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264 lines
6.2 KiB
264 lines
6.2 KiB
/* |
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* This file contains the routines setting up the linux page tables. |
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* |
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* Copyright (C) 2008 Michal Simek |
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* Copyright (C) 2008 PetaLogix |
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* |
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* Copyright (C) 2007 Xilinx, Inc. All rights reserved. |
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* |
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* Derived from arch/ppc/mm/pgtable.c: |
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* -- paulus |
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* |
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* Derived from arch/ppc/mm/init.c: |
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* Copyright (C) 1995-1996 Gary Thomas ([email protected]) |
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* |
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* Modifications by Paul Mackerras (PowerMac) ([email protected]) |
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* and Cort Dougan (PReP) ([email protected]) |
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* Copyright (C) 1996 Paul Mackerras |
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* Amiga/APUS changes by Jesper Skov ([email protected]). |
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* |
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* Derived from "arch/i386/mm/init.c" |
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* Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds |
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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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*/ |
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#include <linux/export.h> |
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#include <linux/kernel.h> |
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#include <linux/types.h> |
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#include <linux/vmalloc.h> |
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#include <linux/init.h> |
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#include <linux/mm_types.h> |
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#include <linux/pgtable.h> |
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#include <asm/pgalloc.h> |
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#include <linux/io.h> |
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#include <asm/mmu.h> |
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#include <asm/sections.h> |
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#include <asm/fixmap.h> |
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unsigned long ioremap_base; |
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unsigned long ioremap_bot; |
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EXPORT_SYMBOL(ioremap_bot); |
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static void __iomem *__ioremap(phys_addr_t addr, unsigned long size, |
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unsigned long flags) |
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{ |
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unsigned long v, i; |
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phys_addr_t p; |
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int err; |
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/* |
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* Choose an address to map it to. |
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* Once the vmalloc system is running, we use it. |
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* Before then, we use space going down from ioremap_base |
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* (ioremap_bot records where we're up to). |
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*/ |
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p = addr & PAGE_MASK; |
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size = PAGE_ALIGN(addr + size) - p; |
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/* |
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* Don't allow anybody to remap normal RAM that we're using. |
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* mem_init() sets high_memory so only do the check after that. |
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* |
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* However, allow remap of rootfs: TBD |
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*/ |
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if (mem_init_done && |
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p >= memory_start && p < virt_to_phys(high_memory) && |
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!(p >= __virt_to_phys((phys_addr_t)__bss_stop) && |
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p < __virt_to_phys((phys_addr_t)__bss_stop))) { |
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pr_warn("__ioremap(): phys addr "PTE_FMT" is RAM lr %ps\n", |
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(unsigned long)p, __builtin_return_address(0)); |
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return NULL; |
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} |
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if (size == 0) |
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return NULL; |
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/* |
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* Is it already mapped? If the whole area is mapped then we're |
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* done, otherwise remap it since we want to keep the virt addrs for |
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* each request contiguous. |
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* |
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* We make the assumption here that if the bottom and top |
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* of the range we want are mapped then it's mapped to the |
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* same virt address (and this is contiguous). |
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* -- Cort |
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*/ |
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if (mem_init_done) { |
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struct vm_struct *area; |
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area = get_vm_area(size, VM_IOREMAP); |
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if (area == NULL) |
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return NULL; |
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v = (unsigned long) area->addr; |
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} else { |
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v = (ioremap_bot -= size); |
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} |
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if ((flags & _PAGE_PRESENT) == 0) |
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flags |= _PAGE_KERNEL; |
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if (flags & _PAGE_NO_CACHE) |
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flags |= _PAGE_GUARDED; |
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err = 0; |
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for (i = 0; i < size && err == 0; i += PAGE_SIZE) |
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err = map_page(v + i, p + i, flags); |
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if (err) { |
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if (mem_init_done) |
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vfree((void *)v); |
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return NULL; |
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} |
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return (void __iomem *) (v + ((unsigned long)addr & ~PAGE_MASK)); |
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} |
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void __iomem *ioremap(phys_addr_t addr, unsigned long size) |
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{ |
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return __ioremap(addr, size, _PAGE_NO_CACHE); |
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} |
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EXPORT_SYMBOL(ioremap); |
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void iounmap(volatile void __iomem *addr) |
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{ |
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if ((__force void *)addr > high_memory && |
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(unsigned long) addr < ioremap_bot) |
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vfree((void *) (PAGE_MASK & (unsigned long) addr)); |
