This follows the ARM change c01778001a
("ARM: 6379/1: Assume new page cache pages have dirty D-cache") for the
same rationale:
    There are places in Linux where writes to newly allocated page
    cache pages happen without a subsequent call to flush_dcache_page()
    (several PIO drivers including USB HCD). This patch changes the
    meaning of PG_arch_1 to be PG_dcache_clean and always flush the
    D-cache for a newly mapped page in update_mmu_cache().
This addresses issues seen with executing binaries from MMC, in
addition to some of the other HCDs that don't explicitly do cache
management for their pipe-in buffers.
Requested-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
		
	
			
		
			
				
	
	
		
			67 lines
		
	
	
	
		
			1.6 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			67 lines
		
	
	
	
		
			1.6 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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	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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}
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