From: Xiaoyan Zhang <xiaoyan.zh...@intel.com>
The Physical Presence Interface enables the OS and the BIOS to cooperate and
provides a simple and straightforward platform user experience for
administering the TPM without sacrificing security.
V2: separate the patch out in a separate source file,
add #ifdef CONFIG_ACPI so it compiles out on ppc,
use standard error instead of ACPI error as return code of show/store fns.
V3: move #ifdef CONFIG_ACPI from .c file to .h file.
V4: move tpm_ppi code from tpm module to tpm_bios module.
V5: modify sys_add_ppi() so that ppi_attr_grp doesn't need to be exported
Signed-off-by: Xiaoyan Zhang <xiaoyan.zh...@intel.com>
---
drivers/char/tpm/Makefile | 2 +-
drivers/char/tpm/tpm.c | 5 +
drivers/char/tpm/tpm.h | 9 +
drivers/char/tpm/tpm_ppi.c | 460 ++++++++++++++++++++++++++++++++++++++++++++
4 files changed, 475 insertions(+), 1 deletions(-)
create mode 100644 drivers/char/tpm/tpm_ppi.c
diff --git a/drivers/char/tpm/Makefile b/drivers/char/tpm/Makefile
index 9080cc4..5b3fc8b 100644
--- a/drivers/char/tpm/Makefile
+++ b/drivers/char/tpm/Makefile
@@ -4,7 +4,7 @@
obj-$(CONFIG_TCG_TPM) += tpm.o
ifdef CONFIG_ACPI
obj-$(CONFIG_TCG_TPM) += tpm_bios.o
- tpm_bios-objs += tpm_eventlog.o tpm_acpi.o
+ tpm_bios-objs += tpm_eventlog.o tpm_acpi.o tpm_ppi.o
else
ifdef CONFIG_TCG_IBMVTPM
obj-$(CONFIG_TCG_TPM) += tpm_bios.o
diff --git a/drivers/char/tpm/tpm.c b/drivers/char/tpm/tpm.c
index 0a75638..39526c0 100644
--- a/drivers/char/tpm/tpm.c
+++ b/drivers/char/tpm/tpm.c
@@ -1476,6 +1476,11 @@ struct tpm_chip *tpm_register_hardware(struct device
*dev,
goto put_device;
}
+ if (sys_add_ppi(&dev->kobj)) {
+ misc_deregister(&chip->vendor.miscdev);
+ goto put_device;
+ }
+
chip->bios_dir = tpm_bios_log_setup(devname);
/* Make chip available */
diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
index f1af738..02c266a 100644
--- a/drivers/char/tpm/tpm.h
+++ b/drivers/char/tpm/tpm.h
@@ -327,3 +327,12 @@ extern int tpm_pm_suspend(struct device *);
extern int tpm_pm_resume(struct device *);
extern int wait_for_tpm_stat(struct tpm_chip *, u8, unsigned long,
wait_queue_head_t *);
+
+#ifdef CONFIG_ACPI
+extern ssize_t sys_add_ppi(struct kobject *parent);
+#else
+static inline ssize_t sys_add_ppi(struct kobject *parent)
+{
+ return 0;
+}
+#endif
diff --git a/drivers/char/tpm/tpm_ppi.c b/drivers/char/tpm/tpm_ppi.c
new file mode 100644
index 0000000..440fa1c
--- /dev/null
+++ b/drivers/char/tpm/tpm_ppi.c
@@ -0,0 +1,460 @@
+#include <linux/acpi.h>
+#include <acpi/acpi_drivers.h>
+#include "tpm.h"
+
+static const u8 tpm_ppi_uuid[] = {
+ 0xA6, 0xFA, 0xDD, 0x3D,
+ 0x1B, 0x36,
+ 0xB4, 0x4E,
+ 0xA4, 0x24,
+ 0x8D, 0x10, 0x08, 0x9D, 0x16, 0x53
+};
+static char *tpm_device_name = "TPM";
+
+#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
+#define PPI_VERSION_LEN 3
+
+static acpi_status ppi_callback(acpi_handle handle, u32 level, void *context,
+ void **return_value)
+{
+ acpi_status status;
+ struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
+ status = acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
+ if (strstr(buffer.pointer, context) != NULL) {
+ *return_value = handle;
+ kfree(buffer.pointer);
+ return AE_CTRL_TERMINATE;
+ }
+ return AE_OK;
+}
+
+static inline void ppi_assign_params(union acpi_object params[4],
+ u64 function_num)
+{
+ params[0].type = ACPI_TYPE_BUFFER;
+ params[0].buffer.length = sizeof(tpm_ppi_uuid);
+ params[0].buffer.pointer = (char *)tpm_ppi_uuid;
