[PATCH 4/4] s390/pci: Use lock guard for pci_rescan_remove_lock
From: Benjamin Block
Date: Fri Mar 06 2026 - 11:56:38 EST
There are quite a few places in the s390 architecture code for the PCI
subsystem where the kernel needs to lock `pci_rescan_remove_lock` now;
which is done by calling pci_lock_rescan_remove() to lock, and
pci_unlock_rescan_remove() to unlock the mutex.
Instead of always manually calling both functions, which induces a
certain amount of visual clutter, and in some cases of errors, cleanup,
and jumplabels more complexity, use either guard() or scoped_guard()
depending on the context.
Convert all users in the s390 architecture code for PCI.
Signed-off-by: Benjamin Block <bblock@xxxxxxxxxxxxx>
---
arch/s390/pci/pci.c | 8 +++----
arch/s390/pci/pci_bus.c | 3 +--
arch/s390/pci/pci_event.c | 45 +++++++++++++++++----------------------
arch/s390/pci/pci_iov.c | 3 +--
arch/s390/pci/pci_sysfs.c | 9 +++-----
5 files changed, 27 insertions(+), 41 deletions(-)
diff --git a/arch/s390/pci/pci.c b/arch/s390/pci/pci.c
index fd16e6ad21c1..86ef1e516857 100644
--- a/arch/s390/pci/pci.c
+++ b/arch/s390/pci/pci.c
@@ -632,10 +632,9 @@ void pcibios_release_device(struct pci_dev *pdev)
{
struct zpci_dev *zdev = to_zpci(pdev);
- pci_lock_rescan_remove();
+ guard(pci_rescan_remove)();
zpci_unmap_resources(pdev);
zpci_zdev_put(zdev);
- pci_unlock_rescan_remove();
}
int pcibios_enable_device(struct pci_dev *pdev, int mask)
@@ -1213,9 +1212,8 @@ static int __init pci_base_init(void)
if (rc)
goto out_irq;
- pci_lock_rescan_remove();
- rc = zpci_scan_devices();
- pci_unlock_rescan_remove();
+ scoped_guard(pci_rescan_remove)
+ rc = zpci_scan_devices();
if (rc)
goto out_find;
diff --git a/arch/s390/pci/pci_bus.c b/arch/s390/pci/pci_bus.c
index 2b598222c621..c1b48b572e86 100644
--- a/arch/s390/pci/pci_bus.c
+++ b/arch/s390/pci/pci_bus.c
@@ -82,9 +82,8 @@ int zpci_bus_scan_device(struct zpci_dev *zdev)
if (!pdev)
return -ENODEV;
- pci_lock_rescan_remove();
+ guard(pci_rescan_remove)();
pci_bus_add_device(pdev);
- pci_unlock_rescan_remove();
return 0;
}
diff --git a/arch/s390/pci/pci_event.c b/arch/s390/pci/pci_event.c
index edfaeed737ac..98253706b591 100644
--- a/arch/s390/pci/pci_event.c
+++ b/arch/s390/pci/pci_event.c
@@ -342,9 +342,8 @@ static void __zpci_event_error(struct zpci_ccdf_err *ccdf)
no_pdev:
if (zdev)
mutex_unlock(&zdev->state_lock);
- pci_lock_rescan_remove();
+ guard(pci_rescan_remove)();
zpci_zdev_put(zdev);
- pci_unlock_rescan_remove();
}
void zpci_event_error(void *data)
@@ -389,7 +388,6 @@ static void __zpci_event_availability(struct zpci_ccdf_avail *ccdf)
struct zpci_dev *zdev = get_zdev_by_fid(ccdf->fid);
bool existing_zdev = !!zdev;
enum zpci_state state;
- int rc;
zpci_dbg(3, "avl fid:%x, fh:%x, pec:%x\n",
ccdf->fid, ccdf->fh, ccdf->pec);
@@ -403,12 +401,11 @@ static void __zpci_event_availability(struct zpci_ccdf_avail *ccdf)
zdev = zpci_create_device(ccdf->fid, ccdf->fh, ZPCI_FN_STATE_CONFIGURED);
if (IS_ERR(zdev))
break;
- pci_lock_rescan_remove();
- rc = zpci_add_device(zdev);
- pci_unlock_rescan_remove();
- if (rc) {
- kfree(zdev);
- break;
+ scoped_guard(pci_rescan_remove) {
+ if (zpci_add_device(zdev)) {
+ kfree(zdev);
