X-Git-Url: https://scm.lunaixsky.com/lunaix-os.git/blobdiff_plain/7b0dccbab69e806a63c4504c3ddb82e45241985b..b60166b327a9108b07e3069fa6568a451529ffd9:/lunaix-os/kernel/mm/vmm.c?ds=sidebyside

diff --git a/lunaix-os/kernel/mm/vmm.c b/lunaix-os/kernel/mm/vmm.c
index 54da656..5e09e9d 100644
--- a/lunaix-os/kernel/mm/vmm.c
+++ b/lunaix-os/kernel/mm/vmm.c
@@ -1,22 +1,25 @@
-#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>
+#include <lunaix/syslog.h>
 
-#include <stdbool.h>
+#include <sys/cpu.h>
+#include <sys/mm/mm_defs.h>
+
+LOG_MODULE("VMM")
 
 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(PP_FGPERSIST);
     for (size_t i = 0; i < PG_MAX_ENTRIES; i++) {
         dir->entry[i] = PTE_NULL;
     }
@@ -28,189 +31,201 @@ 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(ptr_t mnt, ptr_t va, ptr_t pa, pt_attr attr, int options)
 {
-    x86_page_table* l1pt = (x86_page_table*)L1_BASE_VADDR;
-    x86_page_table* l2pt = (x86_page_table*)L2_VADDR(l1_inx);
+    assert((ptr_t)va % PG_SIZE == 0);
+
+    ptr_t l1_inx = L1_INDEX(va);
+    ptr_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_pte_t* l1pte = &l1pt->entry[l1_inx];
+    if (!*l1pte) {
+        x86_page_table* new_l1pt_pa =
+          (x86_page_table*)pmm_alloc_page(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);
-    }
-
-    if (!forced && l2pt->entry[l2_inx]) {
-        return 0;
-    }
+        // This must be writable
+        *l1pte = NEW_L1_ENTRY(attr | PG_WRITE | PG_PRESENT, new_l1pt_pa);
 
-    l2pt->entry[l2_inx] = NEW_L2_ENTRY(attr, pa);
+        // make sure our new l2 table is visible to CPU
+        cpu_flush_page((ptr_t)l2pt);
 
-    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);
+        memset((void*)l2pt, 0, PG_SIZE);
+    } else {
+        if ((attr & PG_ALLOW_USER) && !(*l1pte & PG_ALLOW_USER)) {
+            *l1pte |= PG_ALLOW_USER;
         }
-        // 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));
+
+        x86_pte_t pte = l2pt->entry[l2_inx];
+        if (pte && (options & VMAP_IGNORE)) {
+            return 1;
         }
-        l2_index++;
     }
 
-    // 页目录与所有页表已满！
-    if (l1_index > PG_MAX_ENTRIES) {
-        return NULL;
+    if (mnt == VMS_SELF) {
+        cpu_flush_page(va);
     }
 
-    if (!__vmm_map_internal(l1_index, l2_index, (uintptr_t)pa, tattr, false)) {
-        return NULL;
+    if ((options & VMAP_NOMAP)) {
+        return 1;
     }
 
-    return (void*)V_ADDR(l1_index, l2_index, PG_OFFSET(va));
+    if (!(options & VMAP_GUARDPAGE)) {
+        l2pt->entry[l2_inx] = NEW_L2_ENTRY(attr, pa);
+    } else {
+        l2pt->entry[l2_inx] = MEMGUARD;
+    }
+    
+    return 1;
 }
 
-void*
-vmm_fmap_page(void* va, void* pa, pt_attr tattr)
+ptr_t
+vmm_del_mapping(ptr_t mnt, ptr_t va)
 {
-    if (!pa || !va) {
-        return NULL;
+    assert(((ptr_t)va & 0xFFFU) == 0);
+
+    u32_t l1_index = L1_INDEX(va);
+    u32_t l2_index = L2_INDEX(va);
+
+    // prevent unmap of recursive mapping region
+    if (l1_index == 1023) {
+        return 0;
     }
 
-    assert(((uintptr_t)va & 0xFFFU) == 0) assert(((uintptr_t)pa & 0xFFFU) == 0);
+    x86_page_table* l1pt = (x86_page_table*)(mnt | (1023 << 12));
 
-    uint32_t l1_index = L1_INDEX(va);
-    uint32_t l2_index = L2_INDEX(va);
+    x86_pte_t l1pte = l1pt->entry[l1_index];
 
-    if (!__vmm_map_internal(l1_index, l2_index, (uintptr_t)pa, tattr, true)) {
-        return NULL;
-    }
+    if (l1pte) {
+        x86_page_table* l2pt = (x86_page_table*)(mnt | (l1_index << 12));
+        x86_pte_t l2pte = l2pt->entry[l2_index];
+
+        cpu_flush_page(va);
+        l2pt->entry[l2_index] = PTE_NULL;
 
