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 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 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 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 119 dtrace_toxic_ranges(void (*func)(uintptr_t base, uintptr_t limit)) 120 { 121 /* 122 * No toxic regions? 123 */ 124 } 125 126 static int64_t tgt_cpu_tsc; 127 static int64_t hst_cpu_tsc; 128 static int64_t timebase_skew[MAXCPU]; 129 static uint64_t nsec_scale; 130 131 /* See below for the explanation of this macro. */ 132 /* This is taken from the amd64 dtrace_subr, to provide a synchronized timer 133 * between multiple processors in dtrace. Since PowerPC Timebases can be much 134 * lower than x86, the scale shift is 26 instead of 28, allowing for a 15.63MHz 135 * timebase. 136 */ 137 #define SCALE_SHIFT 26 138 139 static void 140 dtrace_gethrtime_init_cpu(void *arg) 141 { 142 uintptr_t cpu = (uintptr_t) arg; 143 144 if (cpu == curcpu) 145 tgt_cpu_tsc = mftb(); 146 else 147 hst_cpu_tsc = mftb(); 148 } 149 150 static void 151 dtrace_gethrtime_init(void *arg) 152 { 153 struct pcpu *pc; 154 uint64_t tb_f; 155 cpuset_t map; 156 int i; 157 158 tb_f = cpu_tickrate(); 159 160 /* 161 * The following line checks that nsec_scale calculated below 162 * doesn't overflow 32-bit unsigned integer, so that it can multiply 163 * another 32-bit integer without overflowing 64-bit. 164 * Thus minimum supported Timebase frequency is 15.63MHz. 165 */ 166 KASSERT(tb_f > (NANOSEC >> (32 - SCALE_SHIFT)), ("Timebase frequency is too low")); 167 168 /* 169 * We scale up NANOSEC/tb_f ratio to preserve as much precision 170 * as possible. 171 * 2^26 factor was chosen quite arbitrarily from practical 172 * considerations: 173 * - it supports TSC frequencies as low as 15.63MHz (see above); 174 */ 175 nsec_scale = ((uint64_t)NANOSEC << SCALE_SHIFT) / tb_f; 176 177 /* The current CPU is the reference one. */ 178 sched_pin(); 179 timebase_skew[curcpu] = 0; 180 CPU_FOREACH(i) { 181 if (i == curcpu) 182 continue; 183 184 pc = pcpu_find(i); 185 CPU_SETOF(PCPU_GET(cpuid), &map); 186 CPU_SET(pc->pc_cpuid, &map); 187 188 smp_rendezvous_cpus(map, NULL, 189 dtrace_gethrtime_init_cpu, 190 smp_no_rendezvous_barrier, (void *)(uintptr_t) i); 191 192 timebase_skew[i] = tgt_cpu_tsc - hst_cpu_tsc; 193 } 194 sched_unpin(); 195 } 196 #ifdef EARLY_AP_STARTUP 197 SYSINIT(dtrace_gethrtime_init, SI_SUB_DTRACE, SI_ORDER_ANY, 198 dtrace_gethrtime_init, NULL); 199 #else 200 SYSINIT(dtrace_gethrtime_init, SI_SUB_SMP, SI_ORDER_ANY, dtrace_gethrtime_init, 201 NULL); 202 #endif 203 204 /* 205 * DTrace needs a high resolution time function which can 206 * be called from a probe context and guaranteed not to have 207 * instrumented with probes itself. 