arm64: pgtable: Decouple PGDIR size macros from PGD/PUD/PMD levels

[linux-2.6-microblaze.git] / arch / arm64 / include / asm / kernel-pgtable.h

diff --git a/arch/arm64/include/asm/kernel-pgtable.h b/arch/arm64/include/asm/kernel-pgtable.h
index 742a4b2..f1fc98a 100644 (file)
--- a/arch/arm64/include/asm/kernel-pgtable.h
+++ b/arch/arm64/include/asm/kernel-pgtable.h
@@ -13,27 +13,22 @@
 #include <asm/sparsemem.h>
 
 /*
- * The linear mapping and the start of memory are both 2M aligned (per
- * the arm64 booting.txt requirements). Hence we can use section mapping
- * with 4K (section size = 2M) but not with 16K (section size = 32M) or
- * 64K (section size = 512M).
+ * The physical and virtual addresses of the start of the kernel image are
+ * equal modulo 2 MiB (per the arm64 booting.txt requirements). Hence we can
+ * use section mapping with 4K (section size = 2M) but not with 16K (section
+ * size = 32M) or 64K (section size = 512M).
  */
-
-/*
- * The idmap and swapper page tables need some space reserved in the kernel
- * image. Both require pgd, pud (4 levels only) and pmd tables to (section)
- * map the kernel. With the 64K page configuration, swapper and idmap need to
- * map to pte level. The swapper also maps the FDT (see __create_page_tables
- * for more information). Note that the number of ID map translation levels
- * could be increased on the fly if system RAM is out of reach for the default
- * VA range, so pages required to map highest possible PA are reserved in all
- * cases.
- */
-#ifdef CONFIG_ARM64_4K_PAGES
-#define SWAPPER_PGTABLE_LEVELS (CONFIG_PGTABLE_LEVELS - 1)
+#if defined(PMD_SIZE) && PMD_SIZE <= MIN_KIMG_ALIGN
+#define SWAPPER_BLOCK_SHIFT    PMD_SHIFT
+#define SWAPPER_SKIP_LEVEL     1
 #else
-#define SWAPPER_PGTABLE_LEVELS (CONFIG_PGTABLE_LEVELS)
+#define SWAPPER_BLOCK_SHIFT    PAGE_SHIFT
+#define SWAPPER_SKIP_LEVEL     0
 #endif
+#define SWAPPER_BLOCK_SIZE     (UL(1) << SWAPPER_BLOCK_SHIFT)
+#define SWAPPER_TABLE_SHIFT    (SWAPPER_BLOCK_SHIFT + PAGE_SHIFT - 3)
+
+#define SWAPPER_PGTABLE_LEVELS         (CONFIG_PGTABLE_LEVELS - SWAPPER_SKIP_LEVEL)
 
 #define IDMAP_VA_BITS          48
 #define IDMAP_LEVELS           ARM64_HW_PGTABLE_LEVELS(IDMAP_VA_BITS)
@@ -53,24 +48,13 @@
 #define EARLY_ENTRIES(vstart, vend, shift, add) \
        (SPAN_NR_ENTRIES(vstart, vend, shift) + (add))
 
-#define EARLY_PGDS(vstart, vend, add) (EARLY_ENTRIES(vstart, vend, PGDIR_SHIFT, add))
-
-#if SWAPPER_PGTABLE_LEVELS > 3
-#define EARLY_PUDS(vstart, vend, add) (EARLY_ENTRIES(vstart, vend, PUD_SHIFT, add))
-#else
-#define EARLY_PUDS(vstart, vend, add) (0)
-#endif
+#define EARLY_LEVEL(lvl, vstart, vend, add)    \
+       (SWAPPER_PGTABLE_LEVELS > lvl ? EARLY_ENTRIES(vstart, vend, SWAPPER_BLOCK_SHIFT + lvl * (PAGE_SHIFT - 3), add) : 0)
 
-#if SWAPPER_PGTABLE_LEVELS > 2
-#define EARLY_PMDS(vstart, vend, add) (EARLY_ENTRIES(vstart, vend, SWAPPER_TABLE_SHIFT, add))
-#else
-#define EARLY_PMDS(vstart, vend, add) (0)
-#endif
-
-#define EARLY_PAGES(vstart, vend, add) ( 1                     /* PGDIR page */                                \
-                       + EARLY_PGDS((vstart), (vend), add)     /* each PGDIR needs a next level page table */  \
-                       + EARLY_PUDS((vstart), (vend), add)     /* each PUD needs a next level page table */    \
-                       + EARLY_PMDS((vstart), (vend), add))    /* each PMD needs a next level page table */
+#define EARLY_PAGES(vstart, vend, add) (1      /* PGDIR page */                                \
+       + EARLY_LEVEL(3, (vstart), (vend), add) /* each entry needs a next level page table */  \
+       + EARLY_LEVEL(2, (vstart), (vend), add) /* each entry needs a next level page table */  \
+       + EARLY_LEVEL(1, (vstart), (vend), add))/* each entry needs a next level page table */
 #define INIT_DIR_SIZE (PAGE_SIZE * (EARLY_PAGES(KIMAGE_VADDR, _end, EXTRA_PAGE) + EARLY_SEGMENT_EXTRA_PAGES))
 
 /* the initial ID map may need two extra pages if it needs to be extended */
@@ -81,17 +65,6 @@
 #endif
 #define INIT_IDMAP_DIR_PAGES   EARLY_PAGES(KIMAGE_VADDR, _end + MAX_FDT_SIZE + SWAPPER_BLOCK_SIZE, 1)
 
-/* Initial memory map size */
-#ifdef CONFIG_ARM64_4K_PAGES
-#define SWAPPER_BLOCK_SHIFT    PMD_SHIFT
-#define SWAPPER_BLOCK_SIZE     PMD_SIZE
-#define SWAPPER_TABLE_SHIFT    PUD_SHIFT
-#else
-#define SWAPPER_BLOCK_SHIFT    PAGE_SHIFT
-#define SWAPPER_BLOCK_SIZE     PAGE_SIZE
-#define SWAPPER_TABLE_SHIFT    PMD_SHIFT
-#endif
-
 /* The number of segments in the kernel image (text, rodata, inittext, initdata, data+bss) */
 #define KERNEL_SEGMENT_COUNT   5