+ params[1].type = ACPI_TYPE_INTEGER;
+ params[1].integer.value = TPM_PPI_REVISION_ID;
+ params[2].type = ACPI_TYPE_INTEGER;
+ params[2].integer.value = function_num;
+ params[3].type = ACPI_TYPE_PACKAGE;
+ params[3].package.count = 0;
+ params[3].package.elements = NULL;
+}
+
+ssize_t tpm_show_ppi_version(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ acpi_handle handle;
+ acpi_status status;
+ struct acpi_object_list input;
+ struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL };
+ union acpi_object params[4];
+ union acpi_object *obj;
+
+ input.count = 4;
+ ppi_assign_params(params, TPM_PPI_FN_VERSION);
+ input.pointer = params;
+ status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
+ ACPI_UINT32_MAX, ppi_callback, NULL,
+ tpm_device_name, &handle);
+ if (ACPI_FAILURE(status))
+ return -ENXIO;
+
+ status = acpi_evaluate_object_typed(handle, "_DSM", &input, &output,
+ ACPI_TYPE_STRING);
+ if (ACPI_FAILURE(status))
+ return -ENOMEM;
+ obj = (union acpi_object *)output.pointer;
+ status = scnprintf(buf, PAGE_SIZE, "%s\n", obj->string.pointer);
+ kfree(output.pointer);
+ return status;
+}
+
+ssize_t tpm_show_ppi_request(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ acpi_handle handle;
+ acpi_status status;
+ struct acpi_object_list input;
+ struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL };
+ union acpi_object params[4];
+ union acpi_object *ret_obj;
+
+ input.count = 4;
+ ppi_assign_params(params, TPM_PPI_FN_GETREQ);
+ input.pointer = params;
+ status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
+ ACPI_UINT32_MAX, ppi_callback, NULL,
+ tpm_device_name, &handle);
+ if (ACPI_FAILURE(status))
+ return -ENXIO;
+
+ status = acpi_evaluate_object_typed(handle, "_DSM", &input, &output,
+ ACPI_TYPE_PACKAGE);
+ if (ACPI_FAILURE(status))
+ return -ENOMEM;
+ /*
+ * 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.
+ */
+ ret_obj = ((union acpi_object *)output.pointer)->package.elements;
+ if (ret_obj->type == ACPI_TYPE_INTEGER) {
+ if (ret_obj->integer.value) {
+ status = -EFAULT;
+ goto cleanup;
+ }
+ ret_obj++;
+ if (ret_obj->type == ACPI_TYPE_INTEGER)
+ status = scnprintf(buf, PAGE_SIZE, "%llu\n",
+ ret_obj->integer.value);
+ else
+ status = -EINVAL;
+ } else {
+ status = -EINVAL;
+ }
+cleanup:
+ kfree(output.pointer);
+ return status;
+}
+
+ssize_t tpm_store_ppi_request(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ char version[PPI_VERSION_LEN + 1];
+ acpi_handle handle;
+ acpi_status status;
+ struct acpi_object_list input;
+ struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL };
+ union acpi_object params[4];
+ union acpi_object obj;
+ u32 req;
+ u64 ret;
+
+ input.count = 4;
+ ppi_assign_params(params, TPM_PPI_FN_VERSION);
+ input.pointer = params;
+ status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
+ ACPI_UINT32_MAX, ppi_callback, NULL,
+ tpm_device_name, &handle);
+ if (ACPI_FAILURE(status))
+ return -ENXIO;
+
+ status = acpi_evaluate_object_typed(handle, "_DSM", &input, &output,
+ ACPI_TYPE_STRING);
+ if (ACPI_FAILURE(status))
+ return -ENOMEM;
+ strncpy(version,
+ ((union acpi_object *)output.pointer)->string.pointer,
+ PPI_VERSION_LEN);
+ kfree(output.pointer);
+ output.length = ACPI_ALLOCATE_BUFFER;
+ output.pointer = NULL;
+ /*
+ * 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 (strcmp(version, "1.1") == -1)
+ params[2].integer.value = TPM_PPI_FN_SUBREQ;
+ else
