106 lines
		
	
	
		
			3.2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			106 lines
		
	
	
		
			3.2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  *  PowerPC version
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|  *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
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|  *
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|  *  Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au)
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|  *  and Cort Dougan (PReP) (cort@cs.nmt.edu)
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|  *    Copyright (C) 1996 Paul Mackerras
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|  *
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|  *  Derived from "arch/i386/mm/init.c"
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|  *    Copyright (C) 1991, 1992, 1993, 1994  Linus Torvalds
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|  *
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|  *  Dave Engebretsen <engebret@us.ibm.com>
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|  *      Rework for PPC64 port.
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|  *
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|  *  This program is free software; you can redistribute it and/or
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|  *  modify it under the terms of the GNU General Public License
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|  *  as published by the Free Software Foundation; either version
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|  *  2 of the License, or (at your option) any later version.
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|  *
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|  */
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| 
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| #undef DEBUG
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| 
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| #include <linux/string.h>
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| #include <asm/pgalloc.h>
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| #include <asm/pgtable.h>
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| 
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| static void pgd_ctor(void *addr)
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| {
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| 	memset(addr, 0, PGD_TABLE_SIZE);
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| }
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| 
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| static void pud_ctor(void *addr)
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| {
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| 	memset(addr, 0, PUD_TABLE_SIZE);
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| }
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| 
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| static void pmd_ctor(void *addr)
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| {
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| 	memset(addr, 0, PMD_TABLE_SIZE);
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| }
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| 
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| struct kmem_cache *pgtable_cache[MAX_PGTABLE_INDEX_SIZE];
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| EXPORT_SYMBOL_GPL(pgtable_cache);	/* used by kvm_hv module */
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| 
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| /*
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|  * Create a kmem_cache() for pagetables.  This is not used for PTE
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|  * pages - they're linked to struct page, come from the normal free
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|  * pages pool and have a different entry size (see real_pte_t) to
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|  * everything else.  Caches created by this function are used for all
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|  * the higher level pagetables, and for hugepage pagetables.
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|  */
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| void pgtable_cache_add(unsigned shift, void (*ctor)(void *))
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| {
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| 	char *name;
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| 	unsigned long table_size = sizeof(void *) << shift;
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| 	unsigned long align = table_size;
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| 
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| 	/* When batching pgtable pointers for RCU freeing, we store
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| 	 * the index size in the low bits.  Table alignment must be
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| 	 * big enough to fit it.
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| 	 *
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| 	 * Likewise, hugeapge pagetable pointers contain a (different)
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| 	 * shift value in the low bits.  All tables must be aligned so
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| 	 * as to leave enough 0 bits in the address to contain it. */
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| 	unsigned long minalign = max(MAX_PGTABLE_INDEX_SIZE + 1,
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| 				     HUGEPD_SHIFT_MASK + 1);
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| 	struct kmem_cache *new;
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| 
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| 	/* It would be nice if this was a BUILD_BUG_ON(), but at the
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| 	 * moment, gcc doesn't seem to recognize is_power_of_2 as a
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| 	 * constant expression, so so much for that. */
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| 	BUG_ON(!is_power_of_2(minalign));
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| 	BUG_ON((shift < 1) || (shift > MAX_PGTABLE_INDEX_SIZE));
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| 
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| 	if (PGT_CACHE(shift))
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| 		return; /* Already have a cache of this size */
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| 
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| 	align = max_t(unsigned long, align, minalign);
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| 	name = kasprintf(GFP_KERNEL, "pgtable-2^%d", shift);
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| 	new = kmem_cache_create(name, table_size, align, 0, ctor);
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| 	if (!new)
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| 		panic("Could not allocate pgtable cache for order %d", shift);
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| 
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| 	kfree(name);
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| 	pgtable_cache[shift - 1] = new;
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| 
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| 	pr_debug("Allocated pgtable cache for order %d\n", shift);
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| }
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| EXPORT_SYMBOL_GPL(pgtable_cache_add);	/* used by kvm_hv module */
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| 
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| void pgtable_cache_init(void)
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| {
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| 	pgtable_cache_add(PGD_INDEX_SIZE, pgd_ctor);
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| 
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| 	if (PMD_CACHE_INDEX && !PGT_CACHE(PMD_CACHE_INDEX))
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| 		pgtable_cache_add(PMD_CACHE_INDEX, pmd_ctor);
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| 	/*
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| 	 * In all current configs, when the PUD index exists it's the
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| 	 * same size as either the pgd or pmd index except with THP enabled
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| 	 * on book3s 64
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| 	 */
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| 	if (PUD_CACHE_INDEX && !PGT_CACHE(PUD_CACHE_INDEX))
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| 		pgtable_cache_add(PUD_CACHE_INDEX, pud_ctor);
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| }
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