drivers/char/tpm/tpm_tis.c

   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 "tpm.h"
  30 #include "tpm_tis_core.h"
  31
  32 struct tpm_info {
  33         struct resource res;
  34         /* irq > 0 means: use irq $irq;
  35          * irq = 0 means: autoprobe for an irq;
  36          * irq = -1 means: no irq support
  37          */
  38         int irq;
  39 };
  40
  41 struct tpm_tis_tcg_phy {
  42         struct tpm_tis_data priv;
  43         void __iomem *iobase;
  44 };
  45
  46 static inline struct tpm_tis_tcg_phy *to_tpm_tis_tcg_phy(struct tpm_tis_data *data)
  47 {
  48         return container_of(data, struct tpm_tis_tcg_phy, priv);
  49 }
  50
  51 #ifdef CONFIG_PREEMPT_RT
  52 /*
  53  * Flush previous write operations with a dummy read operation to the
  54  * TPM MMIO base address.
  55  */
  56 static inline void tpm_tis_flush(void __iomem *iobase)
  57 {
  58         ioread8(iobase + TPM_ACCESS(0));
  59 }
  60 #else
  61 #define tpm_tis_flush(iobase) do { } while (0)
  62 #endif
  63
  64 /*
  65  * Write a byte word to the TPM MMIO address, and flush the write queue.
  66  * The flush ensures that the data is sent immediately over the bus and not
  67  * aggregated with further requests and transferred later in a batch. The large
  68  * write requests can lead to unwanted latency spikes by blocking the CPU until
  69  * the complete batch has been transferred.
  70  */
  71 static inline void tpm_tis_iowrite8(u8 b, void __iomem *iobase, u32 addr)
  72 {
  73         iowrite8(b, iobase + addr);
  74         tpm_tis_flush(iobase);
  75 }
  76
  77 /*
  78  * Write a 32-bit word to the TPM MMIO address, and flush the write queue.
  79  * The flush ensures that the data is sent immediately over the bus and not
  80  * aggregated with further requests and transferred later in a batch. The large
  81  * write requests can lead to unwanted latency spikes by blocking the CPU until
  82  * the complete batch has been transferred.
  83  */
  84 static inline void tpm_tis_iowrite32(u32 b, void __iomem *iobase, u32 addr)
  85 {
  86         iowrite32(b, iobase + addr);
  87         tpm_tis_flush(iobase);
  88 }
  89
  90 static bool interrupts;
  91 module_param(interrupts, bool, 0444);
  92 MODULE_PARM_DESC(interrupts, "Enable interrupts");
  93
  94 static bool itpm;
  95 module_param(itpm, bool, 0444);
  96 MODULE_PARM_DESC(itpm, "Force iTPM workarounds (found on some Lenovo laptops)");
  97
  98 static bool force;
  99 #ifdef CONFIG_X86
 100 module_param(force, bool, 0444);
 101 MODULE_PARM_DESC(force, "Force device probe rather than using ACPI entry");
 102 #endif
 103
 104 #if defined(CONFIG_PNP) && defined(CONFIG_ACPI)
 105 static int has_hid(struct acpi_device *dev, const char *hid)
 106 {
 107         struct acpi_hardware_id *id;
 108
 109         list_for_each_entry(id, &dev->pnp.ids, list)
 110                 if (!strcmp(hid, id->id))
 111                         return 1;
 112
 113         return 0;
 114 }
 115
 116 static inline int is_itpm(struct acpi_device *dev)
 117 {
 118         if (!dev)
 119                 return 0;
 120         return has_hid(dev, "INTC0102");
 121 }
 122 #else
 123 static inline int is_itpm(struct acpi_device *dev)
 124 {
 125         return 0;
 126 }
 127 #endif
 128
 129 #if defined(CONFIG_ACPI)
 130 #define DEVICE_IS_TPM2 1
 131
 132 static const struct acpi_device_id tpm_acpi_tbl[] = {
