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

Pull s390 updates from Alexander Gordeev:

 - Rework copy_oldmem_page() callback to take an iov_iter.

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

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

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

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

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

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

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

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

 - Minor boot code cleanups.

 - Grammar and typo fixes to hmcdrv and tape drivers.

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

27 files changed, 138 insertions, 188 deletions

diff --git a/arch/s390/boot/startup.c b/arch/s390/boot/startup.c
index 863e6bcaa5a1..bc48fe82d949 100644
--- a/arch/s390/boot/startup.c
+++ b/arch/s390/boot/startup.c
@@ -152,6 +152,7 @@ static void setup_kernel_memory_layout(void)
 	unsigned long vmemmap_start;
 	unsigned long rte_size;
 	unsigned long pages;
+	unsigned long vmax;
 
 	pages = ident_map_size / PAGE_SIZE;
 	/* vmemmap contains a multiple of PAGES_PER_SECTION struct pages */
@@ -163,10 +164,10 @@ static void setup_kernel_memory_layout(void)
 	    vmalloc_size > _REGION2_SIZE ||
 	    vmemmap_start + vmemmap_size + vmalloc_size + MODULES_LEN >
 		    _REGION2_SIZE) {
-		MODULES_END = _REGION1_SIZE;
+		vmax = _REGION1_SIZE;
 		rte_size = _REGION2_SIZE;
 	} else {
-		MODULES_END = _REGION2_SIZE;
+		vmax = _REGION2_SIZE;
 		rte_size = _REGION3_SIZE;
 	}
 	/*
@@ -174,11 +175,12 @@ static void setup_kernel_memory_layout(void)
 	 * secure storage limit, so that any vmalloc allocation
 	 * we do could be used to back secure guest storage.
 	 */
-	adjust_to_uv_max(&MODULES_END);
+	vmax = adjust_to_uv_max(vmax);
 #ifdef CONFIG_KASAN
 	/* force vmalloc and modules below kasan shadow */
-	MODULES_END = min(MODULES_END, KASAN_SHADOW_START);
+	vmax = min(vmax, KASAN_SHADOW_START);
 #endif
+	MODULES_END = vmax;
 	MODULES_VADDR = MODULES_END - MODULES_LEN;
 	VMALLOC_END = MODULES_VADDR;
 
diff --git a/arch/s390/boot/uv.c b/arch/s390/boot/uv.c
index a5fa667160b2..0a077c0a2056 100644
--- a/arch/s390/boot/uv.c
+++ b/arch/s390/boot/uv.c
@@ -57,10 +57,11 @@ void uv_query_info(void)
 }
 
 #if IS_ENABLED(CONFIG_KVM)
-void adjust_to_uv_max(unsigned long *vmax)
+unsigned long adjust_to_uv_max(unsigned long limit)
 {
 	if (is_prot_virt_host() && uv_info.max_sec_stor_addr)
-		*vmax = min_t(unsigned long, *vmax, uv_info.max_sec_stor_addr);
+		limit = min_t(unsigned long, limit, uv_info.max_sec_stor_addr);
+	return limit;
 }
 
 static int is_prot_virt_host_capable(void)
diff --git a/arch/s390/boot/uv.h b/arch/s390/boot/uv.h
index 690ce019af5a..0f3070856f8d 100644
--- a/arch/s390/boot/uv.h
+++ b/arch/s390/boot/uv.h
@@ -3,10 +3,13 @@
 #define BOOT_UV_H
 
 #if IS_ENABLED(CONFIG_KVM)
-void adjust_to_uv_max(unsigned long *vmax);
+unsigned long adjust_to_uv_max(unsigned long limit);
 void sanitize_prot_virt_host(void);
 #else
-static inline void adjust_to_uv_max(unsigned long *vmax) {}
+static inline unsigned long adjust_to_uv_max(unsigned long limit)
+{
+	return limit;
+}
 static inline void sanitize_prot_virt_host(void) {}
 #endif
 
diff --git a/arch/s390/crypto/aes_s390.c b/arch/s390/crypto/aes_s390.c
index 1023e9d43d44..526c3f40f6a2 100644
--- a/arch/s390/crypto/aes_s390.c
+++ b/arch/s390/crypto/aes_s390.c
@@ -1049,7 +1049,7 @@ out_err:
 	return ret;
 }
 
