/Ethereal-msm8939-beta9/arch/metag/mm/ioremap.c
https://bitbucket.org/MilosStamenkovic95/etherealos · C · 89 lines · 52 code · 11 blank · 26 comment · 7 complexity · c2e4aab6076c9fea1723f5ec2f88f77a MD5 · raw file
- /*
- * 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).
- *
- * Copyright (C) 1995,1996 Linus Torvalds
- *
- * Meta port based on CRIS-port by Axis Communications AB
- */
- #include <linux/vmalloc.h>
- #include <linux/io.h>
- #include <linux/export.h>
- #include <linux/slab.h>
- #include <linux/mm.h>
- #include <asm/pgtable.h>
- /*
- * 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 __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;
- /* Don't allow wraparound or zero size */
- last_addr = phys_addr + size - 1;
- if (!size || last_addr < phys_addr)
- return NULL;
- /* Custom region addresses are accessible and uncached by default. */
- if (phys_addr >= LINSYSCUSTOM_BASE &&
- phys_addr < (LINSYSCUSTOM_BASE + LINSYSCUSTOM_LIMIT))
- return (__force void __iomem *) 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_WRITE | _PAGE_DIRTY |
- _PAGE_ACCESSED | _PAGE_KERNEL | _PAGE_CACHE_WIN0 |
- 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 (__force void __iomem *) (offset + (char *)addr);
- }
- EXPORT_SYMBOL(__ioremap);
- void __iounmap(void __iomem *addr)
- {
- struct vm_struct *p;
- if ((__force unsigned long)addr >= LINSYSCUSTOM_BASE &&
- (__force unsigned long)addr < (LINSYSCUSTOM_BASE +
- LINSYSCUSTOM_LIMIT))
- return;
- p = remove_vm_area((void *)(PAGE_MASK & (unsigned long __force)addr));
- if (unlikely(!p)) {
- pr_err("iounmap: bad address %p\n", addr);
- return;
- }
- kfree(p);
- }
- EXPORT_SYMBOL(__iounmap);