/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_HIGHMEM_INTERNAL_H
#define _LINUX_HIGHMEM_INTERNAL_H

/*
 * Outside of CONFIG_HIGHMEM to support X86 32bit iomap_atomic() cruft.
 */
#ifdef CONFIG_KMAP_LOCAL
void *____kmap_local_pfn_prot(unsigned long pfn, pgprot_t prot, enum kmap_slots slot);
void *__kmap_local_pfn_prot(unsigned long pfn, pgprot_t prot);
void *__kmap_local_page_prot(struct page *page, pgprot_t prot);
void kunmap_local_indexed(const void *vaddr);
void kmap_local_fork(struct task_struct *tsk);
void __kmap_local_sched_out(void);
void __kmap_local_sched_in(void);
static inline void kmap_assert_nomap(void)
{
    DEBUG_LOCKS_WARN_ON(current->kmap_ctrl.idx);
}
#else
static inline void kmap_local_fork(struct task_struct *tsk) { }
static inline void kmap_assert_nomap(void) { }
#endif

#ifdef CONFIG_KMAP_LOCAL_PER_CPU
void __kmap_local_per_cpu_sched_out(void);
void __kmap_local_per_cpu_sched_in(void);
#endif

#if defined(CONFIG_HIGHMEM) || defined(CONFIG_KMAP_LOCAL_PER_CPU)
struct page *__kmap_to_page(void *addr);
#endif

static inline struct page *kmap_to_page(void *addr)
{
#if defined(CONFIG_HIGHMEM) || defined(CONFIG_KMAP_LOCAL_PER_CPU)
    return __kmap_to_page(addr);
#else
    return virt_to_page(addr);
#endif
}

#if defined(CONFIG_HIGHMEM) || defined(CONFIG_PAX_KERNSEAL)
#include <asm/highmem.h>
#endif

#ifdef CONFIG_HIGHMEM
#ifndef ARCH_HAS_KMAP_FLUSH_TLB
static inline void kmap_flush_tlb(unsigned long addr) { }
#endif

#ifndef kmap_prot
#define kmap_prot PAGE_KERNEL
#endif

void *kmap_high(struct page *page);
void kunmap_high(struct page *page);
void __kmap_flush_unused(void);

static inline void *kmap(struct page *page)
{
    void *addr;

    might_sleep();
    if (!PageHighMem(page))
        addr = page_address(page);
    else
        addr = kmap_high(page);
    kmap_flush_tlb((unsigned long)addr);
    return addr;
}

static inline void *kmap_noreport(struct page *page)
{
    return kmap(page);
}

static inline void kunmap(struct page *page)
{
    might_sleep();
    if (!PageHighMem(page))
        return;
    kunmap_high(page);
}

static inline void kmap_flush_unused(void)
{
    __kmap_flush_unused();
}

static inline void *kmap_local_page(struct page *page)
{
    return __kmap_local_page_prot(page, kmap_prot);
}

static inline void *kmap_local_page_user(struct page *page)
{
    return kmap_local_page(page);
}

static inline void *kmap_local_page_nested(struct page *page)
{
    return __kmap_local_page_prot(page, kmap_prot);
}

static inline void *kmap_local_page_nested_user(struct page *page)
{
    return kmap_local_page_nested(page);
}

static inline void *kmap_local_folio(struct folio *folio, size_t offset)
{
    struct page *page = folio_page(folio, offset / PAGE_SIZE);
    return __kmap_local_page_prot(page, kmap_prot) + offset % PAGE_SIZE;
}

static inline void *kmap_local_page_prot(struct page *page, pgprot_t prot)
{
    return __kmap_local_page_prot(page, prot);
}

static inline void *kmap_local_pfn(unsigned long pfn)
{
    return __kmap_local_pfn_prot(pfn, kmap_prot);
}

static inline void __kunmap_local(const void *vaddr)
{
    kunmap_local_indexed(vaddr);
}

static inline void __kunmap_local_nested(const void *vaddr)
{
    kunmap_local_indexed(vaddr);
}

static inline void *kmap_atomic_prot(struct page *page, pgprot_t prot)
{
    if (IS_ENABLED(CONFIG_PREEMPT_RT))
        migrate_disable();
    else
        preempt_disable();

    pagefault_disable();
    return __kmap_local_page_prot(page, prot);
}

static inline void *kmap_atomic(struct page *page)
{
    return kmap_atomic_prot(page, kmap_prot);
}