-module_cpu_feature_match(MSA, aes_s390_init);
+module_cpu_feature_match(S390_CPU_FEATURE_MSA, aes_s390_init);
 module_exit(aes_s390_fini);
 
 MODULE_ALIAS_CRYPTO("aes-all");
diff --git a/arch/s390/crypto/chacha-glue.c b/arch/s390/crypto/chacha-glue.c
index 2ec51f339cec..7752bd314558 100644
--- a/arch/s390/crypto/chacha-glue.c
+++ b/arch/s390/crypto/chacha-glue.c
@@ -121,7 +121,7 @@ static void __exit chacha_mod_fini(void)
 		crypto_unregister_skciphers(chacha_algs, ARRAY_SIZE(chacha_algs));
 }
 
-module_cpu_feature_match(VXRS, chacha_mod_init);
+module_cpu_feature_match(S390_CPU_FEATURE_VXRS, chacha_mod_init);
 module_exit(chacha_mod_fini);
 
 MODULE_DESCRIPTION("ChaCha20 stream cipher");
diff --git a/arch/s390/crypto/crc32-vx.c b/arch/s390/crypto/crc32-vx.c
index fafecad20752..017143e9cef7 100644
--- a/arch/s390/crypto/crc32-vx.c
+++ b/arch/s390/crypto/crc32-vx.c
@@ -298,7 +298,7 @@ static void __exit crc_vx_mod_exit(void)
 	crypto_unregister_shashes(crc32_vx_algs, ARRAY_SIZE(crc32_vx_algs));
 }
 
-module_cpu_feature_match(VXRS, crc_vx_mod_init);
+module_cpu_feature_match(S390_CPU_FEATURE_VXRS, crc_vx_mod_init);
 module_exit(crc_vx_mod_exit);
 
 MODULE_AUTHOR("Hendrik Brueckner <brueckner@linux.vnet.ibm.com>");
diff --git a/arch/s390/crypto/des_s390.c b/arch/s390/crypto/des_s390.c
index e013088b5115..8e75b83a5ddc 100644
--- a/arch/s390/crypto/des_s390.c
+++ b/arch/s390/crypto/des_s390.c
@@ -492,7 +492,7 @@ out_err:
 	return ret;
 }
 
-module_cpu_feature_match(MSA, des_s390_init);
+module_cpu_feature_match(S390_CPU_FEATURE_MSA, des_s390_init);
 module_exit(des_s390_exit);
 
 MODULE_ALIAS_CRYPTO("des");
diff --git a/arch/s390/crypto/ghash_s390.c b/arch/s390/crypto/ghash_s390.c
index 6b07a2f1ce8a..0800a2a5799f 100644
--- a/arch/s390/crypto/ghash_s390.c
+++ b/arch/s390/crypto/ghash_s390.c
@@ -145,7 +145,7 @@ static void __exit ghash_mod_exit(void)
 	crypto_unregister_shash(&ghash_alg);
 }
 
-module_cpu_feature_match(MSA, ghash_mod_init);
+module_cpu_feature_match(S390_CPU_FEATURE_MSA, ghash_mod_init);
 module_exit(ghash_mod_exit);
 
 MODULE_ALIAS_CRYPTO("ghash");
diff --git a/arch/s390/crypto/prng.c b/arch/s390/crypto/prng.c
index ae382bafc772..a077087bc6cc 100644
--- a/arch/s390/crypto/prng.c
+++ b/arch/s390/crypto/prng.c
@@ -907,5 +907,5 @@ static void __exit prng_exit(void)
 	}
 }
 