+ params[2].integer.value = 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(version, "1.2") == -1) {
+ params[3].type = ACPI_TYPE_BUFFER;
+ params[3].buffer.length = sizeof(req);
+ sscanf(buf, "%d", &req);
+ params[3].buffer.pointer = (char *)&req;
+ } else {
+ params[3].package.count = 1;
+ obj.type = ACPI_TYPE_INTEGER;
+ sscanf(buf, "%llu", &obj.integer.value);
+ params[3].package.elements = &obj;
+ }
+
+ status = acpi_evaluate_object_typed(handle, "_DSM", &input, &output,
+ ACPI_TYPE_INTEGER);
+ if (ACPI_FAILURE(status))
+ return -ENOMEM;
+ ret = ((union acpi_object *)output.pointer)->integer.value;
+ if (ret == 0)
+ status = (acpi_status)count;
+ else if (ret == 1)
+ status = -EPERM;
+ else
+ status = -EFAULT;
+ kfree(output.pointer);
+ return status;
+}
+
+ssize_t tpm_show_ppi_transition_action(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ char version[PPI_VERSION_LEN + 1];
+ acpi_handle handle;
+ acpi_status status;
+ struct acpi_object_list input;
+ struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL };
+ union acpi_object params[4];
+ u32 ret;
+ char *info[] = {
+ "None",
+ "Shutdown",
+ "Reboot",
+ "OS Vendor-specific",
+ "Error",
+ };
+ input.count = 4;
+ ppi_assign_params(params, TPM_PPI_FN_VERSION);
+ input.pointer = params;
+ status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
+ ACPI_UINT32_MAX, ppi_callback, NULL,
+ tpm_device_name, &handle);
+ if (ACPI_FAILURE(status))
+ return -ENXIO;
+
+ status = acpi_evaluate_object_typed(handle, "_DSM", &input, &output,
+ ACPI_TYPE_STRING);
+ if (ACPI_FAILURE(status))
+ return -ENOMEM;
+ strncpy(version,
+ ((union acpi_object *)output.pointer)->string.pointer,
+ PPI_VERSION_LEN);
+ /*
+ * 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(version, "1.2") == -1) {
+ params[3].type = ACPI_TYPE_BUFFER;
+ params[3].buffer.length = 0;
+ params[3].buffer.pointer = NULL;
+ }
+ params[2].integer.value = TPM_PPI_FN_GETACT;
+ kfree(output.pointer);
+ output.length = ACPI_ALLOCATE_BUFFER;
+ output.pointer = NULL;
+ status = acpi_evaluate_object_typed(handle, "_DSM", &input, &output,
+ ACPI_TYPE_INTEGER);
+ if (ACPI_FAILURE(status))
+ return -ENOMEM;
+ ret = ((union acpi_object *)output.pointer)->integer.value;
+ 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]);
+ kfree(output.pointer);
+ return status;
+}
+
+ssize_t tpm_show_ppi_response(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ acpi_handle handle;
+ acpi_status status;
+ struct acpi_object_list input;
+ struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL };
+ union acpi_object params[4];
+ union acpi_object *ret_obj;
+ u64 req;
+
+ input.count = 4;
+ ppi_assign_params(params, TPM_PPI_FN_GETRSP);
+ input.pointer = params;
+ status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
+ ACPI_UINT32_MAX, ppi_callback, NULL,
+ tpm_device_name, &handle);
+ if (ACPI_FAILURE(status))
+ return -ENXIO;
+
+ status = acpi_evaluate_object_typed(handle, "_DSM", &input, &output,
+ ACPI_TYPE_PACKAGE);
+ if (ACPI_FAILURE(status))
+ return -ENOMEM;
+ /*
+ * 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 = ((union acpi_object *)output.pointer)->package.elements;
+ if (ret_obj->type != ACPI_TYPE_INTEGER) {
+ status = -EINVAL;
+ goto cleanup;
+ }
+ if (ret_obj->integer.value) {
+ status = -EFAULT;
+ goto cleanup;
+ }
+ ret_obj++;
+ if (ret_obj->type != ACPI_TYPE_INTEGER) {
+ status = -EINVAL;
+ goto cleanup;
+ }
+ if (ret_obj->integer.value) {
