1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License, Version 1.0 only
6 * (the "License"). You may not use this file except in compliance
7 * with the License.
8 *
9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10 * or http://www.opensolaris.org/os/licensing.
11 * See the License for the specific language governing permissions
12 * and limitations under the License.
13 *
14 * When distributing Covered Code, include this CDDL HEADER in each
15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16 * If applicable, add the following below this CDDL HEADER, with the
17 * fields enclosed by brackets "[]" replaced with your own identifying
18 * information: Portions Copyright [yyyy] [name of copyright owner]
19 *
20 * CDDL HEADER END
21 *
22 */
23 /*
24 * Copyright 2005 Sun Microsystems, Inc. All rights reserved.
25 * Use is subject to license terms.
26 */
27
28 #include <sys/param.h>
29 #include <sys/systm.h>
30 #include <sys/kernel.h>
31 #include <sys/malloc.h>
32 #include <sys/kmem.h>
33 #include <sys/proc.h>
34 #include <sys/smp.h>
35 #include <sys/dtrace_impl.h>
36 #include <sys/dtrace_bsd.h>
37 #include <cddl/dev/dtrace/dtrace_cddl.h>
38 #include <machine/clock.h>
39 #include <machine/frame.h>
40 #include <machine/trap.h>
41 #include <vm/pmap.h>
42
43 #define DELAYBRANCH(x) ((int)(x) < 0)
44
45 extern dtrace_id_t dtrace_probeid_error;
46 extern int (*dtrace_invop_jump_addr)(struct trapframe *);
47
48 extern void dtrace_getnanotime(struct timespec *tsp);
49
50 int dtrace_invop(uintptr_t, struct trapframe *, uintptr_t);
51 void dtrace_invop_init(void);
52 void dtrace_invop_uninit(void);
53
54 typedef struct dtrace_invop_hdlr {
55 int (*dtih_func)(uintptr_t, struct trapframe *, uintptr_t);
56 struct dtrace_invop_hdlr *dtih_next;
57 } dtrace_invop_hdlr_t;
58
59 dtrace_invop_hdlr_t *dtrace_invop_hdlr;
60
61 int
dtrace_invop(uintptr_t addr,struct trapframe * frame,uintptr_t arg0)62 dtrace_invop(uintptr_t addr, struct trapframe *frame, uintptr_t arg0)
63 {
64 struct thread *td;
65 dtrace_invop_hdlr_t *hdlr;
66 int rval;
67
68 rval = 0;
69 td = curthread;
70 td->t_dtrace_trapframe = frame;
71 for (hdlr = dtrace_invop_hdlr; hdlr != NULL; hdlr = hdlr->dtih_next)
72 if ((rval = hdlr->dtih_func(addr, frame, arg0)) != 0)
73 break;
74 td->t_dtrace_trapframe = NULL;
75 return (rval);
76 }
77
78 void
dtrace_invop_add(int (* func)(uintptr_t,struct trapframe *,uintptr_t))79 dtrace_invop_add(int (*func)(uintptr_t, struct trapframe *, uintptr_t))
80 {
81 dtrace_invop_hdlr_t *hdlr;
82
83 hdlr = kmem_alloc(sizeof (dtrace_invop_hdlr_t), KM_SLEEP);
84 hdlr->dtih_func = func;
85 hdlr->dtih_next = dtrace_invop_hdlr;
86 dtrace_invop_hdlr = hdlr;
87 }
88
89 void
dtrace_invop_remove(int (* func)(uintptr_t,struct trapframe *,uintptr_t))90 dtrace_invop_remove(int (*func)(uintptr_t, struct trapframe *, uintptr_t))
91 {
92 dtrace_invop_hdlr_t *hdlr = dtrace_invop_hdlr, *prev = NULL;
93
94 for (;;) {
95 if (hdlr == NULL)
96 panic("attempt to remove non-existent invop handler");
97
98 if (hdlr->dtih_func == func)
99 break;
100
101 prev = hdlr;
102 hdlr = hdlr->dtih_next;
103 }
104
105 if (prev == NULL) {
106 ASSERT(dtrace_invop_hdlr == hdlr);
107 dtrace_invop_hdlr = hdlr->dtih_next;
108 } else {
109 ASSERT(dtrace_invop_hdlr != hdlr);
110 prev->dtih_next = hdlr->dtih_next;
111 }
112
113 kmem_free(hdlr, 0);
114 }
115
116
117 /*ARGSUSED*/
118 void
dtrace_toxic_ranges(void (* func)(uintptr_t base,uintptr_t limit))119 dtrace_toxic_ranges(void (*func)(uintptr_t base, uintptr_t limit))
120 {
121 /*
122 * No toxic regions?