-module_cpu_feature_match(MSA, prng_init);
+module_cpu_feature_match(S390_CPU_FEATURE_MSA, prng_init);
 module_exit(prng_exit);
diff --git a/arch/s390/crypto/sha1_s390.c b/arch/s390/crypto/sha1_s390.c
index a3fabf310a38..bc3a22704e09 100644
--- a/arch/s390/crypto/sha1_s390.c
+++ b/arch/s390/crypto/sha1_s390.c
@@ -95,7 +95,7 @@ static void __exit sha1_s390_fini(void)
 	crypto_unregister_shash(&alg);
 }
 
-module_cpu_feature_match(MSA, sha1_s390_init);
+module_cpu_feature_match(S390_CPU_FEATURE_MSA, sha1_s390_init);
 module_exit(sha1_s390_fini);
 
 MODULE_ALIAS_CRYPTO("sha1");
diff --git a/arch/s390/crypto/sha256_s390.c b/arch/s390/crypto/sha256_s390.c
index 24983f175676..6f1ccdf93d3e 100644
--- a/arch/s390/crypto/sha256_s390.c
+++ b/arch/s390/crypto/sha256_s390.c
@@ -134,7 +134,7 @@ static void __exit sha256_s390_fini(void)
 	crypto_unregister_shash(&sha256_alg);
 }
 
-module_cpu_feature_match(MSA, sha256_s390_init);
+module_cpu_feature_match(S390_CPU_FEATURE_MSA, sha256_s390_init);
 module_exit(sha256_s390_fini);
 
 MODULE_ALIAS_CRYPTO("sha256");
diff --git a/arch/s390/crypto/sha3_256_s390.c b/arch/s390/crypto/sha3_256_s390.c
index 30ac49b635bf..e1350e033a32 100644
--- a/arch/s390/crypto/sha3_256_s390.c
+++ b/arch/s390/crypto/sha3_256_s390.c
@@ -137,7 +137,7 @@ static void __exit sha3_256_s390_fini(void)
 	crypto_unregister_shash(&sha3_256_alg);
 }
 
-module_cpu_feature_match(MSA, sha3_256_s390_init);
+module_cpu_feature_match(S390_CPU_FEATURE_MSA, sha3_256_s390_init);
 module_exit(sha3_256_s390_fini);
 
 MODULE_ALIAS_CRYPTO("sha3-256");
diff --git a/arch/s390/crypto/sha3_512_s390.c b/arch/s390/crypto/sha3_512_s390.c
index e70d50f7620f..06c142ed9bb1 100644
--- a/arch/s390/crypto/sha3_512_s390.c
+++ b/arch/s390/crypto/sha3_512_s390.c
@@ -147,7 +147,7 @@ static void __exit fini(void)
 	crypto_unregister_shash(&sha3_384_alg);
 }
 
-module_cpu_feature_match(MSA, init);
+module_cpu_feature_match(S390_CPU_FEATURE_MSA, init);
 module_exit(fini);
 
 MODULE_LICENSE("GPL");
diff --git a/arch/s390/crypto/sha512_s390.c b/arch/s390/crypto/sha512_s390.c
index 43ce4956df73..04f11c407763 100644
--- a/arch/s390/crypto/sha512_s390.c
+++ b/arch/s390/crypto/sha512_s390.c
@@ -142,7 +142,7 @@ static void __exit fini(void)
 	crypto_unregister_shash(&sha384_alg);
 }
 
-module_cpu_feature_match(MSA, init);
+module_cpu_feature_match(S390_CPU_FEATURE_MSA, init);
 module_exit(fini);
 
