Re: [PATCH v7 11/21] tpm: factor out tpm 1.x pm suspend flow into tpm1-cmd.c
From: Jarkko Sakkinen
Date: Tue Oct 23 2018 - 14:43:26 EST
On Fri, 19 Oct 2018, Tomas Winkler wrote:
Factor out TPM 1.x suspend flow from tpm-interface.c into a new function
tpm1_pm_suspend() in tpm1-cmd.c
Signed-off-by: Tomas Winkler <tomas.winkler@xxxxxxxxx>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx>
---
V2-V3: Rebase.
V4: 1. Add kdoc for tpm1_pm_suspend().
2. Fix commit message.
V5: Adjust the kdoc to the new standard.
V6: Rebase.
V7: Resend.
drivers/char/tpm/tpm-interface.c | 55 ++++--------------------------------
drivers/char/tpm/tpm.h | 2 ++
drivers/char/tpm/tpm1-cmd.c | 61 ++++++++++++++++++++++++++++++++++++++++
3 files changed, 68 insertions(+), 50 deletions(-)
diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
index 43d3540a7875..e7f220f691f9 100644
--- a/drivers/char/tpm/tpm-interface.c
+++ b/drivers/char/tpm/tpm-interface.c
@@ -586,15 +586,6 @@ int tpm_send(struct tpm_chip *chip, void *cmd, size_t buflen)
}
EXPORT_SYMBOL_GPL(tpm_send);
-#define TPM_ORD_SAVESTATE 152
-#define SAVESTATE_RESULT_SIZE 10
-
-static const struct tpm_input_header savestate_header = {
- .tag = cpu_to_be16(TPM_TAG_RQU_COMMAND),
- .length = cpu_to_be32(10),
- .ordinal = cpu_to_be32(TPM_ORD_SAVESTATE)
-};
-
/*
* We are about to suspend. Save the TPM state
* so that it can be restored.
@@ -602,54 +593,18 @@ static const struct tpm_input_header savestate_header = {
int tpm_pm_suspend(struct device *dev)
{
struct tpm_chip *chip = dev_get_drvdata(dev);
- struct tpm_cmd_t cmd;
- int rc, try;
-
- u8 dummy_hash[TPM_DIGEST_SIZE] = { 0 };
+ int rc = 0;
- if (chip == NULL)
+ if (!chip)
return -ENODEV;
if (chip->flags & TPM_CHIP_FLAG_ALWAYS_POWERED)
return 0;
- if (chip->flags & TPM_CHIP_FLAG_TPM2) {
+ if (chip->flags & TPM_CHIP_FLAG_TPM2)
tpm2_shutdown(chip, TPM2_SU_STATE);
- return 0;
- }
-
- /* for buggy tpm, flush pcrs with extend to selected dummy */
- if (tpm_suspend_pcr)
- rc = tpm1_pcr_extend(chip, tpm_suspend_pcr, dummy_hash,
- "extending dummy pcr before suspend");
-
- /* now do the actual savestate */
- for (try = 0; try < TPM_RETRY; try++) {
- cmd.header.in = savestate_header;
- rc = tpm_transmit_cmd(chip, NULL, &cmd, SAVESTATE_RESULT_SIZE,
- 0, 0, NULL);
-
- /*
- * If the TPM indicates that it is too busy to respond to
- * this command then retry before giving up. It can take
- * several seconds for this TPM to be ready.
- *
- * This can happen if the TPM has already been sent the
- * SaveState command before the driver has loaded. TCG 1.2
- * specification states that any communication after SaveState
- * may cause the TPM to invalidate previously saved state.
