Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux.git

11 files changed, 237 insertions, 134 deletions

diff --git a/arch/s390/kernel/Makefile b/arch/s390/kernel/Makefile
index 27d6b3c7aa06..45e4b2f41e05 100644
--- a/arch/s390/kernel/Makefile
+++ b/arch/s390/kernel/Makefile
@@ -35,12 +35,12 @@ 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
 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
 
diff --git a/arch/s390/kernel/abs_lowcore.c b/arch/s390/kernel/abs_lowcore.c
new file mode 100644
index 000000000000..dc9f0ecd4695
--- /dev/null
+++ b/arch/s390/kernel/abs_lowcore.c
@@ -0,0 +1,88 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/pgtable.h>
+#include <asm/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)
+{
+	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);
+		if (rc) {
+			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();
+}
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/ipl.c b/arch/s390/kernel/ipl.c
index 1cc85b8ff42e..325cbf69ebbd 100644
--- a/arch/s390/kernel/ipl.c
+++ b/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);
 }
 
diff --git a/arch/s390/kernel/machine_kexec.c b/arch/s390/kernel/machine_kexec.c
index ab761c008f98..4579b42286d5 100644
--- a/arch/s390/kernel/machine_kexec.c
+++ b/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)
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/os_info.c b/arch/s390/kernel/os_info.c
index 1acc2e05d70f..506ccb74d2d0 100644
--- a/arch/s390/kernel/os_info.c
+++ b/arch/s390/kernel/os_info.c
@@ -13,7 +13,7 @@
 #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/asm-offsets.h>
 
@@ -57,13 +57,16 @@ 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
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..61cba049bb9b 100644
--- a/arch/s390/kernel/setup.c
+++ b/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>
@@ -411,8 +411,9 @@ 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;
@@ -474,19 +475,20 @@ static void __init setup_lowcore_dat_off(void)
 	lc->restart_data = 0;
 	lc->restart_source = -1U;
 
+	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;
+	put_abs_lowcore(abs_lc, flags);
+
 	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);
-
 	lc->spinlock_lockval = arch_spin_lockval(0);
 	lc->spinlock_index = 0;
 	arch_spin_lock_setup(0);
@@ -500,20 +502,25 @@ 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;
 	S390_lowcore.svc_new_psw.mask |= PSW_MASK_DAT;
 	S390_lowcore.program_new_psw.mask |= PSW_MASK_DAT;
 	S390_lowcore.io_new_psw.mask |= PSW_MASK_DAT;
-	__ctl_store(S390_lowcore.cregs_save_area, 0, 15);
 	__ctl_set_bit(0, 28);
-	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]);
+	__ctl_store(S390_lowcore.cregs_save_area, 0, 15);
+	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);
+	if (abs_lowcore_map(0, lowcore_ptr[0]))
+		panic("Couldn't setup absolute lowcore");
+	abs_lowcore_mapped = true;
 }
 
 static struct resource code_resource = {
diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c
index 30c91d565933..40876d809ea6 100644
--- a/arch/s390/kernel/smp.c
+++ b/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>
@@ -212,10 +212,14 @@ 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))
+		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 +241,7 @@ 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 +320,12 @@ 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 +340,12 @@ 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 +591,8 @@ 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 +603,11 @@ 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);
 }
@@ -1281,6 +1295,8 @@ 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))
+		panic("Couldn't remap absolute lowcore");
 	lowcore_ptr[0] = lc;
 	local_mcck_enable();
 	local_irq_restore(flags);