xref: /openbmc/linux/drivers/char/tpm/tpm_tis.c (revision 081e8df6)
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 		.callback = tpm_tis_disable_irq,
127 		.ident = "ThinkStation P360 Tiny",
128 		.matches = {
129 			DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
130 			DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkStation P360 Tiny"),
131 		},
132 	},
133 	{
134 		.callback = tpm_tis_disable_irq,
135 		.ident = "ThinkPad L490",
136 		.matches = {
137 			DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
138 			DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad L490"),
139 		},
140 	},
141 	{
142 		.callback = tpm_tis_disable_irq,
143 		.ident = "UPX-TGL",
144 		.matches = {
145 			DMI_MATCH(DMI_SYS_VENDOR, "AAEON"),
146 		},
147 	},
148 	{}
149 };
150 
151 #if defined(CONFIG_PNP) && defined(CONFIG_ACPI)
152 static int has_hid(struct acpi_device *dev, const char *hid)
153 {
154 	struct acpi_hardware_id *id;
155 
156 	list_for_each_entry(id, &dev->pnp.ids, list)
157 		if (!strcmp(hid, id->id))
158 			return 1;
159 
160 	return 0;
161 }
162 
163 static inline int is_itpm(struct acpi_device *dev)
164 {
165 	if (!dev)
166 		return 0;
167 	return has_hid(dev, "INTC0102");
168 }
169 #else
170 static inline int is_itpm(struct acpi_device *dev)
171 {
172 	return 0;
173 }
174 #endif
175 
176 #if defined(CONFIG_ACPI)
177 #define DEVICE_IS_TPM2 1
178 
179 static const struct acpi_device_id tpm_acpi_tbl[] = {
180 	{"MSFT0101", DEVICE_IS_TPM2},
181 	{},
182 };
183 MODULE_DEVICE_TABLE(acpi, tpm_acpi_tbl);
184 
185 static int check_acpi_tpm2(struct device *dev)
186 {
187 	const struct acpi_device_id *aid = acpi_match_device(tpm_acpi_tbl, dev);
188 	struct acpi_table_tpm2 *tbl;
189 	acpi_status st;
190 	int ret = 0;
191 
192 	if (!aid || aid->driver_data != DEVICE_IS_TPM2)
193 		return 0;
194 
195 	/* If the ACPI TPM2 signature is matched then a global ACPI_SIG_TPM2
196 	 * table is mandatory
197 	 */
198 	st = acpi_get_table(ACPI_SIG_TPM2, 1, (struct acpi_table_header **)&tbl);
199 	if (ACPI_FAILURE(st) || tbl->header.length < sizeof(*tbl)) {
200 		dev_err(dev, FW_BUG "failed to get TPM2 ACPI table\n");
201 		return -EINVAL;
202 	}
203 
204 	/* The tpm2_crb driver handles this device */
205 	if (tbl->start_method != ACPI_TPM2_MEMORY_MAPPED)
206 		ret = -ENODEV;
207 
208 	acpi_put_table((struct acpi_table_header *)tbl);
209 	return ret;
210 }
211 #else
212 static int check_acpi_tpm2(struct device *dev)
213 {
214 	return 0;
215 }
216 #endif
217 
218 static int tpm_tcg_read_bytes(struct tpm_tis_data *data, u32 addr, u16 len,
219 			      u8 *result, enum tpm_tis_io_mode io_mode)
220 {
221 	struct tpm_tis_tcg_phy *phy = to_tpm_tis_tcg_phy(data);
222 	__le16 result_le16;
223 	__le32 result_le32;
224 
