/* SPDX-License-Identifier: GPL-2.0 */
/*
 *  S390 version
 *    Copyright IBM Corp. 1999, 2000
 *    Author(s): Hartmut Penner (hp@de.ibm.com)
 *               Ulrich Weigand (weigand@de.ibm.com)
 *               Martin Schwidefsky (schwidefsky@de.ibm.com)
 *
 *  Derived from "include/asm-i386/pgtable.h"
 */

#ifndef _ASM_S390_PGTABLE_H
#define _ASM_S390_PGTABLE_H

#include <linux/sched.h>
#include <linux/mm_types.h>
#include <linux/page-flags.h>
#include <linux/radix-tree.h>
#include <linux/atomic.h>
#include <asm/bug.h>
#include <asm/page.h>
#include <asm/uv.h>

extern pgd_t swapper_pg_dir[];
extern void paging_init(void);
extern unsigned long s390_invalid_asce;

enum {
        PG_DIRECT_MAP_4K = 0,
        PG_DIRECT_MAP_1M,
        PG_DIRECT_MAP_2G,
        PG_DIRECT_MAP_MAX
};

extern atomic_long_t direct_pages_count[PG_DIRECT_MAP_MAX];

static inline void update_page_count(int level, long count)
{
        if (IS_ENABLED(CONFIG_PROC_FS))
                atomic_long_add(count, &direct_pages_count[level]);
}

struct seq_file;
void arch_report_meminfo(struct seq_file *m);

/*
 * The S390 doesn't have any external MMU info: the kernel page
 * tables contain all the necessary information.
 */
#define update_mmu_cache(vma, address, ptep)     do { } while (0)
#define update_mmu_cache_pmd(vma, address, ptep) do { } while (0)

/*
 * ZERO_PAGE is a global shared page that is always zero; used
 * for zero-mapped memory areas etc..
 */

extern unsigned long empty_zero_page;
extern unsigned long zero_page_mask;

#define ZERO_PAGE(vaddr) \
        (virt_to_page((void *)(empty_zero_page + \
         (((unsigned long)(vaddr)) &zero_page_mask))))
#define __HAVE_COLOR_ZERO_PAGE

/* TODO: s390 cannot support io_remap_pfn_range... */

#define FIRST_USER_ADDRESS  0UL

#define pte_ERROR(e) \
        printk("%s:%d: bad pte %p.\n", __FILE__, __LINE__, (void *) pte_val(e))
#define pmd_ERROR(e) \
        printk("%s:%d: bad pmd %p.\n", __FILE__, __LINE__, (void *) pmd_val(e))
#define pud_ERROR(e) \
        printk("%s:%d: bad pud %p.\n", __FILE__, __LINE__, (void *) pud_val(e))
#define p4d_ERROR(e) \
        printk("%s:%d: bad p4d %p.\n", __FILE__, __LINE__, (void *) p4d_val(e))
#define pgd_ERROR(e) \
        printk("%s:%d: bad pgd %p.\n", __FILE__, __LINE__, (void *) pgd_val(e))

/*
 * The vmalloc and module area will always be on the topmost area of the
 * kernel mapping. 512GB are reserved for vmalloc by default.
 * At the top of the vmalloc area a 2GB area is reserved where modules
 * will reside. That makes sure that inter module branches always
 * happen without trampolines and in addition the placement within a
 * 2GB frame is branch prediction unit friendly.
 */
extern unsigned long VMALLOC_START;
extern unsigned long VMALLOC_END;
#define VMALLOC_DEFAULT_SIZE    ((512UL << 30) - MODULES_LEN)
extern struct page *vmemmap;
extern unsigned long vmemmap_size;

#define VMEM_MAX_PHYS ((unsigned long) vmemmap)

extern unsigned long MODULES_VADDR;
extern unsigned long MODULES_END;
#define MODULES_VADDR   MODULES_VADDR
#define MODULES_END     MODULES_END
#define MODULES_LEN     (1UL << 31)

static inline int is_module_addr(void *addr)
{
        BUILD_BUG_ON(MODULES_LEN > (1UL << 31));
        if (addr < (void *)MODULES_VADDR)
                return 0;
        if (addr > (void *)MODULES_END)
                return 0;
        return 1;
}

/*
 * A 64 bit pagetable entry of S390 has following format:
 * |                     PFRA                         |0IPC|  OS  |
 * 0000000000111111111122222222223333333333444444444455555555556666
 * 0123456789012345678901234567890123456789012345678901234567890123
 *
 * I Page-Invalid Bit:    Page is not available for address-translation
 * P Page-Protection Bit: Store access not possible for page
 * C Change-bit override: HW is not required to set change bit
 *
 * A 64 bit segmenttable entry of S390 has following format:
 * |        P-table origin                              |      TT
 * 0000000000111111111122222222223333333333444444444455555555556666
 * 0123456789012345678901234567890123456789012345678901234567890123
 *
 * I Segment-Invalid Bit:    Segment is not available for address-translation
 * C Common-Segment Bit:     Segment is not private (PoP 3-30)
 * P Page-Protection Bit: Store access not possible for page
 * TT Type 00
 *
 * A 64 bit region table entry of S390 has following format:
 * |        S-table origin                             |   TF  TTTL
 * 0000000000111111111122222222223333333333444444444455555555556666
 * 0123456789012345678901234567890123456789012345678901234567890123
 *
 * I Segment-Invalid Bit:    Segment is not available for address-translation
 * TT Type 01
 * TF
 * TL Table length
 *
 * The 64 bit regiontable origin of S390 has following format:
 * |      region table origon                          |       DTTL
 * 0000000000111111111122222222223333333333444444444455555555556666
 * 0123456789012345678901234567890123456789012345678901234567890123
 *
 * X Space-Switch event:
 * G Segment-Invalid Bit:  
 * P Private-Space Bit:    
 * S Storage-Alteration:
 * R Real space
 * TL Table-Length:
 *
 * A storage key has the following format:
 * | ACC |F|R|C|0|
 *  0   3 4 5 6 7
 * ACC: access key
 * F  : fetch protection bit
 * R  : referenced bit
 * C  : changed bit
 */

/* Hardware bits in the page table entry */
#define _PAGE_NOEXEC    0x100           /* HW no-execute bit  */
#define _PAGE_PROTECT   0x200           /* HW read-only bit  */
#define _PAGE_INVALID   0x400           /* HW invalid bit    */
#define _PAGE_LARGE     0x800           /* Bit to mark a large pte */

/* Software bits in the page table entry */
#define _PAGE_PRESENT   0x001           /* SW pte present bit */
#define _PAGE_YOUNG     0x004           /* SW pte young bit */
#define _PAGE_DIRTY     0x008           /* SW pte dirty bit */
#define _PAGE_READ      0x010           /* SW pte read bit */
#define _PAGE_WRITE     0x020           /* SW pte write bit */
#define _PAGE_SPECIAL   0x040           /* SW associated with special page */
#define _PAGE_UNUSED    0x080           /* SW bit for pgste usage state */

#ifdef CONFIG_MEM_SOFT_DIRTY
#define _PAGE_SOFT_DIRTY 0x002          /* SW pte soft dirty bit */
#else
#define _PAGE_SOFT_DIRTY 0x000
#endif

/* Set of bits not changed in pte_modify */
#define _PAGE_CHG_MASK          (PAGE_MASK | _PAGE_SPECIAL | _PAGE_DIRTY | \
                                 _PAGE_YOUNG | _PAGE_SOFT_DIRTY)

/*
 * handle_pte_fault uses pte_present and pte_none to find out the pte type
 * WITHOUT holding the page table lock. The _PAGE_PRESENT bit is used to
 * distinguish present from not-present ptes. It is changed only with the page
 * table lock held.
 *
 * The following table gives the different possible bit combinations for
 * the pte hardware and software bits in the last 12 bits of a pte
 * (. unassigned bit, x don't care, t swap type):
 *
 *                              842100000000
 *                              000084210000
 *                              000000008421
 *                              .IR.uswrdy.p
 * empty                        .10.00000000
 * swap                         .11..ttttt.0
 * prot-none, clean, old        .11.xx0000.1
 * prot-none, clean, young      .11.xx0001.1
 * prot-none, dirty, old        .11.xx0010.1
 * prot-none, dirty, young      .11.xx0011.1
 * read-only, clean, old        .11.xx0100.1
 * read-only, clean, young      .01.xx0101.1
 * read-only, dirty, old        .11.xx0110.1
 * read-only, dirty, young      .01.xx0111.1
 * read-write, clean, old       .11.xx1100.1
 * read-write, clean, young     .01.xx1101.1
 * read-write, dirty, old       .10.xx1110.1
 * read-write, dirty, young     .00.xx1111.1
 * HW-bits: R read-only, I invalid
 * SW-bits: p present, y young, d dirty, r read, w write, s special,
 *          u unused, l large
 *
 * pte_none    is true for the bit pattern .10.00000000, pte == 0x400
 * pte_swap    is true for the bit pattern .11..ooooo.0, (pte & 0x201) == 0x200
 * pte_present is true for the bit pattern .xx.xxxxxx.1, (pte & 0x001) == 0x001
 */

