--- /dev/null
+/*
+ * Written by Mark Hemment, 1996 (markhe@nextd.demon.co.uk).
+ *
+ * (C) SGI 2006, Christoph Lameter
+ * Cleaned up and restructured to ease the addition of alternative
+ * implementations of SLAB allocators.
+ * (C) Linux Foundation 2008-2013
+ * Unified interface for all slab allocators
+ */
+
+#ifndef _LINUX_SLAB_H
+#define _LINUX_SLAB_H
+
+#include <linux/gfp.h>
+#include <linux/types.h>
+#include <linux/workqueue.h>
+
+
+/*
+ * Flags to pass to kmem_cache_create().
+ * The ones marked DEBUG are only valid if CONFIG_DEBUG_SLAB is set.
+ */
+#define SLAB_DEBUG_FREE 0x00000100UL /* DEBUG: Perform (expensive) checks on free */
+#define SLAB_RED_ZONE 0x00000400UL /* DEBUG: Red zone objs in a cache */
+#define SLAB_POISON 0x00000800UL /* DEBUG: Poison objects */
+#define SLAB_HWCACHE_ALIGN 0x00002000UL /* Align objs on cache lines */
+#define SLAB_CACHE_DMA 0x00004000UL /* Use GFP_DMA memory */
+#define SLAB_STORE_USER 0x00010000UL /* DEBUG: Store the last owner for bug hunting */
+#define SLAB_PANIC 0x00040000UL /* Panic if kmem_cache_create() fails */
+/*
+ * SLAB_DESTROY_BY_RCU - **WARNING** READ THIS!
+ *
+ * This delays freeing the SLAB page by a grace period, it does _NOT_
+ * delay object freeing. This means that if you do kmem_cache_free()
+ * that memory location is free to be reused at any time. Thus it may
+ * be possible to see another object there in the same RCU grace period.
+ *
+ * This feature only ensures the memory location backing the object
+ * stays valid, the trick to using this is relying on an independent
+ * object validation pass. Something like:
+ *
+ * rcu_read_lock()
+ * again:
+ * obj = lockless_lookup(key);
+ * if (obj) {
+ * if (!try_get_ref(obj)) // might fail for free objects
+ * goto again;
+ *
+ * if (obj->key != key) { // not the object we expected
+ * put_ref(obj);
+ * goto again;
+ * }
+ * }
+ * rcu_read_unlock();
+ *
+ * This is useful if we need to approach a kernel structure obliquely,
+ * from its address obtained without the usual locking. We can lock
+ * the structure to stabilize it and check it's still at the given address,
+ * only if we can be sure that the memory has not been meanwhile reused
+ * for some other kind of object (which our subsystem's lock might corrupt).
+ *
+ * rcu_read_lock before reading the address, then rcu_read_unlock after
+ * taking the spinlock within the structure expected at that address.
+ */
+#define SLAB_DESTROY_BY_RCU 0x00080000UL /* Defer freeing slabs to RCU */
+#define SLAB_MEM_SPREAD 0x00100000UL /* Spread some memory over cpuset */
+#define SLAB_TRACE 0x00200000UL /* Trace allocations and frees */
+
+/* Flag to prevent checks on free */
+#ifdef CONFIG_DEBUG_OBJECTS
+# define SLAB_DEBUG_OBJECTS 0x00400000UL
+#else
+# define SLAB_DEBUG_OBJECTS 0x00000000UL
+#endif
+
+#define SLAB_NOLEAKTRACE 0x00800000UL /* Avoid kmemleak tracing */
+
+/* Don't track use of uninitialized memory */
+#ifdef CONFIG_KMEMCHECK
+# define SLAB_NOTRACK 0x01000000UL
+#else
+# define SLAB_NOTRACK 0x00000000UL
+#endif
+#ifdef CONFIG_FAILSLAB
+# define SLAB_FAILSLAB 0x02000000UL /* Fault injection mark */
+#else
+# define SLAB_FAILSLAB 0x00000000UL
+#endif
+
+/* The following flags affect the page allocator grouping pages by mobility */
+#define SLAB_RECLAIM_ACCOUNT 0x00020000UL /* Objects are reclaimable */
+#define SLAB_TEMPORARY SLAB_RECLAIM_ACCOUNT /* Objects are short-lived */
+/*
+ * ZERO_SIZE_PTR will be returned for zero sized kmalloc requests.
