v4.19.13 snapshot.
diff --git a/arch/arc/include/asm/pgtable.h b/arch/arc/include/asm/pgtable.h
new file mode 100644
index 0000000..cf4be70
--- /dev/null
+++ b/arch/arc/include/asm/pgtable.h
@@ -0,0 +1,408 @@
+/*
+ * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * vineetg: May 2011
+ * -Folded PAGE_PRESENT (used by VM) and PAGE_VALID (used by MMU) into 1.
+ * They are semantically the same although in different contexts
+ * VALID marks a TLB entry exists and it will only happen if PRESENT
+ * - Utilise some unused free bits to confine PTE flags to 12 bits
+ * This is a must for 4k pg-sz
+ *
+ * vineetg: Mar 2011 - changes to accommodate MMU TLB Page Descriptor mods
+ * -TLB Locking never really existed, except for initial specs
+ * -SILENT_xxx not needed for our port
+ * -Per my request, MMU V3 changes the layout of some of the bits
+ * to avoid a few shifts in TLB Miss handlers.
+ *
+ * vineetg: April 2010
+ * -PGD entry no longer contains any flags. If empty it is 0, otherwise has
+ * Pg-Tbl ptr. Thus pmd_present(), pmd_valid(), pmd_set( ) become simpler
+ *
+ * vineetg: April 2010
+ * -Switched form 8:11:13 split for page table lookup to 11:8:13
+ * -this speeds up page table allocation itself as we now have to memset 1K
+ * instead of 8k per page table.
+ * -TODO: Right now page table alloc is 8K and rest 7K is unused
+ * need to optimise it
+ *
+ * Amit Bhor, Sameer Dhavale: Codito Technologies 2004
+ */
+
+#ifndef _ASM_ARC_PGTABLE_H
+#define _ASM_ARC_PGTABLE_H
+
+#include <linux/const.h>
+#define __ARCH_USE_5LEVEL_HACK
+#include <asm-generic/pgtable-nopmd.h>
+#include <asm/page.h>
+#include <asm/mmu.h> /* to propagate CONFIG_ARC_MMU_VER <n> */
+
+/**************************************************************************
+ * Page Table Flags
+ *
+ * ARC700 MMU only deals with softare managed TLB entries.
+ * Page Tables are purely for Linux VM's consumption and the bits below are
+ * suited to that (uniqueness). Hence some are not implemented in the TLB and
+ * some have different value in TLB.
+ * e.g. MMU v2: K_READ bit is 8 and so is GLOBAL (possible because they live in
+ * seperate PD0 and PD1, which combined forms a translation entry)
+ * while for PTE perspective, they are 8 and 9 respectively
+ * with MMU v3: Most bits (except SHARED) represent the exact hardware pos
+ * (saves some bit shift ops in TLB Miss hdlrs)
+ */
+
+#if (CONFIG_ARC_MMU_VER <= 2)
+
+#define _PAGE_ACCESSED (1<<1) /* Page is accessed (S) */
+#define _PAGE_CACHEABLE (1<<2) /* Page is cached (H) */
+#define _PAGE_EXECUTE (1<<3) /* Page has user execute perm (H) */
+#define _PAGE_WRITE (1<<4) /* Page has user write perm (H) */
+#define _PAGE_READ (1<<5) /* Page has user read perm (H) */
+#define _PAGE_DIRTY (1<<6) /* Page modified (dirty) (S) */
