1/* SPDX-License-Identifier: GPL-2.0 */
  2#ifndef _MM_PERCPU_INTERNAL_H
  3#define _MM_PERCPU_INTERNAL_H
  4
  5#include <linux/types.h>
  6#include <linux/percpu.h>
  7
  8/*
  9 * pcpu_block_md is the metadata block struct.
 10 * Each chunk's bitmap is split into a number of full blocks.
 11 * All units are in terms of bits.
 12 */
 13struct pcpu_block_md {
 14	int                     contig_hint;    /* contig hint for block */
 15	int                     contig_hint_start; /* block relative starting
 16						      position of the contig hint */
 17	int                     left_free;      /* size of free space along
 18						   the left side of the block */
 19	int                     right_free;     /* size of free space along
 20						   the right side of the block */
 21	int                     first_free;     /* block position of first free */
 22};
 23
 24struct pcpu_chunk {
 25#ifdef CONFIG_PERCPU_STATS
 26	int			nr_alloc;	/* # of allocations */
 27	size_t			max_alloc_size; /* largest allocation size */
 28#endif
 29
 30	struct list_head	list;		/* linked to pcpu_slot lists */
 31	int			free_bytes;	/* free bytes in the chunk */
 32	int			contig_bits;	/* max contiguous size hint */
 33	int			contig_bits_start; /* contig_bits starting
 34						      offset */
 35	void			*base_addr;	/* base address of this chunk */
 36
 37	unsigned long		*alloc_map;	/* allocation map */
 38	unsigned long		*bound_map;	/* boundary map */
 39	struct pcpu_block_md	*md_blocks;	/* metadata blocks */
 40
 41	void			*data;		/* chunk data */
 42	int			first_bit;	/* no free below this */
 43	bool			immutable;	/* no [de]population allowed */
 44	int			start_offset;	/* the overlap with the previous
 45						   region to have a page aligned
 46						   base_addr */
 47	int			end_offset;	/* additional area required to
 48						   have the region end page
 49						   aligned */
 50
 51	int			nr_pages;	/* # of pages served by this chunk */
 52	int			nr_populated;	/* # of populated pages */
 53	int                     nr_empty_pop_pages; /* # of empty populated pages */
 54	unsigned long		populated[];	/* populated bitmap */
 55};
 56
 57extern spinlock_t pcpu_lock;
 58
 59extern struct list_head *pcpu_slot;
 60extern int pcpu_nr_slots;
 61extern int pcpu_nr_empty_pop_pages;
 62
 63extern struct pcpu_chunk *pcpu_first_chunk;
 64extern struct pcpu_chunk *pcpu_reserved_chunk;
 65
 66/**
 67 * pcpu_chunk_nr_blocks - converts nr_pages to # of md_blocks
 68 * @chunk: chunk of interest
 69 *
 70 * This conversion is from the number of physical pages that the chunk
 71 * serves to the number of bitmap blocks used.
 72 */
 73static inline int pcpu_chunk_nr_blocks(struct pcpu_chunk *chunk)
 74{
 75	return chunk->nr_pages * PAGE_SIZE / PCPU_BITMAP_BLOCK_SIZE;
 76}
 77
 78/**
 79 * pcpu_nr_pages_to_map_bits - converts the pages to size of bitmap
 80 * @pages: number of physical pages
 81 *
 82 * This conversion is from physical pages to the number of bits
 83 * required in the bitmap.
 84 */
 85static inline int pcpu_nr_pages_to_map_bits(int pages)
 86{
 87	return pages * PAGE_SIZE / PCPU_MIN_ALLOC_SIZE;
 88}
 89
 90/**
 91 * pcpu_chunk_map_bits - helper to convert nr_pages to size of bitmap
 92 * @chunk: chunk of interest
 93 *
 94 * This conversion is from the number of physical pages that the chunk
 95 * serves to the number of bits in the bitmap.
