xref: /freebsd/sys/dev/tpm/tpm_crb.c (revision 5bb3134a8c21cb87b30e135ef168483f0333dabb)
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  * CRB register space as defined in
35  * TCG_PC_Client_Platform_TPM_Profile_PTP_2.0_r1.03_v22
36  */
37 #define	TPM_LOC_STATE			0x0
38 #define	TPM_LOC_CTRL			0x8
39 #define	TPM_LOC_STS			0xC
40 #define	TPM_CRB_INTF_ID			0x30
41 #define	TPM_CRB_CTRL_EXT		0x38
42 #define	TPM_CRB_CTRL_REQ		0x40
43 #define	TPM_CRB_CTRL_STS		0x44
44 #define	TPM_CRB_CTRL_CANCEL		0x48
45 #define	TPM_CRB_CTRL_START		0x4C
46 #define	TPM_CRB_INT_ENABLE		0x50
47 #define	TPM_CRB_INT_STS			0x54
48 #define	TPM_CRB_CTRL_CMD_SIZE		0x58
49 #define	TPM_CRB_CTRL_CMD_LADDR		0x5C
50 #define	TPM_CRB_CTRL_CMD_HADDR		0x60
51 #define	TPM_CRB_CTRL_RSP_SIZE		0x64
52 #define	TPM_CRB_CTRL_RSP_ADDR		0x68
53 #define	TPM_CRB_CTRL_RSP_HADDR		0x6c
54 #define	TPM_CRB_DATA_BUFFER		0x80
55 
56 #define	TPM_LOC_STATE_ESTB		BIT(0)
57 #define	TPM_LOC_STATE_ASSIGNED		BIT(1)
58 #define	TPM_LOC_STATE_ACTIVE_MASK	0x9C
59 #define	TPM_LOC_STATE_VALID		BIT(7)
60 
61 #define	TPM_CRB_INTF_ID_TYPE_CRB	0x1
62 #define	TPM_CRB_INTF_ID_TYPE		0x7
63 
64 #define	TPM_LOC_CTRL_REQUEST		BIT(0)
65 #define	TPM_LOC_CTRL_RELINQUISH		BIT(1)
66 
67 #define	TPM_CRB_CTRL_REQ_GO_READY	BIT(0)
68 #define	TPM_CRB_CTRL_REQ_GO_IDLE	BIT(1)
69 
70 #define	TPM_CRB_CTRL_STS_ERR_BIT	BIT(0)
71 #define	TPM_CRB_CTRL_STS_IDLE_BIT	BIT(1)
72 
73 #define	TPM_CRB_CTRL_CANCEL_CMD		0x1
74 #define	TPM_CRB_CTRL_CANCEL_CLEAR	0x0
75 
76 #define	TPM_CRB_CTRL_START_CMD		BIT(0)
77 
78 #define	TPM_CRB_INT_ENABLE_BIT		BIT(31)
79 
80 struct tpmcrb_sc {
81 	struct tpm_sc	base;
82 	bus_size_t	cmd_off;
83 	bus_size_t	rsp_off;
84 	size_t		cmd_buf_size;
85 	size_t		rsp_buf_size;
86 };
87 
88 int tpmcrb_transmit(struct tpm_sc *sc, size_t size);
89 
90 static int tpmcrb_acpi_probe(device_t dev);
91 static int tpmcrb_attach(device_t dev);
92 static int tpmcrb_detach(device_t dev);
93 
94 static ACPI_STATUS tpmcrb_fix_buff_offsets(ACPI_RESOURCE *res, void *arg);
95 
96 static bool tpm_wait_for_u32(struct tpm_sc *sc, bus_size_t off,
97     uint32_t mask, uint32_t val, int32_t timeout);
98 static bool tpmcrb_request_locality(struct tpm_sc *sc, int locality);
99 static void tpmcrb_relinquish_locality(struct tpm_sc *sc);
100 static bool tpmcrb_cancel_cmd(struct tpm_sc *sc);
101 
102 char *tpmcrb_ids[] = {"MSFT0101", NULL};
103 
104 static int
105 tpmcrb_acpi_probe(device_t dev)
106 {
107 	int err;
108 	ACPI_TABLE_TPM23 *tbl;
109 	ACPI_STATUS status;
110 	err = ACPI_ID_PROBE(device_get_parent(dev), dev, tpmcrb_ids, NULL);
111 	if (err > 0)
112 		return (err);
113 	/*Find TPM2 Header*/
114 	status = AcpiGetTable(ACPI_SIG_TPM2, 1, (ACPI_TABLE_HEADER **) &tbl);
115 	if(ACPI_FAILURE(status) ||
116 	   tbl->StartMethod != TPM2_START_METHOD_CRB)
117 		err = ENXIO;
118 
119 	device_set_desc(dev, "Trusted Platform Module 2.0, CRB mode");
120 	return (err);
121 }
122 
123 static ACPI_STATUS
124 tpmcrb_fix_buff_offsets(ACPI_RESOURCE *res, void *arg)
125 {
126 	struct tpmcrb_sc *crb_sc;
127 	size_t length;
128 	uint32_t base_addr;
129 
130 	crb_sc = (struct tpmcrb_sc *)arg;
131 
132 	if (res->Type != ACPI_RESOURCE_TYPE_FIXED_MEMORY32)