/* Bits in the segment/region table address-space-control-element */
#define _ASCE_ORIGIN            ~0xfffUL/* region/segment table origin      */
#define _ASCE_PRIVATE_SPACE     0x100   /* private space control            */
#define _ASCE_ALT_EVENT         0x80    /* storage alteration event control */
#define _ASCE_SPACE_SWITCH      0x40    /* space switch event               */
#define _ASCE_REAL_SPACE        0x20    /* real space control               */
#define _ASCE_TYPE_MASK         0x0c    /* asce table type mask             */
#define _ASCE_TYPE_REGION1      0x0c    /* region first table type          */
#define _ASCE_TYPE_REGION2      0x08    /* region second table type         */
#define _ASCE_TYPE_REGION3      0x04    /* region third table type          */
#define _ASCE_TYPE_SEGMENT      0x00    /* segment table type               */
#define _ASCE_TABLE_LENGTH      0x03    /* region table length              */

/* Bits in the region table entry */
#define _REGION_ENTRY_ORIGIN    ~0xfffUL/* region/segment table origin      */
#define _REGION_ENTRY_PROTECT   0x200   /* region protection bit            */
#define _REGION_ENTRY_NOEXEC    0x100   /* region no-execute bit            */
#define _REGION_ENTRY_OFFSET    0xc0    /* region table offset              */
#define _REGION_ENTRY_INVALID   0x20    /* invalid region table entry       */
#define _REGION_ENTRY_TYPE_MASK 0x0c    /* region table type mask           */
#define _REGION_ENTRY_TYPE_R1   0x0c    /* region first table type          */
#define _REGION_ENTRY_TYPE_R2   0x08    /* region second table type         */
#define _REGION_ENTRY_TYPE_R3   0x04    /* region third table type          */
#define _REGION_ENTRY_LENGTH    0x03    /* region third length              */

#define _REGION1_ENTRY          (_REGION_ENTRY_TYPE_R1 | _REGION_ENTRY_LENGTH)
#define _REGION1_ENTRY_EMPTY    (_REGION_ENTRY_TYPE_R1 | _REGION_ENTRY_INVALID)
#define _REGION2_ENTRY          (_REGION_ENTRY_TYPE_R2 | _REGION_ENTRY_LENGTH)
#define _REGION2_ENTRY_EMPTY    (_REGION_ENTRY_TYPE_R2 | _REGION_ENTRY_INVALID)
#define _REGION3_ENTRY          (_REGION_ENTRY_TYPE_R3 | _REGION_ENTRY_LENGTH)
#define _REGION3_ENTRY_EMPTY    (_REGION_ENTRY_TYPE_R3 | _REGION_ENTRY_INVALID)

#define _REGION3_ENTRY_ORIGIN_LARGE ~0x7fffffffUL /* large page address      */
#define _REGION3_ENTRY_DIRTY    0x2000  /* SW region dirty bit */
#define _REGION3_ENTRY_YOUNG    0x1000  /* SW region young bit */
#define _REGION3_ENTRY_LARGE    0x0400  /* RTTE-format control, large page  */
#define _REGION3_ENTRY_READ     0x0002  /* SW region read bit */
#define _REGION3_ENTRY_WRITE    0x0001  /* SW region write bit */

#ifdef CONFIG_MEM_SOFT_DIRTY
#define _REGION3_ENTRY_SOFT_DIRTY 0x4000 /* SW region soft dirty bit */
#else
#define _REGION3_ENTRY_SOFT_DIRTY 0x0000 /* SW region soft dirty bit */
#endif

#define _REGION_ENTRY_BITS       0xfffffffffffff22fUL

/* Bits in the segment table entry */
#define _SEGMENT_ENTRY_BITS                     0xfffffffffffffe33UL
#define _SEGMENT_ENTRY_HARDWARE_BITS            0xfffffffffffffe30UL
#define _SEGMENT_ENTRY_HARDWARE_BITS_LARGE      0xfffffffffff00730UL
#define _SEGMENT_ENTRY_ORIGIN_LARGE ~0xfffffUL /* large page address        */
#define _SEGMENT_ENTRY_ORIGIN   ~0x7ffUL/* page table origin                */
#define _SEGMENT_ENTRY_PROTECT  0x200   /* segment protection bit           */
#define _SEGMENT_ENTRY_NOEXEC   0x100   /* segment no-execute bit           */
#define _SEGMENT_ENTRY_INVALID  0x20    /* invalid segment table entry      */
#define _SEGMENT_ENTRY_TYPE_MASK 0x0c   /* segment table type mask          */

#define _SEGMENT_ENTRY          (0)
#define _SEGMENT_ENTRY_EMPTY    (_SEGMENT_ENTRY_INVALID)

#define _SEGMENT_ENTRY_DIRTY    0x2000  /* SW segment dirty bit */
#define _SEGMENT_ENTRY_YOUNG    0x1000  /* SW segment young bit */
#define _SEGMENT_ENTRY_LARGE    0x0400  /* STE-format control, large page */
#define _SEGMENT_ENTRY_WRITE    0x0002  /* SW segment write bit */
#define _SEGMENT_ENTRY_READ     0x0001  /* SW segment read bit */

#ifdef CONFIG_MEM_SOFT_DIRTY
#define _SEGMENT_ENTRY_SOFT_DIRTY 0x4000 /* SW segment soft dirty bit */
#else
#define _SEGMENT_ENTRY_SOFT_DIRTY 0x0000 /* SW segment soft dirty bit */
#endif

#define _CRST_ENTRIES   2048    /* number of region/segment table entries */
#define _PAGE_ENTRIES   256     /* number of page table entries */

#define _CRST_TABLE_SIZE (_CRST_ENTRIES * 8)
#define _PAGE_TABLE_SIZE (_PAGE_ENTRIES * 8)

#define _REGION1_SHIFT  53
#define _REGION2_SHIFT  42
#define _REGION3_SHIFT  31
#define _SEGMENT_SHIFT  20

#define _REGION1_INDEX  (0x7ffUL << _REGION1_SHIFT)
#define _REGION2_INDEX  (0x7ffUL << _REGION2_SHIFT)
#define _REGION3_INDEX  (0x7ffUL << _REGION3_SHIFT)
#define _SEGMENT_INDEX  (0x7ffUL << _SEGMENT_SHIFT)
#define _PAGE_INDEX     (0xffUL  << _PAGE_SHIFT)

#define _REGION1_SIZE   (1UL << _REGION1_SHIFT)
#define _REGION2_SIZE   (1UL << _REGION2_SHIFT)
#define _REGION3_SIZE   (1UL << _REGION3_SHIFT)
#define _SEGMENT_SIZE   (1UL << _SEGMENT_SHIFT)

#define _REGION1_MASK   (~(_REGION1_SIZE - 1))
#define _REGION2_MASK   (~(_REGION2_SIZE - 1))
#define _REGION3_MASK   (~(_REGION3_SIZE - 1))
#define _SEGMENT_MASK   (~(_SEGMENT_SIZE - 1))

#define PMD_SHIFT       _SEGMENT_SHIFT
#define PUD_SHIFT       _REGION3_SHIFT
#define P4D_SHIFT       _REGION2_SHIFT
#define PGDIR_SHIFT     _REGION1_SHIFT

#define PMD_SIZE        _SEGMENT_SIZE
#define PUD_SIZE        _REGION3_SIZE
#define P4D_SIZE        _REGION2_SIZE
#define PGDIR_SIZE      _REGION1_SIZE

#define PMD_MASK        _SEGMENT_MASK
#define PUD_MASK        _REGION3_MASK
#define P4D_MASK        _REGION2_MASK
#define PGDIR_MASK      _REGION1_MASK

#define PTRS_PER_PTE    _PAGE_ENTRIES
#define PTRS_PER_PMD    _CRST_ENTRIES
#define PTRS_PER_PUD    _CRST_ENTRIES
#define PTRS_PER_P4D    _CRST_ENTRIES
#define PTRS_PER_PGD    _CRST_ENTRIES

#define MAX_PTRS_PER_P4D        PTRS_PER_P4D

/*
 * Segment table and region3 table entry encoding
 * (R = read-only, I = invalid, y = young bit):
 *                              dy..R...I...wr
 * prot-none, clean, old        00..1...1...00
 * prot-none, clean, young      01..1...1...00
 * prot-none, dirty, old        10..1...1...00
 * prot-none, dirty, young      11..1...1...00
 * read-only, clean, old        00..1...1...01
 * read-only, clean, young      01..1...0...01
 * read-only, dirty, old        10..1...1...01
 * read-only, dirty, young      11..1...0...01
 * read-write, clean, old       00..1...1...11
 * read-write, clean, young     01..1...0...11
 * read-write, dirty, old       10..0...1...11
 * read-write, dirty, young     11..0...0...11
 * The segment table origin is used to distinguish empty (origin==0) from
 * read-write, old segment table entries (origin!=0)
 * HW-bits: R read-only, I invalid
 * SW-bits: y young, d dirty, r read, w write
 */

