diff options
author | André Fabian Silva Delgado <emulatorman@parabola.nu> | 2015-08-05 17:04:01 -0300 |
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committer | André Fabian Silva Delgado <emulatorman@parabola.nu> | 2015-08-05 17:04:01 -0300 |
commit | 57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch) | |
tree | 5e910f0e82173f4ef4f51111366a3f1299037a7b /drivers/char/tpm/tpm_ppi.c |
Initial import
Diffstat (limited to 'drivers/char/tpm/tpm_ppi.c')
-rw-r--r-- | drivers/char/tpm/tpm_ppi.c | 371 |
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); +} |