Changeset c03ee1c in mainline for kernel/arch/ia32/include/mm

Timestamp:

2007-06-13T17:49:57Z (18 years ago)

Author:

Jakub Jermar <jakub@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

de7663f

Parents:

6b781c0

Message:

Improve comments for arch-specific implementations of hierarchical
4-level page tables. Improve formatting.

File:

• kernel/arch/ia32/include/mm/page.h (modified) (6 diffs)

kernel/arch/ia32/include/mm/page.h

@@ -57 +57 @@
  * IA-32 has 2-level page tables, so PTL1 and PTL2 are left out.
  */
+
+/* Number of entries in each level. */
 #define PTL0_ENTRIES_ARCH       1024
 #define PTL1_ENTRIES_ARCH       0
@@ -62 +64 @@
 #define PTL3_ENTRIES_ARCH       1024
 
-#define PTL0_SIZE_ARCH       ONE_FRAME
-#define PTL1_SIZE_ARCH       0
-#define PTL2_SIZE_ARCH       0
-#define PTL3_SIZE_ARCH       ONE_FRAME
+/* Page table sizes for each level. */
+#define PTL0_SIZE_ARCH          ONE_FRAME
+#define PTL1_SIZE_ARCH          0
+#define PTL2_SIZE_ARCH          0
+#define PTL3_SIZE_ARCH          ONE_FRAME
 
+/* Macros calculating indices for each level. */
 #define PTL0_INDEX_ARCH(vaddr)  (((vaddr) >> 22) & 0x3ff)
 #define PTL1_INDEX_ARCH(vaddr)  0
@@ -72 +76 @@
 #define PTL3_INDEX_ARCH(vaddr)  (((vaddr) >> 12) & 0x3ff)
 
-#define GET_PTL1_ADDRESS_ARCH(ptl0, i)          ((pte_t *)((((pte_t *)(ptl0))[(i)].frame_address) << 12))
-#define GET_PTL2_ADDRESS_ARCH(ptl1, i)          (ptl1)
-#define GET_PTL3_ADDRESS_ARCH(ptl2, i)          (ptl2)
-#define GET_FRAME_ADDRESS_ARCH(ptl3, i)         ((uintptr_t)((((pte_t *)(ptl3))[(i)].frame_address) << 12))
+/* Get PTE address accessors for each level. */
+#define GET_PTL1_ADDRESS_ARCH(ptl0, i) \
+        ((pte_t *) ((((pte_t *) (ptl0))[(i)].frame_address) << 12))
+#define GET_PTL2_ADDRESS_ARCH(ptl1, i) \
+        (ptl1)
+#define GET_PTL3_ADDRESS_ARCH(ptl2, i) \
+        (ptl2)
+#define GET_FRAME_ADDRESS_ARCH(ptl3, i) \
+        ((uintptr_t) ((((pte_t *) (ptl3))[(i)].frame_address) << 12))
 
-#define SET_PTL0_ADDRESS_ARCH(ptl0)             (write_cr3((uintptr_t) (ptl0)))
-#define SET_PTL1_ADDRESS_ARCH(ptl0, i, a)       (((pte_t *)(ptl0))[(i)].frame_address = (a)>>12)
+/* Set PTE address accessors for each level. */
+#define SET_PTL0_ADDRESS_ARCH(ptl0) \
+        (write_cr3((uintptr_t) (ptl0)))
+#define SET_PTL1_ADDRESS_ARCH(ptl0, i, a) \
+        (((pte_t *) (ptl0))[(i)].frame_address = (a) >> 12)
 #define SET_PTL2_ADDRESS_ARCH(ptl1, i, a)
 #define SET_PTL3_ADDRESS_ARCH(ptl2, i, a)
-#define SET_FRAME_ADDRESS_ARCH(ptl3, i, a)      (((pte_t *)(ptl3))[(i)].frame_address = (a)>>12)
+#define SET_FRAME_ADDRESS_ARCH(ptl3, i, a) \
+        (((pte_t *) (ptl3))[(i)].frame_address = (a) >> 12)
 
