xref: /openbmc/linux/drivers/char/tpm/tpm_tis.c (revision ae36453a)
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/kernel.h>
29 #include <linux/dmi.h>
30 #include "tpm.h"
31 #include "tpm_tis_core.h"
32 
33 struct tpm_info {
34 	struct resource res;
35 	/* irq > 0 means: use irq $irq;
36 	 * irq = 0 means: autoprobe for an irq;
37 	 * irq = -1 means: no irq support
38 	 */
39 	int irq;
40 };
41 
42 struct tpm_tis_tcg_phy {
43 	struct tpm_tis_data priv;
44 	void __iomem *iobase;
45 };
46 
47 static inline struct tpm_tis_tcg_phy *to_tpm_tis_tcg_phy(struct tpm_tis_data *data)
48 {
49 	return container_of(data, struct tpm_tis_tcg_phy, priv);
50 }
51 
52 #ifdef CONFIG_PREEMPT_RT
53 /*
54  * Flush previous write operations with a dummy read operation to the
55  * TPM MMIO base address.
56  */
57 static inline void tpm_tis_flush(void __iomem *iobase)
58 {
59 	ioread8(iobase + TPM_ACCESS(0));
60 }
61 #else
62 #define tpm_tis_flush(iobase) do { } while (0)
63 #endif
64 
65 /*
66  * Write a byte word to the TPM MMIO address, and flush the write queue.
67  * The flush ensures that the data is sent immediately over the bus and not
68  * aggregated with further requests and transferred later in a batch. The large
69  * write requests can lead to unwanted latency spikes by blocking the CPU until
70  * the complete batch has been transferred.
71  */
72 static inline void tpm_tis_iowrite8(u8 b, void __iomem *iobase, u32 addr)
73 {
74 	iowrite8(b, iobase + addr);
75 	tpm_tis_flush(iobase);
76 }
77 
78 /*
79  * Write a 32-bit word to the TPM MMIO address, and flush the write queue.
80  * The flush ensures that the data is sent immediately over the bus and not
81  * aggregated with further requests and transferred later in a batch. The large
82  * write requests can lead to unwanted latency spikes by blocking the CPU until
83  * the complete batch has been transferred.
84  */
85 static inline void tpm_tis_iowrite32(u32 b, void __iomem *iobase, u32 addr)
86 {
87 	iowrite32(b, iobase + addr);
88 	tpm_tis_flush(iobase);
89 }
90 
91 static int interrupts = -1;
92 module_param(interrupts, int, 0444);
93 MODULE_PARM_DESC(interrupts, "Enable interrupts");
94 
95 static bool itpm;
96 module_param(itpm, bool, 0444);
97 MODULE_PARM_DESC(itpm, "Force iTPM workarounds (found on some Lenovo laptops)");
98 
99 static bool force;
100 #ifdef CONFIG_X86
101 module_param(force, bool, 0444);
102 MODULE_PARM_DESC(force, "Force device probe rather than using ACPI entry");
103 #endif
104 
105 static int tpm_tis_disable_irq(const struct dmi_system_id *d)
106 {
107 	if (interrupts == -1) {
108 		pr_notice("tpm_tis: %s detected: disabling interrupts.\n", d->ident);
109 		interrupts = 0;
110 	}
111 
112 	return 0;
113 }
114 
115 static const struct dmi_system_id tpm_tis_dmi_table[] = {
116 	{
117 		.callback = tpm_tis_disable_irq,
118 		.ident = "ThinkPad T490s",
119 		.matches = {
120 			DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
121 			DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad T490s"),
122 		},
123 	},
124 	{
125 		.callback = tpm_tis_disable_irq,
126 		.ident = "ThinkStation P360 Tiny",
127 		.matches = {
