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/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __LINUX_PERCPU_H
#define __LINUX_PERCPU_H
#include <linux/mmdebug.h>
#include <linux/preempt.h>
#include <linux/smp.h>
#include <linux/cpumask.h>
#include <linux/printk.h>
#include <linux/pfn.h>
#include <linux/init.h>
#include <asm/percpu.h>
/* 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
/* minimum unit size, also is the maximum supported allocation size */
#define PCPU_MIN_UNIT_SIZE PFN_ALIGN(32 << 10)
/* minimum allocation size and shift in bytes */
#define PCPU_MIN_ALLOC_SHIFT 2
#define PCPU_MIN_ALLOC_SIZE (1 << PCPU_MIN_ALLOC_SHIFT)
/* number of bits per page, used to trigger a scan if blocks are > PAGE_SIZE */
#define PCPU_BITS_PER_PAGE (PAGE_SIZE >> PCPU_MIN_ALLOC_SHIFT)
/*
* This determines the size of each metadata block. There are several subtle
* constraints around this constant. The reserved region must be a multiple of
* PCPU_BITMAP_BLOCK_SIZE. Additionally, PCPU_BITMAP_BLOCK_SIZE must be a
* multiple of PAGE_SIZE or PAGE_SIZE must be a multiple of
* PCPU_BITMAP_BLOCK_SIZE to align with the populated page map. The unit_size
* also has to be a multiple of PCPU_BITMAP_BLOCK_SIZE to ensure full blocks.
*/
#define PCPU_BITMAP_BLOCK_SIZE PAGE_SIZE
#define PCPU_BITMAP_BLOCK_BITS (PCPU_BITMAP_BLOCK_SIZE >> \
PCPU_MIN_ALLOC_SHIFT)
/*
* Percpu allocator can serve percpu allocations before slab is
* initialized which allows slab to depend on the percpu allocator.
* The following two parameters decide how much resource to
* preallocate for this. Keep PERCPU_DYNAMIC_RESERVE equal to or
* larger than PERCPU_DYNAMIC_EARLY_SIZE.
*/
#define PERCPU_DYNAMIC_EARLY_SLOTS 128
#define PERCPU_DYNAMIC_EARLY_SIZE (12 << 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 (28 << 10)
#else
#define PERCPU_DYNAMIC_RESERVE (20 << 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 * const 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 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, size_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
extern void __percpu *__alloc_reserved_percpu(size_t size, size_t align);
extern bool __is_kernel_percpu_address(unsigned long addr, unsigned long *can_addr);
extern bool is_kernel_percpu_address(unsigned long addr);
#if !defined(CONFIG_SMP) || !defined(CONFIG_HAVE_SETUP_PER_CPU_AREA)
extern void __init setup_per_cpu_areas(void);
#endif
extern void __percpu *__alloc_percpu_gfp(size_t size, size_t align, gfp_t gfp);
extern void __percpu *__alloc_percpu(size_t size, size_t align);
extern void free_percpu(void __percpu *__pdata);
extern phys_addr_t per_cpu_ptr_to_phys(void *addr);
#define alloc_percpu_gfp(type, gfp) \
(typeof(type) __percpu *)__alloc_percpu_gfp(sizeof(type), \
__alignof__(type), gfp)
#define alloc_percpu(type) \
(typeof(type) __percpu *)__alloc_percpu(sizeof(type), \
__alignof__(type))
extern unsigned long pcpu_nr_pages(void);
#endif /* __LINUX_PERCPU_H */
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