lkml.org 
[lkml]   [2020]   [Mar]   [18]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v3] tpm: ibmvtpm: retry on H_CLOSED in tpm_ibmvtpm_send()
Date
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.

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>
Fixes: 132f76294744 ("Add new device driver to support IBM vTPM")
---
drivers/char/tpm/tpm_ibmvtpm.c | 136 ++++++++++++++++++---------------
1 file changed, 73 insertions(+), 63 deletions(-)

diff --git a/drivers/char/tpm/tpm_ibmvtpm.c b/drivers/char/tpm/tpm_ibmvtpm.c
index 78cc52690177..d097d47e0efa 100644
--- 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>
*
@@ -133,6 +133,64 @@ static int tpm_ibmvtpm_recv(struct tpm_chip *chip, u8 *buf, size_t count)
return len;
}

+/**
+ * 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_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
@@ -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)
@@ -268,26 +336,6 @@ static int ibmvtpm_crq_send_init_complete(struct ibmvtpm_dev *ibmvtpm)
return rc;
}

-/**
- * 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);
--
2.24.1
\
 
 \ /
  Last update: 2020-03-19 00:50    [W:0.050 / U:6.780 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site