 133         {"MSFT0101", DEVICE_IS_TPM2},
 134         {},
 135 };
 136 MODULE_DEVICE_TABLE(acpi, tpm_acpi_tbl);
 137
 138 static int check_acpi_tpm2(struct device *dev)
 139 {
 140         const struct acpi_device_id *aid = acpi_match_device(tpm_acpi_tbl, dev);
 141         struct acpi_table_tpm2 *tbl;
 142         acpi_status st;
 143         int ret = 0;
 144
 145         if (!aid || aid->driver_data != DEVICE_IS_TPM2)
 146                 return 0;
 147
 148         /* If the ACPI TPM2 signature is matched then a global ACPI_SIG_TPM2
 149          * table is mandatory
 150          */
 151         st = acpi_get_table(ACPI_SIG_TPM2, 1, (struct acpi_table_header **)&tbl);
 152         if (ACPI_FAILURE(st) || tbl->header.length < sizeof(*tbl)) {
 153                 dev_err(dev, FW_BUG "failed to get TPM2 ACPI table\n");
 154                 return -EINVAL;
 155         }
 156
 157         /* The tpm2_crb driver handles this device */
 158         if (tbl->start_method != ACPI_TPM2_MEMORY_MAPPED)
 159                 ret = -ENODEV;
 160
 161         acpi_put_table((struct acpi_table_header *)tbl);
 162         return ret;
 163 }
 164 #else
 165 static int check_acpi_tpm2(struct device *dev)
 166 {
 167         return 0;
 168 }
 169 #endif
 170
 171 static int tpm_tcg_read_bytes(struct tpm_tis_data *data, u32 addr, u16 len,
 172                               u8 *result, enum tpm_tis_io_mode io_mode)
 173 {
 174         struct tpm_tis_tcg_phy *phy = to_tpm_tis_tcg_phy(data);
 175         __le16 result_le16;
 176         __le32 result_le32;
 177
 178         switch (io_mode) {
 179         case TPM_TIS_PHYS_8:
 180                 while (len--)
 181                         *result++ = ioread8(phy->iobase + addr);
 182                 break;
 183         case TPM_TIS_PHYS_16:
 184                 result_le16 = cpu_to_le16(ioread16(phy->iobase + addr));
 185                 memcpy(result, &result_le16, sizeof(u16));
 186                 break;
 187         case TPM_TIS_PHYS_32:
 188                 result_le32 = cpu_to_le32(ioread32(phy->iobase + addr));
 189                 memcpy(result, &result_le32, sizeof(u32));
 190                 break;
 191         }
 192
 193         return 0;
 194 }
 195
 196 static int tpm_tcg_write_bytes(struct tpm_tis_data *data, u32 addr, u16 len,
 197                                const u8 *value, enum tpm_tis_io_mode io_mode)
 198 {
 199         struct tpm_tis_tcg_phy *phy = to_tpm_tis_tcg_phy(data);
 200
 201         switch (io_mode) {
 202         case TPM_TIS_PHYS_8:
 203                 while (len--)
 204                         tpm_tis_iowrite8(*value++, phy->iobase, addr);
 205                 break;
 206         case TPM_TIS_PHYS_16:
 207                 return -EINVAL;
 208         case TPM_TIS_PHYS_32:
 209                 tpm_tis_iowrite32(le32_to_cpu(*((__le32 *)value)), phy->iobase, addr);
 210                 break;
 211         }
 212
 213         return 0;
 214 }
 215
 216 static const struct tpm_tis_phy_ops tpm_tcg = {
 217         .read_bytes = tpm_tcg_read_bytes,
 218         .write_bytes = tpm_tcg_write_bytes,
 219 };
 220
 221 static int tpm_tis_init(struct device *dev, struct tpm_info *tpm_info)
 222 {
 223         struct tpm_tis_tcg_phy *phy;
 224         int irq = -1;
 225         int rc;
 226
 227         rc = check_acpi_tpm2(dev);
 228         if (rc)
 229                 return rc;
 230
 231         phy = devm_kzalloc(dev, sizeof(struct tpm_tis_tcg_phy), GFP_KERNEL);
