FreeBSD/Linux Kernel Cross Reference
sys/dev/tpm/tpm_tis.c
1 /*-
2 * Copyright (c) 2018 Stormshield.
3 * Copyright (c) 2018 Semihalf.
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
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
17 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
18 * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
19 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
20 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
21 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
23 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
24 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
25 * POSSIBILITY OF SUCH DAMAGE.
26 */
27
28 #include <sys/cdefs.h>
29 __FBSDID("$FreeBSD$");
30
31 #include "tpm20.h"
32
33 /*
34 * TIS register space as defined in
35 * TCG_PC_Client_Platform_TPM_Profile_PTP_2.0_r1.03_v22
36 */
37 #define TPM_ACCESS 0x0
38 #define TPM_INT_ENABLE 0x8
39 #define TPM_INT_VECTOR 0xc
40 #define TPM_INT_STS 0x10
41 #define TPM_INTF_CAPS 0x14
42 #define TPM_STS 0x18
43 #define TPM_DATA_FIFO 0x24
44 #define TPM_INTF_ID 0x30
45 #define TPM_XDATA_FIFO 0x80
46 #define TPM_DID_VID 0xF00
47 #define TPM_RID 0xF04
48
49 #define TPM_ACCESS_LOC_REQ BIT(1)
50 #define TPM_ACCESS_LOC_Seize BIT(3)
51 #define TPM_ACCESS_LOC_ACTIVE BIT(5)
52 #define TPM_ACCESS_LOC_RELINQUISH BIT(5)
53 #define TPM_ACCESS_VALID BIT(7)
54
55 #define TPM_INT_ENABLE_GLOBAL_ENABLE BIT(31)
56 #define TPM_INT_ENABLE_CMD_RDY BIT(7)
57 #define TPM_INT_ENABLE_LOC_CHANGE BIT(2)
58 #define TPM_INT_ENABLE_STS_VALID BIT(1)
59 #define TPM_INT_ENABLE_DATA_AVAIL BIT(0)
60
61 #define TPM_INT_STS_CMD_RDY BIT(7)
62 #define TPM_INT_STS_LOC_CHANGE BIT(2)
63 #define TPM_INT_STS_VALID BIT(1)
64 #define TPM_INT_STS_DATA_AVAIL BIT(0)
65
66 #define TPM_INTF_CAPS_VERSION 0x70000000
67 #define TPM_INTF_CAPS_TPM20 0x30000000
68
69 #define TPM_STS_VALID BIT(7)
70 #define TPM_STS_CMD_RDY BIT(6)
71 #define TPM_STS_CMD_START BIT(5)
72 #define TPM_STS_DATA_AVAIL BIT(4)
73 #define TPM_STS_DATA_EXPECTED BIT(3)
74 #define TPM_STS_BURST_MASK 0xFFFF00
75 #define TPM_STS_BURST_OFFSET 0x8
76
77 static int tpmtis_transmit(struct tpm_sc *sc, size_t length);
78
79 static int tpmtis_acpi_probe(device_t dev);
80 static int tpmtis_attach(device_t dev);
81 static int tpmtis_detach(device_t dev);
82
83 static void tpmtis_intr_handler(void *arg);
84
85 static void tpmtis_setup_intr(struct tpm_sc *sc);
86
87 static bool tpmtis_read_bytes(struct tpm_sc *sc, size_t count, uint8_t *buf);
88 static bool tpmtis_write_bytes(struct tpm_sc *sc, size_t count, uint8_t *buf);
89 static bool tpmtis_request_locality(struct tpm_sc *sc, int locality);
