pthread_md.h revision 132400 
1/*
2 * Copyright 2004 by Peter Grehan. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 *    notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 *    notice, this list of conditions and the following disclaimer in the
11 *    documentation and/or other materials provided with the distribution.
12 * 3. The name of the author may not be used to endorse or promote products
13 *    derived from this software without specific prior written permission.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
20 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
21 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
22 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
23 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 *
27 * $FreeBSD: head/lib/libkse/arch/powerpc/include/pthread_md.h 132400 2004-07-19 12:19:04Z grehan $
28 */
29
30/*
31 * Machine-dependent thread prototypes/definitions for the thread kernel.
32 */
33#ifndef _PTHREAD_MD_H_
34#define	_PTHREAD_MD_H_
35
36#include <sys/kse.h>
37#include <stddef.h>
38#include <ucontext.h>
39
40extern void _ppc32_enter_uts(struct kse_mailbox *, kse_func_t, void *, size_t);
41extern int  _ppc32_setcontext(mcontext_t *, intptr_t, intptr_t *);
42extern int  _ppc32_getcontext(mcontext_t *);
43
44#define	KSE_STACKSIZE		16384
45
46#define	THR_GETCONTEXT(ucp)	_ppc32_getcontext(&(ucp)->uc_mcontext)
47#define	THR_SETCONTEXT(ucp)	_ppc32_setcontext(&(ucp)->uc_mcontext, 0, NULL)
48
49#define	PER_THREAD
50
51struct kcb;
52struct kse;
53struct pthread;
54struct tcb;
55struct tdv;
56
57/*
58 * %r2 points to a struct kcb.
59 */
60struct ppc32_tp {
61	struct tdv	*tp_tdv;	/* dynamic TLS */
62	uint32_t	_reserved_;
63	long double	tp_tls[0];	/* static TLS */
64};
65
66struct tcb {
67	struct kse_thr_mailbox	tcb_tmbx;
68	struct pthread		*tcb_thread;
69	struct kcb		*tcb_curkcb;
70	long			tcb_isfake;
71	struct ppc32_tp		tcb_tp;
72};
73
74struct kcb {
75	struct kse_mailbox	kcb_kmbx;
76	struct tcb		kcb_faketcb;
77	struct tcb		*kcb_curtcb;
78	struct kse		*kcb_kse;
79};
80
81/*
82 * From the PowerPC32 TLS spec:
83 *
84 * "r2 is the thread pointer, and points 0x7000 past the end of the
85 * thread control block." Or, 0x7008 past the start of the 8-byte tcb
86 */
87#define TP_OFFSET	0x7008
88register uint8_t *_tpr __asm("%r2");
89
90#define _tcb  ((struct tcb *)(_tpr - TP_OFFSET - offsetof(struct tcb, tcb_tp)))
91
92/*
93 * The kcb and tcb constructors.
94 */
95struct tcb	*_tcb_ctor(struct pthread *);
96void		_tcb_dtor(struct tcb *);
97struct kcb	*_kcb_ctor(struct kse *kse);
98void		_kcb_dtor(struct kcb *);
99
100/* Called from the KSE to set its private data. */
101static __inline void
102_kcb_set(struct kcb *kcb)
103{
104	/* There is no thread yet; use the fake tcb. */
105	_tpr = (uint8_t *)&kcb->kcb_faketcb.tcb_tp + TP_OFFSET;
106}
107
108/*
109 * Get the current kcb.
110 *
111 * This can only be called while in a critical region; don't
112 * worry about having the kcb changed out from under us.
113 */
114static __inline struct kcb *
115_kcb_get(void)
116{
117	return (_tcb->tcb_curkcb);
118}
119
120/*
121 * Enter a critical region.
122 *
123 * Read and clear km_curthread in the kse mailbox.
124 */
125static __inline struct kse_thr_mailbox *
126_kcb_critical_enter(void)
127{
128	struct kse_thr_mailbox *crit;
129	uint32_t flags;
130
131	if (_tcb->tcb_isfake != 0) {
132		/*
133		 * We already are in a critical region since
134		 * there is no current thread.
