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 enum crb_ca_request { 38 CRB_CA_REQ_GO_IDLE = BIT(0), 39 CRB_CA_REQ_CMD_READY = BIT(1), 40 }; 41 42 enum crb_ca_status { 43 CRB_CA_STS_ERROR = BIT(0), 44 CRB_CA_STS_TPM_IDLE = BIT(1), 45 }; 46 47 enum crb_start { 48 CRB_START_INVOKE = BIT(0), 49 }; 50 51 enum crb_cancel { 52 CRB_CANCEL_INVOKE = BIT(0), 53 }; 54 55 struct crb_control_area { 56 u32 req; 57 u32 sts; 58 u32 cancel; 59 u32 start; 60 u32 int_enable; 61 u32 int_sts; 62 u32 cmd_size; 63 u32 cmd_pa_low; 64 u32 cmd_pa_high; 65 u32 rsp_size; 66 u64 rsp_pa; 67 } __packed; 68 69 enum crb_status { 70 CRB_STS_COMPLETE = BIT(0), 71 }; 72 73 enum crb_flags { 74 CRB_FL_ACPI_START = BIT(0), 75 CRB_FL_CRB_START = BIT(1), 76 }; 77 78 struct crb_priv { 79 unsigned int flags; 80 void __iomem *iobase; 81 struct crb_control_area __iomem *cca; 82 u8 __iomem *cmd; 83 u8 __iomem *rsp; 84 }; 85 86 static SIMPLE_DEV_PM_OPS(crb_pm, tpm_pm_suspend, tpm_pm_resume); 87 88 static u8 crb_status(struct tpm_chip *chip) 89 { 90 struct crb_priv *priv = dev_get_drvdata(&chip->dev); 91 u8 sts = 0; 92 93 if ((ioread32(&priv->cca->start) & CRB_START_INVOKE) != 94 CRB_START_INVOKE) 95 sts |= CRB_STS_COMPLETE; 96 97 return sts; 98 } 99 100 static int crb_recv(struct tpm_chip *chip, u8 *buf, size_t count) 101 { 102 struct crb_priv *priv = dev_get_drvdata(&chip->dev); 103 unsigned int expected; 104 105 /* sanity check */ 106 if (count < 6) 107 return -EIO; 108 109 if (ioread32(&priv->cca->sts) & CRB_CA_STS_ERROR) 110 return -EIO; 111 112 memcpy_fromio(buf, priv->rsp, 6); 113 expected = be32_to_cpup((__be32 *) &buf[2]); 114 115 if (expected > count) 116 return -EIO; 117 118 memcpy_fromio(&buf[6], &priv->rsp[6], expected - 6); 119 120 return expected; 121 } 122 123 static int crb_do_acpi_start(struct tpm_chip *chip) 124 { 125 union acpi_object *obj; 126 int rc; 127 128 obj = acpi_evaluate_dsm(chip->acpi_dev_handle, 129 CRB_ACPI_START_UUID, 130 CRB_ACPI_START_REVISION_ID, 131 CRB_ACPI_START_INDEX, 132 NULL); 133 if (!obj) 134 return -ENXIO; 135 rc = obj->integer.value == 0 ? 0 : -ENXIO; 136 ACPI_FREE(obj); 137 return rc; 138 } 139 140 static int crb_send(struct tpm_chip *chip, u8 *buf, size_t len) 141 { 142 struct crb_priv *priv = dev_get_drvdata(&chip->dev); 143 int rc = 0; 144 145 if (len > ioread32(&priv->cca->cmd_size)) { 146 dev_err(&chip->dev, 147 "invalid command count value %x %zx\n", 148 (unsigned int) len, 149 (size_t) ioread32(&priv->cca->cmd_size)); 150 return -E2BIG; 151 } 152 153 memcpy_toio(priv->cmd, buf, len); 154 155 /* Make sure that cmd is populated before issuing start. */ 156 wmb(); 157 158 if (priv->flags & CRB_FL_CRB_START) 159 iowrite32(cpu_to_le32(CRB_START_INVOKE), &priv->cca->start); 160 161 if (priv->flags & CRB_FL_ACPI_START) 162 rc = crb_do_acpi_start(chip); 163 164 return rc; 165 } 166 167 static void crb_cancel(struct tpm_chip *chip) 168 { 169 struct crb_priv *priv = dev_get_drvdata(&chip->dev); 170 171 iowrite32(cpu_to_le32(CRB_CANCEL_INVOKE), &priv->cca->cancel); 