1 /*
2 * Copyright (C) 2014 Intel Corporation
3 *
4 * Authors:
5 * Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
6 *
7 * Maintained by: <tpmdd-devel@lists.sourceforge.net>
8 *
9 * This device driver implements the TPM interface as defined in
10 * the TCG CRB 2.0 TPM specification.
11 *
12 * This program is free software; you can redistribute it and/or
13 * modify it under the terms of the GNU General Public License
14 * as published by the Free Software Foundation; version 2
15 * of the License.
16 */
17
18 #include <linux/acpi.h>
19 #include <linux/highmem.h>
20 #include <linux/rculist.h>
21 #include <linux/module.h>
22 #include <linux/platform_device.h>
23 #include "tpm.h"
24
25 #define ACPI_SIG_TPM2 "TPM2"
26
27 static const u8 CRB_ACPI_START_UUID[] = {
28 /* 0000 */ 0xAB, 0x6C, 0xBF, 0x6B, 0x63, 0x54, 0x14, 0x47,
29 /* 0008 */ 0xB7, 0xCD, 0xF0, 0x20, 0x3C, 0x03, 0x68, 0xD4
30 };
31
32 enum crb_defaults {
33 CRB_ACPI_START_REVISION_ID = 1,
34 CRB_ACPI_START_INDEX = 1,
35 };
36
37 struct acpi_tpm2 {
38 struct acpi_table_header hdr;
39 u16 platform_class;
40 u16 reserved;
41 u64 control_area_pa;
42 u32 start_method;
43 } __packed;
44
45 enum crb_ca_request {
46 CRB_CA_REQ_GO_IDLE = BIT(0),
47 CRB_CA_REQ_CMD_READY = BIT(1),
48 };
49
50 enum crb_ca_status {
51 CRB_CA_STS_ERROR = BIT(0),
52 CRB_CA_STS_TPM_IDLE = BIT(1),
53 };
54
55 enum crb_start {
56 CRB_START_INVOKE = BIT(0),
57 };
58
59 enum crb_cancel {
60 CRB_CANCEL_INVOKE = BIT(0),
61 };
62
63 struct crb_control_area {
64 u32 req;
65 u32 sts;
66 u32 cancel;
67 u32 start;
68 u32 int_enable;
69 u32 int_sts;
70 u32 cmd_size;
71 u64 cmd_pa;
72 u32 rsp_size;
73 u64 rsp_pa;
74 } __packed;
75
76 enum crb_status {
77 CRB_STS_COMPLETE = BIT(0),
78 };
79
80 enum crb_flags {
81 CRB_FL_ACPI_START = BIT(0),
82 CRB_FL_CRB_START = BIT(1),
83 };
84
85 struct crb_priv {
86 unsigned int flags;
87 struct crb_control_area __iomem *cca;
88 u8 __iomem *cmd;
89 u8 __iomem *rsp;
90 };
91
92 static SIMPLE_DEV_PM_OPS(crb_pm, tpm_pm_suspend, tpm_pm_resume);
93
crb_status(struct tpm_chip * chip)94 static u8 crb_status(struct tpm_chip *chip)
95 {
96 struct crb_priv *priv = chip->vendor.priv;
97 u8 sts = 0;
98
99 if ((le32_to_cpu(ioread32(&priv->cca->start)) & CRB_START_INVOKE) !=
100 CRB_START_INVOKE)
101 sts |= CRB_STS_COMPLETE;
102
103 return sts;
104 }
105
crb_recv(struct tpm_chip * chip,u8 * buf,size_t count)106 static int crb_recv(struct tpm_chip *chip, u8 *buf, size_t count)
107 {
108 struct crb_priv *priv = chip->vendor.priv;
109 unsigned int expected;
110
111 /* sanity check */
112 if (count < 6)
113 return -EIO;
114
115 if (le32_to_cpu(ioread32(&priv->cca->sts)) & CRB_CA_STS_ERROR)
116 return -EIO;
117
118 memcpy_fromio(buf, priv->rsp, 6);
119 expected = be32_to_cpup((__be32 *) &buf[2]);
120
121 if (expected > count)
122 return -EIO;
123
124 memcpy_fromio(&buf[6], &priv->rsp[6], expected - 6);
125
126 return expected;
127 }
128
crb_do_acpi_start(struct tpm_chip * chip)129 static int crb_do_acpi_start(struct tpm_chip *chip)
130 {
131 union acpi_object *obj;
132 int rc;
133
134 obj = acpi_evaluate_dsm(chip->acpi_dev_handle,
135 CRB_ACPI_START_UUID,
136 CRB_ACPI_START_REVISION_ID,
137 CRB_ACPI_START_INDEX,
138 NULL);
139 if (!obj)
