1 files changed, 51 insertions, 0 deletions
diff --git a/arch/riscv/common/vmem.c b/arch/riscv/common/vmem.c
new file mode 100644
index 0000000..17db777
--- /dev/null
+++ b/arch/riscv/common/vmem.c
@@ -0,0 +1,51 @@
+#include <apos/string.h>
+#include <apos/pmem.h>
+#include <pages.h>
+#include <vmem.h>
+
+extern const size_t mm_shifts[10];
+extern const size_t mm_widths[10];
+extern const size_t mm_sizes[10];
+
+#define pte_ppn(pte) (((paddr_t)(pte)) >> 10)
+#define pte_flags(pte) (((paddr_t)(pte)) & 0xff)
+#define to_pte(p, f) ((paddr_to_pnum(p) << 10) + (f))
+#define pte_addr(pte) (pnum_to_paddr(pte_ppn(pte)))
+
+/* probably not actually this simple, right? */
+void map_vmem(struct vm_branch_t *branch,
+		paddr_t paddr, vaddr_t vaddr,
+		uint8_t flags, enum mm_order_t order)
+{
+	enum mm_order_t top = MAX_ORDER;
+	while(top != order){
+		size_t idx = paddr_to_index(vaddr, top);
+
+		if(!branch->leaf[idx]){
+			paddr_t new_leaf = alloc_page(MM_KPAGE, 0);
+			branch->leaf[idx] = (struct vm_branch_t *)to_pte(new_leaf, VM_V);
+			memset((void *)new_leaf, 0, sizeof(struct vm_branch_t));
+		}
+
+		branch = (struct vm_branch_t *)pte_addr(branch->leaf[idx]);
+		top--;
+	}
+
+	size_t idx = paddr_to_index(vaddr, top);
+	branch->leaf[idx] = (struct vm_branch_t *)to_pte(paddr, flags);
+}
+
+void unmap_vmem(struct vm_branch_t *branch,
+		vaddr_t vaddr, enum mm_order_t order)
+{
+	while(order){
+		size_t idx = paddr_to_index(vaddr, order);
+		branch = (struct vm_branch_t *)pte_addr(branch->leaf[idx]);
+	}
+
+	size_t idx = paddr_to_index(vaddr, order);
+	if(branch->leaf[idx])
+		free_page(order, pte_addr(branch->leaf[idx]));
+
+	branch->leaf[idx] = 0;
+}