pthread_md.h revision 134326 
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 134326 2004-08-26 02:41:01Z davidxu $
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 <stddef.h>
35#include <sys/kse.h>
36#include <ucontext.h>
37
38extern int _thr_setcontext(mcontext_t *, intptr_t, intptr_t *);
39extern int _thr_getcontext(mcontext_t *);
40
41#define	KSE_STACKSIZE		16384
42#define	DTV_OFFSET		offsetof(struct tcb, tcb_dtv)
43
44#define	THR_GETCONTEXT(ucp)	_thr_getcontext(&(ucp)->uc_mcontext)
45#define	THR_SETCONTEXT(ucp)	_thr_setcontext(&(ucp)->uc_mcontext, 0, NULL)
46
47#define	PER_KSE
48#undef	PER_THREAD
49
50struct kse;
51struct pthread;
52
53/*
54 * %gs points to a struct kcb.
55 */
56struct kcb {
57	struct tcb		*kcb_curtcb;
58	struct kcb		*kcb_self;	/* self reference */
59	int			kcb_ldt;
60	struct kse		*kcb_kse;
61	struct kse_mailbox	kcb_kmbx;
62};
63
64struct tcb {
65	struct tcb		*tcb_self;	/* required by rtld */
66	void			*tcb_dtv;	/* required by rtld */
67	struct pthread		*tcb_thread;
68	void			*tcb_spare;	/* align tcb_tmbx to 16 bytes */
69	struct kse_thr_mailbox	tcb_tmbx;
70};
71
72/*
73 * Evaluates to the byte offset of the per-kse variable name.
74 */
75#define	__kcb_offset(name)	__offsetof(struct kcb, name)
76
77/*
78 * Evaluates to the type of the per-kse variable name.
79 */
80#define	__kcb_type(name)	__typeof(((struct kcb *)0)->name)
81
82/*
83 * Evaluates to the value of the per-kse variable name.
84 */
85#define	KCB_GET32(name) ({					\
86	__kcb_type(name) __result;				\
87								\
88	u_int __i;						\
89	__asm __volatile("movl %%gs:%1, %0"			\
90	    : "=r" (__i)					\
91	    : "m" (*(u_int *)(__kcb_offset(name))));		\
92	__result = (__kcb_type(name))__i;			\
93								\
94	__result;						\
95})
96
97/*
98 * Sets the value of the per-kse variable name to value val.
99 */
100#define	KCB_SET32(name, val) ({					\
101	__kcb_type(name) __val = (val);				\
102								\
103	u_int __i;						\
104	__i = (u_int)__val;					\
105	__asm __volatile("movl %1,%%gs:%0"			\
106	    : "=m" (*(u_int *)(__kcb_offset(name)))		\
107	    : "r" (__i));					\
108})
109
110static __inline u_long
111__kcb_readandclear32(volatile u_long *addr)
112{
113	u_long result;
114
115	__asm __volatile (
116	    "	xorl	%0, %0;"
117	    "	xchgl	%%gs:%1, %0;"
118	    "# __kcb_readandclear32"
119	    : "=&r" (result)
120	    : "m" (*addr));
121	return (result);
122}
123
124#define	KCB_READANDCLEAR32(name) ({				\
125	__kcb_type(name) __result;				\
126								\
127	__result = (__kcb_type(name))				\
128	    __kcb_readandclear32((u_long *)__kcb_offset(name)); \
129	__result;						\
130})
131
132
133#define	_kcb_curkcb()		KCB_GET32(kcb_self)
134#define	_kcb_curtcb()		KCB_GET32(kcb_curtcb)
135#define	_kcb_curkse()		((struct kse *)KCB_GET32(kcb_kmbx.km_udata))
136#define	_kcb_get_tmbx()		KCB_GET32(kcb_kmbx.km_curthread)
137#define	_kcb_set_tmbx(value)	KCB_SET32(kcb_kmbx.km_curthread, (void *)value)
138#define	_kcb_readandclear_tmbx() KCB_READANDCLEAR32(kcb_kmbx.km_curthread)
139
140
141/*
142 * The constructors.