128 			DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
129 			DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkStation P360 Tiny"),
130 		},
131 	},
132 	{
133 		.callback = tpm_tis_disable_irq,
134 		.ident = "ThinkPad L490",
135 		.matches = {
136 			DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
137 			DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad L490"),
138 		},
139 	},
140 	{
141 		.callback = tpm_tis_disable_irq,
142 		.ident = "UPX-TGL",
143 		.matches = {
144 			DMI_MATCH(DMI_SYS_VENDOR, "AAEON"),
145 		},
146 	},
147 	{}
148 };
149 
150 #if defined(CONFIG_PNP) && defined(CONFIG_ACPI)
151 static int has_hid(struct acpi_device *dev, const char *hid)
152 {
153 	struct acpi_hardware_id *id;
154 
155 	list_for_each_entry(id, &dev->pnp.ids, list)
156 		if (!strcmp(hid, id->id))
157 			return 1;
158 
159 	return 0;
160 }
161 
162 static inline int is_itpm(struct acpi_device *dev)
163 {
164 	if (!dev)
165 		return 0;
166 	return has_hid(dev, "INTC0102");
167 }
168 #else
169 static inline int is_itpm(struct acpi_device *dev)
170 {
171 	return 0;
172 }
173 #endif
174 
175 #if defined(CONFIG_ACPI)
176 #define DEVICE_IS_TPM2 1
177 
178 static const struct acpi_device_id tpm_acpi_tbl[] = {
179 	{"MSFT0101", DEVICE_IS_TPM2},
180 	{},
181 };
182 MODULE_DEVICE_TABLE(acpi, tpm_acpi_tbl);
183 
184 static int check_acpi_tpm2(struct device *dev)
185 {
186 	const struct acpi_device_id *aid = acpi_match_device(tpm_acpi_tbl, dev);
187 	struct acpi_table_tpm2 *tbl;
188 	acpi_status st;
189 	int ret = 0;
190 
191 	if (!aid || aid->driver_data != DEVICE_IS_TPM2)
192 		return 0;
193 
194 	/* If the ACPI TPM2 signature is matched then a global ACPI_SIG_TPM2
195 	 * table is mandatory
196 	 */
197 	st = acpi_get_table(ACPI_SIG_TPM2, 1, (struct acpi_table_header **)&tbl);
198 	if (ACPI_FAILURE(st) || tbl->header.length < sizeof(*tbl)) {
199 		dev_err(dev, FW_BUG "failed to get TPM2 ACPI table\n");
200 		return -EINVAL;
201 	}
202 
203 	/* The tpm2_crb driver handles this device */
204 	if (tbl->start_method != ACPI_TPM2_MEMORY_MAPPED)
205 		ret = -ENODEV;
206 
207 	acpi_put_table((struct acpi_table_header *)tbl);
208 	return ret;
209 }
210 #else
211 static int check_acpi_tpm2(struct device *dev)
212 {
213 	return 0;
214 }
215 #endif
216 
217 static int tpm_tcg_read_bytes(struct tpm_tis_data *data, u32 addr, u16 len,
218 			      u8 *result, enum tpm_tis_io_mode io_mode)
219 {
220 	struct tpm_tis_tcg_phy *phy = to_tpm_tis_tcg_phy(data);
221 	__le16 result_le16;
222 	__le32 result_le32;
223 
224 	switch (io_mode) {
225 	case TPM_TIS_PHYS_8:
226 		while (len--)
227 			*result++ = ioread8(phy->iobase + addr);
228 		break;
229 	case TPM_TIS_PHYS_16:
230 		result_le16 = cpu_to_le16(ioread16(phy->iobase + addr));
231 		memcpy(result, &result_le16, sizeof(u16));
232 		break;
233 	case TPM_TIS_PHYS_32:
234 		result_le32 = cpu_to_le32(ioread32(phy->iobase + addr));
235 		memcpy(result, &result_le32, sizeof(u32));
236 		break;
237 	}
238 
239 	return 0;
240 }
241 
242 static int tpm_tcg_write_bytes(struct tpm_tis_data *data, u32 addr, u16 len,
243 			       const u8 *value, enum tpm_tis_io_mode io_mode)
244 {
