90e7d649d8
This implements a fairly significant overhaul of the dynamic PMB mapping code. The primary change here is that the PMB gets its own VMA that follows the uncached mapping and we attempt to be a bit more intelligent with dynamic sizing, multi-entry mapping, and so forth. Signed-off-by: Paul Mundt <lethal@linux-sh.org>
137 lines
3.2 KiB
C
137 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/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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* 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 * __init_refok
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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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/* 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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* 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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* 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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* 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_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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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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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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* 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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return 0;
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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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* 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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* 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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* 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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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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kfree(p);
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}
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EXPORT_SYMBOL(__iounmap);
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