1 files changed, 149 insertions, 0 deletions
diff --git a/arch/arm/include/asm/pgalloc.h b/arch/arm/include/asm/pgalloc.h
new file mode 100644
index 0000000000..a17f01235c
--- /dev/null
+++ b/arch/arm/include/asm/pgalloc.h
@@ -0,0 +1,149 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ *  arch/arm/include/asm/pgalloc.h
+ *
+ *  Copyright (C) 2000-2001 Russell King
+ */
+#ifndef _ASMARM_PGALLOC_H
+#define _ASMARM_PGALLOC_H
+
+#include <linux/pagemap.h>
+
+#include <asm/domain.h>
+#include <asm/pgtable-hwdef.h>
+#include <asm/processor.h>
+#include <asm/cacheflush.h>
+#include <asm/tlbflush.h>
+
+#ifdef CONFIG_MMU
+
+#define _PAGE_USER_TABLE	(PMD_TYPE_TABLE | PMD_BIT4 | PMD_DOMAIN(DOMAIN_USER))
+#define _PAGE_KERNEL_TABLE	(PMD_TYPE_TABLE | PMD_BIT4 | PMD_DOMAIN(DOMAIN_KERNEL))
+
+#ifdef CONFIG_ARM_LPAE
+#define PGD_SIZE		(PTRS_PER_PGD * sizeof(pgd_t))
+
+static inline void pud_populate(struct mm_struct *mm, pud_t *pud, pmd_t *pmd)
+{
+	set_pud(pud, __pud(__pa(pmd) | PMD_TYPE_TABLE));
+}
+
+#else	/* !CONFIG_ARM_LPAE */
+#define PGD_SIZE		(PAGE_SIZE << 2)
+
+/*
+ * Since we have only two-level page tables, these are trivial
+ */
+#define pmd_alloc_one(mm,addr)		({ BUG(); ((pmd_t *)2); })
+#define pmd_free(mm, pmd)		do { } while (0)
+#ifdef CONFIG_KASAN
+/* The KASan core unconditionally calls pud_populate() on all architectures */
+#define pud_populate(mm,pmd,pte)	do { } while (0)
+#else
+#define pud_populate(mm,pmd,pte)	BUG()
+#endif
+#endif	/* CONFIG_ARM_LPAE */
+
+extern pgd_t *pgd_alloc(struct mm_struct *mm);
+extern void pgd_free(struct mm_struct *mm, pgd_t *pgd);
+
+static inline void clean_pte_table(pte_t *pte)
+{
+	clean_dcache_area(pte + PTE_HWTABLE_PTRS, PTE_HWTABLE_SIZE);
+}
+
+/*
+ * Allocate one PTE table.
+ *
+ * This actually allocates two hardware PTE tables, but we wrap this up
+ * into one table thus:
+ *
+ *  +------------+
+ *  | Linux pt 0 |
+ *  +------------+
+ *  | Linux pt 1 |
+ *  +------------+
+ *  |  h/w pt 0  |
+ *  +------------+
+ *  |  h/w pt 1  |
+ *  +------------+
+ */
+
+#define __HAVE_ARCH_PTE_ALLOC_ONE_KERNEL
+#define __HAVE_ARCH_PTE_ALLOC_ONE
+#define __HAVE_ARCH_PGD_FREE
+#include <asm-generic/pgalloc.h>
+
+static inline pte_t *
+pte_alloc_one_kernel(struct mm_struct *mm)
+{
+	pte_t *pte = __pte_alloc_one_kernel(mm);
+
+	if (pte)
+		clean_pte_table(pte);
+
+	return pte;
+}
+
+#ifdef CONFIG_HIGHPTE
+#define PGTABLE_HIGHMEM __GFP_HIGHMEM
+#else
+#define PGTABLE_HIGHMEM 0
+#endif
+
+static inline pgtable_t
+pte_alloc_one(struct mm_struct *mm)
+{
+	struct page *pte;
+
+	pte = __pte_alloc_one(mm, GFP_PGTABLE_USER | PGTABLE_HIGHMEM);
+	if (!pte)
+		return NULL;
+	if (!PageHighMem(pte))
+		clean_pte_table(page_address(pte));
+	return pte;
+}
+
+static inline void __pmd_populate(pmd_t *pmdp, phys_addr_t pte,
+				  pmdval_t prot)
+{
+	pmdval_t pmdval = (pte + PTE_HWTABLE_OFF) | prot;
+	pmdp[0] = __pmd(pmdval);
+#ifndef CONFIG_ARM_LPAE
+	pmdp[1] = __pmd(pmdval + 256 * sizeof(pte_t));
+#endif
+	flush_pmd_entry(pmdp);
+}
+
+/*
+ * Populate the pmdp entry with a pointer to the pte.  This pmd is part
+ * of the mm address space.
+ *
+ * Ensure that we always set both PMD entries.
+ */
+static inline void
+pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmdp, pte_t *ptep)
+{
+	/*
+	 * The pmd must be loaded with the physical address of the PTE table
+	 */
+	__pmd_populate(pmdp, __pa(ptep), _PAGE_KERNEL_TABLE);
+}
+
+static inline void
+pmd_populate(struct mm_struct *mm, pmd_t *pmdp, pgtable_t ptep)
+{
+	extern pmdval_t user_pmd_table;
+	pmdval_t prot;
+
+	if (__LINUX_ARM_ARCH__ >= 6 && !IS_ENABLED(CONFIG_ARM_LPAE))
+		prot = user_pmd_table;
+	else
+		prot = _PAGE_USER_TABLE;
+
+	__pmd_populate(pmdp, page_to_phys(ptep), prot);
+}
+
+#endif /* CONFIG_MMU */
+
+#endif