diff options
Diffstat (limited to 'kernel/arch/avr32/mm/ioremap.c')
-rw-r--r-- | kernel/arch/avr32/mm/ioremap.c | 93 |
1 files changed, 93 insertions, 0 deletions
diff --git a/kernel/arch/avr32/mm/ioremap.c b/kernel/arch/avr32/mm/ioremap.c new file mode 100644 index 000000000..7def0d84c --- /dev/null +++ b/kernel/arch/avr32/mm/ioremap.c @@ -0,0 +1,93 @@ +/* + * Copyright (C) 2004-2006 Atmel Corporation + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ +#include <linux/vmalloc.h> +#include <linux/mm.h> +#include <linux/module.h> +#include <linux/io.h> +#include <linux/slab.h> + +#include <asm/pgtable.h> +#include <asm/addrspace.h> + +/* + * Re-map an arbitrary physical address space into the kernel virtual + * address space. Needed when the kernel wants to access physical + * memory directly. + */ +void __iomem *__ioremap(unsigned long phys_addr, size_t size, + unsigned long flags) +{ + unsigned long addr; + struct vm_struct *area; + unsigned long offset, last_addr; + pgprot_t prot; + + /* + * Check if we can simply use the P4 segment. This area is + * uncacheable, so if caching/buffering is requested, we can't + * use it. + */ + if ((phys_addr >= P4SEG) && (flags == 0)) + return (void __iomem *)phys_addr; + + /* Don't allow wraparound or zero size */ + last_addr = phys_addr + size - 1; + if (!size || last_addr < phys_addr) + return NULL; + + /* + * XXX: When mapping regular RAM, we'd better make damn sure + * it's never used for anything else. But this is really the + * caller's responsibility... + */ + if (PHYSADDR(P2SEGADDR(phys_addr)) == phys_addr) + return (void __iomem *)P2SEGADDR(phys_addr); + + /* Mappings have to be page-aligned */ + offset = phys_addr & ~PAGE_MASK; + phys_addr &= PAGE_MASK; + size = PAGE_ALIGN(last_addr + 1) - phys_addr; + + prot = __pgprot(_PAGE_PRESENT | _PAGE_GLOBAL | _PAGE_RW | _PAGE_DIRTY + | _PAGE_ACCESSED | _PAGE_TYPE_SMALL | flags); + + /* + * Ok, go for it.. + */ + area = get_vm_area(size, VM_IOREMAP); + if (!area) + return NULL; + area->phys_addr = phys_addr; + addr = (unsigned long )area->addr; + if (ioremap_page_range(addr, addr + size, phys_addr, prot)) { + vunmap((void *)addr); + return NULL; + } + + return (void __iomem *)(offset + (char *)addr); +} +EXPORT_SYMBOL(__ioremap); + +void __iounmap(void __iomem *addr) +{ + struct vm_struct *p; + + if ((unsigned long)addr >= P4SEG) + return; + if (PXSEG(addr) == P2SEG) + return; + + p = remove_vm_area((void *)(PAGE_MASK & (unsigned long __force)addr)); + if (unlikely(!p)) { + printk (KERN_ERR "iounmap: bad address %p\n", addr); + return; + } + + kfree (p); +} +EXPORT_SYMBOL(__iounmap); |