static inline void *kmap_atomic_pfn(unsigned long pfn)
{
    if (IS_ENABLED(CONFIG_PREEMPT_RT))
        migrate_disable();
    else
        preempt_disable();

    pagefault_disable();
    return __kmap_local_pfn_prot(pfn, kmap_prot);
}

static inline void __kunmap_atomic(const void *addr)
{
    kunmap_local_indexed(addr);
    pagefault_enable();
    if (IS_ENABLED(CONFIG_PREEMPT_RT))
        migrate_enable();
    else
        preempt_enable();
}

unsigned int __nr_free_highpages(void);
extern atomic_long_t _totalhigh_pages;

static inline unsigned int nr_free_highpages(void)
{
    return __nr_free_highpages();
}

static inline unsigned long totalhigh_pages(void)
{
    return (unsigned long)atomic_long_read(&_totalhigh_pages);
}

static inline void totalhigh_pages_add(long count)
{
    atomic_long_add(count, &_totalhigh_pages);
}

static inline bool is_kmap_addr(const void *x)
{
    unsigned long addr = (unsigned long)x;

    return (addr >= PKMAP_ADDR(0) && addr < PKMAP_ADDR(LAST_PKMAP)) ||
        (addr >= __fix_to_virt(FIX_KMAP_END) &&
         addr < __fix_to_virt(FIX_KMAP_BEGIN));
}
#else /* CONFIG_HIGHMEM */

#ifdef CONFIG_PAX_KERNSEAL
void *__kmap(struct page *page);
void __kunmap(struct page *page);
#endif

static inline void *kmap_noreport(struct page *page)
{
    might_sleep();
#ifdef CONFIG_PAX_KERNSEAL
    VM_BUG_ON_PAGE_ALWAYS(PageSealed(page), page);
    if (PageHidden(page))
        return __kmap(page);
#endif
    return page_address(page);
}

static inline void *kmap(struct page *page)
{
#ifdef CONFIG_PAX_KERNSEAL
    WARN_ONCE(PageSealed(page) || PageHidden(page), "PAX: unverified call to kmap for page %pS mapping %pS\n", page, page->mapping);
#endif
    return kmap_noreport(page);
}

static inline void kunmap_high(struct page *page) { }
static inline void kmap_flush_unused(void) { }

static inline void kunmap(struct page *page)
{
#ifdef ARCH_HAS_FLUSH_ON_KUNMAP
    kunmap_flush_on_unmap(page_address(page));
#endif
#ifdef CONFIG_PAX_KERNSEAL
    VM_BUG_ON_PAGE_ALWAYS(PageSealed(page), page);
    if (PageHidden(page))
        __kunmap(page);
#endif
}

static __always_inline void *kmap_local_page(struct page *page)
{
#ifdef CONFIG_PAX_KERNSEAL
    if (PageSealed(page) || PageHidden(page))
        return pax_expose_page(page);
#endif
    return page_address(page);
}

static __always_inline void *kmap_local_page_user(struct page *page)
{
#ifdef CONFIG_PAX_KERNSEAL
    if (PageSealed(page) || PageHidden(page))
        return pax_expose_page_user(page);
#endif
    return page_address(page);
}

static __always_inline void *kmap_local_page_nested(struct page *page)
{
#ifdef CONFIG_PAX_KERNSEAL
    if (PageSealed(page) || PageHidden(page))
        return pax_expose_page_nested(page);
#endif
    return page_address(page);
}

static __always_inline void *kmap_local_page_nested_user(struct page *page)
{
#ifdef CONFIG_PAX_KERNSEAL
    if (PageSealed(page) || PageHidden(page))
        return pax_expose_page_nested_user(page);
#endif
    return page_address(page);
}

static inline void *kmap_local_folio(struct folio *folio, size_t offset)
{
#ifdef CONFIG_PAX_KERNSEAL
    if (folio_test_sealed(folio) || folio_test_hidden(folio)) {
        struct page *page = folio_page(folio, offset / PAGE_SIZE);

        return pax_expose_page(page) + offset % PAGE_SIZE;
    }
#endif
    return folio_address(folio) + offset;
}

static inline void *kmap_local_page_prot(struct page *page, pgprot_t prot)
{
#ifdef CONFIG_PAX_KERNSEAL
    VM_BUG_ON_PAGE_ALWAYS(PageSealed(page), page);
    if (PageHidden(page))
        return pax_expose_page_prot(page, prot);
#endif
    return kmap_local_page(page);
}

static inline void *kmap_local_pfn(unsigned long pfn)
{
#ifdef CONFIG_PAX_KERNSEAL
    struct page *page = pfn_to_page(pfn);

