xref: /openbmc/linux/drivers/char/tpm/tpm_tis.c (revision 06ba8020)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2005, 2006 IBM Corporation
4  * Copyright (C) 2014, 2015 Intel Corporation
5  *
6  * Authors:
7  * Leendert van Doorn <leendert@watson.ibm.com>
8  * Kylene Hall <kjhall@us.ibm.com>
9  *
10  * Maintained by: <tpmdd-devel@lists.sourceforge.net>
11  *
12  * Device driver for TCG/TCPA TPM (trusted platform module).
13  * Specifications at www.trustedcomputinggroup.org
14  *
15  * This device driver implements the TPM interface as defined in
16  * the TCG TPM Interface Spec version 1.2, revision 1.0.
17  */
18 #include <linux/init.h>
19 #include <linux/module.h>
20 #include <linux/moduleparam.h>
21 #include <linux/pnp.h>
22 #include <linux/slab.h>
23 #include <linux/interrupt.h>
24 #include <linux/wait.h>
25 #include <linux/acpi.h>
26 #include <linux/freezer.h>
27 #include <linux/of.h>
28 #include <linux/of_device.h>
29 #include <linux/kernel.h>
30 #include <linux/dmi.h>
31 #include "tpm.h"
32 #include "tpm_tis_core.h"
33 
34 struct tpm_info {
35 	struct resource res;
36 	/* irq > 0 means: use irq $irq;
37 	 * irq = 0 means: autoprobe for an irq;
38 	 * irq = -1 means: no irq support
39 	 */
40 	int irq;
41 };
42 
43 struct tpm_tis_tcg_phy {
44 	struct tpm_tis_data priv;
45 	void __iomem *iobase;
46 };
47 
48 static inline struct tpm_tis_tcg_phy *to_tpm_tis_tcg_phy(struct tpm_tis_data *data)
49 {
50 	return container_of(data, struct tpm_tis_tcg_phy, priv);
51 }
52 
53 #ifdef CONFIG_PREEMPT_RT
54 /*
55  * Flush previous write operations with a dummy read operation to the
56  * TPM MMIO base address.
57  */
58 static inline void tpm_tis_flush(void __iomem *iobase)
59 {
60 	ioread8(iobase + TPM_ACCESS(0));
61 }
62 #else
63 #define tpm_tis_flush(iobase) do { } while (0)
64 #endif
65 
66 /*
67  * Write a byte word to the TPM MMIO address, and flush the write queue.
68  * The flush ensures that the data is sent immediately over the bus and not
69  * aggregated with further requests and transferred later in a batch. The large
70  * write requests can lead to unwanted latency spikes by blocking the CPU until
71  * the complete batch has been transferred.
72  */
73 static inline void tpm_tis_iowrite8(u8 b, void __iomem *iobase, u32 addr)
74 {
75 	iowrite8(b, iobase + addr);
76 	tpm_tis_flush(iobase);
77 }
78 
79 /*
80  * Write a 32-bit word to the TPM MMIO address, and flush the write queue.
81  * The flush ensures that the data is sent immediately over the bus and not
82  * aggregated with further requests and transferred later in a batch. The large
83  * write requests can lead to unwanted latency spikes by blocking the CPU until
84  * the complete batch has been transferred.