 MODULE_LICENSE("GPL");
diff --git a/arch/s390/include/asm/cpufeature.h b/arch/s390/include/asm/cpufeature.h
index 14cfd48d598e..931204613753 100644
--- a/arch/s390/include/asm/cpufeature.h
+++ b/arch/s390/include/asm/cpufeature.h
@@ -2,28 +2,21 @@
 /*
  * Module interface for CPU features
  *
- * Copyright IBM Corp. 2015
+ * Copyright IBM Corp. 2015, 2022
  * Author(s): Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
  */
 
 #ifndef __ASM_S390_CPUFEATURE_H
 #define __ASM_S390_CPUFEATURE_H
 
-#include <asm/elf.h>
+enum {
+	S390_CPU_FEATURE_MSA,
+	S390_CPU_FEATURE_VXRS,
+	S390_CPU_FEATURE_UV,
+	MAX_CPU_FEATURES
+};
 
-/* Hardware features on Linux on z Systems are indicated by facility bits that
- * are mapped to the so-called machine flags.  Particular machine flags are
- * then used to define ELF hardware capabilities; most notably hardware flags
- * that are essential for user space / glibc.
- *
- * Restrict the set of exposed CPU features to ELF hardware capabilities for
- * now.  Additional machine flags can be indicated by values larger than
- * MAX_ELF_HWCAP_FEATURES.
- */
-#define MAX_ELF_HWCAP_FEATURES	(8 * sizeof(elf_hwcap))
-#define MAX_CPU_FEATURES	MAX_ELF_HWCAP_FEATURES
-
-#define cpu_feature(feat)	ilog2(HWCAP_ ## feat)
+#define cpu_feature(feature)	(feature)
 
 int cpu_have_feature(unsigned int nr);
 
diff --git a/arch/s390/include/asm/mmu.h b/arch/s390/include/asm/mmu.h
index 1572b3634cdd..829d68e2c685 100644
--- a/arch/s390/include/asm/mmu.h
+++ b/arch/s390/include/asm/mmu.h
@@ -42,18 +42,4 @@ typedef struct {
 	.context.pgtable_list = LIST_HEAD_INIT(name.context.pgtable_list), \
 	.context.gmap_list = LIST_HEAD_INIT(name.context.gmap_list),
 
-static inline int tprot(unsigned long addr)
-{
-	int rc = -EFAULT;
-
-	asm volatile(
-		"	tprot	0(%1),0\n"
-		"0:	ipm	%0\n"
-		"	srl	%0,28\n"
-		"1:\n"
-		EX_TABLE(0b,1b)
-		: "+d" (rc) : "a" (addr) : "cc");
-	return rc;
-}
-
 #endif
diff --git a/arch/s390/include/asm/os_info.h b/arch/s390/include/asm/os_info.h
index 147a8d547ef9..85248d8fee0c 100644
--- a/arch/s390/include/asm/os_info.h
+++ b/arch/s390/include/asm/os_info.h
@@ -8,6 +8,8 @@
 #ifndef _ASM_S390_OS_INFO_H
 #define _ASM_S390_OS_INFO_H
 
+#include <linux/uio.h>
+
 #define OS_INFO_VERSION_MAJOR	1
 #define OS_INFO_VERSION_MINOR	1
 #define OS_INFO_MAGIC		0x4f53494e464f535aULL /* OSINFOSZ */
@@ -39,7 +41,20 @@ u32 os_info_csum(struct os_info *os_info);
 
 #ifdef CONFIG_CRASH_DUMP
 void *os_info_old_entry(int nr, unsigned long *size);
-int copy_oldmem_kernel(void *dst, unsigned long src, size_t count);
+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)
 {
diff --git a/arch/s390/include/asm/sclp.h b/arch/s390/include/asm/sclp.h
index addefe8ccdba..9d4c7f71e070 100644
--- a/arch/s390/include/asm/sclp.h
+++ b/arch/s390/include/asm/sclp.h
@@ -17,6 +17,7 @@
 #define EXT_SCCB_READ_CPU	(3 * PAGE_SIZE)
 
