/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _LINUX_SLAB_DEF_H
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#define _LINUX_SLAB_DEF_H
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#include <linux/kfence.h>
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#include <linux/reciprocal_div.h>
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/*
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* Definitions unique to the original Linux SLAB allocator.
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*/
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struct kmem_cache {
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struct array_cache __percpu *cpu_cache;
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/* 1) Cache tunables. Protected by slab_mutex */
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unsigned int batchcount;
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unsigned int limit;
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unsigned int shared;
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unsigned int size;
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struct reciprocal_value reciprocal_buffer_size;
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/* 2) touched by every alloc & free from the backend */
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slab_flags_t flags; /* constant flags */
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unsigned int num; /* # of objs per slab */
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/* 3) cache_grow/shrink */
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/* order of pgs per slab (2^n) */
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unsigned int gfporder;
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/* force GFP flags, e.g. GFP_DMA */
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gfp_t allocflags;
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size_t colour; /* cache colouring range */
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unsigned int colour_off; /* colour offset */
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struct kmem_cache *freelist_cache;
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unsigned int freelist_size;
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/* constructor func */
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void (*ctor)(void *obj);
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/* 4) cache creation/removal */
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const char *name;
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struct list_head list;
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int refcount;
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int object_size;
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int align;
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/* 5) statistics */
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#ifdef CONFIG_DEBUG_SLAB
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unsigned long num_active;
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unsigned long num_allocations;
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unsigned long high_mark;
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unsigned long grown;
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unsigned long reaped;
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unsigned long errors;
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unsigned long max_freeable;
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unsigned long node_allocs;
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unsigned long node_frees;
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unsigned long node_overflow;
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atomic_t allochit;
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atomic_t allocmiss;
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atomic_t freehit;
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atomic_t freemiss;
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/*
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* If debugging is enabled, then the allocator can add additional
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* fields and/or padding to every object. 'size' contains the total
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* object size including these internal fields, while 'obj_offset'
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* and 'object_size' contain the offset to the user object and its
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* size.
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*/
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int obj_offset;
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#endif /* CONFIG_DEBUG_SLAB */
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#ifdef CONFIG_KASAN
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struct kasan_cache kasan_info;
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#endif
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#ifdef CONFIG_SLAB_FREELIST_RANDOM
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unsigned int *random_seq;
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#endif
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unsigned int useroffset; /* Usercopy region offset */
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unsigned int usersize; /* Usercopy region size */
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struct kmem_cache_node *node[MAX_NUMNODES];
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};
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static inline void *nearest_obj(struct kmem_cache *cache, struct page *page,
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void *x)
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{
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void *object = x - (x - page->s_mem) % cache->size;
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void *last_object = page->s_mem + (cache->num - 1) * cache->size;
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if (unlikely(object > last_object))
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return last_object;
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else
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return object;
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}
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/*
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* We want to avoid an expensive divide : (offset / cache->size)
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* Using the fact that size is a constant for a particular cache,
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* we can replace (offset / cache->size) by
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* reciprocal_divide(offset, cache->reciprocal_buffer_size)
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*/
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static inline unsigned int obj_to_index(const struct kmem_cache *cache,
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const struct page *page, void *obj)
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{
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u32 offset = (obj - page->s_mem);
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return reciprocal_divide(offset, cache->reciprocal_buffer_size);
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}
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static inline int objs_per_slab_page(const struct kmem_cache *cache,
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const struct page *page)
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{
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if (is_kfence_address(page_address(page)))
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return 1;
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return cache->num;
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}
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#endif /* _LINUX_SLAB_DEF_H */
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