133 		return (AE_OK);
134 
135 	base_addr = res->Data.FixedMemory32.Address;
136 	length = res->Data.FixedMemory32.AddressLength;
137 
138 	if (crb_sc->cmd_off > base_addr && crb_sc->cmd_off < base_addr + length)
139 		crb_sc->cmd_off -= base_addr;
140 	if (crb_sc->rsp_off > base_addr && crb_sc->rsp_off < base_addr + length)
141 		crb_sc->rsp_off -= base_addr;
142 
143 	return (AE_OK);
144 }
145 
146 static int
147 tpmcrb_attach(device_t dev)
148 {
149 	struct tpmcrb_sc *crb_sc;
150 	struct tpm_sc *sc;
151 	ACPI_HANDLE handle;
152 	ACPI_STATUS status;
153 	int result;
154 
155 	crb_sc = device_get_softc(dev);
156 	sc = &crb_sc->base;
157 	handle = acpi_get_handle(dev);
158 	sc->dev = dev;
159 
160 	sx_init(&sc->dev_lock, "TPM driver lock");
161 	sc->buf = malloc(TPM_BUFSIZE, M_TPM20, M_WAITOK);
162 
163 	sc->mem_rid = 0;
164 	sc->mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &sc->mem_rid,
165 					     RF_ACTIVE);
166 	if (sc->mem_res == NULL) {
167 		tpmcrb_detach(dev);
168 		return (ENXIO);
169 	}
170 
171 	if(!tpmcrb_request_locality(sc, 0)) {
172 		tpmcrb_detach(dev);
173 		return (ENXIO);
174 	}
175 
176 	/*
177 	 * Disable all interrupts for now, since I don't have a device that
178 	 * works in CRB mode and supports them.
179 	 */
180 	AND4(sc, TPM_CRB_INT_ENABLE, ~TPM_CRB_INT_ENABLE_BIT);
181 	sc->interrupts = false;
182 
183 	/*
184 	 * Read addresses of Tx/Rx buffers and their sizes. Note that they
185 	 * can be implemented by a single buffer. Also for some reason CMD
186 	 * addr is stored in two 4 byte neighboring registers, whereas RSP is
187 	 * stored in a single 8 byte one.
188 	 */
189 #ifdef __amd64__
190 	crb_sc->rsp_off = RD8(sc, TPM_CRB_CTRL_RSP_ADDR);
191 #else
192 	crb_sc->rsp_off = RD4(sc, TPM_CRB_CTRL_RSP_ADDR);
193 	crb_sc->rsp_off |= ((uint64_t) RD4(sc, TPM_CRB_CTRL_RSP_HADDR) << 32);
194 #endif
195 	crb_sc->cmd_off = RD4(sc, TPM_CRB_CTRL_CMD_LADDR);
196 	crb_sc->cmd_off |= ((uint64_t) RD4(sc, TPM_CRB_CTRL_CMD_HADDR) << 32);
197 	crb_sc->cmd_buf_size = RD4(sc, TPM_CRB_CTRL_CMD_SIZE);
198 	crb_sc->rsp_buf_size = RD4(sc, TPM_CRB_CTRL_RSP_SIZE);
199 
200 	tpmcrb_relinquish_locality(sc);
201 
202 	/* Emulator returns address in acpi space instead of an offset */
203 	status = AcpiWalkResources(handle, "_CRS", tpmcrb_fix_buff_offsets,
204 		    (void *)crb_sc);
205 	if (ACPI_FAILURE(status)) {
206 		tpmcrb_detach(dev);
207 		return (ENXIO);
208 	}
209 
210 	if (crb_sc->rsp_off == crb_sc->cmd_off) {
211 		/*
212 		 * If Tx/Rx buffers are implemented as one they have to be of
213 		 * same size
214 		 */
215 		if (crb_sc->cmd_buf_size != crb_sc->rsp_buf_size) {
216 			device_printf(sc->dev,
217 			    "Overlapping Tx/Rx buffers have different sizes\n");
218 			tpmcrb_detach(dev);
219 			return (ENXIO);
220 		}
221 	}
222 
223 	sc->transmit = tpmcrb_transmit;
224 
225 	result = tpm20_init(sc);
226 	if (result != 0)
227 		tpmcrb_detach(dev);
228 
229 	return (result);
230 }
231 
232 static int
233 tpmcrb_detach(device_t dev)
234 {
235 	struct tpm_sc *sc;
236 
237 	sc = device_get_softc(dev);
238 	tpm20_release(sc);
239 
240 	if (sc->mem_res != NULL)
241 		bus_release_resource(dev, SYS_RES_MEMORY,