 232         if (phy == NULL)
 233                 return -ENOMEM;
 234
 235         phy->iobase = devm_ioremap_resource(dev, &tpm_info->res);
 236         if (IS_ERR(phy->iobase))
 237                 return PTR_ERR(phy->iobase);
 238
 239         if (interrupts)
 240                 irq = tpm_info->irq;
 241
 242         if (itpm || is_itpm(ACPI_COMPANION(dev)))
 243                 set_bit(TPM_TIS_ITPM_WORKAROUND, &phy->priv.flags);
 244
 245         return tpm_tis_core_init(dev, &phy->priv, irq, &tpm_tcg,
 246                                  ACPI_HANDLE(dev));
 247 }
 248
 249 static SIMPLE_DEV_PM_OPS(tpm_tis_pm, tpm_pm_suspend, tpm_tis_resume);
 250
 251 static int tpm_tis_pnp_init(struct pnp_dev *pnp_dev,
 252                             const struct pnp_device_id *pnp_id)
 253 {
 254         struct tpm_info tpm_info = {};
 255         struct resource *res;
 256
 257         res = pnp_get_resource(pnp_dev, IORESOURCE_MEM, 0);
 258         if (!res)
 259                 return -ENODEV;
 260         tpm_info.res = *res;
 261
 262         if (pnp_irq_valid(pnp_dev, 0))
 263                 tpm_info.irq = pnp_irq(pnp_dev, 0);
 264         else
 265                 tpm_info.irq = -1;
 266
 267         return tpm_tis_init(&pnp_dev->dev, &tpm_info);
 268 }
 269
 270 /*
 271  * There is a known bug caused by 93e1b7d42e1e ("[PATCH] tpm: add HID module
 272  * parameter"). This commit added IFX0102 device ID, which is also used by
 273  * tpm_infineon but ignored to add quirks to probe which driver ought to be
 274  * used.
 275  */
 276
 277 static struct pnp_device_id tpm_pnp_tbl[] = {
 278         {"PNP0C31", 0},         /* TPM */
 279         {"ATM1200", 0},         /* Atmel */
 280         {"IFX0102", 0},         /* Infineon */
 281         {"BCM0101", 0},         /* Broadcom */
 282         {"BCM0102", 0},         /* Broadcom */
 283         {"NSC1200", 0},         /* National */
 284         {"ICO0102", 0},         /* Intel */
 285         /* Add new here */
 286         {"", 0},                /* User Specified */
 287         {"", 0}                 /* Terminator */
 288 };
 289 MODULE_DEVICE_TABLE(pnp, tpm_pnp_tbl);
 290
 291 static void tpm_tis_pnp_remove(struct pnp_dev *dev)
 292 {
 293         struct tpm_chip *chip = pnp_get_drvdata(dev);
 294
 295         tpm_chip_unregister(chip);
 296         tpm_tis_remove(chip);
 297 }
 298
 299 static struct pnp_driver tis_pnp_driver = {
 300         .name = "tpm_tis",
 301         .id_table = tpm_pnp_tbl,
 302         .probe = tpm_tis_pnp_init,
 303         .remove = tpm_tis_pnp_remove,
 304         .driver = {
 305                 .pm = &tpm_tis_pm,
 306         },
 307 };
 308
 309 #define TIS_HID_USR_IDX (ARRAY_SIZE(tpm_pnp_tbl) - 2)
 310 module_param_string(hid, tpm_pnp_tbl[TIS_HID_USR_IDX].id,
 311                     sizeof(tpm_pnp_tbl[TIS_HID_USR_IDX].id), 0444);
 312 MODULE_PARM_DESC(hid, "Set additional specific HID for this driver to probe");
 313
 314 static struct platform_device *force_pdev;
 315
 316 static int tpm_tis_plat_probe(struct platform_device *pdev)
 317 {
 318         struct tpm_info tpm_info = {};
 319         struct resource *res;
 320
 321         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 322         if (res == NULL) {
 323                 dev_err(&pdev->dev, "no memory resource defined\n");
 324                 return -ENODEV;
 325         }
