5 files changed, 447 insertions, 452 deletions

diff --git a/drivers/s390/char/Makefile b/drivers/s390/char/Makefile
index 81d6744e1861..dcbd51152ee3 100644
--- a/drivers/s390/char/Makefile
+++ b/drivers/s390/char/Makefile
@@ -21,6 +21,7 @@ obj-y += ctrlchar.o keyboard.o defkeymap.o sclp.o sclp_rw.o sclp_quiesce.o \
 	 sclp_cmd.o sclp_config.o sclp_cpi_sys.o sclp_ocf.o sclp_ctl.o \
 	 sclp_early.o sclp_early_core.o sclp_sd.o
 
+obj-$(CONFIG_MEMORY_HOTPLUG) += sclp_mem.o
 obj-$(CONFIG_TN3270) += raw3270.o con3270.o
 obj-$(CONFIG_TN3270_FS) += fs3270.o
 
diff --git a/drivers/s390/char/hmcdrv_dev.c b/drivers/s390/char/hmcdrv_dev.c
index e069dd685899..b26fcf6849f2 100644
--- a/drivers/s390/char/hmcdrv_dev.c
+++ b/drivers/s390/char/hmcdrv_dev.c
@@ -244,24 +244,17 @@ static ssize_t hmcdrv_dev_write(struct file *fp, const char __user *ubuf,
 				size_t len, loff_t *pos)
 {
 	ssize_t retlen;
+	void *pdata;
 
 	pr_debug("writing file '/dev/%pD' at pos. %lld with length %zd\n",
 		 fp, (long long) *pos, len);
 
 	if (!fp->private_data) { /* first expect a cmd write */
-		fp->private_data = kmalloc(len + 1, GFP_KERNEL);
-
-		if (!fp->private_data)
-			return -ENOMEM;
-
-		if (!copy_from_user(fp->private_data, ubuf, len)) {
-			((char *)fp->private_data)[len] = '\0';
-			return len;
-		}
-
-		kfree(fp->private_data);
-		fp->private_data = NULL;
-		return -EFAULT;
+		pdata = memdup_user_nul(ubuf, len);
+		if (IS_ERR(pdata))
+			return PTR_ERR(pdata);
+		fp->private_data = pdata;
+		return len;
 	}
 
 	retlen = hmcdrv_dev_transfer((char *) fp->private_data,
diff --git a/drivers/s390/char/sclp_cmd.c b/drivers/s390/char/sclp_cmd.c
index 16469678548f..3480198eac02 100644
--- a/drivers/s390/char/sclp_cmd.c
+++ b/drivers/s390/char/sclp_cmd.c
@@ -8,31 +8,46 @@
 #define KMSG_COMPONENT "sclp_cmd"
 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
 
-#include <linux/cpufeature.h>
 #include <linux/completion.h>
-#include <linux/init.h>
-#include <linux/errno.h>
 #include <linux/err.h>
+#include <linux/errno.h>
+#include <linux/init.h>
 #include <linux/slab.h>
 #include <linux/string.h>
-#include <linux/mm.h>
-#include <linux/mmzone.h>
-#include <linux/memory.h>
-#include <linux/memory_hotplug.h>
-#include <linux/module.h>
-#include <asm/ctlreg.h>
 #include <asm/chpid.h>
-#include <asm/setup.h>
-#include <asm/page.h>
+#include <asm/ctlreg.h>
 #include <asm/sclp.h>
-#include <asm/numa.h>
-#include <asm/facility.h>
-#include <asm/page-states.h>
 
 #include "sclp.h"
 
-#define SCLP_CMDW_ASSIGN_STORAGE	0x000d0001
-#define SCLP_CMDW_UNASSIGN_STORAGE	0x000c0001
+/* CPU configuration related functions */
+#define SCLP_CMDW_CONFIGURE_CPU			0x00110001
+#define SCLP_CMDW_DECONFIGURE_CPU		0x00100001
+/* Channel path configuration related functions */
+#define SCLP_CMDW_CONFIGURE_CHPATH		0x000f0001
+#define SCLP_CMDW_DECONFIGURE_CHPATH		0x000e0001
+#define SCLP_CMDW_READ_CHPATH_INFORMATION	0x00030001
+
+struct cpu_configure_sccb {
+	struct sccb_header header;
+} __packed __aligned(8);
+
+struct chp_cfg_sccb {
+	struct sccb_header header;
+	u8 ccm;
+	u8 reserved[6];
+	u8 cssid;
+} __packed;
+
+struct chp_info_sccb {
+	struct sccb_header header;
+	u8 recognized[SCLP_CHP_INFO_MASK_SIZE];
+	u8 standby[SCLP_CHP_INFO_MASK_SIZE];
+	u8 configured[SCLP_CHP_INFO_MASK_SIZE];
+	u8 ccm;
+	u8 reserved[6];
+	u8 cssid;
+} __packed;
 
 static void sclp_sync_callback(struct sclp_req *req, void *data)
 {
@@ -64,13 +79,11 @@ int sclp_sync_request_timeout(sclp_cmdw_t cmd, void *sccb, int timeout)
 	request->callback_data = &completion;
 	init_completion(&completion);
 
