xref: /freebsd/sys/dev/tpm/tpm_crb.c (revision b88cc53d4ddda4486683ee2121f131b10ed21c30)
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 		bus_release_resource(dev, SYS_RES_MEMORY,
169 		    sc->mem_rid, sc->mem_res);
170 		return (ENXIO);
171 	}
172 
173 	/*
174 	 * Disable all interrupts for now, since I don't have a device that
175 	 * works in CRB mode and supports them.
176 	 */
177 	AND4(sc, TPM_CRB_INT_ENABLE, ~TPM_CRB_INT_ENABLE_BIT);
178 	sc->interrupts = false;
179 
180 	/*
181 	 * Read addresses of Tx/Rx buffers and their sizes. Note that they
182 	 * can be implemented by a single buffer. Also for some reason CMD
183 	 * addr is stored in two 4 byte neighboring registers, whereas RSP is
184 	 * stored in a single 8 byte one.
185 	 */
186 #ifdef __amd64__
187 	crb_sc->rsp_off = RD8(sc, TPM_CRB_CTRL_RSP_ADDR);
188 #else
189 	crb_sc->rsp_off = RD4(sc, TPM_CRB_CTRL_RSP_ADDR);
190 	crb_sc->rsp_off |= ((uint64_t) RD4(sc, TPM_CRB_CTRL_RSP_HADDR) << 32);
191 #endif
192 	crb_sc->cmd_off = RD4(sc, TPM_CRB_CTRL_CMD_LADDR);
193 	crb_sc->cmd_off |= ((uint64_t) RD4(sc, TPM_CRB_CTRL_CMD_HADDR) << 32);
194 	crb_sc->cmd_buf_size = RD4(sc, TPM_CRB_CTRL_CMD_SIZE);
195 	crb_sc->rsp_buf_size = RD4(sc, TPM_CRB_CTRL_RSP_SIZE);
196 
197 	tpmcrb_relinquish_locality(sc);
198 
199 	/* Emulator returns address in acpi space instead of an offset */
200 	status = AcpiWalkResources(handle, "_CRS", tpmcrb_fix_buff_offsets,
201 		    (void *)crb_sc);
202 	if (ACPI_FAILURE(status)) {
203 		tpmcrb_detach(dev);
204 		return (ENXIO);
205 	}
206 
207 	if (crb_sc->rsp_off == crb_sc->cmd_off) {
208 		/*
209 		 * If Tx/Rx buffers are implemented as one they have to be of
210 		 * same size
211 		 */
212 		if (crb_sc->cmd_buf_size != crb_sc->rsp_buf_size) {
213 			device_printf(sc->dev,
214 			    "Overlapping Tx/Rx buffers have different sizes\n");
215 			tpmcrb_detach(dev);
216 			return (ENXIO);
217 		}
218 	}
219 
220 	sc->transmit = tpmcrb_transmit;
221 
222 	result = tpm20_init(sc);
223 	if (result != 0)
224 		tpmcrb_detach(dev);
225 
226 	return (result);
227 }
228 
229 static int
230 tpmcrb_detach(device_t dev)
231 {
232 	struct tpm_sc *sc;
233 
234 	sc = device_get_softc(dev);
235 	tpm20_release(sc);
236 
237 	if (sc->mem_res != NULL)
238 		bus_release_resource(dev, SYS_RES_MEMORY,
239 		    sc->mem_rid, sc->mem_res);
240 
241 	return (0);
242 }
243 
244 static bool
245 tpm_wait_for_u32(struct tpm_sc *sc, bus_size_t off, uint32_t mask, uint32_t val,
246     int32_t timeout)
247 {
248 
249 	/* Check for condition */
250 	if ((RD4(sc, off) & mask) == val)
251 		return (true);
252 
253 	while (timeout > 0) {
254 		if ((RD4(sc, off) & mask) == val)
255 			return (true);
256 
257 		pause("TPM in polling mode", 1);
258 		timeout -= tick;
259 	}
260 	return (false);
261 }
262 
263 static bool
264 tpmcrb_request_locality(struct tpm_sc *sc, int locality)
265 {
266 	uint32_t mask;
267 
268 	/* Currently we only support Locality 0 */
269 	if (locality != 0)
270 		return (false);
271 
272 	mask = TPM_LOC_STATE_VALID | TPM_LOC_STATE_ASSIGNED;
273 
274 	OR4(sc, TPM_LOC_CTRL, TPM_LOC_CTRL_REQUEST);
275 	if (!tpm_wait_for_u32(sc, TPM_LOC_STATE, mask, mask, TPM_TIMEOUT_C))
276 		return (false);
277 
278 	return (true);
279 }
280 
281 static void
282 tpmcrb_relinquish_locality(struct tpm_sc *sc)
283 {
284 
285 	OR4(sc, TPM_LOC_CTRL, TPM_LOC_CTRL_RELINQUISH);
286 }
287 
288 static bool
289 tpmcrb_cancel_cmd(struct tpm_sc *sc)
290 {
291 	uint32_t mask = ~0;
292 
293 	WR4(sc, TPM_CRB_CTRL_CANCEL, TPM_CRB_CTRL_CANCEL_CMD);
294 	if (!tpm_wait_for_u32(sc, TPM_CRB_CTRL_START,
295 		    mask, ~mask, TPM_TIMEOUT_B)) {
296 		device_printf(sc->dev,
297 		    "Device failed to cancel command\n");
298 		return (false);
299 	}
300 
301 	WR4(sc, TPM_CRB_CTRL_CANCEL, !TPM_CRB_CTRL_CANCEL_CMD);
