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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) Microsoft Corporation
4 *
5 * Implements a firmware TPM as described here:
6 * https://www.microsoft.com/en-us/research/publication/ftpm-software-implementation-tpm-chip/
7 *
8 * A reference implementation is available here:
9 * https://github.com/microsoft/ms-tpm-20-ref/tree/master/Samples/ARM32-FirmwareTPM/optee_ta/fTPM
10 */
11
12#include <linux/acpi.h>
13#include <linux/of.h>
14#include <linux/platform_device.h>
15#include <linux/tee_drv.h>
16#include <linux/tpm.h>
17#include <linux/uuid.h>
18
19#include "tpm.h"
20#include "tpm_ftpm_tee.h"
21
22/*
23 * TA_FTPM_UUID: BC50D971-D4C9-42C4-82CB-343FB7F37896
24 *
25 * Randomly generated, and must correspond to the GUID on the TA side.
26 * Defined here in the reference implementation:
27 * https://github.com/microsoft/ms-tpm-20-ref/blob/master/Samples/ARM32-FirmwareTPM/optee_ta/fTPM/include/fTPM.h#L42
28 */
29static const uuid_t ftpm_ta_uuid =
30 UUID_INIT(0xBC50D971, 0xD4C9, 0x42C4,
31 0x82, 0xCB, 0x34, 0x3F, 0xB7, 0xF3, 0x78, 0x96);
32
33/**
34 * ftpm_tee_tpm_op_recv() - retrieve fTPM response.
35 * @chip: the tpm_chip description as specified in driver/char/tpm/tpm.h.
36 * @buf: the buffer to store data.
37 * @count: the number of bytes to read.
38 *
39 * Return:
40 * In case of success the number of bytes received.
41 * On failure, -errno.
42 */
43static int ftpm_tee_tpm_op_recv(struct tpm_chip *chip, u8 *buf, size_t count)
44{
45 struct ftpm_tee_private *pvt_data = dev_get_drvdata(chip->dev.parent);
46 size_t len;
47
48 len = pvt_data->resp_len;
49 if (count < len) {
50 dev_err(&chip->dev,
51 "%s: Invalid size in recv: count=%zd, resp_len=%zd\n",
52 __func__, count, len);
53 return -EIO;
54 }
55
56 memcpy(buf, pvt_data->resp_buf, len);
57 pvt_data->resp_len = 0;
58
59 return len;
60}
61
62/**
63 * ftpm_tee_tpm_op_send() - send TPM commands through the TEE shared memory.
64 * @chip: the tpm_chip description as specified in driver/char/tpm/tpm.h
65 * @buf: the buffer to send.
66 * @len: the number of bytes to send.
67 *
68 * Return:
69 * In case of success, returns 0.
70 * On failure, -errno
71 */
72static int ftpm_tee_tpm_op_send(struct tpm_chip *chip, u8 *buf, size_t len)
73{
74 struct ftpm_tee_private *pvt_data = dev_get_drvdata(chip->dev.parent);
75 size_t resp_len;
76 int rc;
77 u8 *temp_buf;
78 struct tpm_header *resp_header;
79 struct tee_ioctl_invoke_arg transceive_args;
80 struct tee_param command_params[4];
81 struct tee_shm *shm = pvt_data->shm;
82
83 if (len > MAX_COMMAND_SIZE) {
84 dev_err(&chip->dev,
85 "%s: len=%zd exceeds MAX_COMMAND_SIZE supported by fTPM TA\n",
86 __func__, len);
87 return -EIO;
88 }
89
90 memset(&transceive_args, 0, sizeof(transceive_args));
91 memset(command_params, 0, sizeof(command_params));
92 pvt_data->resp_len = 0;
93
