// SPDX-License-Identifier: GPL-2.0
/*
 *  linux/arch/m68k/mm/kmap.c
 *
 *  Copyright (C) 1997 Roman Hodek
 *
 *  10/01/99 cleaned up the code and changing to the same interface
 *           used by other architectures                /Roman Zippel
 */

#include <linux/module.h>
#include <linux/mm.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>

#include <asm/setup.h>
#include <asm/page.h>
#include <asm/io.h>
#include <asm/tlbflush.h>

#undef DEBUG

/*
 * For 040/060 we can use the virtual memory area like other architectures,
 * but for 020/030 we want to use early termination page descriptors and we
 * can't mix this with normal page descriptors, so we have to copy that code
 * (mm/vmalloc.c) and return appropriately aligned addresses.
 */

#ifdef CPU_M68040_OR_M68060_ONLY

#define IO_SIZE         PAGE_SIZE

static inline struct vm_struct *get_io_area(unsigned long size)
{
        return get_vm_area(size, VM_IOREMAP);
}


static inline void free_io_area(void *addr)
{
        vfree((void *)(PAGE_MASK & (unsigned long)addr));
}

#else

#define IO_SIZE         PMD_SIZE

static struct vm_struct *iolist;

/*
 * __free_io_area unmaps nearly everything, so be careful
 * Currently it doesn't free pointer/page tables anymore but this
 * wasn't used anyway and might be added later.
 */
static void __free_io_area(void *addr, unsigned long size)
{
        unsigned long virtaddr = (unsigned long)addr;
        pgd_t *pgd_dir;
        p4d_t *p4d_dir;
        pud_t *pud_dir;
        pmd_t *pmd_dir;
        pte_t *pte_dir;

        while ((long)size > 0) {
                pgd_dir = pgd_offset_k(virtaddr);
                p4d_dir = p4d_offset(pgd_dir, virtaddr);
                pud_dir = pud_offset(p4d_dir, virtaddr);
                if (pud_bad(*pud_dir)) {
                        printk("iounmap: bad pud(%08lx)\n", pud_val(*pud_dir));
                        pud_clear(pud_dir);
                        return;
                }
                pmd_dir = pmd_offset(pud_dir, virtaddr);

#if CONFIG_PGTABLE_LEVELS == 3
                if (CPU_IS_020_OR_030) {
                        int pmd_type = pmd_val(*pmd_dir) & _DESCTYPE_MASK;

                        if (pmd_type == _PAGE_PRESENT) {
                                pmd_clear(pmd_dir);
                                virtaddr += PMD_SIZE;
                                size -= PMD_SIZE;

                        } else if (pmd_type == 0)
                                continue;
                }
#endif

                if (pmd_bad(*pmd_dir)) {
                        printk("iounmap: bad pmd (%08lx)\n", pmd_val(*pmd_dir));
                        pmd_clear(pmd_dir);
                        return;
                }
                pte_dir = pte_offset_kernel(pmd_dir, virtaddr);

                pte_val(*pte_dir) = 0;
                virtaddr += PAGE_SIZE;
                size -= PAGE_SIZE;
        }

        flush_tlb_all();
}

static struct vm_struct *get_io_area(unsigned long size)
{
        unsigned long addr;
        struct vm_struct **p, *tmp, *area;

        area = kmalloc_obj(*area);
        if (!area)
                return NULL;
        addr = KMAP_START;
        for (p = &iolist; (tmp = *p) ; p = &tmp->next) {
                if (size + addr < (unsigned long)tmp->addr)
                        break;
                if (addr > KMAP_END-size) {
                        kfree(area);
                        return NULL;
                }
                addr = tmp->size + (unsigned long)tmp->addr;
        }
        area->addr = (void *)addr;
        area->size = size + IO_SIZE;
        area->next = *p;
        *p = area;
        return area;
}

static inline void free_io_area(void *addr)
{
        struct vm_struct **p, *tmp;

        if (!addr)
                return;
        addr = (void *)((unsigned long)addr & -IO_SIZE);
        for (p = &iolist ; (tmp = *p) ; p = &tmp->next) {
                if (tmp->addr == addr) {
                        *p = tmp->next;
                        /* remove gap added in get_io_area() */
                        __free_io_area(tmp->addr, tmp->size - IO_SIZE);
                        kfree(tmp);
                        return;
                }
        }
}

