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e540b8c5da
Recent commit a5f6164831 ("mm/ioremap: add slab availability checking in
ioremap_prot") added the slab availability check to the generic
ioremap_prot() implementation. It is reasonable to be done for the
MIPS32-specific method too since it also relies on the
get_vm_area_caller() function (by means of get_vm_area()) which requires
the slab allocator being up and running before being called.
Signed-off-by: Serge Semin <fancer.lancer@gmail.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
124 lines
3.2 KiB
C
124 lines
3.2 KiB
C
/*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file "COPYING" in the main directory of this archive
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* for more details.
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*
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* (C) Copyright 1995 1996 Linus Torvalds
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* (C) Copyright 2001, 2002 Ralf Baechle
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*/
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#include <linux/export.h>
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#include <asm/addrspace.h>
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#include <asm/byteorder.h>
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#include <linux/ioport.h>
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#include <linux/sched.h>
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#include <linux/slab.h>
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#include <linux/vmalloc.h>
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#include <linux/mm_types.h>
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#include <linux/io.h>
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#include <asm/cacheflush.h>
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#include <asm/tlbflush.h>
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#include <ioremap.h>
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#define IS_LOW512(addr) (!((phys_addr_t)(addr) & (phys_addr_t) ~0x1fffffffULL))
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#define IS_KSEG1(addr) (((unsigned long)(addr) & ~0x1fffffffUL) == CKSEG1)
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static int __ioremap_check_ram(unsigned long start_pfn, unsigned long nr_pages,
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void *arg)
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{
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unsigned long i;
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for (i = 0; i < nr_pages; i++) {
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if (pfn_valid(start_pfn + i) &&
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!PageReserved(pfn_to_page(start_pfn + i)))
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return 1;
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}
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return 0;
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}
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/*
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* ioremap_prot - map bus memory into CPU space
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* @phys_addr: bus address of the memory
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* @size: size of the resource to map
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*
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* ioremap_prot gives the caller control over cache coherency attributes (CCA)
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*/
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void __iomem *ioremap_prot(phys_addr_t phys_addr, unsigned long size,
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unsigned long prot_val)
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{
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unsigned long flags = prot_val & _CACHE_MASK;
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unsigned long offset, pfn, last_pfn;
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struct vm_struct *area;
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phys_addr_t last_addr;
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unsigned long vaddr;
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void __iomem *cpu_addr;
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cpu_addr = plat_ioremap(phys_addr, size, flags);
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if (cpu_addr)
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return cpu_addr;
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phys_addr = fixup_bigphys_addr(phys_addr, size);
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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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* Map uncached objects in the low 512mb of address space using KSEG1,
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* otherwise map using page tables.
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*/
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if (IS_LOW512(phys_addr) && IS_LOW512(last_addr) &&
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flags == _CACHE_UNCACHED)
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return (void __iomem *) CKSEG1ADDR(phys_addr);
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/* Early remaps should use the unmapped regions til' VM is available */
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if (WARN_ON_ONCE(!slab_is_available()))
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return NULL;
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/*
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* Don't allow anybody to remap RAM that may be allocated by the page
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* allocator, since that could lead to races & data clobbering.
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*/
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pfn = PFN_DOWN(phys_addr);
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last_pfn = PFN_DOWN(last_addr);
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if (walk_system_ram_range(pfn, last_pfn - pfn + 1, NULL,
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__ioremap_check_ram) == 1) {
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WARN_ONCE(1, "ioremap on RAM at %pa - %pa\n",
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&phys_addr, &last_addr);
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return NULL;
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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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* 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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vaddr = (unsigned long)area->addr;
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flags |= _PAGE_GLOBAL | _PAGE_PRESENT | __READABLE | __WRITEABLE;
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if (ioremap_page_range(vaddr, vaddr + size, phys_addr,
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__pgprot(flags))) {
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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_prot);
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void iounmap(const volatile void __iomem *addr)
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{
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if (!plat_iounmap(addr) && !IS_KSEG1(addr))
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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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