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