_addr as *const mmu::PageTable) };
-            let user_pt = mmu::create_user_page_table(kernel_pt, 0, 0, 0x10000);
-            self.page_tables[process.raw() as usize] = user_pt as *const mmu::PageTable as usize;
+    fn configure_protection(&mut self, process: ProcessId, regions: &[MemoryRegion]) {
+        let pt = self.ensure_page_table(process);
+        for region in regions {
+            let base_pa = region.base().raw();
+            let pages = region.size().value() as usize;
+            mmu::map_range(pt, base_pa, base_pa, pages, true, true, true, true, false);
         }
     }
 
-    fn context_switch(&mut self, from: &mut SavedContext, to: &SavedContext) {
-        let _ = from;
-        let _ = to;
-    }
-
     fn enable_user_mode(&mut self, entry: EntryPoint, stack: StackPointer) -> ! {
         let kernel_sp: usize;
         unsafe { core::arch::asm!("mv {0}, sp", out(reg) kernel_sp) };
@@ -97,10 +101,17 @@ impl Platform for RiscVPlatform {
 
     fn map_shared(
         &mut self,
-        _process: ProcessId,
-        _base: PhysicalAddress,
-        _size: PageCount,
-        _permissions: PermissionSet,
+        process: ProcessId,
+        base: PhysicalAddress,
+        size: PageCount,
+        permissions: PermissionSet,
     ) {
+        let pt = self.ensure_page_table(process);
+        let pa = base.raw();
+        let pages = size.value() as usize;
+        let read = permissions.allows(Permission::Read);
+        let write = permissions.allows(Permission::Write);
+        let exec = permissions.allows(Permission::Execute);
+        mmu::map_range(pt, pa, pa, pages, read, write, exec, true, false);
     }
 }