+#define _PAGE_SPECIAL (1<<7)
+#define _PAGE_GLOBAL (1<<8) /* Page is global (H) */
+#define _PAGE_PRESENT (1<<10) /* TLB entry is valid (H) */
+
+#else /* MMU v3 onwards */
+
+#define _PAGE_CACHEABLE (1<<0) /* Page is cached (H) */
+#define _PAGE_EXECUTE (1<<1) /* Page has user execute perm (H) */
+#define _PAGE_WRITE (1<<2) /* Page has user write perm (H) */
+#define _PAGE_READ (1<<3) /* Page has user read perm (H) */
+#define _PAGE_ACCESSED (1<<4) /* Page is accessed (S) */
+#define _PAGE_DIRTY (1<<5) /* Page modified (dirty) (S) */
+#define _PAGE_SPECIAL (1<<6)
+
+#if (CONFIG_ARC_MMU_VER >= 4)
+#define _PAGE_WTHRU (1<<7) /* Page cache mode write-thru (H) */
+#endif
+
+#define _PAGE_GLOBAL (1<<8) /* Page is global (H) */
+#define _PAGE_PRESENT (1<<9) /* TLB entry is valid (H) */
+
+#if (CONFIG_ARC_MMU_VER >= 4)
+#define _PAGE_HW_SZ (1<<10) /* Page Size indicator (H): 0 normal, 1 super */
+#endif
+
+#define _PAGE_SHARED_CODE (1<<11) /* Shared Code page with cmn vaddr
+ usable for shared TLB entries (H) */
+
+#define _PAGE_UNUSED_BIT (1<<12)
+#endif
+
+/* vmalloc permissions */
+#define _K_PAGE_PERMS (_PAGE_EXECUTE | _PAGE_WRITE | _PAGE_READ | \
+ _PAGE_GLOBAL | _PAGE_PRESENT)
+
+#ifndef CONFIG_ARC_CACHE_PAGES
+#undef _PAGE_CACHEABLE
+#define _PAGE_CACHEABLE 0
+#endif
+
+#ifndef _PAGE_HW_SZ
+#define _PAGE_HW_SZ 0
+#endif
+
+/* Defaults for every user page */
+#define ___DEF (_PAGE_PRESENT | _PAGE_CACHEABLE)
+
+/* Set of bits not changed in pte_modify */
+#define _PAGE_CHG_MASK (PAGE_MASK | _PAGE_ACCESSED | _PAGE_DIRTY | _PAGE_SPECIAL)
+
+/* More Abbrevaited helpers */
+#define PAGE_U_NONE __pgprot(___DEF)
+#define PAGE_U_R __pgprot(___DEF | _PAGE_READ)
+#define PAGE_U_W_R __pgprot(___DEF | _PAGE_READ | _PAGE_WRITE)
+#define PAGE_U_X_R __pgprot(___DEF | _PAGE_READ | _PAGE_EXECUTE)
+#define PAGE_U_X_W_R __pgprot(___DEF | _PAGE_READ | _PAGE_WRITE | \
+ _PAGE_EXECUTE)
+
+#define PAGE_SHARED PAGE_U_W_R
+
+/* While kernel runs out of unstranslated space, vmalloc/modules use a chunk of
+ * user vaddr space - visible in all addr spaces, but kernel mode only
+ * Thus Global, all-kernel-access, no-user-access, cached
+ */
+#define PAGE_KERNEL __pgprot(_K_PAGE_PERMS | _PAGE_CACHEABLE)
+
+/* ioremap */
+#define PAGE_KERNEL_NO_CACHE __pgprot(_K_PAGE_PERMS)
+
+/* Masks for actual TLB "PD"s */
+#define PTE_BITS_IN_PD0 (_PAGE_GLOBAL | _PAGE_PRESENT | _PAGE_HW_SZ)
+#define PTE_BITS_RWX (_PAGE_EXECUTE | _PAGE_WRITE | _PAGE_READ)
+
+#ifdef CONFIG_ARC_HAS_PAE40
+#define PTE_BITS_NON_RWX_IN_PD1 (0xff00000000 | PAGE_MASK | _PAGE_CACHEABLE)
+#else
+#define PTE_BITS_NON_RWX_IN_PD1 (PAGE_MASK | _PAGE_CACHEABLE)
+#endif
+
+/**************************************************************************