85  */
86 static inline void tpm_tis_iowrite32(u32 b, void __iomem *iobase, u32 addr)
87 {
88 	iowrite32(b, iobase + addr);
89 	tpm_tis_flush(iobase);
90 }
91 
92 static int interrupts = -1;
93 module_param(interrupts, int, 0444);
94 MODULE_PARM_DESC(interrupts, "Enable interrupts");
95 
96 static bool itpm;
97 module_param(itpm, bool, 0444);
98 MODULE_PARM_DESC(itpm, "Force iTPM workarounds (found on some Lenovo laptops)");
99 
100 static bool force;
101 #ifdef CONFIG_X86
102 module_param(force, bool, 0444);
103 MODULE_PARM_DESC(force, "Force device probe rather than using ACPI entry");
104 #endif
105 
106 static int tpm_tis_disable_irq(const struct dmi_system_id *d)
107 {
108 	if (interrupts == -1) {
109 		pr_notice("tpm_tis: %s detected: disabling interrupts.\n", d->ident);
110 		interrupts = 0;
111 	}
112 
113 	return 0;
114 }
115 
116 static const struct dmi_system_id tpm_tis_dmi_table[] = {
117 	{
118 		.callback = tpm_tis_disable_irq,
119 		.ident = "ThinkPad T490s",
120 		.matches = {
121 			DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
122 			DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad T490s"),
123 		},
124 	},
125 	{}
126 };
127 
128 #if defined(CONFIG_PNP) && defined(CONFIG_ACPI)
129 static int has_hid(struct acpi_device *dev, const char *hid)
130 {
131 	struct acpi_hardware_id *id;
132 
133 	list_for_each_entry(id, &dev->pnp.ids, list)
134 		if (!strcmp(hid, id->id))
135 			return 1;
136 
137 	return 0;
138 }
139 
140 static inline int is_itpm(struct acpi_device *dev)
141 {
142 	if (!dev)
143 		return 0;
144 	return has_hid(dev, "INTC0102");
145 }
146 #else
147 static inline int is_itpm(struct acpi_device *dev)
148 {
149 	return 0;
150 }
151 #endif
152 
153 #if defined(CONFIG_ACPI)
154 #define DEVICE_IS_TPM2 1
155 
156 static const struct acpi_device_id tpm_acpi_tbl[] = {
157 	{"MSFT0101", DEVICE_IS_TPM2},
158 	{},
159 };
160 MODULE_DEVICE_TABLE(acpi, tpm_acpi_tbl);
161 
162 static int check_acpi_tpm2(struct device *dev)
163 {
164 	const struct acpi_device_id *aid = acpi_match_device(tpm_acpi_tbl, dev);
165 	struct acpi_table_tpm2 *tbl;
166 	acpi_status st;
167 	int ret = 0;
168 
169 	if (!aid || aid->driver_data != DEVICE_IS_TPM2)
170 		return 0;
171 
172 	/* If the ACPI TPM2 signature is matched then a global ACPI_SIG_TPM2
173 	 * table is mandatory
174 	 */
175 	st = acpi_get_table(ACPI_SIG_TPM2, 1, (struct acpi_table_header **)&tbl);
176 	if (ACPI_FAILURE(st) || tbl->header.length < sizeof(*tbl)) {
177 		dev_err(dev, FW_BUG "failed to get TPM2 ACPI table\n");
178 		return -EINVAL;
179 	}
180 
181 	/* The tpm2_crb driver handles this device */
182 	if (tbl->start_method != ACPI_TPM2_MEMORY_MAPPED)
183 		ret = -ENODEV;
184 
185 	acpi_put_table((struct acpi_table_header *)tbl);
186 	return ret;
187 }
188 #else
189 static int check_acpi_tpm2(struct device *dev)
190 {
191 	return 0;
192 }
193 #endif
194 
195 static int tpm_tcg_read_bytes(struct tpm_tis_data *data, u32 addr, u16 len,
196 			      u8 *result, enum tpm_tis_io_mode io_mode)
197 {
198 	struct tpm_tis_tcg_phy *phy = to_tpm_tis_tcg_phy(data);
199 	__le16 result_le16;
200 	__le32 result_le32;
201 
202 	switch (io_mode) {
203 	case TPM_TIS_PHYS_8:
204 		while (len--)
205 			*result++ = ioread8(phy->iobase + addr);
206 		break;
207 	case TPM_TIS_PHYS_16:
208 		result_le16 = cpu_to_le16(ioread16(phy->iobase + addr));
