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.sakki...@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.sakki...@linux.intel.com>
+ *
+ * Maintained by: <tpmdd-de...@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.sakki...@linux.intel.com>");
+MODULE_DESCRIPTION("TPM2 Driver");
+MODULE_VERSION("0.1");
+MODULE_LICENSE("GPL");
--
2.1.0
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
