xref: /freebsd/sys/sys/smp.h (revision 2f513db7)
1 /*-
2  * SPDX-License-Identifier: Beerware
3  *
4  * ----------------------------------------------------------------------------
5  * "THE BEER-WARE LICENSE" (Revision 42):
6  * <phk@FreeBSD.org> wrote this file.  As long as you retain this notice you
7  * can do whatever you want with this stuff. If we meet some day, and you think
8  * this stuff is worth it, you can buy me a beer in return.   Poul-Henning Kamp
9  * ----------------------------------------------------------------------------
10  *
11  * $FreeBSD$
12  */
13 
14 #ifndef _SYS_SMP_H_
15 #define _SYS_SMP_H_
16 
17 #ifdef _KERNEL
18 
19 #ifndef LOCORE
20 
21 #include <sys/cpuset.h>
22 #include <sys/queue.h>
23 
24 /*
25  * Types of nodes in the topological tree.
26  */
27 typedef enum {
28 	/* No node has this type; can be used in topo API calls. */
29 	TOPO_TYPE_DUMMY,
30 	/* Processing unit aka computing unit aka logical CPU. */
31 	TOPO_TYPE_PU,
32 	/* Physical subdivision of a package. */
33 	TOPO_TYPE_CORE,
34 	/* CPU L1/L2/L3 cache. */
35 	TOPO_TYPE_CACHE,
36 	/* Package aka chip, equivalent to socket. */
37 	TOPO_TYPE_PKG,
38 	/* NUMA node. */
39 	TOPO_TYPE_NODE,
40 	/* Other logical or physical grouping of PUs. */
41 	/* E.g. PUs on the same dye, or PUs sharing an FPU. */
42 	TOPO_TYPE_GROUP,
43 	/* The whole system. */
44 	TOPO_TYPE_SYSTEM
45 } topo_node_type;
46 
47 /* Hardware indenitifier of a topology component. */
48 typedef	unsigned int hwid_t;
49 /* Logical CPU idenitifier. */
50 typedef	int cpuid_t;
51 
52 /* A node in the topology. */
53 struct topo_node {
54 	struct topo_node			*parent;
55 	TAILQ_HEAD(topo_children, topo_node)	children;
56 	TAILQ_ENTRY(topo_node)			siblings;
57 	cpuset_t				cpuset;
58 	topo_node_type				type;
59 	uintptr_t				subtype;
60 	hwid_t					hwid;
61 	cpuid_t					id;
62 	int					nchildren;
63 	int					cpu_count;
64 };
65 
66 /*
67  * Scheduling topology of a NUMA or SMP system.
68  *
69  * The top level topology is an array of pointers to groups.  Each group
70  * contains a bitmask of cpus in its group or subgroups.  It may also
71  * contain a pointer to an array of child groups.
72  *
73  * The bitmasks at non leaf groups may be used by consumers who support
74  * a smaller depth than the hardware provides.
75  *
76  * The topology may be omitted by systems where all CPUs are equal.
77  */
78 
79 struct cpu_group {
80 	struct cpu_group *cg_parent;	/* Our parent group. */
81 	struct cpu_group *cg_child;	/* Optional children groups. */
82 	cpuset_t	cg_mask;	/* Mask of cpus in this group. */
83 	int32_t		cg_count;	/* Count of cpus in this group. */
84 	int16_t		cg_children;	/* Number of children groups. */
85 	int8_t		cg_level;	/* Shared cache level. */
86 	int8_t		cg_flags;	/* Traversal modifiers. */
87 };
88 
89 typedef struct cpu_group *cpu_group_t;
90 
91 /*
92  * Defines common resources for CPUs in the group.  The highest level
93  * resource should be used when multiple are shared.
94  */
95 #define	CG_SHARE_NONE	0
96 #define	CG_SHARE_L1	1
97 #define	CG_SHARE_L2	2
98 #define	CG_SHARE_L3	3
99 
100 #define MAX_CACHE_LEVELS	CG_SHARE_L3
101 
102 /*
103  * Behavior modifiers for load balancing and affinity.
