Merge tag 's390-6.1-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

Pull s390 updates from Vasily Gorbik:

 - Make use of the IBM z16 processor activity instrumentation facility
   extension to count neural network processor assist operations: add a
   new PMU device driver so that perf can make use of this.

 - Rework memcpy_real() to avoid DAT-off mode.

 - Rework absolute lowcore access code.

 - Various small fixes and improvements all over the code.

* tag 's390-6.1-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  s390/pci: remove unused bus_next field from struct zpci_dev
  s390/cio: remove unused ccw_device_force_console() declaration
  s390/pai: Add support for PAI Extension 1 NNPA counters
  s390/mm: fix no previous prototype warnings in maccess.c
  s390/mm: uninline copy_oldmem_kernel() function
  s390/mm,ptdump: add real memory copy page markers
  s390/mm: rework memcpy_real() to avoid DAT-off mode
  s390/dump: save IPL CPU registers once DAT is available
  s390/pci: convert high_memory to physical address
  s390/smp,ptdump: add absolute lowcore markers
  s390/smp: rework absolute lowcore access
  s390/smp: call smp_reinit_ipl_cpu() before scheduler is available
  s390/ptdump: add missing amode31 markers
  s390/mm: split lowcore pages with set_memory_4k()
  s390/mm: remove unused access parameter from do_fault_error()
  s390/delay: sync comment within __delay() with reality
  s390: move from strlcpy with unused retval to strscpy

arch/s390/boot/startup.c

@@ -10,11 +10,14 @@
 #include <asm/sclp.h>
 #include <asm/diag.h>
 #include <asm/uv.h>
+#include <asm/abs_lowcore.h>
 #include "decompressor.h"
 #include "boot.h"
 #include "uv.h"
 
 unsigned long __bootdata_preserved(__kaslr_offset);
+unsigned long __bootdata_preserved(__abs_lowcore);
+unsigned long __bootdata_preserved(__memcpy_real_area);
 unsigned long __bootdata(__amode31_base);
 unsigned long __bootdata_preserved(VMALLOC_START);
 unsigned long __bootdata_preserved(VMALLOC_END);
@@ -180,7 +183,10 @@ static void setup_kernel_memory_layout(void)
 	/* force vmalloc and modules below kasan shadow */
 	vmax = min(vmax, KASAN_SHADOW_START);
 #endif
-	MODULES_END = vmax;
+	__memcpy_real_area = round_down(vmax - PAGE_SIZE, PAGE_SIZE);
+	__abs_lowcore = round_down(__memcpy_real_area - ABS_LOWCORE_MAP_SIZE,
+				   sizeof(struct lowcore));
+	MODULES_END = round_down(__abs_lowcore, _SEGMENT_SIZE);
 	MODULES_VADDR = MODULES_END - MODULES_LEN;
 	VMALLOC_END = MODULES_VADDR;
 

arch/s390/include/asm/abs_lowcore.h

+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_S390_ABS_LOWCORE_H
+#define _ASM_S390_ABS_LOWCORE_H
+
+#include <asm/lowcore.h>
+
+#define ABS_LOWCORE_MAP_SIZE	(NR_CPUS * sizeof(struct lowcore))
+
+extern unsigned long __abs_lowcore;
+extern bool abs_lowcore_mapped;
+
+struct lowcore *get_abs_lowcore(unsigned long *flags);
+void put_abs_lowcore(struct lowcore *lc, unsigned long flags);
+int abs_lowcore_map(int cpu, struct lowcore *lc, bool alloc);
+void abs_lowcore_unmap(int cpu);
+
+#endif /* _ASM_S390_ABS_LOWCORE_H */

arch/s390/include/asm/ccwdev.h

@@ -214,7 +214,6 @@ extern struct ccw_device *ccw_device_create_console(struct ccw_driver *);
 extern void ccw_device_destroy_console(struct ccw_device *);
 extern int ccw_device_enable_console(struct ccw_device *);
 extern void ccw_device_wait_idle(struct ccw_device *);
-extern int ccw_device_force_console(struct ccw_device *);
 
 extern void *ccw_device_dma_zalloc(struct ccw_device *cdev, size_t size);
 extern void ccw_device_dma_free(struct ccw_device *cdev,

arch/s390/include/asm/ctl_reg.h

@@ -95,7 +95,8 @@ union ctlreg0 {
 					   Interruption-Filtering Override */
 		unsigned long	   : 3;
 		unsigned long ccc  : 1; /* Cryptography counter control */
-		unsigned long	   : 18;
+		unsigned long pec  : 1; /* PAI extension control */
+		unsigned long	   : 17;
 		unsigned long	   : 3;
 		unsigned long lap  : 1; /* Low-address-protection control */
 		unsigned long	   : 4;

arch/s390/include/asm/lowcore.h

@@ -203,7 +203,9 @@ struct lowcore {
 	__u8	pad_0x1400[0x1500-0x1400];	/* 0x1400 */
 	/* Cryptography-counter designation */
 	__u64	ccd;				/* 0x1500 */
-	__u8	pad_0x1508[0x1800-0x1508];	/* 0x1508 */
+	/* AI-extension counter designation */
+	__u64	aicd;				/* 0x1508 */
+	__u8	pad_0x1510[0x1800-0x1510];	/* 0x1510 */
 
 	/* Transaction abort diagnostic block */
 	struct pgm_tdb pgm_tdb;			/* 0x1800 */

arch/s390/include/asm/maccess.h

+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __ASM_S390_MACCESS_H
+#define __ASM_S390_MACCESS_H
+
+#include <linux/types.h>
+
+struct iov_iter;
+
+extern unsigned long __memcpy_real_area;
+void memcpy_real_init(void);
+size_t memcpy_real_iter(struct iov_iter *iter, unsigned long src, size_t count);
+int memcpy_real(void *dest, unsigned long src, size_t count);
+#ifdef CONFIG_CRASH_DUMP
+int copy_oldmem_kernel(void *dst, unsigned long src, size_t count);
+#endif
+
+#endif /* __ASM_S390_MACCESS_H */

arch/s390/include/asm/os_info.h

@@ -41,20 +41,6 @@ u32 os_info_csum(struct os_info *os_info);
 
 #ifdef CONFIG_CRASH_DUMP
 void *os_info_old_entry(int nr, unsigned long *size);
-size_t copy_oldmem_iter(struct iov_iter *iter, unsigned long src, size_t count);
-
-static inline int copy_oldmem_kernel(void *dst, unsigned long src, size_t count)
-{
-	struct iov_iter iter;
-	struct kvec kvec;
-
-	kvec.iov_base = dst;
-	kvec.iov_len = count;
-	iov_iter_kvec(&iter, WRITE, &kvec, 1, count);
-	if (copy_oldmem_iter(&iter, src, count) < count)
-		return -EFAULT;
-	return 0;
-}
 #else
 static inline void *os_info_old_entry(int nr, unsigned long *size)
 {

arch/s390/include/asm/pai.h

@@ -17,7 +17,9 @@ struct qpaci_info_block {
 	struct {
 		u64 : 8;
 		u64 num_cc : 8;	/* # of supported crypto counters */
-		u64 : 48;
+		u64 : 9;
+		u64 num_nnpa : 7;	/* # of supported NNPA counters */
+		u64 : 32;
 	};
 };
 
@@ -42,6 +44,8 @@ static inline int qpaci(struct qpaci_info_block *info)
 #define PAI_CRYPTO_BASE			0x1000	/* First event number */
 #define PAI_CRYPTO_MAXCTR		256	/* Max # of event counters */
 #define PAI_CRYPTO_KERNEL_OFFSET	2048
+#define PAI_NNPA_BASE			0x1800	/* First event number */
+#define PAI_NNPA_MAXCTR			128	/* Max # of event counters */
 
 DECLARE_STATIC_KEY_FALSE(pai_key);
 

arch/s390/include/asm/pci.h

@@ -117,7 +117,6 @@ struct zpci_bus {
 struct zpci_dev {
 	struct zpci_bus *zbus;
 	struct list_head entry;		/* list of all zpci_devices, needed for hotplug, etc. */
-	struct list_head bus_next;
 	struct kref kref;
 	struct hotplug_slot hotplug_slot;
 

arch/s390/include/asm/pgtable.h

@@ -1777,6 +1777,10 @@ static inline swp_entry_t __swp_entry(unsigned long type, unsigned long offset)
 
 extern int vmem_add_mapping(unsigned long start, unsigned long size);
 extern void vmem_remove_mapping(unsigned long start, unsigned long size);
+extern int __vmem_map_4k_page(unsigned long addr, unsigned long phys, pgprot_t prot, bool alloc);
+extern int vmem_map_4k_page(unsigned long addr, unsigned long phys, pgprot_t prot);
+extern void vmem_unmap_4k_page(unsigned long addr);
+extern pte_t *vmem_get_alloc_pte(unsigned long addr, bool alloc);
 extern int s390_enable_sie(void);
 extern int s390_enable_skey(void);
 extern void s390_reset_cmma(struct mm_struct *mm);

arch/s390/include/asm/processor.h

@@ -306,23 +306,6 @@ static __always_inline void __noreturn disabled_wait(void)
 