140 return -ENXIO;
141 rc = obj->integer.value == 0 ? 0 : -ENXIO;
142 ACPI_FREE(obj);
143 return rc;
144 }
145
crb_send(struct tpm_chip * chip,u8 * buf,size_t len)146 static int crb_send(struct tpm_chip *chip, u8 *buf, size_t len)
147 {
148 struct crb_priv *priv = chip->vendor.priv;
149 int rc = 0;
150
151 if (len > le32_to_cpu(ioread32(&priv->cca->cmd_size))) {
152 dev_err(&chip->dev,
153 "invalid command count value %x %zx\n",
154 (unsigned int) len,
155 (size_t) le32_to_cpu(ioread32(&priv->cca->cmd_size)));
156 return -E2BIG;
157 }
158
159 memcpy_toio(priv->cmd, buf, len);
160
161 /* Make sure that cmd is populated before issuing start. */
162 wmb();
163
164 if (priv->flags & CRB_FL_CRB_START)
165 iowrite32(cpu_to_le32(CRB_START_INVOKE), &priv->cca->start);
166
167 if (priv->flags & CRB_FL_ACPI_START)
168 rc = crb_do_acpi_start(chip);
169
170 return rc;
171 }
172
crb_cancel(struct tpm_chip * chip)173 static void crb_cancel(struct tpm_chip *chip)
174 {
175 struct crb_priv *priv = chip->vendor.priv;
176
177 iowrite32(cpu_to_le32(CRB_CANCEL_INVOKE), &priv->cca->cancel);
178
179 /* Make sure that cmd is populated before issuing cancel. */
180 wmb();
181
182 if ((priv->flags & CRB_FL_ACPI_START) && crb_do_acpi_start(chip))
183 dev_err(&chip->dev, "ACPI Start failed\n");
184
185 iowrite32(0, &priv->cca->cancel);
186 }
187
crb_req_canceled(struct tpm_chip * chip,u8 status)188 static bool crb_req_canceled(struct tpm_chip *chip, u8 status)
189 {
190 struct crb_priv *priv = chip->vendor.priv;
191 u32 cancel = le32_to_cpu(ioread32(&priv->cca->cancel));
192
193 return (cancel & CRB_CANCEL_INVOKE) == CRB_CANCEL_INVOKE;
194 }
195
196 static const struct tpm_class_ops tpm_crb = {
197 .status = crb_status,
198 .recv = crb_recv,
199 .send = crb_send,
200 .cancel = crb_cancel,
201 .req_canceled = crb_req_canceled,
202 .req_complete_mask = CRB_STS_COMPLETE,
203 .req_complete_val = CRB_STS_COMPLETE,
204 };
205
crb_acpi_add(struct acpi_device * device)206 static int crb_acpi_add(struct acpi_device *device)
207 {
208 struct tpm_chip *chip;
209 struct acpi_tpm2 *buf;
210 struct crb_priv *priv;
211 struct device *dev = &device->dev;
212 acpi_status status;
213 u32 sm;
214 u64 pa;
215 int rc;
216
217 status = acpi_get_table(ACPI_SIG_TPM2, 1,
218 (struct acpi_table_header **) &buf);
219 if (ACPI_FAILURE(status)) {
220 dev_err(dev, "failed to get TPM2 ACPI table\n");
221 return -ENODEV;
222 }
223
224 /* Should the FIFO driver handle this? */
225 if (buf->start_method == TPM2_START_FIFO)
226 return -ENODEV;
227
228 chip = tpmm_chip_alloc(dev, &tpm_crb);
229 if (IS_ERR(chip))
230 return PTR_ERR(chip);
231
232 chip->flags = TPM_CHIP_FLAG_TPM2;
233
234 if (buf->hdr.length < sizeof(struct acpi_tpm2)) {
235 dev_err(dev, "TPM2 ACPI table has wrong size");
236 return -EINVAL;
237 }
238
239 priv = (struct crb_priv *) devm_kzalloc(dev, sizeof(struct crb_priv),
240 GFP_KERNEL);
241 if (!priv) {
242 dev_err(dev, "failed to devm_kzalloc for private data\n");
243 return -ENOMEM;
244 }
245
246 sm = le32_to_cpu(buf->start_method);
247
248 /* The reason for the extra quirk is that the PTT in 4th Gen Core CPUs
249 * report only ACPI start but in practice seems to require both
250 * ACPI start and CRB start.
