forked from Minki/linux
2bee1b5848
Implement primitives necessary for the 4th level folding, add walks of p4d level where appropriate, replace 5leve-fixup.h with pgtable-nop4d.h and drop usage of __ARCH_USE_5LEVEL_HACK. Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Signed-off-by: Paul Burton <paulburton@kernel.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: James Hogan <jhogan@kernel.org> Cc: linux-mips@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org Cc: Mike Rapoport <rppt@kernel.org>
211 lines
5.0 KiB
C
211 lines
5.0 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 <asm/cacheflush.h>
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#include <asm/io.h>
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#include <asm/tlbflush.h>
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static inline void remap_area_pte(pte_t * pte, unsigned long address,
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phys_addr_t size, phys_addr_t phys_addr, unsigned long flags)
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{
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phys_addr_t end;
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unsigned long pfn;
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pgprot_t pgprot = __pgprot(_PAGE_GLOBAL | _PAGE_PRESENT | __READABLE
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| __WRITEABLE | flags);
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address &= ~PMD_MASK;
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end = address + size;
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if (end > PMD_SIZE)
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end = PMD_SIZE;
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BUG_ON(address >= end);
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pfn = phys_addr >> PAGE_SHIFT;
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do {
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if (!pte_none(*pte)) {
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printk("remap_area_pte: page already exists\n");
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BUG();
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}
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set_pte(pte, pfn_pte(pfn, pgprot));
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address += PAGE_SIZE;
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pfn++;
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pte++;
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} while (address && (address < end));
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}
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static inline int remap_area_pmd(pmd_t * pmd, unsigned long address,
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phys_addr_t size, phys_addr_t phys_addr, unsigned long flags)
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{
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phys_addr_t end;
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address &= ~PGDIR_MASK;
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end = address + size;
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if (end > PGDIR_SIZE)
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end = PGDIR_SIZE;
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phys_addr -= address;
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BUG_ON(address >= end);
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do {
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pte_t * pte = pte_alloc_kernel(pmd, address);
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if (!pte)
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return -ENOMEM;
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remap_area_pte(pte, address, end - address, address + phys_addr, flags);
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address = (address + PMD_SIZE) & PMD_MASK;
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pmd++;
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} while (address && (address < end));
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return 0;
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}
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static int remap_area_pages(unsigned long address, phys_addr_t phys_addr,
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phys_addr_t size, unsigned long flags)
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{
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int error;
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pgd_t * dir;
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unsigned long end = address + size;
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phys_addr -= address;
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dir = pgd_offset(&init_mm, address);
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flush_cache_all();
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BUG_ON(address >= end);
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do {
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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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error = -ENOMEM;
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p4d = p4d_alloc(&init_mm, dir, address);
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if (!p4d)
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break;
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pud = pud_alloc(&init_mm, p4d, address);
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if (!pud)
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break;
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pmd = pmd_alloc(&init_mm, pud, address);
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if (!pmd)
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break;
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if (remap_area_pmd(pmd, address, end - address,
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phys_addr + address, flags))
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break;
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error = 0;
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address = (address + PGDIR_SIZE) & PGDIR_MASK;
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dir++;
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} while (address && (address < end));
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flush_tlb_all();
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return error;
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}
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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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* Generic mapping function (not visible outside):
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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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#define IS_LOW512(addr) (!((phys_addr_t)(addr) & (phys_addr_t) ~0x1fffffffULL))
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void __iomem * __ioremap(phys_addr_t phys_addr, phys_addr_t size, unsigned long flags)
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{
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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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void * 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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/*
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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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addr = area->addr;
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if (remap_area_pages((unsigned long) addr, phys_addr, size, flags)) {
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vunmap(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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#define IS_KSEG1(addr) (((unsigned long)(addr) & ~0x1fffffffUL) == CKSEG1)
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void __iounmap(const volatile void __iomem *addr)
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{
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struct vm_struct *p;
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if (IS_KSEG1(addr))
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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 (!p)
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printk(KERN_ERR "iounmap: bad address %p\n", addr);
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kfree(p);
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}
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EXPORT_SYMBOL(__ioremap);
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EXPORT_SYMBOL(__iounmap);
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