+ *
+ * Dereferencing ZERO_SIZE_PTR will lead to a distinct access fault.
+ *
+ * ZERO_SIZE_PTR can be passed to kfree though in the same way that NULL can.
+ * Both make kfree a no-op.
+ */
+#define ZERO_SIZE_PTR ((void *)16)
+
+#define ZERO_OR_NULL_PTR(x) ((unsigned long)(x) <= \
+ (unsigned long)ZERO_SIZE_PTR)
+
+#include <linux/kmemleak.h>
+#include <linux/kasan.h>
+
+struct mem_cgroup;
+/*
+ * struct kmem_cache related prototypes
+ */
+void __init kmem_cache_init(void);
+int slab_is_available(void);
+
+struct kmem_cache *kmem_cache_create(const char *, size_t, size_t,
+ unsigned long,
+ void (*)(void *));
+void kmem_cache_destroy(struct kmem_cache *);
+int kmem_cache_shrink(struct kmem_cache *);
+
+void memcg_create_kmem_cache(struct mem_cgroup *, struct kmem_cache *);
+void memcg_deactivate_kmem_caches(struct mem_cgroup *);
+void memcg_destroy_kmem_caches(struct mem_cgroup *);
+
+/*
+ * Please use this macro to create slab caches. Simply specify the
+ * name of the structure and maybe some flags that are listed above.
+ *
+ * The alignment of the struct determines object alignment. If you
+ * f.e. add ____cacheline_aligned_in_smp to the struct declaration
+ * then the objects will be properly aligned in SMP configurations.
+ */
+#define KMEM_CACHE(__struct, __flags) kmem_cache_create(#__struct,\
+ sizeof(struct __struct), __alignof__(struct __struct),\
+ (__flags), NULL)
+
+/*
+ * Common kmalloc functions provided by all allocators
+ */
+void * __must_check __krealloc(const void *, size_t, gfp_t);
+void * __must_check krealloc(const void *, size_t, gfp_t);
+void kfree(const void *);
+void kzfree(const void *);
+size_t ksize(const void *);
+
+/*
+ * Some archs want to perform DMA into kmalloc caches and need a guaranteed
+ * alignment larger than the alignment of a 64-bit integer.
+ * Setting ARCH_KMALLOC_MINALIGN in arch headers allows that.
+ */
+#if defined(ARCH_DMA_MINALIGN) && ARCH_DMA_MINALIGN > 8
+#define ARCH_KMALLOC_MINALIGN ARCH_DMA_MINALIGN
+#define KMALLOC_MIN_SIZE ARCH_DMA_MINALIGN
+#define KMALLOC_SHIFT_LOW ilog2(ARCH_DMA_MINALIGN)
+#else
+#define ARCH_KMALLOC_MINALIGN __alignof__(unsigned long long)
+#endif
+
+/*
+ * Kmalloc array related definitions
+ */
+
+#ifdef CONFIG_SLAB
+/*
+ * The largest kmalloc size supported by the SLAB allocators is
+ * 32 megabyte (2^25) or the maximum allocatable page order if that is
+ * less than 32 MB.
+ *
+ * WARNING: Its not easy to increase this value since the allocators have
+ * to do various tricks to work around compiler limitations in order to
+ * ensure proper constant folding.
+ */
+#define KMALLOC_SHIFT_HIGH ((MAX_ORDER + PAGE_SHIFT - 1) <= 25 ? \
+ (MAX_ORDER + PAGE_SHIFT - 1) : 25)
+#define KMALLOC_SHIFT_MAX KMALLOC_SHIFT_HIGH
+#ifndef KMALLOC_SHIFT_LOW
+#define KMALLOC_SHIFT_LOW 5
+#endif
+#endif
+
+#ifdef CONFIG_SLUB
+/*
+ * SLUB directly allocates requests fitting in to an order-1 page
+ * (PAGE_SIZE*2). Larger requests are passed to the page allocator.
