/*
 * arch/sh/mm/ioremap.c
 *
 * (C) Copyright 1995 1996 Linus Torvalds
 * (C) Copyright 2005 - 2010  Paul Mundt
 *
 * Re-map IO memory to kernel address space so that we can access it.
 * This is needed for high PCI addresses that aren't mapped in the
 * 640k-1MB IO memory area on PC's
 *
 * 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.
 */
#include <linux/vmalloc.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/mm.h>
#include <linux/pci.h>
#include <linux/io.h>
#include <asm/io_trapped.h>
#include <asm/page.h>
#include <asm/pgalloc.h>
#include <asm/addrspace.h>
#include <asm/cacheflush.h>
#include <asm/tlbflush.h>
#include <asm/mmu.h>
#include "ioremap.h"

/*
 * On 32-bit SH, we traditionally have the whole physical address space mapped
 * at all times (as MIPS does), so "ioremap()" and "iounmap()" do not need to do
 * anything but place the address in the proper segment.  This is true for P1
 * and P2 addresses, as well as some P3 ones.  However, most of the P3 addresses
 * and newer cores using extended addressing need to map through page tables, so
 * the ioremap() implementation becomes a bit more complicated.
 */
#ifdef CONFIG_29BIT
static void __iomem *
__ioremap_29bit(phys_addr_t offset, unsigned long size, pgprot_t prot)
{
        phys_addr_t last_addr = offset + size - 1;

        /*
         * For P1 and P2 space this is trivial, as everything is already
         * mapped. Uncached access for P1 addresses are done through P2.
         * In the P3 case or for addresses outside of the 29-bit space,
         * mapping must be done by the PMB or by using page tables.
         */
        if (likely(PXSEG(offset) < P3SEG && PXSEG(last_addr) < P3SEG)) {
                u64 flags = pgprot_val(prot);

                /*
                 * Anything using the legacy PTEA space attributes needs
                 * to be kicked down to page table mappings.
                 */
                if (unlikely(flags & _PAGE_PCC_MASK))
                        return NULL;
                if (unlikely(flags & _PAGE_CACHABLE))
                        return (void __iomem *)P1SEGADDR(offset);

                return (void __iomem *)P2SEGADDR(offset);
        }

        /* P4 above the store queues are always mapped. */
        if (unlikely(offset >= P3_ADDR_MAX))
                return (void __iomem *)P4SEGADDR(offset);

        return NULL;
}
#else
#define __ioremap_29bit(offset, size, prot)             NULL
#endif /* CONFIG_29BIT */

void __iomem __ref *ioremap_prot(phys_addr_t phys_addr, size_t size,
                                 pgprot_t pgprot)
{
        void __iomem *mapped;

        mapped = __ioremap_trapped(phys_addr, size);
        if (mapped)
                return mapped;

        mapped = __ioremap_29bit(phys_addr, size, pgprot);
        if (mapped)
                return mapped;

        /*
         * If we can't yet use the regular approach, go the fixmap route.
         */
        if (!mem_init_done)
                return ioremap_fixed(phys_addr, size, pgprot);

        /*
         * First try to remap through the PMB.
         * PMB entries are all pre-faulted.
         */
        mapped = pmb_remap_caller(phys_addr, size, pgprot,
                        __builtin_return_address(0));
        if (mapped && !IS_ERR(mapped))
                return mapped;

        return generic_ioremap_prot(phys_addr, size, pgprot);
}
EXPORT_SYMBOL(ioremap_prot);

/*
 * Simple checks for non-translatable mappings.
 */
static inline int iomapping_nontranslatable(unsigned long offset)
{
#ifdef CONFIG_29BIT
        /*
         * In 29-bit mode this includes the fixed P1/P2 areas, as well as
         * parts of P3.
         */
        if (PXSEG(offset) < P3SEG || offset >= P3_ADDR_MAX)
                return 1;
#endif

        return 0;
}

void iounmap(volatile void __iomem *addr)
{
        unsigned long vaddr = (unsigned long __force)addr;

        /*
         * Nothing to do if there is no translatable mapping.
         */
        if (iomapping_nontranslatable(vaddr))
                return;

        /*
         * There's no VMA if it's from an early fixed mapping.
         */
        if (iounmap_fixed((void __iomem *)addr) == 0)
                return;

        /*
         * If the PMB handled it, there's nothing else to do.
         */
        if (pmb_unmap((void __iomem *)addr) == 0)
                return;

        generic_iounmap(addr);
}
EXPORT_SYMBOL(iounmap);