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From:   Giovanni Cabiddu <giovanni.cabiddu@intel.com>
To:     herbert@gondor.apana.org.au
Cc:     linux-crypto@vger.kernel.org, qat-linux@intel.com,
        Giovanni Cabiddu <giovanni.cabiddu@intel.com>,
        Marco Chiappero <marco.chiappero@intel.com>
Subject: [PATCH 01/12] crypto: qat - detect PFVF collision after ACK
Date:   Tue, 28 Sep 2021 12:44:29 +0100
Message-Id: <20210928114440.355368-2-giovanni.cabiddu@intel.com>
In-Reply-To: <20210928114440.355368-1-giovanni.cabiddu@intel.com>
References: <20210928114440.355368-1-giovanni.cabiddu@intel.com>
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Organization: Intel Research and Development Ireland Ltd - Co. Reg. #308263 - Collinstown Industrial Park, Leixlip, County Kildare - Ireland
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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@intel.com>
Co-developed-by: Marco Chiappero <marco.chiappero@intel.com>
Signed-off-by: Marco Chiappero <marco.chiappero@intel.com>
---
 drivers/crypto/qat/qat_common/adf_pf2vf_msg.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/crypto/qat/qat_common/adf_pf2vf_msg.c b/drivers/crypto/qat/qat_common/adf_pf2vf_msg.c
index 976b9ab7617c..789a4135e28c 100644
--- a/drivers/crypto/qat/qat_common/adf_pf2vf_msg.c
+++ b/drivers/crypto/qat/qat_common/adf_pf2vf_msg.c
@@ -156,6 +156,13 @@ 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;
-- 
2.31.1