1 files changed, 352 insertions, 0 deletions

diff --git a/drivers/char/tpm/tpm_crb.c b/drivers/char/tpm/tpm_crb.c
new file mode 100644
index 000000000..126732259
--- /dev/null
+++ b/drivers/char/tpm/tpm_crb.c
@@ -0,0 +1,352 @@
+/*
+ * 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_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;
+} __packed;
+
+enum crb_ca_request {
+	CRB_CA_REQ_GO_IDLE	= BIT(0),
+	CRB_CA_REQ_CMD_READY	= BIT(1),
+};
+
+enum crb_ca_status {
+	CRB_CA_STS_ERROR	= BIT(0),
+	CRB_CA_STS_TPM_IDLE	= BIT(1),
+};
+
+enum crb_start {
+	CRB_START_INVOKE	= BIT(0),
+};
+
+enum crb_cancel {
+	CRB_CANCEL_INVOKE	= BIT(0),
+};
+
+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	= BIT(0),
+};
+
+enum crb_flags {
+	CRB_FL_ACPI_START	= BIT(0),
+	CRB_FL_CRB_START	= BIT(1),
+};
+
+struct crb_priv {
+	unsigned int flags;
+	struct crb_control_area __iomem *cca;
+	u8 __iomem *cmd;
+	u8 __iomem *rsp;
+};
+
+static SIMPLE_DEV_PM_OPS(crb_pm, tpm_pm_suspend, tpm_pm_resume);
+
+static u8 crb_status(struct tpm_chip *chip)
+{
+	struct crb_priv *priv = chip->vendor.priv;
+	u8 sts = 0;
+
+	if ((le32_to_cpu(ioread32(&priv->cca->start)) & CRB_START_INVOKE) !=
+	    CRB_START_INVOKE)
+		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;
+	unsigned int expected;
+
+	/* sanity check */
+	if (count < 6)
+		return -EIO;
+
+	if (le32_to_cpu(ioread32(&priv->cca->sts)) & CRB_CA_STS_ERROR)
+		return -EIO;
+
+	memcpy_fromio(buf, priv->rsp, 6);
+	expected = be32_to_cpup((__be32 *) &buf[2]);
+
+	if (expected > count)
+		return -EIO;
+
+	memcpy_fromio(&buf[6], &priv->rsp[6], expected - 6);
+
+	return expected;
+}
+
+static int crb_do_acpi_start(struct tpm_chip *chip)
+{
+	union acpi_object *obj;
+	int rc;
+
+	obj = acpi_evaluate_dsm(chip->acpi_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;
+	int rc = 0;
+
+	if (len > le32_to_cpu(ioread32(&priv->cca->cmd_size))) {
+		dev_err(&chip->dev,
+			"invalid command count value %x %zx\n",
+			(unsigned int) len,
+			(size_t) le32_to_cpu(ioread32(&priv->cca->cmd_size)));
+		return -E2BIG;
+	}
+
+	memcpy_toio(priv->cmd, buf, len);
+
+	/* Make sure that cmd is populated before issuing start. */
+	wmb();
+
+	if (priv->flags & CRB_FL_CRB_START)
+		iowrite32(cpu_to_le32(CRB_START_INVOKE), &priv->cca->start);
+
+	if (priv->flags & CRB_FL_ACPI_START)
+		rc = crb_do_acpi_start(chip);
+
+	return rc;
+}
+
+static void crb_cancel(struct tpm_chip *chip)
+{
+	struct crb_priv *priv = chip->vendor.priv;
+
+	iowrite32(cpu_to_le32(CRB_CANCEL_INVOKE), &priv->cca->cancel);
+
+	/* Make sure that cmd is populated before issuing cancel. */
+	wmb();
+
+	if ((priv->flags & CRB_FL_ACPI_START) && crb_do_acpi_start(chip))
+		dev_err(&chip->dev, "ACPI Start failed\n");
+
+	iowrite32(0, &priv->cca->cancel);
+}
+
+static bool crb_req_canceled(struct tpm_chip *chip, u8 status)
+{
+	struct crb_priv *priv = chip->vendor.priv;
+	u32 cancel = le32_to_cpu(ioread32(&priv->cca->cancel));
+
+	return (cancel & CRB_CANCEL_INVOKE) == CRB_CANCEL_INVOKE;
+}
+
+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 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;
+	u64 pa;
+	int rc;
+
+	chip = tpmm_chip_alloc(dev, &tpm_crb);
+	if (IS_ERR(chip))
+		return PTR_ERR(chip);
+
+	chip->flags = TPM_CHIP_FLAG_TPM2;
+
+	status = acpi_get_table(ACPI_SIG_TPM2, 1,
+				(struct acpi_table_header **) &buf);
+	if (ACPI_FAILURE(status)) {
+		dev_err(dev, "failed to get TPM2 ACPI table\n");
+		return -ENODEV;
+	}
+
+	/* At least some versions of AMI BIOS have a bug that TPM2 table has
+	 * zero address for the control area and therefore we must fail.
