tpm: Clean up reading of timeout and duration capabilities

Call tpm_getcap() from tpm_get_timeouts() to eliminate redundant
code. Return all errors to the caller rather than swallowing them
(e.g. when tpm_transmit_cmd() returns nonzero).

Signed-off-by: Ed Swierk <eswierk@skyportsystems.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>

1 files changed, 17 insertions, 48 deletions

diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
index cb0e57ee053d..acf89e8d838e 100644
--- a/drivers/char/tpm/tpm-interface.c
+++ b/drivers/char/tpm/tpm-interface.c
@@ -493,10 +493,9 @@ static int tpm_startup(struct tpm_chip *chip, __be16 startup_type)
 
 int tpm_get_timeouts(struct tpm_chip *chip)
 {
-        struct tpm_cmd_t tpm_cmd;
+        cap_t cap;
         unsigned long new_timeout[4];
         unsigned long old_timeout[4];
-        struct duration_t *duration_cap;
         ssize_t rc;
 
         if (chip->flags & TPM_CHIP_FLAG_TPM2) {
@@ -514,43 +513,25 @@ int tpm_get_timeouts(struct tpm_chip *chip)
                 return 0;
         }
 
-        tpm_cmd.header.in = tpm_getcap_header;
-        tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
-        tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
-        tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_TIMEOUT;
-        rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, 0,
-                              NULL);
-
+        rc = tpm_getcap(chip, TPM_CAP_PROP_TIS_TIMEOUT, &cap,
+                        "attempting to determine the timeouts");
         if (rc == TPM_ERR_INVALID_POSTINIT) {
                 /* The TPM is not started, we are the first to talk to it.
                    Execute a startup command. */
-                dev_info(&chip->dev, "Issuing TPM_STARTUP");
+                dev_info(&chip->dev, "Issuing TPM_STARTUP\n");
                 if (tpm_startup(chip, TPM_ST_CLEAR))
                         return rc;
 
-                tpm_cmd.header.in = tpm_getcap_header;
-                tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
-                tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
-                tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_TIMEOUT;
-                rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE,
-                                      0, NULL);
+                rc = tpm_getcap(chip, TPM_CAP_PROP_TIS_TIMEOUT, &cap,
+                                "attempting to determine the timeouts");
         }
-        if (rc) {
-                dev_err(&chip->dev,
-                        "A TPM error (%zd) occurred attempting to determine the timeouts\n",
-                        rc);
-                goto duration;
-        }
-
-        if (be32_to_cpu(tpm_cmd.header.out.return_code) != 0 ||
-            be32_to_cpu(tpm_cmd.header.out.length)
-            != sizeof(tpm_cmd.header.out) + sizeof(u32) + 4 * sizeof(u32))
-                return -EINVAL;
+        if (rc)
+                return rc;
 
-        old_timeout[0] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.a);
-        old_timeout[1] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.b);
-        old_timeout[2] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.c);
-        old_timeout[3] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.d);
+        old_timeout[0] = be32_to_cpu(cap.timeout.a);
+        old_timeout[1] = be32_to_cpu(cap.timeout.b);
+        old_timeout[2] = be32_to_cpu(cap.timeout.c);
+        old_timeout[3] = be32_to_cpu(cap.timeout.d);
         memcpy(new_timeout, old_timeout, sizeof(new_timeout));
 
         /*
@@ -588,29 +569,17 @@ int tpm_get_timeouts(struct tpm_chip *chip)
         chip->timeout_c = usecs_to_jiffies(new_timeout[2]);
         chip->timeout_d = usecs_to_jiffies(new_timeout[3]);
 
-duration:
-        tpm_cmd.header.in = tpm_getcap_header;
-        tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
-        tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
-        tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_DURATION;
-
-        rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, 0,
-                              "attempting to determine the durations");
+        rc = tpm_getcap(chip, TPM_CAP_PROP_TIS_DURATION, &cap,
+                        "attempting to determine the durations");
         if (rc)
                 return rc;
 
-        if (be32_to_cpu(tpm_cmd.header.out.return_code) != 0 ||
-            be32_to_cpu(tpm_cmd.header.out.length)
-            != sizeof(tpm_cmd.header.out) + sizeof(u32) + 3 * sizeof(u32))
-                return -EINVAL;
-
-        duration_cap = &tpm_cmd.params.getcap_out.cap.duration;
         chip->duration[TPM_SHORT] =
-            usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_short));
+                usecs_to_jiffies(be32_to_cpu(cap.duration.tpm_short));
         chip->duration[TPM_MEDIUM] =
-            usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_medium));
+                usecs_to_jiffies(be32_to_cpu(cap.duration.tpm_medium));
         chip->duration[TPM_LONG] =
-            usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_long));
+                usecs_to_jiffies(be32_to_cpu(cap.duration.tpm_long));
 
         /* The Broadcom BCM0102 chipset in a Dell Latitude D820 gets the above
          * value wrong and apparently reports msecs rather than usecs. So we