-	/* Perform sclp request. */
 	rc = sclp_add_request(request);
 	if (rc)
 		goto out;
 	wait_for_completion(&completion);
 
-	/* Check response. */
 	if (request->status != SCLP_REQ_DONE) {
 		pr_warn("sync request failed (cmd=0x%08x, status=0x%02x)\n",
 			cmd, request->status);
@@ -81,22 +94,15 @@ out:
 	return rc;
 }
 
-/*
- * CPU configuration related functions.
- */
-
-#define SCLP_CMDW_CONFIGURE_CPU		0x00110001
-#define SCLP_CMDW_DECONFIGURE_CPU	0x00100001
-
 int _sclp_get_core_info(struct sclp_core_info *info)
 {
-	int rc;
-	int length = test_facility(140) ? EXT_SCCB_READ_CPU : PAGE_SIZE;
 	struct read_cpu_info_sccb *sccb;
+	int rc, length;
 
 	if (!SCLP_HAS_CPU_INFO)
 		return -EOPNOTSUPP;
 
+	length = test_facility(140) ? EXT_SCCB_READ_CPU : PAGE_SIZE;
 	sccb = (void *)__get_free_pages(GFP_KERNEL | GFP_DMA | __GFP_ZERO, get_order(length));
 	if (!sccb)
 		return -ENOMEM;
@@ -114,14 +120,10 @@ int _sclp_get_core_info(struct sclp_core_info *info)
 	}
 	sclp_fill_core_info(info, sccb);
 out:
-	free_pages((unsigned long) sccb, get_order(length));
+	free_pages((unsigned long)sccb, get_order(length));
 	return rc;
 }
 
-struct cpu_configure_sccb {
-	struct sccb_header header;
-} __attribute__((packed, aligned(8)));
-
 static int do_core_configure(sclp_cmdw_t cmd)
 {
 	struct cpu_configure_sccb *sccb;
@@ -130,8 +132,8 @@ static int do_core_configure(sclp_cmdw_t cmd)
 	if (!SCLP_HAS_CPU_RECONFIG)
 		return -EOPNOTSUPP;
 	/*
-	 * This is not going to cross a page boundary since we force
-	 * kmalloc to have a minimum alignment of 8 bytes on s390.
+	 * Use kmalloc to have a minimum alignment of 8 bytes and ensure sccb
+	 * is not going to cross a page boundary.
 	 */
 	sccb = kzalloc(sizeof(*sccb), GFP_KERNEL | GFP_DMA);
 	if (!sccb)
@@ -165,394 +167,6 @@ int sclp_core_deconfigure(u8 core)
 	return do_core_configure(SCLP_CMDW_DECONFIGURE_CPU | core << 8);
 }
 