242 		    sc->mem_rid, sc->mem_res);
243 
244 	return (0);
245 }
246 
247 static bool
248 tpm_wait_for_u32(struct tpm_sc *sc, bus_size_t off, uint32_t mask, uint32_t val,
249     int32_t timeout)
250 {
251 
252 	/* Check for condition */
253 	if ((RD4(sc, off) & mask) == val)
254 		return (true);
255 
256 	while (timeout > 0) {
257 		if ((RD4(sc, off) & mask) == val)
258 			return (true);
259 
260 		pause("TPM in polling mode", 1);
261 		timeout -= tick;
262 	}
263 	return (false);
264 }
265 
266 static bool
267 tpmcrb_request_locality(struct tpm_sc *sc, int locality)
268 {
269 	uint32_t mask;
270 
271 	/* Currently we only support Locality 0 */
272 	if (locality != 0)
273 		return (false);
274 
275 	mask = TPM_LOC_STATE_VALID | TPM_LOC_STATE_ASSIGNED;
276 
277 	OR4(sc, TPM_LOC_CTRL, TPM_LOC_CTRL_REQUEST);
278 	if (!tpm_wait_for_u32(sc, TPM_LOC_STATE, mask, mask, TPM_TIMEOUT_C))
279 		return (false);
280 
281 	return (true);
282 }
283 
284 static void
285 tpmcrb_relinquish_locality(struct tpm_sc *sc)
286 {
287 
288 	OR4(sc, TPM_LOC_CTRL, TPM_LOC_CTRL_RELINQUISH);
289 }
290 
291 static bool
292 tpmcrb_cancel_cmd(struct tpm_sc *sc)
293 {
294 	uint32_t mask = ~0;
295 
296 	WR4(sc, TPM_CRB_CTRL_CANCEL, TPM_CRB_CTRL_CANCEL_CMD);
297 	if (!tpm_wait_for_u32(sc, TPM_CRB_CTRL_START,
298 		    mask, ~mask, TPM_TIMEOUT_B)) {
299 		device_printf(sc->dev,
300 		    "Device failed to cancel command\n");
301 		return (false);
302 	}
303 
304 	WR4(sc, TPM_CRB_CTRL_CANCEL, TPM_CRB_CTRL_CANCEL_CLEAR);
305 	return (true);
306 }
307 
308 int
309 tpmcrb_transmit(struct tpm_sc *sc, size_t length)
310 {
311 	struct tpmcrb_sc *crb_sc;
312 	uint32_t mask, curr_cmd;
313 	int timeout, bytes_available;
314 
315 	crb_sc = (struct tpmcrb_sc *)sc;
316 
317 	sx_assert(&sc->dev_lock, SA_XLOCKED);
318 
319 	if (length > crb_sc->cmd_buf_size) {
320 		device_printf(sc->dev,
321 		    "Requested transfer is bigger than buffer size\n");
322 		return (E2BIG);
323 	}
324 
325 	if (RD4(sc, TPM_CRB_CTRL_STS) & TPM_CRB_CTRL_STS_ERR_BIT) {
326 		device_printf(sc->dev,
327 		    "Device has Error bit set\n");
328 		return (EIO);
329 	}
330 	if (!tpmcrb_request_locality(sc, 0)) {
331 		device_printf(sc->dev,
332 		    "Failed to obtain locality\n");
333 		return (EIO);
334 	}
335 	/* Clear cancellation bit */
336 	WR4(sc, TPM_CRB_CTRL_CANCEL, TPM_CRB_CTRL_CANCEL_CLEAR);
337 
338 	/* Switch device to idle state if necessary */
339 	if (!(RD4(sc, TPM_CRB_CTRL_STS) & TPM_CRB_CTRL_STS_IDLE_BIT)) {
340 		OR4(sc, TPM_CRB_CTRL_REQ, TPM_CRB_CTRL_REQ_GO_IDLE);
341 
342 		mask = TPM_CRB_CTRL_STS_IDLE_BIT;
343 		if (!tpm_wait_for_u32(sc, TPM_CRB_CTRL_STS,
344 			    mask, mask, TPM_TIMEOUT_C)) {
345 			device_printf(sc->dev,
346 			    "Failed to transition to idle state\n");
347 			return (EIO);
348 		}
349 	}
350 	/* Switch to ready state */
351 	OR4(sc, TPM_CRB_CTRL_REQ, TPM_CRB_CTRL_REQ_GO_READY);
352 
353 	mask = TPM_CRB_CTRL_REQ_GO_READY;
354 	if (!tpm_wait_for_u32(sc, TPM_CRB_CTRL_STS,
355 		    mask, !mask, TPM_TIMEOUT_C)) {
356 		device_printf(sc->dev,
357 		    "Failed to transition to ready state\n");
358 		return (EIO);
359 	}
360 
361 	/*
362 	 * Calculate timeout for current command.