+ */
+#define KMALLOC_SHIFT_HIGH (PAGE_SHIFT + 1)
+#define KMALLOC_SHIFT_MAX (MAX_ORDER + PAGE_SHIFT)
+#ifndef KMALLOC_SHIFT_LOW
+#define KMALLOC_SHIFT_LOW 3
+#endif
+#endif
+
+#ifdef CONFIG_SLOB
+/*
+ * SLOB passes all requests larger than one page to the page allocator.
+ * No kmalloc array is necessary since objects of different sizes can
+ * be allocated from the same page.
+ */
+#define KMALLOC_SHIFT_HIGH PAGE_SHIFT
+#define KMALLOC_SHIFT_MAX 30
+#ifndef KMALLOC_SHIFT_LOW
+#define KMALLOC_SHIFT_LOW 3
+#endif
+#endif
+
+/* Maximum allocatable size */
+#define KMALLOC_MAX_SIZE (1UL << KMALLOC_SHIFT_MAX)
+/* Maximum size for which we actually use a slab cache */
+#define KMALLOC_MAX_CACHE_SIZE (1UL << KMALLOC_SHIFT_HIGH)
+/* Maximum order allocatable via the slab allocagtor */
+#define KMALLOC_MAX_ORDER (KMALLOC_SHIFT_MAX - PAGE_SHIFT)
+
+/*
+ * Kmalloc subsystem.
+ */
+#ifndef KMALLOC_MIN_SIZE
+#define KMALLOC_MIN_SIZE (1 << KMALLOC_SHIFT_LOW)
+#endif
+
+/*
+ * This restriction comes from byte sized index implementation.
+ * Page size is normally 2^12 bytes and, in this case, if we want to use
+ * byte sized index which can represent 2^8 entries, the size of the object
+ * should be equal or greater to 2^12 / 2^8 = 2^4 = 16.
+ * If minimum size of kmalloc is less than 16, we use it as minimum object
+ * size and give up to use byte sized index.
+ */
+#define SLAB_OBJ_MIN_SIZE (KMALLOC_MIN_SIZE < 16 ? \
+ (KMALLOC_MIN_SIZE) : 16)
+
+#ifndef CONFIG_SLOB
+extern struct kmem_cache *kmalloc_caches[KMALLOC_SHIFT_HIGH + 1];
+#ifdef CONFIG_ZONE_DMA
+extern struct kmem_cache *kmalloc_dma_caches[KMALLOC_SHIFT_HIGH + 1];
+#endif
+
+/*
+ * Figure out which kmalloc slab an allocation of a certain size
+ * belongs to.