 #ifndef __ASSEMBLY__
+#include <linux/uio.h>
 #include <asm/chpid.h>
 #include <asm/cpu.h>
 
@@ -146,8 +147,7 @@ int sclp_pci_deconfigure(u32 fid);
 int sclp_ap_configure(u32 apid);
 int sclp_ap_deconfigure(u32 apid);
 int sclp_pci_report(struct zpci_report_error_header *report, u32 fh, u32 fid);
-int memcpy_hsa_kernel(void *dest, unsigned long src, size_t count);
-int memcpy_hsa_user(void __user *dest, unsigned long src, size_t count);
+size_t memcpy_hsa_iter(struct iov_iter *iter, unsigned long src, size_t count);
 void sclp_ocf_cpc_name_copy(char *dst);
 
 static inline int sclp_get_core_info(struct sclp_core_info *info, int early)
diff --git a/arch/s390/include/asm/uaccess.h b/arch/s390/include/asm/uaccess.h
index c2c9995466e0..f7038b800cc3 100644
--- a/arch/s390/include/asm/uaccess.h
+++ b/arch/s390/include/asm/uaccess.h
@@ -285,7 +285,6 @@ static inline unsigned long __must_check clear_user(void __user *to, unsigned lo
 	return __clear_user(to, n);
 }
 
-int copy_to_user_real(void __user *dest, unsigned long src, unsigned long count);
 void *s390_kernel_write(void *dst, const void *src, size_t size);
 
 int __noreturn __put_kernel_bad(void);
diff --git a/arch/s390/include/asm/unwind.h b/arch/s390/include/asm/unwind.h
index 0bf06f1682d8..02462e7100c1 100644
--- a/arch/s390/include/asm/unwind.h
+++ b/arch/s390/include/asm/unwind.h
@@ -47,7 +47,7 @@ struct unwind_state {
 static inline unsigned long unwind_recover_ret_addr(struct unwind_state *state,
 						    unsigned long ip)
 {
-	ip = ftrace_graph_ret_addr(state->task, &state->graph_idx, ip, NULL);
+	ip = ftrace_graph_ret_addr(state->task, &state->graph_idx, ip, (void *)state->sp);
 	if (is_kretprobe_trampoline(ip))
 		ip = kretprobe_find_ret_addr(state->task, (void *)state->sp, &state->kr_cur);
 	return ip;
diff --git a/arch/s390/kernel/Makefile b/arch/s390/kernel/Makefile
index 27d6b3c7aa06..3cbfa9fddd9a 100644
--- a/arch/s390/kernel/Makefile
+++ b/arch/s390/kernel/Makefile
@@ -35,7 +35,7 @@ CFLAGS_unwind_bc.o	+= -fno-optimize-sibling-calls
 
