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Diffstat (limited to '')
| -rw-r--r-- | include/linux/percpu.h | 154 |
1 files changed, 154 insertions, 0 deletions
diff --git a/include/linux/percpu.h b/include/linux/percpu.h new file mode 100644 index 000000000..70b7123f3 --- /dev/null +++ b/include/linux/percpu.h @@ -0,0 +1,154 @@ +/* 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 */ |