#ifndef __LINUX_PERCPU_H #define __LINUX_PERCPU_H #include #include /* For kmalloc() */ #include #include #include #include /* enough to cover all DEFINE_PER_CPUs in modules */ #ifdef CONFIG_MODULES #define PERCPU_MODULE_RESERVE (8 << 10) #else #define PERCPU_MODULE_RESERVE 0 #endif #ifndef PERCPU_ENOUGH_ROOM #define PERCPU_ENOUGH_ROOM \ (ALIGN(__per_cpu_end - __per_cpu_start, SMP_CACHE_BYTES) + \ PERCPU_MODULE_RESERVE) #endif /* * Must be an lvalue. Since @var must be a simple identifier, * we force a syntax error here if it isn't. */ #define get_cpu_var(var) (*({ \ extern int simple_identifier_##var(void); \ preempt_disable(); \ &__get_cpu_var(var); })) #define put_cpu_var(var) preempt_enable() #ifdef CONFIG_SMP #ifndef CONFIG_HAVE_LEGACY_PER_CPU_AREA /* minimum unit size, also is the maximum supported allocation size */ #define PCPU_MIN_UNIT_SIZE PFN_ALIGN(64 << 10) /* * PERCPU_DYNAMIC_RESERVE indicates the amount of free area to piggy * back on the first chunk for dynamic percpu allocation if arch is * manually allocating and mapping it for faster access (as a part of * large page mapping for example). * * The following values give between one and two pages of free space * after typical minimal boot (2-way SMP, single disk and NIC) with * both defconfig and a distro config on x86_64 and 32. More * intelligent way to determine this would be nice. */ #if BITS_PER_LONG > 32 #define PERCPU_DYNAMIC_RESERVE (20 << 10) #else #define PERCPU_DYNAMIC_RESERVE (12 << 10) #endif extern void *pcpu_base_addr; extern const int *pcpu_unit_map; typedef void * (*pcpu_fc_alloc_fn_t)(unsigned int cpu, size_t size); typedef void (*pcpu_fc_free_fn_t)(void *ptr, size_t size); typedef void (*pcpu_fc_populate_pte_fn_t)(unsigned long addr); typedef int (pcpu_fc_cpu_distance_fn_t)(unsigned int from, unsigned int to); typedef void (*pcpu_fc_map_fn_t)(void *ptr, size_t size, void *addr); extern size_t __init pcpu_setup_first_chunk( size_t static_size, size_t reserved_size, ssize_t dyn_size, size_t unit_size, void *base_addr, const int *unit_map); #ifdef CONFIG_NEED_PER_CPU_EMBED_FIRST_CHUNK extern ssize_t __init pcpu_embed_first_chunk( size_t static_size, size_t reserved_size, ssize_t dyn_size); #endif #ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK extern ssize_t __init pcpu_page_first_chunk( size_t static_size, size_t reserved_size, pcpu_fc_alloc_fn_t alloc_fn, pcpu_fc_free_fn_t free_fn, pcpu_fc_populate_pte_fn_t populate_pte_fn); #endif #ifdef CONFIG_NEED_PER_CPU_LPAGE_FIRST_CHUNK extern int __init pcpu_lpage_build_unit_map( size_t static_size, size_t reserved_size, ssize_t *dyn_sizep, size_t *unit_sizep, size_t lpage_size, int *unit_map, pcpu_fc_cpu_distance_fn_t cpu_distance_fn); extern ssize_t __init pcpu_lpage_first_chunk( size_t static_size, size_t reserved_size, size_t dyn_size, size_t unit_size, size_t lpage_size, const int *unit_map, int nr_units, pcpu_fc_alloc_fn_t alloc_fn, pcpu_fc_free_fn_t free_fn, pcpu_fc_map_fn_t map_fn); extern void *pcpu_lpage_remapped(void *kaddr); #else static inline void *pcpu_lpage_remapped(void *kaddr) { return NULL; } #endif /* * Use this to get to a cpu's version of the per-cpu object * dynamically allocated. Non-atomic access to the current CPU's * version should probably be combined with get_cpu()/put_cpu(). */ #define per_cpu_ptr(ptr, cpu) SHIFT_PERCPU_PTR((ptr), per_cpu_offset((cpu))) extern void *__alloc_reserved_percpu(size_t size, size_t align); #else /* CONFIG_HAVE_LEGACY_PER_CPU_AREA */ struct percpu_data { void *ptrs[1]; }; /* pointer disguising messes up the kmemleak objects tracking */ #ifndef CONFIG_DEBUG_KMEMLEAK #define __percpu_disguise(pdata) (struct percpu_data *)~(unsigned long)(pdata) #else #define __percpu_disguise(pdata) (struct percpu_data *)(pdata) #endif #define per_cpu_ptr(ptr, cpu) \ ({ \ struct percpu_data *__p = __percpu_disguise(ptr); \ (__typeof__(ptr))__p->ptrs[(cpu)]; \ }) #endif /* CONFIG_HAVE_LEGACY_PER_CPU_AREA */ extern void *__alloc_percpu(size_t size, size_t align); extern void free_percpu(void *__pdata); #ifndef CONFIG_HAVE_SETUP_PER_CPU_AREA extern void __init setup_per_cpu_areas(void); #endif #else /* CONFIG_SMP */ #define per_cpu_ptr(ptr, cpu) ({ (void)(cpu); (ptr); }) static inline void *__alloc_percpu(size_t size, size_t align) { /* * Can't easily make larger alignment work with kmalloc. WARN * on it. Larger alignment should only be used for module * percpu sections on SMP for which this path isn't used. */ WARN_ON_ONCE(align > SMP_CACHE_BYTES); return kzalloc(size, GFP_KERNEL); } static inline void free_percpu(void *p) { kfree(p); } static inline void __init setup_per_cpu_areas(void) { } static inline void *pcpu_lpage_remapped(void *kaddr) { return NULL; } #endif /* CONFIG_SMP */ #define alloc_percpu(type) (type *)__alloc_percpu(sizeof(type), \ __alignof__(type)) /* * Optional methods for optimized non-lvalue per-cpu variable access. * * @var can be a percpu variable or a field of it and its size should * equal char, int or long. percpu_read() evaluates to a lvalue and * all others to void. * * These operations are guaranteed to be atomic w.r.t. preemption. * The generic versions use plain get/put_cpu_var(). Archs are * encouraged to implement single-instruction alternatives which don't * require preemption protection. */ #ifndef percpu_read # define percpu_read(var) \ ({ \ typeof(per_cpu_var(var)) __tmp_var__; \ __tmp_var__ = get_cpu_var(var); \ put_cpu_var(var); \ __tmp_var__; \ }) #endif #define __percpu_generic_to_op(var, val, op) \ do { \ get_cpu_var(var) op val; \ put_cpu_var(var); \ } while (0) #ifndef percpu_write # define percpu_write(var, val) __percpu_generic_to_op(var, (val), =) #endif #ifndef percpu_add # define percpu_add(var, val) __percpu_generic_to_op(var, (val), +=) #endif #ifndef percpu_sub # define percpu_sub(var, val) __percpu_generic_to_op(var, (val), -=) #endif #ifndef percpu_and # define percpu_and(var, val) __percpu_generic_to_op(var, (val), &=) #endif #ifndef percpu_or # define percpu_or(var, val) __percpu_generic_to_op(var, (val), |=) #endif #ifndef percpu_xor # define percpu_xor(var, val) __percpu_generic_to_op(var, (val), ^=) #endif #endif /* __LINUX_PERCPU_H */