crypto: qat - disregard spurious PFVF interrupts

Upon receiving a PFVF message, check if the interrupt bit is set in the
message. If it is not, that means that the interrupt was probably
triggered by a collision. In this case, disregard the message and
re-enable the interrupts.

Fixes: ed8ccaef ("crypto: qat - Add support for SRIOV")
Signed-off-by: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
Reviewed-by: Marco Chiappero <marco.chiappero@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/crypto/qat/qat_common/adf_pf2vf_msg.c

@@ -211,6 +211,11 @@ void adf_vf2pf_req_hndl(struct adf_accel_vf_info *vf_info)
 
 	/* Read message from the VF */
 	msg = ADF_CSR_RD(pmisc_addr, hw_data->get_pf2vf_offset(vf_nr));
+	if (!(msg & ADF_VF2PF_INT)) {
+		dev_info(&GET_DEV(accel_dev),
+			 "Spurious VF2PF interrupt, msg %X. Ignored\n", msg);
+		goto out;
+	}
 
 	/* To ACK, clear the VF2PFINT bit */
 	msg &= ~ADF_VF2PF_INT;
@@ -294,6 +299,7 @@ void adf_vf2pf_req_hndl(struct adf_accel_vf_info *vf_info)
 	if (resp && adf_iov_putmsg(accel_dev, resp, vf_nr))
 		dev_err(&GET_DEV(accel_dev), "Failed to send response to VF\n");
 
+out:
 	/* re-enable interrupt on PF from this VF */
 	adf_enable_vf2pf_interrupts(accel_dev, (1 << vf_nr));
 

drivers/crypto/qat/qat_common/adf_vf_isr.c

@@ -96,6 +96,11 @@ static void adf_pf2vf_bh_handler(void *data)
 
 	/* Read the message from PF */
 	msg = ADF_CSR_RD(pmisc_bar_addr, hw_data->get_pf2vf_offset(0));
+	if (!(msg & ADF_PF2VF_INT)) {
+		dev_info(&GET_DEV(accel_dev),
+			 "Spurious PF2VF interrupt, msg %X. Ignored\n", msg);
+		goto out;
+	}
 
 	if (!(msg & ADF_PF2VF_MSGORIGIN_SYSTEM))
 		/* Ignore legacy non-system (non-kernel) PF2VF messages */
@@ -144,6 +149,7 @@ static void adf_pf2vf_bh_handler(void *data)
 	msg &= ~ADF_PF2VF_INT;
 	ADF_CSR_WR(pmisc_bar_addr, hw_data->get_pf2vf_offset(0), msg);
 
+out:
 	/* Re-enable PF2VF interrupts */
 	adf_enable_pf2vf_interrupts(accel_dev);
 	return;