90 static void tpmtis_relinquish_locality(struct tpm_sc *sc);
91 static bool tpmtis_go_ready(struct tpm_sc *sc);
92
93 static bool tpm_wait_for_u32(struct tpm_sc *sc, bus_size_t off,
94 uint32_t mask, uint32_t val, int32_t timeout);
95
96 static uint16_t tpmtis_wait_for_burst(struct tpm_sc *sc);
97
98 char *tpmtis_ids[] = {"MSFT0101", NULL};
99
100 static int
101 tpmtis_acpi_probe(device_t dev)
102 {
103 int err;
104 ACPI_TABLE_TPM23 *tbl;
105 ACPI_STATUS status;
106
107 err = ACPI_ID_PROBE(device_get_parent(dev), dev, tpmtis_ids, NULL);
108 if (err > 0)
109 return (err);
110 /*Find TPM2 Header*/
111 status = AcpiGetTable(ACPI_SIG_TPM2, 1, (ACPI_TABLE_HEADER **) &tbl);
112 if(ACPI_FAILURE(status) ||
113 tbl->StartMethod != TPM2_START_METHOD_TIS)
114 err = ENXIO;
115
116 device_set_desc(dev, "Trusted Platform Module 2.0, FIFO mode");
117 return (err);
118 }
119
120 static int
121 tpmtis_attach(device_t dev)
122 {
123 struct tpm_sc *sc;
124 int result;
125
126 sc = device_get_softc(dev);
127 sc->dev = dev;
128 sc->transmit = tpmtis_transmit;
129 sc->intr_type = -1;
130
131 sx_init(&sc->dev_lock, "TPM driver lock");
132 sc->buf = malloc(TPM_BUFSIZE, M_TPM20, M_WAITOK);
133
134 sc->mem_rid = 0;
135 sc->mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &sc->mem_rid,
136 RF_ACTIVE);
137 if (sc->mem_res == NULL) {
138 tpmtis_detach(dev);
139 return (ENXIO);
140 }
141
142 sc->irq_rid = 0;
143 sc->irq_res = bus_alloc_resource_any(dev, SYS_RES_IRQ, &sc->irq_rid,
144 RF_ACTIVE | RF_SHAREABLE);
145 if (sc->irq_res == NULL)
146 goto skip_irq;
147
148 result = bus_setup_intr(dev, sc->irq_res, INTR_TYPE_MISC | INTR_MPSAFE,
149 NULL, tpmtis_intr_handler, sc, &sc->intr_cookie);
150 if (result != 0) {
151 bus_release_resource(dev, SYS_RES_IRQ, sc->irq_rid, sc->irq_res);
152 goto skip_irq;
153 }
154 tpmtis_setup_intr(sc);
155
156 skip_irq:
157 result = tpm20_init(sc);
158 if (result != 0)
159 tpmtis_detach(dev);
160
161 return (result);
162 }
163
164 static int
165 tpmtis_detach(device_t dev)
166 {
167 struct tpm_sc *sc;
168
169 sc = device_get_softc(dev);
170 tpm20_release(sc);
171
172 if (sc->intr_cookie != NULL)
173 bus_teardown_intr(dev, sc->irq_res, sc->intr_cookie);
174
175 if (sc->irq_res != NULL)
176 bus_release_resource(dev, SYS_RES_IRQ,
177 sc->irq_rid, sc->irq_res);
178
179 if (sc->mem_res != NULL)
180 bus_release_resource(dev, SYS_RES_MEMORY,
181 sc->mem_rid, sc->mem_res);
182
183 return (0);
184 }
185
186 /*
187 * Test if the advertisted interrupt actually works.
188 * This sends a simple command. (GetRandom)
189 * Interrupts are then enabled in the handler.