/* Page status table bits for virtualization */
#define PGSTE_ACC_BITS  0xf000000000000000UL
#define PGSTE_FP_BIT    0x0800000000000000UL
#define PGSTE_PCL_BIT   0x0080000000000000UL
#define PGSTE_HR_BIT    0x0040000000000000UL
#define PGSTE_HC_BIT    0x0020000000000000UL
#define PGSTE_GR_BIT    0x0004000000000000UL
#define PGSTE_GC_BIT    0x0002000000000000UL
#define PGSTE_UC_BIT    0x0000800000000000UL    /* user dirty (migration) */
#define PGSTE_IN_BIT    0x0000400000000000UL    /* IPTE notify bit */
#define PGSTE_VSIE_BIT  0x0000200000000000UL    /* ref'd in a shadow table */

/* Guest Page State used for virtualization */
#define _PGSTE_GPS_ZERO                 0x0000000080000000UL
#define _PGSTE_GPS_NODAT                0x0000000040000000UL
#define _PGSTE_GPS_USAGE_MASK           0x0000000003000000UL
#define _PGSTE_GPS_USAGE_STABLE         0x0000000000000000UL
#define _PGSTE_GPS_USAGE_UNUSED         0x0000000001000000UL
#define _PGSTE_GPS_USAGE_POT_VOLATILE   0x0000000002000000UL
#define _PGSTE_GPS_USAGE_VOLATILE       _PGSTE_GPS_USAGE_MASK

/*
 * A user page table pointer has the space-switch-event bit, the
 * private-space-control bit and the storage-alteration-event-control
 * bit set. A kernel page table pointer doesn't need them.
 */
#define _ASCE_USER_BITS         (_ASCE_SPACE_SWITCH | _ASCE_PRIVATE_SPACE | \
                                 _ASCE_ALT_EVENT)

/*
 * Page protection definitions.
 */
#define PAGE_NONE       __pgprot(_PAGE_PRESENT | _PAGE_INVALID | _PAGE_PROTECT)
#define PAGE_RO         __pgprot(_PAGE_PRESENT | _PAGE_READ | \
                                 _PAGE_NOEXEC  | _PAGE_INVALID | _PAGE_PROTECT)
#define PAGE_RX         __pgprot(_PAGE_PRESENT | _PAGE_READ | \
                                 _PAGE_INVALID | _PAGE_PROTECT)
#define PAGE_RW         __pgprot(_PAGE_PRESENT | _PAGE_READ | _PAGE_WRITE | \
                                 _PAGE_NOEXEC  | _PAGE_INVALID | _PAGE_PROTECT)
#define PAGE_RWX        __pgprot(_PAGE_PRESENT | _PAGE_READ | _PAGE_WRITE | \
                                 _PAGE_INVALID | _PAGE_PROTECT)

#define PAGE_SHARED     __pgprot(_PAGE_PRESENT | _PAGE_READ | _PAGE_WRITE | \
                                 _PAGE_YOUNG | _PAGE_DIRTY | _PAGE_NOEXEC)
#define PAGE_KERNEL     __pgprot(_PAGE_PRESENT | _PAGE_READ | _PAGE_WRITE | \
                                 _PAGE_YOUNG | _PAGE_DIRTY | _PAGE_NOEXEC)
#define PAGE_KERNEL_RO  __pgprot(_PAGE_PRESENT | _PAGE_READ | _PAGE_YOUNG | \
                                 _PAGE_PROTECT | _PAGE_NOEXEC)
#define PAGE_KERNEL_EXEC __pgprot(_PAGE_PRESENT | _PAGE_READ | _PAGE_WRITE | \
                                  _PAGE_YOUNG | _PAGE_DIRTY)

/*
 * On s390 the page table entry has an invalid bit and a read-only bit.
 * Read permission implies execute permission and write permission
 * implies read permission.
 */
         /*xwr*/
#define __P000  PAGE_NONE
#define __P001  PAGE_RO
#define __P010  PAGE_RO
#define __P011  PAGE_RO
#define __P100  PAGE_RX
#define __P101  PAGE_RX
#define __P110  PAGE_RX
#define __P111  PAGE_RX

#define __S000  PAGE_NONE
#define __S001  PAGE_RO
#define __S010  PAGE_RW
#define __S011  PAGE_RW
#define __S100  PAGE_RX
#define __S101  PAGE_RX
#define __S110  PAGE_RWX
#define __S111  PAGE_RWX

/*
 * Segment entry (large page) protection definitions.
 */
#define SEGMENT_NONE    __pgprot(_SEGMENT_ENTRY_INVALID | \
                                 _SEGMENT_ENTRY_PROTECT)
#define SEGMENT_RO      __pgprot(_SEGMENT_ENTRY_PROTECT | \
                                 _SEGMENT_ENTRY_READ | \
                                 _SEGMENT_ENTRY_NOEXEC)
#define SEGMENT_RX      __pgprot(_SEGMENT_ENTRY_PROTECT | \
                                 _SEGMENT_ENTRY_READ)
#define SEGMENT_RW      __pgprot(_SEGMENT_ENTRY_READ | \
                                 _SEGMENT_ENTRY_WRITE | \
                                 _SEGMENT_ENTRY_NOEXEC)
#define SEGMENT_RWX     __pgprot(_SEGMENT_ENTRY_READ | \
                                 _SEGMENT_ENTRY_WRITE)
#define SEGMENT_KERNEL  __pgprot(_SEGMENT_ENTRY |       \
                                 _SEGMENT_ENTRY_LARGE | \
                                 _SEGMENT_ENTRY_READ |  \
                                 _SEGMENT_ENTRY_WRITE | \
                                 _SEGMENT_ENTRY_YOUNG | \
                                 _SEGMENT_ENTRY_DIRTY | \
                                 _SEGMENT_ENTRY_NOEXEC)
#define SEGMENT_KERNEL_RO __pgprot(_SEGMENT_ENTRY |     \
                                 _SEGMENT_ENTRY_LARGE | \
                                 _SEGMENT_ENTRY_READ |  \
                                 _SEGMENT_ENTRY_YOUNG | \
                                 _SEGMENT_ENTRY_PROTECT | \
                                 _SEGMENT_ENTRY_NOEXEC)
#define SEGMENT_KERNEL_EXEC __pgprot(_SEGMENT_ENTRY |   \
                                 _SEGMENT_ENTRY_LARGE | \
                                 _SEGMENT_ENTRY_READ |  \
                                 _SEGMENT_ENTRY_WRITE | \
                                 _SEGMENT_ENTRY_YOUNG | \
                                 _SEGMENT_ENTRY_DIRTY)

/*
 * Region3 entry (large page) protection definitions.
 */

#define REGION3_KERNEL  __pgprot(_REGION_ENTRY_TYPE_R3 | \
                                 _REGION3_ENTRY_LARGE |  \
                                 _REGION3_ENTRY_READ |   \
                                 _REGION3_ENTRY_WRITE |  \
                                 _REGION3_ENTRY_YOUNG |  \
                                 _REGION3_ENTRY_DIRTY | \
                                 _REGION_ENTRY_NOEXEC)
#define REGION3_KERNEL_RO __pgprot(_REGION_ENTRY_TYPE_R3 | \
                                   _REGION3_ENTRY_LARGE |  \
                                   _REGION3_ENTRY_READ |   \
                                   _REGION3_ENTRY_YOUNG |  \
                                   _REGION_ENTRY_PROTECT | \
                                   _REGION_ENTRY_NOEXEC)

static inline bool mm_p4d_folded(struct mm_struct *mm)
{
        return mm->context.asce_limit <= _REGION1_SIZE;
}
#define mm_p4d_folded(mm) mm_p4d_folded(mm)

static inline bool mm_pud_folded(struct mm_struct *mm)
{
        return mm->context.asce_limit <= _REGION2_SIZE;
}
#define mm_pud_folded(mm) mm_pud_folded(mm)

static inline bool mm_pmd_folded(struct mm_struct *mm)
{
        return mm->context.asce_limit <= _REGION3_SIZE;
}
#define mm_pmd_folded(mm) mm_pmd_folded(mm)

static inline int mm_has_pgste(struct mm_struct *mm)
{
#ifdef CONFIG_PGSTE
        if (unlikely(mm->context.has_pgste))
                return 1;
#endif
        return 0;
}

static inline int mm_is_protected(struct mm_struct *mm)
{
#ifdef CONFIG_PGSTE
        if (unlikely(atomic_read(&mm->context.is_protected)))
                return 1;
#endif
        return 0;
}

static inline int mm_alloc_pgste(struct mm_struct *mm)
{
#ifdef CONFIG_PGSTE
        if (unlikely(mm->context.alloc_pgste))
                return 1;
#endif
        return 0;
}