-#define GET_PTL1_FLAGS_ARCH(ptl0, i)            get_pt_flags((pte_t *)(ptl0), (index_t)(i))
-#define GET_PTL2_FLAGS_ARCH(ptl1, i)            PAGE_PRESENT
-#define GET_PTL3_FLAGS_ARCH(ptl2, i)            PAGE_PRESENT
-#define GET_FRAME_FLAGS_ARCH(ptl3, i)           get_pt_flags((pte_t *)(ptl3), (index_t)(i))
+/* Get PTE flags accessors for each level. */
+#define GET_PTL1_FLAGS_ARCH(ptl0, i) \
+        get_pt_flags((pte_t *) (ptl0), (index_t) (i))
+#define GET_PTL2_FLAGS_ARCH(ptl1, i) \
+        PAGE_PRESENT
+#define GET_PTL3_FLAGS_ARCH(ptl2, i) \
+        PAGE_PRESENT
+#define GET_FRAME_FLAGS_ARCH(ptl3, i) \
+        get_pt_flags((pte_t *) (ptl3), (index_t) (i))
 
-#define SET_PTL1_FLAGS_ARCH(ptl0, i, x)         set_pt_flags((pte_t *)(ptl0), (index_t)(i), (x))
+/* Set PTE flags accessors for each level. */
+#define SET_PTL1_FLAGS_ARCH(ptl0, i, x) \
+        set_pt_flags((pte_t *) (ptl0), (index_t) (i), (x))
 #define SET_PTL2_FLAGS_ARCH(ptl1, i, x)
 #define SET_PTL3_FLAGS_ARCH(ptl2, i, x)
-#define SET_FRAME_FLAGS_ARCH(ptl3, i, x)        set_pt_flags((pte_t *)(ptl3), (index_t)(i), (x))
+#define SET_FRAME_FLAGS_ARCH(ptl3, i, x) \
+        set_pt_flags((pte_t *) (ptl3), (index_t) (i), (x))
 
-#define PTE_VALID_ARCH(p)                       (*((uint32_t *) (p)) != 0)
-#define PTE_PRESENT_ARCH(p)                     ((p)->present != 0)
-#define PTE_GET_FRAME_ARCH(p)                   ((p)->frame_address << FRAME_WIDTH)
-#define PTE_WRITABLE_ARCH(p)                    ((p)->writeable != 0)
+/* Macros for querying the last level entries. */
+#define PTE_VALID_ARCH(p) \
+        (*((uint32_t *) (p)) != 0)
+#define PTE_PRESENT_ARCH(p) \
+        ((p)->present != 0)
+#define PTE_GET_FRAME_ARCH(p) \
+        ((p)->frame_address << FRAME_WIDTH)
+#define PTE_WRITABLE_ARCH(p) \
+        ((p)->writeable != 0)
 #define PTE_EXECUTABLE_ARCH(p)                  1
 
@@ -106 +132 @@
 /* Page fault error codes. */
 
-/** When bit on this position is 0, the page fault was caused by a not-present page. */
+/** When bit on this position is 0, the page fault was caused by a not-present
+ * page.
+ */
 #define PFERR_CODE_P            (1 << 0)
 
@@ -122 +150 @@
         pte_t *p = &pt[i];
         
-        return (
-                (!p->page_cache_disable) << PAGE_CACHEABLE_SHIFT |
-                (!p->present) << PAGE_PRESENT_SHIFT |
-                p->uaccessible << PAGE_USER_SHIFT |
-                1<<PAGE_READ_SHIFT |
-                p->writeable << PAGE_WRITE_SHIFT |
-                1<<PAGE_EXEC_SHIFT |
-                p->global << PAGE_GLOBAL_SHIFT
-        );
+        return ((!p->page_cache_disable) << PAGE_CACHEABLE_SHIFT |
+            (!p->present) << PAGE_PRESENT_SHIFT |
+            p->uaccessible << PAGE_USER_SHIFT |
+            1 << PAGE_READ_SHIFT |
+            p->writeable << PAGE_WRITE_SHIFT |
+            1 << PAGE_EXEC_SHIFT |
+            p->global << PAGE_GLOBAL_SHIFT);
 }
 
@@ -144 +170 @@
         
         /*
-         * Ensure that there is at least one bit set even if the present bit is cleared.
+         * Ensure that there is at least one bit set even if the present bit is
+         * cleared.
          */
         p->soft_valid = true;