1 files changed, 95 insertions, 0 deletions
diff --git a/arch/arc/include/asm/pgtable-levels.h b/arch/arc/include/asm/pgtable-levels.h
new file mode 100644
index 000000000000..e65fb8c9da12
--- /dev/null
+++ b/arch/arc/include/asm/pgtable-levels.h
@@ -0,0 +1,95 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2020 Synopsys, Inc. (www.synopsys.com)
+ */
+
+/*
+ * Helpers for implemenintg paging levels
+ */
+
+#ifndef _ASM_ARC_PGTABLE_LEVELS_H
+#define _ASM_ARC_PGTABLE_LEVELS_H
+
+/*
+ * 2 level paging setup for software walked MMUv3 (ARC700) and MMUv4 (HS)
+ *
+ * [31]            32 bit virtual address              [0]
+ * -------------------------------------------------------
+ * |               | <---------- PGDIR_SHIFT ----------> |
+ * |               |                | <-- PAGE_SHIFT --> |
+ * -------------------------------------------------------
+ *       |                  |                |
+ *       |                  |                --> off in page frame
+ *       |                  ---> index into Page Table
+ *       ----> index into Page Directory
+ *
+ * Given software walk, the vaddr split is arbitrary set to 11:8:13
+ * However enabling of super page in a 2 level regime pegs PGDIR_SHIFT to
+ * super page size.
+ */
+
+#if defined(CONFIG_ARC_HUGEPAGE_16M)
+#define PGDIR_SHIFT		24
+#elif defined(CONFIG_ARC_HUGEPAGE_2M)
+#define PGDIR_SHIFT		21
+#else
+/*
+ * No Super page case
+ * Default value provides 11:8:13 (8K), 11:9:12 (4K)
+ */
+#define PGDIR_SHIFT		21
+
+#endif
+
+#define PGDIR_SIZE		BIT(PGDIR_SHIFT)	/* vaddr span, not PDG sz */
+#define PGDIR_MASK		(~(PGDIR_SIZE - 1))
+
+#define PTRS_PER_PGD		BIT(32 - PGDIR_SHIFT)
+
+#define PTRS_PER_PTE		BIT(PGDIR_SHIFT - PAGE_SHIFT)
+
+#ifndef __ASSEMBLY__
+
+#include <asm-generic/pgtable-nopmd.h>
+
+/*
+ * 1st level paging: pgd
+ */
+#define pgd_index(addr)		((addr) >> PGDIR_SHIFT)
+#define pgd_offset(mm, addr)	(((mm)->pgd) + pgd_index(addr))
+#define pgd_offset_k(addr)	pgd_offset(&init_mm, addr)
+#define pgd_ERROR(e) \
+	pr_crit("%s:%d: bad pgd %08lx.\n", __FILE__, __LINE__, pgd_val(e))
+
+/*
+ * Due to the strange way generic pgtable level folding works, in a 2 level
+ * setup, pmd_val() returns pgd, so these pmd_* macros actually work on pgd
+ */
+#define pmd_none(x)		(!pmd_val(x))
+#define pmd_bad(x)		((pmd_val(x) & ~PAGE_MASK))
+#define pmd_present(x)		(pmd_val(x))
+#define pmd_clear(xp)		do { pmd_val(*(xp)) = 0; } while (0)
+#define pmd_page_vaddr(pmd)	(pmd_val(pmd) & PAGE_MASK)
+#define pmd_page(pmd)		virt_to_page(pmd_page_vaddr(pmd))
+#define set_pmd(pmdp, pmd)	(*(pmdp) = pmd)
+#define pmd_pgtable(pmd)	((pgtable_t) pmd_page_vaddr(pmd))
+
+#define pte_ERROR(e) \
+	pr_crit("%s:%d: bad pte %08lx.\n", __FILE__, __LINE__, pte_val(e))
+
+#define pte_none(x)		(!pte_val(x))
+#define pte_present(x)		(pte_val(x) & _PAGE_PRESENT)
+#define pte_clear(mm,addr,ptep)	set_pte_at(mm, addr, ptep, __pte(0))
+#define pte_page(pte)		pfn_to_page(pte_pfn(pte))
+#define set_pte(ptep, pte)	((*(ptep)) = (pte))
+#define pte_pfn(pte)		(pte_val(pte) >> PAGE_SHIFT)
+#define pfn_pte(pfn, prot)	__pte(__pfn_to_phys(pfn) | pgprot_val(prot))
+#define mk_pte(page, prot)	pfn_pte(page_to_pfn(page), prot)
+
+#ifdef CONFIG_ISA_ARCV2
+#define pmd_leaf(x)		(pmd_val(x) & _PAGE_HW_SZ)
+#endif
+
+#endif	/* !__ASSEMBLY__ */
+
+#endif