209 		memcpy(result, &result_le16, sizeof(u16));
210 		break;
211 	case TPM_TIS_PHYS_32:
212 		result_le32 = cpu_to_le32(ioread32(phy->iobase + addr));
213 		memcpy(result, &result_le32, sizeof(u32));
214 		break;
215 	}
216 
217 	return 0;
218 }
219 
220 static int tpm_tcg_write_bytes(struct tpm_tis_data *data, u32 addr, u16 len,
221 			       const u8 *value, enum tpm_tis_io_mode io_mode)
222 {
223 	struct tpm_tis_tcg_phy *phy = to_tpm_tis_tcg_phy(data);
224 
225 	switch (io_mode) {
226 	case TPM_TIS_PHYS_8:
227 		while (len--)
228 			tpm_tis_iowrite8(*value++, phy->iobase, addr);
229 		break;
230 	case TPM_TIS_PHYS_16:
231 		return -EINVAL;
232 	case TPM_TIS_PHYS_32:
233 		tpm_tis_iowrite32(le32_to_cpu(*((__le32 *)value)), phy->iobase, addr);
234 		break;
235 	}
236 
237 	return 0;
238 }
239 
240 static const struct tpm_tis_phy_ops tpm_tcg = {
241 	.read_bytes = tpm_tcg_read_bytes,
242 	.write_bytes = tpm_tcg_write_bytes,
243 };
244 
245 static int tpm_tis_init(struct device *dev, struct tpm_info *tpm_info)
246 {
247 	struct tpm_tis_tcg_phy *phy;
248 	int irq = -1;
249 	int rc;
250 
251 	dmi_check_system(tpm_tis_dmi_table);
252 
253 	rc = check_acpi_tpm2(dev);
254 	if (rc)
255 		return rc;
256 
257 	phy = devm_kzalloc(dev, sizeof(struct tpm_tis_tcg_phy), GFP_KERNEL);
258 	if (phy == NULL)
259 		return -ENOMEM;
260 
261 	phy->iobase = devm_ioremap_resource(dev, &tpm_info->res);
262 	if (IS_ERR(phy->iobase))
263 		return PTR_ERR(phy->iobase);
264 
265 	if (interrupts)
266 		irq = tpm_info->irq;
267 
268 	if (itpm || is_itpm(ACPI_COMPANION(dev)))
269 		set_bit(TPM_TIS_ITPM_WORKAROUND, &phy->priv.flags);
270 
271 	return tpm_tis_core_init(dev, &phy->priv, irq, &tpm_tcg,
272 				 ACPI_HANDLE(dev));
273 }
274 
275 static SIMPLE_DEV_PM_OPS(tpm_tis_pm, tpm_pm_suspend, tpm_tis_resume);
276 
277 static int tpm_tis_pnp_init(struct pnp_dev *pnp_dev,
278 			    const struct pnp_device_id *pnp_id)
279 {
280 	struct tpm_info tpm_info = {};
281 	struct resource *res;
282 
283 	res = pnp_get_resource(pnp_dev, IORESOURCE_MEM, 0);
284 	if (!res)
285 		return -ENODEV;
286 	tpm_info.res = *res;
287 
288 	if (pnp_irq_valid(pnp_dev, 0))
289 		tpm_info.irq = pnp_irq(pnp_dev, 0);
290 	else
291 		tpm_info.irq = -1;
292 
293 	return tpm_tis_init(&pnp_dev->dev, &tpm_info);
294 }
295 
296 /*
297  * There is a known bug caused by 93e1b7d42e1e ("[PATCH] tpm: add HID module
298  * parameter"). This commit added IFX0102 device ID, which is also used by
299  * tpm_infineon but ignored to add quirks to probe which driver ought to be
300  * used.
301  */
302 
303 static struct pnp_device_id tpm_pnp_tbl[] = {
304 	{"PNP0C31", 0},		/* TPM */
305 	{"ATM1200", 0},		/* Atmel */
306 	{"IFX0102", 0},		/* Infineon */
307 	{"BCM0101", 0},		/* Broadcom */
308 	{"BCM0102", 0},		/* Broadcom */
309 	{"NSC1200", 0},		/* National */
310 	{"ICO0102", 0},		/* Intel */
311 	/* Add new here */
312 	{"", 0},		/* User Specified */
313 	{"", 0}			/* Terminator */
314 };
315 MODULE_DEVICE_TABLE(pnp, tpm_pnp_tbl);
316 
317 static void tpm_tis_pnp_remove(struct pnp_dev *dev)
318 {
319 	struct tpm_chip *chip = pnp_get_drvdata(dev);
320 
321 	tpm_chip_unregister(chip);
322 	tpm_tis_remove(chip);
323 }
324 
325 static struct pnp_driver tis_pnp_driver = {
326 	.name = "tpm_tis",
327 	.id_table = tpm_pnp_tbl,
328 	.probe = tpm_tis_pnp_init,
329 	.remove = tpm_tis_pnp_remove,
