Merge tag 's390-6.13-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

Pull s390 updates from Heiko Carstens:

 - Add firmware sysfs interface which allows user space to retrieve the
   dump area size of the machine

 - Add 'measurement_chars_full' CHPID sysfs attribute to make the
   complete associated Channel-Measurements Characteristics Block
   available

 - Add virtio-mem support

 - Move gmap aka KVM page fault handling from the main fault handler to
   KVM code. This is the first step to make s390 KVM page fault handling
   similar to other architectures. With this first step the main fault
   handler does not have any special handling anymore, and therefore
   convert it to support LOCK_MM_AND_FIND_VMA

 - With gcc 14 s390 support for flag output operand support for inline
   assemblies was added. This allows for several optimizations:

     - Provide a cmpxchg inline assembly which makes use of this, and
       provide all variants of arch_try_cmpxchg() so that the compiler
       can generate slightly better code

     - Convert a few cmpxchg() loops to try_cmpxchg() loops

     - Similar to x86 add a CC_OUT() helper macro (and other macros),
       and convert all inline assemblies to make use of them, so that
       depending on compiler version better code can be generated

 - List installed host-key hashes in sysfs if the machine supports the
   Query Ultravisor Keys UVC

 - Add 'Retrieve Secret' ioctl which allows user space in protected
   execution guests to retrieve previously stored secrets from the
   Ultravisor

 - Add pkey-uv module which supports the conversion of Ultravisor
   retrievable secrets to protected keys

 - Extend the existing paes cipher to exploit the full AES-XTS hardware
   acceleration introduced with message-security assist extension 10

 - Convert hopefully all sysfs show functions to use sysfs_emit() so
   that the constant flow of such patches stop

 - For PCI devices make use of the newly added Topology ID attribute to
   enable whole card multi-function support despite the change to PCHID
   per port. Additionally improve the overall robustness and usability
   of the multifunction support

 - Various other small improvements, fixes, and cleanups

* tag 's390-6.13-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (133 commits)
  s390/cio/ioasm: Convert to use flag output macros
  s390/cio/qdio: Convert to use flag output macros
  s390/sclp: Convert to use flag output macros
  s390/dasd: Convert to use flag output macros
  s390/boot/physmem: Convert to use flag output macros
  s390/pci: Convert to use flag output macros
  s390/kvm: Convert to use flag output macros
  s390/extmem: Convert to use flag output macros
  s390/string: Convert to use flag output macros
  s390/diag: Convert to use flag output macros
  s390/irq: Convert to use flag output macros
  s390/smp: Convert to use flag output macros
  s390/uv: Convert to use flag output macros
  s390/pai: Convert to use flag output macros
  s390/mm: Convert to use flag output macros
  s390/cpu_mf: Convert to use flag output macros
  s390/cpcmd: Convert to use flag output macros
  s390/topology: Convert to use flag output macros
  s390/time: Convert to use flag output macros
  s390/pageattr: Convert to use flag output macros
  ...

9 files changed, 156 insertions, 55 deletions

diff --git a/drivers/s390/char/con3270.c b/drivers/s390/char/con3270.c
index 053102d0fcd2..ae1b9aa3a2b5 100644
--- a/drivers/s390/char/con3270.c
+++ b/drivers/s390/char/con3270.c
@@ -528,7 +528,7 @@ static void tty3270_update(struct timer_list *t)
 	u8 cmd = TC_WRITE;
 	int rc, len;
 
-	wrq = xchg(&tp->write, 0);
+	wrq = xchg(&tp->write, NULL);
 	if (!wrq) {
 		tty3270_set_timer(tp, 1);
 		return;
@@ -746,7 +746,7 @@ static void tty3270_issue_read(struct tty3270 *tp, int lock)
 	struct raw3270_request *rrq;
 	int rc;
 
-	rrq = xchg(&tp->read, 0);
+	rrq = xchg(&tp->read, NULL);
 	if (!rrq)
 		/* Read already scheduled. */
 		return;
diff --git a/drivers/s390/char/sclp.h b/drivers/s390/char/sclp.h
index 6a23ec286c70..6c91e422927f 100644
--- a/drivers/s390/char/sclp.h
+++ b/drivers/s390/char/sclp.h
@@ -14,6 +14,7 @@
 #include <asm/asm-extable.h>
 #include <asm/sclp.h>
 #include <asm/ebcdic.h>
+#include <asm/asm.h>
 
