stos: mm: Add locking to VAD lists

Signed-off-by: Chloe M. <chloe@mensia.org>

paw/stos/head/mm/vad.h

@@ -10,6 +10,7 @@
 #define _MM_VAD_H_ 1
 
 #include <stdef.h>
+#include <ke/spinlock.h>
 
 #define VAD_FROM_VMA(VMA) \
     ((MM_VAD *)(VMA))
@@ -31,10 +32,12 @@ typedef struct _MM_VAD {
  *
  * @First: First entry in VAD list
  * @Last:  Last entry in VAD list
+ * @Lock:  Lock protecting this VAD list
  */
 typedef struct {
     MM_VAD *First;
     MM_VAD *Last;
+    SPINLOCK Lock;
 } MM_VAD_LIST;
 
 /*

paw/stos/mm/vad.c

@@ -19,6 +19,7 @@ MmVadListAppend(MM_VAD_LIST *List, MM_VAD *Vad)
 
     Vad->Next = NULL;
     Vad->Prev = NULL;
+    KeSpinLockAcquire(&List->Lock, true);
 
     if (List->Last == NULL || List->First == NULL) {
         List->Last = Vad;
@@ -29,6 +30,8 @@ MmVadListAppend(MM_VAD_LIST *List, MM_VAD *Vad)
         Last->Next = Vad;
         List->Last = Vad;
     }
+
+    KeSpinLockRelease(&List->Lock);
 }
 
 MM_VAD *
@@ -44,11 +47,13 @@ MmVadListPop(MM_VAD_LIST *List)
         return NULL;
     }
 
+    KeSpinLockAcquire(&List->Lock, true);
     Last = List->Last;
     if (Last->Prev != NULL) {
         Last->Prev->Next = NULL;
     }
 
     List->Last = Last->Prev;
+    KeSpinLockRelease(&List->Lock);
     return Last;
 }

paw/stos/mm/vmm.c

@@ -13,6 +13,7 @@
 #include <hal/page.h>
 #include <ex/trace.h>
 #include <ke/knot.h>
+#include <ke/spinlock.h>
 #include <stapi/status.h>
 #include <string.h>
 
@@ -26,10 +27,8 @@
 static MMU_VAS KernelVas;
 static MM_VAD_LIST VadList;
 static UPTR BumpPtr;
+static SPINLOCK VadListLock;
 
-/*
- * TODO: Add some locking around this
- */
 static ST_STATUS
 MmGrabPages(VOID)
 {
@@ -42,6 +41,7 @@ MmGrabPages(VOID)
     MaxOff = PAGES_PER_GRAB * PAGESIZE;
     HalMmuReadVas(&Vas);
 
+    KeSpinLockAcquire(&VadListLock, true);
     for (USIZE Off = 0; Off < MaxOff; Off += PAGESIZE) {
         /* Don't blast past the limit */
         if ((BumpPtr + Off) >= VALLOC_MAX) {
@@ -51,6 +51,7 @@ MmGrabPages(VOID)
         AllocBase = BumpPtr + Off;
         AllocPfn = MmRequestFrame();
         if (AllocPfn == 0) {
+            KeSpinLockRelease(&VadListLock);
             return STATUS_NO_MEMORY;
         }
 
@@ -63,6 +64,7 @@ MmGrabPages(VOID)
         );
 
         if (Status != STATUS_SUCCESS) {
+            KeSpinLockRelease(&VadListLock);
             return Status;
         }
 
@@ -70,12 +72,10 @@ MmGrabPages(VOID)
     }
 
     BumpPtr = AllocBase;
+    KeSpinLockRelease(&VadListLock);
     return STATUS_SUCCESS;
 }
 
-/*
- * TODO: Consider locking
- */
 VOID *
 MmAllocPages(USIZE Count)
 {
@@ -135,5 +135,8 @@ MmInitVmm(VOID)
 
     HalMmuWriteVas(&KernelVas);
     DTRACE("ah!~... [ok @ %p]\n", VAS_BASE(&KernelVas));
+
     BumpPtr = VALLOC_BASE;
+    KeSpinLockInit(&VadListLock, "vmm-vad");
+    KeSpinLockInit(&VadList.Lock, "vmm-vadlist");
 }