linux/drivers/char/tpm/tpm_ppi.c
Jarkko Sakkinen 9b774d5cf2 tpm: move the PPI attributes to character device directory.
Moved PPI attributes to the character device directory. This aligns with
the sysfs guidelines and makes them race free because they are created
atomically with the character device as part of device_register().The
character device and the sysfs attributes appear at the same time to the
user space.

As part of this change we enable PPI attributes also for TPM 2.0
devices. In order to retain backwards compatibility with TPM 1.x
devices, a symlink is created to the platform device directory.

Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Reviewed-by: Jason Gunthorpe <jason.gunthorpe@obsidianresearch.com>
Tested-by: Mimi Zohar <zohar@linux.vnet.ibm.com> (on TPM 1.2)
Tested-by: Chris J Arges <chris.j.arges@canonical.com>
Tested-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Peter Huewe <peterhuewe@gmx.de>
2015-10-19 01:01:20 +02:00

360 lines
9.5 KiB
C

/*
* 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 = to_tpm_chip(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 = to_tpm_chip(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 = to_tpm_chip(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 = to_tpm_chip(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 = to_tpm_chip(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 = to_tpm_chip(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 = to_tpm_chip(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
};
void tpm_add_ppi(struct tpm_chip *chip)
{
union acpi_object *obj;
if (!chip->acpi_dev_handle)
return;
if (!acpi_check_dsm(chip->acpi_dev_handle, tpm_ppi_uuid,
TPM_PPI_REVISION_ID, 1 << TPM_PPI_FN_VERSION))
return;
/* 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);
}
chip->groups[chip->groups_cnt++] = &ppi_attr_grp;
}