 /* maximum number of pages concerning our own memory management */
 #define MAX_KMEM_PAGES (sizeof(unsigned long) << 3)
@@ -325,19 +326,22 @@ struct read_info_sccb * __init sclp_early_get_info(void);
 /* Perform service call. Return 0 on success, non-zero otherwise. */
 static inline int sclp_service_call(sclp_cmdw_t command, void *sccb)
 {
-	int cc = 4; /* Initialize for program check handling */
+	int cc, exception;
 
+	exception = 1;
 	asm volatile(
-		"0:	.insn	rre,0xb2200000,%1,%2\n"	 /* servc %1,%2 */
-		"1:	ipm	%0\n"
-		"	srl	%0,28\n"
+		"0:	.insn	rre,0xb2200000,%[cmd],%[sccb]\n" /* servc */
+		"1:	lhi	%[exc],0\n"
 		"2:\n"
+		CC_IPM(cc)
 		EX_TABLE(0b, 2b)
 		EX_TABLE(1b, 2b)
-		: "+&d" (cc) : "d" (command), "a" (__pa(sccb))
-		: "cc", "memory");
-	if (cc == 4)
+		: CC_OUT(cc, cc), [exc] "+d" (exception)
+		: [cmd] "d" (command), [sccb] "a" (__pa(sccb))
+		: CC_CLOBBER_LIST("memory"));
+	if (exception)
 		return -EINVAL;
+	cc = CC_TRANSFORM(cc);
 	if (cc == 3)
 		return -EIO;
 	if (cc == 2)
diff --git a/drivers/s390/char/sclp_cpi_sys.c b/drivers/s390/char/sclp_cpi_sys.c
index f60d7ea8268d..d8f91aab11e8 100644
--- a/drivers/s390/char/sclp_cpi_sys.c
+++ b/drivers/s390/char/sclp_cpi_sys.c
@@ -223,7 +223,7 @@ static ssize_t system_name_show(struct kobject *kobj,
 	int rc;
 
 	mutex_lock(&sclp_cpi_mutex);
-	rc = snprintf(page, PAGE_SIZE, "%s\n", system_name);
+	rc = sysfs_emit(page, "%s\n", system_name);
 	mutex_unlock(&sclp_cpi_mutex);
 	return rc;
 }
@@ -255,7 +255,7 @@ static ssize_t sysplex_name_show(struct kobject *kobj,
 	int rc;
 
 	mutex_lock(&sclp_cpi_mutex);
-	rc = snprintf(page, PAGE_SIZE, "%s\n", sysplex_name);
+	rc = sysfs_emit(page, "%s\n", sysplex_name);
 	mutex_unlock(&sclp_cpi_mutex);
 	return rc;
 }
@@ -287,7 +287,7 @@ static ssize_t system_type_show(struct kobject *kobj,
 	int rc;
 
 	mutex_lock(&sclp_cpi_mutex);
-	rc = snprintf(page, PAGE_SIZE, "%s\n", system_type);
+	rc = sysfs_emit(page, "%s\n", system_type);
 	mutex_unlock(&sclp_cpi_mutex);
 	return rc;
 }
@@ -321,7 +321,7 @@ static ssize_t system_level_show(struct kobject *kobj,
 	mutex_lock(&sclp_cpi_mutex);
 	level = system_level;
 	mutex_unlock(&sclp_cpi_mutex);
-	return snprintf(page, PAGE_SIZE, "%#018llx\n", level);
+	return sysfs_emit(page, "%#018llx\n", level);
 }
 
 static ssize_t system_level_store(struct kobject *kobj,
diff --git a/drivers/s390/char/sclp_ocf.c b/drivers/s390/char/sclp_ocf.c
index d35f10ea5b52..ca6c5260dc53 100644
--- a/drivers/s390/char/sclp_ocf.c
+++ b/drivers/s390/char/sclp_ocf.c
@@ -101,7 +101,7 @@ static ssize_t cpc_name_show(struct kobject *kobj,
 	sclp_ocf_cpc_name_copy(name);
 	name[OCF_LENGTH_CPC_NAME] = 0;
 	EBCASC(name, OCF_LENGTH_CPC_NAME);
-	return snprintf(page, PAGE_SIZE, "%s\n", name);
+	return sysfs_emit(page, "%s\n", name);
 }
 
