1 files changed, 111 insertions, 0 deletions
diff --git a/arch/x86/include/asm/pgtable_32.h b/arch/x86/include/asm/pgtable_32.h
new file mode 100644
index 000000000..71e1df860
--- /dev/null
+++ b/arch/x86/include/asm/pgtable_32.h
@@ -0,0 +1,111 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_X86_PGTABLE_32_H
+#define _ASM_X86_PGTABLE_32_H
+
+#include <asm/pgtable_32_types.h>
+
+/*
+ * The Linux memory management assumes a three-level page table setup. On
+ * the i386, we use that, but "fold" the mid level into the top-level page
+ * table, so that we physically have the same two-level page table as the
+ * i386 mmu expects.
+ *
+ * This file contains the functions and defines necessary to modify and use
+ * the i386 page table tree.
+ */
+#ifndef __ASSEMBLY__
+#include <asm/processor.h>
+#include <linux/threads.h>
+#include <asm/paravirt.h>
+
+#include <linux/bitops.h>
+#include <linux/list.h>
+#include <linux/spinlock.h>
+
+struct mm_struct;
+struct vm_area_struct;
+
+extern pgd_t swapper_pg_dir[1024];
+extern pgd_t initial_page_table[1024];
+extern pmd_t initial_pg_pmd[];
+
+static inline void pgtable_cache_init(void) { }
+static inline void check_pgt_cache(void) { }
+void paging_init(void);
+void sync_initial_page_table(void);
+
+/*
+ * Define this if things work differently on an i386 and an i486:
+ * it will (on an i486) warn about kernel memory accesses that are
+ * done without a 'access_ok(VERIFY_WRITE,..)'
+ */
+#undef TEST_ACCESS_OK
+
+#ifdef CONFIG_X86_PAE
+# include <asm/pgtable-3level.h>
+#else
+# include <asm/pgtable-2level.h>
+#endif
+
+#if defined(CONFIG_HIGHPTE)
+#define pte_offset_map(dir, address)					\
+	((pte_t *)kmap_atomic(pmd_page(*(dir))) +		\
+	 pte_index((address)))
+#define pte_unmap(pte) kunmap_atomic((pte))
+#else
+#define pte_offset_map(dir, address)					\
+	((pte_t *)page_address(pmd_page(*(dir))) + pte_index((address)))
+#define pte_unmap(pte) do { } while (0)
+#endif
+
+/* Clear a kernel PTE and flush it from the TLB */
+#define kpte_clear_flush(ptep, vaddr)		\
+do {						\
+	pte_clear(&init_mm, (vaddr), (ptep));	\
+	__flush_tlb_one_kernel((vaddr));		\
+} while (0)
+
+#endif /* !__ASSEMBLY__ */
+
+/*
+ * kern_addr_valid() is (1) for FLATMEM and (0) for
+ * SPARSEMEM and DISCONTIGMEM
+ */
+#ifdef CONFIG_FLATMEM
+#define kern_addr_valid(addr)	(1)
+#else
+#define kern_addr_valid(kaddr)	(0)
+#endif
+
+/*
+ * This is how much memory in addition to the memory covered up to
+ * and including _end we need mapped initially.
+ * We need:
+ *     (KERNEL_IMAGE_SIZE/4096) / 1024 pages (worst case, non PAE)
+ *     (KERNEL_IMAGE_SIZE/4096) / 512 + 4 pages (worst case for PAE)
+ *
+ * Modulo rounding, each megabyte assigned here requires a kilobyte of
+ * memory, which is currently unreclaimed.
+ *
+ * This should be a multiple of a page.
+ *
+ * KERNEL_IMAGE_SIZE should be greater than pa(_end)
+ * and small than max_low_pfn, otherwise will waste some page table entries
+ */
+#if PTRS_PER_PMD > 1
+#define PAGE_TABLE_SIZE(pages) (((pages) / PTRS_PER_PMD) + PTRS_PER_PGD)
+#else
+#define PAGE_TABLE_SIZE(pages) ((pages) / PTRS_PER_PGD)
+#endif
+
+/*
+ * Number of possible pages in the lowmem region.
+ *
+ * We shift 2 by 31 instead of 1 by 32 to the left in order to avoid a
+ * gas warning about overflowing shift count when gas has been compiled
+ * with only a host target support using a 32-bit type for internal
+ * representation.
+ */
+#define LOWMEM_PAGES ((((_ULL(2)<<31) - __PAGE_OFFSET) >> PAGE_SHIFT))
+
+#endif /* _ASM_X86_PGTABLE_32_H */