 #define ARCH_LOW_ADDRESS_LIMIT	0x7fffffffUL
 
-extern int memcpy_real(void *, unsigned long, size_t);
-extern void memcpy_absolute(void *, void *, size_t);
-
-#define put_abs_lowcore(member, x) do {					\
-	unsigned long __abs_address = offsetof(struct lowcore, member);	\
-	__typeof__(((struct lowcore *)0)->member) __tmp = (x);		\
-									\
-	memcpy_absolute(__va(__abs_address), &__tmp, sizeof(__tmp));	\
-} while (0)
-
-#define get_abs_lowcore(x, member) do {					\
-	unsigned long __abs_address = offsetof(struct lowcore, member);	\
-	__typeof__(((struct lowcore *)0)->member) *__ptr = &(x);	\
-									\
-	memcpy_absolute(__ptr, __va(__abs_address), sizeof(*__ptr));	\
-} while (0)
-
 extern int s390_isolate_bp(void);
 extern int s390_isolate_bp_guest(void);
 

arch/s390/include/asm/smp.h

@@ -30,7 +30,8 @@ extern void smp_emergency_stop(void);
 
 extern int smp_find_processor_id(u16 address);
 extern int smp_store_status(int cpu);
-extern void smp_save_dump_cpus(void);
+extern void smp_save_dump_ipl_cpu(void);
+extern void smp_save_dump_secondary_cpus(void);
 extern void smp_yield_cpu(int cpu);
 extern void smp_cpu_set_polarization(int cpu, int val);
 extern int smp_cpu_get_polarization(int cpu);
@@ -58,6 +59,7 @@ static inline void smp_cpus_done(unsigned int max_cpus)
 {
 }
 
+extern int smp_reinit_ipl_cpu(void);
 extern int smp_rescan_cpus(void);
 extern void __noreturn cpu_die(void);
 extern void __cpu_die(unsigned int cpu);

arch/s390/kernel/Makefile

@@ -40,7 +40,7 @@ obj-y	+= sysinfo.o lgr.o os_info.o machine_kexec.o
 obj-y	+= runtime_instr.o cache.o fpu.o dumpstack.o guarded_storage.o sthyi.o
 obj-y	+= entry.o reipl.o relocate_kernel.o kdebugfs.o alternative.o
 obj-y	+= nospec-branch.o ipl_vmparm.o machine_kexec_reloc.o unwind_bc.o
-obj-y	+= smp.o text_amode31.o stacktrace.o
+obj-y	+= smp.o text_amode31.o stacktrace.o abs_lowcore.o
 
 extra-y				+= head64.o vmlinux.lds
 
@@ -72,7 +72,7 @@ obj-$(CONFIG_IMA_SECURE_AND_OR_TRUSTED_BOOT)	+= ima_arch.o
 obj-$(CONFIG_PERF_EVENTS)	+= perf_event.o perf_cpum_cf_common.o
 obj-$(CONFIG_PERF_EVENTS)	+= perf_cpum_cf.o perf_cpum_sf.o
 obj-$(CONFIG_PERF_EVENTS)	+= perf_cpum_cf_events.o perf_regs.o
-obj-$(CONFIG_PERF_EVENTS)	+= perf_pai_crypto.o
+obj-$(CONFIG_PERF_EVENTS)	+= perf_pai_crypto.o perf_pai_ext.o
 
 obj-$(CONFIG_TRACEPOINTS)	+= trace.o
 obj-$(findstring y, $(CONFIG_PROTECTED_VIRTUALIZATION_GUEST) $(CONFIG_PGSTE))	+= uv.o

arch/s390/kernel/abs_lowcore.c

+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/pgtable.h>
+#include <asm/abs_lowcore.h>
+
+#define ABS_LOWCORE_UNMAPPED	1
+#define ABS_LOWCORE_LAP_ON	2
+#define ABS_LOWCORE_IRQS_ON	4
+
+unsigned long __bootdata_preserved(__abs_lowcore);
+bool __ro_after_init abs_lowcore_mapped;
+
+int abs_lowcore_map(int cpu, struct lowcore *lc, bool alloc)
+{
+	unsigned long addr = __abs_lowcore + (cpu * sizeof(struct lowcore));
+	unsigned long phys = __pa(lc);
+	int rc, i;
+
+	for (i = 0; i < LC_PAGES; i++) {
+		rc = __vmem_map_4k_page(addr, phys, PAGE_KERNEL, alloc);
+		if (rc) {
+			/*
+			 * Do not unmap allocated page tables in case the
+			 * allocation was not requested. In such a case the
+			 * request is expected coming from an atomic context,
+			 * while the unmap attempt might sleep.
+			 */
+			if (alloc) {
+				for (--i; i >= 0; i--) {
+					addr -= PAGE_SIZE;
+					vmem_unmap_4k_page(addr);
+				}
+			}
+			return rc;
+		}
+		addr += PAGE_SIZE;
+		phys += PAGE_SIZE;
+	}
+	return 0;
+}
+
+void abs_lowcore_unmap(int cpu)
+{
+	unsigned long addr = __abs_lowcore + (cpu * sizeof(struct lowcore));
+	int i;
+
+	for (i = 0; i < LC_PAGES; i++) {
+		vmem_unmap_4k_page(addr);
+		addr += PAGE_SIZE;
+	}
+}
+
+struct lowcore *get_abs_lowcore(unsigned long *flags)
+{
+	unsigned long irq_flags;
+	union ctlreg0 cr0;
+	int cpu;
+
+	*flags = 0;
+	cpu = get_cpu();
+	if (abs_lowcore_mapped) {
+		return ((struct lowcore *)__abs_lowcore) + cpu;
+	} else {
+		if (cpu != 0)
+			panic("Invalid unmapped absolute lowcore access\n");
+		local_irq_save(irq_flags);
+		if (!irqs_disabled_flags(irq_flags))
+			*flags |= ABS_LOWCORE_IRQS_ON;
+		__ctl_store(cr0.val, 0, 0);
+		if (cr0.lap) {
+			*flags |= ABS_LOWCORE_LAP_ON;
+			__ctl_clear_bit(0, 28);
+		}
+		*flags |= ABS_LOWCORE_UNMAPPED;
+		return lowcore_ptr[0];
+	}
+}
+
+void put_abs_lowcore(struct lowcore *lc, unsigned long flags)
+{
+	if (abs_lowcore_mapped) {
+		if (flags)
+			panic("Invalid mapped absolute lowcore release\n");
+	} else {
+		if (smp_processor_id() != 0)
+			panic("Invalid mapped absolute lowcore access\n");
+		if (!(flags & ABS_LOWCORE_UNMAPPED))
+			panic("Invalid unmapped absolute lowcore release\n");
+		if (flags & ABS_LOWCORE_LAP_ON)
+			__ctl_set_bit(0, 28);
+		if (flags & ABS_LOWCORE_IRQS_ON)
+			local_irq_enable();
+	}
+	put_cpu();
+}

arch/s390/kernel/crash_dump.c

@@ -21,6 +21,7 @@
 #include <asm/elf.h>
 #include <asm/ipl.h>
 #include <asm/sclp.h>
+#include <asm/maccess.h>
 
 #define PTR_ADD(x, y) (((char *) (x)) + ((unsigned long) (y)))
 #define PTR_SUB(x, y) (((char *) (x)) - ((unsigned long) (y)))
@@ -53,8 +54,6 @@ struct save_area {
 };
 
 static LIST_HEAD(dump_save_areas);
-static DEFINE_MUTEX(memcpy_real_mutex);
-static char memcpy_real_buf[PAGE_SIZE];
 
 /*
  * Allocate a save area
@@ -116,27 +115,7 @@ void __init save_area_add_vxrs(struct save_area *sa, __vector128 *vxrs)
 	memcpy(sa->vxrs_high, vxrs + 16, 16 * sizeof(__vector128));
 }
 