 static struct kobj_attribute cpc_name_attr =
@@ -113,7 +113,7 @@ static ssize_t hmc_network_show(struct kobject *kobj,
 	int rc;
 
 	spin_lock_irq(&sclp_ocf_lock);
-	rc = snprintf(page, PAGE_SIZE, "%s\n", hmc_network);
+	rc = sysfs_emit(page, "%s\n", hmc_network);
 	spin_unlock_irq(&sclp_ocf_lock);
 	return rc;
 }
diff --git a/drivers/s390/char/sclp_pci.c b/drivers/s390/char/sclp_pci.c
index a3e5a5fb0c1e..c3466a8c56bb 100644
--- a/drivers/s390/char/sclp_pci.c
+++ b/drivers/s390/char/sclp_pci.c
@@ -27,6 +27,7 @@
 #define SCLP_ERRNOTIFY_AQ_RESET			0
 #define SCLP_ERRNOTIFY_AQ_REPAIR		1
 #define SCLP_ERRNOTIFY_AQ_INFO_LOG		2
+#define SCLP_ERRNOTIFY_AQ_OPTICS_DATA		3
 
 static DEFINE_MUTEX(sclp_pci_mutex);
 static struct sclp_register sclp_pci_event = {
@@ -116,6 +117,7 @@ static int sclp_pci_check_report(struct zpci_report_error_header *report)
 	case SCLP_ERRNOTIFY_AQ_RESET:
 	case SCLP_ERRNOTIFY_AQ_REPAIR:
 	case SCLP_ERRNOTIFY_AQ_INFO_LOG:
+	case SCLP_ERRNOTIFY_AQ_OPTICS_DATA:
 		break;
 	default:
 		return -EINVAL;
diff --git a/drivers/s390/char/tape_core.c b/drivers/s390/char/tape_core.c
index a6d2a4792185..ce8a440598a8 100644
--- a/drivers/s390/char/tape_core.c
+++ b/drivers/s390/char/tape_core.c
@@ -96,7 +96,7 @@ tape_medium_state_show(struct device *dev, struct device_attribute *attr, char *
 	struct tape_device *tdev;
 
 	tdev = dev_get_drvdata(dev);
-	return scnprintf(buf, PAGE_SIZE, "%i\n", tdev->medium_state);
+	return sysfs_emit(buf, "%i\n", tdev->medium_state);
 }
 
 static
@@ -108,7 +108,7 @@ tape_first_minor_show(struct device *dev, struct device_attribute *attr, char *b
 	struct tape_device *tdev;
 
 	tdev = dev_get_drvdata(dev);
-	return scnprintf(buf, PAGE_SIZE, "%i\n", tdev->first_minor);
+	return sysfs_emit(buf, "%i\n", tdev->first_minor);
 }
 
 static
@@ -120,8 +120,8 @@ tape_state_show(struct device *dev, struct device_attribute *attr, char *buf)
 	struct tape_device *tdev;
 
 	tdev = dev_get_drvdata(dev);
-	return scnprintf(buf, PAGE_SIZE, "%s\n", (tdev->first_minor < 0) ?
-		"OFFLINE" : tape_state_verbose[tdev->tape_state]);
+	return sysfs_emit(buf, "%s\n", (tdev->first_minor < 0) ?
+			  "OFFLINE" : tape_state_verbose[tdev->tape_state]);
 }
 
 static
@@ -135,17 +135,17 @@ tape_operation_show(struct device *dev, struct device_attribute *attr, char *buf
 
 	tdev = dev_get_drvdata(dev);
 	if (tdev->first_minor < 0)
-		return scnprintf(buf, PAGE_SIZE, "N/A\n");
+		return sysfs_emit(buf, "N/A\n");
 
 	spin_lock_irq(get_ccwdev_lock(tdev->cdev));
 	if (list_empty(&tdev->req_queue))
-		rc = scnprintf(buf, PAGE_SIZE, "---\n");
+		rc = sysfs_emit(buf, "---\n");
 	else {
 		struct tape_request *req;
 
 		req = list_entry(tdev->req_queue.next, struct tape_request,
 			list);
-		rc = scnprintf(buf,PAGE_SIZE, "%s\n", tape_op_verbose[req->op]);
+		rc = sysfs_emit(buf, "%s\n", tape_op_verbose[req->op]);
 	}
 	spin_unlock_irq(get_ccwdev_lock(tdev->cdev));
 	return rc;
@@ -161,7 +161,7 @@ tape_blocksize_show(struct device *dev, struct device_attribute *attr, char *buf
 
 	tdev = dev_get_drvdata(dev);
 
