omap iommu: cleanup iommu page address mask and definitions

This is just a cleanup, but adds a few macros here, which can be used
in the proceeding patches.

Signed-off-by: Hiroshi DOYU <Hiroshi.DOYU@nokia.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

diff --git a/arch/arm/plat-omap/iopgtable.h b/arch/arm/plat-omap/iopgtable.h
index 37dac43..ab23b6a 100644 (file)
--- a/arch/arm/plat-omap/iopgtable.h
+++ b/arch/arm/plat-omap/iopgtable.h
@@ -1,7 +1,7 @@
 /*
  * omap iommu: pagetable definitions
  *
- * Copyright (C) 2008-2009 Nokia Corporation
+ * Copyright (C) 2008-2010 Nokia Corporation
  *
  * Written by Hiroshi DOYU <Hiroshi.DOYU@nokia.com>
  *
@@ -13,26 +13,52 @@
 #ifndef __PLAT_OMAP_IOMMU_H
 #define __PLAT_OMAP_IOMMU_H
 
+/*
+ * "L2 table" address mask and size definitions.
+ */
 #define IOPGD_SHIFT            20
-#define IOPGD_SIZE             (1 << IOPGD_SHIFT)
+#define IOPGD_SIZE             (1UL << IOPGD_SHIFT)
 #define IOPGD_MASK             (~(IOPGD_SIZE - 1))
-#define IOSECTION_MASK         IOPGD_MASK
-#define PTRS_PER_IOPGD         (1 << (32 - IOPGD_SHIFT))
-#define IOPGD_TABLE_SIZE       (PTRS_PER_IOPGD * sizeof(u32))
 
-#define IOSUPER_SIZE           (IOPGD_SIZE << 4)
+/*
+ * "section" address mask and size definitions.
+ */
+#define IOSECTION_SHIFT                20
+#define IOSECTION_SIZE         (1UL << IOSECTION_SHIFT)
+#define IOSECTION_MASK         (~(IOSECTION_SIZE - 1))
+
+/*
+ * "supersection" address mask and size definitions.
+ */
+#define IOSUPER_SHIFT          24
+#define IOSUPER_SIZE           (1UL << IOSUPER_SHIFT)
 #define IOSUPER_MASK           (~(IOSUPER_SIZE - 1))
 
+#define PTRS_PER_IOPGD         (1UL << (32 - IOPGD_SHIFT))
+#define IOPGD_TABLE_SIZE       (PTRS_PER_IOPGD * sizeof(u32))
+
+/*
+ * "small page" address mask and size definitions.
+ */
 #define IOPTE_SHIFT            12
-#define IOPTE_SIZE             (1 << IOPTE_SHIFT)
+#define IOPTE_SIZE             (1UL << IOPTE_SHIFT)
 #define IOPTE_MASK             (~(IOPTE_SIZE - 1))
-#define IOPAGE_MASK            IOPTE_MASK
-#define PTRS_PER_IOPTE         (1 << (IOPGD_SHIFT - IOPTE_SHIFT))
-#define IOPTE_TABLE_SIZE       (PTRS_PER_IOPTE * sizeof(u32))
 
-#define IOLARGE_SIZE           (IOPTE_SIZE << 4)
+/*
+ * "large page" address mask and size definitions.
+ */
+#define IOLARGE_SHIFT          16
+#define IOLARGE_SIZE           (1UL << IOLARGE_SHIFT)
 #define IOLARGE_MASK           (~(IOLARGE_SIZE - 1))
 
+#define PTRS_PER_IOPTE         (1UL << (IOPGD_SHIFT - IOPTE_SHIFT))
+#define IOPTE_TABLE_SIZE       (PTRS_PER_IOPTE * sizeof(u32))
+
+#define IOPAGE_MASK            IOPTE_MASK
+
+/*
+ * some descriptor attributes.
+ */
 #define IOPGD_TABLE            (1 << 0)
 #define IOPGD_SECTION          (2 << 0)
 #define IOPGD_SUPER            (1 << 18 | 2 << 0)
@@ -40,12 +66,14 @@
 #define IOPTE_SMALL            (2 << 0)
 #define IOPTE_LARGE            (1 << 0)
 
+/* to find an entry in a page-table-directory */
 #define iopgd_index(da)                (((da) >> IOPGD_SHIFT) & (PTRS_PER_IOPGD - 1))
 #define iopgd_offset(obj, da)  ((obj)->iopgd + iopgd_index(da))
 
 #define iopte_paddr(iopgd)     (*iopgd & ~((1 << 10) - 1))
 #define iopte_vaddr(iopgd)     ((u32 *)phys_to_virt(iopte_paddr(iopgd)))
 
+/* to find an entry in the second-level page table. */
 #define iopte_index(da)                (((da) >> IOPTE_SHIFT) & (PTRS_PER_IOPTE - 1))
 #define iopte_offset(iopgd, da)        (iopte_vaddr(iopgd) + iopte_index(da))