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/*

 * arch/or32/mm/ioremap.c

 *

 * Re-map IO memory to kernel address space so that we can access it.

 * Needed for memory-mapped I/O devices mapped outside our normal DRAM

 * window (that is, all memory-mapped I/O devices).

 *

 * (C) Copyright 1995 1996 Linus Torvalds

 * CRIS-port by Axis Communications AB

 */

#include <linux/vmalloc.h>

#include <asm/io.h>

#include <asm/pgalloc.h>

#include <asm/cacheflush.h>

#include <asm/tlbflush.h>

#include <asm/kmap_types.h>

#include <asm/fixmap.h>

#include <asm/bug.h>

#include <linux/sched.h>

/* __PHX__ cleanup, check */

#define __READABLE   ( _PAGE_ALL | _PAGE_URE | _PAGE_SRE )

#define __WRITEABLE  ( _PAGE_WRITE )

#define _PAGE_GLOBAL ( 0 )

#define _PAGE_KERNEL ( _PAGE_ALL | _PAGE_SRE | _PAGE_SWE | _PAGE_SHARED | _PAGE_DIRTY | _PAGE_EXEC )

extern int mem_init_done;

/* bt ioremaped lenghts */

static unsigned int bt_ioremapped_len[NR_FIX_BTMAPS] __initdata =

 {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};

extern inline void remap_area_pte(pte_t * pte, unsigned long address, unsigned long size,

        unsigned long phys_addr, unsigned long flags)

{

        unsigned long end;

        address &= ~PMD_MASK;

        end = address + size;

        if (end > PMD_SIZE)

                end = PMD_SIZE;

        if (address >= end)

                BUG();

        do {

                if (!pte_none(*pte)) {

                        printk("remap_area_pte: page already exists\n");

                        BUG();

                }

                set_pte(pte, mk_pte_phys(phys_addr, __pgprot(_PAGE_PRESENT | __READABLE |

                                                             __WRITEABLE | _PAGE_GLOBAL |

                                                             _PAGE_KERNEL | flags)));

                address += PAGE_SIZE;

                phys_addr += PAGE_SIZE;

                pte++;

        } while (address && (address < end));

}

static inline int remap_area_pmd(pmd_t * pmd, unsigned long address, unsigned long size,

        unsigned long phys_addr, unsigned long flags)

{

        unsigned long end;

        address &= ~PGDIR_MASK;

        end = address + size;

        if (end > PGDIR_SIZE)

                end = PGDIR_SIZE;

        phys_addr -= address;

        if (address >= end)

                BUG();

        do {

                pte_t * pte = pte_alloc_kernel(pmd, address);

                if (!pte)

                        return -ENOMEM;

                remap_area_pte(pte, address, end - address, address + phys_addr, flags);

                address = (address + PMD_SIZE) & PMD_MASK;

                pmd++;

        } while (address && (address < end));

        return 0;

}

static int remap_area_pages(unsigned long address, unsigned long phys_addr,

                                 unsigned long size, unsigned long flags)

{

        int error;

        pgd_t * dir;

        unsigned long end = address + size;

        phys_addr -= address;

        dir = pgd_offset(&init_mm, address);

        flush_cache_all();

        if (address >= end)

                BUG();

        spin_lock(&init_mm.page_table_lock);

        do {

                pmd_t *pmd;

                pmd = pmd_alloc(&init_mm, dir, address);

                error = -ENOMEM;

                if (!pmd)

                        break;

                if (remap_area_pmd(pmd, address, end - address,

                                   phys_addr + address, flags))

                        break;

                error = 0;

                address = (address + PGDIR_SIZE) & PGDIR_MASK;

                dir++;

        } while (address && (address < end));

        spin_unlock(&init_mm.page_table_lock);

        flush_tlb_all();

        return error;

}

/*

 * IO remapping core to use when system is running

 */

void *ioremap_core(unsigned long phys_addr, unsigned long size,

                   unsigned long flags)

{

        struct vm_struct * area;

        void * addr;

        area = get_vm_area(size, VM_IOREMAP);

        if (!area)

                return NULL;

        addr = area->addr;

        if (remap_area_pages((unsigned long) addr, phys_addr, size, flags)) {

                vfree(addr);

                return NULL;

        }

        return addr;

}

/*

 * Boot-time IO remapping core to use

 */

static void __init *bt_ioremap_core(unsigned long phys_addr, unsigned long size,

                                    unsigned long flags)

{

        unsigned int nrpages;

        unsigned int i;

        unsigned int nr_free;

        unsigned int idx;

        /*

         * Mappings have to fit in the FIX_BTMAP area.