-static size_t copy_to_iter_real(struct iov_iter *iter, unsigned long src, size_t count)
-{
-	size_t len, copied, res = 0;
-
-	mutex_lock(&memcpy_real_mutex);
-	while (count) {
-		len = min(PAGE_SIZE, count);
-		if (memcpy_real(memcpy_real_buf, src, len))
-			break;
-		copied = copy_to_iter(memcpy_real_buf, len, iter);
-		count -= copied;
-		src += copied;
-		res += copied;
-		if (copied < len)
-			break;
-	}
-	mutex_unlock(&memcpy_real_mutex);
-	return res;
-}
-
-size_t copy_oldmem_iter(struct iov_iter *iter, unsigned long src, size_t count)
+static size_t copy_oldmem_iter(struct iov_iter *iter, unsigned long src, size_t count)
 {
 	size_t len, copied, res = 0;
 
@@ -156,7 +135,7 @@ size_t copy_oldmem_iter(struct iov_iter *iter, unsigned long src, size_t count)
 			} else {
 				len = count;
 			}
-			copied = copy_to_iter_real(iter, src, len);
+			copied = memcpy_real_iter(iter, src, len);
 		}
 		count -= copied;
 		src += copied;
@@ -167,6 +146,19 @@ size_t copy_oldmem_iter(struct iov_iter *iter, unsigned long src, size_t count)
 	return res;
 }
 
+int copy_oldmem_kernel(void *dst, unsigned long src, size_t count)
+{
+	struct iov_iter iter;
+	struct kvec kvec;
+
+	kvec.iov_base = dst;
+	kvec.iov_len = count;
+	iov_iter_kvec(&iter, WRITE, &kvec, 1, count);
+	if (copy_oldmem_iter(&iter, src, count) < count)
+		return -EFAULT;
+	return 0;
+}
+
 /*
  * Copy one page from "oldmem"
  */

arch/s390/kernel/debug.c

@@ -250,7 +250,7 @@ static debug_info_t *debug_info_alloc(const char *name, int pages_per_area,
 	rc->level	   = level;
 	rc->buf_size	   = buf_size;
 	rc->entry_size	   = sizeof(debug_entry_t) + buf_size;
-	strlcpy(rc->name, name, sizeof(rc->name));
+	strscpy(rc->name, name, sizeof(rc->name));
 	memset(rc->views, 0, DEBUG_MAX_VIEWS * sizeof(struct debug_view *));
 	memset(rc->debugfs_entries, 0, DEBUG_MAX_VIEWS * sizeof(struct dentry *));
 	refcount_set(&(rc->ref_count), 0);

arch/s390/kernel/early.c

@@ -267,7 +267,7 @@ char __bootdata(early_command_line)[COMMAND_LINE_SIZE];
 static void __init setup_boot_command_line(void)
 {
 	/* copy arch command line */
-	strlcpy(boot_command_line, early_command_line, COMMAND_LINE_SIZE);
+	strscpy(boot_command_line, early_command_line, COMMAND_LINE_SIZE);
 }
 
 static void __init check_image_bootable(void)

arch/s390/kernel/ipl.c

@@ -29,6 +29,7 @@
 #include <asm/sclp.h>
 #include <asm/checksum.h>
 #include <asm/debug.h>
+#include <asm/abs_lowcore.h>
 #include <asm/os_info.h>
 #include <asm/sections.h>
 #include <asm/boot_data.h>
@@ -1642,12 +1643,16 @@ static struct shutdown_action __refdata dump_action = {
 static void dump_reipl_run(struct shutdown_trigger *trigger)
 {
 	unsigned long ipib = (unsigned long) reipl_block_actual;
+	struct lowcore *abs_lc;
+	unsigned long flags;
 	unsigned int csum;
 
 	csum = (__force unsigned int)
 	       csum_partial(reipl_block_actual, reipl_block_actual->hdr.len, 0);
-	put_abs_lowcore(ipib, ipib);
-	put_abs_lowcore(ipib_checksum, csum);
+	abs_lc = get_abs_lowcore(&flags);
+	abs_lc->ipib = ipib;
+	abs_lc->ipib_checksum = csum;
+	put_abs_lowcore(abs_lc, flags);
 	dump_run(trigger);
 }
 

arch/s390/kernel/machine_kexec.c

@@ -21,6 +21,7 @@
 #include <asm/elf.h>
 #include <asm/asm-offsets.h>
 #include <asm/cacheflush.h>
+#include <asm/abs_lowcore.h>
 #include <asm/os_info.h>
 #include <asm/set_memory.h>
 #include <asm/stacktrace.h>
@@ -222,13 +223,18 @@ void machine_kexec_cleanup(struct kimage *image)
 
 void arch_crash_save_vmcoreinfo(void)
 {
+	struct lowcore *abs_lc;
+	unsigned long flags;
+
 	VMCOREINFO_SYMBOL(lowcore_ptr);
 	VMCOREINFO_SYMBOL(high_memory);
 	VMCOREINFO_LENGTH(lowcore_ptr, NR_CPUS);
 	vmcoreinfo_append_str("SAMODE31=%lx\n", __samode31);
 	vmcoreinfo_append_str("EAMODE31=%lx\n", __eamode31);
 	vmcoreinfo_append_str("KERNELOFFSET=%lx\n", kaslr_offset());
-	put_abs_lowcore(vmcore_info, paddr_vmcoreinfo_note());
+	abs_lc = get_abs_lowcore(&flags);
+	abs_lc->vmcore_info = paddr_vmcoreinfo_note();
+	put_abs_lowcore(abs_lc, flags);
 }
 
 void machine_shutdown(void)

arch/s390/kernel/os_info.c

@@ -13,8 +13,9 @@
 #include <linux/kernel.h>
 #include <linux/slab.h>
 #include <asm/checksum.h>
-#include <asm/lowcore.h>
+#include <asm/abs_lowcore.h>
 #include <asm/os_info.h>
+#include <asm/maccess.h>
 #include <asm/asm-offsets.h>
 
 /*
@@ -57,13 +58,16 @@ void os_info_entry_add(int nr, void *ptr, u64 size)
  */
 void __init os_info_init(void)
 {
-	void *ptr = &os_info;
+	struct lowcore *abs_lc;
+	unsigned long flags;
 
 	os_info.version_major = OS_INFO_VERSION_MAJOR;
 	os_info.version_minor = OS_INFO_VERSION_MINOR;
 	os_info.magic = OS_INFO_MAGIC;
 	os_info.csum = os_info_csum(&os_info);
-	put_abs_lowcore(os_info, __pa(ptr));
+	abs_lc = get_abs_lowcore(&flags);
+	abs_lc->os_info = __pa(&os_info);
+	put_abs_lowcore(abs_lc, flags);
 }
 
 #ifdef CONFIG_CRASH_DUMP

arch/s390/kernel/setup.c

@@ -58,7 +58,7 @@
 #include <asm/smp.h>
 #include <asm/mmu_context.h>
 #include <asm/cpcmd.h>
-#include <asm/lowcore.h>
+#include <asm/abs_lowcore.h>
 #include <asm/nmi.h>
 #include <asm/irq.h>
 #include <asm/page.h>
@@ -74,6 +74,7 @@
 #include <asm/alternative.h>
 #include <asm/nospec-branch.h>
 #include <asm/mem_detect.h>
+#include <asm/maccess.h>
 #include <asm/uv.h>
 #include <asm/asm-offsets.h>
 #include "entry.h"
@@ -395,6 +396,7 @@ void __init arch_call_rest_init(void)
 {
 	unsigned long stack;
 
+	smp_reinit_ipl_cpu();
 	stack = stack_alloc();
 	if (!stack)
 		panic("Couldn't allocate kernel stack");
@@ -411,8 +413,9 @@ void __init arch_call_rest_init(void)
 static void __init setup_lowcore_dat_off(void)
 {
 	unsigned long int_psw_mask = PSW_KERNEL_BITS;
+	struct lowcore *abs_lc, *lc;
 	unsigned long mcck_stack;
-	struct lowcore *lc;
+	unsigned long flags;
 
 	if (IS_ENABLED(CONFIG_KASAN))
 		int_psw_mask |= PSW_MASK_DAT;
@@ -474,12 +477,14 @@ static void __init setup_lowcore_dat_off(void)
 	lc->restart_data = 0;
 	lc->restart_source = -1U;
 