/*
 * In the case that a guest uses storage keys
 * faults should no longer be backed by zero pages
 */
#define mm_forbids_zeropage mm_has_pgste
static inline int mm_uses_skeys(struct mm_struct *mm)
{
#ifdef CONFIG_PGSTE
        if (mm->context.uses_skeys)
                return 1;
#endif
        return 0;
}

static inline void csp(unsigned int *ptr, unsigned int old, unsigned int new)
{
        register unsigned long reg2 asm("2") = old;
        register unsigned long reg3 asm("3") = new;
        unsigned long address = (unsigned long)ptr | 1;

        asm volatile(
                "       csp     %0,%3"
                : "+d" (reg2), "+m" (*ptr)
                : "d" (reg3), "d" (address)
                : "cc");
}

static inline void cspg(unsigned long *ptr, unsigned long old, unsigned long new)
{
        register unsigned long reg2 asm("2") = old;
        register unsigned long reg3 asm("3") = new;
        unsigned long address = (unsigned long)ptr | 1;

        asm volatile(
                "       .insn   rre,0xb98a0000,%0,%3"
                : "+d" (reg2), "+m" (*ptr)
                : "d" (reg3), "d" (address)
                : "cc");
}

#define CRDTE_DTT_PAGE          0x00UL
#define CRDTE_DTT_SEGMENT       0x10UL
#define CRDTE_DTT_REGION3       0x14UL
#define CRDTE_DTT_REGION2       0x18UL
#define CRDTE_DTT_REGION1       0x1cUL

static inline void crdte(unsigned long old, unsigned long new,
                         unsigned long table, unsigned long dtt,
                         unsigned long address, unsigned long asce)
{
        register unsigned long reg2 asm("2") = old;
        register unsigned long reg3 asm("3") = new;
        register unsigned long reg4 asm("4") = table | dtt;
        register unsigned long reg5 asm("5") = address;

        asm volatile(".insn rrf,0xb98f0000,%0,%2,%4,0"
                     : "+d" (reg2)
                     : "d" (reg3), "d" (reg4), "d" (reg5), "a" (asce)
                     : "memory", "cc");
}

/*
 * pgd/p4d/pud/pmd/pte query functions
 */
static inline int pgd_folded(pgd_t pgd)
{
        return (pgd_val(pgd) & _REGION_ENTRY_TYPE_MASK) < _REGION_ENTRY_TYPE_R1;
}

static inline int pgd_present(pgd_t pgd)
{
        if (pgd_folded(pgd))
                return 1;
        return (pgd_val(pgd) & _REGION_ENTRY_ORIGIN) != 0UL;
}

static inline int pgd_none(pgd_t pgd)
{
        if (pgd_folded(pgd))
                return 0;
        return (pgd_val(pgd) & _REGION_ENTRY_INVALID) != 0UL;
}

static inline int pgd_bad(pgd_t pgd)
{
        if ((pgd_val(pgd) & _REGION_ENTRY_TYPE_MASK) < _REGION_ENTRY_TYPE_R1)
                return 0;
        return (pgd_val(pgd) & ~_REGION_ENTRY_BITS) != 0;
}

static inline unsigned long pgd_pfn(pgd_t pgd)
{
        unsigned long origin_mask;

        origin_mask = _REGION_ENTRY_ORIGIN;
        return (pgd_val(pgd) & origin_mask) >> PAGE_SHIFT;
}

static inline int p4d_folded(p4d_t p4d)
{
        return (p4d_val(p4d) & _REGION_ENTRY_TYPE_MASK) < _REGION_ENTRY_TYPE_R2;
}

static inline int p4d_present(p4d_t p4d)
{
        if (p4d_folded(p4d))
                return 1;
        return (p4d_val(p4d) & _REGION_ENTRY_ORIGIN) != 0UL;
}

static inline int p4d_none(p4d_t p4d)
{
        if (p4d_folded(p4d))
                return 0;
        return p4d_val(p4d) == _REGION2_ENTRY_EMPTY;
}

static inline unsigned long p4d_pfn(p4d_t p4d)
{
        unsigned long origin_mask;

        origin_mask = _REGION_ENTRY_ORIGIN;
        return (p4d_val(p4d) & origin_mask) >> PAGE_SHIFT;
}

static inline int pud_folded(pud_t pud)
{
        return (pud_val(pud) & _REGION_ENTRY_TYPE_MASK) < _REGION_ENTRY_TYPE_R3;
}

static inline int pud_present(pud_t pud)
{
        if (pud_folded(pud))
                return 1;
        return (pud_val(pud) & _REGION_ENTRY_ORIGIN) != 0UL;
}

static inline int pud_none(pud_t pud)
{
        if (pud_folded(pud))
                return 0;
        return pud_val(pud) == _REGION3_ENTRY_EMPTY;
}

#define pud_leaf        pud_large
static inline int pud_large(pud_t pud)
{
        if ((pud_val(pud) & _REGION_ENTRY_TYPE_MASK) != _REGION_ENTRY_TYPE_R3)
                return 0;
        return !!(pud_val(pud) & _REGION3_ENTRY_LARGE);
}

#define pmd_leaf        pmd_large
static inline int pmd_large(pmd_t pmd)
{
        return (pmd_val(pmd) & _SEGMENT_ENTRY_LARGE) != 0;
}

static inline int pmd_bad(pmd_t pmd)
{
        if ((pmd_val(pmd) & _SEGMENT_ENTRY_TYPE_MASK) > 0 || pmd_large(pmd))
                return 1;
        return (pmd_val(pmd) & ~_SEGMENT_ENTRY_BITS) != 0;
}

static inline int pud_bad(pud_t pud)
{
        unsigned long type = pud_val(pud) & _REGION_ENTRY_TYPE_MASK;

        if (type > _REGION_ENTRY_TYPE_R3 || pud_large(pud))
                return 1;
        if (type < _REGION_ENTRY_TYPE_R3)
                return 0;
        return (pud_val(pud) & ~_REGION_ENTRY_BITS) != 0;
}

static inline int p4d_bad(p4d_t p4d)
{
        unsigned long type = p4d_val(p4d) & _REGION_ENTRY_TYPE_MASK;

        if (type > _REGION_ENTRY_TYPE_R2)
                return 1;
        if (type < _REGION_ENTRY_TYPE_R2)
                return 0;
        return (p4d_val(p4d) & ~_REGION_ENTRY_BITS) != 0;
}

static inline int pmd_present(pmd_t pmd)
{
        return pmd_val(pmd) != _SEGMENT_ENTRY_EMPTY;
}

static inline int pmd_none(pmd_t pmd)
{
        return pmd_val(pmd) == _SEGMENT_ENTRY_EMPTY;
}

#define pmd_write pmd_write
static inline int pmd_write(pmd_t pmd)
{
        return (pmd_val(pmd) & _SEGMENT_ENTRY_WRITE) != 0;
}

#define pud_write pud_write
static inline int pud_write(pud_t pud)
{
        return (pud_val(pud) & _REGION3_ENTRY_WRITE) != 0;
}

static inline int pmd_dirty(pmd_t pmd)
{
        return (pmd_val(pmd) & _SEGMENT_ENTRY_DIRTY) != 0;
}

static inline int pmd_young(pmd_t pmd)
{
        return (pmd_val(pmd) & _SEGMENT_ENTRY_YOUNG) != 0;
}

static inline int pte_present(pte_t pte)
{
        /* Bit pattern: (pte & 0x001) == 0x001 */
        return (pte_val(pte) & _PAGE_PRESENT) != 0;
}

static inline int pte_none(pte_t pte)
{
        /* Bit pattern: pte == 0x400 */
        return pte_val(pte) == _PAGE_INVALID;
}

static inline int pte_swap(pte_t pte)
{
        /* Bit pattern: (pte & 0x201) == 0x200 */
        return (pte_val(pte) & (_PAGE_PROTECT | _PAGE_PRESENT))
                == _PAGE_PROTECT;
}

static inline int pte_special(pte_t pte)
{
        return (pte_val(pte) & _PAGE_SPECIAL);
}

#define __HAVE_ARCH_PTE_SAME
static inline int pte_same(pte_t a, pte_t b)
{
        return pte_val(a) == pte_val(b);
}

#ifdef CONFIG_NUMA_BALANCING
static inline int pte_protnone(pte_t pte)
{
        return pte_present(pte) && !(pte_val(pte) & _PAGE_READ);
}

static inline int pmd_protnone(pmd_t pmd)
{
        /* pmd_large(pmd) implies pmd_present(pmd) */
        return pmd_large(pmd) && !(pmd_val(pmd) & _SEGMENT_ENTRY_READ);
}
#endif

static inline int pte_soft_dirty(pte_t pte)
{
        return pte_val(pte) & _PAGE_SOFT_DIRTY;
}
#define pte_swp_soft_dirty pte_soft_dirty

static inline pte_t pte_mksoft_dirty(pte_t pte)
{
        pte_val(pte) |= _PAGE_SOFT_DIRTY;
        return pte;
}
#define pte_swp_mksoft_dirty pte_mksoft_dirty

static inline pte_t pte_clear_soft_dirty(pte_t pte)
{
        pte_val(pte) &= ~_PAGE_SOFT_DIRTY;
        return pte;
}
#define pte_swp_clear_soft_dirty pte_clear_soft_dirty

static inline int pmd_soft_dirty(pmd_t pmd)
{
        return pmd_val(pmd) & _SEGMENT_ENTRY_SOFT_DIRTY;
}

static inline pmd_t pmd_mksoft_dirty(pmd_t pmd)
{
        pmd_val(pmd) |= _SEGMENT_ENTRY_SOFT_DIRTY;
        return pmd;
}

static inline pmd_t pmd_clear_soft_dirty(pmd_t pmd)
{
        pmd_val(pmd) &= ~_SEGMENT_ENTRY_SOFT_DIRTY;
        return pmd;
}