+ req = ret_obj->integer.value;
+ ret_obj++;
+ if (ret_obj->type != ACPI_TYPE_INTEGER) {
+ status = -EINVAL;
+ goto cleanup;
+ }
+ if (ret_obj->integer.value == 0)
+ status = scnprintf(buf, PAGE_SIZE, "%llu %s\n", req,
+ "0: Success");
+ else if (ret_obj->integer.value == 0xFFFFFFF0)
+ status = scnprintf(buf, PAGE_SIZE, "%llu %s\n", req,
+ "0xFFFFFFF0: User Abort");
+ else if (ret_obj->integer.value == 0xFFFFFFF1)
+ status = scnprintf(buf, PAGE_SIZE, "%llu %s\n", req,
+ "0xFFFFFFF1: BIOS Failure");
+ else if (ret_obj->integer.value >= 1 &&
+ ret_obj->integer.value <= 0x00000FFF)
+ status = scnprintf(buf, PAGE_SIZE, "%llu %llu: %s\n",
+ req, ret_obj->integer.value,
+ "Corresponding TPM error");
+ else
+ status = scnprintf(buf, PAGE_SIZE, "%llu %llu: %s\n",
+ req, ret_obj->integer.value,
+ "Error");
+ } else {
+ status = scnprintf(buf, PAGE_SIZE, "%llu: %s\n",
+ ret_obj->integer.value, "No Recent Request");
+ }
+cleanup:
+ kfree(output.pointer);
+ return status;
+}
+
+static ssize_t show_ppi_operations(char *buf, u32 start, u32 end)
+{
+ char *str = buf;
+ char version[PPI_VERSION_LEN];
+ acpi_handle handle;
+ acpi_status status;
+ struct acpi_object_list input;
+ struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL };
+ union acpi_object params[4];
+ union acpi_object obj;
+ int i;
+ u32 ret;
+ char *info[] = {
+ "Not implemented",
+ "BIOS only",
+ "Blocked for OS by BIOS",
+ "User required",
+ "User not required",
+ };
+ input.count = 4;
+ ppi_assign_params(params, TPM_PPI_FN_VERSION);
+ input.pointer = params;
+ status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
+ ACPI_UINT32_MAX, ppi_callback, NULL,
+ tpm_device_name, &handle);
+ if (ACPI_FAILURE(status))
+ return -ENXIO;
+
+ status = acpi_evaluate_object_typed(handle, "_DSM", &input, &output,
+ ACPI_TYPE_STRING);
+ if (ACPI_FAILURE(status))
+ return -ENOMEM;
+
+ strncpy(version,
+ ((union acpi_object *)output.pointer)->string.pointer,
+ PPI_VERSION_LEN);
+ kfree(output.pointer);
+ output.length = ACPI_ALLOCATE_BUFFER;
+ output.pointer = NULL;
+ if (strcmp(version, "1.2") == -1)
+ return -EPERM;
+
+ params[2].integer.value = TPM_PPI_FN_GETOPR;
+ params[3].package.count = 1;
+ obj.type = ACPI_TYPE_INTEGER;
+ params[3].package.elements = &obj;
+ for (i = start; i <= end; i++) {
+ obj.integer.value = i;
+ status = acpi_evaluate_object_typed(handle, "_DSM",
+ &input, &output, ACPI_TYPE_INTEGER);
+ if (ACPI_FAILURE(status))
+ return -ENOMEM;
+
+ ret = ((union acpi_object *)output.pointer)->integer.value;
+ if (ret > 0 && ret < ARRAY_SIZE(info))
+ str += scnprintf(str, PAGE_SIZE, "%d %d: %s\n",
+ i, ret, info[ret]);
+ kfree(output.pointer);
+ output.length = ACPI_ALLOCATE_BUFFER;
+ output.pointer = NULL;
+ }
+ return str - buf;
+}
+
+ssize_t tpm_show_ppi_tcg_operations(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ return show_ppi_operations(buf, 0, PPI_TPM_REQ_MAX);
+}
+
+ssize_t tpm_show_ppi_vs_operations(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ return show_ppi_operations(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 = {
+ .attrs = ppi_attrs
+};
+
+ssize_t sys_add_ppi(struct kobject *parent)
+{
+ struct kobject *ppi;
+ ppi = kobject_create_and_add("ppi", parent);
+ if (sysfs_create_group(ppi, &ppi_attr_grp))
+ return -EFAULT;
+ else
+ return 0;
+}
+EXPORT_SYMBOL_GPL(sys_add_ppi);
+
+MODULE_LICENSE("GPL");
--
1.7.7.6
--
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