-	put_abs_lowcore(restart_stack, lc->restart_stack);
-	put_abs_lowcore(restart_fn, lc->restart_fn);
-	put_abs_lowcore(restart_data, lc->restart_data);
-	put_abs_lowcore(restart_source, lc->restart_source);
-	put_abs_lowcore(restart_psw, lc->restart_psw);
-	put_abs_lowcore(mcesad, lc->mcesad);
+	abs_lc = get_abs_lowcore(&flags);
+	abs_lc->restart_stack = lc->restart_stack;
+	abs_lc->restart_fn = lc->restart_fn;
+	abs_lc->restart_data = lc->restart_data;
+	abs_lc->restart_source = lc->restart_source;
+	abs_lc->restart_psw = lc->restart_psw;
+	abs_lc->mcesad = lc->mcesad;
+	put_abs_lowcore(abs_lc, flags);
 
 	mcck_stack = (unsigned long)memblock_alloc(THREAD_SIZE, THREAD_SIZE);
 	if (!mcck_stack)
@@ -500,8 +505,8 @@ static void __init setup_lowcore_dat_off(void)
 
 static void __init setup_lowcore_dat_on(void)
 {
-	struct lowcore *lc = lowcore_ptr[0];
-	int cr;
+	struct lowcore *abs_lc;
+	unsigned long flags;
 
 	__ctl_clear_bit(0, 28);
 	S390_lowcore.external_new_psw.mask |= PSW_MASK_DAT;
@@ -510,10 +515,15 @@ static void __init setup_lowcore_dat_on(void)
 	S390_lowcore.io_new_psw.mask |= PSW_MASK_DAT;
 	__ctl_set_bit(0, 28);
 	__ctl_store(S390_lowcore.cregs_save_area, 0, 15);
-	put_abs_lowcore(restart_flags, RESTART_FLAG_CTLREGS);
-	put_abs_lowcore(program_new_psw, lc->program_new_psw);
-	for (cr = 0; cr < ARRAY_SIZE(lc->cregs_save_area); cr++)
-		put_abs_lowcore(cregs_save_area[cr], lc->cregs_save_area[cr]);
+	if (abs_lowcore_map(0, lowcore_ptr[0], true))
+		panic("Couldn't setup absolute lowcore");
+	abs_lowcore_mapped = true;
+	abs_lc = get_abs_lowcore(&flags);
+	abs_lc->restart_flags = RESTART_FLAG_CTLREGS;
+	abs_lc->program_new_psw = S390_lowcore.program_new_psw;
+	memcpy(abs_lc->cregs_save_area, S390_lowcore.cregs_save_area,
+	       sizeof(abs_lc->cregs_save_area));
+	put_abs_lowcore(abs_lc, flags);
 }
 
 static struct resource code_resource = {
@@ -1019,10 +1029,10 @@ void __init setup_arch(char **cmdline_p)
 	reserve_crashkernel();
 #ifdef CONFIG_CRASH_DUMP
 	/*
-	 * Be aware that smp_save_dump_cpus() triggers a system reset.
+	 * Be aware that smp_save_dump_secondary_cpus() triggers a system reset.
 	 * Therefore CPU and device initialization should be done afterwards.
 	 */
-	smp_save_dump_cpus();
+	smp_save_dump_secondary_cpus();
 #endif
 
 	setup_resources();
@@ -1041,12 +1051,15 @@ void __init setup_arch(char **cmdline_p)
 	 * Create kernel page tables and switch to virtual addressing.
 	 */
         paging_init();
-
+	memcpy_real_init();
 	/*
 	 * After paging_init created the kernel page table, the new PSWs
 	 * in lowcore can now run with DAT enabled.
 	 */
 	setup_lowcore_dat_on();
+#ifdef CONFIG_CRASH_DUMP
+	smp_save_dump_ipl_cpu();
+#endif
 
         /* Setup default console */
 	conmode_default();

arch/s390/kernel/smp.c

@@ -45,7 +45,7 @@
 #include <asm/irq.h>
 #include <asm/tlbflush.h>
 #include <asm/vtimer.h>
-#include <asm/lowcore.h>
+#include <asm/abs_lowcore.h>
 #include <asm/sclp.h>
 #include <asm/debug.h>
 #include <asm/os_info.h>
@@ -55,6 +55,7 @@
 #include <asm/stacktrace.h>
 #include <asm/topology.h>
 #include <asm/vdso.h>
+#include <asm/maccess.h>
 #include "entry.h"
 
 enum {
@@ -212,10 +213,14 @@ static int pcpu_alloc_lowcore(struct pcpu *pcpu, int cpu)
 	lc->preempt_count = PREEMPT_DISABLED;
 	if (nmi_alloc_mcesa(&lc->mcesad))
 		goto out;
+	if (abs_lowcore_map(cpu, lc, true))
+		goto out_mcesa;
 	lowcore_ptr[cpu] = lc;
 	pcpu_sigp_retry(pcpu, SIGP_SET_PREFIX, __pa(lc));
 	return 0;
 
+out_mcesa:
+	nmi_free_mcesa(&lc->mcesad);
 out:
 	stack_free(mcck_stack);
 	stack_free(async_stack);
@@ -237,6 +242,7 @@ static void pcpu_free_lowcore(struct pcpu *pcpu)
 	mcck_stack = lc->mcck_stack - STACK_INIT_OFFSET;
 	pcpu_sigp_retry(pcpu, SIGP_SET_PREFIX, 0);
 	lowcore_ptr[cpu] = NULL;
+	abs_lowcore_unmap(cpu);
 	nmi_free_mcesa(&lc->mcesad);
 	stack_free(async_stack);
 	stack_free(mcck_stack);
@@ -315,9 +321,12 @@ static void pcpu_delegate(struct pcpu *pcpu,
 			  pcpu_delegate_fn *func,
 			  void *data, unsigned long stack)
 {
-	struct lowcore *lc = lowcore_ptr[pcpu - pcpu_devices];
-	unsigned int source_cpu = stap();
+	struct lowcore *lc, *abs_lc;
+	unsigned int source_cpu;
+	unsigned long flags;
 
+	lc = lowcore_ptr[pcpu - pcpu_devices];
+	source_cpu = stap();
 	__load_psw_mask(PSW_KERNEL_BITS | PSW_MASK_DAT);
 	if (pcpu->address == source_cpu) {
 		call_on_stack(2, stack, void, __pcpu_delegate,
@@ -332,10 +341,12 @@ static void pcpu_delegate(struct pcpu *pcpu,
 		lc->restart_data = (unsigned long)data;
 		lc->restart_source = source_cpu;
 	} else {
-		put_abs_lowcore(restart_stack, stack);
-		put_abs_lowcore(restart_fn, (unsigned long)func);
-		put_abs_lowcore(restart_data, (unsigned long)data);
-		put_abs_lowcore(restart_source, source_cpu);
+		abs_lc = get_abs_lowcore(&flags);
+		abs_lc->restart_stack = stack;
+		abs_lc->restart_fn = (unsigned long)func;
+		abs_lc->restart_data = (unsigned long)data;
+		abs_lc->restart_source = source_cpu;
+		put_abs_lowcore(abs_lc, flags);
 	}
 	__bpon();
 	asm volatile(
@@ -581,6 +592,8 @@ static DEFINE_SPINLOCK(ctl_lock);
 void smp_ctl_set_clear_bit(int cr, int bit, bool set)
 {
 	struct ec_creg_mask_parms parms = { .cr = cr, };
+	struct lowcore *abs_lc;
+	unsigned long flags;
 	u64 ctlreg;
 
 	if (set) {
@@ -591,9 +604,11 @@ void smp_ctl_set_clear_bit(int cr, int bit, bool set)
 		parms.andval = ~(1UL << bit);
 	}
 	spin_lock(&ctl_lock);
-	get_abs_lowcore(ctlreg, cregs_save_area[cr]);
+	abs_lc = get_abs_lowcore(&flags);
+	ctlreg = abs_lc->cregs_save_area[cr];
 	ctlreg = (ctlreg & parms.andval) | parms.orval;
-	put_abs_lowcore(cregs_save_area[cr], ctlreg);
+	abs_lc->cregs_save_area[cr] = ctlreg;
+	put_abs_lowcore(abs_lc, flags);
 	spin_unlock(&ctl_lock);
 	on_each_cpu(smp_ctl_bit_callback, &parms, 1);
 }
@@ -650,35 +665,36 @@ int smp_store_status(int cpu)
  *    This case does not exist for s390 anymore, setup_arch explicitly
  *    deactivates the elfcorehdr= kernel parameter
  */
-static __init void smp_save_cpu_vxrs(struct save_area *sa, u16 addr,
-				     bool is_boot_cpu, __vector128 *vxrs)
+static bool dump_available(void)
 {
-	if (is_boot_cpu)
-		vxrs = boot_cpu_vector_save_area;
-	else
-		__pcpu_sigp_relax(addr, SIGP_STORE_ADDITIONAL_STATUS, __pa(vxrs));
-	save_area_add_vxrs(sa, vxrs);
+	return oldmem_data.start || is_ipl_type_dump();
 }
 