+ * 0 = zero alloc
+ * 1 = 65 .. 96 bytes
+ * 2 = 120 .. 192 bytes
+ * n = 2^(n-1) .. 2^n -1
+ */
+static __always_inline int kmalloc_index(size_t size)
+{
+ if (!size)
+ return 0;
+
+ if (size <= KMALLOC_MIN_SIZE)
+ return KMALLOC_SHIFT_LOW;
+
+ if (KMALLOC_MIN_SIZE <= 32 && size > 64 && size <= 96)
+ return 1;
+ if (KMALLOC_MIN_SIZE <= 64 && size > 128 && size <= 192)
+ return 2;
+ if (size <= 8) return 3;
+ if (size <= 16) return 4;
+ if (size <= 32) return 5;
+ if (size <= 64) return 6;
+ if (size <= 128) return 7;
+ if (size <= 256) return 8;
+ if (size <= 512) return 9;
+ if (size <= 1024) return 10;
+ if (size <= 2 * 1024) return 11;
+ if (size <= 4 * 1024) return 12;
+ if (size <= 8 * 1024) return 13;
+ if (size <= 16 * 1024) return 14;
+ if (size <= 32 * 1024) return 15;
+ if (size <= 64 * 1024) return 16;
+ if (size <= 128 * 1024) return 17;
+ if (size <= 256 * 1024) return 18;
+ if (size <= 512 * 1024) return 19;
+ if (size <= 1024 * 1024) return 20;
+ if (size <= 2 * 1024 * 1024) return 21;
+ if (size <= 4 * 1024 * 1024) return 22;
+ if (size <= 8 * 1024 * 1024) return 23;
+ if (size <= 16 * 1024 * 1024) return 24;
+ if (size <= 32 * 1024 * 1024) return 25;
+ if (size <= 64 * 1024 * 1024) return 26;
+ BUG();
+
+ /* Will never be reached. Needed because the compiler may complain */
+ return -1;
+}
+#endif /* !CONFIG_SLOB */
+
+void *__kmalloc(size_t size, gfp_t flags);
+void *kmem_cache_alloc(struct kmem_cache *, gfp_t flags);
+void kmem_cache_free(struct kmem_cache *, void *);
+
+#ifdef CONFIG_NUMA
+void *__kmalloc_node(size_t size, gfp_t flags, int node);
+void *kmem_cache_alloc_node(struct kmem_cache *, gfp_t flags, int node);
+#else
+static __always_inline void *__kmalloc_node(size_t size, gfp_t flags, int node)
+{
+ return __kmalloc(size, flags);
+}
+
+static __always_inline void *kmem_cache_alloc_node(struct kmem_cache *s, gfp_t flags, int node)
+{
+ return kmem_cache_alloc(s, flags);
+}
+#endif
+
+#ifdef CONFIG_TRACING
+extern void *kmem_cache_alloc_trace(struct kmem_cache *, gfp_t, size_t);
+
+#ifdef CONFIG_NUMA
+extern void *kmem_cache_alloc_node_trace(struct kmem_cache *s,
+ gfp_t gfpflags,
+ int node, size_t size);
+#else
+static __always_inline void *
+kmem_cache_alloc_node_trace(struct kmem_cache *s,
+ gfp_t gfpflags,
+ int node, size_t size)
+{
+ return kmem_cache_alloc_trace(s, gfpflags, size);
+}
+#endif /* CONFIG_NUMA */
+
+#else /* CONFIG_TRACING */
+static __always_inline void *kmem_cache_alloc_trace(struct kmem_cache *s,
+ gfp_t flags, size_t size)
+{
+ void *ret = kmem_cache_alloc(s, flags);
+
+ kasan_kmalloc(s, ret, size);
+ return ret;
+}
+
+static __always_inline void *
+kmem_cache_alloc_node_trace(struct kmem_cache *s,
+ gfp_t gfpflags,
+ int node, size_t size)
+{
+ void *ret = kmem_cache_alloc_node(s, gfpflags, node);
+
+ kasan_kmalloc(s, ret, size);
+ return ret;
+}
+#endif /* CONFIG_TRACING */
+
+extern void *kmalloc_order(size_t size, gfp_t flags, unsigned int order);
+
+#ifdef CONFIG_TRACING
+extern void *kmalloc_order_trace(size_t size, gfp_t flags, unsigned int order);
+#else
+static __always_inline void *
+kmalloc_order_trace(size_t size, gfp_t flags, unsigned int order)
+{
+ return kmalloc_order(size, flags, order);
+}
+#endif
+
+static __always_inline void *kmalloc_large(size_t size, gfp_t flags)
+{
+ unsigned int order = get_order(size);
+ return kmalloc_order_trace(size, flags, order);
+}
+
+/**
+ * kmalloc - allocate memory
+ * @size: how many bytes of memory are required.
+ * @flags: the type of memory to allocate.
+ *
+ * kmalloc is the normal method of allocating memory
+ * for objects smaller than page size in the kernel.
+ *
+ * The @flags argument may be one of:
+ *
+ * %GFP_USER - Allocate memory on behalf of user. May sleep.
+ *
+ * %GFP_KERNEL - Allocate normal kernel ram. May sleep.
