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76d21d186a
Some user space drivers need accessing IO address and IO remap need SO(strong order) page-attribute to make IO operation correct. So we need add SO-page-attr for all non-memory address. Signed-off-by: Guo Ren <ren_guo@c-sky.com> Reported-by: Fan Xiaodong <xiaodong.fan@boyahualu.com>
62 lines
1.4 KiB
C
62 lines
1.4 KiB
C
// SPDX-License-Identifier: GPL-2.0
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// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
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#include <linux/export.h>
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#include <linux/mm.h>
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#include <linux/vmalloc.h>
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#include <linux/io.h>
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#include <asm/pgtable.h>
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void __iomem *ioremap(phys_addr_t addr, size_t size)
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{
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phys_addr_t last_addr;
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unsigned long offset, vaddr;
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struct vm_struct *area;
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pgprot_t prot;
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last_addr = addr + size - 1;
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if (!size || last_addr < addr)
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return NULL;
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offset = addr & (~PAGE_MASK);
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addr &= PAGE_MASK;
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size = PAGE_ALIGN(size + offset);
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area = get_vm_area_caller(size, VM_ALLOC, __builtin_return_address(0));
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if (!area)
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return NULL;
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vaddr = (unsigned long)area->addr;
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prot = __pgprot(_PAGE_PRESENT | __READABLE | __WRITEABLE |
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_PAGE_GLOBAL | _CACHE_UNCACHED | _PAGE_SO);
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if (ioremap_page_range(vaddr, vaddr + size, addr, prot)) {
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free_vm_area(area);
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return NULL;
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}
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return (void __iomem *)(vaddr + offset);
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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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vunmap((void *)((unsigned long)addr & PAGE_MASK));
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}
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EXPORT_SYMBOL(iounmap);
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pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
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unsigned long size, pgprot_t vma_prot)
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{
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if (!pfn_valid(pfn)) {
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vma_prot.pgprot |= _PAGE_SO;
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return pgprot_noncached(vma_prot);
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} else if (file->f_flags & O_SYNC) {
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return pgprot_noncached(vma_prot);
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}
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return vma_prot;
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}
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EXPORT_SYMBOL(phys_mem_access_prot);
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