94 /* Invoke FTPM_OPTEE_TA_SUBMIT_COMMAND function of fTPM TA */
95 transceive_args = (struct tee_ioctl_invoke_arg) {
96 .func = FTPM_OPTEE_TA_SUBMIT_COMMAND,
97 .session = pvt_data->session,
98 .num_params = 4,
99 };
100
101 /* Fill FTPM_OPTEE_TA_SUBMIT_COMMAND parameters */
102 command_params[0] = (struct tee_param) {
103 .attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT,
104 .u.memref = {
105 .shm = shm,
106 .size = len,
107 .shm_offs = 0,
108 },
109 };
110
111 temp_buf = tee_shm_get_va(shm, 0);
112 if (IS_ERR(temp_buf)) {
113 dev_err(&chip->dev, "%s: tee_shm_get_va failed for transmit\n",
114 __func__);
115 return PTR_ERR(temp_buf);
116 }
117 memset(temp_buf, 0, (MAX_COMMAND_SIZE + MAX_RESPONSE_SIZE));
118 memcpy(temp_buf, buf, len);
119
120 command_params[1] = (struct tee_param) {
121 .attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT,
122 .u.memref = {
123 .shm = shm,
124 .size = MAX_RESPONSE_SIZE,
125 .shm_offs = MAX_COMMAND_SIZE,
126 },
127 };
128
129 rc = tee_client_invoke_func(pvt_data->ctx, &transceive_args,
130 command_params);
131 if ((rc < 0) || (transceive_args.ret != 0)) {
132 dev_err(&chip->dev, "%s: SUBMIT_COMMAND invoke error: 0x%x\n",
133 __func__, transceive_args.ret);
134 return (rc < 0) ? rc : transceive_args.ret;
135 }
136
137 temp_buf = tee_shm_get_va(shm, command_params[1].u.memref.shm_offs);
138 if (IS_ERR(temp_buf)) {
139 dev_err(&chip->dev, "%s: tee_shm_get_va failed for receive\n",
140 __func__);
141 return PTR_ERR(temp_buf);
142 }
143
144 resp_header = (struct tpm_header *)temp_buf;
145 resp_len = be32_to_cpu(resp_header->length);
146
147 /* sanity check resp_len */
148 if (resp_len < TPM_HEADER_SIZE) {
149 dev_err(&chip->dev, "%s: tpm response header too small\n",
150 __func__);
151 return -EIO;
152 }
153 if (resp_len > MAX_RESPONSE_SIZE) {
154 dev_err(&chip->dev,
155 "%s: resp_len=%zd exceeds MAX_RESPONSE_SIZE\n",
156 __func__, resp_len);
157 return -EIO;
158 }
159
160 /* sanity checks look good, cache the response */
161 memcpy(pvt_data->resp_buf, temp_buf, resp_len);
162 pvt_data->resp_len = resp_len;
163
164 return 0;
165}
166
167static void ftpm_tee_tpm_op_cancel(struct tpm_chip *chip)
168{
169 /* not supported */
170}
171
172static u8 ftpm_tee_tpm_op_status(struct tpm_chip *chip)
173{
174 return 0;
175}
176
177static bool ftpm_tee_tpm_req_canceled(struct tpm_chip *chip, u8 status)
178{
179 return false;
180}
181
182static const struct tpm_class_ops ftpm_tee_tpm_ops = {
183 .flags = TPM_OPS_AUTO_STARTUP,
184 .recv = ftpm_tee_tpm_op_recv,
185 .send = ftpm_tee_tpm_op_send,
186 .cancel = ftpm_tee_tpm_op_cancel,
187 .status = ftpm_tee_tpm_op_status,
188 .req_complete_mask = 0,
189 .req_complete_val = 0,
190 .req_canceled = ftpm_tee_tpm_req_canceled,
191};
192
193/*
194 * Check whether this driver supports the fTPM TA in the TEE instance
195 * represented by the params (ver/data) to this function.