 96 */
 97static inline int pcpu_chunk_map_bits(struct pcpu_chunk *chunk)
 98{
 99	return pcpu_nr_pages_to_map_bits(chunk->nr_pages);
100}
101
102#ifdef CONFIG_PERCPU_STATS
103
104#include <linux/spinlock.h>
105
106struct percpu_stats {
107	u64 nr_alloc;		/* lifetime # of allocations */
108	u64 nr_dealloc;		/* lifetime # of deallocations */
109	u64 nr_cur_alloc;	/* current # of allocations */
110	u64 nr_max_alloc;	/* max # of live allocations */
111	u32 nr_chunks;		/* current # of live chunks */
112	u32 nr_max_chunks;	/* max # of live chunks */
113	size_t min_alloc_size;	/* min allocaiton size */
114	size_t max_alloc_size;	/* max allocation size */
115};
116
117extern struct percpu_stats pcpu_stats;
118extern struct pcpu_alloc_info pcpu_stats_ai;
119
120/*
121 * For debug purposes. We don't care about the flexible array.
122 */
123static inline void pcpu_stats_save_ai(const struct pcpu_alloc_info *ai)
124{
125	memcpy(&pcpu_stats_ai, ai, sizeof(struct pcpu_alloc_info));
126
127	/* initialize min_alloc_size to unit_size */
128	pcpu_stats.min_alloc_size = pcpu_stats_ai.unit_size;
129}
130
131/*
132 * pcpu_stats_area_alloc - increment area allocation stats
133 * @chunk: the location of the area being allocated
134 * @size: size of area to allocate in bytes
135 *
136 * CONTEXT:
137 * pcpu_lock.
138 */
139static inline void pcpu_stats_area_alloc(struct pcpu_chunk *chunk, size_t size)
140{
141	lockdep_assert_held(&pcpu_lock);
142
143	pcpu_stats.nr_alloc++;
144	pcpu_stats.nr_cur_alloc++;
145	pcpu_stats.nr_max_alloc =
146		max(pcpu_stats.nr_max_alloc, pcpu_stats.nr_cur_alloc);
147	pcpu_stats.min_alloc_size =
148		min(pcpu_stats.min_alloc_size, size);
149	pcpu_stats.max_alloc_size =
150		max(pcpu_stats.max_alloc_size, size);
151
152	chunk->nr_alloc++;
153	chunk->max_alloc_size = max(chunk->max_alloc_size, size);
154}
155
156/*
157 * pcpu_stats_area_dealloc - decrement allocation stats
158 * @chunk: the location of the area being deallocated
159 *
160 * CONTEXT:
161 * pcpu_lock.
162 */
163static inline void pcpu_stats_area_dealloc(struct pcpu_chunk *chunk)
164{
165	lockdep_assert_held(&pcpu_lock);
166
167	pcpu_stats.nr_dealloc++;
168	pcpu_stats.nr_cur_alloc--;
169
170	chunk->nr_alloc--;
171}
172
173/*
174 * pcpu_stats_chunk_alloc - increment chunk stats
175 */
176static inline void pcpu_stats_chunk_alloc(void)
177{
178	unsigned long flags;
179	spin_lock_irqsave(&pcpu_lock, flags);
180
181	pcpu_stats.nr_chunks++;
182	pcpu_stats.nr_max_chunks =
183		max(pcpu_stats.nr_max_chunks, pcpu_stats.nr_chunks);
184
185	spin_unlock_irqrestore(&pcpu_lock, flags);
186}
187
188/*
189 * pcpu_stats_chunk_dealloc - decrement chunk stats
190 */
191static inline void pcpu_stats_chunk_dealloc(void)
192{
193	unsigned long flags;
194	spin_lock_irqsave(&pcpu_lock, flags);
195
196	pcpu_stats.nr_chunks--;
197
198	spin_unlock_irqrestore(&pcpu_lock, flags);
199}
200
201#else
202
203static inline void pcpu_stats_save_ai(const struct pcpu_alloc_info *ai)
204{
205}
206
207static inline void pcpu_stats_area_alloc(struct pcpu_chunk *chunk, size_t size)
208{
209}
210
211static inline void pcpu_stats_area_dealloc(struct pcpu_chunk *chunk)
212{
213}
214
215static inline void pcpu_stats_chunk_alloc(void)
216{
217}
218
219static inline void pcpu_stats_chunk_dealloc(void)
220{
221}
222
223#endif /* !CONFIG_PERCPU_STATS */
224
225#endif