330 	.driver	= {
331 		.pm = &tpm_tis_pm,
332 	},
333 };
334 
335 #define TIS_HID_USR_IDX (ARRAY_SIZE(tpm_pnp_tbl) - 2)
336 module_param_string(hid, tpm_pnp_tbl[TIS_HID_USR_IDX].id,
337 		    sizeof(tpm_pnp_tbl[TIS_HID_USR_IDX].id), 0444);
338 MODULE_PARM_DESC(hid, "Set additional specific HID for this driver to probe");
339 
340 static struct platform_device *force_pdev;
341 
342 static int tpm_tis_plat_probe(struct platform_device *pdev)
343 {
344 	struct tpm_info tpm_info = {};
345 	struct resource *res;
346 
347 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
348 	if (res == NULL) {
349 		dev_err(&pdev->dev, "no memory resource defined\n");
350 		return -ENODEV;
351 	}
352 	tpm_info.res = *res;
353 
354 	tpm_info.irq = platform_get_irq_optional(pdev, 0);
355 	if (tpm_info.irq <= 0) {
356 		if (pdev != force_pdev)
357 			tpm_info.irq = -1;
358 		else
359 			/* When forcing auto probe the IRQ */
360 			tpm_info.irq = 0;
361 	}
362 
363 	return tpm_tis_init(&pdev->dev, &tpm_info);
364 }
365 
366 static void tpm_tis_plat_remove(struct platform_device *pdev)
367 {
368 	struct tpm_chip *chip = dev_get_drvdata(&pdev->dev);
369 
370 	tpm_chip_unregister(chip);
371 	tpm_tis_remove(chip);
372 }
373 
374 #ifdef CONFIG_OF
375 static const struct of_device_id tis_of_platform_match[] = {
376 	{.compatible = "tcg,tpm-tis-mmio"},
377 	{},
378 };
379 MODULE_DEVICE_TABLE(of, tis_of_platform_match);
380 #endif
381 
382 static struct platform_driver tis_drv = {
383 	.probe = tpm_tis_plat_probe,
384 	.remove_new = tpm_tis_plat_remove,
385 	.driver = {
386 		.name		= "tpm_tis",
387 		.pm		= &tpm_tis_pm,
388 		.of_match_table = of_match_ptr(tis_of_platform_match),
389 		.acpi_match_table = ACPI_PTR(tpm_acpi_tbl),
390 	},
391 };
392 
393 static int tpm_tis_force_device(void)
394 {
395 	struct platform_device *pdev;
396 	static const struct resource x86_resources[] = {
397 		DEFINE_RES_MEM(0xFED40000, TIS_MEM_LEN)
398 	};
399 
400 	if (!force)
401 		return 0;
402 
403 	/* The driver core will match the name tpm_tis of the device to
404 	 * the tpm_tis platform driver and complete the setup via
405 	 * tpm_tis_plat_probe
406 	 */
407 	pdev = platform_device_register_simple("tpm_tis", -1, x86_resources,
408 					       ARRAY_SIZE(x86_resources));
409 	if (IS_ERR(pdev))
410 		return PTR_ERR(pdev);
411 	force_pdev = pdev;
412 
413 	return 0;
414 }
415 
416 static int __init init_tis(void)
417 {
418 	int rc;
419 
420 	rc = tpm_tis_force_device();
421 	if (rc)
422 		goto err_force;
423 
424 	rc = platform_driver_register(&tis_drv);
425 	if (rc)
426 		goto err_platform;
427 
428 
429 	if (IS_ENABLED(CONFIG_PNP)) {
430 		rc = pnp_register_driver(&tis_pnp_driver);
431 		if (rc)
432 			goto err_pnp;
433 	}
434 
435 	return 0;
436 
437 err_pnp:
438 	platform_driver_unregister(&tis_drv);
439 err_platform:
440 	if (force_pdev)
441 		platform_device_unregister(force_pdev);
442 err_force:
443 	return rc;
444 }
445 
446 static void __exit cleanup_tis(void)
447 {
448 	pnp_unregister_driver(&tis_pnp_driver);
449 	platform_driver_unregister(&tis_drv);
450 
451 	if (force_pdev)
452 		platform_device_unregister(force_pdev);
453 }
454 
455 module_init(init_tis);
456 module_exit(cleanup_tis);
457 MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");
458 MODULE_DESCRIPTION("TPM Driver");
459 MODULE_VERSION("2.0");
460 MODULE_LICENSE("GPL");
461