/*
 * query functions pte_write/pte_dirty/pte_young only work if
 * pte_present() is true. Undefined behaviour if not..
 */
static inline int pte_write(pte_t pte)
{
        return (pte_val(pte) & _PAGE_WRITE) != 0;
}

static inline int pte_dirty(pte_t pte)
{
        return (pte_val(pte) & _PAGE_DIRTY) != 0;
}

static inline int pte_young(pte_t pte)
{
        return (pte_val(pte) & _PAGE_YOUNG) != 0;
}

#define __HAVE_ARCH_PTE_UNUSED
static inline int pte_unused(pte_t pte)
{
        return pte_val(pte) & _PAGE_UNUSED;
}

/*
 * pgd/pmd/pte modification functions
 */

static inline void pgd_clear(pgd_t *pgd)
{
        if ((pgd_val(*pgd) & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R1)
                pgd_val(*pgd) = _REGION1_ENTRY_EMPTY;
}

static inline void p4d_clear(p4d_t *p4d)
{
        if ((p4d_val(*p4d) & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R2)
                p4d_val(*p4d) = _REGION2_ENTRY_EMPTY;
}

static inline void pud_clear(pud_t *pud)
{
        if ((pud_val(*pud) & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R3)
                pud_val(*pud) = _REGION3_ENTRY_EMPTY;
}

static inline void pmd_clear(pmd_t *pmdp)
{
        pmd_val(*pmdp) = _SEGMENT_ENTRY_EMPTY;
}

static inline void pte_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
{
        pte_val(*ptep) = _PAGE_INVALID;
}

/*
 * The following pte modification functions only work if
 * pte_present() is true. Undefined behaviour if not..
 */
static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
{
        pte_val(pte) &= _PAGE_CHG_MASK;
        pte_val(pte) |= pgprot_val(newprot);
        /*
         * newprot for PAGE_NONE, PAGE_RO, PAGE_RX, PAGE_RW and PAGE_RWX
         * has the invalid bit set, clear it again for readable, young pages
         */
        if ((pte_val(pte) & _PAGE_YOUNG) && (pte_val(pte) & _PAGE_READ))
                pte_val(pte) &= ~_PAGE_INVALID;
        /*
         * newprot for PAGE_RO, PAGE_RX, PAGE_RW and PAGE_RWX has the page
         * protection bit set, clear it again for writable, dirty pages
         */
        if ((pte_val(pte) & _PAGE_DIRTY) && (pte_val(pte) & _PAGE_WRITE))
                pte_val(pte) &= ~_PAGE_PROTECT;
        return pte;
}

static inline pte_t pte_wrprotect(pte_t pte)
{
        pte_val(pte) &= ~_PAGE_WRITE;
        pte_val(pte) |= _PAGE_PROTECT;
        return pte;
}

static inline pte_t pte_mkwrite(pte_t pte)
{
        pte_val(pte) |= _PAGE_WRITE;
        if (pte_val(pte) & _PAGE_DIRTY)
                pte_val(pte) &= ~_PAGE_PROTECT;
        return pte;
}

static inline pte_t pte_mkclean(pte_t pte)
{
        pte_val(pte) &= ~_PAGE_DIRTY;
        pte_val(pte) |= _PAGE_PROTECT;
        return pte;
}

static inline pte_t pte_mkdirty(pte_t pte)
{
        pte_val(pte) |= _PAGE_DIRTY | _PAGE_SOFT_DIRTY;
        if (pte_val(pte) & _PAGE_WRITE)
                pte_val(pte) &= ~_PAGE_PROTECT;
        return pte;
}

static inline pte_t pte_mkold(pte_t pte)
{
        pte_val(pte) &= ~_PAGE_YOUNG;
        pte_val(pte) |= _PAGE_INVALID;
        return pte;
}

static inline pte_t pte_mkyoung(pte_t pte)
{
        pte_val(pte) |= _PAGE_YOUNG;
        if (pte_val(pte) & _PAGE_READ)
                pte_val(pte) &= ~_PAGE_INVALID;
        return pte;
}

static inline pte_t pte_mkspecial(pte_t pte)
{
        pte_val(pte) |= _PAGE_SPECIAL;
        return pte;
}

#ifdef CONFIG_HUGETLB_PAGE
static inline pte_t pte_mkhuge(pte_t pte)
{
        pte_val(pte) |= _PAGE_LARGE;
        return pte;
}
#endif

#define IPTE_GLOBAL     0
#define IPTE_LOCAL      1

#define IPTE_NODAT      0x400
#define IPTE_GUEST_ASCE 0x800

static __always_inline void __ptep_ipte(unsigned long address, pte_t *ptep,
                                        unsigned long opt, unsigned long asce,
                                        int local)
{
        unsigned long pto = (unsigned long) ptep;

        if (__builtin_constant_p(opt) && opt == 0) {
                /* Invalidation + TLB flush for the pte */
                asm volatile(
                        "       .insn   rrf,0xb2210000,%[r1],%[r2],0,%[m4]"
                        : "+m" (*ptep) : [r1] "a" (pto), [r2] "a" (address),
                          [m4] "i" (local));
                return;

        }

        /* Invalidate ptes with options + TLB flush of the ptes */
        opt = opt | (asce & _ASCE_ORIGIN);
        asm volatile(
                "       .insn   rrf,0xb2210000,%[r1],%[r2],%[r3],%[m4]"
                : [r2] "+a" (address), [r3] "+a" (opt)
                : [r1] "a" (pto), [m4] "i" (local) : "memory");
}

static __always_inline void __ptep_ipte_range(unsigned long address, int nr,
                                              pte_t *ptep, int local)
{
        unsigned long pto = (unsigned long) ptep;

        /* Invalidate a range of ptes + TLB flush of the ptes */
        do {
                asm volatile(
                        "       .insn rrf,0xb2210000,%[r1],%[r2],%[r3],%[m4]"
                        : [r2] "+a" (address), [r3] "+a" (nr)
                        : [r1] "a" (pto), [m4] "i" (local) : "memory");
        } while (nr != 255);
}

/*
 * This is hard to understand. ptep_get_and_clear and ptep_clear_flush
 * both clear the TLB for the unmapped pte. The reason is that
 * ptep_get_and_clear is used in common code (e.g. change_pte_range)
 * to modify an active pte. The sequence is
 *   1) ptep_get_and_clear
 *   2) set_pte_at
 *   3) flush_tlb_range
 * On s390 the tlb needs to get flushed with the modification of the pte
 * if the pte is active. The only way how this can be implemented is to
 * have ptep_get_and_clear do the tlb flush. In exchange flush_tlb_range
 * is a nop.
 */
pte_t ptep_xchg_direct(struct mm_struct *, unsigned long, pte_t *, pte_t);
pte_t ptep_xchg_lazy(struct mm_struct *, unsigned long, pte_t *, pte_t);

#define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
static inline int ptep_test_and_clear_young(struct vm_area_struct *vma,
                                            unsigned long addr, pte_t *ptep)
{
        pte_t pte = *ptep;

        pte = ptep_xchg_direct(vma->vm_mm, addr, ptep, pte_mkold(pte));
        return pte_young(pte);
}

#define __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH
static inline int ptep_clear_flush_young(struct vm_area_struct *vma,
                                         unsigned long address, pte_t *ptep)
{
        return ptep_test_and_clear_young(vma, address, ptep);
}

#define __HAVE_ARCH_PTEP_GET_AND_CLEAR
static inline pte_t ptep_get_and_clear(struct mm_struct *mm,
                                       unsigned long addr, pte_t *ptep)
{
        pte_t res;

        res = ptep_xchg_lazy(mm, addr, ptep, __pte(_PAGE_INVALID));
        if (mm_is_protected(mm) && pte_present(res))
                uv_convert_from_secure(pte_val(res) & PAGE_MASK);
        return res;
}

#define __HAVE_ARCH_PTEP_MODIFY_PROT_TRANSACTION
pte_t ptep_modify_prot_start(struct vm_area_struct *, unsigned long, pte_t *);
void ptep_modify_prot_commit(struct vm_area_struct *, unsigned long,
                             pte_t *, pte_t, pte_t);

#define __HAVE_ARCH_PTEP_CLEAR_FLUSH
static inline pte_t ptep_clear_flush(struct vm_area_struct *vma,
                                     unsigned long addr, pte_t *ptep)
{
        pte_t res;

        res = ptep_xchg_direct(vma->vm_mm, addr, ptep, __pte(_PAGE_INVALID));
        if (mm_is_protected(vma->vm_mm) && pte_present(res))
                uv_convert_from_secure(pte_val(res) & PAGE_MASK);
        return res;
}

