Merge tag 's390-5.20-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

Pull s390 updates from Alexander Gordeev:

 - Rework copy_oldmem_page() callback to take an iov_iter.

   This includes a few prerequisite updates and fixes to the oldmem
   reading code.

 - Rework cpufeature implementation to allow for various CPU feature
   indications, which is not only limited to hardware capabilities, but
   also allows CPU facilities.

 - Use the cpufeature rework to autoload Ultravisor module when CPU
   facility 158 is available.

 - Add ELF note type for encrypted CPU state of a protected virtual CPU.
   The zgetdump tool from s390-tools package will decrypt the CPU state
   using a Customer Communication Key and overwrite respective notes to
   make the data accessible for crash and other debugging tools.

 - Use vzalloc() instead of vmalloc() + memset() in ChaCha20 crypto
   test.

 - Fix incorrect recovery of kretprobe modified return address in
   stacktrace.

 - Switch the NMI handler to use generic irqentry_nmi_enter() and
   irqentry_nmi_exit() helper functions.

 - Rework the cryptographic Adjunct Processors (AP) pass-through design
   to support dynamic changes to the AP matrix of a running guest as
   well as to implement more of the AP architecture.

 - Minor boot code cleanups.

 - Grammar and typo fixes to hmcdrv and tape drivers.

* tag 's390-5.20-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (46 commits)
  Revert "s390/smp: enforce lowcore protection on CPU restart"
  Revert "s390/smp: rework absolute lowcore access"
  Revert "s390/smp,ptdump: add absolute lowcore markers"
  s390/unwind: fix fgraph return address recovery
  s390/nmi: use irqentry_nmi_enter()/irqentry_nmi_exit()
  s390: add ELF note type for encrypted CPU state of a PV VCPU
  s390/smp,ptdump: add absolute lowcore markers
  s390/smp: rework absolute lowcore access
  s390/setup: rearrange absolute lowcore initialization
  s390/boot: cleanup adjust_to_uv_max() function
  s390/smp: enforce lowcore protection on CPU restart
  s390/tape: fix comment typo
  s390/hmcdrv: fix Kconfig "its" grammar
  s390/docs: fix warnings for vfio_ap driver doc
  s390/docs: fix warnings for vfio_ap driver lock usage doc
  s390/crash: support multi-segment iterators
  s390/crash: use static swap buffer for copy_to_user_real()
  s390/crash: move copy_to_user_real() to crash_dump.c
  s390/zcore: fix race when reading from hardware system area
  s390/crash: fix incorrect number of bytes to copy to user space
  ...

1 files changed, 23 insertions, 8 deletions

diff --git a/drivers/s390/crypto/ap_bus.c b/drivers/s390/crypto/ap_bus.c
index 95cfdeab5baf..8f1d1cf23d44 100644
--- a/drivers/s390/crypto/ap_bus.c
+++ b/drivers/s390/crypto/ap_bus.c
@@ -838,6 +838,17 @@ static void ap_bus_revise_bindings(void)
 	bus_for_each_dev(&ap_bus_type, NULL, NULL, __ap_revise_reserved);
 }
 
+/**
+ * ap_owned_by_def_drv: indicates whether an AP adapter is reserved for the
+ *			default host driver or not.
+ * @card: the APID of the adapter card to check
+ * @queue: the APQI of the queue to check
+ *
+ * Note: the ap_perms_mutex must be locked by the caller of this function.
+ *
+ * Return: an int specifying whether the AP adapter is reserved for the host (1)
+ *	   or not (0).
+ */
 int ap_owned_by_def_drv(int card, int queue)
 {
 	int rc = 0;
@@ -845,25 +856,31 @@ int ap_owned_by_def_drv(int card, int queue)
 	if (card < 0 || card >= AP_DEVICES || queue < 0 || queue >= AP_DOMAINS)
 		return -EINVAL;
 
-	mutex_lock(&ap_perms_mutex);
-
 	if (test_bit_inv(card, ap_perms.apm) &&
 	    test_bit_inv(queue, ap_perms.aqm))
 		rc = 1;
 
-	mutex_unlock(&ap_perms_mutex);
-
 	return rc;
 }
 EXPORT_SYMBOL(ap_owned_by_def_drv);
 
+/**
+ * ap_apqn_in_matrix_owned_by_def_drv: indicates whether every APQN contained in
+ *				       a set is reserved for the host drivers
+ *				       or not.
+ * @apm: a bitmap specifying a set of APIDs comprising the APQNs to check
+ * @aqm: a bitmap specifying a set of APQIs comprising the APQNs to check
+ *
+ * Note: the ap_perms_mutex must be locked by the caller of this function.
+ *
+ * Return: an int specifying whether each APQN is reserved for the host (1) or
+ *	   not (0)
+ */
 int ap_apqn_in_matrix_owned_by_def_drv(unsigned long *apm,
 				       unsigned long *aqm)
 {
 	int card, queue, rc = 0;
 
-	mutex_lock(&ap_perms_mutex);
-
 	for (card = 0; !rc && card < AP_DEVICES; card++)
 		if (test_bit_inv(card, apm) &&
 		    test_bit_inv(card, ap_perms.apm))
@@ -872,8 +889,6 @@ int ap_apqn_in_matrix_owned_by_def_drv(unsigned long *apm,
 				    test_bit_inv(queue, ap_perms.aqm))
 					rc = 1;
 
-	mutex_unlock(&ap_perms_mutex);
-
 	return rc;
 }
 EXPORT_SYMBOL(ap_apqn_in_matrix_owned_by_def_drv);