-#ifdef CONFIG_MEMORY_HOTPLUG
-
-static DEFINE_MUTEX(sclp_mem_mutex);
-static LIST_HEAD(sclp_mem_list);
-static u8 sclp_max_storage_id;
-static DECLARE_BITMAP(sclp_storage_ids, 256);
-
-struct memory_increment {
-	struct list_head list;
-	u16 rn;
-	int standby;
-};
-
-struct assign_storage_sccb {
-	struct sccb_header header;
-	u16 rn;
-} __packed;
-
-int arch_get_memory_phys_device(unsigned long start_pfn)
-{
-	if (!sclp.rzm)
-		return 0;
-	return PFN_PHYS(start_pfn) >> ilog2(sclp.rzm);
-}
-
-static unsigned long long rn2addr(u16 rn)
-{
-	return (unsigned long long) (rn - 1) * sclp.rzm;
-}
-
-static int do_assign_storage(sclp_cmdw_t cmd, u16 rn)
-{
-	struct assign_storage_sccb *sccb;
-	int rc;
-
-	sccb = (void *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
-	if (!sccb)
-		return -ENOMEM;
-	sccb->header.length = PAGE_SIZE;
-	sccb->rn = rn;
-	rc = sclp_sync_request_timeout(cmd, sccb, SCLP_QUEUE_INTERVAL);
-	if (rc)
-		goto out;
-	switch (sccb->header.response_code) {
-	case 0x0020:
-	case 0x0120:
-		break;
-	default:
-		pr_warn("assign storage failed (cmd=0x%08x, response=0x%04x, rn=0x%04x)\n",
-			cmd, sccb->header.response_code, rn);
-		rc = -EIO;
-		break;
-	}
-out:
-	free_page((unsigned long) sccb);
-	return rc;
-}
-
-static int sclp_assign_storage(u16 rn)
-{
-	unsigned long long start;
-	int rc;
-
-	rc = do_assign_storage(SCLP_CMDW_ASSIGN_STORAGE, rn);
-	if (rc)
-		return rc;
-	start = rn2addr(rn);
-	storage_key_init_range(start, start + sclp.rzm);
-	return 0;
-}
-
-static int sclp_unassign_storage(u16 rn)
-{
-	return do_assign_storage(SCLP_CMDW_UNASSIGN_STORAGE, rn);
-}
-
-struct attach_storage_sccb {
-	struct sccb_header header;
-	u16 :16;
-	u16 assigned;
-	u32 :32;
-	u32 entries[];
-} __packed;
-
-static int sclp_attach_storage(u8 id)
-{
-	struct attach_storage_sccb *sccb;
-	int rc;
-	int i;
-
-	sccb = (void *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
-	if (!sccb)
-		return -ENOMEM;
-	sccb->header.length = PAGE_SIZE;
-	sccb->header.function_code = 0x40;
-	rc = sclp_sync_request_timeout(0x00080001 | id << 8, sccb,
-				       SCLP_QUEUE_INTERVAL);
-	if (rc)
-		goto out;
-	switch (sccb->header.response_code) {
-	case 0x0020:
-		set_bit(id, sclp_storage_ids);
-		for (i = 0; i < sccb->assigned; i++) {
-			if (sccb->entries[i])
-				sclp_unassign_storage(sccb->entries[i] >> 16);
-		}
-		break;
-	default:
-		rc = -EIO;
-		break;
-	}
-out:
-	free_page((unsigned long) sccb);
-	return rc;
-}
-
-static int sclp_mem_change_state(unsigned long start, unsigned long size,
-				 int online)
-{
-	struct memory_increment *incr;
-	unsigned long long istart;
-	int rc = 0;
-
-	list_for_each_entry(incr, &sclp_mem_list, list) {
-		istart = rn2addr(incr->rn);
-		if (start + size - 1 < istart)
-			break;
-		if (start > istart + sclp.rzm - 1)
-			continue;
-		if (online)
-			rc |= sclp_assign_storage(incr->rn);
-		else
-			sclp_unassign_storage(incr->rn);
-		if (rc == 0)
-			incr->standby = online ? 0 : 1;
-	}
-	return rc ? -EIO : 0;
-}
-
-static bool contains_standby_increment(unsigned long start, unsigned long end)
-{
-	struct memory_increment *incr;
-	unsigned long istart;
-
-	list_for_each_entry(incr, &sclp_mem_list, list) {
-		istart = rn2addr(incr->rn);
-		if (end - 1 < istart)
-			continue;
-		if (start > istart + sclp.rzm - 1)
-			continue;
-		if (incr->standby)
-			return true;
-	}
-	return false;
-}
-
-static int sclp_mem_notifier(struct notifier_block *nb,
-			     unsigned long action, void *data)
-{
-	unsigned long start, size;
-	struct memory_notify *arg;
-	unsigned char id;
-	int rc = 0;
-
-	arg = data;
-	start = arg->start_pfn << PAGE_SHIFT;
-	size = arg->nr_pages << PAGE_SHIFT;
-	mutex_lock(&sclp_mem_mutex);
-	for_each_clear_bit(id, sclp_storage_ids, sclp_max_storage_id + 1)
-		sclp_attach_storage(id);
-	switch (action) {
-	case MEM_GOING_OFFLINE:
-		/*
-		 * We do not allow to set memory blocks offline that contain
-		 * standby memory. This is done to simplify the "memory online"
-		 * case.
-		 */
-		if (contains_standby_increment(start, start + size))
-			rc = -EPERM;
-		break;
-	case MEM_PREPARE_ONLINE:
-		/*
-		 * Access the altmap_start_pfn and altmap_nr_pages fields
-		 * within the struct memory_notify specifically when dealing
-		 * with only MEM_PREPARE_ONLINE/MEM_FINISH_OFFLINE notifiers.
-		 *
-		 * When altmap is in use, take the specified memory range
-		 * online, which includes the altmap.
-		 */
-		if (arg->altmap_nr_pages) {
-			start = PFN_PHYS(arg->altmap_start_pfn);
-			size += PFN_PHYS(arg->altmap_nr_pages);
-		}
-		rc = sclp_mem_change_state(start, size, 1);
-		if (rc || !arg->altmap_nr_pages)
-			break;
-		/*
-		 * Set CMMA state to nodat here, since the struct page memory
-		 * at the beginning of the memory block will not go through the
-		 * buddy allocator later.
-		 */
