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path: root/drivers/char/tpm/tpm_ppi.c
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Diffstat (limited to 'drivers/char/tpm/tpm_ppi.c')
-rw-r--r--drivers/char/tpm/tpm_ppi.c371
1 files changed, 371 insertions, 0 deletions
diff --git a/drivers/char/tpm/tpm_ppi.c b/drivers/char/tpm/tpm_ppi.c
new file mode 100644
index 000000000..6ca9b5d78
--- /dev/null
+++ b/drivers/char/tpm/tpm_ppi.c
@@ -0,0 +1,371 @@
+/*
+ * Copyright (C) 2012-2014 Intel Corporation
+ *
+ * Authors:
+ * Xiaoyan Zhang <xiaoyan.zhang@intel.com>
+ * Jiang Liu <jiang.liu@linux.intel.com>
+ * Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
+ *
+ * Maintained by: <tpmdd-devel@lists.sourceforge.net>
+ *
+ * This file contains implementation of the sysfs interface for PPI.
+ *
+ * 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 "tpm.h"
+
+#define TPM_PPI_REVISION_ID 1
+#define TPM_PPI_FN_VERSION 1
+#define TPM_PPI_FN_SUBREQ 2
+#define TPM_PPI_FN_GETREQ 3
+#define TPM_PPI_FN_GETACT 4
+#define TPM_PPI_FN_GETRSP 5
+#define TPM_PPI_FN_SUBREQ2 7
+#define TPM_PPI_FN_GETOPR 8
+#define PPI_TPM_REQ_MAX 22
+#define PPI_VS_REQ_START 128
+#define PPI_VS_REQ_END 255
+
+static const u8 tpm_ppi_uuid[] = {
+ 0xA6, 0xFA, 0xDD, 0x3D,
+ 0x1B, 0x36,
+ 0xB4, 0x4E,
+ 0xA4, 0x24,
+ 0x8D, 0x10, 0x08, 0x9D, 0x16, 0x53
+};
+
+static inline union acpi_object *
+tpm_eval_dsm(acpi_handle ppi_handle, int func, acpi_object_type type,
+ union acpi_object *argv4)
+{
+ BUG_ON(!ppi_handle);
+ return acpi_evaluate_dsm_typed(ppi_handle, tpm_ppi_uuid,
+ TPM_PPI_REVISION_ID,
+ func, argv4, type);
+}
+
+static ssize_t tpm_show_ppi_version(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct tpm_chip *chip = dev_get_drvdata(dev);
+
+ return scnprintf(buf, PAGE_SIZE, "%s\n", chip->ppi_version);
+}
+
+static ssize_t tpm_show_ppi_request(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ ssize_t size = -EINVAL;
+ union acpi_object *obj;
+ struct tpm_chip *chip = dev_get_drvdata(dev);
+
+ obj = tpm_eval_dsm(chip->acpi_dev_handle, TPM_PPI_FN_GETREQ,
+ ACPI_TYPE_PACKAGE, NULL);
+ if (!obj)
+ return -ENXIO;
+
+ /*
+ * output.pointer should be of package type, including two integers.
+ * The first is function return code, 0 means success and 1 means
+ * error. The second is pending TPM operation requested by the OS, 0
+ * means none and >0 means operation value.
+ */
+ if (obj->package.count == 2 &&
+ obj->package.elements[0].type == ACPI_TYPE_INTEGER &&
+ obj->package.elements[1].type == ACPI_TYPE_INTEGER) {
+ if (obj->package.elements[0].integer.value)
+ size = -EFAULT;
+ else
+ size = scnprintf(buf, PAGE_SIZE, "%llu\n",
+ obj->package.elements[1].integer.value);
+ }
+
+ ACPI_FREE(obj);
+
+ return size;
+}
+
+static ssize_t tpm_store_ppi_request(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ u32 req;
+ u64 ret;
+ int func = TPM_PPI_FN_SUBREQ;
+ union acpi_object *obj, tmp;
+ union acpi_object argv4 = ACPI_INIT_DSM_ARGV4(1, &tmp);
+ struct tpm_chip *chip = dev_get_drvdata(dev);
+
+ /*
+ * the function to submit TPM operation request to pre-os environment
+ * is updated with function index from SUBREQ to SUBREQ2 since PPI
+ * version 1.1
+ */
+ if (acpi_check_dsm(chip->acpi_dev_handle, tpm_ppi_uuid,
+ TPM_PPI_REVISION_ID, 1 << TPM_PPI_FN_SUBREQ2))
+ func = TPM_PPI_FN_SUBREQ2;
+
+ /*
+ * PPI spec defines params[3].type as ACPI_TYPE_PACKAGE. Some BIOS
+ * accept buffer/string/integer type, but some BIOS accept buffer/
+ * string/package type. For PPI version 1.0 and 1.1, use buffer type
+ * for compatibility, and use package type since 1.2 according to spec.