-	return scnprintf(buf, PAGE_SIZE, "%i\n", tdev->char_data.block_size);
+	return sysfs_emit(buf, "%i\n", tdev->char_data.block_size);
 }
 
 static
diff --git a/drivers/s390/char/uvdevice.c b/drivers/s390/char/uvdevice.c
index f598edc5f251..2b83fb6dc1d7 100644
--- a/drivers/s390/char/uvdevice.c
+++ b/drivers/s390/char/uvdevice.c
@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0
 /*
- *  Copyright IBM Corp. 2022
+ *  Copyright IBM Corp. 2022, 2024
  *  Author(s): Steffen Eiden <seiden@linux.ibm.com>
  *
  *  This file provides a Linux misc device to give userspace access to some
@@ -40,6 +40,7 @@ static const u32 ioctl_nr_to_uvc_bit[] __initconst = {
 	[UVIO_IOCTL_ADD_SECRET_NR] = BIT_UVC_CMD_ADD_SECRET,
 	[UVIO_IOCTL_LIST_SECRETS_NR] = BIT_UVC_CMD_LIST_SECRETS,
 	[UVIO_IOCTL_LOCK_SECRETS_NR] = BIT_UVC_CMD_LOCK_SECRETS,
+	[UVIO_IOCTL_RETR_SECRET_NR] = BIT_UVC_CMD_RETR_ATTEST,
 };
 
 static_assert(ARRAY_SIZE(ioctl_nr_to_uvc_bit) == UVIO_IOCTL_NUM_IOCTLS);
@@ -62,11 +63,13 @@ static void __init set_supp_uv_cmds(unsigned long *supp_uv_cmds)
 }
 
 /**
- * uvio_uvdev_info() - get information about the uvdevice
+ * uvio_uvdev_info() - Get information about the uvdevice
  *
  * @uv_ioctl: ioctl control block
  *
  * Lists all IOCTLs that are supported by this uvdevice
+ *
+ * Return: 0 on success or a negative error code on error
  */
 static int uvio_uvdev_info(struct uvio_ioctl_cb *uv_ioctl)
 {
@@ -177,7 +180,7 @@ static int get_uvio_attest(struct uvio_ioctl_cb *uv_ioctl, struct uvio_attest *u
  *
  * Context: might sleep
  *
- * Return: 0 on success or a negative error code on error.
+ * Return: 0 on success or a negative error code on error
  */
 static int uvio_attestation(struct uvio_ioctl_cb *uv_ioctl)
 {
@@ -237,7 +240,8 @@ out:
 	return ret;
 }
 
-/** uvio_add_secret() - perform an Add Secret UVC
+/**
+ * uvio_add_secret() - Perform an Add Secret UVC
  *
  * @uv_ioctl: ioctl control block
  *
@@ -260,7 +264,7 @@ out:
  *
  * Context: might sleep
  *
- * Return: 0 on success or a negative error code on error.
+ * Return: 0 on success or a negative error code on error
  */
 static int uvio_add_secret(struct uvio_ioctl_cb *uv_ioctl)
 {
@@ -296,7 +300,44 @@ out:
 	return ret;
 }
 