    VM_BUG_ON_PAGE_ALWAYS(PageSealed(page), page);
    if (PageHidden(page)) {
BUG();
        return pax_expose_page(page);
    }
#endif
    return kmap_local_page(pfn_to_page(pfn));
}

static __always_inline void __kunmap_local(const void *addr)
{
#ifdef CONFIG_PAX_KERNSEAL
    struct page *page = kmap_to_page((void *)addr);

    if (PageSealed(page) || PageHidden(page))
        pax_hide_page(addr);
#endif
#ifdef ARCH_HAS_FLUSH_ON_KUNMAP
    kunmap_flush_on_unmap(PTR_ALIGN_DOWN(addr, PAGE_SIZE));
#endif
}

static __always_inline void __kunmap_local_nested(const void *addr)
{
#ifdef CONFIG_PAX_KERNSEAL
    struct page *page = kmap_to_page((void *)addr);

    if (PageSealed(page) || PageHidden(page))
        pax_hide_page_nested(addr);
#endif
#ifdef ARCH_HAS_FLUSH_ON_KUNMAP
    kunmap_flush_on_unmap(PTR_ALIGN_DOWN(addr, PAGE_SIZE));
#endif
}

static inline void *kmap_atomic(struct page *page)
{
    if (IS_ENABLED(CONFIG_PREEMPT_RT))
        migrate_disable();
    else
        preempt_disable();
    pagefault_disable();

#ifdef CONFIG_PAX_KERNSEAL
    if (PageSealed(page) || PageHidden(page))
        return pax_expose_page(page);
#endif

    return page_address(page);
}

static inline void *kmap_atomic_prot(struct page *page, pgprot_t prot)
{
    return kmap_atomic(page);
}

static inline void *kmap_atomic_pfn(unsigned long pfn)
{
    return kmap_atomic(pfn_to_page(pfn));
}

static inline void __kunmap_atomic(const void *addr)
{
#ifdef CONFIG_PAX_KERNSEAL
    struct page *page = kmap_to_page((void *)addr);

    if (PageSealed(page) || PageHidden(page))
        pax_hide_page(addr);
#endif
#ifdef ARCH_HAS_FLUSH_ON_KUNMAP
    kunmap_flush_on_unmap(PTR_ALIGN_DOWN(addr, PAGE_SIZE));
#endif
    pagefault_enable();
    if (IS_ENABLED(CONFIG_PREEMPT_RT))
        migrate_enable();
    else
        preempt_enable();
}

static inline unsigned int nr_free_highpages(void) { return 0; }
static inline unsigned long totalhigh_pages(void) { return 0UL; }

static inline bool is_kmap_addr(const void *x)
{
    return false;
}

#endif /* CONFIG_HIGHMEM */

/**
 * kunmap_atomic - Unmap the virtual address mapped by kmap_atomic() - deprecated!
 * @__addr:       Virtual address to be unmapped
 *
 * Unmaps an address previously mapped by kmap_atomic() and re-enables
 * pagefaults. Depending on PREEMP_RT configuration, re-enables also
 * migration and preemption. Users should not count on these side effects.
 *
 * Mappings should be unmapped in the reverse order that they were mapped.
 * See kmap_local_page() for details on nesting.
 *
 * @__addr can be any address within the mapped page, so there is no need
 * to subtract any offset that has been added. In contrast to kunmap(),
 * this function takes the address returned from kmap_atomic(), not the
 * page passed to it. The compiler will warn you if you pass the page.
 */
#define kunmap_atomic(__addr)                    \
do {                                \
    BUILD_BUG_ON(__same_type((__addr), struct page *));    \
    __kunmap_atomic(__addr);                \
} while (0)

/**
 * kunmap_local - Unmap a page mapped via kmap_local_page().
 * @__addr: An address within the page mapped
 *
 * @__addr can be any address within the mapped page.  Commonly it is the
 * address return from kmap_local_page(), but it can also include offsets.
 *
 * Unmapping should be done in the reverse order of the mapping.  See
 * kmap_local_page() for details.
 */
#define kunmap_local(__addr)                    \
do {                                \
    BUILD_BUG_ON(__same_type((__addr), struct page *));    \
    __kunmap_local(__addr);                    \
} while (0)

#define kunmap_local_nested(__addr)                \
do {                                \
    BUILD_BUG_ON(__same_type((__addr), struct page *));    \
    __kunmap_local_nested(__addr);                \
} while (0)

#endif