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 4.19-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-4.19 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit e24f4a727929a2ded803e74680e8c426cbdf9851 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 c64481160b711..72fd2bbbe704e 100644 --- a/drivers/crypto/qat/qat_common/adf_pf2vf_msg.c +++ b/drivers/crypto/qat/qat_common/adf_pf2vf_msg.c @@ -195,6 +195,13 @@ 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;