tpm: ibmvtpm: retry on H_CLOSED in tpm_ibmvtpm_send()

commit eba5cf3dcb844c82f54d4a857e124824e252206d upstream.

tpm_ibmvtpm_send() can fail during PowerVM Live Partition Mobility resume
with an H_CLOSED return from ibmvtpm_send_crq().  The PAPR says, 'The
"partner partition suspended" transport event disables the associated CRQ
such that any H_SEND_CRQ hcall() to the associated CRQ returns H_Closed
until the CRQ has been explicitly enabled using the H_ENABLE_CRQ hcall.'
This patch adds a check in tpm_ibmvtpm_send() for an H_CLOSED return from
ibmvtpm_send_crq() and in that case calls tpm_ibmvtpm_resume() and
retries the ibmvtpm_send_crq() once.

Cc: stable@vger.kernel.org # 3.7.x
Fixes: 132f76294744 ("drivers/char/tpm: Add new device driver to support IBM vTPM")
Reported-by: Linh Pham <phaml@us.ibm.com>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Signed-off-by: George Wilson <gcwilson@linux.ibm.com>
Tested-by: Linh Pham <phaml@us.ibm.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/char/tpm/tpm_ibmvtpm.c b/drivers/char/tpm/tpm_ibmvtpm.c
index 78cc526..e82013d 100644 (file)
--- a/drivers/char/tpm/tpm_ibmvtpm.c
+++ b/drivers/char/tpm/tpm_ibmvtpm.c
@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0-only
 /*
- * Copyright (C) 2012 IBM Corporation
+ * Copyright (C) 2012-2020 IBM Corporation
  *
  * Author: Ashley Lai <ashleydlai@gmail.com>
  *
@@ -134,6 +134,64 @@ static int tpm_ibmvtpm_recv(struct tpm_chip *chip, u8 *buf, size_t count)
 }
 
 /**
+ * ibmvtpm_crq_send_init - Send a CRQ initialize message
+ * @ibmvtpm:   vtpm device struct
+ *
+ * Return:
+ *     0 on success.
+ *     Non-zero on failure.
+ */
+static int ibmvtpm_crq_send_init(struct ibmvtpm_dev *ibmvtpm)
+{
+       int rc;
+
+       rc = ibmvtpm_send_crq_word(ibmvtpm->vdev, INIT_CRQ_CMD);
+       if (rc != H_SUCCESS)
+               dev_err(ibmvtpm->dev,
+                       "%s failed rc=%d\n", __func__, rc);
+
+       return rc;
+}
+
+/**
+ * tpm_ibmvtpm_resume - Resume from suspend
+ *
+ * @dev:       device struct
+ *
+ * Return: Always 0.
+ */
+static int tpm_ibmvtpm_resume(struct device *dev)
+{
+       struct tpm_chip *chip = dev_get_drvdata(dev);
+       struct ibmvtpm_dev *ibmvtpm = dev_get_drvdata(&chip->dev);
+       int rc = 0;
+
+       do {
+               if (rc)
+                       msleep(100);
+               rc = plpar_hcall_norets(H_ENABLE_CRQ,
+                                       ibmvtpm->vdev->unit_address);
+       } while (rc == H_IN_PROGRESS || rc == H_BUSY || H_IS_LONG_BUSY(rc));
+
+       if (rc) {
+               dev_err(dev, "Error enabling ibmvtpm rc=%d\n", rc);
+               return rc;
+       }
+
+       rc = vio_enable_interrupts(ibmvtpm->vdev);
+       if (rc) {
+               dev_err(dev, "Error vio_enable_interrupts rc=%d\n", rc);
+               return rc;
+       }
+
+       rc = ibmvtpm_crq_send_init(ibmvtpm);
+       if (rc)
+               dev_err(dev, "Error send_init rc=%d\n", rc);
+
+       return rc;
+}
+
+/**
  * tpm_ibmvtpm_send() - Send a TPM command
  * @chip:      tpm chip struct
  * @buf:       buffer contains data to send
@@ -146,6 +204,7 @@ static int tpm_ibmvtpm_recv(struct tpm_chip *chip, u8 *buf, size_t count)
 static int tpm_ibmvtpm_send(struct tpm_chip *chip, u8 *buf, size_t count)
 {
        struct ibmvtpm_dev *ibmvtpm = dev_get_drvdata(&chip->dev);
+       bool retry = true;
        int rc, sig;
 
        if (!ibmvtpm->rtce_buf) {
@@ -179,18 +238,27 @@ static int tpm_ibmvtpm_send(struct tpm_chip *chip, u8 *buf, size_t count)
         */
        ibmvtpm->tpm_processing_cmd = true;
 