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} |
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EXPORT_SYMBOL(iounmap); |
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int map_page(unsigned long va, phys_addr_t pa, int flags) |
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{ |
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p4d_t *p4d; |
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pud_t *pud; |
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pmd_t *pd; |
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pte_t *pg; |
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int err = -ENOMEM; |
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/* Use upper 10 bits of VA to index the first level map */ |
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p4d = p4d_offset(pgd_offset_k(va), va); |
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pud = pud_offset(p4d, va); |
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pd = pmd_offset(pud, va); |
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/* Use middle 10 bits of VA to index the second-level map */ |
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pg = pte_alloc_kernel(pd, va); /* from powerpc - pgtable.c */ |
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/* pg = pte_alloc_kernel(&init_mm, pd, va); */ |
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if (pg != NULL) { |
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err = 0; |
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set_pte_at(&init_mm, va, pg, pfn_pte(pa >> PAGE_SHIFT, |
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__pgprot(flags))); |
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if (unlikely(mem_init_done)) |
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_tlbie(va); |
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} |
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return err; |
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} |
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/* |
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* Map in all of physical memory starting at CONFIG_KERNEL_START. |
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*/ |
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void __init mapin_ram(void) |
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{ |
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unsigned long v, p, s, f; |
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v = CONFIG_KERNEL_START; |
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p = memory_start; |
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for (s = 0; s < lowmem_size; s += PAGE_SIZE) { |
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f = _PAGE_PRESENT | _PAGE_ACCESSED | |
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_PAGE_SHARED | _PAGE_HWEXEC; |
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if ((char *) v < _stext || (char *) v >= _etext) |
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f |= _PAGE_WRENABLE; |
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else |
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/* On the MicroBlaze, no user access |
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forces R/W kernel access */ |
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f |= _PAGE_USER; |
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map_page(v, p, f); |
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v += PAGE_SIZE; |
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p += PAGE_SIZE; |
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} |
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} |
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/* is x a power of 2? */ |
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#define is_power_of_2(x) ((x) != 0 && (((x) & ((x) - 1)) == 0)) |
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/* Scan the real Linux page tables and return a PTE pointer for |
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* a virtual address in a context. |
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* Returns true (1) if PTE was found, zero otherwise. The pointer to |
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* the PTE pointer is unmodified if PTE is not found. |
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*/ |
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static int get_pteptr(struct mm_struct *mm, unsigned long addr, pte_t **ptep) |
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{ |
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pgd_t *pgd; |
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p4d_t *p4d; |
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pud_t *pud; |
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pmd_t *pmd; |
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pte_t *pte; |
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int retval = 0; |
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pgd = pgd_offset(mm, addr & PAGE_MASK); |
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if (pgd) { |
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p4d = p4d_offset(pgd, addr & PAGE_MASK); |
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pud = pud_offset(p4d, addr & PAGE_MASK); |
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pmd = pmd_offset(pud, addr & PAGE_MASK); |
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if (pmd_present(*pmd)) { |
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pte = pte_offset_kernel(pmd, addr & PAGE_MASK); |
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if (pte) { |
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retval = 1; |
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*ptep = pte; |
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} |
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} |
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} |
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return retval; |
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} |
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/* Find physical address for this virtual address. Normally used by |
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* I/O functions, but anyone can call it. |
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*/ |
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unsigned long iopa(unsigned long addr) |
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{ |
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unsigned long pa; |
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pte_t *pte; |
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struct mm_struct *mm; |
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/* Allow mapping of user addresses (within the thread) |
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* for DMA if necessary. |
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*/ |
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if (addr < TASK_SIZE) |
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mm = current->mm; |
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else |
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mm = &init_mm; |
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pa = 0; |
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if (get_pteptr(mm, addr, &pte)) |
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pa = (pte_val(*pte) & PAGE_MASK) | (addr & ~PAGE_MASK); |
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return pa; |
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} |
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__ref pte_t *pte_alloc_one_kernel(struct mm_struct *mm) |
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{ |
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pte_t *pte; |
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if (mem_init_done) { |
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pte = (pte_t *)__get_free_page(GFP_KERNEL | __GFP_ZERO); |
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} else { |
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pte = (pte_t *)early_get_page(); |
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if (pte) |
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clear_page(pte); |
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} |
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return pte; |
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} |
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void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t flags) |
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{ |
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unsigned long address = __fix_to_virt(idx); |
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if (idx >= __end_of_fixed_addresses) |
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BUG(); |
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map_page(address, phys, pgprot_val(flags)); |
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}
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