xref: /freebsd/sys/dev/tpm/tpm_crb.c (revision 8df8b2d3e51d1b816201d8a1fe8bc29fe192e562)
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		BIT(0)
74 
75 #define TPM_CRB_CTRL_START_CMD		BIT(0)
76 
77 #define TPM_CRB_INT_ENABLE_BIT		BIT(31)
78 
79 struct tpmcrb_sc {
80 	struct tpm_sc	base;
81 	bus_size_t	cmd_off;
82 	bus_size_t	rsp_off;
83 	size_t		cmd_buf_size;
84 	size_t		rsp_buf_size;
85 };
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 
159 	sc->dev = dev;
160 
161 	sc->mem_rid = 0;
162 	sc->mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &sc->mem_rid,
163 					     RF_ACTIVE);
164 	if (sc->mem_res == NULL)
165 		return (ENXIO);
166 
167 	if(!tpmcrb_request_locality(sc, 0)) {
168 		tpmcrb_detach(dev);
169 		return (ENXIO);
170 	}
171 
172 	/*
173 	 * Disable all interrupts for now, since I don't have a device that
174 	 * works in CRB mode and supports them.
175 	 */
176 	AND4(sc, TPM_CRB_INT_ENABLE, ~TPM_CRB_INT_ENABLE_BIT);
177 	sc->interrupts = false;
178 
179 	/*
180 	 * Read addresses of Tx/Rx buffers and their sizes. Note that they
181 	 * can be implemented by a single buffer. Also for some reason CMD
182 	 * addr is stored in two 4 byte neighboring registers, whereas RSP is
183 	 * stored in a single 8 byte one.
184 	 */
185 #ifdef __amd64__
186 	crb_sc->rsp_off = RD8(sc, TPM_CRB_CTRL_RSP_ADDR);
187 #else
188 	crb_sc->rsp_off = RD4(sc, TPM_CRB_CTRL_RSP_ADDR);
189 	crb_sc->rsp_off |= ((uint64_t) RD4(sc, TPM_CRB_CTRL_RSP_HADDR) << 32);
190 #endif
191 	crb_sc->cmd_off = RD4(sc, TPM_CRB_CTRL_CMD_LADDR);
192 	crb_sc->cmd_off |= ((uint64_t) RD4(sc, TPM_CRB_CTRL_CMD_HADDR) << 32);
193 	crb_sc->cmd_buf_size = RD4(sc, TPM_CRB_CTRL_CMD_SIZE);
194 	crb_sc->rsp_buf_size = RD4(sc, TPM_CRB_CTRL_RSP_SIZE);
195 
196 	tpmcrb_relinquish_locality(sc);
197 
198 	/* Emulator returns address in acpi space instead of an offset */
199 	status = AcpiWalkResources(handle, "_CRS", tpmcrb_fix_buff_offsets,
200 		    (void *)crb_sc);
201 	if (ACPI_FAILURE(status)) {
202 		tpmcrb_detach(dev);
203 		return (ENXIO);
204 	}
205 
206 	if (crb_sc->rsp_off == crb_sc->cmd_off) {
207 		/*
208 		 * If Tx/Rx buffers are implemented as one they have to be of
209 		 * same size
210 		 */
211 		if (crb_sc->cmd_buf_size != crb_sc->rsp_buf_size) {
212 			device_printf(sc->dev,
213 			    "Overlapping Tx/Rx buffers have different sizes\n");
214 			tpmcrb_detach(dev);
215 			return (ENXIO);
216 		}
217 	}
218 
219 	sc->transmit = tpmcrb_transmit;
220 
221 	result = tpm20_init(sc);
222 	if (result != 0)
223 		tpmcrb_detach(dev);
224 
225 	return (result);
226 }
227 
228 static int
229 tpmcrb_detach(device_t dev)
230 {
231 	struct tpm_sc *sc;
232 
233 	sc = device_get_softc(dev);
234 
235 	if (sc->mem_res != NULL)
236 		bus_release_resource(dev, SYS_RES_MEMORY,
237 		    sc->mem_rid, sc->mem_res);
238 
239 	tpm20_release(sc);
240 	return (0);
241 }
242 
243 static bool
244 tpm_wait_for_u32(struct tpm_sc *sc, bus_size_t off, uint32_t mask, uint32_t val,
245     int32_t timeout)