#endif

/*
 * Map some physical address range into the kernel address space.
 */
/* Rewritten by Andreas Schwab to remove all races. */

void __iomem *__ioremap(unsigned long physaddr, unsigned long size, int cacheflag)
{
        struct vm_struct *area;
        unsigned long virtaddr, retaddr;
        long offset;
        pgd_t *pgd_dir;
        p4d_t *p4d_dir;
        pud_t *pud_dir;
        pmd_t *pmd_dir;
        pte_t *pte_dir;

        /*
         * Don't allow mappings that wrap..
         */
        if (!size || physaddr > (unsigned long)(-size))
                return NULL;

#ifdef CONFIG_AMIGA
        if (MACH_IS_AMIGA) {
                if ((physaddr >= 0x40000000) && (physaddr + size < 0x60000000)
                    && (cacheflag == IOMAP_NOCACHE_SER))
                        return (void __iomem *)physaddr;
        }
#endif
#ifdef CONFIG_VIRT
        if (MACH_IS_VIRT) {
                if (physaddr >= 0xff000000 && cacheflag == IOMAP_NOCACHE_SER)
                        return (void __iomem *)physaddr;
        }
#endif
#ifdef CONFIG_COLDFIRE
        if (__cf_internalio(physaddr))
                return (void __iomem *) physaddr;
#endif

#ifdef DEBUG
        printk("ioremap: 0x%lx,0x%lx(%d) - ", physaddr, size, cacheflag);
#endif
        /*
         * Mappings have to be aligned
         */
        offset = physaddr & (IO_SIZE - 1);
        physaddr &= -IO_SIZE;
        size = (size + offset + IO_SIZE - 1) & -IO_SIZE;

        /*
         * Ok, go for it..
         */
        area = get_io_area(size);
        if (!area)
                return NULL;

        virtaddr = (unsigned long)area->addr;
        retaddr = virtaddr + offset;
#ifdef DEBUG
        printk("0x%lx,0x%lx,0x%lx", physaddr, virtaddr, retaddr);
#endif

        /*
         * add cache and table flags to physical address
         */
        if (CPU_IS_040_OR_060) {
                physaddr |= (_PAGE_PRESENT | _PAGE_GLOBAL040 |
                             _PAGE_ACCESSED | _PAGE_DIRTY);
                switch (cacheflag) {
                case IOMAP_FULL_CACHING:
                        physaddr |= _PAGE_CACHE040;
                        break;
                case IOMAP_NOCACHE_SER:
                default:
                        physaddr |= _PAGE_NOCACHE_S;
                        break;
                case IOMAP_NOCACHE_NONSER:
                        physaddr |= _PAGE_NOCACHE;
                        break;
                case IOMAP_WRITETHROUGH:
                        physaddr |= _PAGE_CACHE040W;
                        break;
                }
        } else {
                physaddr |= (_PAGE_PRESENT | _PAGE_ACCESSED |
                             _PAGE_DIRTY | _PAGE_READWRITE);
                switch (cacheflag) {
                case IOMAP_NOCACHE_SER:
                case IOMAP_NOCACHE_NONSER:
                default:
                        physaddr |= _PAGE_NOCACHE030;
                        break;
                case IOMAP_FULL_CACHING:
                case IOMAP_WRITETHROUGH:
                        break;
                }
        }

        while ((long)size > 0) {
#ifdef DEBUG
                if (!(virtaddr & (PMD_SIZE-1)))
                        printk ("\npa=%#lx va=%#lx ", physaddr, virtaddr);
#endif
                pgd_dir = pgd_offset_k(virtaddr);
                p4d_dir = p4d_offset(pgd_dir, virtaddr);
                pud_dir = pud_offset(p4d_dir, virtaddr);
                pmd_dir = pmd_alloc(&init_mm, pud_dir, virtaddr);
                if (!pmd_dir) {
                        printk("ioremap: no mem for pmd_dir\n");
                        return NULL;
                }

