smp.h revision 331910 
1/*-
2 * ----------------------------------------------------------------------------
3 * "THE BEER-WARE LICENSE" (Revision 42):
4 * <phk@FreeBSD.org> wrote this file.  As long as you retain this notice you
5 * can do whatever you want with this stuff. If we meet some day, and you think
6 * this stuff is worth it, you can buy me a beer in return.   Poul-Henning Kamp
7 * ----------------------------------------------------------------------------
8 *
9 * $FreeBSD: stable/10/sys/sys/smp.h 331910 2018-04-03 07:52:06Z avg $
10 */
11
12#ifndef _SYS_SMP_H_
13#define _SYS_SMP_H_
14
15#ifdef _KERNEL
16
17#ifndef LOCORE
18
19#include <sys/cpuset.h>
20
21/*
22 * Topology of a NUMA or HTT system.
23 *
24 * The top level topology is an array of pointers to groups.  Each group
25 * contains a bitmask of cpus in its group or subgroups.  It may also
26 * contain a pointer to an array of child groups.
27 *
28 * The bitmasks at non leaf groups may be used by consumers who support
29 * a smaller depth than the hardware provides.
30 *
31 * The topology may be omitted by systems where all CPUs are equal.
32 */
33
34struct cpu_group {
35	struct cpu_group *cg_parent;	/* Our parent group. */
36	struct cpu_group *cg_child;	/* Optional children groups. */
37	cpuset_t	cg_mask;	/* Mask of cpus in this group. */
38	int32_t		cg_count;	/* Count of cpus in this group. */
39	int16_t		cg_children;	/* Number of children groups. */
40	int8_t		cg_level;	/* Shared cache level. */
41	int8_t		cg_flags;	/* Traversal modifiers. */
42};
43
44typedef struct cpu_group *cpu_group_t;
45
46/*
47 * Defines common resources for CPUs in the group.  The highest level
48 * resource should be used when multiple are shared.
49 */
50#define	CG_SHARE_NONE	0
51#define	CG_SHARE_L1	1
52#define	CG_SHARE_L2	2
53#define	CG_SHARE_L3	3
54
55/*
56 * Behavior modifiers for load balancing and affinity.
57 */
58#define	CG_FLAG_HTT	0x01		/* Schedule the alternate core last. */
59#define	CG_FLAG_SMT	0x02		/* New age htt, less crippled. */
60#define	CG_FLAG_THREAD	(CG_FLAG_HTT | CG_FLAG_SMT)	/* Any threading. */
61
62/*
63 * Convenience routines for building topologies.
64 */
65#ifdef SMP
66struct cpu_group *smp_topo(void);
67struct cpu_group *smp_topo_none(void);
68struct cpu_group *smp_topo_1level(int l1share, int l1count, int l1flags);
69struct cpu_group *smp_topo_2level(int l2share, int l2count, int l1share,
70    int l1count, int l1flags);
71struct cpu_group *smp_topo_find(struct cpu_group *top, int cpu);
72
73extern void (*cpustop_restartfunc)(void);
74extern int smp_cpus;
75/* The suspend/resume cpusets are x86 only, but minimize ifdefs. */
76extern volatile cpuset_t resuming_cpus;	/* woken up cpus in suspend pen */
77extern volatile cpuset_t started_cpus;	/* cpus to let out of stop pen */
78extern volatile cpuset_t stopped_cpus;	/* cpus in stop pen */
79extern volatile cpuset_t suspended_cpus; /* cpus [near] sleeping in susp pen */
80extern volatile cpuset_t toresume_cpus;	/* cpus to let out of suspend pen */
81extern cpuset_t hlt_cpus_mask;		/* XXX 'mask' is detail in old impl */
82extern cpuset_t logical_cpus_mask;
83#endif /* SMP */
84
85extern u_int mp_maxid;
86extern int mp_maxcpus;
87extern int mp_ncpus;
88extern volatile int smp_started;
89
90extern cpuset_t all_cpus;
91
92/*
93 * Macro allowing us to determine whether a CPU is absent at any given
94 * time, thus permitting us to configure sparse maps of cpuid-dependent
95 * (per-CPU) structures.
