#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) (*({ \ preempt_disable(); \ &__get_cpu_var(var); })) /* * The weird & is necessary because sparse considers (void)(var) to be * a direct dereference of percpu variable (var). */ #define put_cpu_var(var) do { \ (void)&(var); \ preempt_enable(); \ } while (0) #ifdef CONFIG_SMP /* 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 unsigned long *pcpu_unit_offsets; struct pcpu_group_info { int nr_units; /* aligned # of units */ unsigned long base_offset; /* base address offset */ unsigned int *cpu_map; /* unit->cpu map, empty * entries contain NR_CPUS */ }; struct pcpu_alloc_info { size_t static_size; size_t reserved_size; size_t dyn_size; size_t unit_size; size_t atom_size; size_t alloc_size; size_t __ai_size; /* internal, don't use */ int nr_groups; /* 0 if grouping unnecessary */ struct pcpu_group_info groups[]; }; enum pcpu_fc { PCPU_FC_AUTO, PCPU_FC_EMBED, PCPU_FC_PAGE, PCPU_FC_NR, }; extern const char *pcpu_fc_names[PCPU_FC_NR]; extern enum pcpu_fc pcpu_chosen_fc; typedef void * (*pcpu_fc_alloc_fn_t)(unsigned int cpu, size_t size, size_t align); 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); extern struct pcpu_alloc_info * __init pcpu_alloc_alloc_info(int nr_groups, int nr_units); extern void __init pcpu_free_alloc_info(struct pcpu_alloc_info *ai); extern struct pcpu_alloc_info * __init pcpu_build_alloc_info( size_t reserved_size, ssize_t dyn_size, size_t atom_size, pcpu_fc_cpu_distance_fn_t cpu_distance_fn); extern int __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai, void *base_addr); #ifdef CONFIG_NEED_PER_CPU_EMBED_FIRST_CHUNK extern int __init pcpu_embed_first_chunk(size_t reserved_size, ssize_t dyn_size, size_t atom_size, pcpu_fc_cpu_distance_fn_t cpu_distance_fn, pcpu_fc_alloc_fn_t alloc_fn, pcpu_fc_free_fn_t free_fn); #endif #ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK extern int __init pcpu_page_first_chunk(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 /* * 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 __percpu *__alloc_reserved_percpu(size_t size, size_t align); extern void __percpu *__alloc_percpu(size_t size, size_t align); extern void free_percpu(void __percpu *__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 __percpu *__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 __percpu *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) \ (typeof(type) __percpu *)__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(var) *pr_ptr__ = &(var); \ typeof(var) pr_ret__; \ pr_ret__ = get_cpu_var(*pr_ptr__); \ put_cpu_var(*pr_ptr__); \ pr_ret__; \ }) #endif #define __percpu_generic_to_op(var, val, op) \ do { \ typeof(var) *pgto_ptr__ = &(var); \ get_cpu_var(*pgto_ptr__) op val; \ put_cpu_var(*pgto_ptr__); \ } 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 /* * Branching function to split up a function into a set of functions that * are called for different scalar sizes of the objects handled. */ extern void __bad_size_call_parameter(void); #define __pcpu_size_call_return(stem, variable) \ ({ typeof(variable) pscr_ret__; \ __verify_pcpu_ptr(&(variable)); \ switch(sizeof(variable)) { \ case 1: pscr_ret__ = stem##1(variable);break; \ case 2: pscr_ret__ = stem##2(variable);break; \ case 4: pscr_ret__ = stem##4(variable);break; \ case 8: pscr_ret__ = stem##8(variable);break; \ default: \ __bad_size_call_parameter();break; \ } \ pscr_ret__; \ }) #define __pcpu_size_call(stem, variable, ...) \ do { \ __verify_pcpu_ptr(&(variable)); \ switch(sizeof(variable)) { \ case 1: stem##1(variable, __VA_ARGS__);break; \ case 2: stem##2(variable, __VA_ARGS__);break; \ case 4: stem##4(variable, __VA_ARGS__);break; \ case 8: stem##8(variable, __VA_ARGS__);break; \ default: \ __bad_size_call_parameter();break; \ } \ } while (0) /* * Optimized manipulation for memory allocated through the per cpu * allocator or for addresses of per cpu variables. * * These operation guarantee exclusivity of access for other operations * on the *same* processor. The