#if CONFIG_PGTABLE_LEVELS == 3
                if (CPU_IS_020_OR_030) {
                        pmd_val(*pmd_dir) = physaddr;
                        physaddr += PMD_SIZE;
                        virtaddr += PMD_SIZE;
                        size -= PMD_SIZE;
                } else
#endif
                {
                        pte_dir = pte_alloc_kernel(pmd_dir, virtaddr);
                        if (!pte_dir) {
                                printk("ioremap: no mem for pte_dir\n");
                                return NULL;
                        }

                        pte_val(*pte_dir) = physaddr;
                        virtaddr += PAGE_SIZE;
                        physaddr += PAGE_SIZE;
                        size -= PAGE_SIZE;
                }
        }
#ifdef DEBUG
        printk("\n");
#endif
        flush_tlb_all();

        return (void __iomem *)retaddr;
}
EXPORT_SYMBOL(__ioremap);

/*
 * Unmap an ioremap()ed region again
 */
void iounmap(void __iomem *addr)
{
#ifdef CONFIG_AMIGA
        if (MACH_IS_AMIGA &&
            ((unsigned long)addr >= 0x40000000) &&
            ((unsigned long)addr < 0x60000000))
                return;
#endif
#ifdef CONFIG_VIRT
        if (MACH_IS_VIRT && (unsigned long)addr >= 0xff000000)
                return;
#endif
#ifdef CONFIG_COLDFIRE
        if (cf_internalio(addr))
                return;
#endif
        free_io_area((__force void *)addr);
}
EXPORT_SYMBOL(iounmap);

/*
 * Set new cache mode for some kernel address space.
 * The caller must push data for that range itself, if such data may already
 * be in the cache.
 */
void kernel_set_cachemode(void *addr, unsigned long size, int cmode)
{
        unsigned long virtaddr = (unsigned long)addr;
        pgd_t *pgd_dir;
        p4d_t *p4d_dir;
        pud_t *pud_dir;
        pmd_t *pmd_dir;
        pte_t *pte_dir;

        if (CPU_IS_040_OR_060) {
                switch (cmode) {
                case IOMAP_FULL_CACHING:
                        cmode = _PAGE_CACHE040;
                        break;
                case IOMAP_NOCACHE_SER:
                default:
                        cmode = _PAGE_NOCACHE_S;
                        break;
                case IOMAP_NOCACHE_NONSER:
                        cmode = _PAGE_NOCACHE;
                        break;
                case IOMAP_WRITETHROUGH:
                        cmode = _PAGE_CACHE040W;
                        break;
                }
        } else {
                switch (cmode) {
                case IOMAP_NOCACHE_SER:
                case IOMAP_NOCACHE_NONSER:
                default:
                        cmode = _PAGE_NOCACHE030;
                        break;
                case IOMAP_FULL_CACHING:
                case IOMAP_WRITETHROUGH:
                        cmode = 0;
                }
        }

        while ((long)size > 0) {
                pgd_dir = pgd_offset_k(virtaddr);
                p4d_dir = p4d_offset(pgd_dir, virtaddr);
                pud_dir = pud_offset(p4d_dir, virtaddr);
                if (pud_bad(*pud_dir)) {
                        printk("iocachemode: bad pud(%08lx)\n", pud_val(*pud_dir));
                        pud_clear(pud_dir);
                        return;
                }
                pmd_dir = pmd_offset(pud_dir, virtaddr);

#if CONFIG_PGTABLE_LEVELS == 3
                if (CPU_IS_020_OR_030) {
                        unsigned long pmd = pmd_val(*pmd_dir);

                        if ((pmd & _DESCTYPE_MASK) == _PAGE_PRESENT) {
                                *pmd_dir = __pmd((pmd & _CACHEMASK040) | cmode);
                                virtaddr += PMD_SIZE;
                                size -= PMD_SIZE;
                                continue;
                        }
                }
#endif

                if (pmd_bad(*pmd_dir)) {
                        printk("iocachemode: bad pmd (%08lx)\n", pmd_val(*pmd_dir));
                        pmd_clear(pmd_dir);
                        return;
                }
                pte_dir = pte_offset_kernel(pmd_dir, virtaddr);

                pte_val(*pte_dir) = (pte_val(*pte_dir) & _CACHEMASK040) | cmode;
                virtaddr += PAGE_SIZE;
                size -= PAGE_SIZE;
        }

        flush_tlb_all();
}
EXPORT_SYMBOL(kernel_set_cachemode);