From e0b2f2a582c3834a4a42af19967dcb1ef3ed2b3a Mon Sep 17 00:00:00 2001
From: Matheus <matheusuky@gmail.com>
Date: Tue, 16 May 2023 19:35:09 -0300
Subject: [PATCH] mmu: arch_mmu_destroytable

---
 kernel-src/arch/x86-64/mmu.c         | 18 ++++++++++++++++++
 kernel-src/include/x86-64/arch/mmu.h |  1 +
 2 files changed, 19 insertions(+)

diff --git a/kernel-src/arch/x86-64/mmu.c b/kernel-src/arch/x86-64/mmu.c
index 8bc0e10f..edb6cb40 100644
--- a/kernel-src/arch/x86-64/mmu.c
+++ b/kernel-src/arch/x86-64/mmu.c
@@ -111,6 +111,24 @@ static bool add_page(pagetableptr_t top, void *vaddr, uint64_t entry, int depth)
 	return true;
 }
 
+static void destroy(uint64_t *table, int depth) {
+	for (int i = 0; i < 512; ++i) {
+		void *addr = (void *)((*table & ADDRMASK));
+		if (addr == NULL)
+			continue;
+
+		if (depth > 0)
+			destroy(MAKE_HHDM(addr), depth - 1);
+
+		pmm_free(addr, 1);
+	}
+}
+
+void arch_mmu_destroytable(pagetableptr_t table) {
+	destroy(MAKE_HHDM(table), 3);
+	pmm_free(table, 1);
+}
+
 bool arch_mmu_map(pagetableptr_t table, void *paddr, void *vaddr, mmuflags_t flags) {
 	uint64_t entry = ((uintptr_t)paddr & ADDRMASK) | flags;
 	return add_page(table, vaddr, entry, 0);
diff --git a/kernel-src/include/x86-64/arch/mmu.h b/kernel-src/include/x86-64/arch/mmu.h
index fa5971c8..7957ae4c 100644
--- a/kernel-src/include/x86-64/arch/mmu.h
+++ b/kernel-src/include/x86-64/arch/mmu.h
@@ -19,6 +19,7 @@
 typedef uint64_t mmuflags_t;
 typedef uint64_t * pagetableptr_t; // physical address
 
+void arch_mmu_destroytable(pagetableptr_t table);
 bool arch_mmu_map(pagetableptr_t table, void *paddr, void *vaddr, mmuflags_t flags);
 void arch_mmu_invalidate(void *vaddr);
 void arch_mmu_unmap(pagetableptr_t table, void *vaddr);