246 {
247 
248 	/* Check for condition */
249 	if ((RD4(sc, off) & mask) == val)
250 		return (true);
251 
252 	while (timeout > 0) {
253 		if ((RD4(sc, off) & mask) == val)
254 			return (true);
255 
256 		pause("TPM in polling mode", 1);
257 		timeout -= tick;
258 	}
259 	return (false);
260 }
261 
262 static bool
263 tpmcrb_request_locality(struct tpm_sc *sc, int locality)
264 {
265 	uint32_t mask;
266 
267 	/* Currently we only support Locality 0 */
268 	if (locality != 0)
269 		return (false);
270 
271 	mask = TPM_LOC_STATE_VALID | TPM_LOC_STATE_ASSIGNED;
272 
273 	OR4(sc, TPM_LOC_CTRL, TPM_LOC_CTRL_REQUEST);
274 	if (!tpm_wait_for_u32(sc, TPM_LOC_STATE, mask, mask, TPM_TIMEOUT_C))
275 		return (false);
276 
277 	return (true);
278 }
279 
280 static void
281 tpmcrb_relinquish_locality(struct tpm_sc *sc)
282 {
283 
284 	OR4(sc, TPM_LOC_CTRL, TPM_LOC_CTRL_RELINQUISH);
285 }
286 
287 static bool
288 tpmcrb_cancel_cmd(struct tpm_sc *sc)
289 {
290 	uint32_t mask = ~0;
291 
292 	WR4(sc, TPM_CRB_CTRL_CANCEL, TPM_CRB_CTRL_CANCEL_CMD);
293 	if (!tpm_wait_for_u32(sc, TPM_CRB_CTRL_START,
294 		    mask, ~mask, TPM_TIMEOUT_B)) {
295 		device_printf(sc->dev,
296 		    "Device failed to cancel command\n");
297 		return (false);
298 	}
299 
300 	WR4(sc, TPM_CRB_CTRL_CANCEL, !TPM_CRB_CTRL_CANCEL_CMD);
301 	return (true);
302 }
303 
304 int
305 tpmcrb_transmit(struct tpm_sc *sc, size_t length)
306 {
307 	struct tpmcrb_sc *crb_sc;
308 	uint32_t mask, curr_cmd;
309 	int timeout, bytes_available;
310 
311 	crb_sc = (struct tpmcrb_sc *)sc;
312 
313 	sx_assert(&sc->dev_lock, SA_XLOCKED);
314 
315 	if (length > crb_sc->cmd_buf_size) {
316 		device_printf(sc->dev,
317 		    "Requested transfer is bigger than buffer size\n");
318 		return (E2BIG);
319 	}
320 
321 	if (RD4(sc, TPM_CRB_CTRL_STS) & TPM_CRB_CTRL_STS_ERR_BIT) {
322 		device_printf(sc->dev,
323 		    "Device has Error bit set\n");
324 		return (EIO);
325 	}
326 	if (!tpmcrb_request_locality(sc, 0)) {
327 		device_printf(sc->dev,
328 		    "Failed to obtain locality\n");
329 		return (EIO);
330 	}
331 	/* Clear cancellation bit */
332 	WR4(sc, TPM_CRB_CTRL_CANCEL, !TPM_CRB_CTRL_CANCEL_CMD);
333 
334 	/* Switch device to idle state if necessary */
335 	if (!(RD4(sc, TPM_CRB_CTRL_STS) & TPM_CRB_CTRL_STS_IDLE_BIT)) {
336 		OR4(sc, TPM_CRB_CTRL_REQ, TPM_CRB_CTRL_REQ_GO_IDLE);
337 
338 		mask = TPM_CRB_CTRL_STS_IDLE_BIT;
339 		if (!tpm_wait_for_u32(sc, TPM_CRB_CTRL_STS,
340 			    mask, mask, TPM_TIMEOUT_C)) {
341 			device_printf(sc->dev,
342 			    "Failed to transition to idle state\n");
343 			return (EIO);
344 		}
345 	}
346 	/* Switch to ready state */
347 	OR4(sc, TPM_CRB_CTRL_REQ, TPM_CRB_CTRL_REQ_GO_READY);
348 
349 	mask = TPM_CRB_CTRL_REQ_GO_READY;
350 	if (!tpm_wait_for_u32(sc, TPM_CRB_CTRL_STS,
351 		    mask, !mask, TPM_TIMEOUT_C)) {
352 		device_printf(sc->dev,
353 		    "Failed to transition to ready state\n");
354 		return (EIO);
355 	}
356 
357 	/*
358 	 * Calculate timeout for current command.
