/*
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Copyright (C) 2009, Wind River Systems Inc
 * Implemented by fredrik.markstrom@gmail.com and ivarholmqvist@gmail.com
 */

#include <linux/export.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/fs.h>
#include <linux/pagemap.h>

#include <asm/cacheflush.h>
#include <asm/cpuinfo.h>

static void __flush_dcache(unsigned long start, unsigned long end)
{
        unsigned long addr;

        start &= ~(cpuinfo.dcache_line_size - 1);
        end += (cpuinfo.dcache_line_size - 1);
        end &= ~(cpuinfo.dcache_line_size - 1);

        if (end > start + cpuinfo.dcache_size)
                end = start + cpuinfo.dcache_size;

        for (addr = start; addr < end; addr += cpuinfo.dcache_line_size) {
                __asm__ __volatile__ ("   flushd 0(%0)\n"
                                        : /* Outputs */
                                        : /* Inputs  */ "r"(addr)
                                        /* : No clobber */);
        }
}

static void __invalidate_dcache(unsigned long start, unsigned long end)
{
        unsigned long addr;

        start &= ~(cpuinfo.dcache_line_size - 1);
        end += (cpuinfo.dcache_line_size - 1);
        end &= ~(cpuinfo.dcache_line_size - 1);

        for (addr = start; addr < end; addr += cpuinfo.dcache_line_size) {
                __asm__ __volatile__ ("   initda 0(%0)\n"
                                        : /* Outputs */
                                        : /* Inputs  */ "r"(addr)
                                        /* : No clobber */);
        }
}

static void __flush_icache(unsigned long start, unsigned long end)
{
        unsigned long addr;

        start &= ~(cpuinfo.icache_line_size - 1);
        end += (cpuinfo.icache_line_size - 1);
        end &= ~(cpuinfo.icache_line_size - 1);

        if (end > start + cpuinfo.icache_size)
                end = start + cpuinfo.icache_size;

        for (addr = start; addr < end; addr += cpuinfo.icache_line_size) {
                __asm__ __volatile__ ("   flushi %0\n"
                                        : /* Outputs */
                                        : /* Inputs  */ "r"(addr)
                                        /* : No clobber */);
        }
        __asm__ __volatile(" flushp\n");
}

static void flush_aliases(struct address_space *mapping, struct folio *folio)
{
        struct mm_struct *mm = current->active_mm;
        struct vm_area_struct *vma;
        unsigned long flags;
        pgoff_t pgoff;
        unsigned long nr = folio_nr_pages(folio);

        pgoff = folio->index;

        flush_dcache_mmap_lock_irqsave(mapping, flags);
        vma_interval_tree_foreach(vma, &mapping->i_mmap, pgoff, pgoff + nr - 1) {
                unsigned long start;

                if (vma->vm_mm != mm)
                        continue;
                if (!(vma->vm_flags & VM_MAYSHARE))
                        continue;

                start = vma->vm_start + ((pgoff - vma->vm_pgoff) << PAGE_SHIFT);
                flush_cache_range(vma, start, start + nr * PAGE_SIZE);
        }
        flush_dcache_mmap_unlock_irqrestore(mapping, flags);
}

void flush_cache_all(void)
{
        __flush_dcache(0, cpuinfo.dcache_size);
        __flush_icache(0, cpuinfo.icache_size);
}

void flush_cache_mm(struct mm_struct *mm)
{
        flush_cache_all();
}

void flush_cache_dup_mm(struct mm_struct *mm)
{
        flush_cache_all();
}

void flush_icache_range(unsigned long start, unsigned long end)
{
        __flush_dcache(start, end);
        __flush_icache(start, end);
}

void flush_dcache_range(unsigned long start, unsigned long end)
{
        __flush_dcache(start, end);
        __flush_icache(start, end);
}
EXPORT_SYMBOL(flush_dcache_range);

void invalidate_dcache_range(unsigned long start, unsigned long end)
{
        __invalidate_dcache(start, end);
}
EXPORT_SYMBOL(invalidate_dcache_range);

void flush_cache_range(struct vm_area_struct *vma, unsigned long start,
                        unsigned long end)
{
        __flush_dcache(start, end);
        if (vma == NULL || (vma->vm_flags & VM_EXEC))
                __flush_icache(start, end);
}

void flush_icache_pages(struct vm_area_struct *vma, struct page *page,
                unsigned int nr)
{
        unsigned long start = (unsigned long) page_address(page);
        unsigned long end = start + nr * PAGE_SIZE;

