forked from luck/tmp_suning_uos_patched
b15d53d009
kmap_coherent needs disabled preemption to not schedule in the critical
section, just like kmap_coherent on mips and kmap_atomic in general.
Fixes: 8222dbe21e "sched/preempt, mm/fault: Decouple preemption from the page fault logic"
Reported-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Tested-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Rich Felker <dalias@libc.org>
70 lines
1.7 KiB
C
70 lines
1.7 KiB
C
/*
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* arch/sh/mm/kmap.c
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*
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* Copyright (C) 1999, 2000, 2002 Niibe Yutaka
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* Copyright (C) 2002 - 2009 Paul Mundt
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*
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* Released under the terms of the GNU GPL v2.0.
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*/
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#include <linux/mm.h>
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#include <linux/init.h>
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#include <linux/mutex.h>
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#include <linux/fs.h>
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#include <linux/highmem.h>
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#include <linux/module.h>
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#include <asm/mmu_context.h>
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#include <asm/cacheflush.h>
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#define kmap_get_fixmap_pte(vaddr) \
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pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr), (vaddr)), (vaddr)), (vaddr))
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static pte_t *kmap_coherent_pte;
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void __init kmap_coherent_init(void)
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{
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unsigned long vaddr;
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/* cache the first coherent kmap pte */
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vaddr = __fix_to_virt(FIX_CMAP_BEGIN);
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kmap_coherent_pte = kmap_get_fixmap_pte(vaddr);
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}
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void *kmap_coherent(struct page *page, unsigned long addr)
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{
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enum fixed_addresses idx;
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unsigned long vaddr;
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BUG_ON(!test_bit(PG_dcache_clean, &page->flags));
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preempt_disable();
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pagefault_disable();
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idx = FIX_CMAP_END -
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(((addr >> PAGE_SHIFT) & (FIX_N_COLOURS - 1)) +
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(FIX_N_COLOURS * smp_processor_id()));
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vaddr = __fix_to_virt(idx);
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BUG_ON(!pte_none(*(kmap_coherent_pte - idx)));
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set_pte(kmap_coherent_pte - idx, mk_pte(page, PAGE_KERNEL));
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return (void *)vaddr;
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}
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void kunmap_coherent(void *kvaddr)
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{
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if (kvaddr >= (void *)FIXADDR_START) {
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unsigned long vaddr = (unsigned long)kvaddr & PAGE_MASK;
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enum fixed_addresses idx = __virt_to_fix(vaddr);
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/* XXX.. Kill this later, here for sanity at the moment.. */
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__flush_purge_region((void *)vaddr, PAGE_SIZE);
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pte_clear(&init_mm, vaddr, kmap_coherent_pte - idx);
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local_flush_tlb_one(get_asid(), vaddr);
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}
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pagefault_enable();
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preempt_enable();
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}
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