Messages in this thread Patch in this message | | | From | Jarkko Sakkinen <> | Subject | [PATCH v1 11/12] tpm: Driver for TPM 2.0 CRB Interface | Date | Wed, 24 Sep 2014 12:06:01 +0300 |
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tpm_crb is a driver for TPM 2.0 CRB Interface as defined in
- http://www.trustedcomputinggroup.org/resources/tpm_20_mobile_command_response_buffer_interface_specification - http://www.trustedcomputinggroup.org/resources/server_acpi_specification
Tested with TPM2 PTT included in 4th generation Intel processors.
Notes:
- PTT reports using only ACPI start as start method but seems to require CRB with ACPI start. - cmdReady does not seem to work with PTT. - Does not have yet interrupt based send/receive because I don't have hardware for that.
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> --- drivers/char/tpm/Kconfig | 9 ++ drivers/char/tpm/Makefile | 1 + drivers/char/tpm/tpm_crb.c | 332 +++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 342 insertions(+) create mode 100644 drivers/char/tpm/tpm_crb.c
diff --git a/drivers/char/tpm/Kconfig b/drivers/char/tpm/Kconfig index c54cac3..10c9419 100644 --- a/drivers/char/tpm/Kconfig +++ b/drivers/char/tpm/Kconfig @@ -122,4 +122,13 @@ config TCG_XEN To compile this driver as a module, choose M here; the module will be called xen-tpmfront. +config TCG_CRB + tristate "TPM 2.0 CRB Interface" + depends on X86 && ACPI + ---help--- + If you have a TPM security chip that is compliant with the + TCG CRB 2.0 TPM specification say Yes and it will be accessible + from within Linux. To compile this driver as a module, choose + M here; the module will be called tpm_crb. + endif # TCG_TPM diff --git a/drivers/char/tpm/Makefile b/drivers/char/tpm/Makefile index 5ff5f3d..253e823 100644 --- a/drivers/char/tpm/Makefile +++ b/drivers/char/tpm/Makefile @@ -22,3 +22,4 @@ obj-$(CONFIG_TCG_INFINEON) += tpm_infineon.o obj-$(CONFIG_TCG_IBMVTPM) += tpm_ibmvtpm.o obj-$(CONFIG_TCG_ST33_I2C) += tpm_i2c_stm_st33.o obj-$(CONFIG_TCG_XEN) += xen-tpmfront.o +obj-$(CONFIG_TCG_CRB) += tpm_crb.o diff --git a/drivers/char/tpm/tpm_crb.c b/drivers/char/tpm/tpm_crb.c new file mode 100644 index 0000000..db29bd2 --- /dev/null +++ b/drivers/char/tpm/tpm_crb.c @@ -0,0 +1,332 @@ +/* + * Copyright (C) 2014 Intel Corporation + * + * Authors: + * Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> + * + * Maintained by: <tpmdd-devel@lists.sourceforge.net> + * + * This device driver implements the TPM interface as defined in + * the TCG CRB 2.0 TPM specification. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; version 2 + * of the License. + */ + +#include <linux/acpi.h> +#include <linux/highmem.h> +#include <linux/rculist.