+	*/
+	if (!buf->control_area_pa) {
+		dev_err(dev, "TPM2 ACPI table has a zero address for the control area\n");
+		return -EINVAL;
+	}
+
+	if (buf->hdr.length < sizeof(struct acpi_tpm2)) {
+		dev_err(dev, "TPM2 ACPI table has wrong size");
+		return -EINVAL;
+	}
+
+	priv = (struct crb_priv *) devm_kzalloc(dev, sizeof(struct crb_priv),
+						GFP_KERNEL);
+	if (!priv) {
+		dev_err(dev, "failed to devm_kzalloc for private data\n");
+		return -ENOMEM;
+	}
+
+	sm = le32_to_cpu(buf->start_method);
+
+	/* The reason for the extra quirk is that the PTT in 4th Gen Core CPUs
+	 * report only ACPI start but in practice seems to require both
+	 * ACPI start and CRB start.
+	 */
+	if (sm == CRB_SM_CRB || sm == CRB_SM_CRB_WITH_ACPI_START ||
+	    !strcmp(acpi_device_hid(device), "MSFT0101"))
+		priv->flags |= CRB_FL_CRB_START;
+
+	if (sm == CRB_SM_ACPI_START || sm == CRB_SM_CRB_WITH_ACPI_START)
+		priv->flags |= CRB_FL_ACPI_START;
+
+	priv->cca = (struct crb_control_area __iomem *)
+		devm_ioremap_nocache(dev, buf->control_area_pa, 0x1000);
+	if (!priv->cca) {
+		dev_err(dev, "ioremap of the control area failed\n");
+		return -ENOMEM;
+	}
+
+	memcpy_fromio(&pa, &priv->cca->cmd_pa, 8);
+	pa = le64_to_cpu(pa);
+	priv->cmd = devm_ioremap_nocache(dev, pa,
+					 ioread32(&priv->cca->cmd_size));
+	if (!priv->cmd) {
+		dev_err(dev, "ioremap of the command buffer failed\n");
+		return -ENOMEM;
+	}
+
+	memcpy_fromio(&pa, &priv->cca->rsp_pa, 8);
+	pa = le64_to_cpu(pa);
+	priv->rsp = devm_ioremap_nocache(dev, pa,
+					 ioread32(&priv->cca->rsp_size));
+	if (!priv->rsp) {
+		dev_err(dev, "ioremap of the response buffer failed\n");
+		return -ENOMEM;
+	}
+
+	chip->vendor.priv = priv;
+
+	/* Default timeouts and durations */
+	chip->vendor.timeout_a = msecs_to_jiffies(TPM2_TIMEOUT_A);
+	chip->vendor.timeout_b = msecs_to_jiffies(TPM2_TIMEOUT_B);
+	chip->vendor.timeout_c = msecs_to_jiffies(TPM2_TIMEOUT_C);
+	chip->vendor.timeout_d = msecs_to_jiffies(TPM2_TIMEOUT_D);
+	chip->vendor.duration[TPM_SHORT] =
+		msecs_to_jiffies(TPM2_DURATION_SHORT);
+	chip->vendor.duration[TPM_MEDIUM] =
+		msecs_to_jiffies(TPM2_DURATION_MEDIUM);
+	chip->vendor.duration[TPM_LONG] =
+		msecs_to_jiffies(TPM2_DURATION_LONG);
+
+	chip->acpi_dev_handle = device->handle;
+
+	rc = tpm2_do_selftest(chip);
+	if (rc)
+		return rc;
+
+	return tpm_chip_register(chip);
+}
+
+static int crb_acpi_remove(struct acpi_device *device)
+{
+	struct device *dev = &device->dev;
+	struct tpm_chip *chip = dev_get_drvdata(dev);
+
+	tpm_chip_unregister(chip);
+
+	if (chip->flags & TPM_CHIP_FLAG_TPM2)
+		tpm2_shutdown(chip, TPM2_SU_CLEAR);
+
+	return 0;
+}
+
+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,
+		.remove = crb_acpi_remove,
+	},
+	.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");