diff options
Diffstat (limited to 'kernel/arch/m32r/mm/ioremap.c')
| -rw-r--r-- | kernel/arch/m32r/mm/ioremap.c | 111 |
1 files changed, 111 insertions, 0 deletions
diff --git a/kernel/arch/m32r/mm/ioremap.c b/kernel/arch/m32r/mm/ioremap.c new file mode 100644 index 000000000..5152c4e6a --- /dev/null +++ b/kernel/arch/m32r/mm/ioremap.c @@ -0,0 +1,111 @@ +/* + * linux/arch/m32r/mm/ioremap.c + * + * Copyright (c) 2001, 2002 Hiroyuki Kondo + * + * Taken from mips version. + * (C) Copyright 1995 1996 Linus Torvalds + * (C) Copyright 2001 Ralf Baechle + */ + +/* + * 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/module.h> +#include <asm/addrspace.h> +#include <asm/byteorder.h> + +#include <linux/vmalloc.h> +#include <linux/io.h> +#include <asm/pgalloc.h> + +/* + * 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. + */ + +#define IS_LOW512(addr) (!((unsigned long)(addr) & ~0x1fffffffUL)) + +void __iomem * +__ioremap(unsigned long phys_addr, unsigned long size, unsigned long flags) +{ + void __iomem * addr; + struct vm_struct * area; + unsigned long offset, last_addr; + pgprot_t pgprot; + + /* Don't allow wraparound or zero size */ + last_addr = phys_addr + size - 1; + if (!size || last_addr < phys_addr) + return NULL; + + /* + * Map objects in the low 512mb of address space using KSEG1, otherwise + * map using page tables. + */ + if (IS_LOW512(phys_addr) && IS_LOW512(phys_addr + size - 1)) + return (void *) KSEG1ADDR(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; + } + + pgprot = __pgprot(_PAGE_GLOBAL | _PAGE_PRESENT | _PAGE_READ + | _PAGE_WRITE | flags); + + /* + * 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.. + */ + area = get_vm_area(size, VM_IOREMAP); + if (!area) + return NULL; + area->phys_addr = phys_addr; + addr = (void __iomem *) area->addr; + if (ioremap_page_range((unsigned long)addr, (unsigned long)addr + size, + phys_addr, pgprot)) { + vunmap((void __force *) addr); + return NULL; + } + + return (void __iomem *) (offset + (char __iomem *)addr); +} + +#define IS_KSEG1(addr) (((unsigned long)(addr) & ~0x1fffffffUL) == KSEG1) + +void iounmap(volatile void __iomem *addr) +{ + if (!IS_KSEG1(addr)) + vfree((void *) (PAGE_MASK & (unsigned long) addr)); +} + |