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Diffstat (limited to 'arch/arm64/include/asm/kernel-pgtable.h')
-rw-r--r--arch/arm64/include/asm/kernel-pgtable.h103
1 files changed, 42 insertions, 61 deletions
diff --git a/arch/arm64/include/asm/kernel-pgtable.h b/arch/arm64/include/asm/kernel-pgtable.h
index 83ddb14b95..bf05a77873 100644
--- a/arch/arm64/include/asm/kernel-pgtable.h
+++ b/arch/arm64/include/asm/kernel-pgtable.h
@@ -13,28 +13,27 @@
#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 INIT_IDMAP_PGTABLE_LEVELS (IDMAP_LEVELS - SWAPPER_SKIP_LEVEL)
+
+#define IDMAP_VA_BITS 48
+#define IDMAP_LEVELS ARM64_HW_PGTABLE_LEVELS(IDMAP_VA_BITS)
+#define IDMAP_ROOT_LEVEL (4 - IDMAP_LEVELS)
/*
* A relocatable kernel may execute from an address that differs from the one at
@@ -50,57 +49,39 @@
#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, lvls, vstart, vend, add) \
+ (lvls > 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(lvls, vstart, vend, add) (1 /* PGDIR page */ \
+ + EARLY_LEVEL(3, (lvls), (vstart), (vend), add) /* each entry needs a next level page table */ \
+ + EARLY_LEVEL(2, (lvls), (vstart), (vend), add) /* each entry needs a next level page table */ \
+ + EARLY_LEVEL(1, (lvls), (vstart), (vend), add))/* each entry needs a next level page table */
+#define INIT_DIR_SIZE (PAGE_SIZE * (EARLY_PAGES(SWAPPER_PGTABLE_LEVELS, KIMAGE_VADDR, _end, EXTRA_PAGE) \
+ + EARLY_SEGMENT_EXTRA_PAGES))
-#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 INIT_DIR_SIZE (PAGE_SIZE * EARLY_PAGES(KIMAGE_VADDR, _end, EXTRA_PAGE))
+#define INIT_IDMAP_DIR_PAGES (EARLY_PAGES(INIT_IDMAP_PGTABLE_LEVELS, KIMAGE_VADDR, _end, 1))
+#define INIT_IDMAP_DIR_SIZE ((INIT_IDMAP_DIR_PAGES + EARLY_IDMAP_EXTRA_PAGES) * PAGE_SIZE)
-/* the initial ID map may need two extra pages if it needs to be extended */
-#if VA_BITS < 48
-#define INIT_IDMAP_DIR_SIZE ((INIT_IDMAP_DIR_PAGES + 2) * PAGE_SIZE)
-#else
-#define INIT_IDMAP_DIR_SIZE (INIT_IDMAP_DIR_PAGES * PAGE_SIZE)
-#endif
-#define INIT_IDMAP_DIR_PAGES EARLY_PAGES(KIMAGE_VADDR, _end + MAX_FDT_SIZE + SWAPPER_BLOCK_SIZE, 1)
+#define INIT_IDMAP_FDT_PAGES (EARLY_PAGES(INIT_IDMAP_PGTABLE_LEVELS, 0UL, UL(MAX_FDT_SIZE), 1) - 1)
+#define INIT_IDMAP_FDT_SIZE ((INIT_IDMAP_FDT_PAGES + EARLY_IDMAP_EXTRA_FDT_PAGES) * PAGE_SIZE)
-/* 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
+#if SWAPPER_BLOCK_SIZE > SEGMENT_ALIGN
+#define EARLY_SEGMENT_EXTRA_PAGES (KERNEL_SEGMENT_COUNT + 1)
/*
- * Initial memory map attributes.
+ * The initial ID map consists of the kernel image, mapped as two separate
+ * segments, and may appear misaligned wrt the swapper block size. This means
+ * we need 3 additional pages. The DT could straddle a swapper block boundary,
+ * so it may need 2.
*/
-#define SWAPPER_PTE_FLAGS (PTE_TYPE_PAGE | PTE_AF | PTE_SHARED | PTE_UXN)
-#define SWAPPER_PMD_FLAGS (PMD_TYPE_SECT | PMD_SECT_AF | PMD_SECT_S | PTE_UXN)
-
-#ifdef CONFIG_ARM64_4K_PAGES
-#define SWAPPER_RW_MMUFLAGS (PMD_ATTRINDX(MT_NORMAL) | SWAPPER_PMD_FLAGS | PTE_WRITE)
-#define SWAPPER_RX_MMUFLAGS (SWAPPER_RW_MMUFLAGS | PMD_SECT_RDONLY)
+#define EARLY_IDMAP_EXTRA_PAGES 3
+#define EARLY_IDMAP_EXTRA_FDT_PAGES 2
#else
-#define SWAPPER_RW_MMUFLAGS (PTE_ATTRINDX(MT_NORMAL) | SWAPPER_PTE_FLAGS | PTE_WRITE)
-#define SWAPPER_RX_MMUFLAGS (SWAPPER_RW_MMUFLAGS | PTE_RDONLY)
+#define EARLY_SEGMENT_EXTRA_PAGES 0
+#define EARLY_IDMAP_EXTRA_PAGES 0
+#define EARLY_IDMAP_EXTRA_FDT_PAGES 0
#endif
#endif /* __ASM_KERNEL_PGTABLE_H */