X-Git-Url: https://scm.lunaixsky.com/lunaix-os.git/blobdiff_plain/b0c2a4be2d1f4f93ab01d0858979a12ef0735ec1..61bcf0c65dac58d2f29ab40e016489c89ec8eec0:/lunaix-os/kernel/mm/vmm.c

diff --git a/lunaix-os/kernel/mm/vmm.c b/lunaix-os/kernel/mm/vmm.c
index e1f769d..55fe52b 100644
--- a/lunaix-os/kernel/mm/vmm.c
+++ b/lunaix-os/kernel/mm/vmm.c
@@ -1,6 +1,5 @@
 #include <hal/cpu.h>
-#include <libc/string.h>
-#include <lunaix/mm/page.h>
+#include <klibc/string.h>
 #include <lunaix/mm/pmm.h>
 #include <lunaix/mm/vmm.h>
 #include <lunaix/spike.h>
@@ -10,13 +9,14 @@
 void
 vmm_init()
 {
-    // TODO: something here?
+    // XXX: something here?
 }
 
 x86_page_table*
 vmm_init_pd()
 {
-    x86_page_table* dir = (x86_page_table*)pmm_alloc_page();
+    x86_page_table* dir =
+      (x86_page_table*)pmm_alloc_page(KERNEL_PID, PP_FGPERSIST);
     for (size_t i = 0; i < PG_MAX_ENTRIES; i++) {
         dir->entry[i] = PTE_NULL;
     }
@@ -28,172 +28,69 @@ vmm_init_pd()
 }
 
 int
-__vmm_map_internal(uint32_t l1_inx,
-                   uint32_t l2_inx,
-                   uintptr_t pa,
-                   pt_attr attr,
-                   int forced)
+vmm_set_mapping(uintptr_t mnt, uintptr_t va, uintptr_t pa, pt_attr attr)
 {
-    x86_page_table* l1pt = (x86_page_table*)L1_BASE_VADDR;
-    x86_page_table* l2pt = (x86_page_table*)L2_VADDR(l1_inx);
+    assert((uintptr_t)va % PG_SIZE == 0);
+
+    uintptr_t l1_inx = L1_INDEX(va);
+    uintptr_t l2_inx = L2_INDEX(va);
+    x86_page_table* l1pt = (x86_page_table*)(mnt | (1023 << 12));
+    x86_page_table* l2pt = (x86_page_table*)(mnt | (l1_inx << 12));
 
     // See if attr make sense
     assert(attr <= 128);
 
     if (!l1pt->entry[l1_inx]) {
-        x86_page_table* new_l1pt_pa = pmm_alloc_page();
+        x86_page_table* new_l1pt_pa = pmm_alloc_page(KERNEL_PID, PP_FGPERSIST);
 
         // 物理内存已满！
         if (!new_l1pt_pa) {
             return 0;
         }
 
-        l1pt->entry[l1_inx] = NEW_L1_ENTRY(attr, new_l1pt_pa);
-        memset((void*)L2_VADDR(l1_inx), 0, PG_SIZE);
+        // This must be writable
+        l1pt->entry[l1_inx] = NEW_L1_ENTRY(attr | PG_WRITE, new_l1pt_pa);
+        memset((void*)l2pt, 0, PG_SIZE);
     }
 
-    x86_pte_t l2pte = l2pt->entry[l2_inx];
-    if (l2pte) {
-        if (!forced) {
-            return 0;
-        }
-        if (HAS_FLAGS(l2pte, PG_PRESENT)) {
-            assert_msg(pmm_free_page(GET_PG_ADDR(l2pte)), "fail to release physical page");
-        }
+    if (mnt == PD_REFERENCED) {
+        cpu_invplg(va);
     }
 
     l2pt->entry[l2_inx] = NEW_L2_ENTRY(attr, pa);
-
     return 1;
 }
 
-void*
-vmm_map_page(void* va, void* pa, pt_attr tattr)
-{
-    // 显然，对空指针进行映射没有意义。
-    if (!pa || !va) {
-        return NULL;
-    }
-
-    assert(((uintptr_t)va & 0xFFFU) == 0) assert(((uintptr_t)pa & 0xFFFU) == 0);
-
-    uint32_t l1_index = L1_INDEX(va);
-    uint32_t l2_index = L2_INDEX(va);
-    x86_page_table* l1pt = (x86_page_table*)L1_BASE_VADDR;
-
-    // 在页表与页目录中找到一个可用的空位进行映射（位于va或其附近）
-    x86_pte_t l1pte = l1pt->entry[l1_index];
-    x86_page_table* l2pt = (x86_page_table*)L2_VADDR(l1_index);
-    while (l1pte && l1_index < PG_MAX_ENTRIES) {
-        if (l2_index == PG_MAX_ENTRIES) {
-            l1_index++;
-            l2_index = 0;
-            l1pte = l1pt->entry[l1_index];
-            l2pt = (x86_page_table*)L2_VADDR(l1_index);
-        }
-        // 页表有空位，只需要开辟一个新的 PTE (Level 2)
-        if (l2pt && !l2pt->entry[l2_index]) {
-            l2pt->entry[l2_index] = NEW_L2_ENTRY(tattr, pa);
-            return (void*)V_ADDR(l1_index, l2_index, PG_OFFSET(va));
-        }
-        l2_index++;
-    }
-
-    // 页目录与所有页表已满！
-    if (l1_index > PG_MAX_ENTRIES) {
-        return NULL;
-    }
-
-    if (!__vmm_map_internal(l1_index, l2_index, (uintptr_t)pa, tattr, false)) {
-        return NULL;
-    }
-
-    return (void*)V_ADDR(l1_index, l2_index, PG_OFFSET(va));
-}
-
-void*
-vmm_fmap_page(void* va, void* pa, pt_attr tattr)
+int
+vmm_del_mapping(uintptr_t mnt, uintptr_t va)
 {
-    if (!pa || !va) {
-        return NULL;
-    }
-
-    assert(((uintptr_t)va & 0xFFFU) == 0) assert(((uintptr_t)pa & 0xFFFU) == 0);
+    assert(((uintptr_t)va & 0xFFFU) == 0);
 
     uint32_t l1_index = L1_INDEX(va);
     uint32_t l2_index = L2_INDEX(va);
 
