tpm: migrate tpm2_shutdown() to use struct tpm_buf

In order to make struct tpm_buf the first class object for constructing TPM
commands, migrated tpm2_shutdown() to use it.

Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Reviewed-by: Nayna Jain <nayna@linux.vnet.ibm.com>
Tested-by: Nayna Jain <nayna@linux.vnet.ibm.com>
Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com>

diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c
index d31b090..026fec4 100644 (file)
--- a/drivers/char/tpm/tpm2-cmd.c
+++ b/drivers/char/tpm/tpm2-cmd.c
@@ -27,10 +27,6 @@ enum tpm2_session_attributes {
        TPM2_SA_CONTINUE_SESSION        = BIT(0),
 };
 
-struct tpm2_startup_in {
-       __be16  startup_type;
-} __packed;
-
 struct tpm2_get_tpm_pt_in {
        __be32  cap_id;
        __be32  property_id;
@@ -55,7 +51,6 @@ struct tpm2_get_random_out {
 } __packed;
 
 union tpm2_cmd_params {
-       struct  tpm2_startup_in         startup_in;
        struct  tpm2_get_tpm_pt_in      get_tpm_pt_in;
        struct  tpm2_get_tpm_pt_out     get_tpm_pt_out;
        struct  tpm2_get_random_in      getrandom_in;
@@ -762,40 +757,28 @@ ssize_t tpm2_get_tpm_pt(struct tpm_chip *chip, u32 property_id,  u32 *value,
 }
 EXPORT_SYMBOL_GPL(tpm2_get_tpm_pt);
 
-#define TPM2_SHUTDOWN_IN_SIZE \
-       (sizeof(struct tpm_input_header) + \
-        sizeof(struct tpm2_startup_in))
-
-static const struct tpm_input_header tpm2_shutdown_header = {
-       .tag = cpu_to_be16(TPM2_ST_NO_SESSIONS),
-       .length = cpu_to_be32(TPM2_SHUTDOWN_IN_SIZE),
-       .ordinal = cpu_to_be32(TPM2_CC_SHUTDOWN)
-};
-
 /**
- * tpm2_shutdown() - send shutdown command to the TPM chip
+ * tpm2_shutdown() - send a TPM shutdown command
  *
- * @chip:              TPM chip to use.
- * @shutdown_type:     shutdown type. The value is either
- *                     TPM_SU_CLEAR or TPM_SU_STATE.
+ * Sends a TPM shutdown command. The shutdown command is used in call
+ * sites where the system is going down. If it fails, there is not much
+ * that can be done except print an error message.
+ *
+ * @chip:              a &tpm_chip instance
+ * @shutdown_type:     TPM_SU_CLEAR or TPM_SU_STATE.
  */
 void tpm2_shutdown(struct tpm_chip *chip, u16 shutdown_type)
 {
-       struct tpm2_cmd cmd;
+       struct tpm_buf buf;
        int rc;
 
-       cmd.header.in = tpm2_shutdown_header;
-       cmd.params.startup_in.startup_type = cpu_to_be16(shutdown_type);
-
-       rc = tpm_transmit_cmd(chip, NULL, &cmd, sizeof(cmd), 0, 0,
-                             "stopping the TPM");
-
-       /* In places where shutdown command is sent there's no much we can do
-        * except print the error code on a system failure.
-        */
-       if (rc < 0 && rc != -EPIPE)
-               dev_warn(&chip->dev, "transmit returned %d while stopping the TPM",
-                        rc);
+       rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_SHUTDOWN);
+       if (rc)
+               return;
+       tpm_buf_append_u16(&buf, shutdown_type);
+       tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE, 0, 0,
+                        "stopping the TPM");
+       tpm_buf_destroy(&buf);
 }
 
 /*