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f3b17320db
Openrisc is the only architecture not mapping ioremap as uncached, which has been the default since the Linux 2.6.x days. Switch it over to implement uncached semantics by default. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Stafford Horne <shorne@gmail.com>
131 lines
3.6 KiB
C
131 lines
3.6 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* OpenRISC ioremap.c
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*
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* Linux architectural port borrowing liberally from similar works of
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* others. All original copyrights apply as per the original source
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* declaration.
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*
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* Modifications for the OpenRISC architecture:
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* Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>
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* Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
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*/
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#include <linux/vmalloc.h>
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#include <linux/io.h>
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#include <asm/pgalloc.h>
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#include <asm/kmap_types.h>
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#include <asm/fixmap.h>
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#include <asm/bug.h>
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#include <asm/pgtable.h>
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#include <linux/sched.h>
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#include <asm/tlbflush.h>
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extern int mem_init_done;
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static unsigned int fixmaps_used __initdata;
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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 *__ref ioremap(phys_addr_t addr, unsigned long size)
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{
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phys_addr_t p;
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unsigned long v;
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unsigned long offset, last_addr;
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struct vm_struct *area = NULL;
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/* Don't allow wraparound or zero size */
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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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/*
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* Mappings have to be page-aligned
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*/
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offset = addr & ~PAGE_MASK;
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p = addr & PAGE_MASK;
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size = PAGE_ALIGN(last_addr + 1) - p;
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if (likely(mem_init_done)) {
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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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v = (unsigned long)area->addr;
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} else {
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if ((fixmaps_used + (size >> PAGE_SHIFT)) > FIX_N_IOREMAPS)
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return NULL;
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v = fix_to_virt(FIX_IOREMAP_BEGIN + fixmaps_used);
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fixmaps_used += (size >> PAGE_SHIFT);
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}
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if (ioremap_page_range(v, v + size, p,
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__pgprot(pgprot_val(PAGE_KERNEL) | _PAGE_CI))) {
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if (likely(mem_init_done))
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vfree(area->addr);
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else
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fixmaps_used -= (size >> PAGE_SHIFT);
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return NULL;
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}
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return (void __iomem *)(offset + (char *)v);
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}
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EXPORT_SYMBOL(ioremap);
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void iounmap(void *addr)
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{
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/* If the page is from the fixmap pool then we just clear out
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* the fixmap mapping.
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*/
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if (unlikely((unsigned long)addr > FIXADDR_START)) {
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/* This is a bit broken... we don't really know
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* how big the area is so it's difficult to know
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* how many fixed pages to invalidate...
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* just flush tlb and hope for the best...
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* consider this a FIXME
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*
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* Really we should be clearing out one or more page
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* table entries for these virtual addresses so that
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* future references cause a page fault... for now, we
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* rely on two things:
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* i) this code never gets called on known boards
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* ii) invalid accesses to the freed areas aren't made
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*/
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flush_tlb_all();
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return;
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}
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return vfree((void *)(PAGE_MASK & (unsigned long)addr));
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}
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EXPORT_SYMBOL(iounmap);
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/**
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* OK, this one's a bit tricky... ioremap can get called before memory is
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* initialized (early serial console does this) and will want to alloc a page
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* for its mapping. No userspace pages will ever get allocated before memory
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* is initialized so this applies only to kernel pages. In the event that
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* this is called before memory is initialized we allocate the page using
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* the memblock infrastructure.
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*/
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pte_t __ref *pte_alloc_one_kernel(struct mm_struct *mm)
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{
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pte_t *pte;
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if (likely(mem_init_done)) {
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pte = (pte_t *)get_zeroed_page(GFP_KERNEL);
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} else {
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pte = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
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if (!pte)
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panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
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__func__, PAGE_SIZE, PAGE_SIZE);
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}
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return pte;
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}
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