245 	struct tpm_tis_tcg_phy *phy = to_tpm_tis_tcg_phy(data);
246 
247 	switch (io_mode) {
248 	case TPM_TIS_PHYS_8:
249 		while (len--)
250 			tpm_tis_iowrite8(*value++, phy->iobase, addr);
251 		break;
252 	case TPM_TIS_PHYS_16:
253 		return -EINVAL;
254 	case TPM_TIS_PHYS_32:
255 		tpm_tis_iowrite32(le32_to_cpu(*((__le32 *)value)), phy->iobase, addr);
256 		break;
257 	}
258 
259 	return 0;
260 }
261 
262 static const struct tpm_tis_phy_ops tpm_tcg = {
263 	.read_bytes = tpm_tcg_read_bytes,
264 	.write_bytes = tpm_tcg_write_bytes,
265 };
266 
267 static int tpm_tis_init(struct device *dev, struct tpm_info *tpm_info)
268 {
269 	struct tpm_tis_tcg_phy *phy;
270 	int irq = -1;
271 	int rc;
272 
273 	dmi_check_system(tpm_tis_dmi_table);
274 
275 	rc = check_acpi_tpm2(dev);
276 	if (rc)
277 		return rc;
278 
279 	phy = devm_kzalloc(dev, sizeof(struct tpm_tis_tcg_phy), GFP_KERNEL);
280 	if (phy == NULL)
281 		return -ENOMEM;
282 
283 	phy->iobase = devm_ioremap_resource(dev, &tpm_info->res);
284 	if (IS_ERR(phy->iobase))
285 		return PTR_ERR(phy->iobase);
286 
287 	if (interrupts)
288 		irq = tpm_info->irq;
289 
290 	if (itpm || is_itpm(ACPI_COMPANION(dev)))
291 		set_bit(TPM_TIS_ITPM_WORKAROUND, &phy->priv.flags);
292 
293 	return tpm_tis_core_init(dev, &phy->priv, irq, &tpm_tcg,
294 				 ACPI_HANDLE(dev));
295 }
296 
297 static SIMPLE_DEV_PM_OPS(tpm_tis_pm, tpm_pm_suspend, tpm_tis_resume);
298 
299 static int tpm_tis_pnp_init(struct pnp_dev *pnp_dev,
300 			    const struct pnp_device_id *pnp_id)
301 {
302 	struct tpm_info tpm_info = {};
303 	struct resource *res;
304 
305 	res = pnp_get_resource(pnp_dev, IORESOURCE_MEM, 0);
306 	if (!res)
307 		return -ENODEV;
308 	tpm_info.res = *res;
309 
310 	if (pnp_irq_valid(pnp_dev, 0))
311 		tpm_info.irq = pnp_irq(pnp_dev, 0);
312 	else
313 		tpm_info.irq = -1;
314 
315 	return tpm_tis_init(&pnp_dev->dev, &tpm_info);
316 }
317 
318 /*
319  * There is a known bug caused by 93e1b7d42e1e ("[PATCH] tpm: add HID module
320  * parameter"). This commit added IFX0102 device ID, which is also used by
321  * tpm_infineon but ignored to add quirks to probe which driver ought to be
322  * used.
323  */
324 
325 static struct pnp_device_id tpm_pnp_tbl[] = {
326 	{"PNP0C31", 0},		/* TPM */
327 	{"ATM1200", 0},		/* Atmel */
328 	{"IFX0102", 0},		/* Infineon */
329 	{"BCM0101", 0},		/* Broadcom */
330 	{"BCM0102", 0},		/* Broadcom */
331 	{"NSC1200", 0},		/* National */
332 	{"ICO0102", 0},		/* Intel */
333 	/* Add new here */
334 	{"", 0},		/* User Specified */
335 	{"", 0}			/* Terminator */
336 };
337 MODULE_DEVICE_TABLE(pnp, tpm_pnp_tbl);
338 
339 static void tpm_tis_pnp_remove(struct pnp_dev *dev)
340 {
341 	struct tpm_chip *chip = pnp_get_drvdata(dev);
342 
343 	tpm_chip_unregister(chip);
344 	tpm_tis_remove(chip);
345 }
346 
347 static struct pnp_driver tis_pnp_driver = {
348 	.name = "tpm_tis",
349 	.id_table = tpm_pnp_tbl,
350 	.probe = tpm_tis_pnp_init,
351 	.remove = tpm_tis_pnp_remove,
352 	.driver	= {
353 		.pm = &tpm_tis_pm,
354 	},
355 };
356 
357 #define TIS_HID_USR_IDX (ARRAY_SIZE(tpm_pnp_tbl) - 2)
358 module_param_string(hid, tpm_pnp_tbl[TIS_HID_USR_IDX].id,