225 	switch (io_mode) {
226 	case TPM_TIS_PHYS_8:
227 		while (len--)
228 			*result++ = ioread8(phy->iobase + addr);
229 		break;
230 	case TPM_TIS_PHYS_16:
231 		result_le16 = cpu_to_le16(ioread16(phy->iobase + addr));
232 		memcpy(result, &result_le16, sizeof(u16));
233 		break;
234 	case TPM_TIS_PHYS_32:
235 		result_le32 = cpu_to_le32(ioread32(phy->iobase + addr));
236 		memcpy(result, &result_le32, sizeof(u32));
237 		break;
238 	}
239 
240 	return 0;
241 }
242 
243 static int tpm_tcg_write_bytes(struct tpm_tis_data *data, u32 addr, u16 len,
244 			       const u8 *value, enum tpm_tis_io_mode io_mode)
245 {
246 	struct tpm_tis_tcg_phy *phy = to_tpm_tis_tcg_phy(data);
247 
248 	switch (io_mode) {
249 	case TPM_TIS_PHYS_8:
250 		while (len--)
251 			tpm_tis_iowrite8(*value++, phy->iobase, addr);
252 		break;
253 	case TPM_TIS_PHYS_16:
254 		return -EINVAL;
255 	case TPM_TIS_PHYS_32:
256 		tpm_tis_iowrite32(le32_to_cpu(*((__le32 *)value)), phy->iobase, addr);
257 		break;
258 	}
259 
260 	return 0;
261 }
262 
263 static const struct tpm_tis_phy_ops tpm_tcg = {
264 	.read_bytes = tpm_tcg_read_bytes,
265 	.write_bytes = tpm_tcg_write_bytes,
266 };
267 
268 static int tpm_tis_init(struct device *dev, struct tpm_info *tpm_info)
269 {
270 	struct tpm_tis_tcg_phy *phy;
271 	int irq = -1;
272 	int rc;
273 
274 	dmi_check_system(tpm_tis_dmi_table);
275 
276 	rc = check_acpi_tpm2(dev);
277 	if (rc)
278 		return rc;
279 
280 	phy = devm_kzalloc(dev, sizeof(struct tpm_tis_tcg_phy), GFP_KERNEL);
281 	if (phy == NULL)
282 		return -ENOMEM;
283 
284 	phy->iobase = devm_ioremap_resource(dev, &tpm_info->res);
285 	if (IS_ERR(phy->iobase))
286 		return PTR_ERR(phy->iobase);
287 
288 	if (interrupts)
289 		irq = tpm_info->irq;
290 
291 	if (itpm || is_itpm(ACPI_COMPANION(dev)))
292 		set_bit(TPM_TIS_ITPM_WORKAROUND, &phy->priv.flags);
293 
294 	return tpm_tis_core_init(dev, &phy->priv, irq, &tpm_tcg,
295 				 ACPI_HANDLE(dev));
296 }
297 
298 static SIMPLE_DEV_PM_OPS(tpm_tis_pm, tpm_pm_suspend, tpm_tis_resume);
299 
300 static int tpm_tis_pnp_init(struct pnp_dev *pnp_dev,
301 			    const struct pnp_device_id *pnp_id)
302 {
303 	struct tpm_info tpm_info = {};
304 	struct resource *res;
305 
306 	res = pnp_get_resource(pnp_dev, IORESOURCE_MEM, 0);
307 	if (!res)
308 		return -ENODEV;
309 	tpm_info.res = *res;
310 
311 	if (pnp_irq_valid(pnp_dev, 0))
312 		tpm_info.irq = pnp_irq(pnp_dev, 0);
313 	else
314 		tpm_info.irq = -1;
315 
316 	return tpm_tis_init(&pnp_dev->dev, &tpm_info);
317 }
318 
319 /*
320  * There is a known bug caused by 93e1b7d42e1e ("[PATCH] tpm: add HID module
321  * parameter"). This commit added IFX0102 device ID, which is also used by
322  * tpm_infineon but ignored to add quirks to probe which driver ought to be
323  * used.
