/* 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)) #endif /* __LINUX_PERCPU_H */