190 */
191 static void
192 tpmtis_test_intr(struct tpm_sc *sc)
193 {
194 uint8_t cmd[] = {
195 0x80, 0x01, /* TPM_ST_NO_SESSIONS tag*/
196 0x00, 0x00, 0x00, 0x0c, /* cmd length */
197 0x00, 0x00, 0x01, 0x7b, /* cmd TPM_CC_GetRandom */
198 0x00, 0x01 /* number of bytes requested */
199 };
200
201 sx_xlock(&sc->dev_lock);
202 memcpy(sc->buf, cmd, sizeof(cmd));
203 tpmtis_transmit(sc, sizeof(cmd));
204 sc->pending_data_length = 0;
205 sx_xunlock(&sc->dev_lock);
206 }
207
208 static void
209 tpmtis_setup_intr(struct tpm_sc *sc)
210 {
211 uint32_t reg;
212 uint8_t irq;
213
214 irq = bus_get_resource_start(sc->dev, SYS_RES_IRQ, sc->irq_rid);
215
216 /*
217 * SIRQ has to be between 1 - 15.
218 * I found a system with ACPI table that reported a value of 0x2d.
219 * An attempt to use such value resulted in an interrupt storm.
220 */
221 if (irq == 0 || irq > 0xF)
222 return;
223
224 if(!tpmtis_request_locality(sc, 0))
225 sc->interrupts = false;
226
227 WR1(sc, TPM_INT_VECTOR, irq);
228
229 /* Clear all pending interrupts. */
230 reg = RD4(sc, TPM_INT_STS);
231 WR4(sc, TPM_INT_STS, reg);
232
233 reg = RD4(sc, TPM_INT_ENABLE);
234 reg |= TPM_INT_ENABLE_GLOBAL_ENABLE |
235 TPM_INT_ENABLE_DATA_AVAIL |
236 TPM_INT_ENABLE_LOC_CHANGE |
237 TPM_INT_ENABLE_CMD_RDY |
238 TPM_INT_ENABLE_STS_VALID;
239 WR4(sc, TPM_INT_ENABLE, reg);
240
241 tpmtis_relinquish_locality(sc);
242 tpmtis_test_intr(sc);
243 }
244
245 static void
246 tpmtis_intr_handler(void *arg)
247 {
248 struct tpm_sc *sc;
249 uint32_t status;
250
251 sc = (struct tpm_sc *)arg;
252 status = RD4(sc, TPM_INT_STS);
253
254 WR4(sc, TPM_INT_STS, status);
255
256 /* Check for stray interrupts. */
257 if (sc->intr_type == -1 || (sc->intr_type & status) == 0)
258 return;
259
260 sc->interrupts = true;
261 wakeup(sc);
262 }
263
264 static bool
265 tpm_wait_for_u32(struct tpm_sc *sc, bus_size_t off, uint32_t mask, uint32_t val,
266 int32_t timeout)
267 {
268
269 /* Check for condition */
270 if ((RD4(sc, off) & mask) == val)
271 return (true);
272
273 /* If interrupts are enabled sleep for timeout duration */
274 if(sc->interrupts && sc->intr_type != -1) {
275 tsleep(sc, PWAIT, "TPM WITH INTERRUPTS", timeout / tick);
276
277 sc->intr_type = -1;
278 return ((RD4(sc, off) & mask) == val);
279 }
280
281 /* If we don't have interrupts poll the device every tick */
282 while (timeout > 0) {
283 if ((RD4(sc, off) & mask) == val)
284 return (true);
285
286 pause("TPM POLLING", 1);
287 timeout -= tick;
288 }
289 return (false);
290 }
291
292 static uint16_t
293 tpmtis_wait_for_burst(struct tpm_sc *sc)
294 {
295 int timeout;
296 uint16_t burst_count;
297
298 timeout = TPM_TIMEOUT_A;
299
300 while (timeout-- > 0) {
301 burst_count = (RD4(sc, TPM_STS) & TPM_STS_BURST_MASK) >>
302 TPM_STS_BURST_OFFSET;
303 if (burst_count > 0)
304 break;
305
306 DELAY(1);
307 }
308 return (burst_count);
309 }
310
311 static bool
312 tpmtis_read_bytes(struct tpm_sc *sc, size_t count, uint8_t *buf)
313 {
314 uint16_t burst_count;
315
316 while (count > 0) {
317 burst_count = tpmtis_wait_for_burst(sc);
318 if (burst_count == 0)
319 return (false);
320
321 burst_count = MIN(burst_count, count);
322 count -= burst_count;
