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-rw-r--r--arch/s390/pci/pci.c45
-rw-r--r--arch/s390/pci/pci_bus.h7
-rw-r--r--arch/s390/pci/pci_event.c22
-rw-r--r--arch/s390/pci/pci_mmio.c12
4 files changed, 62 insertions, 24 deletions
diff --git a/arch/s390/pci/pci.c b/arch/s390/pci/pci.c
index 5bbdc4190b8b..cd6676c2d602 100644
--- a/arch/s390/pci/pci.c
+++ b/arch/s390/pci/pci.c
@@ -45,6 +45,7 @@
/* list of all detected zpci devices */
static LIST_HEAD(zpci_list);
static DEFINE_SPINLOCK(zpci_list_lock);
+static DEFINE_MUTEX(zpci_add_remove_lock);
static DECLARE_BITMAP(zpci_domain, ZPCI_DOMAIN_BITMAP_SIZE);
static DEFINE_SPINLOCK(zpci_domain_lock);
@@ -70,6 +71,15 @@ EXPORT_SYMBOL_GPL(zpci_aipb);
struct airq_iv *zpci_aif_sbv;
EXPORT_SYMBOL_GPL(zpci_aif_sbv);
+void zpci_zdev_put(struct zpci_dev *zdev)
+{
+ if (!zdev)
+ return;
+ mutex_lock(&zpci_add_remove_lock);
+ kref_put_lock(&zdev->kref, zpci_release_device, &zpci_list_lock);
+ mutex_unlock(&zpci_add_remove_lock);
+}
+
struct zpci_dev *get_zdev_by_fid(u32 fid)
{
struct zpci_dev *tmp, *zdev = NULL;
@@ -837,6 +847,7 @@ int zpci_add_device(struct zpci_dev *zdev)
{
int rc;
+ mutex_lock(&zpci_add_remove_lock);
zpci_dbg(1, "add fid:%x, fh:%x, c:%d\n", zdev->fid, zdev->fh, zdev->state);
rc = zpci_init_iommu(zdev);
if (rc)
@@ -850,12 +861,14 @@ int zpci_add_device(struct zpci_dev *zdev)
spin_lock(&zpci_list_lock);
list_add_tail(&zdev->entry, &zpci_list);
spin_unlock(&zpci_list_lock);
+ mutex_unlock(&zpci_add_remove_lock);
return 0;
error_destroy_iommu:
zpci_destroy_iommu(zdev);
error:
zpci_dbg(0, "add fid:%x, rc:%d\n", zdev->fid, rc);
+ mutex_unlock(&zpci_add_remove_lock);
return rc;
}
@@ -925,21 +938,20 @@ int zpci_deconfigure_device(struct zpci_dev *zdev)
* @zdev: the zpci_dev that was reserved
*
* Handle the case that a given zPCI function was reserved by another system.
- * After a call to this function the zpci_dev can not be found via
- * get_zdev_by_fid() anymore but may still be accessible via existing
- * references though it will not be functional anymore.
*/
void zpci_device_reserved(struct zpci_dev *zdev)
{
- /*
- * Remove device from zpci_list as it is going away. This also
- * makes sure we ignore subsequent zPCI events for this device.
- */
- spin_lock(&zpci_list_lock);
- list_del(&zdev->entry);
- spin_unlock(&zpci_list_lock);
+ lockdep_assert_held(&zdev->state_lock);
+ /* We may declare the device reserved multiple times */
+ if (zdev->state == ZPCI_FN_STATE_RESERVED)
+ return;
zdev->state = ZPCI_FN_STATE_RESERVED;
zpci_dbg(3, "rsv fid:%x\n", zdev->fid);
+ /*
+ * The underlying device is gone. Allow the zdev to be freed
+ * as soon as all other references are gone by accounting for
+ * the removal as a dropped reference.
+ */
zpci_zdev_put(zdev);
}
@@ -947,13 +959,14 @@ void zpci_release_device(struct kref *kref)
{
struct zpci_dev *zdev = container_of(kref, struct zpci_dev, kref);
+ lockdep_assert_held(&zpci_add_remove_lock);
WARN_ON(zdev->state != ZPCI_FN_STATE_RESERVED);
-
- if (zdev->zbus->bus)
- zpci_bus_remove_device(zdev, false);
-
- if (zdev_enabled(zdev))
- zpci_disable_device(zdev);
+ /*
+ * We already hold zpci_list_lock thanks to kref_put_lock().
+ * This makes sure no new reference can be taken from the list.
+ */
+ list_del(&zdev->entry);
+ spin_unlock(&zpci_list_lock);
if (zdev->has_hp_slot)
zpci_exit_slot(zdev);
diff --git a/arch/s390/pci/pci_bus.h b/arch/s390/pci/pci_bus.h
index e86a9419d233..ae3d7a9159bd 100644
--- a/arch/s390/pci/pci_bus.h
+++ b/arch/s390/pci/pci_bus.h
@@ -21,11 +21,8 @@ int zpci_bus_scan_device(struct zpci_dev *zdev);
void zpci_bus_remove_device(struct zpci_dev *zdev, bool set_error);
void zpci_release_device(struct kref *kref);
-static inline void zpci_zdev_put(struct zpci_dev *zdev)
-{
- if (zdev)
- kref_put(&zdev->kref, zpci_release_device);
-}
+
+void zpci_zdev_put(struct zpci_dev *zdev);
static inline void zpci_zdev_get(struct zpci_dev *zdev)
{
diff --git a/arch/s390/pci/pci_event.c b/arch/s390/pci/pci_event.c
index 7bd7721c1239..2fbee3887d13 100644
--- a/arch/s390/pci/pci_event.c
+++ b/arch/s390/pci/pci_event.c
@@ -335,6 +335,22 @@ static void zpci_event_hard_deconfigured(struct zpci_dev *zdev, u32 fh)
zdev->state = ZPCI_FN_STATE_STANDBY;
}
+static void zpci_event_reappear(struct zpci_dev *zdev)
+{
+ lockdep_assert_held(&zdev->state_lock);
+ /*
+ * The zdev is in the reserved state. This means that it was presumed to
+ * go away but there are still undropped references. Now, the platform
+ * announced its availability again. Bring back the lingering zdev
+ * to standby. This is safe because we hold a temporary reference
+ * now so that it won't go away. Account for the re-appearance of the
+ * underlying device by incrementing the reference count.