359 	 * Command code is passed in bytes 6-10.
360 	 */
361 	curr_cmd = be32toh(*(uint32_t *) (&sc->buf[6]));
362 	timeout = tpm20_get_timeout(curr_cmd);
363 
364 	/* Send command and tell device to process it. */
365 	bus_write_region_stream_1(sc->mem_res, crb_sc->cmd_off,
366 	    sc->buf, length);
367 	bus_barrier(sc->mem_res, crb_sc->cmd_off,
368 	    length, BUS_SPACE_BARRIER_WRITE);
369 
370 	WR4(sc, TPM_CRB_CTRL_START, TPM_CRB_CTRL_START_CMD);
371 	bus_barrier(sc->mem_res, TPM_CRB_CTRL_START,
372 	    4, BUS_SPACE_BARRIER_WRITE);
373 
374 	mask = ~0;
375 	if (!tpm_wait_for_u32(sc, TPM_CRB_CTRL_START, mask, ~mask, timeout)) {
376 		device_printf(sc->dev,
377 		    "Timeout while waiting for device to process cmd\n");
378 		if (!tpmcrb_cancel_cmd(sc))
379 			return (EIO);
380 	}
381 
382 	/* Read response header. Length is passed in bytes 2 - 6. */
383 	bus_read_region_stream_1(sc->mem_res, crb_sc->rsp_off,
384 	    sc->buf, TPM_HEADER_SIZE);
385 	bytes_available = be32toh(*(uint32_t *) (&sc->buf[2]));
386 
387 	if (bytes_available > TPM_BUFSIZE || bytes_available < TPM_HEADER_SIZE) {
388 		device_printf(sc->dev,
389 		    "Incorrect response size: %d\n",
390 		    bytes_available);
391 		return (EIO);
392 	}
393 
394 	bus_read_region_stream_1(sc->mem_res, crb_sc->rsp_off + TPM_HEADER_SIZE,
395 	      &sc->buf[TPM_HEADER_SIZE], bytes_available - TPM_HEADER_SIZE);
396 
397 	OR4(sc, TPM_CRB_CTRL_REQ, TPM_CRB_CTRL_REQ_GO_IDLE);
398 
399 	tpmcrb_relinquish_locality(sc);
400 	sc->pending_data_length = bytes_available;
401 
402 	return (0);
403 }
404 
405 /* ACPI Driver */
406 static device_method_t	tpmcrb_methods[] = {
407 	DEVMETHOD(device_probe,		tpmcrb_acpi_probe),
408 	DEVMETHOD(device_attach,	tpmcrb_attach),
409 	DEVMETHOD(device_detach,	tpmcrb_detach),
410 	DEVMETHOD(device_shutdown,	tpm20_shutdown),
411 	DEVMETHOD(device_suspend,	tpm20_suspend),
412 	{0, 0}
413 };
414 static driver_t	tpmcrb_driver = {
415 	"tpmcrb", tpmcrb_methods, sizeof(struct tpmcrb_sc),
416 };
417 
418 devclass_t tpmcrb_devclass;
419 DRIVER_MODULE(tpmcrb, acpi, tpmcrb_driver, tpmcrb_devclass, 0, 0);
420