-		__arch_set_page_nodat((void *)__va(start), arg->altmap_nr_pages);
-		break;
-	case MEM_FINISH_OFFLINE:
-		/*
-		 * When altmap is in use, take the specified memory range
-		 * offline, which includes the altmap.
-		 */
-		if (arg->altmap_nr_pages) {
-			start = PFN_PHYS(arg->altmap_start_pfn);
-			size += PFN_PHYS(arg->altmap_nr_pages);
-		}
-		sclp_mem_change_state(start, size, 0);
-		break;
-	default:
-		break;
-	}
-	mutex_unlock(&sclp_mem_mutex);
-	return rc ? NOTIFY_BAD : NOTIFY_OK;
-}
-
-static struct notifier_block sclp_mem_nb = {
-	.notifier_call = sclp_mem_notifier,
-};
-
-static void __init align_to_block_size(unsigned long long *start,
-				       unsigned long long *size,
-				       unsigned long long alignment)
-{
-	unsigned long long start_align, size_align;
-
-	start_align = roundup(*start, alignment);
-	size_align = rounddown(*start + *size, alignment) - start_align;
-
-	pr_info("Standby memory at 0x%llx (%lluM of %lluM usable)\n",
-		*start, size_align >> 20, *size >> 20);
-	*start = start_align;
-	*size = size_align;
-}
-
-static void __init add_memory_merged(u16 rn)
-{
-	unsigned long long start, size, addr, block_size;
-	static u16 first_rn, num;
-
-	if (rn && first_rn && (first_rn + num == rn)) {
-		num++;
-		return;
-	}
-	if (!first_rn)
-		goto skip_add;
-	start = rn2addr(first_rn);
-	size = (unsigned long long) num * sclp.rzm;
-	if (start >= ident_map_size)
-		goto skip_add;
-	if (start + size > ident_map_size)
-		size = ident_map_size - start;
-	block_size = memory_block_size_bytes();
-	align_to_block_size(&start, &size, block_size);
-	if (!size)
-		goto skip_add;
-	for (addr = start; addr < start + size; addr += block_size)
-		add_memory(0, addr, block_size,
-			   cpu_has_edat1() ?
-			   MHP_MEMMAP_ON_MEMORY | MHP_OFFLINE_INACCESSIBLE : MHP_NONE);
-skip_add:
-	first_rn = rn;
-	num = 1;
-}
-
-static void __init sclp_add_standby_memory(void)
-{
-	struct memory_increment *incr;
-
-	list_for_each_entry(incr, &sclp_mem_list, list)
-		if (incr->standby)
-			add_memory_merged(incr->rn);
-	add_memory_merged(0);
-}
-
-static void __init insert_increment(u16 rn, int standby, int assigned)
-{
-	struct memory_increment *incr, *new_incr;
-	struct list_head *prev;
-	u16 last_rn;
-
-	new_incr = kzalloc(sizeof(*new_incr), GFP_KERNEL);
-	if (!new_incr)
-		return;
-	new_incr->rn = rn;
-	new_incr->standby = standby;
-	last_rn = 0;
-	prev = &sclp_mem_list;
-	list_for_each_entry(incr, &sclp_mem_list, list) {
-		if (assigned && incr->rn > rn)
-			break;
-		if (!assigned && incr->rn - last_rn > 1)
-			break;
-		last_rn = incr->rn;
-		prev = &incr->list;
-	}
-	if (!assigned)
-		new_incr->rn = last_rn + 1;
-	if (new_incr->rn > sclp.rnmax) {
-		kfree(new_incr);
-		return;
-	}
-	list_add(&new_incr->list, prev);
-}
-
-static int __init sclp_detect_standby_memory(void)
-{
-	struct read_storage_sccb *sccb;
-	int i, id, assigned, rc;
-
-	if (oldmem_data.start) /* No standby memory in kdump mode */
-		return 0;
-	if ((sclp.facilities & 0xe00000000000ULL) != 0xe00000000000ULL)
-		return 0;
-	rc = -ENOMEM;
-	sccb = (void *) __get_free_page(GFP_KERNEL | GFP_DMA);
-	if (!sccb)
-		goto out;
-	assigned = 0;
-	for (id = 0; id <= sclp_max_storage_id; id++) {
-		memset(sccb, 0, PAGE_SIZE);
-		sccb->header.length = PAGE_SIZE;
-		rc = sclp_sync_request(SCLP_CMDW_READ_STORAGE_INFO | id << 8, sccb);
-		if (rc)
-			goto out;
-		switch (sccb->header.response_code) {
-		case 0x0010:
-			set_bit(id, sclp_storage_ids);
-			for (i = 0; i < sccb->assigned; i++) {
-				if (!sccb->entries[i])
-					continue;
-				assigned++;
-				insert_increment(sccb->entries[i] >> 16, 0, 1);
-			}
-			break;
-		case 0x0310:
-			break;
-		case 0x0410:
-			for (i = 0; i < sccb->assigned; i++) {
-				if (!sccb->entries[i])
-					continue;
-				assigned++;
-				insert_increment(sccb->entries[i] >> 16, 1, 1);
-			}
-			break;
-		default:
-			rc = -EIO;
-			break;
-		}
-		if (!rc)
-			sclp_max_storage_id = sccb->max_id;
-	}
-	if (rc || list_empty(&sclp_mem_list))
-		goto out;
-	for (i = 1; i <= sclp.rnmax - assigned; i++)
-		insert_increment(0, 1, 0);
-	rc = register_memory_notifier(&sclp_mem_nb);
-	if (rc)
-		goto out;
-	sclp_add_standby_memory();
-out:
-	free_page((unsigned long) sccb);
-	return rc;
-}
-__initcall(sclp_detect_standby_memory);
-
-#endif /* CONFIG_MEMORY_HOTPLUG */
-
-/*
- * Channel path configuration related functions.
- */
-
-#define SCLP_CMDW_CONFIGURE_CHPATH		0x000f0001
-#define SCLP_CMDW_DECONFIGURE_CHPATH		0x000e0001
-#define SCLP_CMDW_READ_CHPATH_INFORMATION	0x00030001
-
-struct chp_cfg_sccb {
-	struct sccb_header header;
-	u8 ccm;
-	u8 reserved[6];
-	u8 cssid;
-} __attribute__((packed));
-
 static int do_chp_configure(sclp_cmdw_t cmd)
 {
 	struct chp_cfg_sccb *sccb;
@@ -560,8 +174,7 @@ static int do_chp_configure(sclp_cmdw_t cmd)
 