-    cpu_invplg(va);
+        return PG_ENTRY_ADDR(l2pte);
+    }
 
-    return (void*)V_ADDR(l1_index, l2_index, PG_OFFSET(va));
+    return 0;
 }
 
-void*
-vmm_alloc_page(void* vpn, pt_attr tattr)
+int
+vmm_lookup(ptr_t va, v_mapping* mapping)
 {
-    void* pp = pmm_alloc_page();
-    void* result = vmm_map_page(vpn, pp, tattr);
-    if (!result) {
-        pmm_free_page(pp);
-    }
-    return result;
+    return vmm_lookupat(VMS_SELF, va, mapping);
 }
 
 int
-vmm_alloc_pages(void* va, size_t sz, pt_attr tattr)
+vmm_lookupat(ptr_t mnt, ptr_t va, v_mapping* mapping)
 {
-    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;
+    u32_t l1_index = L1_INDEX(va);
+    u32_t l2_index = L2_INDEX(va);
+
+    x86_page_table* l1pt = (x86_page_table*)(mnt | 1023 << 12);
+    x86_pte_t l1pte = l1pt->entry[l1_index];
+
+    if (l1pte) {
+        x86_pte_t* l2pte =
+          &((x86_page_table*)(mnt | (l1_index << 12)))->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->pte = l2pte;
+            mapping->va = va;
+            return 1;
         }
     }
 
-    return true;
+    return 0;
 }
 
-void
-vmm_unmap_page(void* va)
+ptr_t
+vmm_v2p(ptr_t va)
 {
-    assert(((uintptr_t)va & 0xFFFU) == 0);
+    u32_t l1_index = L1_INDEX(va);
+    u32_t l2_index = L2_INDEX(va);
 
-    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_pte_t l1pte = l1pt->entry[l1_index];
 
     if (l1pte) {
-        x86_page_table* l2pt = (x86_page_table*)L2_VADDR(l1_index);
-        x86_pte_t l2pte = l2pt->entry[l2_index];
-        if (IS_CACHED(l2pte)) {
-            pmm_free_page((void*)l2pte);
+        x86_pte_t* l2pte =
+          &((x86_page_table*)L2_VADDR(l1_index))->entry[l2_index];
+
+        if (l2pte) {
+            return PG_ENTRY_ADDR(*l2pte) | ((ptr_t)va & 0xfff);
         }
-        cpu_invplg(va);
-        l2pt->entry[l2_index] = PTE_NULL;
     }
+    return 0;
 }
 
-v_mapping
-vmm_lookup(void* va)
+ptr_t
+vmm_v2pat(ptr_t mnt, ptr_t va)
 {
-    assert(((uintptr_t)va & 0xFFFU) == 0);
+    u32_t l1_index = L1_INDEX(va);
+    u32_t l2_index = L2_INDEX(va);
 
-    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];
 
-    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*)(mnt | (l1_index << 12)))->entry[l2_index];
+
         if (l2pte) {
-            mapping.flags = PG_ENTRY_FLAGS(l2pte);
-            mapping.pa = PG_ENTRY_ADDR(l2pte);
-            mapping.pn = mapping.pa >> PG_SIZE_BITS;
+            return PG_ENTRY_ADDR(*l2pte) | ((ptr_t)va & 0xfff);
         }
     }
+    return 0;
+}
+
+ptr_t
+vmm_mount_pd(ptr_t mnt, ptr_t pde)
+{
+    assert(pde);
+
+    x86_page_table* l1pt = (x86_page_table*)L1_BASE_VADDR;
+    l1pt->entry[(mnt >> 22)] = NEW_L1_ENTRY(T_SELF_REF_PERM, pde);
+    cpu_flush_page(mnt);
+    return mnt;
+}
 
-    return mapping;
+ptr_t
+vmm_unmount_pd(ptr_t mnt)
+{
+    x86_page_table* l1pt = (x86_page_table*)L1_BASE_VADDR;
+    l1pt->entry[(mnt >> 22)] = 0;
+    cpu_flush_page(mnt);
+    return mnt;
 }
 
-void*
-vmm_v2p(void* va)
+ptr_t
+vmm_dup_page(ptr_t pa)
 {
-    return (void*)vmm_lookup(va).pa;
+    ptr_t new_ppg = pmm_alloc_page(0);
+    vmm_set_mapping(VMS_SELF, PG_MOUNT_3, new_ppg, PG_PREM_RW, VMAP_NULL);
+    vmm_set_mapping(VMS_SELF, PG_MOUNT_4, pa, PG_PREM_RW, VMAP_NULL);
+
+    asm volatile("movl %1, %%edi\n"
+                 "movl %2, %%esi\n"
+                 "rep movsl\n" ::"c"(1024),
+                 "r"(PG_MOUNT_3),
+                 "r"(PG_MOUNT_4)
+                 : "memory", "%edi", "%esi");
+
+    vmm_del_mapping(VMS_SELF, PG_MOUNT_3);
+    vmm_del_mapping(VMS_SELF, PG_MOUNT_4);
+
+    return new_ppg;
 }
\ No newline at end of file