-static __init void smp_save_cpu_regs(struct save_area *sa, u16 addr,
-				     bool is_boot_cpu, void *regs)
+void __init smp_save_dump_ipl_cpu(void)
 {
-	if (is_boot_cpu)
-		copy_oldmem_kernel(regs, __LC_FPREGS_SAVE_AREA, 512);
-	else
-		__pcpu_sigp_relax(addr, SIGP_STORE_STATUS_AT_ADDRESS, __pa(regs));
+	struct save_area *sa;
+	void *regs;
+
+	if (!dump_available())
+		return;
+	sa = save_area_alloc(true);
+	regs = memblock_alloc(512, 8);
+	if (!sa || !regs)
+		panic("could not allocate memory for boot CPU save area\n");
+	copy_oldmem_kernel(regs, __LC_FPREGS_SAVE_AREA, 512);
 	save_area_add_regs(sa, regs);
+	memblock_free(regs, 512);
+	if (MACHINE_HAS_VX)
+		save_area_add_vxrs(sa, boot_cpu_vector_save_area);
 }
 
-void __init smp_save_dump_cpus(void)
+void __init smp_save_dump_secondary_cpus(void)
 {
 	int addr, boot_cpu_addr, max_cpu_addr;
 	struct save_area *sa;
-	bool is_boot_cpu;
 	void *page;
 
-	if (!(oldmem_data.start || is_ipl_type_dump()))
-		/* No previous system present, normal boot. */
+	if (!dump_available())
 		return;
 	/* Allocate a page as dumping area for the store status sigps */
 	page = memblock_alloc_low(PAGE_SIZE, PAGE_SIZE);
@@ -691,26 +707,20 @@ void __init smp_save_dump_cpus(void)
 	boot_cpu_addr = stap();
 	max_cpu_addr = SCLP_MAX_CORES << sclp.mtid_prev;
 	for (addr = 0; addr <= max_cpu_addr; addr++) {
+		if (addr == boot_cpu_addr)
+			continue;
 		if (__pcpu_sigp_relax(addr, SIGP_SENSE, 0) ==
 		    SIGP_CC_NOT_OPERATIONAL)
 			continue;
-		is_boot_cpu = (addr == boot_cpu_addr);
-		/* Allocate save area */
-		sa = save_area_alloc(is_boot_cpu);
+		sa = save_area_alloc(false);
 		if (!sa)
 			panic("could not allocate memory for save area\n");
-		if (MACHINE_HAS_VX)
-			/* Get the vector registers */
-			smp_save_cpu_vxrs(sa, addr, is_boot_cpu, page);
-		/*
-		 * For a zfcp/nvme dump OLDMEM_BASE == NULL and the registers
-		 * of the boot CPU are stored in the HSA. To retrieve
-		 * these registers an SCLP request is required which is
-		 * done by drivers/s390/char/zcore.c:init_cpu_info()
-		 */
-		if (!is_boot_cpu || oldmem_data.start)
-			/* Get the CPU registers */
-			smp_save_cpu_regs(sa, addr, is_boot_cpu, page);
+		__pcpu_sigp_relax(addr, SIGP_STORE_STATUS_AT_ADDRESS, __pa(page));
+		save_area_add_regs(sa, page);
+		if (MACHINE_HAS_VX) {
+			__pcpu_sigp_relax(addr, SIGP_STORE_ADDITIONAL_STATUS, __pa(page));
+			save_area_add_vxrs(sa, page);
+		}
 	}
 	memblock_free(page, PAGE_SIZE);
 	diag_amode31_ops.diag308_reset();
@@ -1256,7 +1266,7 @@ static __always_inline void set_new_lowcore(struct lowcore *lc)
 		: "memory", "cc");
 }
 
-static int __init smp_reinit_ipl_cpu(void)
+int __init smp_reinit_ipl_cpu(void)
 {
 	unsigned long async_stack, nodat_stack, mcck_stack;
 	struct lowcore *lc, *lc_ipl;
@@ -1281,6 +1291,8 @@ static int __init smp_reinit_ipl_cpu(void)
 	__ctl_clear_bit(0, 28); /* disable lowcore protection */
 	S390_lowcore.mcesad = mcesad;
 	__ctl_load(cr0, 0, 0);
+	if (abs_lowcore_map(0, lc, false))
+		panic("Couldn't remap absolute lowcore");
 	lowcore_ptr[0] = lc;
 	local_mcck_enable();
 	local_irq_restore(flags);
@@ -1291,4 +1303,3 @@ static int __init smp_reinit_ipl_cpu(void)
 
 	return 0;
 }
-early_initcall(smp_reinit_ipl_cpu);

arch/s390/lib/delay.c

@@ -13,13 +13,10 @@
 
 void __delay(unsigned long loops)
 {
-        /*
-         * To end the bloody studid and useless discussion about the
-         * BogoMips number I took the liberty to define the __delay
-         * function in a way that that resulting BogoMips number will
-         * yield the megahertz number of the cpu. The important function
-         * is udelay and that is done using the tod clock. -- martin.
-         */
+	/*
+	 * Loop 'loops' times. Callers must not assume a specific
+	 * amount of time passes before this function returns.
+	 */
 	asm volatile("0: brct %0,0b" : : "d" ((loops/2) + 1));
 }
 EXPORT_SYMBOL(__delay);

arch/s390/mm/dump_pagetables.c

@@ -8,8 +8,10 @@
 #include <linux/kasan.h>
 #include <asm/ptdump.h>
 #include <asm/kasan.h>
+#include <asm/abs_lowcore.h>
 #include <asm/nospec-branch.h>
 #include <asm/sections.h>
+#include <asm/maccess.h>
 
 static unsigned long max_addr;
 
@@ -21,6 +23,8 @@ struct addr_marker {
 enum address_markers_idx {
 	IDENTITY_BEFORE_NR = 0,
 	IDENTITY_BEFORE_END_NR,
+	AMODE31_START_NR,
+	AMODE31_END_NR,
 	KERNEL_START_NR,
 	KERNEL_END_NR,
 #ifdef CONFIG_KFENCE
@@ -39,11 +43,17 @@ enum address_markers_idx {
 	VMALLOC_END_NR,
 	MODULES_NR,
 	MODULES_END_NR,
+	ABS_LOWCORE_NR,
+	ABS_LOWCORE_END_NR,
+	MEMCPY_REAL_NR,
+	MEMCPY_REAL_END_NR,
 };
 
 static struct addr_marker address_markers[] = {
 	[IDENTITY_BEFORE_NR]	= {0, "Identity Mapping Start"},
 	[IDENTITY_BEFORE_END_NR] = {(unsigned long)_stext, "Identity Mapping End"},
+	[AMODE31_START_NR]	= {0, "Amode31 Area Start"},
+	[AMODE31_END_NR]	= {0, "Amode31 Area End"},
 	[KERNEL_START_NR]	= {(unsigned long)_stext, "Kernel Image Start"},
 	[KERNEL_END_NR]		= {(unsigned long)_end, "Kernel Image End"},
 #ifdef CONFIG_KFENCE
@@ -62,6 +72,10 @@ static struct addr_marker address_markers[] = {
 	[VMALLOC_END_NR]	= {0, "vmalloc Area End"},
 	[MODULES_NR]		= {0, "Modules Area Start"},
 	[MODULES_END_NR]	= {0, "Modules Area End"},
+	[ABS_LOWCORE_NR]	= {0, "Lowcore Area Start"},
+	[ABS_LOWCORE_END_NR]	= {0, "Lowcore Area End"},
+	[MEMCPY_REAL_NR]	= {0, "Real Memory Copy Area Start"},
+	[MEMCPY_REAL_END_NR]	= {0, "Real Memory Copy Area End"},
 	{ -1, NULL }
 };
 