 	if (!SCLP_HAS_CHP_RECONFIG)
 		return -EOPNOTSUPP;
-	/* Prepare sccb. */
-	sccb = (struct chp_cfg_sccb *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
+	sccb = (struct chp_cfg_sccb *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
 	if (!sccb)
 		return -ENOMEM;
 	sccb->header.length = sizeof(*sccb);
@@ -581,7 +194,7 @@ static int do_chp_configure(sclp_cmdw_t cmd)
 		break;
 	}
 out:
-	free_page((unsigned long) sccb);
+	free_page((unsigned long)sccb);
 	return rc;
 }
 
@@ -609,16 +222,6 @@ int sclp_chp_deconfigure(struct chp_id chpid)
 	return do_chp_configure(SCLP_CMDW_DECONFIGURE_CHPATH | chpid.id << 8);
 }
 
-struct chp_info_sccb {
-	struct sccb_header header;
-	u8 recognized[SCLP_CHP_INFO_MASK_SIZE];
-	u8 standby[SCLP_CHP_INFO_MASK_SIZE];
-	u8 configured[SCLP_CHP_INFO_MASK_SIZE];
-	u8 ccm;
-	u8 reserved[6];
-	u8 cssid;
-} __attribute__((packed));
-
 /**
  * sclp_chp_read_info - perform read channel-path information sclp command
  * @info: resulting channel-path information data
@@ -634,8 +237,7 @@ int sclp_chp_read_info(struct sclp_chp_info *info)
 
