/* * arch/sh/mm/ioremap.c * * 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 * * (C) Copyright 1995 1996 Linus Torvalds * (C) Copyright 2005, 2006 Paul Mundt * * 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/mm.h> #include <linux/pci.h> #include <linux/io.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> /* * 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, unsigned long size, unsigned long flags) { struct vm_struct * area; unsigned long offset, last_addr, addr, orig_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; /* * If we're on an SH7751 or SH7780 PCI controller, PCI memory is * mapped at the end of the address space (typically 0xfd000000) * in a non-translatable area, so mapping through page tables for * this area is not only pointless, but also fundamentally * broken. Just return the physical address instead. * * For boards that map a small PCI memory aperture somewhere in * P1/P2 space, ioremap() will already do the right thing, * and we'll never get this far. */ if (is_pci_memaddr(phys_addr) && is_pci_memaddr(last_addr)) return (void __iomem *)phys_addr; /* * Don't allow anybody to remap normal RAM that we're using.. */ if (phys_addr < virt_to_phys(high_memory)) return NULL; /* * 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; orig_addr = addr = (unsigned long)area->addr; #ifdef CONFIG_32BIT /* * First try to remap through the PMB once a valid VMA has been * established. Smaller allocations (or the rest of the size * remaining after a PMB mapping due to the size not being * perfectly aligned on a PMB size boundary) are then mapped * through the UTLB using conventional page tables. * * PMB entries are all pre-faulted. */ if (unlikely(size >= 0x1000000)) { unsigned long mapped = pmb_remap(addr, phys_addr, size, flags); if (likely(mapped)) { addr += mapped; phys_addr += mapped; size -= mapped; } } #endif pgprot = __pgprot(pgprot_val(PAGE_KERNEL_NOCACHE) | flags); if (likely(size)) if (ioremap_page_range(addr, addr + size, phys_addr, pgprot)) { vunmap((void *)orig_addr); return NULL; } return (void __iomem *)(offset + (char *)orig_addr); } EXPORT_SYMBOL(__ioremap); void __iounmap(void __iomem *addr) { unsigned long vaddr = (unsigned long __force)addr; struct vm_struct *p; if (PXSEG(vaddr) < P3SEG || is_pci_memaddr(vaddr)) return; #ifdef CONFIG_32BIT /* * Purge any PMB entries that may have been established for this * mapping, then proceed with conventional VMA teardown. * * XXX: Note that due to the way that remove_vm_area() does * matching of the resultant VMA, we aren't able to fast-forward * the address past the PMB space until the end of the VMA where * the page tables reside. As such, unmap_vm_area() will be * forced to linearly scan over the area until it finds the page * tables where PTEs that need to be unmapped actually reside, * which is far from optimal. Perhaps we need to use a separate * VMA for the PMB mappings? * -- PFM. */ pmb_unmap(vaddr); #endif p = remove_vm_area((void *)(vaddr & PAGE_MASK)); if (!p) { printk(KERN_ERR "%s: bad address %p\n", __FUNCTION__, addr); return; } kfree(p); } EXPORT_SYMBOL(__iounmap);