        __flush_dcache(start, end);
        __flush_icache(start, end);
}

void flush_cache_page(struct vm_area_struct *vma, unsigned long vmaddr,
                        unsigned long pfn)
{
        unsigned long start = vmaddr;
        unsigned long end = start + PAGE_SIZE;

        __flush_dcache(start, end);
        if (vma->vm_flags & VM_EXEC)
                __flush_icache(start, end);
}

static void __flush_dcache_folio(struct folio *folio)
{
        /*
         * Writeback any data associated with the kernel mapping of this
         * page.  This ensures that data in the physical page is mutually
         * coherent with the kernels mapping.
         */
        unsigned long start = (unsigned long)folio_address(folio);

        __flush_dcache(start, start + folio_size(folio));
}

void flush_dcache_folio(struct folio *folio)
{
        struct address_space *mapping;

        /*
         * The zero page is never written to, so never has any dirty
         * cache lines, and therefore never needs to be flushed.
         */
        if (is_zero_pfn(folio_pfn(folio)))
                return;

        mapping = folio_flush_mapping(folio);

        /* Flush this page if there are aliases. */
        if (mapping && !mapping_mapped(mapping)) {
                clear_bit(PG_dcache_clean, &folio->flags.f);
        } else {
                __flush_dcache_folio(folio);
                if (mapping) {
                        unsigned long start = (unsigned long)folio_address(folio);
                        flush_aliases(mapping, folio);
                        flush_icache_range(start, start + folio_size(folio));
                }
                set_bit(PG_dcache_clean, &folio->flags.f);
        }
}
EXPORT_SYMBOL(flush_dcache_folio);

void flush_dcache_page(struct page *page)
{
        flush_dcache_folio(page_folio(page));
}
EXPORT_SYMBOL(flush_dcache_page);

void update_mmu_cache_range(struct vm_fault *vmf, struct vm_area_struct *vma,
                unsigned long address, pte_t *ptep, unsigned int nr)
{
        pte_t pte = *ptep;
        unsigned long pfn = pte_pfn(pte);
        struct folio *folio;
        struct address_space *mapping;

        reload_tlb_page(vma, address, pte);

        if (!pfn_valid(pfn))
                return;

        /*
        * The zero page is never written to, so never has any dirty
        * cache lines, and therefore never needs to be flushed.
        */
        if (is_zero_pfn(pfn))
                return;

        folio = page_folio(pfn_to_page(pfn));
        if (!test_and_set_bit(PG_dcache_clean, &folio->flags.f))
                __flush_dcache_folio(folio);

        mapping = folio_flush_mapping(folio);
        if (mapping) {
                flush_aliases(mapping, folio);
                if (vma->vm_flags & VM_EXEC)
                        flush_icache_pages(vma, &folio->page,
                                        folio_nr_pages(folio));
        }
}

void copy_user_page(void *vto, void *vfrom, unsigned long vaddr,
                    struct page *to)
{
        __flush_dcache(vaddr, vaddr + PAGE_SIZE);
        __flush_icache(vaddr, vaddr + PAGE_SIZE);
        copy_page(vto, vfrom);
        __flush_dcache((unsigned long)vto, (unsigned long)vto + PAGE_SIZE);
        __flush_icache((unsigned long)vto, (unsigned long)vto + PAGE_SIZE);
}

void clear_user_page(void *addr, unsigned long vaddr, struct page *page)
{
        __flush_dcache(vaddr, vaddr + PAGE_SIZE);
        __flush_icache(vaddr, vaddr + PAGE_SIZE);
        clear_page(addr);
        __flush_dcache((unsigned long)addr, (unsigned long)addr + PAGE_SIZE);
        __flush_icache((unsigned long)addr, (unsigned long)addr + PAGE_SIZE);
}

void copy_from_user_page(struct vm_area_struct *vma, struct page *page,
                        unsigned long user_vaddr,
                        void *dst, void *src, int len)
{
        flush_cache_page(vma, user_vaddr, page_to_pfn(page));
        memcpy(dst, src, len);
        __flush_dcache((unsigned long)src, (unsigned long)src + len);
        if (vma->vm_flags & VM_EXEC)
                __flush_icache((unsigned long)src, (unsigned long)src + len);
}

void copy_to_user_page(struct vm_area_struct *vma, struct page *page,
                        unsigned long user_vaddr,
                        void *dst, void *src, int len)
{
        flush_cache_page(vma, user_vaddr, page_to_pfn(page));
        memcpy(dst, src, len);
        __flush_dcache((unsigned long)dst, (unsigned long)dst + len);
        if (vma->vm_flags & VM_EXEC)
                __flush_icache((unsigned long)dst, (unsigned long)dst + len);
}