-    if (!__vmm_map_internal(l1_index, l2_index, (uintptr_t)pa, tattr, true)) {
-        return NULL;
+    // prevent unmap of recursive mapping region
+    if (l1_index == 1023) {
+        return 0;
     }
 
-    cpu_invplg(va);
-
-    return (void*)V_ADDR(l1_index, l2_index, PG_OFFSET(va));
-}
-
-void*
-vmm_alloc_page(void* vpn, pt_attr tattr)
-{
-    void* pp = pmm_alloc_page();
-    void* result = vmm_map_page(vpn, pp, tattr);
-    if (!result) {
-        pmm_free_page(pp);
-    }
-    return result;
-}
-
-int
-vmm_alloc_pages(void* va, size_t sz, pt_attr tattr)
-{
-    assert((uintptr_t)va % PG_SIZE == 0) assert(sz % PG_SIZE == 0);
-
-    void* va_ = va;
-    for (size_t i = 0; i < (sz >> PG_SIZE_BITS); i++, va_ += PG_SIZE) {
-        void* pp = pmm_alloc_page();
-        uint32_t l1_index = L1_INDEX(va_);
-        uint32_t l2_index = L2_INDEX(va_);
-        if (!pp || !__vmm_map_internal(
-                     l1_index, l2_index, (uintptr_t)pp, tattr, false)) {
-            // if one failed, release previous allocated pages.
-            va_ = va;
-            for (size_t j = 0; j < i; j++, va_ += PG_SIZE) {
-                vmm_unmap_page(va_);
-            }
-
-            return false;
-        }
-    }
-
-    return true;
-}
-
-void
-vmm_unmap_page(void* va)
-{
-    assert(((uintptr_t)va & 0xFFFU) == 0);
-
-    uint32_t l1_index = L1_INDEX(va);
-    uint32_t l2_index = L2_INDEX(va);
-    x86_page_table* l1pt = (x86_page_table*)L1_BASE_VADDR;
+    x86_page_table* l1pt = (x86_page_table*)(mnt | (1023 << 12));
 
     x86_pte_t l1pte = l1pt->entry[l1_index];
 
     if (l1pte) {
-        x86_page_table* l2pt = (x86_page_table*)L2_VADDR(l1_index);
+        x86_page_table* l2pt = (x86_page_table*)(mnt | (l1_index << 12));
         x86_pte_t l2pte = l2pt->entry[l2_index];
-        if (IS_CACHED(l2pte)) {
-            pmm_free_page((void*)l2pte);
-        }
+
         cpu_invplg(va);
         l2pt->entry[l2_index] = PTE_NULL;
     }
 }
 
-v_mapping
-vmm_lookup(void* va)
+int
+vmm_lookup(uintptr_t va, v_mapping* mapping)
 {
-    assert(((uintptr_t)va & 0xFFFU) == 0);
+    // va = va & ~0xfff;
 
     uint32_t l1_index = L1_INDEX(va);
     uint32_t l2_index = L2_INDEX(va);
@@ -201,22 +98,34 @@ vmm_lookup(void* va)
     x86_page_table* l1pt = (x86_page_table*)L1_BASE_VADDR;
     x86_pte_t l1pte = l1pt->entry[l1_index];
 
-    v_mapping mapping = { .flags = 0, .pa = 0, .pn = 0 };
     if (l1pte) {
-        x86_pte_t l2pte =
-          ((x86_page_table*)L2_VADDR(l1_index))->entry[l2_index];
+        x86_pte_t* l2pte =
+          &((x86_page_table*)L2_VADDR(l1_index))->entry[l2_index];
         if (l2pte) {
-            mapping.flags = PG_ENTRY_FLAGS(l2pte);
-            mapping.pa = PG_ENTRY_ADDR(l2pte);
-            mapping.pn = mapping.pa >> PG_SIZE_BITS;
+            mapping->flags = PG_ENTRY_FLAGS(*l2pte);
+            mapping->pa = PG_ENTRY_ADDR(*l2pte);
+            mapping->pn = mapping->pa >> PG_SIZE_BITS;
+            mapping->pte = l2pte;
+            mapping->va = va;
+            return 1;
         }
     }
+    return 0;
+}
 
-    return mapping;
+void*
+vmm_mount_pd(uintptr_t mnt, void* pde)
+{
+    x86_page_table* l1pt = (x86_page_table*)L1_BASE_VADDR;
+    l1pt->entry[(mnt >> 22)] = NEW_L1_ENTRY(T_SELF_REF_PERM, pde);
+    cpu_invplg(mnt);
+    return mnt;
 }
 
 void*
-vmm_v2p(void* va)
+vmm_unmount_pd(uintptr_t mnt)
 {
-    return (void*)vmm_lookup(va).pa;
+    x86_page_table* l1pt = (x86_page_table*)L1_BASE_VADDR;
+    l1pt->entry[(mnt >> 22)] = 0;
+    cpu_invplg(mnt);
 }
\ No newline at end of file