172 173 /* Make sure that cmd is populated before issuing cancel. */ 174 wmb(); 175 176 if ((priv->flags & CRB_FL_ACPI_START) && crb_do_acpi_start(chip)) 177 dev_err(&chip->dev, "ACPI Start failed\n"); 178 179 iowrite32(0, &priv->cca->cancel); 180 } 181 182 static bool crb_req_canceled(struct tpm_chip *chip, u8 status) 183 { 184 struct crb_priv *priv = dev_get_drvdata(&chip->dev); 185 u32 cancel = ioread32(&priv->cca->cancel); 186 187 return (cancel & CRB_CANCEL_INVOKE) == CRB_CANCEL_INVOKE; 188 } 189 190 static const struct tpm_class_ops tpm_crb = { 191 .flags = TPM_OPS_AUTO_STARTUP, 192 .status = crb_status, 193 .recv = crb_recv, 194 .send = crb_send, 195 .cancel = crb_cancel, 196 .req_canceled = crb_req_canceled, 197 .req_complete_mask = CRB_STS_COMPLETE, 198 .req_complete_val = CRB_STS_COMPLETE, 199 }; 200 201 static int crb_init(struct acpi_device *device, struct crb_priv *priv) 202 { 203 struct tpm_chip *chip; 204 205 chip = tpmm_chip_alloc(&device->dev, &tpm_crb); 206 if (IS_ERR(chip)) 207 return PTR_ERR(chip); 208 209 dev_set_drvdata(&chip->dev, priv); 210 chip->acpi_dev_handle = device->handle; 211 chip->flags = TPM_CHIP_FLAG_TPM2; 212 213 return tpm_chip_register(chip); 214 } 215 216 static int crb_check_resource(struct acpi_resource *ares, void *data) 217 { 218 struct resource *io_res = data; 219 struct resource res; 220 221 if (acpi_dev_resource_memory(ares, &res)) { 222 *io_res = res; 223 io_res->name = NULL; 224 } 225 226 return 1; 227 } 228 229 static void __iomem *crb_map_res(struct device *dev, struct crb_priv *priv, 230 struct resource *io_res, u64 start, u32 size) 231 { 232 struct resource new_res = { 233 .start = start, 234 .end = start + size - 1, 235 .flags = IORESOURCE_MEM, 236 }; 237 238 /* Detect a 64 bit address on a 32 bit system */ 239 if (start != new_res.start) 240 return (void __iomem *) ERR_PTR(-EINVAL); 241 242 if (!resource_contains(io_res, &new_res)) 243 return devm_ioremap_resource(dev, &new_res); 244 245 return priv->iobase + (new_res.start - io_res->start); 246 } 247 248 static int crb_map_io(struct acpi_device *device, struct crb_priv *priv, 249 struct acpi_table_tpm2 *buf) 250 { 251 struct list_head resources; 252 struct resource io_res; 253 struct device *dev = &device->dev; 254 u64 cmd_pa; 255 u32 cmd_size; 256 u64 rsp_pa; 257 u32 rsp_size; 258 int ret; 259 260 INIT_LIST_HEAD(&resources); 261 ret = acpi_dev_get_resources(device, &resources, crb_check_resource, 262 &io_res); 263 if (ret < 0) 264 return ret; 265 acpi_dev_free_resource_list(&resources); 266 267 if (resource_type(&io_res) != IORESOURCE_MEM) { 268 dev_err(dev, 269 FW_BUG "TPM2 ACPI table does not define a memory resource\n"); 270 return -EINVAL; 271 } 272 273 priv->iobase = devm_ioremap_resource(dev, &io_res); 274 if (IS_ERR(priv->iobase)) 275 return PTR_ERR(priv->iobase); 276 277 priv->cca = crb_map_res(dev, priv, &io_res, buf->control_address, 278 sizeof(struct crb_control_area)); 279 if (IS_ERR(priv->cca)) 280 return PTR_ERR(priv->cca); 