104  */
105 #define	CG_FLAG_HTT	0x01		/* Schedule the alternate core last. */
106 #define	CG_FLAG_SMT	0x02		/* New age htt, less crippled. */
107 #define	CG_FLAG_THREAD	(CG_FLAG_HTT | CG_FLAG_SMT)	/* Any threading. */
108 
109 /*
110  * Convenience routines for building and traversing topologies.
111  */
112 #ifdef SMP
113 void topo_init_node(struct topo_node *node);
114 void topo_init_root(struct topo_node *root);
115 struct topo_node * topo_add_node_by_hwid(struct topo_node *parent, int hwid,
116     topo_node_type type, uintptr_t subtype);
117 struct topo_node * topo_find_node_by_hwid(struct topo_node *parent, int hwid,
118     topo_node_type type, uintptr_t subtype);
119 void topo_promote_child(struct topo_node *child);
120 struct topo_node * topo_next_node(struct topo_node *top,
121     struct topo_node *node);
122 struct topo_node * topo_next_nonchild_node(struct topo_node *top,
123     struct topo_node *node);
124 void topo_set_pu_id(struct topo_node *node, cpuid_t id);
125 
126 enum topo_level {
127 	TOPO_LEVEL_PKG = 0,
128 	/*
129 	 * Some systems have useful sub-package core organizations.  On these,
130 	 * a package has one or more subgroups.  Each subgroup contains one or
131 	 * more cache groups (cores that share a last level cache).
132 	 */
133 	TOPO_LEVEL_GROUP,
134 	TOPO_LEVEL_CACHEGROUP,
135 	TOPO_LEVEL_CORE,
136 	TOPO_LEVEL_THREAD,
137 	TOPO_LEVEL_COUNT	/* Must be last */
138 };
139 struct topo_analysis {
140 	int entities[TOPO_LEVEL_COUNT];
141 };
142 int topo_analyze(struct topo_node *topo_root, int all,
143     struct topo_analysis *results);
144 
145 #define	TOPO_FOREACH(i, root)	\
146 	for (i = root; i != NULL; i = topo_next_node(root, i))
147 
148 struct cpu_group *smp_topo(void);
149 struct cpu_group *smp_topo_alloc(u_int count);
150 struct cpu_group *smp_topo_none(void);
151 struct cpu_group *smp_topo_1level(int l1share, int l1count, int l1flags);
152 struct cpu_group *smp_topo_2level(int l2share, int l2count, int l1share,
153     int l1count, int l1flags);
154 struct cpu_group *smp_topo_find(struct cpu_group *top, int cpu);
155 
156 extern void (*cpustop_restartfunc)(void);
157 extern int smp_cpus;
158 /* The suspend/resume cpusets are x86 only, but minimize ifdefs. */
159 extern volatile cpuset_t resuming_cpus;	/* woken up cpus in suspend pen */
160 extern volatile cpuset_t started_cpus;	/* cpus to let out of stop pen */
161 extern volatile cpuset_t stopped_cpus;	/* cpus in stop pen */
162 extern volatile cpuset_t suspended_cpus; /* cpus [near] sleeping in susp pen */
163 extern volatile cpuset_t toresume_cpus;	/* cpus to let out of suspend pen */
164 extern cpuset_t hlt_cpus_mask;		/* XXX 'mask' is detail in old impl */
165 extern cpuset_t logical_cpus_mask;
166 #endif /* SMP */
167 
168 extern u_int mp_maxid;
169 extern int mp_maxcpus;
170 extern int mp_ncores;
171 extern int mp_ncpus;
172 extern volatile int smp_started;
173 extern int smp_threads_per_core;
174 
175 extern cpuset_t all_cpus;
176 extern cpuset_t cpuset_domain[MAXMEMDOM]; 	/* CPUs in each NUMA domain. */
177 
178 /*
179  * Macro allowing us to determine whether a CPU is absent at any given
180  * time, thus permitting us to configure sparse maps of cpuid-dependent
181  * (per-CPU) structures.
182  */
183 #define	CPU_ABSENT(x_cpu)	(!CPU_ISSET(x_cpu, &all_cpus))
184 
185 /*
186  * Macros to iterate over non-absent CPUs.  CPU_FOREACH() takes an
187  * integer iterator and iterates over the available set of CPUs.