 obj-y	:= traps.o time.o process.o earlypgm.o early.o setup.o idle.o vtime.o
 obj-y	+= processor.o syscall.o ptrace.o signal.o cpcmd.o ebcdic.o nmi.o
-obj-y	+= debug.o irq.o ipl.o dis.o diag.o vdso.o
+obj-y	+= debug.o irq.o ipl.o dis.o diag.o vdso.o cpufeature.o
 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
diff --git a/arch/s390/kernel/cpufeature.c b/arch/s390/kernel/cpufeature.c
new file mode 100644
index 000000000000..1b2ae42a0c15
--- /dev/null
+++ b/arch/s390/kernel/cpufeature.c
@@ -0,0 +1,46 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright IBM Corp. 2022
+ */
+
+#include <linux/cpufeature.h>
+#include <linux/bug.h>
+#include <asm/elf.h>
+
+enum {
+	TYPE_HWCAP,
+	TYPE_FACILITY,
+};
+
+struct s390_cpu_feature {
+	unsigned int type	: 4;
+	unsigned int num	: 28;
+};
+
+static struct s390_cpu_feature s390_cpu_features[MAX_CPU_FEATURES] = {
+	[S390_CPU_FEATURE_MSA]	= {.type = TYPE_HWCAP, .num = HWCAP_NR_MSA},
+	[S390_CPU_FEATURE_VXRS]	= {.type = TYPE_HWCAP, .num = HWCAP_NR_VXRS},
+	[S390_CPU_FEATURE_UV]	= {.type = TYPE_FACILITY, .num = 158},
+};
+
+/*
+ * cpu_have_feature - Test CPU features on module initialization
+ */
+int cpu_have_feature(unsigned int num)
+{
+	struct s390_cpu_feature *feature;
+
+	if (WARN_ON_ONCE(num >= MAX_CPU_FEATURES))
+		return 0;
+	feature = &s390_cpu_features[num];
+	switch (feature->type) {
+	case TYPE_HWCAP:
+		return !!(elf_hwcap & BIT(feature->num));
+	case TYPE_FACILITY:
+		return test_facility(feature->num);
+	default:
+		WARN_ON_ONCE(1);
+		return 0;
+	}
+}
+EXPORT_SYMBOL(cpu_have_feature);
diff --git a/arch/s390/kernel/crash_dump.c b/arch/s390/kernel/crash_dump.c
index 28124d0fa1d5..bad8f47fc5d6 100644
--- a/arch/s390/kernel/crash_dump.c
+++ b/arch/s390/kernel/crash_dump.c
@@ -53,6 +53,8 @@ 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
@@ -63,7 +65,7 @@ struct save_area * __init save_area_alloc(bool is_boot_cpu)
 
 	sa = memblock_alloc(sizeof(*sa), 8);
 	if (!sa)
-		panic("Failed to allocate save area\n");
+		return NULL;
 
 	if (is_boot_cpu)
 		list_add(&sa->list, &dump_save_areas);
@@ -114,80 +116,35 @@ void __init save_area_add_vxrs(struct save_area *sa, __vector128 *vxrs)
 	memcpy(sa->vxrs_high, vxrs + 16, 16 * sizeof(__vector128));
 }
 
-/*
- * Return physical address for virtual address
- */
-static inline void *load_real_addr(void *addr)
-{
-	unsigned long real_addr;
-
-	asm volatile(
-		   "	lra     %0,0(%1)\n"
-		   "	jz	0f\n"
-		   "	la	%0,0\n"
-		   "0:"
-		   : "=a" (real_addr) : "a" (addr) : "cc");
-	return (void *)real_addr;
-}
-
-/*
- * Copy memory of the old, dumped system to a kernel space virtual address
- */
-int copy_oldmem_kernel(void *dst, unsigned long src, size_t count)
+static size_t copy_to_iter_real(struct iov_iter *iter, unsigned long src, size_t count)
 {
-	unsigned long len;
-	void *ra;
-	int rc;
+	size_t len, copied, res = 0;
 
+	mutex_lock(&memcpy_real_mutex);
 	while (count) {
-		if (!oldmem_data.start && src < sclp.hsa_size) {
-			/* Copy from zfcp/nvme dump HSA area */
-			len = min(count, sclp.hsa_size - src);
-			rc = memcpy_hsa_kernel(dst, src, len);
-			if (rc)
-				return rc;
-		} else {
-			/* Check for swapped kdump oldmem areas */
-			if (oldmem_data.start && src - oldmem_data.start < oldmem_data.size) {
-				src -= oldmem_data.start;
-				len = min(count, oldmem_data.size - src);
-			} else if (oldmem_data.start && src < oldmem_data.size) {
-				len = min(count, oldmem_data.size - src);
-				src += oldmem_data.start;
-			} else {
-				len = count;
-			}
-			if (is_vmalloc_or_module_addr(dst)) {
-				ra = load_real_addr(dst);
-				len = min(PAGE_SIZE - offset_in_page(ra), len);
-			} else {
-				ra = dst;
-			}
-			if (memcpy_real(ra, src, len))
-				return -EFAULT;
-		}
-		dst += len;
-		src += len;
-		count -= len;
+		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;
 	}
-	return 0;
+	mutex_unlock(&memcpy_real_mutex);
+	return res;
 }
 