+again:
        rc = ibmvtpm_send_crq(ibmvtpm->vdev,
                        IBMVTPM_VALID_CMD, VTPM_TPM_COMMAND,
                        count, ibmvtpm->rtce_dma_handle);
        if (rc != H_SUCCESS) {
+               /*
+                * H_CLOSED can be returned after LPM resume.  Call
+                * tpm_ibmvtpm_resume() to re-enable the CRQ then retry
+                * ibmvtpm_send_crq() once before failing.
+                */
+               if (rc == H_CLOSED && retry) {
+                       tpm_ibmvtpm_resume(ibmvtpm->dev);
+                       retry = false;
+                       goto again;
+               }
                dev_err(ibmvtpm->dev, "tpm_ibmvtpm_send failed rc=%d\n", rc);
-               rc = 0;
                ibmvtpm->tpm_processing_cmd = false;
-       } else
-               rc = 0;
+       }
 
        spin_unlock(&ibmvtpm->rtce_lock);
-       return rc;
+       return 0;
 }
 
 static void tpm_ibmvtpm_cancel(struct tpm_chip *chip)
@@ -269,26 +337,6 @@ static int ibmvtpm_crq_send_init_complete(struct ibmvtpm_dev *ibmvtpm)
 }
 
 /**
- * ibmvtpm_crq_send_init - Send a CRQ initialize message
- * @ibmvtpm:   vtpm device struct
- *
- * Return:
- *     0 on success.
- *     Non-zero on failure.
- */
-static int ibmvtpm_crq_send_init(struct ibmvtpm_dev *ibmvtpm)
-{
-       int rc;
-
-       rc = ibmvtpm_send_crq_word(ibmvtpm->vdev, INIT_CRQ_CMD);
-       if (rc != H_SUCCESS)
-               dev_err(ibmvtpm->dev,
-                       "ibmvtpm_crq_send_init failed rc=%d\n", rc);
-
-       return rc;
-}
-
-/**
  * tpm_ibmvtpm_remove - ibm vtpm remove entry point
  * @vdev:      vio device struct
  *
@@ -400,44 +448,6 @@ static int ibmvtpm_reset_crq(struct ibmvtpm_dev *ibmvtpm)
                                  ibmvtpm->crq_dma_handle, CRQ_RES_BUF_SIZE);
 }
 
-/**
- * tpm_ibmvtpm_resume - Resume from suspend
- *
- * @dev:       device struct
- *
- * Return: Always 0.
- */
-static int tpm_ibmvtpm_resume(struct device *dev)
-{
-       struct tpm_chip *chip = dev_get_drvdata(dev);
-       struct ibmvtpm_dev *ibmvtpm = dev_get_drvdata(&chip->dev);
-       int rc = 0;
-
-       do {
-               if (rc)
-                       msleep(100);
-               rc = plpar_hcall_norets(H_ENABLE_CRQ,
-                                       ibmvtpm->vdev->unit_address);
-       } while (rc == H_IN_PROGRESS || rc == H_BUSY || H_IS_LONG_BUSY(rc));
-
-       if (rc) {
-               dev_err(dev, "Error enabling ibmvtpm rc=%d\n", rc);
-               return rc;
-       }
-
-       rc = vio_enable_interrupts(ibmvtpm->vdev);
-       if (rc) {
-               dev_err(dev, "Error vio_enable_interrupts rc=%d\n", rc);
-               return rc;
-       }
-
-       rc = ibmvtpm_crq_send_init(ibmvtpm);
-       if (rc)
-               dev_err(dev, "Error send_init rc=%d\n", rc);
-
-       return rc;
-}
-
 static bool tpm_ibmvtpm_req_canceled(struct tpm_chip *chip, u8 status)
 {
        return (status == 0);