 	if (!SCLP_HAS_CHP_INFO)
 		return -EOPNOTSUPP;
-	/* Prepare sccb. */
-	sccb = (struct chp_info_sccb *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
+	sccb = (struct chp_info_sccb *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
 	if (!sccb)
 		return -ENOMEM;
 	sccb->header.length = sizeof(*sccb);
@@ -652,6 +254,6 @@ int sclp_chp_read_info(struct sclp_chp_info *info)
 	memcpy(info->standby, sccb->standby, SCLP_CHP_INFO_MASK_SIZE);
 	memcpy(info->configured, sccb->configured, SCLP_CHP_INFO_MASK_SIZE);
 out:
-	free_page((unsigned long) sccb);
+	free_page((unsigned long)sccb);
 	return rc;
 }
diff --git a/drivers/s390/char/sclp_mem.c b/drivers/s390/char/sclp_mem.c
new file mode 100644
index 000000000000..27f49f5fd358
--- /dev/null
+++ b/drivers/s390/char/sclp_mem.c
@@ -0,0 +1,399 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Memory hotplug support via sclp
+ *
+ * Copyright IBM Corp. 2025
+ */
+
+#define KMSG_COMPONENT "sclp_mem"
+#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
+
+#include <linux/cpufeature.h>
+#include <linux/err.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/memory.h>
+#include <linux/memory_hotplug.h>
+#include <linux/mm.h>
+#include <linux/mmzone.h>
+#include <linux/slab.h>
+#include <asm/facility.h>
+#include <asm/page.h>
+#include <asm/page-states.h>
+#include <asm/sclp.h>
+
+#include "sclp.h"
+
+#define SCLP_CMDW_ASSIGN_STORAGE		0x000d0001
+#define SCLP_CMDW_UNASSIGN_STORAGE		0x000c0001
+
+static DEFINE_MUTEX(sclp_mem_mutex);
+static LIST_HEAD(sclp_mem_list);
+static u8 sclp_max_storage_id;
+static DECLARE_BITMAP(sclp_storage_ids, 256);
+
+struct memory_increment {
+	struct list_head list;
+	u16 rn;
+	int standby;
+};
+
+struct assign_storage_sccb {
+	struct sccb_header header;
+	u16 rn;
+} __packed;
+
+struct attach_storage_sccb {
+	struct sccb_header header;
+	u16 :16;
+	u16 assigned;
+	u32 :32;
+	u32 entries[];
+} __packed;
+
+int arch_get_memory_phys_device(unsigned long start_pfn)
+{
+	if (!sclp.rzm)
+		return 0;
+	return PFN_PHYS(start_pfn) >> ilog2(sclp.rzm);
+}
+
+static unsigned long rn2addr(u16 rn)
+{
+	return (unsigned long)(rn - 1) * sclp.rzm;
+}
+
+static int do_assign_storage(sclp_cmdw_t cmd, u16 rn)
+{
+	struct assign_storage_sccb *sccb;
+	int rc;
+
+	sccb = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
+	if (!sccb)
+		return -ENOMEM;
+	sccb->header.length = PAGE_SIZE;
+	sccb->rn = rn;
+	rc = sclp_sync_request_timeout(cmd, sccb, SCLP_QUEUE_INTERVAL);
+	if (rc)
+		goto out;
+	switch (sccb->header.response_code) {
+	case 0x0020:
+	case 0x0120:
+		break;
+	default:
+		pr_warn("assign storage failed (cmd=0x%08x, response=0x%04x, rn=0x%04x)\n",
+			cmd, sccb->header.response_code, rn);
+		rc = -EIO;
+		break;
+	}
+out:
+	free_page((unsigned long)sccb);
+	return rc;
+}
+
+static int sclp_assign_storage(u16 rn)
+{
+	unsigned long start;
+	int rc;
+
+	rc = do_assign_storage(SCLP_CMDW_ASSIGN_STORAGE, rn);
+	if (rc)
+		return rc;
+	start = rn2addr(rn);
+	storage_key_init_range(start, start + sclp.rzm);
+	return 0;
+}
+
+static int sclp_unassign_storage(u16 rn)
+{
+	return do_assign_storage(SCLP_CMDW_UNASSIGN_STORAGE, rn);
+}
+
+static int sclp_attach_storage(u8 id)
+{
+	struct attach_storage_sccb *sccb;
+	int rc, i;
+
+	sccb = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
+	if (!sccb)
+		return -ENOMEM;
+	sccb->header.length = PAGE_SIZE;
+	sccb->header.function_code = 0x40;
+	rc = sclp_sync_request_timeout(0x00080001 | id << 8, sccb,
+				       SCLP_QUEUE_INTERVAL);
+	if (rc)
+		goto out;
+	switch (sccb->header.response_code) {
+	case 0x0020:
+		set_bit(id, sclp_storage_ids);