- */
- if (rc != TPM_WARN_RETRY)
- break;
- tpm_msleep(TPM_TIMEOUT_RETRY);
- }
-
- if (rc)
- dev_err(&chip->dev,
- "Error (%d) sending savestate before suspend\n", rc);
- else if (try > 0)
- dev_warn(&chip->dev, "TPM savestate took %dms\n",
- try * TPM_TIMEOUT_RETRY);
+ else
+ rc = tpm1_pm_suspend(chip, tpm_suspend_pcr);
return rc;
}
diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
index f284a98a9455..754f7bcb15fa 100644
--- a/drivers/char/tpm/tpm.h
+++ b/drivers/char/tpm/tpm.h
@@ -542,6 +542,8 @@ ssize_t tpm_transmit_cmd(struct tpm_chip *chip, struct tpm_space *space,
const char *desc);
int tpm_startup(struct tpm_chip *chip);
int tpm_get_timeouts(struct tpm_chip *);
+
+int tpm1_pm_suspend(struct tpm_chip *chip, int tpm_suspend_pcr);
int tpm1_auto_startup(struct tpm_chip *chip);
int tpm1_do_selftest(struct tpm_chip *chip);
int tpm1_get_timeouts(struct tpm_chip *chip);
diff --git a/drivers/char/tpm/tpm1-cmd.c b/drivers/char/tpm/tpm1-cmd.c
index a69a02366c32..3bd9f1fa77ce 100644
--- a/drivers/char/tpm/tpm1-cmd.c
+++ b/drivers/char/tpm/tpm1-cmd.c
@@ -666,3 +666,64 @@ int tpm1_auto_startup(struct tpm_chip *chip)
rc = -ENODEV;
return rc;
}
+
+#define TPM_ORD_SAVESTATE 152
+#define SAVESTATE_RESULT_SIZE 10
+static const struct tpm_input_header savestate_header = {
+ .tag = cpu_to_be16(TPM_TAG_RQU_COMMAND),
+ .length = cpu_to_be32(10),
+ .ordinal = cpu_to_be32(TPM_ORD_SAVESTATE)
+};
+
+/**
+ * tpm1_pm_suspend() - pm suspend handler
+ * @chip: TPM chip to use.
+ * @tpm_suspend_pcr: flush pcr for buggy TPM chips.
+ *
+ * The functions saves the TPM state to be restored on resume.
+ *
+ * Return:
+ * * 0 on success,
+ * * < 0 on error.
+ */
+int tpm1_pm_suspend(struct tpm_chip *chip, int tpm_suspend_pcr)
+{
+ u8 dummy_hash[TPM_DIGEST_SIZE] = { 0 };
+ struct tpm_cmd_t cmd;
+ int rc, try;
+
+ /* for buggy tpm, flush pcrs with extend to selected dummy */
+ if (tpm_suspend_pcr)
+ rc = tpm1_pcr_extend(chip, tpm_suspend_pcr, dummy_hash,
+ "extending dummy pcr before suspend");
+
+ /* now do the actual savestate */
+ for (try = 0; try < TPM_RETRY; try++) {
+ cmd.header.in = savestate_header;
+ rc = tpm_transmit_cmd(chip, NULL, &cmd, SAVESTATE_RESULT_SIZE,
+ 0, 0, NULL);
+
+ /*
+ * If the TPM indicates that it is too busy to respond to
+ * this command then retry before giving up. It can take
+ * several seconds for this TPM to be ready.
+ *
+ * This can happen if the TPM has already been sent the
+ * SaveState command before the driver has loaded. TCG 1.2
+ * specification states that any communication after SaveState
+ * may cause the TPM to invalidate previously saved state.
+ */
+ if (rc != TPM_WARN_RETRY)
+ break;
+ tpm_msleep(TPM_TIMEOUT_RETRY);
+ }
+
+ if (rc)
+ dev_err(&chip->dev, "Error (%d) sending savestate before suspend\n",
+ rc);
+ else if (try > 0)
+ dev_warn(&chip->dev, "TPM savestate took %dms\n",
+ try * TPM_TIMEOUT_RETRY);
+
+ return rc;
+}
Tested-by: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx>
/Jarkko