From: Niklas Schnelle <schnelle@linux.ibm.com>
Date: Wed, 24 Mar 2021 10:21:21 +0000 (+0100)
Subject: s390/pci: fix DMA cleanup on hard deconfigure
X-Git-Tag: accepted/tizen/unified/20230118.172025~7373^2~39
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=652d40b2f8bec14957295f999e3d329c3b53390f;p=platform%2Fkernel%2Flinux-rpi.git

s390/pci: fix DMA cleanup on hard deconfigure

In commit dee60c0dbc83 ("s390/pci: add zpci_event_hard_deconfigured()")
we added a zdev_enabled() check to what was previously an uncoditional
call to zpci_disable_device(). There are two problems with that. Firstly
zpci_had_deconfigured() is only called on event 0x0304 for which the
device is always already disabled by the platform so it is always false.
Secondly zpci_disable_device() not only disables the device but also
calls zpci_dma_exit_device() which is thus not called and we leak the
DMA tables.

Fix this by calling zpci_disable_device() unconditionally to perform
Linux side cleanup including the freeing of DMA tables.

Fixes: dee60c0dbc83 ("s390/pci: add zpci_event_hard_deconfigured()")
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Acked-by: Pierre Morel <pmorel@linux.ibm.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
---

diff --git a/arch/s390/pci/pci_event.c b/arch/s390/pci/pci_event.c
index 9455c5b..ae3054d 100644
--- a/arch/s390/pci/pci_event.c
+++ b/arch/s390/pci/pci_event.c
@@ -12,6 +12,7 @@
 #include <linux/kernel.h>
 #include <linux/pci.h>
 #include <asm/pci_debug.h>
+#include <asm/pci_dma.h>
 #include <asm/sclp.h>
 
 #include "pci_bus.h"
@@ -76,18 +77,16 @@ void zpci_event_error(void *data)
 static void zpci_event_hard_deconfigured(struct zpci_dev *zdev, u32 fh)
 {
 	enum zpci_state state;
-	int rc;
 
 	zdev->fh = fh;
 	/* Give the driver a hint that the function is
 	 * already unusable.
 	 */
 	zpci_bus_remove_device(zdev, true);
-	if (zdev_enabled(zdev)) {
-		rc = zpci_disable_device(zdev);
-		if (rc)
-			return;
-	}
+	/* Even though the device is already gone we still
+	 * need to free zPCI resources as part of the disable.
+	 */
+	zpci_disable_device(zdev);
 	zdev->state = ZPCI_FN_STATE_STANDBY;
 	if (!clp_get_state(zdev->fid, &state) &&
 	    state == ZPCI_FN_STATE_RESERVED) {