196 */
197static int ftpm_tee_match(struct tee_ioctl_version_data *ver, const void *data)
198{
199 /*
200 * Currently this driver only support GP Complaint OPTEE based fTPM TA
201 */
202 if ((ver->impl_id == TEE_IMPL_ID_OPTEE) &&
203 (ver->gen_caps & TEE_GEN_CAP_GP))
204 return 1;
205 else
206 return 0;
207}
208
209/**
210 * ftpm_tee_probe() - initialize the fTPM
211 * @pdev: the platform_device description.
212 *
213 * Return:
214 * On success, 0. On failure, -errno.
215 */
216static int ftpm_tee_probe(struct device *dev)
217{
218 int rc;
219 struct tpm_chip *chip;
220 struct ftpm_tee_private *pvt_data = NULL;
221 struct tee_ioctl_open_session_arg sess_arg;
222
223 pvt_data = devm_kzalloc(dev, sizeof(struct ftpm_tee_private),
224 GFP_KERNEL);
225 if (!pvt_data)
226 return -ENOMEM;
227
228 dev_set_drvdata(dev, pvt_data);
229
230 /* Open context with TEE driver */
231 pvt_data->ctx = tee_client_open_context(NULL, ftpm_tee_match, NULL,
232 NULL);
233 if (IS_ERR(pvt_data->ctx)) {
234 if (PTR_ERR(pvt_data->ctx) == -ENOENT)
235 return -EPROBE_DEFER;
236 dev_err(dev, "%s: tee_client_open_context failed\n", __func__);
237 return PTR_ERR(pvt_data->ctx);
238 }
239
240 /* Open a session with fTPM TA */
241 memset(&sess_arg, 0, sizeof(sess_arg));
242 export_uuid(sess_arg.uuid, &ftpm_ta_uuid);
243 sess_arg.clnt_login = TEE_IOCTL_LOGIN_PUBLIC;
244 sess_arg.num_params = 0;
245
246 rc = tee_client_open_session(pvt_data->ctx, &sess_arg, NULL);
247 if ((rc < 0) || (sess_arg.ret != 0)) {
248 dev_err(dev, "%s: tee_client_open_session failed, err=%x\n",
249 __func__, sess_arg.ret);
250 rc = -EINVAL;
251 goto out_tee_session;
252 }
253 pvt_data->session = sess_arg.session;
254
255 /* Allocate dynamic shared memory with fTPM TA */
256 pvt_data->shm = tee_shm_alloc_kernel_buf(pvt_data->ctx,
257 MAX_COMMAND_SIZE +
258 MAX_RESPONSE_SIZE);
259 if (IS_ERR(pvt_data->shm)) {
260 dev_err(dev, "%s: tee_shm_alloc_kernel_buf failed\n", __func__);
261 rc = -ENOMEM;
262 goto out_shm_alloc;
263 }
264
265 /* Allocate new struct tpm_chip instance */
266 chip = tpm_chip_alloc(dev, &ftpm_tee_tpm_ops);
267 if (IS_ERR(chip)) {
268 dev_err(dev, "%s: tpm_chip_alloc failed\n", __func__);
269 rc = PTR_ERR(chip);
270 goto out_chip_alloc;
271 }
272
273 pvt_data->chip = chip;
274 pvt_data->chip->flags |= TPM_CHIP_FLAG_TPM2;
275
276 /* Create a character device for the fTPM */
277 rc = tpm_chip_register(pvt_data->chip);
278 if (rc) {
279 dev_err(dev, "%s: tpm_chip_register failed with rc=%d\n",
280 __func__, rc);
281 goto out_chip;
282 }
283
284 return 0;
285
286out_chip:
287 put_device(&pvt_data->chip->dev);
288out_chip_alloc:
289 tee_shm_free(pvt_data->shm);
290out_shm_alloc:
291 tee_client_close_session(pvt_data->ctx, pvt_data->session);
292out_tee_session:
293 tee_client_close_context(pvt_data->ctx);
294
295 return rc;
296}
297
298static int ftpm_plat_tee_probe(struct platform_device *pdev)
299{
300 struct device *dev = &pdev->dev;
301
302 return ftpm_tee_probe(dev);
303}
304
305/**
306 * ftpm_tee_remove() - remove the TPM device
307 * @pdev: the platform_device description.