359 		    sizeof(tpm_pnp_tbl[TIS_HID_USR_IDX].id), 0444);
360 MODULE_PARM_DESC(hid, "Set additional specific HID for this driver to probe");
361 
362 static struct platform_device *force_pdev;
363 
364 static int tpm_tis_plat_probe(struct platform_device *pdev)
365 {
366 	struct tpm_info tpm_info = {};
367 	struct resource *res;
368 
369 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
370 	if (res == NULL) {
371 		dev_err(&pdev->dev, "no memory resource defined\n");
372 		return -ENODEV;
373 	}
374 	tpm_info.res = *res;
375 
376 	tpm_info.irq = platform_get_irq_optional(pdev, 0);
377 	if (tpm_info.irq <= 0) {
378 		if (pdev != force_pdev)
379 			tpm_info.irq = -1;
380 		else
381 			/* When forcing auto probe the IRQ */
382 			tpm_info.irq = 0;
383 	}
384 
385 	return tpm_tis_init(&pdev->dev, &tpm_info);
386 }
387 
388 static void tpm_tis_plat_remove(struct platform_device *pdev)
389 {
390 	struct tpm_chip *chip = dev_get_drvdata(&pdev->dev);
391 
392 	tpm_chip_unregister(chip);
393 	tpm_tis_remove(chip);
394 }
395 
396 #ifdef CONFIG_OF
397 static const struct of_device_id tis_of_platform_match[] = {
398 	{.compatible = "tcg,tpm-tis-mmio"},
399 	{},
400 };
401 MODULE_DEVICE_TABLE(of, tis_of_platform_match);
402 #endif
403 
404 static struct platform_driver tis_drv = {
405 	.probe = tpm_tis_plat_probe,
406 	.remove_new = tpm_tis_plat_remove,
407 	.driver = {
408 		.name		= "tpm_tis",
409 		.pm		= &tpm_tis_pm,
410 		.of_match_table = of_match_ptr(tis_of_platform_match),
411 		.acpi_match_table = ACPI_PTR(tpm_acpi_tbl),
412 	},
413 };
414 
415 static int tpm_tis_force_device(void)
416 {
417 	struct platform_device *pdev;
418 	static const struct resource x86_resources[] = {
419 		DEFINE_RES_MEM(0xFED40000, TIS_MEM_LEN)
420 	};
421 
422 	if (!force)
423 		return 0;
424 
425 	/* The driver core will match the name tpm_tis of the device to
426 	 * the tpm_tis platform driver and complete the setup via
427 	 * tpm_tis_plat_probe
428 	 */
429 	pdev = platform_device_register_simple("tpm_tis", -1, x86_resources,
430 					       ARRAY_SIZE(x86_resources));
431 	if (IS_ERR(pdev))
432 		return PTR_ERR(pdev);
433 	force_pdev = pdev;
434 
435 	return 0;
436 }
437 
438 static int __init init_tis(void)
439 {
440 	int rc;
441 
442 	rc = tpm_tis_force_device();
443 	if (rc)
444 		goto err_force;
445 
446 	rc = platform_driver_register(&tis_drv);
447 	if (rc)
448 		goto err_platform;
449 
450 
451 	if (IS_ENABLED(CONFIG_PNP)) {
452 		rc = pnp_register_driver(&tis_pnp_driver);
453 		if (rc)
454 			goto err_pnp;
455 	}
456 
457 	return 0;
458 
459 err_pnp:
460 	platform_driver_unregister(&tis_drv);
461 err_platform:
462 	if (force_pdev)
463 		platform_device_unregister(force_pdev);
464 err_force:
465 	return rc;
466 }
467 
468 static void __exit cleanup_tis(void)
469 {
470 	pnp_unregister_driver(&tis_pnp_driver);
471 	platform_driver_unregister(&tis_drv);
472 
473 	if (force_pdev)
474 		platform_device_unregister(force_pdev);
475 }
476 
477 module_init(init_tis);
478 module_exit(cleanup_tis);
479 MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");
480 MODULE_DESCRIPTION("TPM Driver");
481 MODULE_VERSION("2.0");
482 MODULE_LICENSE("GPL");
483