363 	 * Command code is passed in bytes 6-10.
364 	 */
365 	curr_cmd = be32toh(*(uint32_t *) (&sc->buf[6]));
366 	timeout = tpm20_get_timeout(curr_cmd);
367 
368 	/* Send command and tell device to process it. */
369 	bus_write_region_stream_1(sc->mem_res, crb_sc->cmd_off,
370 	    sc->buf, length);
371 	bus_barrier(sc->mem_res, crb_sc->cmd_off,
372 	    length, BUS_SPACE_BARRIER_WRITE);
373 
374 	WR4(sc, TPM_CRB_CTRL_START, TPM_CRB_CTRL_START_CMD);
375 	bus_barrier(sc->mem_res, TPM_CRB_CTRL_START,
376 	    4, BUS_SPACE_BARRIER_WRITE);
377 
378 	mask = ~0;
379 	if (!tpm_wait_for_u32(sc, TPM_CRB_CTRL_START, mask, ~mask, timeout)) {
380 		device_printf(sc->dev,
381 		    "Timeout while waiting for device to process cmd\n");
382 		if (!tpmcrb_cancel_cmd(sc))
383 			return (EIO);
384 	}
385 
386 	/* Read response header. Length is passed in bytes 2 - 6. */
387 	bus_read_region_stream_1(sc->mem_res, crb_sc->rsp_off,
388 	    sc->buf, TPM_HEADER_SIZE);
389 	bytes_available = be32toh(*(uint32_t *) (&sc->buf[2]));
390 
391 	if (bytes_available > TPM_BUFSIZE || bytes_available < TPM_HEADER_SIZE) {
392 		device_printf(sc->dev,
393 		    "Incorrect response size: %d\n",
394 		    bytes_available);
395 		return (EIO);
396 	}
397 
398 	bus_read_region_stream_1(sc->mem_res, crb_sc->rsp_off + TPM_HEADER_SIZE,
399 	      &sc->buf[TPM_HEADER_SIZE], bytes_available - TPM_HEADER_SIZE);
400 
401 	OR4(sc, TPM_CRB_CTRL_REQ, TPM_CRB_CTRL_REQ_GO_IDLE);
402 
403 	tpmcrb_relinquish_locality(sc);
404 	sc->pending_data_length = bytes_available;
405 
406 	return (0);
407 }
408 
409 /* ACPI Driver */
410 static device_method_t	tpmcrb_methods[] = {
411 	DEVMETHOD(device_probe,		tpmcrb_acpi_probe),
412 	DEVMETHOD(device_attach,	tpmcrb_attach),
413 	DEVMETHOD(device_detach,	tpmcrb_detach),
414 	DEVMETHOD(device_shutdown,	tpm20_shutdown),
415 	DEVMETHOD(device_suspend,	tpm20_suspend),
416 	{0, 0}
417 };
418 static driver_t	tpmcrb_driver = {
419 	"tpmcrb", tpmcrb_methods, sizeof(struct tpmcrb_sc),
420 };
421 
422 devclass_t tpmcrb_devclass;
423 DRIVER_MODULE(tpmcrb, acpi, tpmcrb_driver, tpmcrb_devclass, 0, 0);
424