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https://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson
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27ac792ca0
On 32-bit architectures PAGE_ALIGN() truncates 64-bit values to the 32-bit boundary. For example: u64 val = PAGE_ALIGN(size); always returns a value < 4GB even if size is greater than 4GB. The problem resides in PAGE_MASK definition (from include/asm-x86/page.h for example): #define PAGE_SHIFT 12 #define PAGE_SIZE (_AC(1,UL) << PAGE_SHIFT) #define PAGE_MASK (~(PAGE_SIZE-1)) ... #define PAGE_ALIGN(addr) (((addr)+PAGE_SIZE-1)&PAGE_MASK) The "~" is performed on a 32-bit value, so everything in "and" with PAGE_MASK greater than 4GB will be truncated to the 32-bit boundary. Using the ALIGN() macro seems to be the right way, because it uses typeof(addr) for the mask. Also move the PAGE_ALIGN() definitions out of include/asm-*/page.h in include/linux/mm.h. See also lkml discussion: http://lkml.org/lkml/2008/6/11/237 [akpm@linux-foundation.org: fix drivers/media/video/uvc/uvc_queue.c] [akpm@linux-foundation.org: fix v850] [akpm@linux-foundation.org: fix powerpc] [akpm@linux-foundation.org: fix arm] [akpm@linux-foundation.org: fix mips] [akpm@linux-foundation.org: fix drivers/media/video/pvrusb2/pvrusb2-dvb.c] [akpm@linux-foundation.org: fix drivers/mtd/maps/uclinux.c] [akpm@linux-foundation.org: fix powerpc] Signed-off-by: Andrea Righi <righi.andrea@gmail.com> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
93 lines
2.3 KiB
C
93 lines
2.3 KiB
C
/*
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* Copyright (C) 2004-2006 Atmel Corporation
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/vmalloc.h>
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#include <linux/mm.h>
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#include <linux/module.h>
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#include <linux/io.h>
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#include <asm/pgtable.h>
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#include <asm/addrspace.h>
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/*
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* Re-map an arbitrary physical address space into the kernel virtual
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* address space. Needed when the kernel wants to access physical
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* memory directly.
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*/
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void __iomem *__ioremap(unsigned long phys_addr, size_t size,
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unsigned long flags)
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{
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unsigned long addr;
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struct vm_struct *area;
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unsigned long offset, last_addr;
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pgprot_t prot;
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/*
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* Check if we can simply use the P4 segment. This area is
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* uncacheable, so if caching/buffering is requested, we can't
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* use it.
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*/
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if ((phys_addr >= P4SEG) && (flags == 0))
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return (void __iomem *)phys_addr;
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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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* XXX: When mapping regular RAM, we'd better make damn sure
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* it's never used for anything else. But this is really the
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* caller's responsibility...
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*/
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if (PHYSADDR(P2SEGADDR(phys_addr)) == phys_addr)
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return (void __iomem *)P2SEGADDR(phys_addr);
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/* Mappings have to be page-aligned */
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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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prot = __pgprot(_PAGE_PRESENT | _PAGE_GLOBAL | _PAGE_RW | _PAGE_DIRTY
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| _PAGE_ACCESSED | _PAGE_TYPE_SMALL | flags);
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/*
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* Ok, go for it..
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*/
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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, prot)) {
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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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EXPORT_SYMBOL(__ioremap);
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void __iounmap(void __iomem *addr)
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{
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struct vm_struct *p;
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if ((unsigned long)addr >= P4SEG)
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return;
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if (PXSEG(addr) == P2SEG)
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return;
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p = remove_vm_area((void *)(PAGE_MASK & (unsigned long __force)addr));
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if (unlikely(!p)) {
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printk (KERN_ERR "iounmap: bad address %p\n", 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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