6 files changed, 86 insertions, 109 deletions

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);