308 *
309 * Return:
310 * 0 always.
311 */
312static int ftpm_tee_remove(struct device *dev)
313{
314 struct ftpm_tee_private *pvt_data = dev_get_drvdata(dev);
315
316 /* Release the chip */
317 tpm_chip_unregister(pvt_data->chip);
318
319 /* frees chip */
320 put_device(&pvt_data->chip->dev);
321
322 /* Free the shared memory pool */
323 tee_shm_free(pvt_data->shm);
324
325 /* close the existing session with fTPM TA*/
326 tee_client_close_session(pvt_data->ctx, pvt_data->session);
327
328 /* close the context with TEE driver */
329 tee_client_close_context(pvt_data->ctx);
330
331 /* memory allocated with devm_kzalloc() is freed automatically */
332
333 return 0;
334}
335
336static void ftpm_plat_tee_remove(struct platform_device *pdev)
337{
338 struct device *dev = &pdev->dev;
339
340 ftpm_tee_remove(dev);
341}
342
343/**
344 * ftpm_tee_shutdown() - shutdown the TPM device
345 * @pdev: the platform_device description.
346 */
347static void ftpm_plat_tee_shutdown(struct platform_device *pdev)
348{
349 struct ftpm_tee_private *pvt_data = dev_get_drvdata(&pdev->dev);
350
351 tee_shm_free(pvt_data->shm);
352 tee_client_close_session(pvt_data->ctx, pvt_data->session);
353 tee_client_close_context(pvt_data->ctx);
354}
355
356static const struct of_device_id of_ftpm_tee_ids[] = {
357 { .compatible = "microsoft,ftpm" },
358 { }
359};
360MODULE_DEVICE_TABLE(of, of_ftpm_tee_ids);
361
362static struct platform_driver ftpm_tee_plat_driver = {
363 .driver = {
364 .name = "ftpm-tee",
365 .of_match_table = of_match_ptr(of_ftpm_tee_ids),
366 },
367 .shutdown = ftpm_plat_tee_shutdown,
368 .probe = ftpm_plat_tee_probe,
369 .remove_new = ftpm_plat_tee_remove,
370};
371
372/* UUID of the fTPM TA */
373static const struct tee_client_device_id optee_ftpm_id_table[] = {
374 {UUID_INIT(0xbc50d971, 0xd4c9, 0x42c4,
375 0x82, 0xcb, 0x34, 0x3f, 0xb7, 0xf3, 0x78, 0x96)},
376 {}
377};
378
379MODULE_DEVICE_TABLE(tee, optee_ftpm_id_table);
380
381static struct tee_client_driver ftpm_tee_driver = {
382 .id_table = optee_ftpm_id_table,
383 .driver = {
384 .name = "optee-ftpm",
385 .bus = &tee_bus_type,
386 .probe = ftpm_tee_probe,
387 .remove = ftpm_tee_remove,
388 },
389};
390
391static int __init ftpm_mod_init(void)
392{
393 int rc;
394
395 rc = platform_driver_register(&ftpm_tee_plat_driver);
396 if (rc)
397 return rc;
398
399 rc = driver_register(&ftpm_tee_driver.driver);
400 if (rc) {
401 platform_driver_unregister(&ftpm_tee_plat_driver);
402 return rc;
403 }
404
405 return 0;
406}
407
408static void __exit ftpm_mod_exit(void)
409{
410 platform_driver_unregister(&ftpm_tee_plat_driver);
411 driver_unregister(&ftpm_tee_driver.driver);
412}
413
414module_init(ftpm_mod_init);
415module_exit(ftpm_mod_exit);
416
417MODULE_AUTHOR("Thirupathaiah Annapureddy <thiruan@microsoft.com>");
418MODULE_DESCRIPTION("TPM Driver for fTPM TA in TEE");
419MODULE_LICENSE("GPL v2");
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) Microsoft Corporation
4 *
5 * Implements a firmware TPM as described here:
6 * https://www.microsoft.com/en-us/research/publication/ftpm-software-implementation-tpm-chip/
7 *
8 * A reference implementation is available here:
9 * https://github.com/microsoft/ms-tpm-20-ref/tree/master/Samples/ARM32-FirmwareTPM/optee_ta/fTPM
10 */
11
12#include <linux/acpi.h>
13#include <linux/of.h>
14#include <linux/platform_device.h>
15#include <linux/tee_drv.h>
16#include <linux/tpm.h>
17#include <linux/uuid.h>
18
19#include "tpm.h"
20#include "tpm_ftpm_tee.h"
21
22/*
23 * TA_FTPM_UUID: BC50D971-D4C9-42C4-82CB-343FB7F37896
24 *
25 * Randomly generated, and must correspond to the GUID on the TA side.