281 282 cmd_pa = ((u64) ioread32(&priv->cca->cmd_pa_high) << 32) | 283 (u64) ioread32(&priv->cca->cmd_pa_low); 284 cmd_size = ioread32(&priv->cca->cmd_size); 285 priv->cmd = crb_map_res(dev, priv, &io_res, cmd_pa, cmd_size); 286 if (IS_ERR(priv->cmd)) 287 return PTR_ERR(priv->cmd); 288 289 memcpy_fromio(&rsp_pa, &priv->cca->rsp_pa, 8); 290 rsp_pa = le64_to_cpu(rsp_pa); 291 rsp_size = ioread32(&priv->cca->rsp_size); 292 293 if (cmd_pa != rsp_pa) { 294 priv->rsp = crb_map_res(dev, priv, &io_res, rsp_pa, rsp_size); 295 return PTR_ERR_OR_ZERO(priv->rsp); 296 } 297 298 /* According to the PTP specification, overlapping command and response 299 * buffer sizes must be identical. 300 */ 301 if (cmd_size != rsp_size) { 302 dev_err(dev, FW_BUG "overlapping command and response buffer sizes are not identical"); 303 return -EINVAL; 304 } 305 306 priv->rsp = priv->cmd; 307 return 0; 308 } 309 310 static int crb_acpi_add(struct acpi_device *device) 311 { 312 struct acpi_table_tpm2 *buf; 313 struct crb_priv *priv; 314 struct device *dev = &device->dev; 315 acpi_status status; 316 u32 sm; 317 int rc; 318 319 status = acpi_get_table(ACPI_SIG_TPM2, 1, 320 (struct acpi_table_header **) &buf); 321 if (ACPI_FAILURE(status) || buf->header.length < sizeof(*buf)) { 322 dev_err(dev, FW_BUG "failed to get TPM2 ACPI table\n"); 323 return -EINVAL; 324 } 325 326 /* Should the FIFO driver handle this? */ 327 sm = buf->start_method; 328 if (sm == ACPI_TPM2_MEMORY_MAPPED) 329 return -ENODEV; 330 331 priv = devm_kzalloc(dev, sizeof(struct crb_priv), GFP_KERNEL); 332 if (!priv) 333 return -ENOMEM; 334 335 /* The reason for the extra quirk is that the PTT in 4th Gen Core CPUs 336 * report only ACPI start but in practice seems to require both 337 * ACPI start and CRB start. 338 */ 339 if (sm == ACPI_TPM2_COMMAND_BUFFER || sm == ACPI_TPM2_MEMORY_MAPPED || 340 !strcmp(acpi_device_hid(device), "MSFT0101")) 341 priv->flags |= CRB_FL_CRB_START; 342 343 if (sm == ACPI_TPM2_START_METHOD || 344 sm == ACPI_TPM2_COMMAND_BUFFER_WITH_START_METHOD) 345 priv->flags |= CRB_FL_ACPI_START; 346 347 rc = crb_map_io(device, priv, buf); 348 if (rc) 349 return rc; 350 351 return crb_init(device, priv); 352 } 353 354 static int crb_acpi_remove(struct acpi_device *device) 355 { 356 struct device *dev = &device->dev; 357 struct tpm_chip *chip = dev_get_drvdata(dev); 358 359 tpm_chip_unregister(chip); 360 361 return 0; 362 } 363 364 static struct acpi_device_id crb_device_ids[] = { 365 {"MSFT0101", 0}, 366 {"", 0}, 367 }; 368 MODULE_DEVICE_TABLE(acpi, crb_device_ids); 369 370 static struct acpi_driver crb_acpi_driver = { 371 .name = "tpm_crb", 372 .ids = crb_device_ids, 373 .ops = { 374 .add = crb_acpi_add, 375 .remove = crb_acpi_remove, 376 }, 377 .drv = { 378 .pm = &crb_pm, 379 }, 380 }; 381 382 module_acpi_driver(crb_acpi_driver); 383 MODULE_AUTHOR("Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>"); 384 MODULE_DESCRIPTION("TPM2 Driver"); 385 MODULE_VERSION("0.1"); 386 MODULE_LICENSE("GPL"); 387