+ *
+ * %GFP_ATOMIC - Allocation will not sleep. May use emergency pools.
+ * For example, use this inside interrupt handlers.
+ *
+ * %GFP_HIGHUSER - Allocate pages from high memory.
+ *
+ * %GFP_NOIO - Do not do any I/O at all while trying to get memory.
+ *
+ * %GFP_NOFS - Do not make any fs calls while trying to get memory.
+ *
+ * %GFP_NOWAIT - Allocation will not sleep.
+ *
+ * %__GFP_THISNODE - Allocate node-local memory only.
+ *
+ * %GFP_DMA - Allocation suitable for DMA.
+ * Should only be used for kmalloc() caches. Otherwise, use a
+ * slab created with SLAB_DMA.
+ *
+ * Also it is possible to set different flags by OR'ing
+ * in one or more of the following additional @flags:
+ *
+ * %__GFP_COLD - Request cache-cold pages instead of
+ * trying to return cache-warm pages.
+ *
+ * %__GFP_HIGH - This allocation has high priority and may use emergency pools.
+ *
+ * %__GFP_NOFAIL - Indicate that this allocation is in no way allowed to fail
+ * (think twice before using).
+ *
+ * %__GFP_NORETRY - If memory is not immediately available,
+ * then give up at once.
+ *
+ * %__GFP_NOWARN - If allocation fails, don't issue any warnings.
+ *
+ * %__GFP_REPEAT - If allocation fails initially, try once more before failing.
+ *
+ * There are other flags available as well, but these are not intended
+ * for general use, and so are not documented here. For a full list of
+ * potential flags, always refer to linux/gfp.h.
+ */
+static __always_inline void *kmalloc(size_t size, gfp_t flags)
+{
+ if (__builtin_constant_p(size)) {
+ if (size > KMALLOC_MAX_CACHE_SIZE)
+ return kmalloc_large(size, flags);
+#ifndef CONFIG_SLOB
+ if (!(flags & GFP_DMA)) {
+ int index = kmalloc_index(size);
+
+ if (!index)
+ return ZERO_SIZE_PTR;
+
+ return kmem_cache_alloc_trace(kmalloc_caches[index],
+ flags, size);
+ }
+#endif
+ }
+ return __kmalloc(size, flags);
+}
+
+/*
+ * Determine size used for the nth kmalloc cache.
+ * return size or 0 if a kmalloc cache for that
+ * size does not exist
+ */
+static __always_inline int kmalloc_size(int n)
+{
+#ifndef CONFIG_SLOB
+ if (n > 2)
+ return 1 << n;
+
+ if (n == 1 && KMALLOC_MIN_SIZE <= 32)
+ return 96;
+
+ if (n == 2 && KMALLOC_MIN_SIZE <= 64)
+ return 192;
+#endif
+ return 0;
+}
+
+static __always_inline void *kmalloc_node(size_t size, gfp_t flags, int node)
+{
+#ifndef CONFIG_SLOB
+ if (__builtin_constant_p(size) &&
+ size <= KMALLOC_MAX_CACHE_SIZE && !(flags & GFP_DMA)) {
+ int i = kmalloc_index(size);
+
+ if (!i)
+ return ZERO_SIZE_PTR;
+
+ return kmem_cache_alloc_node_trace(kmalloc_caches[i],
+ flags, node, size);
+ }
+#endif
+ return __kmalloc_node(size, flags, node);
+}
+
+/*
+ * Setting ARCH_SLAB_MINALIGN in arch headers allows a different alignment.
+ * Intended for arches that get misalignment faults even for 64 bit integer
+ * aligned buffers.
+ */
+#ifndef ARCH_SLAB_MINALIGN
+#define ARCH_SLAB_MINALIGN __alignof__(unsigned long long)
+#endif
+
+struct memcg_cache_array {
+ struct rcu_head rcu;
+ struct kmem_cache *entries[0];
+};
+
+/*
+ * This is the main placeholder for memcg-related information in kmem caches.
