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Diffstat (limited to 'arch/sh/mm/ioremap_32.c')
| -rw-r--r-- | arch/sh/mm/ioremap_32.c | 150 |
1 files changed, 150 insertions, 0 deletions
diff --git a/arch/sh/mm/ioremap_32.c b/arch/sh/mm/ioremap_32.c new file mode 100644 index 00000000000..0c7b7e33abd --- /dev/null +++ b/arch/sh/mm/ioremap_32.c @@ -0,0 +1,150 @@ +/* + * 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); |