+ */
+ if (strcmp(chip->ppi_version, "1.2") < 0) {
+ if (sscanf(buf, "%d", &req) != 1)
+ return -EINVAL;
+ argv4.type = ACPI_TYPE_BUFFER;
+ argv4.buffer.length = sizeof(req);
+ argv4.buffer.pointer = (u8 *)&req;
+ } else {
+ tmp.type = ACPI_TYPE_INTEGER;
+ if (sscanf(buf, "%llu", &tmp.integer.value) != 1)
+ return -EINVAL;
+ }
+
+ obj = tpm_eval_dsm(chip->acpi_dev_handle, func, ACPI_TYPE_INTEGER,
+ &argv4);
+ if (!obj) {
+ return -ENXIO;
+ } else {
+ ret = obj->integer.value;
+ ACPI_FREE(obj);
+ }
+
+ if (ret == 0)
+ return (acpi_status)count;
+
+ return (ret == 1) ? -EPERM : -EFAULT;
+}
+
+static ssize_t tpm_show_ppi_transition_action(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ u32 ret;
+ acpi_status status;
+ union acpi_object *obj = NULL;
+ union acpi_object tmp = {
+ .buffer.type = ACPI_TYPE_BUFFER,
+ .buffer.length = 0,
+ .buffer.pointer = NULL
+ };
+ struct tpm_chip *chip = dev_get_drvdata(dev);
+
+ static char *info[] = {
+ "None",
+ "Shutdown",
+ "Reboot",
+ "OS Vendor-specific",
+ "Error",
+ };
+
+ /*
+ * PPI spec defines params[3].type as empty package, but some platforms
+ * (e.g. Capella with PPI 1.0) need integer/string/buffer type, so for
+ * compatibility, define params[3].type as buffer, if PPI version < 1.2
+ */
+ if (strcmp(chip->ppi_version, "1.2") < 0)
+ obj = &tmp;
+ obj = tpm_eval_dsm(chip->acpi_dev_handle, TPM_PPI_FN_GETACT,
+ ACPI_TYPE_INTEGER, obj);
+ if (!obj) {
+ return -ENXIO;
+ } else {
+ ret = obj->integer.value;
+ ACPI_FREE(obj);
+ }
+
+ if (ret < ARRAY_SIZE(info) - 1)
+ status = scnprintf(buf, PAGE_SIZE, "%d: %s\n", ret, info[ret]);
+ else
+ status = scnprintf(buf, PAGE_SIZE, "%d: %s\n", ret,
+ info[ARRAY_SIZE(info)-1]);
+ return status;
+}
+
+static ssize_t tpm_show_ppi_response(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ acpi_status status = -EINVAL;
+ union acpi_object *obj, *ret_obj;
+ u64 req, res;
+ struct tpm_chip *chip = dev_get_drvdata(dev);
+
+ obj = tpm_eval_dsm(chip->acpi_dev_handle, TPM_PPI_FN_GETRSP,
+ ACPI_TYPE_PACKAGE, NULL);
+ if (!obj)
+ return -ENXIO;
+
+ /*
+ * parameter output.pointer should be of package type, including
+ * 3 integers. The first means function return code, the second means
+ * most recent TPM operation request, and the last means response to
+ * the most recent TPM operation request. Only if the first is 0, and
+ * the second integer is not 0, the response makes sense.
+ */
+ ret_obj = obj->package.elements;
+ if (obj->package.count < 3 ||
+ ret_obj[0].type != ACPI_TYPE_INTEGER ||
+ ret_obj[1].type != ACPI_TYPE_INTEGER ||
+ ret_obj[2].type != ACPI_TYPE_INTEGER)
+ goto cleanup;
+
+ if (ret_obj[0].integer.value) {
+ status = -EFAULT;
+ goto cleanup;
+ }
+
+ req = ret_obj[1].integer.value;
+ res = ret_obj[2].integer.value;
+ if (req) {
+ if (res == 0)
+ status = scnprintf(buf, PAGE_SIZE, "%llu %s\n", req,
+ "0: Success");
+ else if (res == 0xFFFFFFF0)
+ status = scnprintf(buf, PAGE_SIZE, "%llu %s\n", req,
+ "0xFFFFFFF0: User Abort");
+ else if (res == 0xFFFFFFF1)
+ status = scnprintf(buf, PAGE_SIZE, "%llu %s\n", req,
+ "0xFFFFFFF1: BIOS Failure");
+ else if (res >= 1 && res <= 0x00000FFF)
+ status = scnprintf(buf, PAGE_SIZE, "%llu %llu: %s\n",
+ req, res, "Corresponding TPM error");
+ else
+ status = scnprintf(buf, PAGE_SIZE, "%llu %llu: %s\n",