@@ -276,8 +290,14 @@ static int pt_dump_init(void)
 	max_addr = (S390_lowcore.kernel_asce & _REGION_ENTRY_TYPE_MASK) >> 2;
 	max_addr = 1UL << (max_addr * 11 + 31);
 	address_markers[IDENTITY_AFTER_END_NR].start_address = ident_map_size;
+	address_markers[AMODE31_START_NR].start_address = __samode31;
+	address_markers[AMODE31_END_NR].start_address = __eamode31;
 	address_markers[MODULES_NR].start_address = MODULES_VADDR;
 	address_markers[MODULES_END_NR].start_address = MODULES_END;
+	address_markers[ABS_LOWCORE_NR].start_address = __abs_lowcore;
+	address_markers[ABS_LOWCORE_END_NR].start_address = __abs_lowcore + ABS_LOWCORE_MAP_SIZE;
+	address_markers[MEMCPY_REAL_NR].start_address = __memcpy_real_area;
+	address_markers[MEMCPY_REAL_END_NR].start_address = __memcpy_real_area + PAGE_SIZE;
 	address_markers[VMEMMAP_NR].start_address = (unsigned long) vmemmap;
 	address_markers[VMEMMAP_END_NR].start_address = (unsigned long)vmemmap + vmemmap_size;
 	address_markers[VMALLOC_NR].start_address = VMALLOC_START;

arch/s390/mm/fault.c

@@ -268,8 +268,7 @@ static noinline void do_sigbus(struct pt_regs *regs)
 			(void __user *)(regs->int_parm_long & __FAIL_ADDR_MASK));
 }
 
-static noinline void do_fault_error(struct pt_regs *regs, int access,
-					vm_fault_t fault)
+static noinline void do_fault_error(struct pt_regs *regs, vm_fault_t fault)
 {
 	int si_code;
 
@@ -516,7 +515,7 @@ void do_protection_exception(struct pt_regs *regs)
 		fault = do_exception(regs, access);
 	}
 	if (unlikely(fault))
-		do_fault_error(regs, access, fault);
+		do_fault_error(regs, fault);
 }
 NOKPROBE_SYMBOL(do_protection_exception);
 
@@ -528,7 +527,7 @@ void do_dat_exception(struct pt_regs *regs)
 	access = VM_ACCESS_FLAGS;
 	fault = do_exception(regs, access);
 	if (unlikely(fault))
-		do_fault_error(regs, access, fault);
+		do_fault_error(regs, fault);
 }
 NOKPROBE_SYMBOL(do_dat_exception);
 
@@ -803,7 +802,7 @@ void do_secure_storage_access(struct pt_regs *regs)
 		addr = __gmap_translate(gmap, addr);
 		mmap_read_unlock(mm);
 		if (IS_ERR_VALUE(addr)) {
-			do_fault_error(regs, VM_ACCESS_FLAGS, VM_FAULT_BADMAP);
+			do_fault_error(regs, VM_FAULT_BADMAP);
 			break;
 		}
 		fallthrough;
@@ -813,7 +812,7 @@ void do_secure_storage_access(struct pt_regs *regs)
 		vma = find_vma(mm, addr);
 		if (!vma) {
 			mmap_read_unlock(mm);
-			do_fault_error(regs, VM_READ | VM_WRITE, VM_FAULT_BADMAP);
+			do_fault_error(regs, VM_FAULT_BADMAP);
 			break;
 		}
 		page = follow_page(vma, addr, FOLL_WRITE | FOLL_GET);
@@ -836,7 +835,7 @@ void do_secure_storage_access(struct pt_regs *regs)
 			BUG();
 		break;
 	default:
-		do_fault_error(regs, VM_READ | VM_WRITE, VM_FAULT_BADMAP);
+		do_fault_error(regs, VM_FAULT_BADMAP);
 		WARN_ON_ONCE(1);
 	}
 }
@@ -848,7 +847,7 @@ void do_non_secure_storage_access(struct pt_regs *regs)
 	struct gmap *gmap = (struct gmap *)S390_lowcore.gmap;
 
 	if (get_fault_type(regs) != GMAP_FAULT) {
-		do_fault_error(regs, VM_READ | VM_WRITE, VM_FAULT_BADMAP);
+		do_fault_error(regs, VM_FAULT_BADMAP);
 		WARN_ON_ONCE(1);
 		return;
 	}

arch/s390/mm/init.c

@@ -37,7 +37,7 @@
 #include <asm/kfence.h>
 #include <asm/ptdump.h>
 #include <asm/dma.h>
-#include <asm/lowcore.h>
+#include <asm/abs_lowcore.h>
 #include <asm/tlb.h>
 #include <asm/tlbflush.h>
 #include <asm/sections.h>

arch/s390/mm/maccess.c

@@ -12,10 +12,17 @@
 #include <linux/errno.h>
 #include <linux/gfp.h>
 #include <linux/cpu.h>
+#include <linux/uio.h>
 #include <asm/asm-extable.h>
 #include <asm/ctl_reg.h>
 #include <asm/io.h>
+#include <asm/abs_lowcore.h>
 #include <asm/stacktrace.h>
+#include <asm/maccess.h>
+
+unsigned long __bootdata_preserved(__memcpy_real_area);
+static __ro_after_init pte_t *memcpy_real_ptep;
+static DEFINE_MUTEX(memcpy_real_mutex);
 
 static notrace long s390_kernel_write_odd(void *dst, const void *src, size_t size)
 {
@@ -76,118 +83,72 @@ notrace void *s390_kernel_write(void *dst, const void *src, size_t size)
 	return dst;
 }
 
-static int __no_sanitize_address __memcpy_real(void *dest, void *src, size_t count)
+void __init memcpy_real_init(void)
 {
-	union register_pair _dst, _src;
-	int rc = -EFAULT;
-
-	_dst.even = (unsigned long) dest;
-	_dst.odd  = (unsigned long) count;
-	_src.even = (unsigned long) src;
-	_src.odd  = (unsigned long) count;
-	asm volatile (
-		"0:	mvcle	%[dst],%[src],0\n"
-		"1:	jo	0b\n"
-		"	lhi	%[rc],0\n"
-		"2:\n"
-		EX_TABLE(1b,2b)
-		: [rc] "+&d" (rc), [dst] "+&d" (_dst.pair), [src] "+&d" (_src.pair)
-		: : "cc", "memory");
-	return rc;
-}
-
-static unsigned long __no_sanitize_address _memcpy_real(unsigned long dest,
-							unsigned long src,
-							unsigned long count)
-{
-	int irqs_disabled, rc;
-	unsigned long flags;
-
-	if (!count)
-		return 0;
-	flags = arch_local_irq_save();
-	irqs_disabled = arch_irqs_disabled_flags(flags);
-	if (!irqs_disabled)
-		trace_hardirqs_off();
-	__arch_local_irq_stnsm(0xf8); // disable DAT
-	rc = __memcpy_real((void *) dest, (void *) src, (size_t) count);
-	if (flags & PSW_MASK_DAT)
-		__arch_local_irq_stosm(0x04); // enable DAT
-	if (!irqs_disabled)
-		trace_hardirqs_on();
-	__arch_local_irq_ssm(flags);
-	return rc;
+	memcpy_real_ptep = vmem_get_alloc_pte(__memcpy_real_area, true);
+	if (!memcpy_real_ptep)
+		panic("Couldn't setup memcpy real area");
 }
 
-/*
- * Copy memory in real mode (kernel to kernel)
- */
-int memcpy_real(void *dest, unsigned long src, size_t count)
+size_t memcpy_real_iter(struct iov_iter *iter, unsigned long src, size_t count)
 {
-	unsigned long _dest  = (unsigned long)dest;
-	unsigned long _src   = (unsigned long)src;
-	unsigned long _count = (unsigned long)count;
-	int rc;
-
-	if (S390_lowcore.nodat_stack != 0) {
-		preempt_disable();
-		rc = call_on_stack(3, S390_lowcore.nodat_stack,
-				   unsigned long, _memcpy_real,
-				   unsigned long, _dest,
-				   unsigned long, _src,
-				   unsigned long, _count);
-		preempt_enable();
-		return rc;
+	size_t len, copied, res = 0;
+	unsigned long phys, offset;
+	void *chunk;
+	pte_t pte;
+
+	while (count) {
+		phys = src & PAGE_MASK;
+		offset = src & ~PAGE_MASK;
+		chunk = (void *)(__memcpy_real_area + offset);
+		len = min(count, PAGE_SIZE - offset);
+		pte = mk_pte_phys(phys, PAGE_KERNEL_RO);
+
+		mutex_lock(&memcpy_real_mutex);
+		if (pte_val(pte) != pte_val(*memcpy_real_ptep)) {
+			__ptep_ipte(__memcpy_real_area, memcpy_real_ptep, 0, 0, IPTE_GLOBAL);
+			set_pte(memcpy_real_ptep, pte);
+		}
+		copied = copy_to_iter(chunk, len, iter);
+		mutex_unlock(&memcpy_real_mutex);
+
+		count -= copied;
+		src += copied;
+		res += copied;
+		if (copied < len)
+			break;
 	}
-	/*
-	 * This is a really early memcpy_real call, the stacks are
-	 * not set up yet. Just call _memcpy_real on the early boot
-	 * stack
-	 */
-	return _memcpy_real(_dest, _src, _count);
+	return res;
 }
 