143 */
144struct tcb	*_tcb_ctor(struct pthread *, int);
145void		_tcb_dtor(struct tcb *tcb);
146struct kcb	*_kcb_ctor(struct kse *);
147void		_kcb_dtor(struct kcb *);
148
149/* Called from the KSE to set its private data. */
150static __inline void
151_kcb_set(struct kcb *kcb)
152{
153	int val;
154
155	val = (kcb->kcb_ldt << 3) | 7;
156	__asm __volatile("movl %0, %%gs" : : "r" (val));
157}
158
159/* Get the current kcb. */
160static __inline struct kcb *
161_kcb_get(void)
162{
163	return (_kcb_curkcb());
164}
165
166static __inline struct kse_thr_mailbox *
167_kcb_critical_enter(void)
168{
169	struct kse_thr_mailbox *crit;
170
171	crit = _kcb_readandclear_tmbx();
172	return (crit);
173}
174
175static __inline void
176_kcb_critical_leave(struct kse_thr_mailbox *crit)
177{
178	_kcb_set_tmbx(crit);
179}
180
181static __inline int
182_kcb_in_critical(void)
183{
184	return (_kcb_get_tmbx() == NULL);
185}
186
187static __inline void
188_tcb_set(struct kcb *kcb, struct tcb *tcb)
189{
190	kcb->kcb_curtcb = tcb;
191}
192
193static __inline struct tcb *
194_tcb_get(void)
195{
196	return (_kcb_curtcb());
197}
198
199static __inline struct pthread *
200_get_curthread(void)
201{
202	struct tcb *tcb;
203
204	tcb = _kcb_curtcb();
205	if (tcb != NULL)
206		return (tcb->tcb_thread);
207	else
208		return (NULL);
209}
210
211static __inline struct kse *
212_get_curkse(void)
213{
214	return ((struct kse *)_kcb_curkse());
215}
216
217void	_i386_enter_uts(struct kse_mailbox *km, kse_func_t uts, void *stack,
218    size_t stacksz);
219
220static __inline int
221_thread_enter_uts(struct tcb *tcb, struct kcb *kcb)
222{
223	int ret;
224
225	ret = _thr_getcontext(&tcb->tcb_tmbx.tm_context.uc_mcontext);
226	if (ret == 0) {
227		_i386_enter_uts(&kcb->kcb_kmbx, kcb->kcb_kmbx.km_func,
228		    kcb->kcb_kmbx.km_stack.ss_sp,
229		    kcb->kcb_kmbx.km_stack.ss_size);
230		/* We should not reach here. */
231		return (-1);
232	}
233	else if (ret < 0)
234		return (-1);
235	return (0);
236}
237
238static __inline int
239_thread_switch(struct kcb *kcb, struct tcb *tcb, int setmbox)
240{
241	extern int _libkse_debug;
242
243	if ((kcb == NULL) || (tcb == NULL))
244		return (-1);
245	kcb->kcb_curtcb = tcb;
246	if (_libkse_debug == 0) {
247		tcb->tcb_tmbx.tm_lwp = kcb->kcb_kmbx.km_lwp;
248		if (setmbox != 0)
249			_thr_setcontext(&tcb->tcb_tmbx.tm_context.uc_mcontext,
250			    (intptr_t)&tcb->tcb_tmbx,
251			    (intptr_t *)&kcb->kcb_kmbx.km_curthread);
252		else
253			_thr_setcontext(&tcb->tcb_tmbx.tm_context.uc_mcontext,
254				0, NULL);
255	} else {
256		if (setmbox)
257			kse_switchin(&tcb->tcb_tmbx, KSE_SWITCHIN_SETTMBX);
258		else
259			kse_switchin(&tcb->tcb_tmbx, 0);
260	}
261
262	/* We should not reach here. */
263	return (-1);
264}
265
266#endif
267