155 lines
		
	
	
		
			5.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			155 lines
		
	
	
		
			5.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /* SPDX-License-Identifier: GPL-2.0 */
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| #ifndef __LINUX_PERCPU_H
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| #define __LINUX_PERCPU_H
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| 
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| #include <linux/mmdebug.h>
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| #include <linux/preempt.h>
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| #include <linux/smp.h>
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| #include <linux/cpumask.h>
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| #include <linux/printk.h>
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| #include <linux/pfn.h>
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| #include <linux/init.h>
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| 
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| #include <asm/percpu.h>
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| 
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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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| 
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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(32 << 10)
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| 
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| /* minimum allocation size and shift in bytes */
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| #define PCPU_MIN_ALLOC_SHIFT		2
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| #define PCPU_MIN_ALLOC_SIZE		(1 << PCPU_MIN_ALLOC_SHIFT)
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| 
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| /* number of bits per page, used to trigger a scan if blocks are > PAGE_SIZE */
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| #define PCPU_BITS_PER_PAGE		(PAGE_SIZE >> PCPU_MIN_ALLOC_SHIFT)
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| 
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| /*
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|  * This determines the size of each metadata block.  There are several subtle
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|  * constraints around this constant.  The reserved region must be a multiple of
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|  * PCPU_BITMAP_BLOCK_SIZE.  Additionally, PCPU_BITMAP_BLOCK_SIZE must be a
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|  * multiple of PAGE_SIZE or PAGE_SIZE must be a multiple of
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|  * PCPU_BITMAP_BLOCK_SIZE to align with the populated page map. The unit_size
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|  * also has to be a multiple of PCPU_BITMAP_BLOCK_SIZE to ensure full blocks.
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|  */
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| #define PCPU_BITMAP_BLOCK_SIZE		PAGE_SIZE
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| #define PCPU_BITMAP_BLOCK_BITS		(PCPU_BITMAP_BLOCK_SIZE >>	\
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| 					 PCPU_MIN_ALLOC_SHIFT)
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| 
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| /*
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|  * Percpu allocator can serve percpu allocations before slab is
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|  * initialized which allows slab to depend on the percpu allocator.
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|  * The following two parameters decide how much resource to
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|  * preallocate for this.  Keep PERCPU_DYNAMIC_RESERVE equal to or
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|  * larger than PERCPU_DYNAMIC_EARLY_SIZE.
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|  */
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| #define PERCPU_DYNAMIC_EARLY_SLOTS	128
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| #define PERCPU_DYNAMIC_EARLY_SIZE	(12 << 10)
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| 
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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		(28 << 10)
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| #else
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| #define PERCPU_DYNAMIC_RESERVE		(20 << 10)
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| #endif
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| 
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| extern void *pcpu_base_addr;
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| extern const unsigned long *pcpu_unit_offsets;
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| 
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| struct pcpu_group_info {
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| 	int			nr_units;	/* aligned # of units */
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| 	unsigned long		base_offset;	/* base address offset */
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| 	unsigned int		*cpu_map;	/* unit->cpu map, empty
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| 						 * entries contain NR_CPUS */
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| };
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| 
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| struct pcpu_alloc_info {
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| 	size_t			static_size;
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| 	size_t			reserved_size;
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| 	size_t			dyn_size;
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| 	size_t			unit_size;
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| 	size_t			atom_size;
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| 	size_t			alloc_size;
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| 	size_t			__ai_size;	/* internal, don't use */
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| 	int			nr_groups;	/* 0 if grouping unnecessary */
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| 	struct pcpu_group_info	groups[];
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| };
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| 
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| enum pcpu_fc {
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| 	PCPU_FC_AUTO,
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| 	PCPU_FC_EMBED,
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| 	PCPU_FC_PAGE,
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| 
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| 	PCPU_FC_NR,
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| };
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| extern const char * const pcpu_fc_names[PCPU_FC_NR];
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| 
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| extern enum pcpu_fc pcpu_chosen_fc;
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| 
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| typedef void * (*pcpu_fc_alloc_fn_t)(unsigned int cpu, size_t size,
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| 				     size_t align);
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| typedef void (*pcpu_fc_free_fn_t)(void *ptr, size_t size);
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| typedef void (*pcpu_fc_populate_pte_fn_t)(unsigned long addr);
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| typedef int (pcpu_fc_cpu_distance_fn_t)(unsigned int from, unsigned int to);
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| 
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| extern struct pcpu_alloc_info * __init pcpu_alloc_alloc_info(int nr_groups,
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| 							     int nr_units);
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| extern void __init pcpu_free_alloc_info(struct pcpu_alloc_info *ai);
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| 
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| extern int __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai,
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| 					 void *base_addr);
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| 
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| #ifdef CONFIG_NEED_PER_CPU_EMBED_FIRST_CHUNK
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| extern int __init pcpu_embed_first_chunk(size_t reserved_size, size_t dyn_size,
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| 				size_t atom_size,
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| 				pcpu_fc_cpu_distance_fn_t cpu_distance_fn,
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| 				pcpu_fc_alloc_fn_t alloc_fn,
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| 				pcpu_fc_free_fn_t free_fn);
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| #endif
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| 
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| #ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK
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| extern int __init pcpu_page_first_chunk(size_t reserved_size,
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| 				pcpu_fc_alloc_fn_t alloc_fn,
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| 				pcpu_fc_free_fn_t free_fn,
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| 				pcpu_fc_populate_pte_fn_t populate_pte_fn);
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| #endif
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| 
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| extern void __percpu *__alloc_reserved_percpu(size_t size, size_t align);
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| extern bool __is_kernel_percpu_address(unsigned long addr, unsigned long *can_addr);
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| extern bool is_kernel_percpu_address(unsigned long addr);
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| 
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| #if !defined(CONFIG_SMP) || !defined(CONFIG_HAVE_SETUP_PER_CPU_AREA)
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| extern void __init setup_per_cpu_areas(void);
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| #endif
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| 
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| extern void __percpu *__alloc_percpu_gfp(size_t size, size_t align, gfp_t gfp);
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| extern void __percpu *__alloc_percpu(size_t size, size_t align);
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| extern void free_percpu(void __percpu *__pdata);
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| extern phys_addr_t per_cpu_ptr_to_phys(void *addr);
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| 
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| #define alloc_percpu_gfp(type, gfp)					\
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| 	(typeof(type) __percpu *)__alloc_percpu_gfp(sizeof(type),	\
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| 						__alignof__(type), gfp)
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| #define alloc_percpu(type)						\
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| 	(typeof(type) __percpu *)__alloc_percpu(sizeof(type),		\
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| 						__alignof__(type))
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| 
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| extern unsigned long pcpu_nr_pages(void);
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| 
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| #endif /* __LINUX_PERCPU_H */
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