302 	return (true);
303 }
304 
305 int
306 tpmcrb_transmit(struct tpm_sc *sc, size_t length)
307 {
308 	struct tpmcrb_sc *crb_sc;
309 	uint32_t mask, curr_cmd;
310 	int timeout, bytes_available;
311 
312 	crb_sc = (struct tpmcrb_sc *)sc;
313 
314 	sx_assert(&sc->dev_lock, SA_XLOCKED);
315 
316 	if (length > crb_sc->cmd_buf_size) {
317 		device_printf(sc->dev,
318 		    "Requested transfer is bigger than buffer size\n");
319 		return (E2BIG);
320 	}
321 
322 	if (RD4(sc, TPM_CRB_CTRL_STS) & TPM_CRB_CTRL_STS_ERR_BIT) {
323 		device_printf(sc->dev,
324 		    "Device has Error bit set\n");
325 		return (EIO);
326 	}
327 	if (!tpmcrb_request_locality(sc, 0)) {
328 		device_printf(sc->dev,
329 		    "Failed to obtain locality\n");
330 		return (EIO);
331 	}
332 	/* Clear cancellation bit */
333 	WR4(sc, TPM_CRB_CTRL_CANCEL, !TPM_CRB_CTRL_CANCEL_CMD);
334 
335 	/* Switch device to idle state if necessary */
336 	if (!(RD4(sc, TPM_CRB_CTRL_STS) & TPM_CRB_CTRL_STS_IDLE_BIT)) {
337 		OR4(sc, TPM_CRB_CTRL_REQ, TPM_CRB_CTRL_REQ_GO_IDLE);
338 
339 		mask = TPM_CRB_CTRL_STS_IDLE_BIT;
340 		if (!tpm_wait_for_u32(sc, TPM_CRB_CTRL_STS,
341 			    mask, mask, TPM_TIMEOUT_C)) {
342 			device_printf(sc->dev,
343 			    "Failed to transition to idle state\n");
344 			return (EIO);
345 		}
346 	}
347 	/* Switch to ready state */
348 	OR4(sc, TPM_CRB_CTRL_REQ, TPM_CRB_CTRL_REQ_GO_READY);
349 
350 	mask = TPM_CRB_CTRL_REQ_GO_READY;
351 	if (!tpm_wait_for_u32(sc, TPM_CRB_CTRL_STS,
352 		    mask, !mask, TPM_TIMEOUT_C)) {
353 		device_printf(sc->dev,
354 		    "Failed to transition to ready state\n");
355 		return (EIO);
356 	}
357 
358 	/*
359 	 * Calculate timeout for current command.
360 	 * Command code is passed in bytes 6-10.
361 	 */
362 	curr_cmd = be32toh(*(uint32_t *) (&sc->buf[6]));
363 	timeout = tpm20_get_timeout(curr_cmd);
364 
365 	/* Send command and tell device to process it. */
366 	bus_write_region_stream_1(sc->mem_res, crb_sc->cmd_off,
367 	    sc->buf, length);
368 	bus_barrier(sc->mem_res, crb_sc->cmd_off,
369 	    length, BUS_SPACE_BARRIER_WRITE);
370 
371 	WR4(sc, TPM_CRB_CTRL_START, TPM_CRB_CTRL_START_CMD);
372 	bus_barrier(sc->mem_res, TPM_CRB_CTRL_START,
373 	    4, BUS_SPACE_BARRIER_WRITE);
374 
375 	mask = ~0;
376 	if (!tpm_wait_for_u32(sc, TPM_CRB_CTRL_START, mask, ~mask, timeout)) {
377 		device_printf(sc->dev,
378 		    "Timeout while waiting for device to process cmd\n");
379 		if (!tpmcrb_cancel_cmd(sc))
380 			return (EIO);
381 	}
382 
383 	/* Read response header. Length is passed in bytes 2 - 6. */
384 	bus_read_region_stream_1(sc->mem_res, crb_sc->rsp_off,
385 	    sc->buf, TPM_HEADER_SIZE);
386 	bytes_available = be32toh(*(uint32_t *) (&sc->buf[2]));
387 
388 	if (bytes_available > TPM_BUFSIZE || bytes_available < TPM_HEADER_SIZE) {
389 		device_printf(sc->dev,
390 		    "Incorrect response size: %d\n",
391 		    bytes_available);
392 		return (EIO);
393 	}
394 
395 	bus_read_region_stream_1(sc->mem_res, crb_sc->rsp_off + TPM_HEADER_SIZE,
396 	      &sc->buf[TPM_HEADER_SIZE], bytes_available - TPM_HEADER_SIZE);
397 
398 	OR4(sc, TPM_CRB_CTRL_REQ, TPM_CRB_CTRL_REQ_GO_IDLE);
399 
400 	tpmcrb_relinquish_locality(sc);
401 	sc->pending_data_length = bytes_available;
402 
403 	return (0);
404 }
405 
406 /* ACPI Driver */
407 static device_method_t	tpmcrb_methods[] = {
408 	DEVMETHOD(device_probe,		tpmcrb_acpi_probe),
409 	DEVMETHOD(device_attach,	tpmcrb_attach),
410 	DEVMETHOD(device_detach,	tpmcrb_detach),
411 	DEVMETHOD(device_shutdown,	tpm20_shutdown),
412 	DEVMETHOD(device_suspend,	tpm20_suspend),
413 	{0, 0}
414 };
415 static driver_t	tpmcrb_driver = {
416 	"tpmcrb", tpmcrb_methods, sizeof(struct tpmcrb_sc),
417 };
418 
419 devclass_t tpmcrb_devclass;
420 DRIVER_MODULE(tpmcrb, acpi, tpmcrb_driver, tpmcrb_devclass, 0, 0);
421