96 */
97#define	CPU_ABSENT(x_cpu)	(!CPU_ISSET(x_cpu, &all_cpus))
98
99/*
100 * Macros to iterate over non-absent CPUs.  CPU_FOREACH() takes an
101 * integer iterator and iterates over the available set of CPUs.
102 * CPU_FIRST() returns the id of the first non-absent CPU.  CPU_NEXT()
103 * returns the id of the next non-absent CPU.  It will wrap back to
104 * CPU_FIRST() once the end of the list is reached.  The iterators are
105 * currently implemented via inline functions.
106 */
107#define	CPU_FOREACH(i)							\
108	for ((i) = 0; (i) <= mp_maxid; (i)++)				\
109		if (!CPU_ABSENT((i)))
110
111static __inline int
112cpu_first(void)
113{
114	int i;
115
116	for (i = 0;; i++)
117		if (!CPU_ABSENT(i))
118			return (i);
119}
120
121static __inline int
122cpu_next(int i)
123{
124
125	for (;;) {
126		i++;
127		if (i > mp_maxid)
128			i = 0;
129		if (!CPU_ABSENT(i))
130			return (i);
131	}
132}
133
134#define	CPU_FIRST()	cpu_first()
135#define	CPU_NEXT(i)	cpu_next((i))
136
137#ifdef SMP
138/*
139 * Machine dependent functions used to initialize MP support.
140 *
141 * The cpu_mp_probe() should check to see if MP support is present and return
142 * zero if it is not or non-zero if it is.  If MP support is present, then
143 * cpu_mp_start() will be called so that MP can be enabled.  This function
144 * should do things such as startup secondary processors.  It should also
145 * setup mp_ncpus, all_cpus, and smp_cpus.  It should also ensure that
146 * smp_started is initialized at the appropriate time.
147 * Once cpu_mp_start() returns, machine independent MP startup code will be
148 * executed and a simple message will be output to the console.  Finally,
149 * cpu_mp_announce() will be called so that machine dependent messages about
150 * the MP support may be output to the console if desired.
151 *
152 * The cpu_setmaxid() function is called very early during the boot process
153 * so that the MD code may set mp_maxid to provide an upper bound on CPU IDs
154 * that other subsystems may use.  If a platform is not able to determine
155 * the exact maximum ID that early, then it may set mp_maxid to MAXCPU - 1.
156 */
157struct thread;
158
159struct cpu_group *cpu_topo(void);
160void	cpu_mp_announce(void);
161int	cpu_mp_probe(void);
162void	cpu_mp_setmaxid(void);
163void	cpu_mp_start(void);
164
165void	forward_signal(struct thread *);
166int	restart_cpus(cpuset_t);
167int	stop_cpus(cpuset_t);
168int	stop_cpus_hard(cpuset_t);
169#if defined(__amd64__) || defined(__i386__)
170int	suspend_cpus(cpuset_t);
171int	resume_cpus(cpuset_t);
172#endif
173
174void	smp_rendezvous_action(void);
175extern	struct mtx smp_ipi_mtx;
176
177#endif /* SMP */
178
179int	quiesce_all_cpus(const char *, int);
180int	quiesce_cpus(cpuset_t, const char *, int);
181void	smp_no_rendevous_barrier(void *);
182void	smp_rendezvous(void (*)(void *),
183		       void (*)(void *),
184		       void (*)(void *),
185		       void *arg);
186void	smp_rendezvous_cpus(cpuset_t,
187		       void (*)(void *),
188		       void (*)(void *),
189		       void (*)(void *),
190		       void *arg);
191#endif /* !LOCORE */
192#endif /* _KERNEL */
193#endif /* _SYS_SMP_H_ */
194