/*
 * The batched pte unmap code uses ptep_get_and_clear_full to clear the
 * ptes. Here an optimization is possible. tlb_gather_mmu flushes all
 * tlbs of an mm if it can guarantee that the ptes of the mm_struct
 * cannot be accessed while the batched unmap is running. In this case
 * full==1 and a simple pte_clear is enough. See tlb.h.
 */
#define __HAVE_ARCH_PTEP_GET_AND_CLEAR_FULL
static inline pte_t ptep_get_and_clear_full(struct mm_struct *mm,
                                            unsigned long addr,
                                            pte_t *ptep, int full)
{
        pte_t res;

        if (full) {
                res = *ptep;
                *ptep = __pte(_PAGE_INVALID);
        } else {
                res = ptep_xchg_lazy(mm, addr, ptep, __pte(_PAGE_INVALID));
        }
        if (mm_is_protected(mm) && pte_present(res))
                uv_convert_from_secure(pte_val(res) & PAGE_MASK);
        return res;
}

#define __HAVE_ARCH_PTEP_SET_WRPROTECT
static inline void ptep_set_wrprotect(struct mm_struct *mm,
                                      unsigned long addr, pte_t *ptep)
{
        pte_t pte = *ptep;

        if (pte_write(pte))
                ptep_xchg_lazy(mm, addr, ptep, pte_wrprotect(pte));
}

#define __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
static inline int ptep_set_access_flags(struct vm_area_struct *vma,
                                        unsigned long addr, pte_t *ptep,
                                        pte_t entry, int dirty)
{
        if (pte_same(*ptep, entry))
                return 0;
        ptep_xchg_direct(vma->vm_mm, addr, ptep, entry);
        return 1;
}

/*
 * Additional functions to handle KVM guest page tables
 */
void ptep_set_pte_at(struct mm_struct *mm, unsigned long addr,
                     pte_t *ptep, pte_t entry);
void ptep_set_notify(struct mm_struct *mm, unsigned long addr, pte_t *ptep);
void ptep_notify(struct mm_struct *mm, unsigned long addr,
                 pte_t *ptep, unsigned long bits);
int ptep_force_prot(struct mm_struct *mm, unsigned long gaddr,
                    pte_t *ptep, int prot, unsigned long bit);
void ptep_zap_unused(struct mm_struct *mm, unsigned long addr,
                     pte_t *ptep , int reset);
void ptep_zap_key(struct mm_struct *mm, unsigned long addr, pte_t *ptep);
int ptep_shadow_pte(struct mm_struct *mm, unsigned long saddr,
                    pte_t *sptep, pte_t *tptep, pte_t pte);
void ptep_unshadow_pte(struct mm_struct *mm, unsigned long saddr, pte_t *ptep);

bool ptep_test_and_clear_uc(struct mm_struct *mm, unsigned long address,
                            pte_t *ptep);
int set_guest_storage_key(struct mm_struct *mm, unsigned long addr,
                          unsigned char key, bool nq);
int cond_set_guest_storage_key(struct mm_struct *mm, unsigned long addr,
                               unsigned char key, unsigned char *oldkey,
                               bool nq, bool mr, bool mc);
int reset_guest_reference_bit(struct mm_struct *mm, unsigned long addr);
int get_guest_storage_key(struct mm_struct *mm, unsigned long addr,
                          unsigned char *key);

int set_pgste_bits(struct mm_struct *mm, unsigned long addr,
                                unsigned long bits, unsigned long value);
int get_pgste(struct mm_struct *mm, unsigned long hva, unsigned long *pgstep);
int pgste_perform_essa(struct mm_struct *mm, unsigned long hva, int orc,
                        unsigned long *oldpte, unsigned long *oldpgste);
void gmap_pmdp_csp(struct mm_struct *mm, unsigned long vmaddr);
void gmap_pmdp_invalidate(struct mm_struct *mm, unsigned long vmaddr);
void gmap_pmdp_idte_local(struct mm_struct *mm, unsigned long vmaddr);
void gmap_pmdp_idte_global(struct mm_struct *mm, unsigned long vmaddr);

#define pgprot_writecombine     pgprot_writecombine
pgprot_t pgprot_writecombine(pgprot_t prot);

#define pgprot_writethrough     pgprot_writethrough
pgprot_t pgprot_writethrough(pgprot_t prot);

/*
 * Certain architectures need to do special things when PTEs
 * within a page table are directly modified.  Thus, the following
 * hook is made available.
 */
static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
                              pte_t *ptep, pte_t entry)
{
        if (pte_present(entry))
                pte_val(entry) &= ~_PAGE_UNUSED;
        if (mm_has_pgste(mm))
                ptep_set_pte_at(mm, addr, ptep, entry);
        else
                *ptep = entry;
}

/*
 * Conversion functions: convert a page and protection to a page entry,
 * and a page entry and page directory to the page they refer to.
 */
static inline pte_t mk_pte_phys(unsigned long physpage, pgprot_t pgprot)
{
        pte_t __pte;

        pte_val(__pte) = physpage | pgprot_val(pgprot);
        if (!MACHINE_HAS_NX)
                pte_val(__pte) &= ~_PAGE_NOEXEC;
        return pte_mkyoung(__pte);
}

static inline pte_t mk_pte(struct page *page, pgprot_t pgprot)
{
        unsigned long physpage = page_to_phys(page);
        pte_t __pte = mk_pte_phys(physpage, pgprot);

        if (pte_write(__pte) && PageDirty(page))
                __pte = pte_mkdirty(__pte);
        return __pte;
}

#define pgd_index(address) (((address) >> PGDIR_SHIFT) & (PTRS_PER_PGD-1))
#define p4d_index(address) (((address) >> P4D_SHIFT) & (PTRS_PER_P4D-1))
#define pud_index(address) (((address) >> PUD_SHIFT) & (PTRS_PER_PUD-1))
#define pmd_index(address) (((address) >> PMD_SHIFT) & (PTRS_PER_PMD-1))

#define p4d_deref(pud) ((unsigned long)__va(p4d_val(pud) & _REGION_ENTRY_ORIGIN))
#define pgd_deref(pgd) ((unsigned long)__va(pgd_val(pgd) & _REGION_ENTRY_ORIGIN))

static inline unsigned long pmd_deref(pmd_t pmd)
{
        unsigned long origin_mask;

        origin_mask = _SEGMENT_ENTRY_ORIGIN;
        if (pmd_large(pmd))
                origin_mask = _SEGMENT_ENTRY_ORIGIN_LARGE;
        return (unsigned long)__va(pmd_val(pmd) & origin_mask);
}

static inline unsigned long pmd_pfn(pmd_t pmd)
{
        return __pa(pmd_deref(pmd)) >> PAGE_SHIFT;
}

static inline unsigned long pud_deref(pud_t pud)
{
        unsigned long origin_mask;

        origin_mask = _REGION_ENTRY_ORIGIN;
        if (pud_large(pud))
                origin_mask = _REGION3_ENTRY_ORIGIN_LARGE;
        return (unsigned long)__va(pud_val(pud) & origin_mask);
}

static inline unsigned long pud_pfn(pud_t pud)
{
        return __pa(pud_deref(pud)) >> PAGE_SHIFT;
}

/*
 * The pgd_offset function *always* adds the index for the top-level
 * region/segment table. This is done to get a sequence like the
 * following to work:
 *      pgdp = pgd_offset(current->mm, addr);
 *      pgd = READ_ONCE(*pgdp);
 *      p4dp = p4d_offset(&pgd, addr);
 *      ...
 * The subsequent p4d_offset, pud_offset and pmd_offset functions
 * only add an index if they dereferenced the pointer.
 */
static inline pgd_t *pgd_offset_raw(pgd_t *pgd, unsigned long address)
{
        unsigned long rste;
        unsigned int shift;

        /* Get the first entry of the top level table */
        rste = pgd_val(*pgd);
        /* Pick up the shift from the table type of the first entry */
        shift = ((rste & _REGION_ENTRY_TYPE_MASK) >> 2) * 11 + 20;
        return pgd + ((address >> shift) & (PTRS_PER_PGD - 1));
}