-/** uvio_list_secrets() - perform a List Secret UVC
+/*
+ * Do the actual secret list creation. Calls the list secrets UVC until there
+ * is no more space in the user buffer, or the list ends.
+ */
+static int uvio_get_list(void *zpage, struct uvio_ioctl_cb *uv_ioctl)
+{
+	const size_t data_off = offsetof(struct uv_secret_list, secrets);
+	u8 __user *user_buf = (u8 __user *)uv_ioctl->argument_addr;
+	struct uv_secret_list *list = zpage;
+	u16 num_secrets_stored = 0;
+	size_t user_off = data_off;
+	size_t copy_len;
+
+	do {
+		uv_list_secrets(list, list->next_secret_idx, &uv_ioctl->uv_rc,
+				&uv_ioctl->uv_rrc);
+		if (uv_ioctl->uv_rc != UVC_RC_EXECUTED &&
+		    uv_ioctl->uv_rc != UVC_RC_MORE_DATA)
+			break;
+
+		copy_len = sizeof(list->secrets[0]) * list->num_secr_stored;
+		if (copy_to_user(user_buf + user_off, list->secrets, copy_len))
+			return -EFAULT;
+
+		user_off += copy_len;
+		num_secrets_stored += list->num_secr_stored;
+	} while (uv_ioctl->uv_rc == UVC_RC_MORE_DATA &&
+		 user_off + sizeof(*list) <= uv_ioctl->argument_len);
+
+	list->num_secr_stored = num_secrets_stored;
+	if (copy_to_user(user_buf, list, data_off))
+		return -EFAULT;
+	return 0;
+}
+
+/**
+ * uvio_list_secrets() - Perform a List Secret UVC
+ *
  * @uv_ioctl: ioctl control block
  *
  * uvio_list_secrets() performs the List Secret Ultravisor Call. It verifies
@@ -307,45 +348,43 @@ out:
  *
  * The argument specifies the location for the result of the UV-Call.
  *
+ * Argument length must be a multiple of a page.
+ * The list secrets IOCTL will call the list UVC multiple times and fill
+ * the provided user-buffer with list elements until either the list ends or
+ * the buffer is full. The list header is merged over all list header from the
+ * individual UVCs.
+ *
  * If the List Secrets UV facility is not present, UV will return invalid
  * command rc. This won't be fenced in the driver and does not result in a
  * negative return value.
  *
  * Context: might sleep
  *
- * Return: 0 on success or a negative error code on error.
+ * Return: 0 on success or a negative error code on error
  */
 static int uvio_list_secrets(struct uvio_ioctl_cb *uv_ioctl)
 {
-	void __user *user_buf_arg = (void __user *)uv_ioctl->argument_addr;
-	struct uv_cb_guest_addr uvcb = {
-		.header.len = sizeof(uvcb),
-		.header.cmd = UVC_CMD_LIST_SECRETS,
-	};
-	void *secrets = NULL;
-	int ret = 0;
+	void *zpage;
+	int rc;
 
-	if (uv_ioctl->argument_len != UVIO_LIST_SECRETS_LEN)
+	if (uv_ioctl->argument_len == 0 ||
+	    uv_ioctl->argument_len % UVIO_LIST_SECRETS_LEN != 0)
 		return -EINVAL;
 
-	secrets = kvzalloc(UVIO_LIST_SECRETS_LEN, GFP_KERNEL);
-	if (!secrets)
+	zpage = (void *)get_zeroed_page(GFP_KERNEL);
+	if (!zpage)
 		return -ENOMEM;
 
-	uvcb.addr = (u64)secrets;
-	uv_call_sched(0, (u64)&uvcb);
-	uv_ioctl->uv_rc = uvcb.header.rc;
-	uv_ioctl->uv_rrc = uvcb.header.rrc;
-
-	if (copy_to_user(user_buf_arg, secrets, UVIO_LIST_SECRETS_LEN))
-		ret = -EFAULT;
+	rc = uvio_get_list(zpage, uv_ioctl);
 
-	kvfree(secrets);
-	return ret;
+	free_page((unsigned long)zpage);
+	return rc;
 }
 
-/** uvio_lock_secrets() - perform a Lock Secret Store UVC
- * @uv_ioctl: ioctl control block
+/**
+ * uvio_lock_secrets() - Perform a Lock Secret Store UVC
+ *
+ * @ioctl: ioctl control block
  *
  * uvio_lock_secrets() performs the Lock Secret Store Ultravisor Call. It
  * performs the UV-call and copies the return codes to the ioctl control block.
@@ -360,7 +399,7 @@ static int uvio_list_secrets(struct uvio_ioctl_cb *uv_ioctl)
  *
  * Context: might sleep
  *
- * Return: 0 on success or a negative error code on error.
+ * Return: 0 on success or a negative error code on error
  */
 static int uvio_lock_secrets(struct uvio_ioctl_cb *ioctl)
 {
@@ -379,6 +418,59 @@ static int uvio_lock_secrets(struct uvio_ioctl_cb *ioctl)
 	return 0;
 }
 