+ * Mapping of vm_flags (Generic VM) to PTE flags (arch specific)
+ *
+ * Certain cases have 1:1 mapping
+ * e.g. __P101 means VM_READ, VM_EXEC and !VM_SHARED
+ * which directly corresponds to PAGE_U_X_R
+ *
+ * Other rules which cause the divergence from 1:1 mapping
+ *
+ * 1. Although ARC700 can do exclusive execute/write protection (meaning R
+ * can be tracked independet of X/W unlike some other CPUs), still to
+ * keep things consistent with other archs:
+ * -Write implies Read: W => R
+ * -Execute implies Read: X => R
+ *
+ * 2. Pvt Writable doesn't have Write Enabled initially: Pvt-W => !W
+ * This is to enable COW mechanism
+ */
+ /* xwr */
+#define __P000 PAGE_U_NONE
+#define __P001 PAGE_U_R
+#define __P010 PAGE_U_R /* Pvt-W => !W */
+#define __P011 PAGE_U_R /* Pvt-W => !W */
+#define __P100 PAGE_U_X_R /* X => R */
+#define __P101 PAGE_U_X_R
+#define __P110 PAGE_U_X_R /* Pvt-W => !W and X => R */
+#define __P111 PAGE_U_X_R /* Pvt-W => !W */
+
+#define __S000 PAGE_U_NONE
+#define __S001 PAGE_U_R
+#define __S010 PAGE_U_W_R /* W => R */
+#define __S011 PAGE_U_W_R
+#define __S100 PAGE_U_X_R /* X => R */
+#define __S101 PAGE_U_X_R
+#define __S110 PAGE_U_X_W_R /* X => R */
+#define __S111 PAGE_U_X_W_R
+
+/****************************************************************
+ * 2 tier (PGD:PTE) software page walker
+ *
+ * [31] 32 bit virtual address [0]
+ * -------------------------------------------------------
+ * | | <------------ PGDIR_SHIFT ----------> |
+ * | | |
+ * | BITS_FOR_PGD | BITS_FOR_PTE | <-- PAGE_SHIFT --> |
+ * -------------------------------------------------------
+ * | | |
+ * | | --> off in page frame
+ * | ---> index into Page Table
+ * ----> index into Page Directory
+ *
+ * In a single page size configuration, only PAGE_SHIFT is fixed
+ * So both PGD and PTE sizing can be tweaked
+ * e.g. 8K page (PAGE_SHIFT 13) can have
+ * - PGDIR_SHIFT 21 -> 11:8:13 address split
+ * - PGDIR_SHIFT 24 -> 8:11:13 address split
+ *
+ * If Super Page is configured, PGDIR_SHIFT becomes fixed too,
+ * so the sizing flexibility is gone.
+ */
+
+#if defined(CONFIG_ARC_HUGEPAGE_16M)
+#define PGDIR_SHIFT 24
+#elif defined(CONFIG_ARC_HUGEPAGE_2M)
+#define PGDIR_SHIFT 21
+#else
+/*
+ * Only Normal page support so "hackable" (see comment above)
+ * Default value provides 11:8:13 (8K), 11:9:12 (4K)
+ */
+#define PGDIR_SHIFT 21
+#endif
+
+#define BITS_FOR_PTE (PGDIR_SHIFT - PAGE_SHIFT)
+#define BITS_FOR_PGD (32 - PGDIR_SHIFT)
+
+#define PGDIR_SIZE _BITUL(PGDIR_SHIFT) /* vaddr span, not PDG sz */
+#define PGDIR_MASK (~(PGDIR_SIZE-1))
+
+#define PTRS_PER_PTE _BITUL(BITS_FOR_PTE)
+#define PTRS_PER_PGD _BITUL(BITS_FOR_PGD)
+
+/*
+ * Number of entries a user land program use.
+ * TASK_SIZE is the maximum vaddr that can be used by a userland program.