+ * Both the root cache and the child caches will have it. For the root cache,
+ * this will hold a dynamically allocated array large enough to hold
+ * information about the currently limited memcgs in the system. To allow the
+ * array to be accessed without taking any locks, on relocation we free the old
+ * version only after a grace period.
+ *
+ * Child caches will hold extra metadata needed for its operation. Fields are:
+ *
+ * @memcg: pointer to the memcg this cache belongs to
+ * @root_cache: pointer to the global, root cache, this cache was derived from
+ *
+ * Both root and child caches of the same kind are linked into a list chained
+ * through @list.
+ */
+struct memcg_cache_params {
+ bool is_root_cache;
+ struct list_head list;
+ union {
+ struct memcg_cache_array __rcu *memcg_caches;
+ struct {
+ struct mem_cgroup *memcg;
+ struct kmem_cache *root_cache;
+ };
+ };
+};
+
+int memcg_update_all_caches(int num_memcgs);
+
+/**
+ * kmalloc_array - allocate memory for an array.
+ * @n: number of elements.
+ * @size: element size.
+ * @flags: the type of memory to allocate (see kmalloc).
+ */
+static inline void *kmalloc_array(size_t n, size_t size, gfp_t flags)
+{
+ if (size != 0 && n > SIZE_MAX / size)
+ return NULL;
+ return __kmalloc(n * size, flags);
+}
+
+/**
+ * kcalloc - allocate memory for an array. The memory is set to zero.
+ * @n: number of elements.
+ * @size: element size.
+ * @flags: the type of memory to allocate (see kmalloc).
+ */
+static inline void *kcalloc(size_t n, size_t size, gfp_t flags)
+{
+ return kmalloc_array(n, size, flags | __GFP_ZERO);
+}
+
+/*
+ * kmalloc_track_caller is a special version of kmalloc that records the
+ * calling function of the routine calling it for slab leak tracking instead
+ * of just the calling function (confusing, eh?).
+ * It's useful when the call to kmalloc comes from a widely-used standard
+ * allocator where we care about the real place the memory allocation
+ * request comes from.
+ */
+extern void *__kmalloc_track_caller(size_t, gfp_t, unsigned long);
+#define kmalloc_track_caller(size, flags) \
+ __kmalloc_track_caller(size, flags, _RET_IP_)
+
+#ifdef CONFIG_NUMA
+extern void *__kmalloc_node_track_caller(size_t, gfp_t, int, unsigned long);
+#define kmalloc_node_track_caller(size, flags, node) \
+ __kmalloc_node_track_caller(size, flags, node, \
+ _RET_IP_)
+
+#else /* CONFIG_NUMA */
+
+#define kmalloc_node_track_caller(size, flags, node) \
+ kmalloc_track_caller(size, flags)
+
+#endif /* CONFIG_NUMA */
+
+/*
+ * Shortcuts
+ */
+static inline void *kmem_cache_zalloc(struct kmem_cache *k, gfp_t flags)
+{
+ return kmem_cache_alloc(k, flags | __GFP_ZERO);
+}
+
+/**
+ * kzalloc - allocate memory. The memory is set to zero.
+ * @size: how many bytes of memory are required.
+ * @flags: the type of memory to allocate (see kmalloc).
+ */
+static inline void *kzalloc(size_t size, gfp_t flags)
+{
+ return kmalloc(size, flags | __GFP_ZERO);
+}
+
+/**
+ * kzalloc_node - allocate zeroed memory from a particular memory node.
+ * @size: how many bytes of memory are required.
+ * @flags: the type of memory to allocate (see kmalloc).
+ * @node: memory node from which to allocate
+ */
+static inline void *kzalloc_node(size_t size, gfp_t flags, int node)
+{
+ return kmalloc_node(size, flags | __GFP_ZERO, node);
+}
+
+unsigned int kmem_cache_size(struct kmem_cache *s);
+void __init kmem_cache_init_late(void);
+
+#endif /* _LINUX_SLAB_H */
Code Review / kvmfornfv.git / blobdiff