+		for (i = 0; i < sccb->assigned; i++) {
+			if (sccb->entries[i])
+				sclp_unassign_storage(sccb->entries[i] >> 16);
+		}
+		break;
+	default:
+		rc = -EIO;
+		break;
+	}
+out:
+	free_page((unsigned long)sccb);
+	return rc;
+}
+
+static int sclp_mem_change_state(unsigned long start, unsigned long size,
+				 int online)
+{
+	struct memory_increment *incr;
+	unsigned long istart;
+	int rc = 0;
+
+	list_for_each_entry(incr, &sclp_mem_list, list) {
+		istart = rn2addr(incr->rn);
+		if (start + size - 1 < istart)
+			break;
+		if (start > istart + sclp.rzm - 1)
+			continue;
+		if (online)
+			rc |= sclp_assign_storage(incr->rn);
+		else
+			sclp_unassign_storage(incr->rn);
+		if (rc == 0)
+			incr->standby = online ? 0 : 1;
+	}
+	return rc ? -EIO : 0;
+}
+
+static bool contains_standby_increment(unsigned long start, unsigned long end)
+{
+	struct memory_increment *incr;
+	unsigned long istart;
+
+	list_for_each_entry(incr, &sclp_mem_list, list) {
+		istart = rn2addr(incr->rn);
+		if (end - 1 < istart)
+			continue;
+		if (start > istart + sclp.rzm - 1)
+			continue;
+		if (incr->standby)
+			return true;
+	}
+	return false;
+}
+
+static int sclp_mem_notifier(struct notifier_block *nb,
+			     unsigned long action, void *data)
+{
+	unsigned long start, size;
+	struct memory_notify *arg;
+	unsigned char id;
+	int rc = 0;
+
+	arg = data;
+	start = arg->start_pfn << PAGE_SHIFT;
+	size = arg->nr_pages << PAGE_SHIFT;
+	mutex_lock(&sclp_mem_mutex);
+	for_each_clear_bit(id, sclp_storage_ids, sclp_max_storage_id + 1)
+		sclp_attach_storage(id);
+	switch (action) {
+	case MEM_GOING_OFFLINE:
+		/*
+		 * Do not allow to set memory blocks offline that contain
+		 * standby memory. This is done to simplify the "memory online"
+		 * case.
+		 */
+		if (contains_standby_increment(start, start + size))
+			rc = -EPERM;
+		break;
+	case MEM_PREPARE_ONLINE:
+		/*
+		 * Access the altmap_start_pfn and altmap_nr_pages fields
+		 * within the struct memory_notify specifically when dealing
+		 * with only MEM_PREPARE_ONLINE/MEM_FINISH_OFFLINE notifiers.
+		 *
+		 * When altmap is in use, take the specified memory range
+		 * online, which includes the altmap.
+		 */
+		if (arg->altmap_nr_pages) {
+			start = PFN_PHYS(arg->altmap_start_pfn);
+			size += PFN_PHYS(arg->altmap_nr_pages);
+		}
+		rc = sclp_mem_change_state(start, size, 1);
+		if (rc || !arg->altmap_nr_pages)
+			break;
+		/*
+		 * Set CMMA state to nodat here, since the struct page memory
+		 * at the beginning of the memory block will not go through the
+		 * buddy allocator later.
+		 */
+		__arch_set_page_nodat((void *)__va(start), arg->altmap_nr_pages);
+		break;
+	case MEM_FINISH_OFFLINE:
+		/*
+		 * When altmap is in use, take the specified memory range
+		 * offline, which includes the altmap.
+		 */
+		if (arg->altmap_nr_pages) {
+			start = PFN_PHYS(arg->altmap_start_pfn);
+			size += PFN_PHYS(arg->altmap_nr_pages);
+		}
+		sclp_mem_change_state(start, size, 0);
+		break;
+	default:
+		break;
+	}
+	mutex_unlock(&sclp_mem_mutex);
+	return rc ? NOTIFY_BAD : NOTIFY_OK;
+}
+
+static struct notifier_block sclp_mem_nb = {
+	.notifier_call = sclp_mem_notifier,
+};
+
+static void __init align_to_block_size(unsigned long *start,
+				       unsigned long *size,
+				       unsigned long alignment)
+{
+	unsigned long start_align, size_align;
+
+	start_align = roundup(*start, alignment);
+	size_align = rounddown(*start + *size, alignment) - start_align;
+
+	pr_info("Standby memory at 0x%lx (%luM of %luM usable)\n",
+		*start, size_align >> 20, *size >> 20);
+	*start = start_align;
+	*size = size_align;
+}
+
