pthread_md.h revision 133756 
1/*-
2 * Copyright (c) 2002 Daniel Eischen <deischen@freebsd.org>.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 *
26 * $FreeBSD: head/lib/libkse/arch/i386/include/pthread_md.h 133756 2004-08-15 16:28:05Z dfr $
27 */
28/*
29 * Machine-dependent thread prototypes/definitions for the thread kernel.
30 */
31#ifndef _PTHREAD_MD_H_
32#define	_PTHREAD_MD_H_
33
34#include <sys/kse.h>
35#include <ucontext.h>
36
37extern int _thr_setcontext(mcontext_t *, intptr_t, intptr_t *);
38extern int _thr_getcontext(mcontext_t *);
39
40#define	KSE_STACKSIZE		16384
41
42#define	THR_GETCONTEXT(ucp)	_thr_getcontext(&(ucp)->uc_mcontext)
43#define	THR_SETCONTEXT(ucp)	_thr_setcontext(&(ucp)->uc_mcontext, 0, NULL)
44
45#define	PER_KSE
46#undef	PER_THREAD
47
48struct kse;
49struct pthread;
50
51/*
52 * %gs points to a struct kcb.
53 */
54struct kcb {
55	struct tcb		*kcb_curtcb;
56	struct kcb		*kcb_self;	/* self reference */
57	int			kcb_ldt;
58	struct kse		*kcb_kse;
59	struct kse_mailbox	kcb_kmbx;
60};
61
62struct tcb {
63	struct tcb		*tcb_self;	/* required by rtld */
64	void			*tcb_dtv;	/* required by rtld */
65	struct pthread		*tcb_thread;
66	void			*tcb_spare;	/* align tcb_tmbx to 16 bytes */
67	struct kse_thr_mailbox	tcb_tmbx;
68};
69
70/*
71 * Evaluates to the byte offset of the per-kse variable name.
72 */
73#define	__kcb_offset(name)	__offsetof(struct kcb, name)
74
75/*
76 * Evaluates to the type of the per-kse variable name.
77 */
78#define	__kcb_type(name)	__typeof(((struct kcb *)0)->name)
79
80/*
81 * Evaluates to the value of the per-kse variable name.
82 */
83#define	KCB_GET32(name) ({					\
84	__kcb_type(name) __result;				\
85								\
86	u_int __i;						\
87	__asm __volatile("movl %%gs:%1, %0"			\
88	    : "=r" (__i)					\
89	    : "m" (*(u_int *)(__kcb_offset(name))));		\
90	__result = *(__kcb_type(name) *)&__i;			\
91								\
92	__result;						\
93})
94
95/*
96 * Sets the value of the per-kse variable name to value val.
97 */
98#define	KCB_SET32(name, val) ({					\
99	__kcb_type(name) __val = (val);				\
100								\
101	u_int __i;						\
102	__i = *(u_int *)&__val;					\
103	__asm __volatile("movl %1,%%gs:%0"			\
104	    : "=m" (*(u_int *)(__kcb_offset(name)))		\
105	    : "r" (__i));					\
106})
107
108static __inline u_long
109__kcb_readandclear32(volatile u_long *addr)
110{
111	u_long result;
112
113	__asm __volatile (
114	    "	xorl	%0, %0;"
115	    "	xchgl	%%gs:%1, %0;"
116	    "# __kcb_readandclear32"
117	    : "=&r" (result)
118	    : "m" (*addr));
119	return (result);
120}
121
122#define	KCB_READANDCLEAR32(name) ({				\
123	__kcb_type(name) __result;				\
124								\
125	__result = (__kcb_type(name))				\
126	    __kcb_readandclear32((u_long *)__kcb_offset(name)); \
127	__result;						\
128})
129
130
131#define	_kcb_curkcb()		KCB_GET32(kcb_self)
132#define	_kcb_curtcb()		KCB_GET32(kcb_curtcb)
133#define	_kcb_curkse()		((struct kse *)KCB_GET32(kcb_kmbx.km_udata))
134#define	_kcb_get_tmbx()		KCB_GET32(kcb_kmbx.km_curthread)
135#define	_kcb_set_tmbx(value)	KCB_SET32(kcb_kmbx.km_curthread, (void *)value)
136#define	_kcb_readandclear_tmbx() KCB_READANDCLEAR32(kcb_kmbx.km_curthread)
137
138
139/*
140 * The constructors.
