138 lines
		
	
	
		
			3.2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			138 lines
		
	
	
		
			3.2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * arch/sh/mm/ioremap.c
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|  *
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|  * (C) Copyright 1995 1996 Linus Torvalds
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|  * (C) Copyright 2005 - 2010  Paul Mundt
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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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|  * 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/slab.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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| /*
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|  * Remap an arbitrary physical address space into the kernel virtual
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|  * address space. Needed when the kernel wants to access high addresses
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|  * directly.
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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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| void __iomem * __ref
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| __ioremap_caller(phys_addr_t phys_addr, unsigned long size,
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| 		 pgprot_t pgprot, void *caller)
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| {
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| 	struct vm_struct *area;
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| 	unsigned long offset, last_addr, addr, orig_addr;
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| 	void __iomem *mapped;
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| 
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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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| 	/*
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| 	 * If we can't yet use the regular approach, go the fixmap route.
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| 	 */
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| 	if (!mem_init_done)
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| 		return ioremap_fixed(phys_addr, size, pgprot);
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| 
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| 	/*
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| 	 * First try to remap through the PMB.
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| 	 * PMB entries are all pre-faulted.
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| 	 */
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| 	mapped = pmb_remap_caller(phys_addr, size, pgprot, caller);
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| 	if (mapped && !IS_ERR(mapped))
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| 		return mapped;
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| 
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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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| 
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| 	/*
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| 	 * Ok, go for it..
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| 	 */
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| 	area = get_vm_area_caller(size, VM_IOREMAP, caller);
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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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| 	orig_addr = addr = (unsigned long)area->addr;
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| 
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| 	if (ioremap_page_range(addr, addr + size, phys_addr, pgprot)) {
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| 		vunmap((void *)orig_addr);
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| 		return NULL;
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| 	}
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| 
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| 	return (void __iomem *)(offset + (char *)orig_addr);
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| }
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| EXPORT_SYMBOL(__ioremap_caller);
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| 
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| /*
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|  * Simple checks for non-translatable mappings.
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|  */
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| static inline int iomapping_nontranslatable(unsigned long offset)
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| {
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| #ifdef CONFIG_29BIT
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| 	/*
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| 	 * In 29-bit mode this includes the fixed P1/P2 areas, as well as
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| 	 * parts of P3.
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| 	 */
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| 	if (PXSEG(offset) < P3SEG || offset >= P3_ADDR_MAX)
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| 		return 1;
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| #endif
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| 
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| 	return 0;
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| }
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| 
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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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| 	struct vm_struct *p;
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| 
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| 	/*
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| 	 * Nothing to do if there is no translatable mapping.
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| 	 */
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| 	if (iomapping_nontranslatable(vaddr))
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| 		return;
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| 
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| 	/*
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| 	 * There's no VMA if it's from an early fixed mapping.
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| 	 */
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| 	if (iounmap_fixed(addr) == 0)
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| 		return;
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| 
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| 	/*
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| 	 * If the PMB handled it, there's nothing else to do.
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| 	 */
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| 	if (pmb_unmap(addr) == 0)
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| 		return;
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| 
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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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| 
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| 	kfree(p);
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| }
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| EXPORT_SYMBOL(__iounmap);
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