-/*
- * Copy memory of the old, dumped system to a user space virtual address
- */
-static int copy_oldmem_user(void __user *dst, unsigned long src, size_t count)
+size_t copy_oldmem_iter(struct iov_iter *iter, unsigned long src, size_t count)
 {
-	unsigned long len;
-	int rc;
+	size_t len, copied, res = 0;
 
 	while (count) {
 		if (!oldmem_data.start && src < sclp.hsa_size) {
 			/* Copy from zfcp/nvme dump HSA area */
 			len = min(count, sclp.hsa_size - src);
-			rc = memcpy_hsa_user(dst, src, len);
-			if (rc)
-				return rc;
+			copied = memcpy_hsa_iter(iter, src, len);
 		} else {
 			/* Check for swapped kdump oldmem areas */
 			if (oldmem_data.start && src - oldmem_data.start < oldmem_data.size) {
@@ -199,15 +156,15 @@ static int copy_oldmem_user(void __user *dst, unsigned long src, size_t count)
 			} else {
 				len = count;
 			}
-			rc = copy_to_user_real(dst, src, count);
-			if (rc)
-				return rc;
+			copied = copy_to_iter_real(iter, src, len);
 		}
-		dst += len;
-		src += len;
-		count -= len;
+		count -= copied;
+		src += copied;
+		res += copied;
+		if (copied < len)
+			break;
 	}
-	return 0;
+	return res;
 }
 
 /*
@@ -217,26 +174,9 @@ ssize_t copy_oldmem_page(struct iov_iter *iter, unsigned long pfn, size_t csize,
 			 unsigned long offset)
 {
 	unsigned long src;
-	int rc;
 
-	if (!(iter_is_iovec(iter) || iov_iter_is_kvec(iter)))
-		return -EINVAL;
-	/* Multi-segment iterators are not supported */
-	if (iter->nr_segs > 1)
-		return -EINVAL;
-	if (!csize)
-		return 0;
 	src = pfn_to_phys(pfn) + offset;
-
-	/* XXX: pass the iov_iter down to a common function */
-	if (iter_is_iovec(iter))
-		rc = copy_oldmem_user(iter->iov->iov_base, src, csize);
-	else
-		rc = copy_oldmem_kernel(iter->kvec->iov_base, src, csize);
-	if (rc < 0)
-		return rc;
-	iov_iter_advance(iter, csize);
-	return csize;
+	return copy_oldmem_iter(iter, src, csize);
 }
 
 /*
diff --git a/arch/s390/kernel/nmi.c b/arch/s390/kernel/nmi.c
index 53ed3884fe64..60ac66aab163 100644
--- a/arch/s390/kernel/nmi.c
+++ b/arch/s390/kernel/nmi.c
@@ -11,6 +11,7 @@
 #include <linux/kernel_stat.h>
 #include <linux/init.h>
 #include <linux/errno.h>
+#include <linux/entry-common.h>
 #include <linux/hardirq.h>
 #include <linux/log2.h>
 #include <linux/kprobes.h>
@@ -397,11 +398,12 @@ int notrace s390_do_machine_check(struct pt_regs *regs)
 	static unsigned long long last_ipd;
 	struct mcck_struct *mcck;
 	unsigned long long tmp;
+	irqentry_state_t irq_state;
 	union mci mci;
 	unsigned long mcck_dam_code;
 	int mcck_pending = 0;
 