141 */
142struct tcb	*_tcb_ctor(struct pthread *, int);
143void		_tcb_dtor(struct tcb *tcb);
144struct kcb	*_kcb_ctor(struct kse *);
145void		_kcb_dtor(struct kcb *);
146
147/* Called from the KSE to set its private data. */
148static __inline void
149_kcb_set(struct kcb *kcb)
150{
151	int val;
152
153	val = (kcb->kcb_ldt << 3) | 7;
154	__asm __volatile("movl %0, %%gs" : : "r" (val));
155}
156
157/* Get the current kcb. */
158static __inline struct kcb *
159_kcb_get(void)
160{
161	return (_kcb_curkcb());
162}
163
164static __inline struct kse_thr_mailbox *
165_kcb_critical_enter(void)
166{
167	struct kse_thr_mailbox *crit;
168
169	crit = _kcb_readandclear_tmbx();
170	return (crit);
171}
172
173static __inline void
174_kcb_critical_leave(struct kse_thr_mailbox *crit)
175{
176	_kcb_set_tmbx(crit);
177}
178
179static __inline int
180_kcb_in_critical(void)
181{
182	return (_kcb_get_tmbx() == NULL);
183}
184
185static __inline void
186_tcb_set(struct kcb *kcb, struct tcb *tcb)
187{
188	kcb->kcb_curtcb = tcb;
189}
190
191static __inline struct tcb *
192_tcb_get(void)
193{
194	return (_kcb_curtcb());
195}
196
197static __inline struct pthread *
198_get_curthread(void)
199{
200	struct tcb *tcb;
201
202	tcb = _kcb_curtcb();
203	if (tcb != NULL)
204		return (tcb->tcb_thread);
205	else
206		return (NULL);
207}
208
209static __inline struct kse *
210_get_curkse(void)
211{
212	return ((struct kse *)_kcb_curkse());
213}
214
215void	_i386_enter_uts(struct kse_mailbox *km, kse_func_t uts, void *stack,
216    size_t stacksz);
217
218static __inline int
219_thread_enter_uts(struct tcb *tcb, struct kcb *kcb)
220{
221	int ret;
222
223	ret = _thr_getcontext(&tcb->tcb_tmbx.tm_context.uc_mcontext);
224	if (ret == 0) {
225		_i386_enter_uts(&kcb->kcb_kmbx, kcb->kcb_kmbx.km_func,
226		    kcb->kcb_kmbx.km_stack.ss_sp,
227		    kcb->kcb_kmbx.km_stack.ss_size);
228		/* We should not reach here. */
229		return (-1);
230	}
231	else if (ret < 0)
232		return (-1);
233	return (0);
234}
235
236static __inline int
237_thread_switch(struct kcb *kcb, struct tcb *tcb, int setmbox)
238{
239	extern int _libkse_debug;
240
241	if ((kcb == NULL) || (tcb == NULL))
242		return (-1);
243	kcb->kcb_curtcb = tcb;
244	if (_libkse_debug == 0) {
245		tcb->tcb_tmbx.tm_lwp = kcb->kcb_kmbx.km_lwp;
246		if (setmbox != 0)
247			_thr_setcontext(&tcb->tcb_tmbx.tm_context.uc_mcontext,
248			    (intptr_t)&tcb->tcb_tmbx,
249			    (intptr_t *)&kcb->kcb_kmbx.km_curthread);
250		else
251			_thr_setcontext(&tcb->tcb_tmbx.tm_context.uc_mcontext,
252				0, NULL);
253	} else {
254		if (setmbox)
255			kse_switchin(&tcb->tcb_tmbx, KSE_SWITCHIN_SETTMBX);
256		else
257			kse_switchin(&tcb->tcb_tmbx, 0);
258	}
259
260	/* We should not reach here. */
261	return (-1);
262}
263
264#endif
265