         */

        nrpages = size >> PAGE_SHIFT;

        if (nrpages > NR_FIX_BTMAPS)

                return NULL;

        /*

         * Find a big enough gap in NR_FIX_BTMAPS

         */

        idx = FIX_BTMAP_BEGIN;

        for(i = 0, nr_free = 0; i < NR_FIX_BTMAPS; i++) {

                if(!bt_ioremapped_len[i])

                        nr_free++;

                else {

                        nr_free = 0;

                        idx = FIX_BTMAP_BEGIN - i;

                        i += bt_ioremapped_len[i] - 2;

                }

                if(nr_free == nrpages)

                        break;

        }

        if(nr_free < nrpages)

                return NULL;

        bt_ioremapped_len[FIX_BTMAP_BEGIN - idx] = nrpages;

        /*

         * Ok, go for it..

         */

        for(i = idx; nrpages > 0; i--, nrpages--) {

                set_fixmap_nocache(i, phys_addr);

                phys_addr += PAGE_SIZE;

        }

        return (void *)fix_to_virt(idx);

}

static void __init bt_iounmap(void *addr)

{

        unsigned long virt_addr;

        unsigned int nr_pages;

        unsigned int idx;

        virt_addr = (unsigned long)addr;

        idx = virt_to_fix(virt_addr);

        nr_pages = bt_ioremapped_len[FIX_BTMAP_BEGIN - idx];

        bt_ioremapped_len[FIX_BTMAP_BEGIN - idx] = 0;

        while (nr_pages > 0) {

                clear_fixmap(idx);

                --idx;

                --nr_pages;

        }

}

/*

 * Generic mapping function (not visible outside):

 */

/*

 * Remap an arbitrary physical address space into the kernel virtual

 * address space. Needed when the kernel wants to access high addresses

 * directly.

 *

 * NOTE! We need to allow non-page-aligned mappings too: we will obviously

 * have to convert them into an offset in a page-aligned mapping, but the

 * caller shouldn't need to know that small detail.

 */

void * __ioremap(unsigned long phys_addr, unsigned long size, unsigned long flags)

{

        void * addr;

        unsigned long offset, last_addr;

        /* Don't allow wraparound or zero size */

        last_addr = phys_addr + size - 1;

        if (!size || last_addr < phys_addr)

                return NULL;

#if 0

        /* TODO: Here we can put checks for driver-writer abuse...  */

        /*

         * Don't remap the low PCI/ISA area, it's always mapped..

         */

        if (phys_addr >= 0xA0000 && last_addr < 0x100000)

                return phys_to_virt(phys_addr);

        /*

         * Don't allow anybody to remap normal RAM that we're using..

         */

        if (phys_addr < virt_to_phys(high_memory)) {

                char *t_addr, *t_end;

                struct page *page;

                t_addr = __va(phys_addr);

                t_end = t_addr + (size - 1);

                for(page = virt_to_page(t_addr); page <= virt_to_page(t_end); page++)

                        if(!PageReserved(page))

                                return NULL;

        }

#endif

        /*

         * Mappings have to be page-aligned

         */

        offset = phys_addr & ~PAGE_MASK;

        phys_addr &= PAGE_MASK;

        size = PAGE_ALIGN(last_addr+1) - phys_addr;

        /*

         * Ok, go for it..

         */

        if(mem_init_done)

                addr = ioremap_core(phys_addr, size, flags);

        else

                addr = bt_ioremap_core(phys_addr, size, flags);

        return (void *) (offset + (char *)addr);

}

static inline int is_bt_ioremapped(void *addr)

{

        unsigned long a = (unsigned long)addr;

        return (a < FIXADDR_TOP) && (a >= FIXADDR_BOOT_START);

}

void iounmap(void *addr)

{

        if(is_bt_ioremapped(addr))

                return bt_iounmap(addr);

        if (addr > high_memory)

                return vfree((void *) (PAGE_MASK & (unsigned long) addr));

}

//RGD stolen from PPC probably doesn't work on or32 not called right now

void __iomem *ioport_map(unsigned long port, unsigned int len)

{

        return (void __iomem *) (port + IO_BASE);

}

void ioport_unmap(void __iomem *addr)

{

        /* Nothing to do */

}