-	nmi_enter();
+	irq_state = irqentry_nmi_enter(regs);
 
 	if (user_mode(regs))
 		update_timer_mcck();
@@ -504,14 +506,14 @@ int notrace s390_do_machine_check(struct pt_regs *regs)
 	clear_cpu_flag(CIF_MCCK_GUEST);
 
 	if (user_mode(regs) && mcck_pending) {
-		nmi_exit();
+		irqentry_nmi_exit(regs, irq_state);
 		return 1;
 	}
 
 	if (mcck_pending)
 		schedule_mcck_handler();
 
-	nmi_exit();
+	irqentry_nmi_exit(regs, irq_state);
 	return 0;
 }
 NOKPROBE_SYMBOL(s390_do_machine_check);
diff --git a/arch/s390/kernel/processor.c b/arch/s390/kernel/processor.c
index aa0e0e7fc773..a194611ba88c 100644
--- a/arch/s390/kernel/processor.c
+++ b/arch/s390/kernel/processor.c
@@ -8,7 +8,6 @@
 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
 
 #include <linux/stop_machine.h>
-#include <linux/cpufeature.h>
 #include <linux/bitops.h>
 #include <linux/kernel.h>
 #include <linux/random.h>
@@ -96,15 +95,6 @@ void cpu_init(void)
 	enter_lazy_tlb(&init_mm, current);
 }
 
-/*
- * cpu_have_feature - Test CPU features on module initialization
- */
-int cpu_have_feature(unsigned int num)
-{
-	return elf_hwcap & (1UL << num);
-}
-EXPORT_SYMBOL(cpu_have_feature);
-
 static void show_facilities(struct seq_file *m)
 {
 	unsigned int bit;
diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c
index ebad41afe355..ed4fbbbdd1b0 100644
--- a/arch/s390/kernel/setup.c
+++ b/arch/s390/kernel/setup.c
@@ -474,19 +474,18 @@ static void __init setup_lowcore_dat_off(void)
 	lc->restart_data = 0;
 	lc->restart_source = -1U;
 
-	mcck_stack = (unsigned long)memblock_alloc(THREAD_SIZE, THREAD_SIZE);
-	if (!mcck_stack)
-		panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
-		      __func__, THREAD_SIZE, THREAD_SIZE);
-	lc->mcck_stack = mcck_stack + STACK_INIT_OFFSET;
-
-	/* Setup absolute zero lowcore */
 	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);
 
+	mcck_stack = (unsigned long)memblock_alloc(THREAD_SIZE, THREAD_SIZE);
+	if (!mcck_stack)
+		panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
+		      __func__, THREAD_SIZE, THREAD_SIZE);
+	lc->mcck_stack = mcck_stack + STACK_INIT_OFFSET;
+
 	lc->spinlock_lockval = arch_spin_lockval(0);
 	lc->spinlock_index = 0;
 	arch_spin_lock_setup(0);
diff --git a/arch/s390/mm/maccess.c b/arch/s390/mm/maccess.c
index 421efa46946b..d6d84e02f35a 100644
--- a/arch/s390/mm/maccess.c
+++ b/arch/s390/mm/maccess.c
@@ -172,32 +172,6 @@ void memcpy_absolute(void *dest, void *src, size_t count)
 }
 
 /*
- * Copy memory from kernel (real) to user (virtual)
- */
-int copy_to_user_real(void __user *dest, unsigned long src, unsigned long count)
-{
-	int offs = 0, size, rc;
-	char *buf;
-
-	buf = (char *) __get_free_page(GFP_KERNEL);
-	if (!buf)
-		return -ENOMEM;
-	rc = -EFAULT;
-	while (offs < count) {
-		size = min(PAGE_SIZE, count - offs);
-		if (memcpy_real(buf, src + offs, size))
-			goto out;
-		if (copy_to_user(dest + offs, buf, size))
-			goto out;
-		offs += size;
-	}
-	rc = 0;
-out:
-	free_page((unsigned long) buf);
-	return rc;
-}
-
-/*
  * Check if physical address is within prefix or zero page
  */
 static int is_swapped(phys_addr_t addr)