-/*
- * Copy memory in absolute mode (kernel to kernel)
- */
-void memcpy_absolute(void *dest, void *src, size_t count)
+int memcpy_real(void *dest, unsigned long src, size_t count)
 {
-	unsigned long cr0, flags, prefix;
-
-	flags = arch_local_irq_save();
-	__ctl_store(cr0, 0, 0);
-	__ctl_clear_bit(0, 28); /* disable lowcore protection */
-	prefix = store_prefix();
-	if (prefix) {
-		local_mcck_disable();
-		set_prefix(0);
-		memcpy(dest, src, count);
-		set_prefix(prefix);
-		local_mcck_enable();
-	} else {
-		memcpy(dest, src, count);
-	}
-	__ctl_load(cr0, 0, 0);
-	arch_local_irq_restore(flags);
+	struct iov_iter iter;
+	struct kvec kvec;
+
+	kvec.iov_base = dest;
+	kvec.iov_len = count;
+	iov_iter_kvec(&iter, WRITE, &kvec, 1, count);
+	if (memcpy_real_iter(&iter, src, count) < count)
+		return -EFAULT;
+	return 0;
 }
 
 /*
- * Check if physical address is within prefix or zero page
+ * Find CPU that owns swapped prefix page
  */
-static int is_swapped(phys_addr_t addr)
+static int get_swapped_owner(phys_addr_t addr)
 {
 	phys_addr_t lc;
 	int cpu;
 
-	if (addr < sizeof(struct lowcore))
-		return 1;
 	for_each_online_cpu(cpu) {
 		lc = virt_to_phys(lowcore_ptr[cpu]);
 		if (addr > lc + sizeof(struct lowcore) - 1 || addr < lc)
 			continue;
-		return 1;
+		return cpu;
 	}
-	return 0;
+	return -1;
 }
 
 /*
@@ -200,17 +161,35 @@ void *xlate_dev_mem_ptr(phys_addr_t addr)
 {
 	void *ptr = phys_to_virt(addr);
 	void *bounce = ptr;
+	struct lowcore *abs_lc;
+	unsigned long flags;
 	unsigned long size;
+	int this_cpu, cpu;
 
 	cpus_read_lock();
-	preempt_disable();
-	if (is_swapped(addr)) {
-		size = PAGE_SIZE - (addr & ~PAGE_MASK);
-		bounce = (void *) __get_free_page(GFP_ATOMIC);
-		if (bounce)
-			memcpy_absolute(bounce, ptr, size);
+	this_cpu = get_cpu();
+	if (addr >= sizeof(struct lowcore)) {
+		cpu = get_swapped_owner(addr);
+		if (cpu < 0)
+			goto out;
+	}
+	bounce = (void *)__get_free_page(GFP_ATOMIC);
+	if (!bounce)
+		goto out;
+	size = PAGE_SIZE - (addr & ~PAGE_MASK);
+	if (addr < sizeof(struct lowcore)) {
+		abs_lc = get_abs_lowcore(&flags);
+		ptr = (void *)abs_lc + addr;
+		memcpy(bounce, ptr, size);
+		put_abs_lowcore(abs_lc, flags);
+	} else if (cpu == this_cpu) {
+		ptr = (void *)(addr - virt_to_phys(lowcore_ptr[cpu]));
+		memcpy(bounce, ptr, size);
+	} else {
+		memcpy(bounce, ptr, size);
 	}
-	preempt_enable();
+out:
+	put_cpu();
 	cpus_read_unlock();
 	return bounce;
 }

arch/s390/mm/vmem.c

@@ -240,7 +240,7 @@ static int __ref modify_pmd_table(pud_t *pud, unsigned long addr,
 		} else if (pmd_none(*pmd)) {
 			if (IS_ALIGNED(addr, PMD_SIZE) &&
 			    IS_ALIGNED(next, PMD_SIZE) &&
-			    MACHINE_HAS_EDAT1 && addr && direct &&
+			    MACHINE_HAS_EDAT1 && direct &&
 			    !debug_pagealloc_enabled()) {
 				set_pmd(pmd, __pmd(__pa(addr) | prot));
 				pages++;
@@ -336,7 +336,7 @@ static int modify_pud_table(p4d_t *p4d, unsigned long addr, unsigned long end,
 		} else if (pud_none(*pud)) {
 			if (IS_ALIGNED(addr, PUD_SIZE) &&
 			    IS_ALIGNED(next, PUD_SIZE) &&
-			    MACHINE_HAS_EDAT2 && addr && direct &&
+			    MACHINE_HAS_EDAT2 && direct &&
 			    !debug_pagealloc_enabled()) {
 				set_pud(pud, __pud(__pa(addr) | prot));
 				pages++;
@@ -560,6 +560,103 @@ int vmem_add_mapping(unsigned long start, unsigned long size)
 	return ret;
 }
 
+/*
+ * Allocate new or return existing page-table entry, but do not map it
+ * to any physical address. If missing, allocate segment- and region-
+ * table entries along. Meeting a large segment- or region-table entry
+ * while traversing is an error, since the function is expected to be
+ * called against virtual regions reserverd for 4KB mappings only.
+ */
+pte_t *vmem_get_alloc_pte(unsigned long addr, bool alloc)
+{
+	pte_t *ptep = NULL;
+	pgd_t *pgd;
+	p4d_t *p4d;
+	pud_t *pud;
+	pmd_t *pmd;
+	pte_t *pte;
+
+	pgd = pgd_offset_k(addr);
+	if (pgd_none(*pgd)) {
+		if (!alloc)
+			goto out;
+		p4d = vmem_crst_alloc(_REGION2_ENTRY_EMPTY);
+		if (!p4d)
+			goto out;
+		pgd_populate(&init_mm, pgd, p4d);
+	}
+	p4d = p4d_offset(pgd, addr);
+	if (p4d_none(*p4d)) {
+		if (!alloc)
+			goto out;
+		pud = vmem_crst_alloc(_REGION3_ENTRY_EMPTY);
+		if (!pud)
+			goto out;
+		p4d_populate(&init_mm, p4d, pud);
+	}
+	pud = pud_offset(p4d, addr);
+	if (pud_none(*pud)) {
+		if (!alloc)
+			goto out;
+		pmd = vmem_crst_alloc(_SEGMENT_ENTRY_EMPTY);
+		if (!pmd)
+			goto out;
+		pud_populate(&init_mm, pud, pmd);
+	} else if (WARN_ON_ONCE(pud_large(*pud))) {
+		goto out;
+	}
+	pmd = pmd_offset(pud, addr);
+	if (pmd_none(*pmd)) {
+		if (!alloc)
+			goto out;
+		pte = vmem_pte_alloc();
+		if (!pte)
+			goto out;
+		pmd_populate(&init_mm, pmd, pte);
+	} else if (WARN_ON_ONCE(pmd_large(*pmd))) {
+		goto out;
+	}
+	ptep = pte_offset_kernel(pmd, addr);
+out:
+	return ptep;
+}
+
+int __vmem_map_4k_page(unsigned long addr, unsigned long phys, pgprot_t prot, bool alloc)
+{
+	pte_t *ptep, pte;
+
+	if (!IS_ALIGNED(addr, PAGE_SIZE))
+		return -EINVAL;
+	ptep = vmem_get_alloc_pte(addr, alloc);
+	if (!ptep)
+		return -ENOMEM;
+	__ptep_ipte(addr, ptep, 0, 0, IPTE_GLOBAL);
+	pte = mk_pte_phys(phys, prot);
+	set_pte(ptep, pte);
+	return 0;
+}
+
+int vmem_map_4k_page(unsigned long addr, unsigned long phys, pgprot_t prot)
+{
+	int rc;
+
+	mutex_lock(&vmem_mutex);
+	rc = __vmem_map_4k_page(addr, phys, prot, true);
+	mutex_unlock(&vmem_mutex);
+	return rc;
+}
+
+void vmem_unmap_4k_page(unsigned long addr)
+{
+	pte_t *ptep;
+
+	mutex_lock(&vmem_mutex);
+	ptep = virt_to_kpte(addr);
+	__ptep_ipte(addr, ptep, 0, 0, IPTE_GLOBAL);
+	pte_clear(&init_mm, addr, ptep);
+	mutex_unlock(&vmem_mutex);
+}
+
 /*
  * map whole physical memory to virtual memory (identity mapping)
  * we reserve enough space in the vmalloc area for vmemmap to hotplug
@@ -584,6 +681,9 @@ void __init vmem_map_init(void)
 	__set_memory(__stext_amode31, (__etext_amode31 - __stext_amode31) >> PAGE_SHIFT,
 		     SET_MEMORY_RO | SET_MEMORY_X);
 