324  */
325 
326 static struct pnp_device_id tpm_pnp_tbl[] = {
327 	{"PNP0C31", 0},		/* TPM */
328 	{"ATM1200", 0},		/* Atmel */
329 	{"IFX0102", 0},		/* Infineon */
330 	{"BCM0101", 0},		/* Broadcom */
331 	{"BCM0102", 0},		/* Broadcom */
332 	{"NSC1200", 0},		/* National */
333 	{"ICO0102", 0},		/* Intel */
334 	/* Add new here */
335 	{"", 0},		/* User Specified */
336 	{"", 0}			/* Terminator */
337 };
338 MODULE_DEVICE_TABLE(pnp, tpm_pnp_tbl);
339 
340 static void tpm_tis_pnp_remove(struct pnp_dev *dev)
341 {
342 	struct tpm_chip *chip = pnp_get_drvdata(dev);
343 
344 	tpm_chip_unregister(chip);
345 	tpm_tis_remove(chip);
346 }
347 
348 static struct pnp_driver tis_pnp_driver = {
349 	.name = "tpm_tis",
350 	.id_table = tpm_pnp_tbl,
351 	.probe = tpm_tis_pnp_init,
352 	.remove = tpm_tis_pnp_remove,
353 	.driver	= {
354 		.pm = &tpm_tis_pm,
355 	},
356 };
357 
358 #define TIS_HID_USR_IDX (ARRAY_SIZE(tpm_pnp_tbl) - 2)
359 module_param_string(hid, tpm_pnp_tbl[TIS_HID_USR_IDX].id,
360 		    sizeof(tpm_pnp_tbl[TIS_HID_USR_IDX].id), 0444);
361 MODULE_PARM_DESC(hid, "Set additional specific HID for this driver to probe");
362 
363 static struct platform_device *force_pdev;
364 
365 static int tpm_tis_plat_probe(struct platform_device *pdev)
366 {
367 	struct tpm_info tpm_info = {};
368 	struct resource *res;
369 
370 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
371 	if (res == NULL) {
372 		dev_err(&pdev->dev, "no memory resource defined\n");
373 		return -ENODEV;
374 	}
375 	tpm_info.res = *res;
376 
377 	tpm_info.irq = platform_get_irq_optional(pdev, 0);
378 	if (tpm_info.irq <= 0) {
379 		if (pdev != force_pdev)
380 			tpm_info.irq = -1;
381 		else
382 			/* When forcing auto probe the IRQ */
383 			tpm_info.irq = 0;
384 	}
385 
386 	return tpm_tis_init(&pdev->dev, &tpm_info);
387 }
388 
389 static void tpm_tis_plat_remove(struct platform_device *pdev)
390 {
391 	struct tpm_chip *chip = dev_get_drvdata(&pdev->dev);
392 
393 	tpm_chip_unregister(chip);
394 	tpm_tis_remove(chip);
395 }
396 
397 #ifdef CONFIG_OF
398 static const struct of_device_id tis_of_platform_match[] = {
399 	{.compatible = "tcg,tpm-tis-mmio"},
400 	{},
401 };
402 MODULE_DEVICE_TABLE(of, tis_of_platform_match);
403 #endif
404 
405 static struct platform_driver tis_drv = {
406 	.probe = tpm_tis_plat_probe,
407 	.remove_new = tpm_tis_plat_remove,
408 	.driver = {
409 		.name		= "tpm_tis",
410 		.pm		= &tpm_tis_pm,
411 		.of_match_table = of_match_ptr(tis_of_platform_match),
412 		.acpi_match_table = ACPI_PTR(tpm_acpi_tbl),
413 	},
414 };
415 
416 static int tpm_tis_force_device(void)
417 {
418 	struct platform_device *pdev;
419 	static const struct resource x86_resources[] = {
420 		DEFINE_RES_MEM(0xFED40000, TIS_MEM_LEN)
421 	};
422 
423 	if (!force)
424 		return 0;
425 
426 	/* The driver core will match the name tpm_tis of the device to
427 	 * the tpm_tis platform driver and complete the setup via
428 	 * tpm_tis_plat_probe
429 	 */
430 	pdev = platform_device_register_simple("tpm_tis", -1, x86_resources,
431 					       ARRAY_SIZE(x86_resources));
432 	if (IS_ERR(pdev))
433 		return PTR_ERR(pdev);
434 	force_pdev = pdev;
435 
436 	return 0;
437 }
438 
439 static int __init init_tis(void)
440 {
441 	int rc;
442 
443 	rc = tpm_tis_force_device();
444 	if (rc)
445 		goto err_force;
446 
447 	rc = platform_driver_register(&tis_drv);
448 	if (rc)
449 		goto err_platform;
450 
451 
452 	if (IS_ENABLED(CONFIG_PNP)) {
453 		rc = pnp_register_driver(&tis_pnp_driver);
454 		if (rc)
455 			goto err_pnp;
456 	}
457 
458 	return 0;
459 
460 err_pnp:
461 	platform_driver_unregister(&tis_drv);
462 err_platform:
463 	if (force_pdev)
464 		platform_device_unregister(force_pdev);
465 err_force:
466 	return rc;
467 }
468 
469 static void __exit cleanup_tis(void)
470 {
471 	pnp_unregister_driver(&tis_pnp_driver);
472 	platform_driver_unregister(&tis_drv);
473 
474 	if (force_pdev)
475 		platform_device_unregister(force_pdev);
476 }
477 
478 module_init(init_tis);
479 module_exit(cleanup_tis);
480 MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");
481 MODULE_DESCRIPTION("TPM Driver");
482 MODULE_VERSION("2.0");
483 MODULE_LICENSE("GPL");
484