+ */
+#define USER_PTRS_PER_PGD (TASK_SIZE / PGDIR_SIZE)
+
+/*
+ * No special requirements for lowest virtual address we permit any user space
+ * mapping to be mapped at.
+ */
+#define FIRST_USER_ADDRESS 0UL
+
+
+/****************************************************************
+ * Bucket load of VM Helpers
+ */
+
+#ifndef __ASSEMBLY__
+
+#define pte_ERROR(e) \
+ pr_crit("%s:%d: bad pte %08lx.\n", __FILE__, __LINE__, pte_val(e))
+#define pgd_ERROR(e) \
+ pr_crit("%s:%d: bad pgd %08lx.\n", __FILE__, __LINE__, pgd_val(e))
+
+/* the zero page used for uninitialized and anonymous pages */
+extern char empty_zero_page[PAGE_SIZE];
+#define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page))
+
+#define pte_unmap(pte) do { } while (0)
+#define pte_unmap_nested(pte) do { } while (0)
+
+#define set_pte(pteptr, pteval) ((*(pteptr)) = (pteval))
+#define set_pmd(pmdptr, pmdval) (*(pmdptr) = pmdval)
+
+/* find the page descriptor of the Page Tbl ref by PMD entry */
+#define pmd_page(pmd) virt_to_page(pmd_val(pmd) & PAGE_MASK)
+
+/* find the logical addr (phy for ARC) of the Page Tbl ref by PMD entry */
+#define pmd_page_vaddr(pmd) (pmd_val(pmd) & PAGE_MASK)
+
+/* In a 2 level sys, setup the PGD entry with PTE value */
+static inline void pmd_set(pmd_t *pmdp, pte_t *ptep)
+{
+ pmd_val(*pmdp) = (unsigned long)ptep;
+}
+
+#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 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 pte_page(pte) pfn_to_page(pte_pfn(pte))
+#define mk_pte(page, prot) pfn_pte(page_to_pfn(page), prot)
+#define pfn_pte(pfn, prot) __pte(__pfn_to_phys(pfn) | pgprot_val(prot))
+
+/* Don't use virt_to_pfn for macros below: could cause truncations for PAE40*/
+#define pte_pfn(pte) (pte_val(pte) >> PAGE_SHIFT)
+#define __pte_index(addr) (((addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
+
+/*
+ * pte_offset gets a @ptr to PMD entry (PGD in our 2-tier paging system)
+ * and returns ptr to PTE entry corresponding to @addr
+ */
+#define pte_offset(dir, addr) ((pte_t *)(pmd_page_vaddr(*dir)) +\
+ __pte_index(addr))
+
+/* No mapping of Page Tables in high mem etc, so following same as above */
+#define pte_offset_kernel(dir, addr) pte_offset(dir, addr)
+#define pte_offset_map(dir, addr) pte_offset(dir, addr)
+
+/* Zoo of pte_xxx function */
+#define pte_read(pte) (pte_val(pte) & _PAGE_READ)
+#define pte_write(pte) (pte_val(pte) & _PAGE_WRITE)
+#define pte_dirty(pte) (pte_val(pte) & _PAGE_DIRTY)
+#define pte_young(pte) (pte_val(pte) & _PAGE_ACCESSED)
+#define pte_special(pte) (pte_val(pte) & _PAGE_SPECIAL)
+
+#define PTE_BIT_FUNC(fn, op) \
+ static inline pte_t pte_##fn(pte_t pte) { pte_val(pte) op; return pte; }
+
+PTE_BIT_FUNC(mknotpresent, &= ~(_PAGE_PRESENT));
+PTE_BIT_FUNC(wrprotect, &= ~(_PAGE_WRITE));
+PTE_BIT_FUNC(mkwrite, |= (_PAGE_WRITE));
+PTE_BIT_FUNC(mkclean, &= ~(_PAGE_DIRTY));
+PTE_BIT_FUNC(mkdirty, |= (_PAGE_DIRTY));
+PTE_BIT_FUNC(mkold, &= ~(_PAGE_ACCESSED));
+PTE_BIT_FUNC(mkyoung, |= (_PAGE_ACCESSED));
+PTE_BIT_FUNC(exprotect, &= ~(_PAGE_EXECUTE));
+PTE_BIT_FUNC(mkexec, |= (_PAGE_EXECUTE));
+PTE_BIT_FUNC(mkspecial, |= (_PAGE_SPECIAL));
+PTE_BIT_FUNC(mkhuge, |= (_PAGE_HW_SZ));
+
+static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
+{
+ return __pte((pte_val(pte) & _PAGE_CHG_MASK) | pgprot_val(newprot));
+}
+
+/* Macro to mark a page protection as uncacheable */
+#define pgprot_noncached(prot) (__pgprot(pgprot_val(prot) & ~_PAGE_CACHEABLE))
+
+static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
+ pte_t *ptep, pte_t pteval)
+{
+ set_pte(ptep, pteval);
+}
+
+/*
+ * All kernel related VM pages are in init's mm.
