This is a note to let you know that I've just added the patch titled crypto: qat - detect PFVF collision after ACK to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: crypto-qat-detect-pfvf-collision-after-ack.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 3e2c71f864f1be9584ad13cc964d82414c665be6 Author: Giovanni Cabiddu <giovanni.cabiddu@xxxxxxxxx> Date: Tue Sep 28 12:44:29 2021 +0100 crypto: qat - detect PFVF collision after ACK [ Upstream commit 9b768e8a3909ac1ab39ed44a3933716da7761a6f ] Detect a PFVF collision between the local and the remote function by checking if the message on the PFVF CSR has been overwritten. This is done after the remote function confirms that the message has been received, by clearing the interrupt bit, or the maximum number of attempts (ADF_IOV_MSG_ACK_MAX_RETRY) to check the CSR has been exceeded. Fixes: ed8ccaef52fa ("crypto: qat - Add support for SRIOV") Signed-off-by: Giovanni Cabiddu <giovanni.cabiddu@xxxxxxxxx> Co-developed-by: Marco Chiappero <marco.chiappero@xxxxxxxxx> Signed-off-by: Marco Chiappero <marco.chiappero@xxxxxxxxx> Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/crypto/qat/qat_common/adf_pf2vf_msg.c b/drivers/crypto/qat/qat_common/adf_pf2vf_msg.c index 711706819b05d..7e45c21a61657 100644 --- a/drivers/crypto/qat/qat_common/adf_pf2vf_msg.c +++ b/drivers/crypto/qat/qat_common/adf_pf2vf_msg.c @@ -218,6 +218,13 @@ static int __adf_iov_putmsg(struct adf_accel_dev *accel_dev, u32 msg, u8 vf_nr) val = ADF_CSR_RD(pmisc_bar_addr, pf2vf_offset); } while ((val & int_bit) && (count++ < ADF_IOV_MSG_ACK_MAX_RETRY)); + if (val != msg) { + dev_dbg(&GET_DEV(accel_dev), + "Collision - PFVF CSR overwritten by remote function\n"); + ret = -EIO; + goto out; + } + if (val & int_bit) { dev_dbg(&GET_DEV(accel_dev), "ACK not received from remote\n"); val &= ~int_bit;