/* SPDX-License-Identifier: GPL-2.0 */
/*
 *  S390 version
 *    Copyright IBM Corp. 1999, 2000
 *    Author(s): Hartmut Penner (hp@de.ibm.com)
 */

#ifndef _S390_PAGE_H
#define _S390_PAGE_H

#include <linux/const.h>
#include <asm/types.h>
#include <asm/asm.h>

#include <vdso/page.h>

#define PAGE_DEFAULT_ACC        _AC(0, UL)
/* storage-protection override */
#define PAGE_SPO_ACC            9
#define PAGE_DEFAULT_KEY        (PAGE_DEFAULT_ACC << 4)

#define HPAGE_SHIFT     20
#define HPAGE_SIZE      (1UL << HPAGE_SHIFT)
#define HPAGE_MASK      (~(HPAGE_SIZE - 1))
#define HUGETLB_PAGE_ORDER      (HPAGE_SHIFT - PAGE_SHIFT)
#define HUGE_MAX_HSTATE         2

#define ARCH_HAS_SETCLEAR_HUGE_PTE
#define ARCH_HAS_HUGE_PTE_TYPE
#define ARCH_HAS_PREPARE_HUGEPAGE
#define ARCH_HAS_HUGEPAGE_CLEAR_FLUSH

#define HAVE_ARCH_HUGETLB_UNMAPPED_AREA

#include <asm/setup.h>
#ifndef __ASSEMBLER__

void __storage_key_init_range(unsigned long start, unsigned long end);

static inline void storage_key_init_range(unsigned long start, unsigned long end)
{
        if (PAGE_DEFAULT_KEY != 0)
                __storage_key_init_range(start, end);
}

#define clear_page(page)        memset((page), 0, PAGE_SIZE)

/*
 * copy_page uses the mvcl instruction with 0xb0 padding byte in order to
 * bypass caches when copying a page. Especially when copying huge pages
 * this keeps L1 and L2 data caches alive.
 */
static inline void copy_page(void *to, void *from)
{
        union register_pair dst, src;

        dst.even = (unsigned long) to;
        dst.odd  = 0x1000;
        src.even = (unsigned long) from;
        src.odd  = 0xb0001000;

        asm volatile(
                "       mvcl    %[dst],%[src]"
                : [dst] "+&d" (dst.pair), [src] "+&d" (src.pair)
                : : "memory", "cc");
}

#define copy_user_page(to, from, vaddr, pg)     copy_page(to, from)

#define vma_alloc_zeroed_movable_folio(vma, vaddr) \
        vma_alloc_folio(GFP_HIGHUSER_MOVABLE | __GFP_ZERO, 0, vma, vaddr)

#ifdef CONFIG_STRICT_MM_TYPECHECKS
#define STRICT_MM_TYPECHECKS
#endif

#ifdef STRICT_MM_TYPECHECKS

typedef struct { unsigned long pgprot; } pgprot_t;
typedef struct { unsigned long pte; } pte_t;
typedef struct { unsigned long pmd; } pmd_t;
typedef struct { unsigned long pud; } pud_t;
typedef struct { unsigned long p4d; } p4d_t;
typedef struct { unsigned long pgd; } pgd_t;

#define DEFINE_PGVAL_FUNC(name)                                         \
static __always_inline unsigned long name ## _val(name ## _t name)      \
{                                                                       \
        return name.name;                                               \
}

#else /* STRICT_MM_TYPECHECKS */

typedef unsigned long pgprot_t;
typedef unsigned long pte_t;
typedef unsigned long pmd_t;
typedef unsigned long pud_t;
typedef unsigned long p4d_t;
typedef unsigned long pgd_t;

#define DEFINE_PGVAL_FUNC(name)                                         \
static __always_inline unsigned long name ## _val(name ## _t name)      \
{                                                                       \
        return name;                                                    \
}

#endif /* STRICT_MM_TYPECHECKS */

DEFINE_PGVAL_FUNC(pgprot)
DEFINE_PGVAL_FUNC(pte)
DEFINE_PGVAL_FUNC(pmd)
DEFINE_PGVAL_FUNC(pud)
DEFINE_PGVAL_FUNC(p4d)
DEFINE_PGVAL_FUNC(pgd)

typedef pte_t *pgtable_t;

#define __pgprot(x)     ((pgprot_t) { (x) } )
#define __pte(x)        ((pte_t) { (x) } )
#define __pmd(x)        ((pmd_t) { (x) } )
#define __pud(x)        ((pud_t) { (x) } )
#define __p4d(x)        ((p4d_t) { (x) } )
#define __pgd(x)        ((pgd_t) { (x) } )

static inline void page_set_storage_key(unsigned long addr,
                                        unsigned char skey, int mapped)
{
        if (!mapped) {
                asm volatile(
                        "       .insn   rrf,0xb22b0000,%[skey],%[addr],8,0"
                        :
                        : [skey] "d" (skey), [addr] "a" (addr)
                        : "memory");
        } else {
                asm volatile(
                        "       sske     %[skey],%[addr]"
                        :
                        : [skey] "d" (skey), [addr] "a" (addr)
                        : "memory");
        }
}

static inline unsigned char page_get_storage_key(unsigned long addr)
{
        unsigned char skey;

        asm volatile("iske %0,%1" : "=d" (skey) : "a" (addr));
        return skey;
}

static inline int page_reset_referenced(unsigned long addr)
{
        int cc;

        asm volatile(
                "       rrbe    0,%[addr]\n"
                CC_IPM(cc)
                : CC_OUT(cc, cc)
                : [addr] "a" (addr)
                : CC_CLOBBER);
        return CC_TRANSFORM(cc);
}

int split_pud_page(pud_t *pudp, unsigned long addr);