188  * CPU_FIRST() returns the id of the first non-absent CPU.  CPU_NEXT()
189  * returns the id of the next non-absent CPU.  It will wrap back to
190  * CPU_FIRST() once the end of the list is reached.  The iterators are
191  * currently implemented via inline functions.
192  */
193 #define	CPU_FOREACH(i)							\
194 	for ((i) = 0; (i) <= mp_maxid; (i)++)				\
195 		if (!CPU_ABSENT((i)))
196 
197 static __inline int
198 cpu_first(void)
199 {
200 	int i;
201 
202 	for (i = 0;; i++)
203 		if (!CPU_ABSENT(i))
204 			return (i);
205 }
206 
207 static __inline int
208 cpu_next(int i)
209 {
210 
211 	for (;;) {
212 		i++;
213 		if (i > mp_maxid)
214 			i = 0;
215 		if (!CPU_ABSENT(i))
216 			return (i);
217 	}
218 }
219 
220 #define	CPU_FIRST()	cpu_first()
221 #define	CPU_NEXT(i)	cpu_next((i))
222 
223 #ifdef SMP
224 /*
225  * Machine dependent functions used to initialize MP support.
226  *
227  * The cpu_mp_probe() should check to see if MP support is present and return
228  * zero if it is not or non-zero if it is.  If MP support is present, then
229  * cpu_mp_start() will be called so that MP can be enabled.  This function
230  * should do things such as startup secondary processors.  It should also
231  * setup mp_ncpus, all_cpus, and smp_cpus.  It should also ensure that
232  * smp_started is initialized at the appropriate time.
233  * Once cpu_mp_start() returns, machine independent MP startup code will be
234  * executed and a simple message will be output to the console.  Finally,
235  * cpu_mp_announce() will be called so that machine dependent messages about
236  * the MP support may be output to the console if desired.
237  *
238  * The cpu_setmaxid() function is called very early during the boot process
239  * so that the MD code may set mp_maxid to provide an upper bound on CPU IDs
240  * that other subsystems may use.  If a platform is not able to determine
241  * the exact maximum ID that early, then it may set mp_maxid to MAXCPU - 1.
242  */
243 struct thread;
244 
245 struct cpu_group *cpu_topo(void);
246 void	cpu_mp_announce(void);
247 int	cpu_mp_probe(void);
248 void	cpu_mp_setmaxid(void);
249 void	cpu_mp_start(void);
250 
251 void	forward_signal(struct thread *);
252 int	restart_cpus(cpuset_t);
253 int	stop_cpus(cpuset_t);
254 int	stop_cpus_hard(cpuset_t);
255 #if defined(__amd64__) || defined(__i386__)
256 int	suspend_cpus(cpuset_t);
257 int	resume_cpus(cpuset_t);
258 #endif
259 
260 void	smp_rendezvous_action(void);
261 extern	struct mtx smp_ipi_mtx;
262 
263 #endif /* SMP */
264 
265 int	quiesce_all_cpus(const char *, int);
266 int	quiesce_cpus(cpuset_t, const char *, int);
267 void	quiesce_all_critical(void);
268 void	cpus_fence_seq_cst(void);
269 void	smp_no_rendezvous_barrier(void *);
270 void	smp_rendezvous(void (*)(void *),
271 		       void (*)(void *),
272 		       void (*)(void *),
273 		       void *arg);
274 void	smp_rendezvous_cpus(cpuset_t,
275 		       void (*)(void *),
276 		       void (*)(void *),
277 		       void (*)(void *),
278 		       void *arg);
279 
280 struct smp_rendezvous_cpus_retry_arg {
281 	cpuset_t cpus;
282 };
283 void	smp_rendezvous_cpus_retry(cpuset_t,
284 		       void (*)(void *),
285 		       void (*)(void *),
286 		       void (*)(void *),
287 		       void (*)(void *, int),
288 		       struct smp_rendezvous_cpus_retry_arg *);
289 
290 void	smp_rendezvous_cpus_done(struct smp_rendezvous_cpus_retry_arg *);
291 
292 #endif /* !LOCORE */
293 #endif /* _KERNEL */
294 #endif /* _SYS_SMP_H_ */
295