149 lines
3.8 KiB
C
149 lines
3.8 KiB
C
/*
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* arch/sh/mm/ioremap.c
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*
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* Re-map IO memory to kernel address space so that we can access it.
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* This is needed for high PCI addresses that aren't mapped in the
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* 640k-1MB IO memory area on PC's
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*
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* (C) Copyright 1995 1996 Linus Torvalds
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* (C) Copyright 2005, 2006 Paul Mundt
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*
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* This file is subject to the terms and conditions of the GNU General
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* Public License. See the file "COPYING" in the main directory of this
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* archive for more details.
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*/
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#include <linux/vmalloc.h>
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#include <linux/module.h>
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#include <linux/mm.h>
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#include <linux/pci.h>
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#include <linux/io.h>
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#include <asm/page.h>
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#include <asm/pgalloc.h>
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#include <asm/addrspace.h>
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#include <asm/cacheflush.h>
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#include <asm/tlbflush.h>
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#include <asm/mmu.h>
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/*
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* Remap an arbitrary physical address space into the kernel virtual
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* address space.
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*
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* NOTE! We need to allow non-page-aligned mappings too: we will obviously
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* have to convert them into an offset in a page-aligned mapping, but the
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* caller shouldn't need to know that small detail.
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*/
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static void __iomem *__ioremap_prot(unsigned long phys_addr, unsigned long size,
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pgprot_t pgprot)
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{
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struct vm_struct * area;
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unsigned long offset, last_addr, addr;
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int simple = (pgprot_val(pgprot) == pgprot_val(PAGE_KERNEL)) ||
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(pgprot_val(pgprot) == pgprot_val(PAGE_KERNEL_NOCACHE));
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int cached = pgprot_val(pgprot) & _PAGE_CACHABLE;
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/* Don't allow wraparound or zero size */
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last_addr = phys_addr + size - 1;
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if (!size || last_addr < phys_addr)
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return NULL;
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/*
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* If we're in the fixed PCI memory range, mapping through page
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* tables is not only pointless, but also fundamentally broken.
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* Just return the physical address instead.
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*
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* For boards that map a small PCI memory aperture somewhere in
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* P1/P2 space, ioremap() will already do the right thing,
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* and we'll never get this far.
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*/
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if (is_pci_memory_fixed_range(phys_addr, size))
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return (void __iomem *)phys_addr;
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/*
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* Don't allow anybody to remap normal RAM that we're using..
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*/
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if ((phys_addr >= __pa(memory_start)) && (last_addr < __pa(memory_end))) {
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char *t_addr, *t_end;
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struct page *page;
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t_addr = __va(phys_addr);
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t_end = t_addr + (size - 1);
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for(page = virt_to_page(t_addr); page <= virt_to_page(t_end); page++)
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if(!PageReserved(page))
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return NULL;
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}
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/* P4 uncached addresses are permanently mapped */
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if ((PXSEG(phys_addr) == P4SEG) && simple && !cached)
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return (void __iomem *)phys_addr;
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/*
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* Mappings have to be page-aligned
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*/
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offset = phys_addr & ~PAGE_MASK;
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phys_addr &= PAGE_MASK;
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size = PAGE_ALIGN(last_addr+1) - phys_addr;
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#ifdef CONFIG_PMB
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addr = pmb_remap(phys_addr, size, cached ? _PAGE_CACHABLE : 0);
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if (addr)
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return (void __iomem *)(offset + (char *)addr);
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#endif
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area = get_vm_area(size, VM_IOREMAP);
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if (!area)
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return NULL;
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area->phys_addr = phys_addr;
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addr = (unsigned long)area->addr;
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if (ioremap_page_range(addr, addr + size, phys_addr, pgprot)) {
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vunmap((void *)addr);
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return NULL;
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}
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return (void __iomem *)(offset + (char *)addr);
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}
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void __iomem *__ioremap(unsigned long phys_addr, unsigned long size,
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unsigned long flags)
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{
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pgprot_t pgprot;
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if (unlikely(flags & _PAGE_CACHABLE))
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pgprot = PAGE_KERNEL;
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else
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pgprot = PAGE_KERNEL_NOCACHE;
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return __ioremap_prot(phys_addr, size, pgprot);
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}
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EXPORT_SYMBOL(__ioremap);
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void __iounmap(void __iomem *addr)
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{
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unsigned long vaddr = (unsigned long __force)addr;
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unsigned long seg = PXSEG(vaddr);
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struct vm_struct *p;
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if (seg == P4SEG || is_pci_memory_fixed_range(vaddr, 0))
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return;
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#ifdef CONFIG_29BIT
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if (seg < P3SEG)
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return;
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#endif
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#ifdef CONFIG_PMB
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if (pmb_unmap(vaddr))
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return;
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#endif
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p = remove_vm_area((void *)(vaddr & PAGE_MASK));
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if (!p) {
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printk(KERN_ERR "%s: bad address %p\n", __func__, addr);
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return;
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}
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kfree(p);
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}
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EXPORT_SYMBOL(__iounmap);
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