+	/* lowcore requires 4k mapping for real addresses / prefixing */
+	set_memory_4k(0, LC_PAGES);
+
 	/* lowcore must be executable for LPSWE */
 	if (!static_key_enabled(&cpu_has_bear))
 		set_memory_x(0, 1);

arch/s390/pci/pci_dma.c

@@ -666,7 +666,7 @@ static int __init dma_alloc_cpu_table_caches(void)
 
 int __init zpci_dma_init(void)
 {
-	s390_iommu_aperture = (u64)high_memory;
+	s390_iommu_aperture = (u64)virt_to_phys(high_memory);
 	if (!s390_iommu_aperture_factor)
 		s390_iommu_aperture = ULONG_MAX;
 	else

drivers/s390/block/dasd_devmap.c

@@ -426,7 +426,7 @@ dasd_add_busid(const char *bus_id, int features)
 	if (!devmap) {
 		/* This bus_id is new. */
 		new->devindex = dasd_max_devindex++;
-		strlcpy(new->bus_id, bus_id, DASD_BUS_ID_SIZE);
+		strscpy(new->bus_id, bus_id, DASD_BUS_ID_SIZE);
 		new->features = features;
 		new->device = NULL;
 		list_add(&new->list, &dasd_hashlists[hash]);

drivers/s390/block/dasd_eer.c

@@ -313,7 +313,7 @@ static void dasd_eer_write_standard_trigger(struct dasd_device *device,
 	ktime_get_real_ts64(&ts);
 	header.tv_sec = ts.tv_sec;
 	header.tv_usec = ts.tv_nsec / NSEC_PER_USEC;
-	strlcpy(header.busid, dev_name(&device->cdev->dev),
+	strscpy(header.busid, dev_name(&device->cdev->dev),
 		DASD_EER_BUSID_SIZE);
 
 	spin_lock_irqsave(&bufferlock, flags);
@@ -356,7 +356,7 @@ static void dasd_eer_write_snss_trigger(struct dasd_device *device,
 	ktime_get_real_ts64(&ts);
 	header.tv_sec = ts.tv_sec;
 	header.tv_usec = ts.tv_nsec / NSEC_PER_USEC;
-	strlcpy(header.busid, dev_name(&device->cdev->dev),
+	strscpy(header.busid, dev_name(&device->cdev->dev),
 		DASD_EER_BUSID_SIZE);
 
 	spin_lock_irqsave(&bufferlock, flags);

drivers/s390/block/dcssblk.c

@@ -614,7 +614,7 @@ dcssblk_add_store(struct device *dev, struct device_attribute *attr, const char
 		rc = -ENAMETOOLONG;
 		goto seg_list_del;
 	}
-	strlcpy(local_buf, buf, i + 1);
+	strscpy(local_buf, buf, i + 1);
 	dev_info->num_of_segments = num_of_segments;
 	rc = dcssblk_is_continuous(dev_info);
 	if (rc < 0)

drivers/s390/char/hmcdrv_cache.c

@@ -154,7 +154,7 @@ static ssize_t hmcdrv_cache_do(const struct hmcdrv_ftp_cmdspec *ftp,
 		/* cache some file info (FTP command, file name and file
 		 * size) unconditionally
 		 */
-		strlcpy(hmcdrv_cache_file.fname, ftp->fname,
+		strscpy(hmcdrv_cache_file.fname, ftp->fname,
 			HMCDRV_FTP_FIDENT_MAX);
 		hmcdrv_cache_file.id = ftp->id;
 		pr_debug("caching cmd %d, file size %zu for '%s'\n",

drivers/s390/char/tape_class.c

@@ -54,10 +54,10 @@ struct tape_class_device *register_tape_dev(
 	if (!tcd)
 		return ERR_PTR(-ENOMEM);
 
-	strlcpy(tcd->device_name, device_name, TAPECLASS_NAME_LEN);
+	strscpy(tcd->device_name, device_name, TAPECLASS_NAME_LEN);
 	for (s = strchr(tcd->device_name, '/'); s; s = strchr(s, '/'))
 		*s = '!';
-	strlcpy(tcd->mode_name, mode_name, TAPECLASS_NAME_LEN);
+	strscpy(tcd->mode_name, mode_name, TAPECLASS_NAME_LEN);
 	for (s = strchr(tcd->mode_name, '/'); s; s = strchr(s, '/'))
 		*s = '!';
 

drivers/s390/char/zcore.c

@@ -30,6 +30,7 @@
 #include <asm/checksum.h>
 #include <asm/os_info.h>
 #include <asm/switch_to.h>
+#include <asm/maccess.h>
 #include "sclp.h"
 
 #define TRACE(x...) debug_sprintf_event(zcore_dbf, 1, x)

drivers/s390/cio/qdio_debug.c

@@ -87,7 +87,7 @@ int qdio_allocate_dbf(struct qdio_irq *irq_ptr)
 			debug_unregister(irq_ptr->debug_area);
 			return -ENOMEM;
 		}
-		strlcpy(new_entry->dbf_name, text, QDIO_DBF_NAME_LEN);
+		strscpy(new_entry->dbf_name, text, QDIO_DBF_NAME_LEN);
 		new_entry->dbf_info = irq_ptr->debug_area;
 		mutex_lock(&qdio_dbf_list_mutex);
 		list_add(&new_entry->dbf_list, &qdio_dbf_list);

drivers/s390/net/ctcm_main.c

@@ -1566,7 +1566,7 @@ static int ctcm_new_device(struct ccwgroup_device *cgdev)
 		goto out_dev;
 	}
 
-	strlcpy(priv->fsm->name, dev->name, sizeof(priv->fsm->name));
+	strscpy(priv->fsm->name, dev->name, sizeof(priv->fsm->name));
 
 	dev_info(&dev->dev,
 		"setup OK : r/w = %s/%s, protocol : %d\n",

drivers/s390/net/fsm.c

@@ -28,7 +28,7 @@ init_fsm(char *name, const char **state_names, const char **event_names, int nr_
 			"fsm(%s): init_fsm: Couldn't alloc instance\n", name);
 		return NULL;
 	}
-	strlcpy(this->name, name, sizeof(this->name));
+	strscpy(this->name, name, sizeof(this->name));
 	init_waitqueue_head(&this->wait_q);
 
 	f = kzalloc(sizeof(fsm), order);

drivers/s390/net/qeth_ethtool.c

@@ -188,9 +188,9 @@ static void qeth_get_drvinfo(struct net_device *dev,
 {
 	struct qeth_card *card = dev->ml_priv;
 
-	strlcpy(info->driver, IS_LAYER2(card) ? "qeth_l2" : "qeth_l3",
+	strscpy(info->driver, IS_LAYER2(card) ? "qeth_l2" : "qeth_l3",
 		sizeof(info->driver));
-	strlcpy(info->fw_version, card->info.mcl_level,
+	strscpy(info->fw_version, card->info.mcl_level,
 		sizeof(info->fw_version));
 	snprintf(info->bus_info, sizeof(info->bus_info), "%s/%s/%s",
 		 CARD_RDEV_ID(card), CARD_WDEV_ID(card), CARD_DDEV_ID(card));

drivers/s390/scsi/zfcp_aux.c

@@ -103,7 +103,7 @@ static void __init zfcp_init_device_setup(char *devstr)
 	token = strsep(&str, ",");
 	if (!token || strlen(token) >= ZFCP_BUS_ID_SIZE)
 		goto err_out;
-	strlcpy(busid, token, ZFCP_BUS_ID_SIZE);
+	strscpy(busid, token, ZFCP_BUS_ID_SIZE);
 
 	token = strsep(&str, ",");
 	if (!token || kstrtoull(token, 0, (unsigned long long *) &wwpn))

drivers/s390/scsi/zfcp_fc.c

@@ -885,7 +885,7 @@ static int zfcp_fc_gspn(struct zfcp_adapter *adapter,
 			 dev_name(&adapter->ccw_device->dev),
 			 init_utsname()->nodename);
 	else
-		strlcpy(fc_host_symbolic_name(adapter->scsi_host),
+		strscpy(fc_host_symbolic_name(adapter->scsi_host),
 			gspn_rsp->gspn.fp_name, FC_SYMBOLIC_NAME_SIZE);
 
 	return 0;