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#include <linux/memcontrol.h>
  8
  9/*
 10 * pcpu_block_md is the metadata block struct.
 11 * Each chunk's bitmap is split into a number of full blocks.
 12 * All units are in terms of bits.
 13 *
 14 * The scan hint is the largest known contiguous area before the contig hint.
 15 * It is not necessarily the actual largest contig hint though.  There is an
 16 * invariant that the scan_hint_start > contig_hint_start iff
 17 * scan_hint == contig_hint.  This is necessary because when scanning forward,
 18 * we don't know if a new contig hint would be better than the current one.
 19 */
 20struct pcpu_block_md {
 21	int			scan_hint;	/* scan hint for block */
 22	int			scan_hint_start; /* block relative starting
 23						    position of the scan hint */
 24	int                     contig_hint;    /* contig hint for block */
 25	int                     contig_hint_start; /* block relative starting
 26						      position of the contig hint */
 27	int                     left_free;      /* size of free space along
 28						   the left side of the block */
 29	int                     right_free;     /* size of free space along
 30						   the right side of the block */
 31	int                     first_free;     /* block position of first free */
 32	int			nr_bits;	/* total bits responsible for */
 33};
 34
 35struct pcpuobj_ext {
 36#ifdef CONFIG_MEMCG
 37	struct obj_cgroup	*cgroup;
 38#endif
 39#ifdef CONFIG_MEM_ALLOC_PROFILING
 40	union codetag_ref	tag;
 41#endif
 42};
 43
 44#if defined(CONFIG_MEMCG) || defined(CONFIG_MEM_ALLOC_PROFILING)
 45#define NEED_PCPUOBJ_EXT
 46#endif
 47
 48struct pcpu_chunk {
 49#ifdef CONFIG_PERCPU_STATS
 50	int			nr_alloc;	/* # of allocations */
 51	size_t			max_alloc_size; /* largest allocation size */
 52#endif
 53
 54	struct list_head	list;		/* linked to pcpu_slot lists */
 55	int			free_bytes;	/* free bytes in the chunk */
 56	struct pcpu_block_md	chunk_md;
 57	unsigned long		*bound_map;	/* boundary map */
 58
 59	/*
 60	 * base_addr is the base address of this chunk.
 61	 * To reduce false sharing, current layout is optimized to make sure
 62	 * base_addr locate in the different cacheline with free_bytes and
 63	 * chunk_md.
 64	 */
 65	void			*base_addr ____cacheline_aligned_in_smp;
 66
 67	unsigned long		*alloc_map;	/* allocation map */
 68	struct pcpu_block_md	*md_blocks;	/* metadata blocks */
 69
 70	void			*data;		/* chunk data */
 71	bool			immutable;	/* no [de]population allowed */
 72	bool			isolated;	/* isolated from active chunk
 73						   slots */
 74	int			start_offset;	/* the overlap with the previous
 75						   region to have a page aligned
 76						   base_addr */
 77	int			end_offset;	/* additional area required to
 78						   have the region end page
 79						   aligned */
 80#ifdef NEED_PCPUOBJ_EXT
 81	struct pcpuobj_ext	*obj_exts;	/* vector of object cgroups */
 82#endif
 83
 84	int			nr_pages;	/* # of pages served by this chunk */
 85	int			nr_populated;	/* # of populated pages */
 86	int                     nr_empty_pop_pages; /* # of empty populated pages */
 87	unsigned long		populated[];	/* populated bitmap */
 88};
 89
 90static inline bool need_pcpuobj_ext(void)
 91{
 92	if (IS_ENABLED(CONFIG_MEM_ALLOC_PROFILING))
 93		return true;
 94	if (!mem_cgroup_kmem_disabled())
 95		return true;
 96	return false;
 97}
 98
 99extern spinlock_t pcpu_lock;
100
101extern struct list_head *pcpu_chunk_lists;
102extern int pcpu_nr_slots;
103extern int pcpu_sidelined_slot;
104extern int pcpu_to_depopulate_slot;
105extern int pcpu_nr_empty_pop_pages;
106
107extern struct pcpu_chunk *pcpu_first_chunk;
108extern struct pcpu_chunk *pcpu_reserved_chunk;
109
110/**
111 * pcpu_chunk_nr_blocks - converts nr_pages to # of md_blocks
112 * @chunk: chunk of interest
113 *
114 * This conversion is from the number of physical pages that the chunk
115 * serves to the number of bitmap blocks used.
116 */
117static inline int pcpu_chunk_nr_blocks(struct pcpu_chunk *chunk)
118{
119	return chunk->nr_pages * PAGE_SIZE / PCPU_BITMAP_BLOCK_SIZE;
120}
121
122/**
123 * pcpu_nr_pages_to_map_bits - converts the pages to size of bitmap
124 * @pages: number of physical pages
125 *
126 * This conversion is from physical pages to the number of bits
127 * required in the bitmap.
128 */
129static inline int pcpu_nr_pages_to_map_bits(int pages)
130{
131	return pages * PAGE_SIZE / PCPU_MIN_ALLOC_SIZE;
132}
133
134/**
135 * pcpu_chunk_map_bits - helper to convert nr_pages to size of bitmap
136 * @chunk: chunk of interest
137 *
138 * This conversion is from the number of physical pages that the chunk
139 * serves to the number of bits in the bitmap.