+ */
+ zdev->state = ZPCI_FN_STATE_STANDBY;
+ zpci_zdev_get(zdev);
+ zpci_dbg(1, "rea fid:%x, fh:%x\n", zdev->fid, zdev->fh);
+}
+
static void __zpci_event_availability(struct zpci_ccdf_avail *ccdf)
{
struct zpci_dev *zdev = get_zdev_by_fid(ccdf->fid);
@@ -358,8 +374,10 @@ static void __zpci_event_availability(struct zpci_ccdf_avail *ccdf)
break;
}
} else {
+ if (zdev->state == ZPCI_FN_STATE_RESERVED)
+ zpci_event_reappear(zdev);
/* the configuration request may be stale */
- if (zdev->state != ZPCI_FN_STATE_STANDBY)
+ else if (zdev->state != ZPCI_FN_STATE_STANDBY)
break;
zdev->state = ZPCI_FN_STATE_CONFIGURED;
}
@@ -375,6 +393,8 @@ static void __zpci_event_availability(struct zpci_ccdf_avail *ccdf)
break;
}
} else {
+ if (zdev->state == ZPCI_FN_STATE_RESERVED)
+ zpci_event_reappear(zdev);
zpci_update_fh(zdev, ccdf->fh);
}
break;
diff --git a/arch/s390/pci/pci_mmio.c b/arch/s390/pci/pci_mmio.c
index 5fcc1a3b04bd..51e7a28af899 100644
--- a/arch/s390/pci/pci_mmio.c
+++ b/arch/s390/pci/pci_mmio.c
@@ -32,8 +32,10 @@ static inline int __pcistb_mio_inuser(
u64 len, u8 *status)
{
int cc, exception;
+ bool sacf_flag;
exception = 1;
+ sacf_flag = enable_sacf_uaccess();
asm_inline volatile (
" sacf 256\n"
"0: .insn rsy,0xeb00000000d4,%[len],%[ioaddr],%[src]\n"
@@ -44,6 +46,7 @@ static inline int __pcistb_mio_inuser(
: CC_OUT(cc, cc), [len] "+d" (len), [exc] "+d" (exception)
: [ioaddr] "a" (ioaddr), [src] "Q" (*((u8 __force *)src))
: CC_CLOBBER_LIST("memory"));
+ disable_sacf_uaccess(sacf_flag);
*status = len >> 24 & 0xff;
return exception ? -ENXIO : CC_TRANSFORM(cc);
}
@@ -54,6 +57,7 @@ static inline int __pcistg_mio_inuser(
{
union register_pair ioaddr_len = {.even = (u64 __force)ioaddr, .odd = ulen};
int cc, exception;
+ bool sacf_flag;
u64 val = 0;
u64 cnt = ulen;
u8 tmp;
@@ -64,6 +68,7 @@ static inline int __pcistg_mio_inuser(
* address space. pcistg then uses the user mappings.
*/
exception = 1;
+ sacf_flag = enable_sacf_uaccess();
asm_inline volatile (
" sacf 256\n"
"0: llgc %[tmp],0(%[src])\n"
@@ -81,6 +86,7 @@ static inline int __pcistg_mio_inuser(
CC_OUT(cc, cc), [ioaddr_len] "+&d" (ioaddr_len.pair)
:
: CC_CLOBBER_LIST("memory"));
+ disable_sacf_uaccess(sacf_flag);
*status = ioaddr_len.odd >> 24 & 0xff;
cc = exception ? -ENXIO : CC_TRANSFORM(cc);
@@ -204,6 +210,7 @@ static inline int __pcilg_mio_inuser(
u64 ulen, u8 *status)
{
union register_pair ioaddr_len = {.even = (u64 __force)ioaddr, .odd = ulen};
+ bool sacf_flag;
u64 cnt = ulen;
int shift = ulen * 8;
int cc, exception;
@@ -215,6 +222,7 @@ static inline int __pcilg_mio_inuser(
* user address @dst
*/
exception = 1;
+ sacf_flag = enable_sacf_uaccess();
asm_inline volatile (
" sacf 256\n"
"0: .insn rre,0xb9d60000,%[val],%[ioaddr_len]\n"
@@ -236,10 +244,10 @@ static inline int __pcilg_mio_inuser(
: [ioaddr_len] "+&d" (ioaddr_len.pair), [exc] "+d" (exception),
CC_OUT(cc, cc), [val] "=d" (val),
[dst] "+a" (dst), [cnt] "+d" (cnt), [tmp] "=d" (tmp),
- [shift] "+d" (shift)
+ [shift] "+a" (shift)
:
: CC_CLOBBER_LIST("memory"));
-
+ disable_sacf_uaccess(sacf_flag);
cc = exception ? -ENXIO : CC_TRANSFORM(cc);
/* did we write everything to the user space buffer? */
if (!cc && cnt != 0)
generated by cgit (git 2.34.1) at 2025-05-30 19:04:18 +0000