#define pgd_offset(mm, address) pgd_offset_raw(READ_ONCE((mm)->pgd), address)

static inline p4d_t *p4d_offset_lockless(pgd_t *pgdp, pgd_t pgd, unsigned long address)
{
        if ((pgd_val(pgd) & _REGION_ENTRY_TYPE_MASK) >= _REGION_ENTRY_TYPE_R1)
                return (p4d_t *) pgd_deref(pgd) + p4d_index(address);
        return (p4d_t *) pgdp;
}
#define p4d_offset_lockless p4d_offset_lockless

static inline p4d_t *p4d_offset(pgd_t *pgdp, unsigned long address)
{
        return p4d_offset_lockless(pgdp, *pgdp, address);
}

static inline pud_t *pud_offset_lockless(p4d_t *p4dp, p4d_t p4d, unsigned long address)
{
        if ((p4d_val(p4d) & _REGION_ENTRY_TYPE_MASK) >= _REGION_ENTRY_TYPE_R2)
                return (pud_t *) p4d_deref(p4d) + pud_index(address);
        return (pud_t *) p4dp;
}
#define pud_offset_lockless pud_offset_lockless

static inline pud_t *pud_offset(p4d_t *p4dp, unsigned long address)
{
        return pud_offset_lockless(p4dp, *p4dp, address);
}
#define pud_offset pud_offset

static inline pmd_t *pmd_offset_lockless(pud_t *pudp, pud_t pud, unsigned long address)
{
        if ((pud_val(pud) & _REGION_ENTRY_TYPE_MASK) >= _REGION_ENTRY_TYPE_R3)
                return (pmd_t *) pud_deref(pud) + pmd_index(address);
        return (pmd_t *) pudp;
}
#define pmd_offset_lockless pmd_offset_lockless

static inline pmd_t *pmd_offset(pud_t *pudp, unsigned long address)
{
        return pmd_offset_lockless(pudp, *pudp, address);
}
#define pmd_offset pmd_offset

static inline unsigned long pmd_page_vaddr(pmd_t pmd)
{
        return (unsigned long) pmd_deref(pmd);
}

static inline bool gup_fast_permitted(unsigned long start, unsigned long end)
{
        return end <= current->mm->context.asce_limit;
}
#define gup_fast_permitted gup_fast_permitted

#define pfn_pte(pfn, pgprot)    mk_pte_phys(((pfn) << PAGE_SHIFT), (pgprot))
#define pte_pfn(x) (pte_val(x) >> PAGE_SHIFT)
#define pte_page(x) pfn_to_page(pte_pfn(x))

#define pmd_page(pmd) pfn_to_page(pmd_pfn(pmd))
#define pud_page(pud) pfn_to_page(pud_pfn(pud))
#define p4d_page(p4d) pfn_to_page(p4d_pfn(p4d))
#define pgd_page(pgd) pfn_to_page(pgd_pfn(pgd))

static inline pmd_t pmd_wrprotect(pmd_t pmd)
{
        pmd_val(pmd) &= ~_SEGMENT_ENTRY_WRITE;
        pmd_val(pmd) |= _SEGMENT_ENTRY_PROTECT;
        return pmd;
}

static inline pmd_t pmd_mkwrite(pmd_t pmd)
{
        pmd_val(pmd) |= _SEGMENT_ENTRY_WRITE;
        if (pmd_val(pmd) & _SEGMENT_ENTRY_DIRTY)
                pmd_val(pmd) &= ~_SEGMENT_ENTRY_PROTECT;
        return pmd;
}

static inline pmd_t pmd_mkclean(pmd_t pmd)
{
        pmd_val(pmd) &= ~_SEGMENT_ENTRY_DIRTY;
        pmd_val(pmd) |= _SEGMENT_ENTRY_PROTECT;
        return pmd;
}

static inline pmd_t pmd_mkdirty(pmd_t pmd)
{
        pmd_val(pmd) |= _SEGMENT_ENTRY_DIRTY | _SEGMENT_ENTRY_SOFT_DIRTY;
        if (pmd_val(pmd) & _SEGMENT_ENTRY_WRITE)
                pmd_val(pmd) &= ~_SEGMENT_ENTRY_PROTECT;
        return pmd;
}

static inline pud_t pud_wrprotect(pud_t pud)
{
        pud_val(pud) &= ~_REGION3_ENTRY_WRITE;
        pud_val(pud) |= _REGION_ENTRY_PROTECT;
        return pud;
}

static inline pud_t pud_mkwrite(pud_t pud)
{
        pud_val(pud) |= _REGION3_ENTRY_WRITE;
        if (pud_val(pud) & _REGION3_ENTRY_DIRTY)
                pud_val(pud) &= ~_REGION_ENTRY_PROTECT;
        return pud;
}

static inline pud_t pud_mkclean(pud_t pud)
{
        pud_val(pud) &= ~_REGION3_ENTRY_DIRTY;
        pud_val(pud) |= _REGION_ENTRY_PROTECT;
        return pud;
}

static inline pud_t pud_mkdirty(pud_t pud)
{
        pud_val(pud) |= _REGION3_ENTRY_DIRTY | _REGION3_ENTRY_SOFT_DIRTY;
        if (pud_val(pud) & _REGION3_ENTRY_WRITE)
                pud_val(pud) &= ~_REGION_ENTRY_PROTECT;
        return pud;
}

#if defined(CONFIG_TRANSPARENT_HUGEPAGE) || defined(CONFIG_HUGETLB_PAGE)
static inline unsigned long massage_pgprot_pmd(pgprot_t pgprot)
{
        /*
         * pgprot is PAGE_NONE, PAGE_RO, PAGE_RX, PAGE_RW or PAGE_RWX
         * (see __Pxxx / __Sxxx). Convert to segment table entry format.
         */
        if (pgprot_val(pgprot) == pgprot_val(PAGE_NONE))
                return pgprot_val(SEGMENT_NONE);
        if (pgprot_val(pgprot) == pgprot_val(PAGE_RO))
                return pgprot_val(SEGMENT_RO);
        if (pgprot_val(pgprot) == pgprot_val(PAGE_RX))
                return pgprot_val(SEGMENT_RX);
        if (pgprot_val(pgprot) == pgprot_val(PAGE_RW))
                return pgprot_val(SEGMENT_RW);
        return pgprot_val(SEGMENT_RWX);
}

static inline pmd_t pmd_mkyoung(pmd_t pmd)
{
        pmd_val(pmd) |= _SEGMENT_ENTRY_YOUNG;
        if (pmd_val(pmd) & _SEGMENT_ENTRY_READ)
                pmd_val(pmd) &= ~_SEGMENT_ENTRY_INVALID;
        return pmd;
}

static inline pmd_t pmd_mkold(pmd_t pmd)
{
        pmd_val(pmd) &= ~_SEGMENT_ENTRY_YOUNG;
        pmd_val(pmd) |= _SEGMENT_ENTRY_INVALID;
        return pmd;
}

static inline pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot)
{
        pmd_val(pmd) &= _SEGMENT_ENTRY_ORIGIN_LARGE |
                _SEGMENT_ENTRY_DIRTY | _SEGMENT_ENTRY_YOUNG |
                _SEGMENT_ENTRY_LARGE | _SEGMENT_ENTRY_SOFT_DIRTY;
        pmd_val(pmd) |= massage_pgprot_pmd(newprot);
        if (!(pmd_val(pmd) & _SEGMENT_ENTRY_DIRTY))
                pmd_val(pmd) |= _SEGMENT_ENTRY_PROTECT;
        if (!(pmd_val(pmd) & _SEGMENT_ENTRY_YOUNG))
                pmd_val(pmd) |= _SEGMENT_ENTRY_INVALID;
        return pmd;
}

static inline pmd_t mk_pmd_phys(unsigned long physpage, pgprot_t pgprot)
{
        pmd_t __pmd;
        pmd_val(__pmd) = physpage + massage_pgprot_pmd(pgprot);
        return __pmd;
}

#endif /* CONFIG_TRANSPARENT_HUGEPAGE || CONFIG_HUGETLB_PAGE */

static inline void __pmdp_csp(pmd_t *pmdp)
{
        csp((unsigned int *)pmdp + 1, pmd_val(*pmdp),
            pmd_val(*pmdp) | _SEGMENT_ENTRY_INVALID);
}

#define IDTE_GLOBAL     0
#define IDTE_LOCAL      1

#define IDTE_PTOA       0x0800
#define IDTE_NODAT      0x1000
#define IDTE_GUEST_ASCE 0x2000

static __always_inline void __pmdp_idte(unsigned long addr, pmd_t *pmdp,
                                        unsigned long opt, unsigned long asce,
                                        int local)
{
        unsigned long sto;

        sto = (unsigned long) pmdp - pmd_index(addr) * sizeof(pmd_t);
        if (__builtin_constant_p(opt) && opt == 0) {
                /* flush without guest asce */
                asm volatile(
                        "       .insn   rrf,0xb98e0000,%[r1],%[r2],0,%[m4]"
                        : "+m" (*pmdp)
                        : [r1] "a" (sto), [r2] "a" ((addr & HPAGE_MASK)),
                          [m4] "i" (local)
                        : "cc" );
        } else {
                /* flush with guest asce */
                asm volatile(
                        "       .insn   rrf,0xb98e0000,%[r1],%[r2],%[r3],%[m4]"
                        : "+m" (*pmdp)
                        : [r1] "a" (sto), [r2] "a" ((addr & HPAGE_MASK) | opt),
                          [r3] "a" (asce), [m4] "i" (local)
                        : "cc" );
        }
}

static __always_inline void __pudp_idte(unsigned long addr, pud_t *pudp,
                                        unsigned long opt, unsigned long asce,
                                        int local)
{
        unsigned long r3o;

        r3o = (unsigned long) pudp - pud_index(addr) * sizeof(pud_t);
        r3o |= _ASCE_TYPE_REGION3;
        if (__builtin_constant_p(opt) && opt == 0) {
                /* flush without guest asce */
                asm volatile(
                        "       .insn   rrf,0xb98e0000,%[r1],%[r2],0,%[m4]"
                        : "+m" (*pudp)
                        : [r1] "a" (r3o), [r2] "a" ((addr & PUD_MASK)),
                          [m4] "i" (local)
                        : "cc");
        } else {
                /* flush with guest asce */
                asm volatile(
                        "       .insn   rrf,0xb98e0000,%[r1],%[r2],%[r3],%[m4]"
                        : "+m" (*pudp)
                        : [r1] "a" (r3o), [r2] "a" ((addr & PUD_MASK) | opt),
                          [r3] "a" (asce), [m4] "i" (local)
                        : "cc" );
        }
}

pmd_t pmdp_xchg_direct(struct mm_struct *, unsigned long, pmd_t *, pmd_t);
pmd_t pmdp_xchg_lazy(struct mm_struct *, unsigned long, pmd_t *, pmd_t);
pud_t pudp_xchg_direct(struct mm_struct *, unsigned long, pud_t *, pud_t);

