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 *
 13 * The scan hint is the largest known contiguous area before the contig hint.
 14 * It is not necessarily the actual largest contig hint though.  There is an
 15 * invariant that the scan_hint_start > contig_hint_start iff
 16 * scan_hint == contig_hint.  This is necessary because when scanning forward,
 17 * we don't know if a new contig hint would be better than the current one.
 18 */
 19struct pcpu_block_md {
 20	int			scan_hint;	/* scan hint for block */
 21	int			scan_hint_start; /* block relative starting
 22						    position of the scan hint */
 23	int                     contig_hint;    /* contig hint for block */
 24	int                     contig_hint_start; /* block relative starting
 25						      position of the contig hint */
 26	int                     left_free;      /* size of free space along
 27						   the left side of the block */
 28	int                     right_free;     /* size of free space along
 29						   the right side of the block */
 30	int                     first_free;     /* block position of first free */
 31	int			nr_bits;	/* total bits responsible for */
 32};
 33
 34struct pcpu_chunk {
 35#ifdef CONFIG_PERCPU_STATS
 36	int			nr_alloc;	/* # of allocations */
 37	size_t			max_alloc_size; /* largest allocation size */
 38#endif
 39
 40	struct list_head	list;		/* linked to pcpu_slot lists */
 41	int			free_bytes;	/* free bytes in the chunk */
 42	struct pcpu_block_md	chunk_md;
 43	void			*base_addr;	/* base address of this chunk */
 44
 45	unsigned long		*alloc_map;	/* allocation map */
 46	unsigned long		*bound_map;	/* boundary map */
 47	struct pcpu_block_md	*md_blocks;	/* metadata blocks */
 48
 49	void			*data;		/* chunk data */
 50	bool			immutable;	/* no [de]population allowed */
 51	bool			isolated;	/* isolated from active chunk
 52						   slots */
 53	int			start_offset;	/* the overlap with the previous
 54						   region to have a page aligned
 55						   base_addr */
 56	int			end_offset;	/* additional area required to
 57						   have the region end page
 58						   aligned */
 59#ifdef CONFIG_MEMCG_KMEM
 60	struct obj_cgroup	**obj_cgroups;	/* vector of object cgroups */
 61#endif
 62
 63	int			nr_pages;	/* # of pages served by this chunk */
 64	int			nr_populated;	/* # of populated pages */
 65	int                     nr_empty_pop_pages; /* # of empty populated pages */
 66	unsigned long		populated[];	/* populated bitmap */
 67};
 68
 69extern spinlock_t pcpu_lock;
 70
 71extern struct list_head *pcpu_chunk_lists;
 72extern int pcpu_nr_slots;
 73extern int pcpu_sidelined_slot;
 74extern int pcpu_to_depopulate_slot;
 75extern int pcpu_nr_empty_pop_pages;
 76
 77extern struct pcpu_chunk *pcpu_first_chunk;
 78extern struct pcpu_chunk *pcpu_reserved_chunk;
 79
 80/**
 81 * pcpu_chunk_nr_blocks - converts nr_pages to # of md_blocks
 82 * @chunk: chunk of interest
 83 *
 84 * This conversion is from the number of physical pages that the chunk
 85 * serves to the number of bitmap blocks used.
 86 */
 87static inline int pcpu_chunk_nr_blocks(struct pcpu_chunk *chunk)
 88{
 89	return chunk->nr_pages * PAGE_SIZE / PCPU_BITMAP_BLOCK_SIZE;
 90}
 91
 92/**
 93 * pcpu_nr_pages_to_map_bits - converts the pages to size of bitmap
 94 * @pages: number of physical pages
 95 *
 96 * This conversion is from physical pages to the number of bits
 97 * required in the bitmap.
 98 */
 99static inline int pcpu_nr_pages_to_map_bits(int pages)
100{
101	return pages * PAGE_SIZE / PCPU_MIN_ALLOC_SIZE;
102}
103
104/**
105 * pcpu_chunk_map_bits - helper to convert nr_pages to size of bitmap
106 * @chunk: chunk of interest
107 *
108 * This conversion is from the number of physical pages that the chunk
109 * serves to the number of bits in the bitmap.
110 */
111static inline int pcpu_chunk_map_bits(struct pcpu_chunk *chunk)
112{
113	return pcpu_nr_pages_to_map_bits(chunk->nr_pages);
114}
115
116/**
117 * pcpu_obj_full_size - helper to calculate size of each accounted object
118 * @size: size of area to allocate in bytes
119 *
120 * For each accounted object there is an extra space which is used to store
121 * obj_cgroup membership. Charge it too.