26 * Defined here in the reference implementation:
27 * https://github.com/microsoft/ms-tpm-20-ref/blob/master/Samples/ARM32-FirmwareTPM/optee_ta/fTPM/include/fTPM.h#L42
28 */
29static const uuid_t ftpm_ta_uuid =
30 UUID_INIT(0xBC50D971, 0xD4C9, 0x42C4,
31 0x82, 0xCB, 0x34, 0x3F, 0xB7, 0xF3, 0x78, 0x96);
32
33/**
34 * ftpm_tee_tpm_op_recv() - retrieve fTPM response.
35 * @chip: the tpm_chip description as specified in driver/char/tpm/tpm.h.
36 * @buf: the buffer to store data.
37 * @count: the number of bytes to read.
38 *
39 * Return:
40 * In case of success the number of bytes received.
41 * On failure, -errno.
42 */
43static int ftpm_tee_tpm_op_recv(struct tpm_chip *chip, u8 *buf, size_t count)
44{
45 struct ftpm_tee_private *pvt_data = dev_get_drvdata(chip->dev.parent);
46 size_t len;
47
48 len = pvt_data->resp_len;
49 if (count < len) {
50 dev_err(&chip->dev,
51 "%s: Invalid size in recv: count=%zd, resp_len=%zd\n",
52 __func__, count, len);
53 return -EIO;
54 }
55
56 memcpy(buf, pvt_data->resp_buf, len);
57 pvt_data->resp_len = 0;
58
59 return len;
60}
61
62/**
63 * ftpm_tee_tpm_op_send() - send TPM commands through the TEE shared memory.
64 * @chip: the tpm_chip description as specified in driver/char/tpm/tpm.h
65 * @buf: the buffer to send.
66 * @len: the number of bytes to send.
67 *
68 * Return:
69 * In case of success, returns 0.
70 * On failure, -errno
71 */
72static int ftpm_tee_tpm_op_send(struct tpm_chip *chip, u8 *buf, size_t len)
73{
74 struct ftpm_tee_private *pvt_data = dev_get_drvdata(chip->dev.parent);
75 size_t resp_len;
76 int rc;
77 u8 *temp_buf;
78 struct tpm_header *resp_header;
79 struct tee_ioctl_invoke_arg transceive_args;
80 struct tee_param command_params[4];
81 struct tee_shm *shm = pvt_data->shm;
82
83 if (len > MAX_COMMAND_SIZE) {
84 dev_err(&chip->dev,
85 "%s: len=%zd exceeds MAX_COMMAND_SIZE supported by fTPM TA\n",
86 __func__, len);
87 return -EIO;
88 }
89
90 memset(&transceive_args, 0, sizeof(transceive_args));
91 memset(command_params, 0, sizeof(command_params));
92 pvt_data->resp_len = 0;
93
94 /* Invoke FTPM_OPTEE_TA_SUBMIT_COMMAND function of fTPM TA */
95 transceive_args = (struct tee_ioctl_invoke_arg) {
96 .func = FTPM_OPTEE_TA_SUBMIT_COMMAND,
97 .session = pvt_data->session,
98 .num_params = 4,
99 };
100
101 /* Fill FTPM_OPTEE_TA_SUBMIT_COMMAND parameters */
102 command_params[0] = (struct tee_param) {
103 .attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT,
104 .u.memref = {
105 .shm = shm,