+ */
+#define pgd_offset_k(address) pgd_offset(&init_mm, address)
+#define pgd_index(addr) ((addr) >> PGDIR_SHIFT)
+#define pgd_offset(mm, addr) (((mm)->pgd)+pgd_index(addr))
+
+/*
+ * Macro to quickly access the PGD entry, utlising the fact that some
+ * arch may cache the pointer to Page Directory of "current" task
+ * in a MMU register
+ *
+ * Thus task->mm->pgd (3 pointer dereferences, cache misses etc simply
+ * becomes read a register
+ *
+ * ********CAUTION*******:
+ * Kernel code might be dealing with some mm_struct of NON "current"
+ * Thus use this macro only when you are certain that "current" is current
+ * e.g. when dealing with signal frame setup code etc
+ */
+#ifndef CONFIG_SMP
+#define pgd_offset_fast(mm, addr) \
+({ \
+ pgd_t *pgd_base = (pgd_t *) read_aux_reg(ARC_REG_SCRATCH_DATA0); \
+ pgd_base + pgd_index(addr); \
+})
+#else
+#define pgd_offset_fast(mm, addr) pgd_offset(mm, addr)
+#endif
+
+extern pgd_t swapper_pg_dir[] __aligned(PAGE_SIZE);
+void update_mmu_cache(struct vm_area_struct *vma, unsigned long address,
+ pte_t *ptep);
+
+/* Encode swap {type,off} tuple into PTE
+ * We reserve 13 bits for 5-bit @type, keeping bits 12-5 zero, ensuring that
+ * PAGE_PRESENT is zero in a PTE holding swap "identifier"
+ */
+#define __swp_entry(type, off) ((swp_entry_t) { \
+ ((type) & 0x1f) | ((off) << 13) })
+
+/* Decode a PTE containing swap "identifier "into constituents */
+#define __swp_type(pte_lookalike) (((pte_lookalike).val) & 0x1f)
+#define __swp_offset(pte_lookalike) ((pte_lookalike).val >> 13)
+
+/* NOPs, to keep generic kernel happy */
+#define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) })
+#define __swp_entry_to_pte(x) ((pte_t) { (x).val })
+
+#define kern_addr_valid(addr) (1)
+
+/*
+ * remap a physical page `pfn' of size `size' with page protection `prot'
+ * into virtual address `from'
+ */
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+#include <asm/hugepage.h>
+#endif
+
+#include <asm-generic/pgtable.h>
+
+/* to cope with aliasing VIPT cache */
+#define HAVE_ARCH_UNMAPPED_AREA
+
+/*
+ * No page table caches to initialise
+ */
+#define pgtable_cache_init() do { } while (0)
+
+#endif /* __ASSEMBLY__ */
+
+#endif