123 */
124 }
125
126 void
dtrace_xcall(processorid_t cpu,dtrace_xcall_t func,void * arg)127 dtrace_xcall(processorid_t cpu, dtrace_xcall_t func, void *arg)
128 {
129 cpuset_t cpus;
130
131 if (cpu == DTRACE_CPUALL)
132 cpus = all_cpus;
133 else
134 CPU_SETOF(cpu, &cpus);
135
136 smp_rendezvous_cpus(cpus, smp_no_rendezvous_barrier, func,
137 smp_no_rendezvous_barrier, arg);
138 }
139
140 static void
dtrace_sync_func(void)141 dtrace_sync_func(void)
142 {
143 }
144
145 void
dtrace_sync(void)146 dtrace_sync(void)
147 {
148 dtrace_xcall(DTRACE_CPUALL, (dtrace_xcall_t)dtrace_sync_func, NULL);
149 }
150
151 static int64_t tgt_cpu_tsc;
152 static int64_t hst_cpu_tsc;
153 static int64_t timebase_skew[MAXCPU];
154 static uint64_t nsec_scale;
155
156 /* See below for the explanation of this macro. */
157 /* This is taken from the amd64 dtrace_subr, to provide a synchronized timer
158 * between multiple processors in dtrace. Since PowerPC Timebases can be much
159 * lower than x86, the scale shift is 26 instead of 28, allowing for a 15.63MHz
160 * timebase.
161 */
162 #define SCALE_SHIFT 26
163
164 static void
dtrace_gethrtime_init_cpu(void * arg)165 dtrace_gethrtime_init_cpu(void *arg)
166 {
167 uintptr_t cpu = (uintptr_t) arg;
168
169 if (cpu == curcpu)
170 tgt_cpu_tsc = mftb();
171 else
172 hst_cpu_tsc = mftb();
173 }
174
175 static void
dtrace_gethrtime_init(void * arg)176 dtrace_gethrtime_init(void *arg)
177 {
178 struct pcpu *pc;
179 uint64_t tb_f;
180 cpuset_t map;
181 int i;
182
183 tb_f = cpu_tickrate();
184
185 /*
186 * The following line checks that nsec_scale calculated below
187 * doesn't overflow 32-bit unsigned integer, so that it can multiply
188 * another 32-bit integer without overflowing 64-bit.
189 * Thus minimum supported Timebase frequency is 15.63MHz.
190 */
191 KASSERT(tb_f > (NANOSEC >> (32 - SCALE_SHIFT)), ("Timebase frequency is too low"));
192
193 /*
194 * We scale up NANOSEC/tb_f ratio to preserve as much precision
195 * as possible.
196 * 2^26 factor was chosen quite arbitrarily from practical
197 * considerations:
198 * - it supports TSC frequencies as low as 15.63MHz (see above);
199 */
200 nsec_scale = ((uint64_t)NANOSEC << SCALE_SHIFT) / tb_f;
201
202 /* The current CPU is the reference one. */
203 sched_pin();
204 timebase_skew[curcpu] = 0;
205 CPU_FOREACH(i) {
206 if (i == curcpu)
207 continue;
208
209 pc = pcpu_find(i);
210 CPU_SETOF(PCPU_GET(cpuid), &map);
211 CPU_SET(pc->pc_cpuid, &map);
212
213 smp_rendezvous_cpus(map, NULL,
214 dtrace_gethrtime_init_cpu,
215 smp_no_rendezvous_barrier, (void *)(uintptr_t) i);
216
217 timebase_skew[i] = tgt_cpu_tsc - hst_cpu_tsc;
218 }
219 sched_unpin();
220 }
221 #ifdef EARLY_AP_STARTUP
222 SYSINIT(dtrace_gethrtime_init, SI_SUB_DTRACE, SI_ORDER_ANY,
223 dtrace_gethrtime_init, NULL);
224 #else
225 SYSINIT(dtrace_gethrtime_init, SI_SUB_SMP, SI_ORDER_ANY, dtrace_gethrtime_init,
226 NULL);
227 #endif
228
229 /*
230 * DTrace needs a high resolution time function which can
231 * be called from a probe context and guaranteed not to have
232 * instrumented with probes itself.
233 *
234 * Returns nanoseconds since boot.
235 */
236 uint64_t
dtrace_gethrtime(void)237 dtrace_gethrtime(void)
238 {
239 uint64_t timebase;
240 uint32_t lo;
241 uint32_t hi;
242
243 /*
244 * We split timebase value into lower and higher 32-bit halves and separately
245 * scale them with nsec_scale, then we scale them down by 2^28
246 * (see nsec_scale calculations) taking into account 32-bit shift of
247 * the higher half and finally add.