106 .size = len,
107 .shm_offs = 0,
108 },
109 };
110
111 temp_buf = tee_shm_get_va(shm, 0);
112 if (IS_ERR(temp_buf)) {
113 dev_err(&chip->dev, "%s: tee_shm_get_va failed for transmit\n",
114 __func__);
115 return PTR_ERR(temp_buf);
116 }
117 memset(temp_buf, 0, (MAX_COMMAND_SIZE + MAX_RESPONSE_SIZE));
118 memcpy(temp_buf, buf, len);
119
120 command_params[1] = (struct tee_param) {
121 .attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT,
122 .u.memref = {
123 .shm = shm,
124 .size = MAX_RESPONSE_SIZE,
125 .shm_offs = MAX_COMMAND_SIZE,
126 },
127 };
128
129 rc = tee_client_invoke_func(pvt_data->ctx, &transceive_args,
130 command_params);
131 if ((rc < 0) || (transceive_args.ret != 0)) {
132 dev_err(&chip->dev, "%s: SUBMIT_COMMAND invoke error: 0x%x\n",
133 __func__, transceive_args.ret);
134 return (rc < 0) ? rc : transceive_args.ret;
135 }
136
137 temp_buf = tee_shm_get_va(shm, command_params[1].u.memref.shm_offs);
138 if (IS_ERR(temp_buf)) {
139 dev_err(&chip->dev, "%s: tee_shm_get_va failed for receive\n",
140 __func__);
141 return PTR_ERR(temp_buf);
142 }
143
144 resp_header = (struct tpm_header *)temp_buf;
145 resp_len = be32_to_cpu(resp_header->length);
146
147 /* sanity check resp_len */
148 if (resp_len < TPM_HEADER_SIZE) {
149 dev_err(&chip->dev, "%s: tpm response header too small\n",
150 __func__);
151 return -EIO;
152 }
153 if (resp_len > MAX_RESPONSE_SIZE) {
154 dev_err(&chip->dev,
155 "%s: resp_len=%zd exceeds MAX_RESPONSE_SIZE\n",
156 __func__, resp_len);
157 return -EIO;
158 }
159
160 /* sanity checks look good, cache the response */
161 memcpy(pvt_data->resp_buf, temp_buf, resp_len);
162 pvt_data->resp_len = resp_len;
163
164 return 0;
165}
166
167static void ftpm_tee_tpm_op_cancel(struct tpm_chip *chip)
168{
169 /* not supported */
170}
171
172static u8 ftpm_tee_tpm_op_status(struct tpm_chip *chip)
173{
174 return 0;
175}
176
177static bool ftpm_tee_tpm_req_canceled(struct tpm_chip *chip, u8 status)
178{
179 return false;
180}
181
182static const struct tpm_class_ops ftpm_tee_tpm_ops = {
183 .flags = TPM_OPS_AUTO_STARTUP,
184 .recv = ftpm_tee_tpm_op_recv,
185 .send = ftpm_tee_tpm_op_send,
186 .cancel = ftpm_tee_tpm_op_cancel,
187 .status = ftpm_tee_tpm_op_status,
188 .req_complete_mask = 0,
189 .req_complete_val = 0,
190 .req_canceled = ftpm_tee_tpm_req_canceled,
191};
192
193/*
194 * Check whether this driver supports the fTPM TA in the TEE instance
195 * represented by the params (ver/data) to this function.