122 */
123static inline size_t pcpu_obj_full_size(size_t size)
124{
125	size_t extra_size = 0;
126
127#ifdef CONFIG_MEMCG_KMEM
128	extra_size += size / PCPU_MIN_ALLOC_SIZE * sizeof(struct obj_cgroup *);
129#endif
130
131	return size * num_possible_cpus() + extra_size;
132}
133
134#ifdef CONFIG_PERCPU_STATS
135
136#include <linux/spinlock.h>
137
138struct percpu_stats {
139	u64 nr_alloc;		/* lifetime # of allocations */
140	u64 nr_dealloc;		/* lifetime # of deallocations */
141	u64 nr_cur_alloc;	/* current # of allocations */
142	u64 nr_max_alloc;	/* max # of live allocations */
143	u32 nr_chunks;		/* current # of live chunks */
144	u32 nr_max_chunks;	/* max # of live chunks */
145	size_t min_alloc_size;	/* min allocation size */
146	size_t max_alloc_size;	/* max allocation size */
147};
148
149extern struct percpu_stats pcpu_stats;
150extern struct pcpu_alloc_info pcpu_stats_ai;
151
152/*
153 * For debug purposes. We don't care about the flexible array.
154 */
155static inline void pcpu_stats_save_ai(const struct pcpu_alloc_info *ai)
156{
157	memcpy(&pcpu_stats_ai, ai, sizeof(struct pcpu_alloc_info));
158
159	/* initialize min_alloc_size to unit_size */
160	pcpu_stats.min_alloc_size = pcpu_stats_ai.unit_size;
161}
162
163/*
164 * pcpu_stats_area_alloc - increment area allocation stats
165 * @chunk: the location of the area being allocated
166 * @size: size of area to allocate in bytes
167 *
168 * CONTEXT:
169 * pcpu_lock.
170 */
171static inline void pcpu_stats_area_alloc(struct pcpu_chunk *chunk, size_t size)
172{
173	lockdep_assert_held(&pcpu_lock);
174
175	pcpu_stats.nr_alloc++;
176	pcpu_stats.nr_cur_alloc++;
177	pcpu_stats.nr_max_alloc =
178		max(pcpu_stats.nr_max_alloc, pcpu_stats.nr_cur_alloc);
179	pcpu_stats.min_alloc_size =
180		min(pcpu_stats.min_alloc_size, size);
181	pcpu_stats.max_alloc_size =
182		max(pcpu_stats.max_alloc_size, size);
183
184	chunk->nr_alloc++;
185	chunk->max_alloc_size = max(chunk->max_alloc_size, size);
186}
187
188/*
189 * pcpu_stats_area_dealloc - decrement allocation stats
190 * @chunk: the location of the area being deallocated
191 *
192 * CONTEXT:
193 * pcpu_lock.
194 */
195static inline void pcpu_stats_area_dealloc(struct pcpu_chunk *chunk)
196{
197	lockdep_assert_held(&pcpu_lock);
198
199	pcpu_stats.nr_dealloc++;
200	pcpu_stats.nr_cur_alloc--;
201
202	chunk->nr_alloc--;
203}
204
205/*
206 * pcpu_stats_chunk_alloc - increment chunk stats
207 */
208static inline void pcpu_stats_chunk_alloc(void)
209{
210	unsigned long flags;
211	spin_lock_irqsave(&pcpu_lock, flags);
212
213	pcpu_stats.nr_chunks++;
214	pcpu_stats.nr_max_chunks =
215		max(pcpu_stats.nr_max_chunks, pcpu_stats.nr_chunks);
216
217	spin_unlock_irqrestore(&pcpu_lock, flags);
218}
219
220/*
221 * pcpu_stats_chunk_dealloc - decrement chunk stats
222 */
223static inline void pcpu_stats_chunk_dealloc(void)
224{
225	unsigned long flags;
226	spin_lock_irqsave(&pcpu_lock, flags);
227
228	pcpu_stats.nr_chunks--;
229
230	spin_unlock_irqrestore(&pcpu_lock, flags);
231}
232
233#else
234
235static inline void pcpu_stats_save_ai(const struct pcpu_alloc_info *ai)
236{
237}
238
239static inline void pcpu_stats_area_alloc(struct pcpu_chunk *chunk, size_t size)
240{
241}
242
243static inline void pcpu_stats_area_dealloc(struct pcpu_chunk *chunk)
244{
245}
246
247static inline void pcpu_stats_chunk_alloc(void)
248{
249}
250
251static inline void pcpu_stats_chunk_dealloc(void)
252{
253}
254
255#endif /* !CONFIG_PERCPU_STATS */
256
257#endif