248 */
249 timebase = mftb() - timebase_skew[curcpu];
250 lo = timebase;
251 hi = timebase >> 32;
252 return (((lo * nsec_scale) >> SCALE_SHIFT) +
253 ((hi * nsec_scale) << (32 - SCALE_SHIFT)));
254 }
255
256 uint64_t
dtrace_gethrestime(void)257 dtrace_gethrestime(void)
258 {
259 struct timespec curtime;
260
261 dtrace_getnanotime(&curtime);
262
263 return (curtime.tv_sec * 1000000000UL + curtime.tv_nsec);
264 }
265
266 /* Function to handle DTrace traps during probes. See powerpc/powerpc/trap.c */
267 int
dtrace_trap(struct trapframe * frame,u_int type)268 dtrace_trap(struct trapframe *frame, u_int type)
269 {
270 uint16_t nofault;
271
272 /*
273 * A trap can occur while DTrace executes a probe. Before
274 * executing the probe, DTrace blocks re-scheduling and sets
275 * a flag in its per-cpu flags to indicate that it doesn't
276 * want to fault. On returning from the probe, the no-fault
277 * flag is cleared and finally re-scheduling is enabled.
278 *
279 * Check if DTrace has enabled 'no-fault' mode:
280 */
281 sched_pin();
282 nofault = cpu_core[curcpu].cpuc_dtrace_flags & CPU_DTRACE_NOFAULT;
283 sched_unpin();
284 if (nofault) {
285 KASSERT((frame->srr1 & PSL_EE) == 0, ("interrupts enabled"));
286 /*
287 * There are only a couple of trap types that are expected.
288 * All the rest will be handled in the usual way.
289 */
290 switch (type) {
291 /* Page fault. */
292 case EXC_DSI:
293 case EXC_DSE:
294 /* Flag a bad address. */
295 cpu_core[curcpu].cpuc_dtrace_flags |= CPU_DTRACE_BADADDR;
296 cpu_core[curcpu].cpuc_dtrace_illval = frame->dar;
297
298 /*
299 * Offset the instruction pointer to the instruction
300 * following the one causing the fault.
301 */
302 frame->srr0 += sizeof(int);
303 return (1);
304 case EXC_ISI:
305 case EXC_ISE:
306 /* Flag a bad address. */
307 cpu_core[curcpu].cpuc_dtrace_flags |= CPU_DTRACE_BADADDR;
308 cpu_core[curcpu].cpuc_dtrace_illval = frame->srr0;
309
310 /*
311 * Offset the instruction pointer to the instruction
312 * following the one causing the fault.
313 */
314 frame->srr0 += sizeof(int);
315 return (1);
316 default:
317 /* Handle all other traps in the usual way. */
318 break;
319 }
320 }
321
322 /* Handle the trap in the usual way. */
323 return (0);
324 }
325
326 void
dtrace_probe_error(dtrace_state_t * state,dtrace_epid_t epid,int which,int fault,int fltoffs,uintptr_t illval)327 dtrace_probe_error(dtrace_state_t *state, dtrace_epid_t epid, int which,
328 int fault, int fltoffs, uintptr_t illval)
329 {
330
331 dtrace_probe(dtrace_probeid_error, (uint64_t)(uintptr_t)state,
332 (uintptr_t)epid,
333 (uintptr_t)which, (uintptr_t)fault, (uintptr_t)fltoffs);
334 }
335
336 static int
dtrace_invop_start(struct trapframe * frame)337 dtrace_invop_start(struct trapframe *frame)
338 {
339
340 switch (dtrace_invop(frame->srr0, frame, frame->fixreg[3])) {
341 case DTRACE_INVOP_JUMP:
342 break;
343 case DTRACE_INVOP_BCTR:
344 frame->srr0 = frame->ctr;
345 break;
346 case DTRACE_INVOP_BLR:
347 frame->srr0 = frame->lr;
348 break;
349 case DTRACE_INVOP_MFLR_R0:
350 frame->fixreg[0] = frame->lr;
351 frame->srr0 = frame->srr0 + 4;
352 break;
353 default:
354 return (-1);
355 }
356 return (0);
357 }
358
dtrace_invop_init(void)359 void dtrace_invop_init(void)
360 {
361 dtrace_invop_jump_addr = dtrace_invop_start;
362 }
363
dtrace_invop_uninit(void)364 void dtrace_invop_uninit(void)
365 {
366 dtrace_invop_jump_addr = 0;
367 }
368