323
324 while (burst_count-- > 0)
325 *buf++ = RD1(sc, TPM_DATA_FIFO);
326 }
327
328 return (true);
329 }
330
331 static bool
332 tpmtis_write_bytes(struct tpm_sc *sc, size_t count, uint8_t *buf)
333 {
334 uint16_t burst_count;
335
336 while (count > 0) {
337 burst_count = tpmtis_wait_for_burst(sc);
338 if (burst_count == 0)
339 return (false);
340
341 burst_count = MIN(burst_count, count);
342 count -= burst_count;
343
344 while (burst_count-- > 0)
345 WR1(sc, TPM_DATA_FIFO, *buf++);
346 }
347
348 return (true);
349 }
350
351 static bool
352 tpmtis_request_locality(struct tpm_sc *sc, int locality)
353 {
354 uint8_t mask;
355 int timeout;
356
357 /* Currently we only support Locality 0 */
358 if (locality != 0)
359 return (false);
360
361 mask = TPM_ACCESS_LOC_ACTIVE | TPM_ACCESS_VALID;
362 timeout = TPM_TIMEOUT_A;
363 sc->intr_type = TPM_INT_STS_LOC_CHANGE;
364
365 WR1(sc, TPM_ACCESS, TPM_ACCESS_LOC_REQ);
366 bus_barrier(sc->mem_res, TPM_ACCESS, 1, BUS_SPACE_BARRIER_WRITE);
367 if(sc->interrupts) {
368 tsleep(sc, PWAIT, "TPMLOCREQUEST with INTR", timeout / tick);
369 return ((RD1(sc, TPM_ACCESS) & mask) == mask);
370 } else {
371 while(timeout > 0) {
372 if ((RD1(sc, TPM_ACCESS) & mask) == mask)
373 return (true);
374
375 pause("TPMLOCREQUEST POLLING", 1);
376 timeout -= tick;
377 }
378 }
379
380 return (false);
381 }
382
383 static void
384 tpmtis_relinquish_locality(struct tpm_sc *sc)
385 {
386
387 /*
388 * Interrupts can only be cleared when a locality is active.
389 * Clear them now in case interrupt handler didn't make it in time.
390 */
391 if(sc->interrupts)
392 AND4(sc, TPM_INT_STS, RD4(sc, TPM_INT_STS));
393
394 OR1(sc, TPM_ACCESS, TPM_ACCESS_LOC_RELINQUISH);
395 }
396
397 static bool
398 tpmtis_go_ready(struct tpm_sc *sc)
399 {
400 uint32_t mask;
401
402 mask = TPM_STS_CMD_RDY;
403 sc->intr_type = TPM_INT_STS_CMD_RDY;
404
405 WR4(sc, TPM_STS, TPM_STS_CMD_RDY);
406 bus_barrier(sc->mem_res, TPM_STS, 4, BUS_SPACE_BARRIER_WRITE);
407 if (!tpm_wait_for_u32(sc, TPM_STS, mask, mask, TPM_TIMEOUT_B))
408 return (false);
409
410 return (true);
411 }
412
413 static int
414 tpmtis_transmit(struct tpm_sc *sc, size_t length)
415 {
416 size_t bytes_available;
417 uint32_t mask, curr_cmd;
418 int timeout;
419
420 sx_assert(&sc->dev_lock, SA_XLOCKED);
421
422 if (!tpmtis_request_locality(sc, 0)) {
423 device_printf(sc->dev,
424 "Failed to obtain locality\n");
425 return (EIO);
426 }
427 if (!tpmtis_go_ready(sc)) {
428 device_printf(sc->dev,
429 "Failed to switch to ready state\n");
430 return (EIO);
431 }
432 if (!tpmtis_write_bytes(sc, length, sc->buf)) {
433 device_printf(sc->dev,
434 "Failed to write cmd to device\n");
435 return (EIO);
436 }
437
438 mask = TPM_STS_VALID;
439 sc->intr_type = TPM_INT_STS_VALID;
440 if (!tpm_wait_for_u32(sc, TPM_STS, mask, mask, TPM_TIMEOUT_C)) {
441 device_printf(sc->dev,
442 "Timeout while waiting for valid bit\n");
443 return (EIO);
444 }
445 if (RD4(sc, TPM_STS) & TPM_STS_DATA_EXPECTED) {
446 device_printf(sc->dev,
447 "Device expects more data even though we already"
448 " sent everything we had\n");
449 return (EIO);
450 }
451
452 /*
453 * Calculate timeout for current command.