#ifdef CONFIG_TRANSPARENT_HUGEPAGE

#define __HAVE_ARCH_PGTABLE_DEPOSIT
void pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp,
                                pgtable_t pgtable);

#define __HAVE_ARCH_PGTABLE_WITHDRAW
pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp);

#define  __HAVE_ARCH_PMDP_SET_ACCESS_FLAGS
static inline int pmdp_set_access_flags(struct vm_area_struct *vma,
                                        unsigned long addr, pmd_t *pmdp,
                                        pmd_t entry, int dirty)
{
        VM_BUG_ON(addr & ~HPAGE_MASK);

        entry = pmd_mkyoung(entry);
        if (dirty)
                entry = pmd_mkdirty(entry);
        if (pmd_val(*pmdp) == pmd_val(entry))
                return 0;
        pmdp_xchg_direct(vma->vm_mm, addr, pmdp, entry);
        return 1;
}

#define __HAVE_ARCH_PMDP_TEST_AND_CLEAR_YOUNG
static inline int pmdp_test_and_clear_young(struct vm_area_struct *vma,
                                            unsigned long addr, pmd_t *pmdp)
{
        pmd_t pmd = *pmdp;

        pmd = pmdp_xchg_direct(vma->vm_mm, addr, pmdp, pmd_mkold(pmd));
        return pmd_young(pmd);
}

#define __HAVE_ARCH_PMDP_CLEAR_YOUNG_FLUSH
static inline int pmdp_clear_flush_young(struct vm_area_struct *vma,
                                         unsigned long addr, pmd_t *pmdp)
{
        VM_BUG_ON(addr & ~HPAGE_MASK);
        return pmdp_test_and_clear_young(vma, addr, pmdp);
}

static inline void set_pmd_at(struct mm_struct *mm, unsigned long addr,
                              pmd_t *pmdp, pmd_t entry)
{
        if (!MACHINE_HAS_NX)
                pmd_val(entry) &= ~_SEGMENT_ENTRY_NOEXEC;
        *pmdp = entry;
}

static inline pmd_t pmd_mkhuge(pmd_t pmd)
{
        pmd_val(pmd) |= _SEGMENT_ENTRY_LARGE;
        pmd_val(pmd) |= _SEGMENT_ENTRY_YOUNG;
        pmd_val(pmd) |= _SEGMENT_ENTRY_PROTECT;
        return pmd;
}

#define __HAVE_ARCH_PMDP_HUGE_GET_AND_CLEAR
static inline pmd_t pmdp_huge_get_and_clear(struct mm_struct *mm,
                                            unsigned long addr, pmd_t *pmdp)
{
        return pmdp_xchg_direct(mm, addr, pmdp, __pmd(_SEGMENT_ENTRY_EMPTY));
}

#define __HAVE_ARCH_PMDP_HUGE_GET_AND_CLEAR_FULL
static inline pmd_t pmdp_huge_get_and_clear_full(struct vm_area_struct *vma,
                                                 unsigned long addr,
                                                 pmd_t *pmdp, int full)
{
        if (full) {
                pmd_t pmd = *pmdp;
                *pmdp = __pmd(_SEGMENT_ENTRY_EMPTY);
                return pmd;
        }
        return pmdp_xchg_lazy(vma->vm_mm, addr, pmdp, __pmd(_SEGMENT_ENTRY_EMPTY));
}

#define __HAVE_ARCH_PMDP_HUGE_CLEAR_FLUSH
static inline pmd_t pmdp_huge_clear_flush(struct vm_area_struct *vma,
                                          unsigned long addr, pmd_t *pmdp)
{
        return pmdp_huge_get_and_clear(vma->vm_mm, addr, pmdp);
}

#define __HAVE_ARCH_PMDP_INVALIDATE
static inline pmd_t pmdp_invalidate(struct vm_area_struct *vma,
                                   unsigned long addr, pmd_t *pmdp)
{
        pmd_t pmd = __pmd(pmd_val(*pmdp) | _SEGMENT_ENTRY_INVALID);

        return pmdp_xchg_direct(vma->vm_mm, addr, pmdp, pmd);
}

#define __HAVE_ARCH_PMDP_SET_WRPROTECT
static inline void pmdp_set_wrprotect(struct mm_struct *mm,
                                      unsigned long addr, pmd_t *pmdp)
{
        pmd_t pmd = *pmdp;

        if (pmd_write(pmd))
                pmd = pmdp_xchg_lazy(mm, addr, pmdp, pmd_wrprotect(pmd));
}

static inline pmd_t pmdp_collapse_flush(struct vm_area_struct *vma,
                                        unsigned long address,
                                        pmd_t *pmdp)
{
        return pmdp_huge_get_and_clear(vma->vm_mm, address, pmdp);
}
#define pmdp_collapse_flush pmdp_collapse_flush

#define pfn_pmd(pfn, pgprot)    mk_pmd_phys(((pfn) << PAGE_SHIFT), (pgprot))
#define mk_pmd(page, pgprot)    pfn_pmd(page_to_pfn(page), (pgprot))

static inline int pmd_trans_huge(pmd_t pmd)
{
        return pmd_val(pmd) & _SEGMENT_ENTRY_LARGE;
}

#define has_transparent_hugepage has_transparent_hugepage
static inline int has_transparent_hugepage(void)
{
        return MACHINE_HAS_EDAT1 ? 1 : 0;
}
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */

/*
 * 64 bit swap entry format:
 * A page-table entry has some bits we have to treat in a special way.
 * Bits 52 and bit 55 have to be zero, otherwise a specification
 * exception will occur instead of a page translation exception. The
 * specification exception has the bad habit not to store necessary
 * information in the lowcore.
 * Bits 54 and 63 are used to indicate the page type.
 * A swap pte is indicated by bit pattern (pte & 0x201) == 0x200
 * This leaves the bits 0-51 and bits 56-62 to store type and offset.
 * We use the 5 bits from 57-61 for the type and the 52 bits from 0-51
 * for the offset.
 * |                      offset                        |01100|type |00|
 * |0000000000111111111122222222223333333333444444444455|55555|55566|66|
 * |0123456789012345678901234567890123456789012345678901|23456|78901|23|
 */

#define __SWP_OFFSET_MASK       ((1UL << 52) - 1)
#define __SWP_OFFSET_SHIFT      12
#define __SWP_TYPE_MASK         ((1UL << 5) - 1)
#define __SWP_TYPE_SHIFT        2

static inline pte_t mk_swap_pte(unsigned long type, unsigned long offset)
{
        pte_t pte;

        pte_val(pte) = _PAGE_INVALID | _PAGE_PROTECT;
        pte_val(pte) |= (offset & __SWP_OFFSET_MASK) << __SWP_OFFSET_SHIFT;
        pte_val(pte) |= (type & __SWP_TYPE_MASK) << __SWP_TYPE_SHIFT;
        return pte;
}

static inline unsigned long __swp_type(swp_entry_t entry)
{
        return (entry.val >> __SWP_TYPE_SHIFT) & __SWP_TYPE_MASK;
}

static inline unsigned long __swp_offset(swp_entry_t entry)
{
        return (entry.val >> __SWP_OFFSET_SHIFT) & __SWP_OFFSET_MASK;
}

static inline swp_entry_t __swp_entry(unsigned long type, unsigned long offset)
{
        return (swp_entry_t) { pte_val(mk_swap_pte(type, offset)) };
}

#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)

extern int vmem_add_mapping(unsigned long start, unsigned long size);
extern void vmem_remove_mapping(unsigned long start, unsigned long size);
extern int s390_enable_sie(void);
extern int s390_enable_skey(void);
extern void s390_reset_cmma(struct mm_struct *mm);

/* s390 has a private copy of get unmapped area to deal with cache synonyms */
#define HAVE_ARCH_UNMAPPED_AREA
#define HAVE_ARCH_UNMAPPED_AREA_TOPDOWN

#endif /* _S390_PAGE_H */