+/**
+ * uvio_retr_secret() - Perform a retrieve secret UVC
+ *
+ * @uv_ioctl: ioctl control block.
+ *
+ * uvio_retr_secret() performs the Retrieve Secret Ultravisor Call.
+ * The first two bytes of the argument specify the index of the secret to be
+ * retrieved. The retrieved secret is copied into the argument buffer if there
+ * is enough space.
+ * The argument length must be at least two bytes and at max 8192 bytes.
+ *
+ * Context: might sleep
+ *
+ * Return: 0 on success or a negative error code on error
+ */
+static int uvio_retr_secret(struct uvio_ioctl_cb *uv_ioctl)
+{
+	u16 __user *user_index = (u16 __user *)uv_ioctl->argument_addr;
+	struct uv_cb_retr_secr uvcb = {
+		.header.len = sizeof(uvcb),
+		.header.cmd = UVC_CMD_RETR_SECRET,
+	};
+	u32 buf_len = uv_ioctl->argument_len;
+	void *buf = NULL;
+	int ret;
+
+	if (buf_len > UVIO_RETR_SECRET_MAX_LEN || buf_len < sizeof(*user_index))
+		return -EINVAL;
+
+	buf = kvzalloc(buf_len, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	ret = -EFAULT;
+	if (get_user(uvcb.secret_idx, user_index))
+		goto err;
+
+	uvcb.buf_addr = (u64)buf;
+	uvcb.buf_size = buf_len;
+	uv_call_sched(0, (u64)&uvcb);
+
+	if (copy_to_user((__user void *)uv_ioctl->argument_addr, buf, buf_len))
+		goto err;
+
+	ret = 0;
+	uv_ioctl->uv_rc = uvcb.header.rc;
+	uv_ioctl->uv_rrc = uvcb.header.rrc;
+
+err:
+	kvfree_sensitive(buf, buf_len);
+	return ret;
+}
+
 static int uvio_copy_and_check_ioctl(struct uvio_ioctl_cb *ioctl, void __user *argp,
 				     unsigned long cmd)
 {
@@ -432,6 +524,9 @@ static long uvio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 	case UVIO_IOCTL_LOCK_SECRETS_NR:
 		ret = uvio_lock_secrets(&uv_ioctl);
 		break;
+	case UVIO_IOCTL_RETR_SECRET_NR:
+		ret = uvio_retr_secret(&uv_ioctl);
+		break;
 	default:
 		ret = -ENOIOCTLCMD;
 		break;
diff --git a/drivers/s390/char/vmlogrdr.c b/drivers/s390/char/vmlogrdr.c
index bd5cecc44123..3dd50ac9c5b0 100644
--- a/drivers/s390/char/vmlogrdr.c
+++ b/drivers/s390/char/vmlogrdr.c
@@ -531,7 +531,7 @@ static ssize_t vmlogrdr_autopurge_show(struct device *dev,
 				       char *buf)
 {
 	struct vmlogrdr_priv_t *priv = dev_get_drvdata(dev);
-	return sprintf(buf, "%u\n", priv->autopurge);
+	return sysfs_emit(buf, "%u\n", priv->autopurge);
 }
 
 
@@ -605,7 +605,7 @@ static ssize_t vmlogrdr_autorecording_show(struct device *dev,
 					   char *buf)
 {
 	struct vmlogrdr_priv_t *priv = dev_get_drvdata(dev);
-	return sprintf(buf, "%u\n", priv->autorecording);
+	return sysfs_emit(buf, "%u\n", priv->autorecording);
 }
 
 
diff --git a/drivers/s390/char/vmur.c b/drivers/s390/char/vmur.c
index fe94dec427b6..90ba7a2b9cb4 100644
--- a/drivers/s390/char/vmur.c
+++ b/drivers/s390/char/vmur.c
@@ -345,7 +345,7 @@ static ssize_t ur_attr_reclen_show(struct device *dev,
 	urd = urdev_get_from_cdev(to_ccwdev(dev));
 	if (!urd)
 		return -ENODEV;
-	rc = sprintf(buf, "%zu\n", urd->reclen);
+	rc = sysfs_emit(buf, "%zu\n", urd->reclen);
 	urdev_put(urd);
 	return rc;
 }