/* Bits int the storage key */
#define _PAGE_CHANGED           0x02    /* HW changed bit               */
#define _PAGE_REFERENCED        0x04    /* HW referenced bit            */
#define _PAGE_FP_BIT            0x08    /* HW fetch protection bit      */
#define _PAGE_ACC_BITS          0xf0    /* HW access control bits       */

struct page;
struct folio;
void arch_free_page(struct page *page, int order);
void arch_alloc_page(struct page *page, int order);

static inline int devmem_is_allowed(unsigned long pfn)
{
        return 0;
}

#define HAVE_ARCH_FREE_PAGE
#define HAVE_ARCH_ALLOC_PAGE

int arch_make_folio_accessible(struct folio *folio);
#define HAVE_ARCH_MAKE_FOLIO_ACCESSIBLE

struct vm_layout {
        unsigned long kaslr_offset;
        unsigned long kaslr_offset_phys;
        unsigned long identity_base;
        unsigned long identity_size;
};

extern struct vm_layout vm_layout;

#define __kaslr_offset          vm_layout.kaslr_offset
#define __kaslr_offset_phys     vm_layout.kaslr_offset_phys
#ifdef CONFIG_RANDOMIZE_IDENTITY_BASE
#define __identity_base         vm_layout.identity_base
#else
#define __identity_base         0UL
#endif
#define ident_map_size          vm_layout.identity_size

static inline unsigned long kaslr_offset(void)
{
        return __kaslr_offset;
}

extern int __kaslr_enabled;
static inline int kaslr_enabled(void)
{
        if (IS_ENABLED(CONFIG_RANDOMIZE_BASE))
                return __kaslr_enabled;
        return 0;
}

#define __PAGE_OFFSET           __identity_base
#define PAGE_OFFSET             __PAGE_OFFSET

#ifdef __DECOMPRESSOR

#define __pa_nodebug(x)         ((unsigned long)(x))
#define __pa(x)                 __pa_nodebug(x)
#define __pa32(x)               __pa(x)
#define __va(x)                 ((void *)(unsigned long)(x))

#else /* __DECOMPRESSOR */

static inline unsigned long __pa_nodebug(unsigned long x)
{
        if (x < __kaslr_offset)
                return x - __identity_base;
        return x - __kaslr_offset + __kaslr_offset_phys;
}

#ifdef CONFIG_DEBUG_VIRTUAL

unsigned long __phys_addr(unsigned long x, bool is_31bit);

#else /* CONFIG_DEBUG_VIRTUAL */

static inline unsigned long __phys_addr(unsigned long x, bool is_31bit)
{
        return __pa_nodebug(x);
}

#endif /* CONFIG_DEBUG_VIRTUAL */

#define __pa(x)                 __phys_addr((unsigned long)(x), false)
#define __pa32(x)               __phys_addr((unsigned long)(x), true)
#define __va(x)                 ((void *)((unsigned long)(x) + __identity_base))

#endif /* __DECOMPRESSOR */

#define phys_to_pfn(phys)       ((phys) >> PAGE_SHIFT)
#define pfn_to_phys(pfn)        ((pfn) << PAGE_SHIFT)

#define phys_to_folio(phys)     page_folio(phys_to_page(phys))
#define folio_to_phys(page)     pfn_to_phys(folio_pfn(folio))

static inline void *pfn_to_virt(unsigned long pfn)
{
        return __va(pfn_to_phys(pfn));
}

static inline unsigned long virt_to_pfn(const void *kaddr)
{
        return phys_to_pfn(__pa(kaddr));
}

#define pfn_to_kaddr(pfn)       pfn_to_virt(pfn)

#define virt_to_page(kaddr)     pfn_to_page(virt_to_pfn(kaddr))
#define page_to_virt(page)      pfn_to_virt(page_to_pfn(page))

#define virt_addr_valid(kaddr)  pfn_valid(phys_to_pfn(__pa_nodebug((unsigned long)(kaddr))))

#define VM_DATA_DEFAULT_FLAGS   VM_DATA_FLAGS_NON_EXEC

#endif /* !__ASSEMBLER__ */

#include <asm-generic/memory_model.h>
#include <asm-generic/getorder.h>

#define AMODE31_SIZE            (3 * PAGE_SIZE)

#define KERNEL_IMAGE_SIZE       (512 * 1024 * 1024)
#define __NO_KASLR_START_KERNEL CONFIG_KERNEL_IMAGE_BASE
#define __NO_KASLR_END_KERNEL   (__NO_KASLR_START_KERNEL + KERNEL_IMAGE_SIZE)

#define TEXT_OFFSET             0x100000

#endif /* _S390_PAGE_H */