diff options
Diffstat (limited to 'drivers/char/tpm/tpm_ppi.c')
| -rw-r--r-- | drivers/char/tpm/tpm_ppi.c | 460 |
1 files changed, 460 insertions, 0 deletions
diff --git a/drivers/char/tpm/tpm_ppi.c b/drivers/char/tpm/tpm_ppi.c new file mode 100644 index 000000000000..440fa1c2d301 --- /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"); |