208 * 209 * Returns nanoseconds since boot. 210 */ 211 uint64_t 212 dtrace_gethrtime(void) 213 { 214 uint64_t timebase; 215 uint32_t lo; 216 uint32_t hi; 217 218 /* 219 * We split timebase value into lower and higher 32-bit halves and separately 220 * scale them with nsec_scale, then we scale them down by 2^28 221 * (see nsec_scale calculations) taking into account 32-bit shift of 222 * the higher half and finally add. 223 */ 224 timebase = mftb() - timebase_skew[curcpu]; 225 lo = timebase; 226 hi = timebase >> 32; 227 return (((lo * nsec_scale) >> SCALE_SHIFT) + 228 ((hi * nsec_scale) << (32 - SCALE_SHIFT))); 229 } 230 231 uint64_t 232 dtrace_gethrestime(void) 233 { 234 struct timespec curtime; 235 236 dtrace_getnanotime(&curtime); 237 238 return (curtime.tv_sec * 1000000000UL + curtime.tv_nsec); 239 } 240 241 /* Function to handle DTrace traps during probes. See powerpc/powerpc/trap.c */ 242 int 243 dtrace_trap(struct trapframe *frame, u_int type) 244 { 245 uint16_t nofault; 246 247 /* 248 * A trap can occur while DTrace executes a probe. Before 249 * executing the probe, DTrace blocks re-scheduling and sets 250 * a flag in its per-cpu flags to indicate that it doesn't 251 * want to fault. On returning from the probe, the no-fault 252 * flag is cleared and finally re-scheduling is enabled. 253 * 254 * Check if DTrace has enabled 'no-fault' mode: 255 */ 256 sched_pin(); 257 nofault = cpu_core[curcpu].cpuc_dtrace_flags & CPU_DTRACE_NOFAULT; 258 sched_unpin(); 259 if (nofault) { 260 KASSERT((frame->srr1 & PSL_EE) == 0, ("interrupts enabled")); 261 /* 262 * There are only a couple of trap types that are expected. 263 * All the rest will be handled in the usual way. 264 */ 265 switch (type) { 266 /* Page fault. */ 267 case EXC_DSI: 268 case EXC_DSE: 269 /* Flag a bad address. */ 270 cpu_core[curcpu].cpuc_dtrace_flags |= CPU_DTRACE_BADADDR; 271 cpu_core[curcpu].cpuc_dtrace_illval = frame->dar; 272 273 /* 274 * Offset the instruction pointer to the instruction 275 * following the one causing the fault. 276 */ 277 frame->srr0 += sizeof(int); 278 return (1); 279 case EXC_ISI: 280 case EXC_ISE: 281 /* Flag a bad address. */ 282 cpu_core[curcpu].cpuc_dtrace_flags |= CPU_DTRACE_BADADDR; 283 cpu_core[curcpu].cpuc_dtrace_illval = frame->srr0; 284 285 /* 286 * Offset the instruction pointer to the instruction 287 * following the one causing the fault. 288 */ 289 frame->srr0 += sizeof(int); 290 return (1); 291 default: 292 /* Handle all other traps in the usual way. */ 293 break; 294 } 295 } 296 297 /* Handle the trap in the usual way. */ 298 return (0); 299 } 300 301 void 302 dtrace_probe_error(dtrace_state_t *state, dtrace_epid_t epid, int which, 303 int fault, int fltoffs, uintptr_t illval) 304 { 305 306 dtrace_probe(dtrace_probeid_error, (uint64_t)(uintptr_t)state, 307 (uintptr_t)epid, 308 (uintptr_t)which, (uintptr_t)fault, (uintptr_t)fltoffs); 309 } 310 311 static int 312 dtrace_invop_start(struct trapframe *frame) 313 { 314 315 switch (dtrace_invop(frame->srr0, frame, frame->fixreg[3])) { 316 case DTRACE_INVOP_JUMP: 317 break; 318 case DTRACE_INVOP_BCTR: 319 frame->srr0 = frame->ctr; 320 break; 321 case DTRACE_INVOP_BLR: 322 frame->srr0 = frame->lr; 323 break; 324 case DTRACE_INVOP_MFLR_R0: 325 frame->fixreg[0] = frame->lr; 326 frame->srr0 = frame->srr0 + 4; 327 break; 328 default: 329 return (-1); 330 } 331 return (0); 332 } 333 334 void dtrace_invop_init(void) 335 { 336 dtrace_invop_jump_addr = dtrace_invop_start; 337 } 338 339 void dtrace_invop_uninit(void) 340 { 341 dtrace_invop_jump_addr = 0; 342 } 343