+static void __init add_memory_merged(u16 rn)
+{
+	unsigned long start, size, addr, block_size;
+	static u16 first_rn, num;
+
+	if (rn && first_rn && (first_rn + num == rn)) {
+		num++;
+		return;
+	}
+	if (!first_rn)
+		goto skip_add;
+	start = rn2addr(first_rn);
+	size = (unsigned long)num * sclp.rzm;
+	if (start >= ident_map_size)
+		goto skip_add;
+	if (start + size > ident_map_size)
+		size = ident_map_size - start;
+	block_size = memory_block_size_bytes();
+	align_to_block_size(&start, &size, block_size);
+	if (!size)
+		goto skip_add;
+	for (addr = start; addr < start + size; addr += block_size) {
+		add_memory(0, addr, block_size,
+			   cpu_has_edat1() ?
+			   MHP_MEMMAP_ON_MEMORY | MHP_OFFLINE_INACCESSIBLE : MHP_NONE);
+	}
+skip_add:
+	first_rn = rn;
+	num = 1;
+}
+
+static void __init sclp_add_standby_memory(void)
+{
+	struct memory_increment *incr;
+
+	list_for_each_entry(incr, &sclp_mem_list, list) {
+		if (incr->standby)
+			add_memory_merged(incr->rn);
+	}
+	add_memory_merged(0);
+}
+
+static void __init insert_increment(u16 rn, int standby, int assigned)
+{
+	struct memory_increment *incr, *new_incr;
+	struct list_head *prev;
+	u16 last_rn;
+
+	new_incr = kzalloc(sizeof(*new_incr), GFP_KERNEL);
+	if (!new_incr)
+		return;
+	new_incr->rn = rn;
+	new_incr->standby = standby;
+	last_rn = 0;
+	prev = &sclp_mem_list;
+	list_for_each_entry(incr, &sclp_mem_list, list) {
+		if (assigned && incr->rn > rn)
+			break;
+		if (!assigned && incr->rn - last_rn > 1)
+			break;
+		last_rn = incr->rn;
+		prev = &incr->list;
+	}
+	if (!assigned)
+		new_incr->rn = last_rn + 1;
+	if (new_incr->rn > sclp.rnmax) {
+		kfree(new_incr);
+		return;
+	}
+	list_add(&new_incr->list, prev);
+}
+
+static int __init sclp_detect_standby_memory(void)
+{
+	struct read_storage_sccb *sccb;
+	int i, id, assigned, rc;
+
+	/* No standby memory in kdump mode */
+	if (oldmem_data.start)
+		return 0;
+	if ((sclp.facilities & 0xe00000000000UL) != 0xe00000000000UL)
+		return 0;
+	rc = -ENOMEM;
+	sccb = (void *)__get_free_page(GFP_KERNEL | GFP_DMA);
+	if (!sccb)
+		goto out;
+	assigned = 0;
+	for (id = 0; id <= sclp_max_storage_id; id++) {
+		memset(sccb, 0, PAGE_SIZE);
+		sccb->header.length = PAGE_SIZE;
+		rc = sclp_sync_request(SCLP_CMDW_READ_STORAGE_INFO | id << 8, sccb);
+		if (rc)
+			goto out;
+		switch (sccb->header.response_code) {
+		case 0x0010:
+			set_bit(id, sclp_storage_ids);
+			for (i = 0; i < sccb->assigned; i++) {
+				if (!sccb->entries[i])
+					continue;
+				assigned++;
+				insert_increment(sccb->entries[i] >> 16, 0, 1);
+			}
+			break;
+		case 0x0310:
+			break;
+		case 0x0410:
+			for (i = 0; i < sccb->assigned; i++) {
+				if (!sccb->entries[i])
+					continue;
+				assigned++;
+				insert_increment(sccb->entries[i] >> 16, 1, 1);
+			}
+			break;
+		default:
+			rc = -EIO;
+			break;
+		}
+		if (!rc)
+			sclp_max_storage_id = sccb->max_id;
+	}
+	if (rc || list_empty(&sclp_mem_list))
+		goto out;
+	for (i = 1; i <= sclp.rnmax - assigned; i++)
+		insert_increment(0, 1, 0);
+	rc = register_memory_notifier(&sclp_mem_nb);
+	if (rc)
+		goto out;
+	sclp_add_standby_memory();
+out:
+	free_page((unsigned long)sccb);
+	return rc;
+}
+__initcall(sclp_detect_standby_memory);
diff --git a/drivers/s390/char/tape_3590.c b/drivers/s390/char/tape_3590.c
index a1bafaf73f87..2a2931d303cb 100644
--- a/drivers/s390/char/tape_3590.c
+++ b/drivers/s390/char/tape_3590.c
@@ -1671,7 +1671,7 @@ tape_3590_init(void)
 
 	DBF_EVENT(3, "3590 init\n");
 
-	tape_3590_wq = alloc_workqueue("tape_3590", 0, 0);
+	tape_3590_wq = alloc_workqueue("tape_3590", WQ_PERCPU, 0);
 	if (!tape_3590_wq)
 		return -ENOMEM;