+ req, res, "Error");
+ } else {
+ status = scnprintf(buf, PAGE_SIZE, "%llu: %s\n",
+ req, "No Recent Request");
+ }
+
+cleanup:
+ ACPI_FREE(obj);
+ return status;
+}
+
+static ssize_t show_ppi_operations(acpi_handle dev_handle, char *buf, u32 start,
+ u32 end)
+{
+ int i;
+ u32 ret;
+ char *str = buf;
+ union acpi_object *obj, tmp;
+ union acpi_object argv = ACPI_INIT_DSM_ARGV4(1, &tmp);
+
+ static char *info[] = {
+ "Not implemented",
+ "BIOS only",
+ "Blocked for OS by BIOS",
+ "User required",
+ "User not required",
+ };
+
+ if (!acpi_check_dsm(dev_handle, tpm_ppi_uuid, TPM_PPI_REVISION_ID,
+ 1 << TPM_PPI_FN_GETOPR))
+ return -EPERM;
+
+ tmp.integer.type = ACPI_TYPE_INTEGER;
+ for (i = start; i <= end; i++) {
+ tmp.integer.value = i;
+ obj = tpm_eval_dsm(dev_handle, TPM_PPI_FN_GETOPR,
+ ACPI_TYPE_INTEGER, &argv);
+ if (!obj) {
+ return -ENOMEM;
+ } else {
+ ret = obj->integer.value;
+ ACPI_FREE(obj);
+ }
+
+ if (ret > 0 && ret < ARRAY_SIZE(info))
+ str += scnprintf(str, PAGE_SIZE, "%d %d: %s\n",
+ i, ret, info[ret]);
+ }
+
+ return str - buf;
+}
+
+static ssize_t tpm_show_ppi_tcg_operations(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct tpm_chip *chip = dev_get_drvdata(dev);
+
+ return show_ppi_operations(chip->acpi_dev_handle, buf, 0,
+ PPI_TPM_REQ_MAX);
+}
+
+static ssize_t tpm_show_ppi_vs_operations(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct tpm_chip *chip = dev_get_drvdata(dev);
+
+ return show_ppi_operations(chip->acpi_dev_handle, buf, PPI_VS_REQ_START,
+ PPI_VS_REQ_END);
+}
+
+static DEVICE_ATTR(version, S_IRUGO, tpm_show_ppi_version, NULL);
+static DEVICE_ATTR(request, S_IRUGO | S_IWUSR | S_IWGRP,
+ tpm_show_ppi_request, tpm_store_ppi_request);
+static DEVICE_ATTR(transition_action, S_IRUGO,
+ tpm_show_ppi_transition_action, NULL);
+static DEVICE_ATTR(response, S_IRUGO, tpm_show_ppi_response, NULL);
+static DEVICE_ATTR(tcg_operations, S_IRUGO, tpm_show_ppi_tcg_operations, NULL);
+static DEVICE_ATTR(vs_operations, S_IRUGO, tpm_show_ppi_vs_operations, NULL);
+
+static struct attribute *ppi_attrs[] = {
+ &dev_attr_version.attr,
+ &dev_attr_request.attr,
+ &dev_attr_transition_action.attr,
+ &dev_attr_response.attr,
+ &dev_attr_tcg_operations.attr,
+ &dev_attr_vs_operations.attr, NULL,
+};
+static struct attribute_group ppi_attr_grp = {
+ .name = "ppi",
+ .attrs = ppi_attrs
+};
+
+int tpm_add_ppi(struct tpm_chip *chip)
+{
+ union acpi_object *obj;
+ int rc;
+
+ if (!chip->acpi_dev_handle)
+ return 0;
+
+ if (!acpi_check_dsm(chip->acpi_dev_handle, tpm_ppi_uuid,
+ TPM_PPI_REVISION_ID, 1 << TPM_PPI_FN_VERSION))
+ return 0;
+
+ /* Cache PPI version string. */
+ obj = acpi_evaluate_dsm_typed(chip->acpi_dev_handle, tpm_ppi_uuid,
+ TPM_PPI_REVISION_ID, TPM_PPI_FN_VERSION,
+ NULL, ACPI_TYPE_STRING);
+ if (obj) {
+ strlcpy(chip->ppi_version, obj->string.pointer,
+ sizeof(chip->ppi_version));
+ ACPI_FREE(obj);
+ }
+
+ rc = sysfs_create_group(&chip->pdev->kobj, &ppi_attr_grp);
+
+ if (!rc)
+ chip->flags |= TPM_CHIP_FLAG_PPI;
+
+ return rc;
+}
+
+void tpm_remove_ppi(struct tpm_chip *chip)
+{
+ if (chip->flags & TPM_CHIP_FLAG_PPI)
+ sysfs_remove_group(&chip->pdev->kobj, &ppi_attr_grp);
+}
generated by cgit v1.2.3-54-g00ecf (git 2.45.2) at 2024-07-02 21:44:04 +0000