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include "tpm.h" + +#define ACPI_SIG_TPM2 "TPM2" + +static const u8 CRB_ACPI_START_UUID[] = { + /* 0000 */ 0xAB, 0x6C, 0xBF, 0x6B, 0x63, 0x54, 0x14, 0x47, + /* 0008 */ 0xB7, 0xCD, 0xF0, 0x20, 0x3C, 0x03, 0x68, 0xD4 +}; + +enum crb_defaults { + CRB_SHORT_TIMEOUT = 1000, + CRB_LONG_TIMEOUT = 2000, + CRB_ACPI_START_REVISION_ID = 1, + CRB_ACPI_START_INDEX = 1, +}; + +enum crb_start_method { + CRB_SM_ACPI_START = 2, + CRB_SM_CRB = 7, + CRB_SM_CRB_WITH_ACPI_START = 8, +}; + +struct acpi_tpm2 { + struct acpi_table_header hdr; + u16 platform_class; + u16 reserved; + u64 control_area_pa; + u32 start_method; +}; + +enum crb_ca_request { + CRB_CA_REQ_GO_IDLE = 0x01, + CRB_CA_REQ_CMD_READY = 0x02, +}; + +enum crb_ca_status { + CRB_CA_STS_ERROR = 0x01, + CRB_CA_STS_TPM_IDLE = 0x02, +}; + +struct crb_control_area { + u32 req; + u32 sts; + u32 cancel; + u32 start; + u32 int_enable; + u32 int_sts; + u32 cmd_size; + u64 cmd_pa; + u32 rsp_size; + u64 rsp_pa; +} __packed; + +enum crb_status { + CRB_STS_COMPLETE = 0x01, +}; + +struct crb_priv { + struct { + unsigned int acpi_start : 1; + unsigned int crb_start : 1; + unsigned int reserved : 30; + } opt; + + struct crb_control_area *cca; + unsigned long cca_pa; + acpi_handle dev_handle; +}; + +#ifdef CONFIG_PM_SLEEP +int crb_suspend(struct device *dev) +{ + return 0; +} + +static int crb_resume(struct device *dev) +{ + struct tpm_chip *chip = dev_get_drvdata(dev); + + (void) tpm_do_selftest(chip); + + return 0; +} +#endif + +static SIMPLE_DEV_PM_OPS(crb_pm, crb_suspend, crb_resume); + +static u8 crb_status(struct tpm_chip *chip) +{ + struct crb_priv *priv = chip->vendor.priv; + u8 sts = 0; + + if ((priv->cca->start & 1) != 1) + sts |= CRB_STS_COMPLETE; + + return sts; +} + +static int crb_recv(struct tpm_chip *chip, u8 *buf, size_t count) +{ + struct crb_priv *priv = chip->vendor.priv; + struct crb_control_area *cca; + unsigned int expected; + unsigned long offset; + u8 *resp; + + cca = priv->cca; + if (cca->sts & CRB_CA_STS_ERROR) + return -EIO; + + offset = cca->rsp_pa - priv->cca_pa; + resp = (u8 *) ((unsigned long) cca + offset); + memcpy(buf, resp, 6); + expected = be32_to_cpu(*(__be32 *) (buf + 2)); + + if (expected > count) + return -EIO; + + memcpy(buf + 6, resp + 6, expected - 6); + + return expected; +} + +static int crb_do_acpi_start(struct tpm_chip *chip) +{ + struct crb_priv *priv = chip->vendor.priv; + union acpi_object *obj; + int rc; + + obj = acpi_evaluate_dsm(priv->dev_handle, + CRB_ACPI_START_UUID, + CRB_ACPI_START_REVISION_ID, + CRB_ACPI_START_INDEX, + NULL); + if (!obj) + return -ENXIO; + rc = obj->integer.value == 0 ? 0 : -ENXIO; + ACPI_FREE(obj); + return rc; +} + +static int crb_send(struct tpm_chip *chip, u8 *buf, size_t len) +{ + struct crb_priv *priv = chip->vendor.priv; + struct crb_control_area *cca; + u8 *cmd; + int rc = 0; + + cca = priv->cca; + + if (len > cca->cmd_size) { + dev_err(chip->dev, + "invalid command count value %x %zx\n", + (unsigned int) len, + (size_t) cca->cmd_size); + return -E2BIG; + } + + cmd = (u8 *) ((unsigned long) cca + cca->cmd_pa - priv->cca_pa); + memcpy(cmd, buf, len); + wmb(); + + cca->start = 1; + rc = crb_do_acpi_start(chip); + return rc; +} + +static void crb_cancel(struct tpm_chip *chip) +{ + struct crb_priv *priv = chip->vendor.priv; + struct crb_control_area *cca; + + cca = priv->cca; + cca->cancel = 1; + wmb(); + + if (crb_do_acpi_start(chip)) + dev_err(chip->dev, "ACPI Start failed\n"); + + cca->cancel = 0; +} + +static bool crb_req_canceled(struct tpm_chip *chip, u8 status) +{ + struct crb_priv *priv = chip->vendor.priv; + + return priv->cca->cancel; +} + +static const struct tpm_class_ops tpm_crb = { + .status = crb_status, + .recv = crb_recv, + .send = crb_send, + .cancel = crb_cancel, + .req_canceled = crb_req_canceled, + .req_complete_mask = CRB_STS_COMPLETE, + .req_complete_val = CRB_STS_COMPLETE, +}; + +static void crb_release(void *data) +{ + struct tpm_chip *chip = (struct tpm_chip *) data; + tpm_remove_hardware(chip->dev); +} + +static int crb_acpi_add(struct acpi_device *device) +{ + struct tpm_chip *chip; + struct acpi_tpm2 *buf; + struct crb_priv *priv; + struct device *dev = &device->dev; + acpi_status status; + u32 sm; + int rc; + + chip = tpm_chip_alloc(dev, &tpm_crb); + if (!chip) + return -ENODEV; + + chip->tpm2 = true; + + rc = tpm_chip_register(chip); + if (rc) { + put_device(chip->dev); + kfree(chip); + return -ENODEV; + } + + status = acpi_get_table(ACPI_SIG_TPM2, 1, + (struct acpi_table_header **) &buf); + if (ACPI_FAILURE(status)) { + dev_err(dev, "could not get TPM2 ACPI table\n"); + rc = -ENODEV; + goto out_err; + } + + priv = (struct crb_priv *) devm_kzalloc(dev, sizeof(struct crb_priv), + GFP_KERNEL); + if (!priv) { + rc = -ENODEV; + goto out_err; + } + + sm = buf->start_method; + + if (sm == CRB_SM_CRB || sm == CRB_SM_CRB_WITH_ACPI_START) + priv->opt.crb_start = 1; + + if (sm == CRB_SM_ACPI_START || sm == CRB_SM_CRB_WITH_ACPI_START) + priv->opt.acpi_start = 1; + + priv->dev_handle = device->handle; + priv->cca_pa = buf->control_area_pa; + priv->cca = (struct crb_control_area *) + devm_ioremap_nocache(dev, buf->control_area_pa, 0x1000); + if (!priv->cca) { + rc = -ENODEV; + goto out_err; + } + + chip->vendor.priv = priv; + + /* Default timeouts and durations */ + chip->vendor.timeout_a = msecs_to_jiffies(CRB_SHORT_TIMEOUT); + chip->vendor.timeout_b = msecs_to_jiffies(CRB_LONG_TIMEOUT); + chip->vendor.timeout_c = msecs_to_jiffies(CRB_SHORT_TIMEOUT); + chip->vendor.timeout_d = msecs_to_jiffies(CRB_SHORT_TIMEOUT); + + chip->vendor.duration[TPM_SHORT] = usecs_to_jiffies(TPM2_DURATION_SHORT); + chip->vendor.duration[TPM_MEDIUM] = usecs_to_jiffies(TPM2_DURATION_MEDIUM); + chip->vendor.duration[TPM_LONG] = usecs_to_jiffies(TPM2_DURATION_LONG); + + rc = tpm_do_selftest(chip); + if (rc) { + rc = -ENODEV; + goto out_err; + } + + rc = devm_add_action(dev, crb_release, chip); + if (rc) + goto out_err; + + return 0; +out_err: + tpm_remove_hardware(chip->dev); + return rc; +} + +static struct acpi_device_id crb_device_ids[] = { + {"MSFT0101", 0}, + {"", 0}, +}; +MODULE_DEVICE_TABLE(acpi, crb_device_ids); + +static struct acpi_driver crb_acpi_driver = { + .name = "tpm_crb", + .ids = crb_device_ids, + .ops = { + .add = crb_acpi_add, + }, + .drv = { + .pm = &crb_pm, + }, +}; + +module_acpi_driver(crb_acpi_driver); +MODULE_AUTHOR("Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>"); +MODULE_DESCRIPTION("TPM2 Driver"); +MODULE_VERSION("0.1"); +MODULE_LICENSE("GPL"); -- 2.1.0
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