 326         tpm_info.res = *res;
 327
 328         tpm_info.irq = platform_get_irq_optional(pdev, 0);
 329         if (tpm_info.irq <= 0) {
 330                 if (pdev != force_pdev)
 331                         tpm_info.irq = -1;
 332                 else
 333                         /* When forcing auto probe the IRQ */
 334                         tpm_info.irq = 0;
 335         }
 336
 337         return tpm_tis_init(&pdev->dev, &tpm_info);
 338 }
 339
 340 static void tpm_tis_plat_remove(struct platform_device *pdev)
 341 {
 342         struct tpm_chip *chip = dev_get_drvdata(&pdev->dev);
 343
 344         tpm_chip_unregister(chip);
 345         tpm_tis_remove(chip);
 346 }
 347
 348 #ifdef CONFIG_OF
 349 static const struct of_device_id tis_of_platform_match[] = {
 350         {.compatible = "atmel,at97sc3204"},
 351         {.compatible = "tcg,tpm-tis-mmio"},
 352         {},
 353 };
 354 MODULE_DEVICE_TABLE(of, tis_of_platform_match);
 355 #endif
 356
 357 static struct platform_driver tis_drv = {
 358         .probe = tpm_tis_plat_probe,
 359         .remove = tpm_tis_plat_remove,
 360         .driver = {
 361                 .name           = "tpm_tis",
 362                 .pm             = &tpm_tis_pm,
 363                 .of_match_table = of_match_ptr(tis_of_platform_match),
 364                 .acpi_match_table = ACPI_PTR(tpm_acpi_tbl),
 365         },
 366 };
 367
 368 static int tpm_tis_force_device(void)
 369 {
 370         struct platform_device *pdev;
 371         static const struct resource x86_resources[] = {
 372                 DEFINE_RES_MEM(0xFED40000, TIS_MEM_LEN)
 373         };
 374
 375         if (!force)
 376                 return 0;
 377
 378         /* The driver core will match the name tpm_tis of the device to
 379          * the tpm_tis platform driver and complete the setup via
 380          * tpm_tis_plat_probe
 381          */
 382         pdev = platform_device_register_simple("tpm_tis", -1, x86_resources,
 383                                                ARRAY_SIZE(x86_resources));
 384         if (IS_ERR(pdev))
 385                 return PTR_ERR(pdev);
 386         force_pdev = pdev;
 387
 388         return 0;
 389 }
 390
 391 static int __init init_tis(void)
 392 {
 393         int rc;
 394
 395         rc = tpm_tis_force_device();
 396         if (rc)
 397                 goto err_force;
 398
 399         rc = platform_driver_register(&tis_drv);
 400         if (rc)
 401                 goto err_platform;
 402
 403
 404         if (IS_ENABLED(CONFIG_PNP)) {
 405                 rc = pnp_register_driver(&tis_pnp_driver);
 406                 if (rc)
 407                         goto err_pnp;
 408         }
 409
 410         return 0;
 411
 412 err_pnp:
 413         platform_driver_unregister(&tis_drv);
 414 err_platform:
 415         if (force_pdev)
 416                 platform_device_unregister(force_pdev);
 417 err_force:
 418         return rc;
 419 }
 420
 421 static void __exit cleanup_tis(void)
 422 {
 423         pnp_unregister_driver(&tis_pnp_driver);
 424         platform_driver_unregister(&tis_drv);
 425
 426         if (force_pdev)
 427                 platform_device_unregister(force_pdev);
 428 }
 429
 430 module_init(init_tis);
 431 module_exit(cleanup_tis);
 432 MODULE_AUTHOR("Leendert van Doorn <leendert@watson.ibm.com>");
 433 MODULE_DESCRIPTION("TPM Driver");
 434 MODULE_VERSION("2.0");
 435 MODULE_LICENSE("GPL");