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@intel.com>
Co-developed-by: Marco Chiappero <marco.chiappero@intel.com>
Signed-off-by: Marco Chiappero <marco.chiappero@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/crypto/qat/qat_common/adf_pf2vf_msg.c b/drivers/crypto/qat/qat_common/adf_pf2vf_msg.c
index c64481160b7118e305153ac35e87a7db23a96504..72fd2bbbe704ef00dcc44a19c48087edc4634433 100644 (file)
--- 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;