#ifndef __LINUX_PERCPU_H #define __LINUX_PERCPU_H #include <linux/preempt.h> #include <linux/slab.h> /* For kmalloc() */ #include <linux/smp.h> #include <linux/cpumask.h> #include <linux/pfn.h> #include <asm/percpu.h> #ifndef PER_CPU_BASE_SECTION #ifdef CONFIG_SMP #define PER_CPU_BASE_SECTION ".data.percpu" #else #define PER_CPU_BASE_SECTION ".data" #endif #endif #ifdef CONFIG_SMP #ifdef MODULE #define PER_CPU_SHARED_ALIGNED_SECTION "" #else #define PER_CPU_SHARED_ALIGNED_SECTION ".shared_aligned" #endif #define PER_CPU_FIRST_SECTION ".first" #else #define PER_CPU_SHARED_ALIGNED_SECTION "" #define PER_CPU_FIRST_SECTION "" #endif #define DEFINE_PER_CPU_SECTION(type, name, section) \ __attribute__((__section__(PER_CPU_BASE_SECTION section))) \ PER_CPU_ATTRIBUTES __typeof__(type) per_cpu__##name #define DEFINE_PER_CPU(type, name) \ DEFINE_PER_CPU_SECTION(type, name, "") #define DEFINE_PER_CPU_SHARED_ALIGNED(type, name) \ DEFINE_PER_CPU_SECTION(type, name, PER_CPU_SHARED_ALIGNED_SECTION) \ ____cacheline_aligned_in_smp #define DEFINE_PER_CPU_PAGE_ALIGNED(type, name) \ DEFINE_PER_CPU_SECTION(type, name, ".page_aligned") #define DEFINE_PER_CPU_FIRST(type, name) \ DEFINE_PER_CPU_SECTION(type, name, PER_CPU_FIRST_SECTION) #define EXPORT_PER_CPU_SYMBOL(var) EXPORT_SYMBOL(per_cpu__##var) #define EXPORT_PER_CPU_SYMBOL_GPL(var) EXPORT_SYMBOL_GPL(per_cpu__##var) /* 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 #ifdef CONFIG_HAVE_DYNAMIC_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; typedef struct page * (*pcpu_get_page_fn_t)(unsigned int cpu, int pageno); typedef void (*pcpu_populate_pte_fn_t)(unsigned long addr); extern size_t __init pcpu_setup_first_chunk(pcpu_get_page_fn_t get_page_fn, size_t static_size, size_t reserved_size, ssize_t dyn_size, ssize_t unit_size, void *base_addr, pcpu_populate_pte_fn_t populate_pte_fn); extern ssize_t __init pcpu_embed_first_chunk( size_t static_size, size_t reserved_size, ssize_t dyn_size, ssize_t unit_size); /* * 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_DYNAMIC_PER_CPU_AREA */ struct percpu_data { void *ptrs[1]; }; #define __percpu_disguise(pdata) (struct percpu_data *)~(unsigned long)(pdata) #define per_cpu_ptr(ptr, cpu) \ ({ \ struct percpu_data *__p = __percpu_disguise(ptr); \ (__typeof__(ptr))__p->ptrs[(cpu)]; \ }) #endif /* CONFIG_HAVE_DYNAMIC_PER_CPU_AREA */ extern void *__alloc_percpu(size_t size, size_t align); extern void free_percpu(void *__pdata); #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); } #endif /* CONFIG_SMP */ #define alloc_percpu(type) (type *)__alloc_percpu(sizeof(type), \ __alignof__(type)) #endif /* __LINUX_PERCPU_H */