251 */
252 if (sm == TPM2_START_CRB || sm == TPM2_START_FIFO ||
253 !strcmp(acpi_device_hid(device), "MSFT0101"))
254 priv->flags |= CRB_FL_CRB_START;
255
256 if (sm == TPM2_START_ACPI || sm == TPM2_START_CRB_WITH_ACPI)
257 priv->flags |= CRB_FL_ACPI_START;
258
259 priv->cca = (struct crb_control_area __iomem *)
260 devm_ioremap_nocache(dev, buf->control_area_pa, 0x1000);
261 if (!priv->cca) {
262 dev_err(dev, "ioremap of the control area failed\n");
263 return -ENOMEM;
264 }
265
266 memcpy_fromio(&pa, &priv->cca->cmd_pa, 8);
267 pa = le64_to_cpu(pa);
268 priv->cmd = devm_ioremap_nocache(dev, pa,
269 ioread32(&priv->cca->cmd_size));
270 if (!priv->cmd) {
271 dev_err(dev, "ioremap of the command buffer failed\n");
272 return -ENOMEM;
273 }
274
275 memcpy_fromio(&pa, &priv->cca->rsp_pa, 8);
276 pa = le64_to_cpu(pa);
277 priv->rsp = devm_ioremap_nocache(dev, pa,
278 ioread32(&priv->cca->rsp_size));
279 if (!priv->rsp) {
280 dev_err(dev, "ioremap of the response buffer failed\n");
281 return -ENOMEM;
282 }
283
284 chip->vendor.priv = priv;
285
286 /* Default timeouts and durations */
287 chip->vendor.timeout_a = msecs_to_jiffies(TPM2_TIMEOUT_A);
288 chip->vendor.timeout_b = msecs_to_jiffies(TPM2_TIMEOUT_B);
289 chip->vendor.timeout_c = msecs_to_jiffies(TPM2_TIMEOUT_C);
290 chip->vendor.timeout_d = msecs_to_jiffies(TPM2_TIMEOUT_D);
291 chip->vendor.duration[TPM_SHORT] =
292 msecs_to_jiffies(TPM2_DURATION_SHORT);
293 chip->vendor.duration[TPM_MEDIUM] =
294 msecs_to_jiffies(TPM2_DURATION_MEDIUM);
295 chip->vendor.duration[TPM_LONG] =
296 msecs_to_jiffies(TPM2_DURATION_LONG);
297
298 chip->acpi_dev_handle = device->handle;
299
300 rc = tpm2_do_selftest(chip);
301 if (rc)
302 return rc;
303
304 return tpm_chip_register(chip);
305 }
306
crb_acpi_remove(struct acpi_device * device)307 static int crb_acpi_remove(struct acpi_device *device)
308 {
309 struct device *dev = &device->dev;
310 struct tpm_chip *chip = dev_get_drvdata(dev);
311
312 if (chip->flags & TPM_CHIP_FLAG_TPM2)
313 tpm2_shutdown(chip, TPM2_SU_CLEAR);
314
315 tpm_chip_unregister(chip);
316
317 return 0;
318 }
319
320 static struct acpi_device_id crb_device_ids[] = {
321 {"MSFT0101", 0},
322 {"", 0},
323 };
324 MODULE_DEVICE_TABLE(acpi, crb_device_ids);
325
326 static struct acpi_driver crb_acpi_driver = {
327 .name = "tpm_crb",
328 .ids = crb_device_ids,
329 .ops = {
330 .add = crb_acpi_add,
331 .remove = crb_acpi_remove,
332 },
333 .drv = {
334 .pm = &crb_pm,
335 },
336 };
337
338 module_acpi_driver(crb_acpi_driver);
339 MODULE_AUTHOR("Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>");
340 MODULE_DESCRIPTION("TPM2 Driver");
341 MODULE_VERSION("0.1");
342 MODULE_LICENSE("GPL");
343