196 */
197static int ftpm_tee_match(struct tee_ioctl_version_data *ver, const void *data)
198{
199 /*
200 * Currently this driver only support GP Complaint OPTEE based fTPM TA
201 */
202 if ((ver->impl_id == TEE_IMPL_ID_OPTEE) &&
203 (ver->gen_caps & TEE_GEN_CAP_GP))
204 return 1;
205 else
206 return 0;
207}
208
209/**
210 * ftpm_tee_probe() - initialize the fTPM
211 * @dev: the device description.
212 *
213 * Return:
214 * On success, 0. On failure, -errno.
215 */
216static int ftpm_tee_probe(struct device *dev)
217{
218 int rc;
219 struct tpm_chip *chip;
220 struct ftpm_tee_private *pvt_data = NULL;
221 struct tee_ioctl_open_session_arg sess_arg;
222
223 pvt_data = devm_kzalloc(dev, sizeof(struct ftpm_tee_private),
224 GFP_KERNEL);
225 if (!pvt_data)
226 return -ENOMEM;
227
228 dev_set_drvdata(dev, pvt_data);
229
230 /* Open context with TEE driver */
231 pvt_data->ctx = tee_client_open_context(NULL, ftpm_tee_match, NULL,
232 NULL);
233 if (IS_ERR(pvt_data->ctx)) {
234 if (PTR_ERR(pvt_data->ctx) == -ENOENT)
235 return -EPROBE_DEFER;
236 dev_err(dev, "%s: tee_client_open_context failed\n", __func__);
237 return PTR_ERR(pvt_data->ctx);
238 }
239
240 /* Open a session with fTPM TA */
241 memset(&sess_arg, 0, sizeof(sess_arg));
242 export_uuid(sess_arg.uuid, &ftpm_ta_uuid);
243 sess_arg.clnt_login = TEE_IOCTL_LOGIN_PUBLIC;
244 sess_arg.num_params = 0;
245
246 rc = tee_client_open_session(pvt_data->ctx, &sess_arg, NULL);
247 if ((rc < 0) || (sess_arg.ret != 0)) {
248 dev_err(dev, "%s: tee_client_open_session failed, err=%x\n",
249 __func__, sess_arg.ret);
250 rc = -EINVAL;
251 goto out_tee_session;
252 }
253 pvt_data->session = sess_arg.session;
254
255 /* Allocate dynamic shared memory with fTPM TA */
256 pvt_data->shm = tee_shm_alloc_kernel_buf(pvt_data->ctx,
257 MAX_COMMAND_SIZE +
258 MAX_RESPONSE_SIZE);
259 if (IS_ERR(pvt_data->shm)) {
260 dev_err(dev, "%s: tee_shm_alloc_kernel_buf failed\n", __func__);
261 rc = -ENOMEM;
262 goto out_shm_alloc;
263 }
264
265 /* Allocate new struct tpm_chip instance */
266 chip = tpm_chip_alloc(dev, &ftpm_tee_tpm_ops);
267 if (IS_ERR(chip)) {
268 dev_err(dev, "%s: tpm_chip_alloc failed\n", __func__);
269 rc = PTR_ERR(chip);
270 goto out_chip_alloc;
271 }
272
273 pvt_data->chip = chip;
274 pvt_data->chip->flags |= TPM_CHIP_FLAG_TPM2;
275
276 /* Create a character device for the fTPM */
277 rc = tpm_chip_register(pvt_data->chip);
278 if (rc) {
279 dev_err(dev, "%s: tpm_chip_register failed with rc=%d\n",
280 __func__, rc);
281 goto out_chip;
282 }
283
284 return 0;
285
286out_chip:
287 put_device(&pvt_data->chip->dev);
288out_chip_alloc:
289 tee_shm_free(pvt_data->shm);
290out_shm_alloc:
291 tee_client_close_session(pvt_data->ctx, pvt_data->session);
292out_tee_session:
293 tee_client_close_context(pvt_data->ctx);
294
295 return rc;
296}
297
298static int ftpm_plat_tee_probe(struct platform_device *pdev)
299{
300 struct device *dev = &pdev->dev;
301
302 return ftpm_tee_probe(dev);
303}
304
305/**
306 * ftpm_tee_remove() - remove the TPM device
307 * @dev: the device description.