135		 */
136		crit = NULL;
137	} else {
138		flags = _tcb->tcb_tmbx.tm_flags;
139		_tcb->tcb_tmbx.tm_flags |= TMF_NOUPCALL;
140		crit = _tcb->tcb_curkcb->kcb_kmbx.km_curthread;
141		_tcb->tcb_curkcb->kcb_kmbx.km_curthread = NULL;
142		_tcb->tcb_tmbx.tm_flags = flags;
143	}
144	return (crit);
145}
146
147static __inline void
148_kcb_critical_leave(struct kse_thr_mailbox *crit)
149{
150        /* No need to do anything if this is a fake tcb. */
151        if (_tcb->tcb_isfake == 0)
152                _tcb->tcb_curkcb->kcb_kmbx.km_curthread = crit;
153}
154
155static __inline int
156_kcb_in_critical(void)
157{
158	uint32_t flags;
159	int ret;
160
161	if (_tcb->tcb_isfake != 0) {
162		/*
163		 * We are in a critical region since there is no
164		 * current thread.
165		 */
166		ret = 1;
167	} else {
168		flags = _tcb->tcb_tmbx.tm_flags;
169		_tcb->tcb_tmbx.tm_flags |= TMF_NOUPCALL;
170		ret = (_tcb->tcb_curkcb->kcb_kmbx.km_curthread == NULL);
171		_tcb->tcb_tmbx.tm_flags = flags;
172	}
173	return (ret);
174}
175
176static __inline void
177_tcb_set(struct kcb *kcb, struct tcb *tcb)
178{
179        if (tcb == NULL)
180                tcb = &kcb->kcb_faketcb;
181        kcb->kcb_curtcb = tcb;
182        tcb->tcb_curkcb = kcb;
183	_tpr = (uint8_t *)&tcb->tcb_tp + TP_OFFSET;
184}
185
186static __inline struct tcb *
187_tcb_get(void)
188{
189	return (_tcb);
190}
191
192static __inline struct pthread *
193_get_curthread(void)
194{
195	return (_tcb->tcb_thread);
196}
197
198/*
199 * Get the current kse.
200 *
201 * Like _kcb_get(), this can only be called while in a critical region.
202 */
203static __inline struct kse *
204_get_curkse(void)
205{
206	return (_tcb->tcb_curkcb->kcb_kse);
207}
208
209static __inline int
210_thread_enter_uts(struct tcb *tcb, struct kcb *kcb)
211{
212	if (_ppc32_getcontext(&tcb->tcb_tmbx.tm_context.uc_mcontext) == 0) {
213		/* Make the fake tcb the current thread. */
214		kcb->kcb_curtcb = &kcb->kcb_faketcb;
215		_tpr = (uint8_t *)&kcb->kcb_faketcb.tcb_tp + TP_OFFSET;
216		_ppc32_enter_uts(&kcb->kcb_kmbx, kcb->kcb_kmbx.km_func,
217		    kcb->kcb_kmbx.km_stack.ss_sp,
218		    kcb->kcb_kmbx.km_stack.ss_size - 32);
219		/* We should not reach here. */
220		return (-1);
221	}
222	return (0);
223}
224
225static __inline int
226_thread_switch(struct kcb *kcb, struct tcb *tcb, int setmbox)
227{
228	mcontext_t *mc;
229	extern int _libkse_debug;
230
231	_tcb_set(kcb, tcb);
232	mc = &tcb->tcb_tmbx.tm_context.uc_mcontext;
233
234	/*
235	 * A full context needs a system call to restore, so use
236	 * kse_switchin. Otherwise, the partial context can be
237	 * restored with _ppc32_setcontext
238	 */
239	if (mc->mc_vers != _MC_VERSION_KSE && _libkse_debug != 0) {
240		if (setmbox)
241			kse_switchin(&tcb->tcb_tmbx, KSE_SWITCHIN_SETTMBX);
242                else
243                        kse_switchin(&tcb->tcb_tmbx, 0);
244	} else {
245		tcb->tcb_tmbx.tm_lwp = kcb->kcb_kmbx.km_lwp;
246		if (setmbox)
247			_ppc32_setcontext(mc, (intptr_t)&tcb->tcb_tmbx,
248			    (intptr_t *)&kcb->kcb_kmbx.km_curthread);
249		else
250			_ppc32_setcontext(mc, 0, NULL);
251	}
252
253	/* We should not reach here. */
254	return (-1);
255}
256
257#endif /* _PTHREAD_MD_H_ */
258