assumption is that per cpu data is only * accessed by a single processor instance (the current one). * * The first group is used for accesses that must be done in a * preemption safe way since we know that the context is not preempt * safe. Interrupts may occur. If the interrupt modifies the variable * too then RMW actions will not be reliable. * * The arch code can provide optimized functions in two ways: * * 1. Override the function completely. F.e. define this_cpu_add(). * The arch must then ensure that the various scalar format passed * are handled correctly. * * 2. Provide functions for certain scalar sizes. F.e. provide * this_cpu_add_2() to provide per cpu atomic operations for 2 byte * sized RMW actions. If arch code does not provide operations for * a scalar size then the fallback in the generic code will be * used. */ #define _this_cpu_generic_read(pcp) \ ({ typeof(pcp) ret__; \ preempt_disable(); \ ret__ = *this_cpu_ptr(&(pcp)); \ preempt_enable(); \ ret__; \ }) #ifndef this_cpu_read # ifndef this_cpu_read_1 # define this_cpu_read_1(pcp) _this_cpu_generic_read(pcp) # endif # ifndef this_cpu_read_2 # define this_cpu_read_2(pcp) _this_cpu_generic_read(pcp) # endif # ifndef this_cpu_read_4 # define this_cpu_read_4(pcp) _this_cpu_generic_read(pcp) # endif # ifndef this_cpu_read_8 # define this_cpu_read_8(pcp) _this_cpu_generic_read(pcp) # endif # define this_cpu_read(pcp) __pcpu_size_call_return(this_cpu_read_, (pcp)) #endif #define _this_cpu_generic_to_op(pcp, val, op) \ do { \ preempt_disable(); \ *__this_cpu_ptr(&(pcp)) op val; \ preempt_enable(); \ } while (0) #ifndef this_cpu_write # ifndef this_cpu_write_1 # define this_cpu_write_1(pcp, val) _this_cpu_generic_to_op((pcp), (val), =) # endif # ifndef this_cpu_write_2 # define this_cpu_write_2(pcp, val) _this_cpu_generic_to_op((pcp), (val), =) # endif # ifndef this_cpu_write_4 # define this_cpu_write_4(pcp, val) _this_cpu_generic_to_op((pcp), (val), =) # endif # ifndef this_cpu_write_8 # define this_cpu_write_8(pcp, val) _this_cpu_generic_to_op((pcp), (val), =) # endif # define this_cpu_write(pcp, val) __pcpu_size_call(this_cpu_write_, (pcp), (val)) #endif #ifndef this_cpu_add # ifndef this_cpu_add_1 # define this_cpu_add_1(pcp, val) _this_cpu_generic_to_op((pcp), (val), +=) # endif # ifndef this_cpu_add_2 # define this_cpu_add_2(pcp, val) _this_cpu_generic_to_op((pcp), (val), +=) # endif # ifndef this_cpu_add_4 # define this_cpu_add_4(pcp, val) _this_cpu_generic_to_op((pcp), (val), +=) # endif # ifndef this_cpu_add_8 # define this_cpu_add_8(pcp, val) _this_cpu_generic_to_op((pcp), (val), +=) # endif # define this_cpu_add(pcp, val) __pcpu_size_call(this_cpu_add_, (pcp), (val)) #endif #ifndef this_cpu_sub # define this_cpu_sub(pcp, val) this_cpu_add((pcp), -(val)) #endif #ifndef this_cpu_inc # define this_cpu_inc(pcp) this_cpu_add((pcp), 1) #endif #ifndef this_cpu_dec # define this_cpu_dec(pcp) this_cpu_sub((pcp), 1) #endif #ifndef this_cpu_and # ifndef this_cpu_and_1 # define this_cpu_and_1(pcp, val) _this_cpu_generic_to_op((pcp), (val), &=) # endif # ifndef this_cpu_and_2 # define this_cpu_and_2(pcp, val) _this_cpu_generic_to_op((pcp), (val), &=) # endif # ifndef this_cpu_and_4 # define this_cpu_and_4(pcp, val) _this_cpu_generic_to_op((pcp), (val), &=) # endif # ifndef this_cpu_and_8 # define this_cpu_and_8(pcp, val) _this_cpu_generic_to_op((pcp), (val), &=) # endif # define this_cpu_and(pcp, val) __pcpu_size_call(this_cpu_and_, (pcp), (val)) #endif #ifndef this_cpu_or # ifndef this_cpu_or_1 # define this_cpu_or_1(pcp, val) _this_cpu_generic_to_op((pcp), (val), |=) # endif # ifndef this_cpu_or_2 # define this_cpu_or_2(pcp, val) _this_cpu_generic_to_op((pcp), (val), |=) # endif # ifndef this_cpu_or_4 # define this_cpu_or_4(pcp, val) _this_cpu_generic_to_op((pcp), (val), |=) # endif # ifndef this_cpu_or_8 # define this_cpu_or_8(pcp, val) _this_cpu_generic_to_op((pcp), (val), |=) # endif # define this_cpu_or(pcp, val) __pcpu_size_call(this_cpu_or_, (pcp), (val)) #endif #ifndef this_cpu_xor # ifndef this_cpu_xor_1 # define this_cpu_xor_1(pcp, val) _this_cpu_generic_to_op((pcp), (val), ^=) # endif # ifndef this_cpu_xor_2 # define this_cpu_xor_2(pcp, val) _this_cpu_generic_to_op((pcp), (val), ^=) # endif # ifndef this_cpu_xor_4 # define this_cpu_xor_4(pcp, val) _this_cpu_generic_to_op((pcp), (val), ^=) # endif # ifndef this_cpu_xor_8 # define this_cpu_xor_8(pcp, val) _this_cpu_generic_to_op((pcp), (val), ^=) # endif # define this_cpu_xor(pcp, val) __pcpu_size_call(this_cpu_or_, (pcp), (val)) #endif /* * Generic percpu operations that do not require preemption handling. * Either we do not care about races or the caller has the * responsibility of handling preemptions issues. Arch code can still * override these instructions since the arch per cpu code may be more * efficient and may actually get race freeness for free (that is the * case for x86 for example). * * If there is no other protection through preempt disable and/or * disabling interupts then one of these RMW operations can show unexpected * behavior because the execution thread was rescheduled on another processor * or an interrupt occurred and the same percpu variable was modified from * the interrupt context. */ #ifndef __this_cpu_read # ifndef __this_cpu_read_1 # define __this_cpu_read_1(pcp) (*__this_cpu_ptr(&(pcp))) # endif # ifndef __this_cpu_read_2 # define __this_cpu_read_2(pcp) (*__this_cpu_ptr(&(pcp))) # endif # ifndef __this_cpu_read_4 # define __this_cpu_read_4(pcp) (*__this_cpu_ptr(&(pcp))) # endif # ifndef __this_cpu_read_8 # define __this_cpu_read_8(pcp) (*__this_cpu_ptr(&(pcp))) # endif # define __this_cpu_read(pcp) __pcpu_size_call_return(__this_cpu_read_, (pcp)) #endif #define __this_cpu_generic_to_op(pcp, val, op) \ do { \ *__this_cpu_ptr(&(pcp)) op val; \ } while (0) #ifndef __this_cpu_write # ifndef __this_cpu_write_1 # define __this_cpu_write_1(pcp, val) __this_cpu_generic_to_op((pcp), (val), =) # endif # ifndef __this_cpu_write_2 # define __this_cpu_write_2(pcp, val) __this_cpu_generic_to_op((pcp), (val), =) # endif # ifndef __this_cpu_write_4 # define __this_cpu_write_4(pcp, val) __this_cpu_generic_to_op((pcp), (val), =) # endif # ifndef __this_cpu_write_8 # define __this_cpu_write_8(pcp, val) __this_cpu_generic_to_op((pcp), (val), =) # endif # define __this_cpu_write(pcp, val) __pcpu_size_call(__this_cpu_write_, (pcp), (val)) #endif #ifndef __this_cpu_add # ifndef __this_cpu_add_1 # define __this_cpu_add_1(pcp, val) __this_cpu_generic_to_op((pcp), (val), +=) # endif # ifndef __this_cpu_add_2 # define __this_cpu_add_2(pcp, val) __this_cpu_generic_to_op((pcp), (val), +=) # endif # ifndef __this_cpu_add_4 # define __this_cpu_add_4(pcp, val) __this_cpu_generic_to_op((pcp), (val), +=) # endif # ifndef __this_cpu_add_8 # define __this_cpu_add_8(pcp, val) __this_cpu_generic_to_op((pcp), (val), +=) # endif # define __this_cpu_add(pcp, val) __pcpu_size_call(__this_cpu_add_, (pcp), (val)) #endif #ifndef __this_cpu_sub # define __this_cpu_sub(pcp, val) __this_cpu_add((pcp), -(val)) #endif #ifndef __this_cpu_inc # define __this_cpu_inc(pcp) __this_cpu_add((pcp), 1) #endif #ifndef __this_cpu_dec # define __this_cpu_dec(pcp) __this_cpu_sub((pcp), 1) #endif #ifndef __this_cpu_and # ifndef __this_cpu_and_1 # define __this_cpu_and_1(pcp, val) __this_cpu_generic_to_op((pcp), (val), &=) # endif # ifndef __this_cpu_and_2 # define __this_cpu_and_2(pcp, val) __this_cpu_generic_to_op((pcp), (val), &=) # endif # ifndef __this_cpu_and_4 # define __this_cpu_and_4(pcp, val) __this_cpu_generic_to_op((pcp), (val), &=) # endif # ifndef __this_cpu_and_8 # define __this_cpu_and_8(pcp, val) __this_cpu_generic_to_op((pcp), (val), &=) # endif # define __this_cpu_and(pcp, val) __pcpu_size_call(__this_cpu_and_, (pcp), (val)) #endif #ifndef __this_cpu_or # ifndef __this_cpu_or_1 # define __this_cpu_or_1(pcp, val) __this_cpu_generic_to_op((pcp), (val), |=) # endif # ifndef __this_cpu_or_2 # define __this_cpu_or_2(pcp, val) __this_cpu_generic_to_op((pcp), (val), |=) # endif # ifndef __this_cpu_or_4 # define __this_cpu_or_4(pcp, val) __this_cpu_generic_to_op((pcp), (val), |=) # endif # ifndef __this_cpu_or_8 # define __this_cpu_or_8(pcp, val) __this_cpu_generic_to_op((pcp), (val), |=) # endif # define __this_cpu_or(pcp, val) __pcpu_size_call(__this_cpu_or_, (pcp), (val)) #endif #ifndef __this_cpu_xor # ifndef __this_cpu_xor_1 # define __this_cpu_xor_1(pcp, val) __this_cpu_generic_to_op((pcp), (val), ^=) # endif # ifndef __this_cpu_xor_2 # define __this_cpu_xor_2(pcp, val) __this_cpu_generic_to_op((pcp), (val), ^=) # endif # ifndef __this_cpu_xor_4 # define __this_cpu_xor_4(pcp, val) __this_cpu_generic_to_op((pcp), (val), ^=) # endif # ifndef __this_cpu_xor_8 # define __this_cpu_xor_8(pcp, val) __this_cpu_generic_to_op((pcp), (val), ^=) # endif # define __this_cpu_xor(pcp, val) __pcpu_size_call(__this_cpu_xor_, (pcp), (val)) #endif /* * IRQ safe versions of the per cpu RMW operations. Note that these operations * are *not* safe against modification of the same variable from another * processors (which one gets when using regular atomic operations) . They are guaranteed to be atomic vs. local interrupts and * preemption only. */ #define irqsafe_cpu_generic_to_op(pcp, val, op) \ do { \ unsigned long flags; \ local_irq_save(flags); \ *__this_cpu_ptr(&(pcp)) op val; \ local_irq_restore(flags); \ } while (0) #ifndef irqsafe_cpu_add # ifndef irqsafe_cpu_add_1 # define irqsafe_cpu_add_1(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), +=) # endif # ifndef irqsafe_cpu_add_2 # define irqsafe_cpu_add_2(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), +=) # endif # ifndef irqsafe_cpu_add_4 # define irqsafe_cpu_add_4(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), +=) # endif # ifndef irqsafe_cpu_add_8 # define irqsafe_cpu_add_8(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), +=) # endif # define irqsafe_cpu_add(pcp, val) __pcpu_size_call(irqsafe_cpu_add_, (pcp), (val)) #endif #ifndef irqsafe_cpu_sub # define irqsafe_cpu_sub(pcp, val) irqsafe_cpu_add((pcp), -(val)) #endif #ifndef irqsafe_cpu_inc # define irqsafe_cpu_inc(pcp) irqsafe_cpu_add((pcp), 1) #endif #ifndef irqsafe_cpu_dec # define irqsafe_cpu_dec(pcp) irqsafe_cpu_sub((pcp), 1) #endif #ifndef irqsafe_cpu_and # ifndef irqsafe_cpu_and_1 # define irqsafe_cpu_and_1(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), &=) # endif # ifndef irqsafe_cpu_and_2 # define irqsafe_cpu_and_2(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), &=) # endif # ifndef irqsafe_cpu_and_4 # define irqsafe_cpu_and_4(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), &=) # endif # ifndef irqsafe_cpu_and_8 # define irqsafe_cpu_and_8(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), &=) # endif # define irqsafe_cpu_and(pcp, val) __pcpu_size_call(irqsafe_cpu_and_, (val)) #endif #ifndef irqsafe_cpu_or # ifndef irqsafe_cpu_or_1 # define irqsafe_cpu_or_1(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), |=) # endif # ifndef irqsafe_cpu_or_2 # define irqsafe_cpu_or_2(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), |=) # endif # ifndef irqsafe_cpu_or_4 # define irqsafe_cpu_or_4(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), |=) # endif # ifndef irqsafe_cpu_or_8 # define irqsafe_cpu_or_8(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), |=) # endif # define irqsafe_cpu_or(pcp, val) __pcpu_size_call(irqsafe_cpu_or_, (val)) #endif #ifndef irqsafe_cpu_xor # ifndef irqsafe_cpu_xor_1 # define irqsafe_cpu_xor_1(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), ^=) # endif # ifndef irqsafe_cpu_xor_2 # define irqsafe_cpu_xor_2(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), ^=) # endif # ifndef irqsafe_cpu_xor_4 # define irqsafe_cpu_xor_4(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), ^=) # endif # ifndef irqsafe_cpu_xor_8 # define irqsafe_cpu_xor_8(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), ^=) # endif # define irqsafe_cpu_xor(pcp, val) __pcpu_size_call(irqsafe_cpu_xor_, (val)) #endif #endif /* __LINUX_PERCPU_H */