+ break;
+ }
}
} else {
if (zdev->state == ZPCI_FN_STATE_RESERVED)
@@ -425,12 +422,11 @@ static void __zpci_event_availability(struct zpci_ccdf_avail *ccdf)
zdev = zpci_create_device(ccdf->fid, ccdf->fh, ZPCI_FN_STATE_STANDBY);
if (IS_ERR(zdev))
break;
- pci_lock_rescan_remove();
- rc = zpci_add_device(zdev);
- pci_unlock_rescan_remove();
- if (rc) {
- kfree(zdev);
- break;
+ scoped_guard(pci_rescan_remove) {
+ if (zpci_add_device(zdev)) {
+ kfree(zdev);
+ break;
+ }
}
} else {
if (zdev->state == ZPCI_FN_STATE_RESERVED)
@@ -459,33 +455,30 @@ static void __zpci_event_availability(struct zpci_ccdf_avail *ccdf)
/* The 0x0304 event may immediately reserve the device */
if (!clp_get_state(zdev->fid, &state) &&
state == ZPCI_FN_STATE_RESERVED) {
- pci_lock_rescan_remove();
+ guard(pci_rescan_remove)();
zpci_device_reserved(zdev);
- pci_unlock_rescan_remove();
}
}
break;
case 0x0306: /* 0x308 or 0x302 for multiple devices */
- pci_lock_rescan_remove();
- zpci_remove_reserved_devices();
- zpci_scan_devices();
- pci_unlock_rescan_remove();
+ scoped_guard(pci_rescan_remove) {
+ zpci_remove_reserved_devices();
+ zpci_scan_devices();
+ }
break;
case 0x0308: /* Standby -> Reserved */
if (!zdev)
break;
- pci_lock_rescan_remove();
- zpci_device_reserved(zdev);
- pci_unlock_rescan_remove();
+ scoped_guard(pci_rescan_remove)
+ zpci_device_reserved(zdev);
break;
default:
break;
}
if (existing_zdev) {
mutex_unlock(&zdev->state_lock);
- pci_lock_rescan_remove();
+ guard(pci_rescan_remove)();
zpci_zdev_put(zdev);
- pci_unlock_rescan_remove();
}
}
diff --git a/arch/s390/pci/pci_iov.c b/arch/s390/pci/pci_iov.c
index 13050ce5c3e9..1f7e4dd018e7 100644
--- a/arch/s390/pci/pci_iov.c
+++ b/arch/s390/pci/pci_iov.c
@@ -38,10 +38,9 @@ void zpci_iov_map_resources(struct pci_dev *pdev)
void zpci_iov_remove_virtfn(struct pci_dev *pdev, int vfn)
{
- pci_lock_rescan_remove();
+ guard(pci_rescan_remove)();
/* Linux' vfid's start at 0 vfn at 1 */
pci_iov_remove_virtfn(pdev->physfn, vfn - 1);
- pci_unlock_rescan_remove();
}
static int zpci_iov_link_virtfn(struct pci_dev *pdev, struct pci_dev *virtfn, int vfid)
diff --git a/arch/s390/pci/pci_sysfs.c b/arch/s390/pci/pci_sysfs.c
index c2444a23e26c..f5027aa95928 100644
--- a/arch/s390/pci/pci_sysfs.c
+++ b/arch/s390/pci/pci_sysfs.c
@@ -98,9 +98,9 @@ static ssize_t recover_store(struct device *dev, struct device_attribute *attr,
WARN_ON_ONCE(!kn);
/* Device needs to be configured and state must not change */
- mutex_lock(&zdev->state_lock);
+ guard(mutex)(&zdev->state_lock);
if (zdev->state != ZPCI_FN_STATE_CONFIGURED)
- goto out;
+ return count;
/* device_remove_file() serializes concurrent calls ignoring all but
* the first
@@ -112,15 +112,12 @@ static ssize_t recover_store(struct device *dev, struct device_attribute *attr,
* Once it unblocks from pci_lock_rescan_remove() the original pdev
* will already be removed.
*/
- pci_lock_rescan_remove();
+ guard(pci_rescan_remove)();
if (pci_dev_is_added(pdev)) {
ret = _do_recover(pdev, zdev);
}
pci_rescan_bus(zdev->zbus->bus);
- pci_unlock_rescan_remove();
-out:
- mutex_unlock(&zdev->state_lock);
if (kn)
sysfs_unbreak_active_protection(kn);
return ret ? ret : count;
--
2.53.0