0906a3ad33
This fixes up the kmap_coherent/kunmap_coherent() interface for recent changes both in the page fault path and the shared cache flushers, as well as adding in some optimizations. One of the key things to note here is that the TLB flush itself is deferred until the unmap, and the call in to update_mmu_cache() itself goes away, relying on the regular page fault path to handle the lazy dcache writeback if necessary. Signed-off-by: Paul Mundt <lethal@linux-sh.org>
63 lines
1.5 KiB
C
63 lines
1.5 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_dirty, &page->flags));
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pagefault_disable();
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idx = FIX_CMAP_END -
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((addr & current_cpu_data.dcache.alias_mask) >> PAGE_SHIFT);
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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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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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}
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