ACPI / TPM: replace open-coded _DSM code with helper functions
authorJiang Liu <jiang.liu@linux.intel.com>
Thu, 19 Dec 2013 12:38:17 +0000 (20:38 +0800)
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>
Sun, 5 Jan 2014 15:07:14 +0000 (16:07 +0100)
Use helper functions to simplify _DSM related code in TPM driver.

This patch also help to get rid of following warning messages:
[  163.509575] ACPI Error: Incorrect return type [Buffer] requested [Package]
(20130517/nsxfeval-135)

But there is still an warning left.
[  181.637366] ACPI Warning: \_SB_.IIO0.LPC0.TPM_._DSM: Argument #4 type
mismatch - Found [Buffer], ACPI requires [Package] (20130517/nsarguments-95)

Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
drivers/char/tpm/tpm_ppi.c

index 1e9cc11ac76afb1ed2cfd4930fac5737ac309122..d542ac6d0ae03099bd8d8c71e842d94315b2de09 100644 (file)
@@ -2,15 +2,6 @@
 #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
@@ -24,250 +15,185 @@ static char *tpm_device_name = "TPM";
 #define PPI_VS_REQ_END         255
 #define PPI_VERSION_LEN                3
 
+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";
+static char tpm_ppi_version[PPI_VERSION_LEN + 1];
+static acpi_handle tpm_ppi_handle;
+
 static acpi_status ppi_callback(acpi_handle handle, u32 level, void *context,
                                void **return_value)
 {
        acpi_status status = AE_OK;
        struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 
-       if (ACPI_SUCCESS(acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer))) {
-               if (strstr(buffer.pointer, context) != NULL) {
-                       *return_value = handle;
-                       status = AE_CTRL_TERMINATE;
+       status = acpi_get_name(handle, ACPI_SINGLE_NAME, &buffer);
+       if (ACPI_FAILURE(status))
+               return AE_OK;
+
+       if (strstr(buffer.pointer, context) != NULL) {
+               union acpi_object *obj;
+
+               /* Cache version string */
+               obj = acpi_evaluate_dsm_typed(handle, tpm_ppi_uuid,
+                               TPM_PPI_REVISION_ID, TPM_PPI_FN_VERSION,
+                               NULL, ACPI_TYPE_STRING);
+               if (obj) {
+                       strlcpy(tpm_ppi_version, obj->string.pointer,
+                               PPI_VERSION_LEN + 1);
+                       ACPI_FREE(obj);
                }
-               kfree(buffer.pointer);
+
+               *return_value = handle;
+               status = AE_CTRL_TERMINATE;
        }
+       kfree(buffer.pointer);
 
        return status;
 }
 
-static inline void ppi_assign_params(union acpi_object params[4],
-                                    u64 function_num)
+static inline union acpi_object *
+tpm_eval_dsm(int func, acpi_object_type type, union acpi_object *argv4)
 {
-       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;
+       BUG_ON(!tpm_ppi_handle);
+       return acpi_evaluate_dsm_typed(tpm_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)
 {
-       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;
+       return scnprintf(buf, PAGE_SIZE, "%s\n", tpm_ppi_version);
 }
 
 static 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))
+       ssize_t size = -EINVAL;
+       union acpi_object *obj;
+
+       obj = tpm_eval_dsm(TPM_PPI_FN_GETREQ, ACPI_TYPE_PACKAGE, NULL);
+       if (!obj)
                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);
+       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
-                       status = -EINVAL;
-       } else {
-               status = -EINVAL;
+                       size = scnprintf(buf, PAGE_SIZE, "%llu\n",
+                                obj->package.elements[1].integer.value);
        }
-cleanup:
-       kfree(output.pointer);
-       return status;
+
+       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)
 {
-       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;
+       int func = TPM_PPI_FN_SUBREQ;
+       union acpi_object *obj, tmp;
+       union acpi_object argv4 = ACPI_INIT_DSM_ARGV4(1, &tmp);
 
