From 18fcba469ba5359c1de7e3fb16f7b9e8cd1b8e02 Mon Sep 17 00:00:00 2001
From: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
Date: Tue, 28 Sep 2021 12:44:30 +0100
Subject: [PATCH] crypto: qat - disregard spurious PFVF interrupts
Git-commit: 18fcba469ba5359c1de7e3fb16f7b9e8cd1b8e02
References: git-fixes
Patch-mainline: v5.16-rc1

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: ed8ccaef52fa ("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>
Signed-off-by: Oliver Neukum <oneukum@suse.com>
---
 drivers/crypto/qat/qat_common/adf_pf2vf_msg.c |    6 ++++++
 drivers/crypto/qat/qat_common/adf_vf_isr.c    |    6 ++++++
 2 files changed, 12 insertions(+)

--- a/drivers/crypto/qat/qat_common/adf_pf2vf_msg.c
+++ b/drivers/crypto/qat/qat_common/adf_pf2vf_msg.c
@@ -251,6 +251,11 @@ void adf_vf2pf_req_hndl(struct adf_accel
 
 	/* 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;
@@ -334,6 +339,7 @@ void adf_vf2pf_req_hndl(struct adf_accel
 	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));
 	return;
--- a/drivers/crypto/qat/qat_common/adf_vf_isr.c
+++ b/drivers/crypto/qat/qat_common/adf_vf_isr.c
@@ -123,6 +123,11 @@ static void adf_pf2vf_bh_handler(void *d
 
 	/* 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 */
@@ -171,6 +176,7 @@ static void adf_pf2vf_bh_handler(void *d
 	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;