Hi Tony,

I love your patch! Perhaps something to improve:

[auto build test WARNING on kvms390/next]
[also build test WARNING on linus/master v5.7]
[cannot apply to s390/features linux/master next-20200605]
[if your patch is applied to the wrong git tree, please drop us a note to help
improve the system. BTW, we also suggest to use '--base' option to specify the
base tree in git format-patch, please see https://stackoverflow.com/a/37406982]

url:    https://github.com/0day-ci/linux/commits/Tony-Krowiak/s390-vfio-ap-dynamic-configuration-support/20200606-054350
base:   https://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux.git next
config: s390-allyesconfig (attached as .config)
compiler: s390-linux-gcc (GCC) 9.3.0
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=s390 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All warnings (new ones prefixed by >>, old ones prefixed by <<):

drivers/s390/crypto/ap_bus.c: In function '__ap_revise_reserved':
drivers/s390/crypto/ap_bus.c:594:6: warning: variable 'rc' set but not used [-Wunused-but-set-variable]
594 |  int rc, card, queue, devres, drvres;
|      ^~
drivers/s390/crypto/ap_bus.c: At top level:
>> drivers/s390/crypto/ap_bus.c:1106:5: warning: no previous prototype for '__verify_card_reservations' [-Wmissing-prototypes]
1106 | int __verify_card_reservations(struct device_driver *drv, void *data)
|     ^~~~~~~~~~~~~~~~~~~~~~~~~~
>> drivers/s390/crypto/ap_bus.c:1195:5: warning: no previous prototype for '__verify_queue_reservations' [-Wmissing-prototypes]
1195 | int __verify_queue_reservations(struct device_driver *drv, void *data)
|     ^~~~~~~~~~~~~~~~~~~~~~~~~~~

vim +/__verify_card_reservations +1106 drivers/s390/crypto/ap_bus.c

  1105	
> 1106	int __verify_card_reservations(struct device_driver *drv, void *data)
  1107	{
  1108		int rc = 0;
  1109		struct ap_driver *ap_drv = to_ap_drv(drv);
  1110		unsigned long *newapm = (unsigned long *)data;
  1111	
  1112		/*
  1113		 * No need to verify whether the driver is using the queues if it is the
  1114		 * default driver.
  1115		 */
  1116		if (ap_drv->flags & AP_DRIVER_FLAG_DEFAULT)
  1117			return 0;
  1118	
  1119		/* The non-default driver's module must be loaded */
  1120		if (!try_module_get(drv->owner))
  1121			return 0;
  1122	
  1123		if (ap_drv->in_use)
  1124			if (ap_drv->in_use(newapm, ap_perms.aqm))
  1125				rc = -EADDRINUSE;
  1126	
  1127		module_put(drv->owner);
  1128	
  1129		return rc;
  1130	}
  1131	
  1132	static int apmask_commit(unsigned long *newapm)
  1133	{
  1134		int rc;
  1135		unsigned long reserved[BITS_TO_LONGS(AP_DEVICES)];
  1136	
  1137		/*
  1138		 * Check if any bits in the apmask have been set which will
  1139		 * result in queues being removed from non-default drivers
  1140		 */
  1141		if (bitmap_andnot(reserved, newapm, ap_perms.apm, AP_DEVICES)) {
  1142			rc = bus_for_each_drv(&ap_bus_type, NULL, reserved,
  1143					      __verify_card_reservations);
  1144			if (rc)
  1145				return rc;
  1146		}
  1147	
  1148		memcpy(ap_perms.apm, newapm, APMASKSIZE);
  1149	
  1150		return 0;
  1151	}
  1152	
  1153	static ssize_t apmask_store(struct bus_type *bus, const char *buf,
  1154				    size_t count)
  1155	{
  1156		int rc;
  1157		DECLARE_BITMAP(newapm, AP_DEVICES);
  1158	
  1159		if (mutex_lock_interruptible(&ap_perms_mutex))
  1160			return -ERESTARTSYS;
  1161	
  1162		rc = ap_parse_bitmap_str(buf, ap_perms.apm, AP_DEVICES, newapm);
  1163		if (rc)
  1164			goto done;
  1165	
  1166		rc = apmask_commit(newapm);
  1167	
  1168	done:
  1169		mutex_unlock(&ap_perms_mutex);
  1170		if (rc)
  1171			return rc;
  1172	
  1173		ap_bus_revise_bindings();
  1174	
  1175		return count;
  1176	}
  1177	
  1178	static BUS_ATTR_RW(apmask);
  1179	
  1180	static ssize_t aqmask_show(struct bus_type *bus, char *buf)
  1181	{
  1182		int rc;
  1183	
  1184		if (mutex_lock_interruptible(&ap_perms_mutex))
  1185			return -ERESTARTSYS;
  1186		rc = scnprintf(buf, PAGE_SIZE,
  1187			       "0x%016lx%016lx%016lx%016lx\n",
  1188			       ap_perms.aqm[0], ap_perms.aqm[1],
  1189			       ap_perms.aqm[2], ap_perms.aqm[3]);
  1190		mutex_unlock(&ap_perms_mutex);
  1191	
  1192		return rc;
  1193	}
  1194	
> 1195	int __verify_queue_reservations(struct device_driver *drv, void *data)
  1196	{
  1197		int rc = 0;
  1198		struct ap_driver *ap_drv = to_ap_drv(drv);
  1199		unsigned long *newaqm = (unsigned long *)data;
  1200	
  1201		/*
  1202		 * If the reserved bits do not identify queues reserved for use by the
  1203		 * non-default driver, there is no need to verify the driver is using
  1204		 * the queues.
  1205		 */
  1206		if (ap_drv->flags & AP_DRIVER_FLAG_DEFAULT)
  1207			return 0;
  1208	
  1209		/* The non-default driver's module must be loaded */
  1210		if (!try_module_get(drv->owner))
  1211			return 0;
  1212	
  1213		if (ap_drv->in_use)
  1214			if (ap_drv->in_use(ap_perms.apm, newaqm))
  1215				rc = -EADDRINUSE;
  1216	
  1217		module_put(drv->owner);
  1218	
  1219		return rc;
  1220	}
  1221	

---
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