-       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;
-       strlcpy(version,
-               ((union acpi_object *)output.pointer)->string.pointer,
-               PPI_VERSION_LEN + 1);
-       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;
+       if (strcmp(tpm_ppi_version, "1.1") >= 0)
+               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(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;
+       if (strcmp(tpm_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 {
-               params[3].package.count = 1;
-               obj.type = ACPI_TYPE_INTEGER;
-               sscanf(buf, "%llu", &obj.integer.value);
-               params[3].package.elements = &obj;
+               tmp.type = ACPI_TYPE_INTEGER;
+               if (sscanf(buf, "%llu", &tmp.integer.value) != 1)
+                       return -EINVAL;
+       }
+
+       obj = tpm_eval_dsm(func, ACPI_TYPE_INTEGER, &argv4);
+       if (!obj) {
+               return -ENXIO;
+       } else {
+               ret = obj->integer.value;
+               ACPI_FREE(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;
+               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)
 {
-       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[] = {
+       acpi_status status;
+       union acpi_object *obj = NULL;
+       union acpi_object tmp = {
+               .buffer.type = ACPI_TYPE_BUFFER,
+               .buffer.length = 0,
+               .buffer.pointer = NULL
+       };
+
+       static 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;
-       strlcpy(version,
-               ((union acpi_object *)output.pointer)->string.pointer,
-               PPI_VERSION_LEN + 1);
        /*
         * 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;
+       if (strcmp(tpm_ppi_version, "1.2") < 0)
+               obj = &tmp;
+       obj = tpm_eval_dsm(TPM_PPI_FN_GETACT, ACPI_TYPE_INTEGER, obj);
+       if (!obj) {
+               return -ENXIO;
+       } else {
+               ret = obj->integer.value;
+               ACPI_FREE(obj);
        }
-       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;
 }
 
@@ -275,27 +201,14 @@ static 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))
+       acpi_status status = -EINVAL;
+       union acpi_object *obj, *ret_obj;
+       u64 req, res;
+
+       obj = tpm_eval_dsm(TPM_PPI_FN_GETRSP, ACPI_TYPE_PACKAGE, NULL);
+       if (!obj)
                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
@@ -303,115 +216,81 @@ static ssize_t tpm_show_ppi_response(struct device *dev,
         * 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;
+       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->integer.value) {
+
+       if (ret_obj[0].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)
+
+       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 (ret_obj->integer.value == 0xFFFFFFF0)
+               else if (res == 0xFFFFFFF0)
                        status = scnprintf(buf, PAGE_SIZE, "%llu %s\n", req,
                                           "0xFFFFFFF0: User Abort");
-               else if (ret_obj->integer.value == 0xFFFFFFF1)
+               else if (res == 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)
+               else if (res >= 1 && res <= 0x00000FFF)
                        status = scnprintf(buf, PAGE_SIZE, "%llu %llu: %s\n",
-                                          req, ret_obj->integer.value,
-                                          "Corresponding TPM error");
+                                          req, res, "Corresponding TPM error");
                else
                        status = scnprintf(buf, PAGE_SIZE, "%llu %llu: %s\n",
-                                          req, ret_obj->integer.value,
-                                          "Error");
+                                          req, res, "Error");
        } else {
                status = scnprintf(buf, PAGE_SIZE, "%llu: %s\n",
-                                  ret_obj->integer.value, "No Recent Request");
+                                  req, "No Recent Request");
        }
+
 cleanup:
-       kfree(output.pointer);
+       ACPI_FREE(obj);
        return status;
 }
 
 static ssize_t show_ppi_operations(char *buf, u32 start, u32 end)
 {
-       char *str = 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];
-       union acpi_object obj;
        int i;
        u32 ret;
-       char *info[] = {
+       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",
        };
-       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;
-
-       strlcpy(version,
-               ((union acpi_object *)output.pointer)->string.pointer,
-               PPI_VERSION_LEN + 1);
-       kfree(output.pointer);
-       output.length = ACPI_ALLOCATE_BUFFER;
-       output.pointer = NULL;
-       if (strcmp(version, "1.2") == -1)
+       if (strcmp(tpm_ppi_version, "1.2") < 0)
                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;
+       tmp.integer.type = ACPI_TYPE_INTEGER;
        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))
+               tmp.integer.value = i;
+               obj = tpm_eval_dsm(TPM_PPI_FN_GETOPR, ACPI_TYPE_INTEGER, &argv);
+               if (!obj) {
                        return -ENOMEM;
+               } else {
+                       ret = obj->integer.value;
+                       ACPI_FREE(obj);
+               }
 
-               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;
 }
 
@@ -453,6 +332,13 @@ static struct attribute_group ppi_attr_grp = {
 
 int tpm_add_ppi(struct kobject *parent)
 {
+       /* Cache TPM ACPI handle and version string */
+       acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT, ACPI_UINT32_MAX,
+                           ppi_callback, NULL,
+                           tpm_device_name, &tpm_ppi_handle);
+       if (tpm_ppi_handle == NULL)
+               return -ENODEV;
+
        return sysfs_create_group(parent, &ppi_attr_grp);
 }