140 */
141static inline int pcpu_chunk_map_bits(struct pcpu_chunk *chunk)
142{
143	return pcpu_nr_pages_to_map_bits(chunk->nr_pages);
144}
145
146/**
147 * pcpu_obj_full_size - helper to calculate size of each accounted object
148 * @size: size of area to allocate in bytes
149 *
150 * For each accounted object there is an extra space which is used to store
151 * obj_cgroup membership if kmemcg is not disabled. Charge it too.
152 */
153static inline size_t pcpu_obj_full_size(size_t size)
154{
155	size_t extra_size = 0;
156
157#ifdef CONFIG_MEMCG
158	if (!mem_cgroup_kmem_disabled())
159		extra_size += size / PCPU_MIN_ALLOC_SIZE * sizeof(struct obj_cgroup *);
160#endif
161
162	return size * num_possible_cpus() + extra_size;
163}
164
165#ifdef CONFIG_PERCPU_STATS
166
167#include <linux/spinlock.h>
168
169struct percpu_stats {
170	u64 nr_alloc;		/* lifetime # of allocations */
171	u64 nr_dealloc;		/* lifetime # of deallocations */
172	u64 nr_cur_alloc;	/* current # of allocations */
173	u64 nr_max_alloc;	/* max # of live allocations */
174	u32 nr_chunks;		/* current # of live chunks */
175	u32 nr_max_chunks;	/* max # of live chunks */
176	size_t min_alloc_size;	/* min allocation size */
177	size_t max_alloc_size;	/* max allocation size */
178};
179
180extern struct percpu_stats pcpu_stats;
181extern struct pcpu_alloc_info pcpu_stats_ai;
182
183/*
184 * For debug purposes. We don't care about the flexible array.
185 */
186static inline void pcpu_stats_save_ai(const struct pcpu_alloc_info *ai)
187{
188	memcpy(&pcpu_stats_ai, ai, sizeof(struct pcpu_alloc_info));
189
190	/* initialize min_alloc_size to unit_size */
191	pcpu_stats.min_alloc_size = pcpu_stats_ai.unit_size;
192}
193
194/*
195 * pcpu_stats_area_alloc - increment area allocation stats
196 * @chunk: the location of the area being allocated
197 * @size: size of area to allocate in bytes
198 *
199 * CONTEXT:
200 * pcpu_lock.
201 */
202static inline void pcpu_stats_area_alloc(struct pcpu_chunk *chunk, size_t size)
203{
204	lockdep_assert_held(&pcpu_lock);
205
206	pcpu_stats.nr_alloc++;
207	pcpu_stats.nr_cur_alloc++;
208	pcpu_stats.nr_max_alloc =
209		max(pcpu_stats.nr_max_alloc, pcpu_stats.nr_cur_alloc);
210	pcpu_stats.min_alloc_size =
211		min(pcpu_stats.min_alloc_size, size);
212	pcpu_stats.max_alloc_size =
213		max(pcpu_stats.max_alloc_size, size);
214
215	chunk->nr_alloc++;
216	chunk->max_alloc_size = max(chunk->max_alloc_size, size);
217}
218
219/*
220 * pcpu_stats_area_dealloc - decrement allocation stats
221 * @chunk: the location of the area being deallocated
222 *
223 * CONTEXT:
224 * pcpu_lock.
225 */
226static inline void pcpu_stats_area_dealloc(struct pcpu_chunk *chunk)
227{
228	lockdep_assert_held(&pcpu_lock);
229
230	pcpu_stats.nr_dealloc++;
231	pcpu_stats.nr_cur_alloc--;
232
233	chunk->nr_alloc--;
234}
235
236/*
237 * pcpu_stats_chunk_alloc - increment chunk stats
238 */
239static inline void pcpu_stats_chunk_alloc(void)
240{
241	unsigned long flags;
242	spin_lock_irqsave(&pcpu_lock, flags);
243
244	pcpu_stats.nr_chunks++;
245	pcpu_stats.nr_max_chunks =
246		max(pcpu_stats.nr_max_chunks, pcpu_stats.nr_chunks);
247
248	spin_unlock_irqrestore(&pcpu_lock, flags);
249}
250
251/*
252 * pcpu_stats_chunk_dealloc - decrement chunk stats
253 */
254static inline void pcpu_stats_chunk_dealloc(void)
255{
256	unsigned long flags;
257	spin_lock_irqsave(&pcpu_lock, flags);
258
259	pcpu_stats.nr_chunks--;
260
261	spin_unlock_irqrestore(&pcpu_lock, flags);
262}
263
264#else
265
266static inline void pcpu_stats_save_ai(const struct pcpu_alloc_info *ai)
267{
268}
269
270static inline void pcpu_stats_area_alloc(struct pcpu_chunk *chunk, size_t size)
271{
272}
273
274static inline void pcpu_stats_area_dealloc(struct pcpu_chunk *chunk)
275{
276}
277
278static inline void pcpu_stats_chunk_alloc(void)
279{
280}
281
282static inline void pcpu_stats_chunk_dealloc(void)
283{
284}
285
286#endif /* !CONFIG_PERCPU_STATS */
287
288#endif