4 * Implements inline procedure support for the LWKT subsystem.
6 * Generally speaking these routines only operate on threads associated
7 * with the current cpu. For example, a higher priority thread pending
8 * on a different cpu will not be immediately scheduled by a yield() on
12 #ifndef _SYS_THREAD2_H_
13 #define _SYS_THREAD2_H_
17 #error "This file should not be included by userland programs."
22 * Userland will have its own globaldata which it includes prior to this.
25 #include <sys/systm.h>
27 #ifndef _SYS_GLOBALDATA_H_
28 #include <sys/globaldata.h>
30 #include <machine/cpufunc.h>
33 * Is a token held by the specified thread?
36 _lwkt_token_held(lwkt_token_t tok, thread_t td)
38 return ((tok->t_count & ~(TOK_EXCLUSIVE|TOK_EXCLREQ)) ||
39 (tok->t_ref >= &td->td_toks_base &&
40 tok->t_ref < td->td_toks_stop));
44 * Critical section debugging
46 #ifdef DEBUG_CRIT_SECTIONS
47 #define __DEBUG_CRIT_ARG__ const char *id
48 #define __DEBUG_CRIT_ADD_ARG__ , const char *id
49 #define __DEBUG_CRIT_PASS_ARG__ , id
50 #define __DEBUG_CRIT_ENTER(td) _debug_crit_enter((td), id)
51 #define __DEBUG_CRIT_EXIT(td) _debug_crit_exit((td), id)
52 #define crit_enter() _crit_enter(mycpu, __FUNCTION__)
53 #define crit_enter_id(id) _crit_enter(mycpu, id)
54 #define crit_enter_gd(curgd) _crit_enter((curgd), __FUNCTION__)
55 #define crit_enter_quick(curtd) _crit_enter_quick((curtd), __FUNCTION__)
56 #define crit_enter_hard() _crit_enter_hard(mycpu, __FUNCTION__)
57 #define crit_enter_hard_gd(curgd) _crit_enter_hard((curgd), __FUNCTION__)
58 #define crit_exit() _crit_exit(mycpu, __FUNCTION__)
59 #define crit_exit_id(id) _crit_exit(mycpu, id)
60 #define crit_exit_gd(curgd) _crit_exit((curgd), __FUNCTION__)
61 #define crit_exit_quick(curtd) _crit_exit_quick((curtd), __FUNCTION__)
62 #define crit_exit_hard() _crit_exit_hard(mycpu, __FUNCTION__)
63 #define crit_exit_hard_gd(curgd) _crit_exit_hard((curgd), __FUNCTION__)
64 #define crit_exit_noyield(curtd) _crit_exit_noyield((curtd),__FUNCTION__)
66 #define __DEBUG_CRIT_ARG__ void
67 #define __DEBUG_CRIT_ADD_ARG__
68 #define __DEBUG_CRIT_PASS_ARG__
69 #define __DEBUG_CRIT_ENTER(td)
70 #define __DEBUG_CRIT_EXIT(td)
71 #define crit_enter() _crit_enter(mycpu)
72 #define crit_enter_id(id) _crit_enter(mycpu)
73 #define crit_enter_gd(curgd) _crit_enter((curgd))
74 #define crit_enter_quick(curtd) _crit_enter_quick((curtd))
75 #define crit_enter_hard() _crit_enter_hard(mycpu)
76 #define crit_enter_hard_gd(curgd) _crit_enter_hard((curgd))
77 #define crit_exit() crit_exit_wrapper()
78 #define crit_exit_id(id) _crit_exit(mycpu)
79 #define crit_exit_gd(curgd) _crit_exit((curgd))
80 #define crit_exit_quick(curtd) _crit_exit_quick((curtd))
81 #define crit_exit_hard() _crit_exit_hard(mycpu)
82 #define crit_exit_hard_gd(curgd) _crit_exit_hard((curgd))
83 #define crit_exit_noyield(curtd) _crit_exit_noyield((curtd))
86 extern void crit_exit_wrapper(__DEBUG_CRIT_ARG__);
89 * Track crit_enter()/crit_exit() pairs and warn on mismatches.
91 #ifdef DEBUG_CRIT_SECTIONS
94 _debug_crit_enter(thread_t td, const char *id)
96 int wi = td->td_crit_debug_index;
98 td->td_crit_debug_array[wi & CRIT_DEBUG_ARRAY_MASK] = id;
99 ++td->td_crit_debug_index;
103 _debug_crit_exit(thread_t td, const char *id)
108 wi = td->td_crit_debug_index - 1;
109 if ((gid = td->td_crit_debug_array[wi & CRIT_DEBUG_ARRAY_MASK]) != id) {
110 if (td->td_in_crit_report == 0) {
111 td->td_in_crit_report = 1;
112 kprintf("crit_exit(%s) expected id %s\n", id, gid);
113 td->td_in_crit_report = 0;
116 --td->td_crit_debug_index;
122 * Critical sections prevent preemption, but allowing explicit blocking
123 * and thread switching. Any interrupt occuring while in a critical
124 * section is made pending and returns immediately. Interrupts are not
125 * physically disabled.
127 * Hard critical sections prevent preemption and disallow any blocking
128 * or thread switching, and in addition will assert on any blockable
129 * operation (acquire token not already held, lockmgr, mutex ops, or
130 * splz). Spinlocks can still be used in hard sections.
132 * All critical section routines only operate on the current thread.
133 * Passed gd or td arguments are simply optimizations when mycpu or
134 * curthread is already available to the caller.