454 * Command code is passed in bytes 6-10.
455 */
456 curr_cmd = be32toh(*(uint32_t *) (&sc->buf[6]));
457 timeout = tpm20_get_timeout(curr_cmd);
458
459 WR4(sc, TPM_STS, TPM_STS_CMD_START);
460 bus_barrier(sc->mem_res, TPM_STS, 4, BUS_SPACE_BARRIER_WRITE);
461
462 mask = TPM_STS_DATA_AVAIL | TPM_STS_VALID;
463 sc->intr_type = TPM_INT_STS_DATA_AVAIL;
464 if (!tpm_wait_for_u32(sc, TPM_STS, mask, mask, timeout)) {
465 device_printf(sc->dev,
466 "Timeout while waiting for device to process cmd\n");
467 /*
468 * Switching to ready state also cancels processing
469 * current command
470 */
471 if (!tpmtis_go_ready(sc))
472 return (EIO);
473
474 /*
475 * After canceling a command we should get a response,
476 * check if there is one.
477 */
478 sc->intr_type = TPM_INT_STS_DATA_AVAIL;
479 if (!tpm_wait_for_u32(sc, TPM_STS, mask, mask, TPM_TIMEOUT_C))
480 return (EIO);
481 }
482 /* Read response header. Length is passed in bytes 2 - 6. */
483 if(!tpmtis_read_bytes(sc, TPM_HEADER_SIZE, sc->buf)) {
484 device_printf(sc->dev,
485 "Failed to read response header\n");
486 return (EIO);
487 }
488 bytes_available = be32toh(*(uint32_t *) (&sc->buf[2]));
489
490 if (bytes_available > TPM_BUFSIZE || bytes_available < TPM_HEADER_SIZE) {
491 device_printf(sc->dev,
492 "Incorrect response size: %zu\n",
493 bytes_available);
494 return (EIO);
495 }
496 if(!tpmtis_read_bytes(sc, bytes_available - TPM_HEADER_SIZE,
497 &sc->buf[TPM_HEADER_SIZE])) {
498 device_printf(sc->dev,
499 "Failed to read response\n");
500 return (EIO);
501 }
502 tpmtis_relinquish_locality(sc);
503 sc->pending_data_length = bytes_available;
504
505 return (0);
506 }
507
508 /* ACPI Driver */
509 static device_method_t tpmtis_methods[] = {
510 DEVMETHOD(device_probe, tpmtis_acpi_probe),
511 DEVMETHOD(device_attach, tpmtis_attach),
512 DEVMETHOD(device_detach, tpmtis_detach),
513 DEVMETHOD(device_shutdown, tpm20_shutdown),
514 DEVMETHOD(device_suspend, tpm20_suspend),
515 {0, 0}
516 };
517
518 static driver_t tpmtis_driver = {
519 "tpmtis", tpmtis_methods, sizeof(struct tpm_sc),
520 };
521
522 DRIVER_MODULE(tpmtis, acpi, tpmtis_driver, 0, 0);
Cache object: e5314ac94c9f23439259a9667eaadb6d
|