308 *
309 * Return:
310 * 0 always.
311 */
312static int ftpm_tee_remove(struct device *dev)
313{
314 struct ftpm_tee_private *pvt_data = dev_get_drvdata(dev);
315
316 /* Release the chip */
317 tpm_chip_unregister(pvt_data->chip);
318
319 /* frees chip */
320 put_device(&pvt_data->chip->dev);
321
322 /* Free the shared memory pool */
323 tee_shm_free(pvt_data->shm);
324
325 /* close the existing session with fTPM TA*/
326 tee_client_close_session(pvt_data->ctx, pvt_data->session);
327
328 /* close the context with TEE driver */
329 tee_client_close_context(pvt_data->ctx);
330
331 /* memory allocated with devm_kzalloc() is freed automatically */
332
333 return 0;
334}
335
336static void ftpm_plat_tee_remove(struct platform_device *pdev)
337{
338 struct device *dev = &pdev->dev;
339
340 ftpm_tee_remove(dev);
341}
342
343/**
344 * ftpm_plat_tee_shutdown() - shutdown the TPM device
345 * @pdev: the platform_device description.
346 */
347static void ftpm_plat_tee_shutdown(struct platform_device *pdev)
348{
349 struct ftpm_tee_private *pvt_data = dev_get_drvdata(&pdev->dev);
350
351 tee_shm_free(pvt_data->shm);
352 tee_client_close_session(pvt_data->ctx, pvt_data->session);
353 tee_client_close_context(pvt_data->ctx);
354}
355
356static const struct of_device_id of_ftpm_tee_ids[] = {
357 { .compatible = "microsoft,ftpm" },
358 { }
359};
360MODULE_DEVICE_TABLE(of, of_ftpm_tee_ids);
361
362static struct platform_driver ftpm_tee_plat_driver = {
363 .driver = {
364 .name = "ftpm-tee",
365 .of_match_table = of_match_ptr(of_ftpm_tee_ids),
366 },
367 .shutdown = ftpm_plat_tee_shutdown,
368 .probe = ftpm_plat_tee_probe,
369 .remove = ftpm_plat_tee_remove,
370};
371
372/* UUID of the fTPM TA */
373static const struct tee_client_device_id optee_ftpm_id_table[] = {
374 {UUID_INIT(0xbc50d971, 0xd4c9, 0x42c4,
375 0x82, 0xcb, 0x34, 0x3f, 0xb7, 0xf3, 0x78, 0x96)},
376 {}
377};
378
379MODULE_DEVICE_TABLE(tee, optee_ftpm_id_table);
380
381static struct tee_client_driver ftpm_tee_driver = {
382 .id_table = optee_ftpm_id_table,
383 .driver = {
384 .name = "optee-ftpm",
385 .bus = &tee_bus_type,
386 .probe = ftpm_tee_probe,
387 .remove = ftpm_tee_remove,
388 },
389};
390
391static int __init ftpm_mod_init(void)
392{
393 int rc;
394
395 rc = platform_driver_register(&ftpm_tee_plat_driver);
396 if (rc)
397 return rc;
398
399 rc = driver_register(&ftpm_tee_driver.driver);
400 if (rc) {
401 platform_driver_unregister(&ftpm_tee_plat_driver);
402 return rc;
403 }
404
405 return 0;
406}
407
408static void __exit ftpm_mod_exit(void)
409{
410 platform_driver_unregister(&ftpm_tee_plat_driver);
411 driver_unregister(&ftpm_tee_driver.driver);
412}
413
414module_init(ftpm_mod_init);
415module_exit(ftpm_mod_exit);
416
417MODULE_AUTHOR("Thirupathaiah Annapureddy <thiruan@microsoft.com>");
418MODULE_DESCRIPTION("TPM Driver for fTPM TA in TEE");
419MODULE_LICENSE("GPL v2");