141 _crit_enter_quick(thread_t td __DEBUG_CRIT_ADD_ARG__)
144 __DEBUG_CRIT_ENTER(td);
149 _crit_enter(globaldata_t gd __DEBUG_CRIT_ADD_ARG__)
151 _crit_enter_quick(gd->gd_curthread __DEBUG_CRIT_PASS_ARG__);
155 _crit_enter_hard(globaldata_t gd __DEBUG_CRIT_ADD_ARG__)
157 _crit_enter_quick(gd->gd_curthread __DEBUG_CRIT_PASS_ARG__);
158 ++gd->gd_intr_nesting_level;
165 * NOTE: Conditionalizing just gd_reqflags, a case which is virtually
166 * never true regardless of crit_count, should result in 100%
167 * optimal code execution. We don't check crit_count because
168 * it just bloats the inline and does not improve performance.
170 * NOTE: This can produce a considerable amount of code despite the
171 * relatively few lines of code so the non-debug case typically
172 * just wraps it in a real function, crit_exit_wrapper().
175 _crit_exit_noyield(thread_t td __DEBUG_CRIT_ADD_ARG__)
177 __DEBUG_CRIT_EXIT(td);
180 if (__predict_false(td->td_critcount < 0))
183 cpu_ccfence(); /* prevent compiler reordering */
187 _crit_exit_quick(thread_t td __DEBUG_CRIT_ADD_ARG__)
189 _crit_exit_noyield(td __DEBUG_CRIT_PASS_ARG__);
190 if (__predict_false(td->td_gd->gd_reqflags & RQF_IDLECHECK_MASK))
195 _crit_exit(globaldata_t gd __DEBUG_CRIT_ADD_ARG__)
197 _crit_exit_quick(gd->gd_curthread __DEBUG_CRIT_PASS_ARG__);
201 _crit_exit_hard(globaldata_t gd __DEBUG_CRIT_ADD_ARG__)
203 --gd->gd_intr_nesting_level;
204 _crit_exit_quick(gd->gd_curthread __DEBUG_CRIT_PASS_ARG__);
208 crit_test(thread_t td)
210 return(td->td_critcount);
214 * Return whether any threads are runnable.
219 return (TAILQ_FIRST(&mycpu->gd_tdrunq) != NULL);
223 lwkt_getpri(thread_t td)
229 lwkt_getpri_self(void)
231 return(lwkt_getpri(curthread));
235 * Reduce our priority in preparation for a return to userland. If
236 * our passive release function was still in place, our priority was
237 * never raised and does not need to be reduced.
239 * See also lwkt_passive_release() and platform/blah/trap.c
242 lwkt_passive_recover(thread_t td)
244 if (td->td_release == NULL)
245 lwkt_setpri_self(TDPRI_USER_NORM);
246 td->td_release = NULL;
253 lwkt_cpusync_init(lwkt_cpusync_t cs, cpumask_t mask,
254 cpusync_func_t func, void *data)
257 /* cs->cs_mack = 0; handled by _interlock */
265 * IPIQ messaging wrappers. IPIQ remote functions are passed three arguments:
266 * a void * pointer, an integer, and a pointer to the trap frame (or NULL if
267 * the trap frame is not known). However, we wish to provide opaque
268 * interfaces for simpler callbacks... the basic IPI messaging function as
269 * used by the kernel takes a single argument.
272 lwkt_send_ipiq(globaldata_t target, ipifunc1_t func, void *arg)
274 return(lwkt_send_ipiq3(target, (ipifunc3_t)func, arg, 0));
278 lwkt_send_ipiq2(globaldata_t target, ipifunc2_t func, void *arg1, int arg2)
280 return(lwkt_send_ipiq3(target, (ipifunc3_t)func, arg1, arg2));
284 lwkt_send_ipiq_mask(cpumask_t mask, ipifunc1_t func, void *arg)
286 return(lwkt_send_ipiq3_mask(mask, (ipifunc3_t)func, arg, 0));
290 lwkt_send_ipiq2_mask(cpumask_t mask, ipifunc2_t func, void *arg1, int arg2)
292 return(lwkt_send_ipiq3_mask(mask, (ipifunc3_t)func, arg1, arg2));
296 lwkt_send_ipiq_nowait(globaldata_t target, ipifunc1_t func, void *arg)
298 return(lwkt_send_ipiq3_nowait(target, (ipifunc3_t)func, arg, 0));
302 lwkt_send_ipiq2_nowait(globaldata_t target, ipifunc2_t func,
303 void *arg1, int arg2)
305 return(lwkt_send_ipiq3_nowait(target, (ipifunc3_t)func, arg1, arg2));
309 lwkt_send_ipiq_passive(globaldata_t target, ipifunc1_t func, void *arg)
311 return(lwkt_send_ipiq3_passive(target, (ipifunc3_t)func, arg, 0));
315 lwkt_send_ipiq2_passive(globaldata_t target, ipifunc2_t func,
316 void *arg1, int arg2)
318 return(lwkt_send_ipiq3_passive(target, (ipifunc3_t)func, arg1, arg2));
322 lwkt_send_ipiq_bycpu(int dcpu, ipifunc1_t func, void *arg)
324 return(lwkt_send_ipiq3_bycpu(dcpu, (ipifunc3_t)func, arg, 0));
328 lwkt_send_ipiq2_bycpu(int dcpu, ipifunc2_t func, void *arg1, int arg2)
330 return(lwkt_send_ipiq3_bycpu(dcpu, (ipifunc3_t)func, arg1, arg2));
335 #endif /* _SYS_THREAD2_H_ */