diff --git a/arch/s390/boot/boot.h b/arch/s390/boot/boot.h
index 0cfa84a42ec1..69f261566a64 100644
--- a/arch/s390/boot/boot.h
+++ b/arch/s390/boot/boot.h
@@ -57,6 +57,7 @@ unsigned long physmem_alloc_range(enum reserved_range_type type, unsigned long s
 				  unsigned long align, unsigned long min, unsigned long max,
 				  bool die_on_oom);
 unsigned long get_physmem_alloc_pos(void);
+void dump_physmem_reserved(void);
 bool ipl_report_certs_intersects(unsigned long addr, unsigned long size,
 				 unsigned long *intersection_start);
 bool is_ipl_block_dump(void);
diff --git a/arch/s390/boot/physmem_info.c b/arch/s390/boot/physmem_info.c
index 37d201986261..aa096ef68e8c 100644
--- a/arch/s390/boot/physmem_info.c
+++ b/arch/s390/boot/physmem_info.c
@@ -1,4 +1,5 @@
 // SPDX-License-Identifier: GPL-2.0
+#define boot_fmt(fmt) "physmem: " fmt
 #include <linux/processor.h>
 #include <linux/errno.h>
 #include <linux/init.h>
@@ -28,7 +29,7 @@ static struct physmem_range *__get_physmem_range_ptr(u32 n)
 		return &physmem_info.online[n];
 	if (unlikely(!physmem_info.online_extended)) {
 		physmem_info.online_extended = (struct physmem_range *)physmem_alloc_range(
-			RR_MEM_DETECT_EXTENDED, ENTRIES_EXTENDED_MAX, sizeof(long), 0,
+			RR_MEM_DETECT_EXT, ENTRIES_EXTENDED_MAX, sizeof(long), 0,
 			physmem_alloc_pos, true);
 	}
 	return &physmem_info.online_extended[n - MEM_INLINED_ENTRIES];
@@ -207,11 +208,16 @@ unsigned long detect_max_physmem_end(void)
 		max_physmem_end = search_mem_end();
 		physmem_info.info_source = MEM_DETECT_BIN_SEARCH;
 	}
+	boot_debug("Max physical memory: 0x%016lx (info source: %s)\n", max_physmem_end,
+		   get_physmem_info_source());
 	return max_physmem_end;
 }
 
 void detect_physmem_online_ranges(unsigned long max_physmem_end)
 {
+	unsigned long start, end;
+	int i;
+
 	if (!sclp_early_read_storage_info()) {
 		physmem_info.info_source = MEM_DETECT_SCLP_STOR_INFO;
 	} else if (physmem_info.info_source == MEM_DETECT_DIAG500_STOR_LIMIT) {
@@ -226,12 +232,16 @@ void detect_physmem_online_ranges(unsigned long max_physmem_end)
 	} else if (max_physmem_end) {
 		add_physmem_online_range(0, max_physmem_end);
 	}
+	boot_debug("Online memory ranges (info source: %s):\n", get_physmem_info_source());
+	for_each_physmem_online_range(i, &start, &end)
+		boot_debug(" online [%d]:   0x%016lx-0x%016lx\n", i, start, end);
 }
 
 void physmem_set_usable_limit(unsigned long limit)
 {
 	physmem_info.usable = limit;
 	physmem_alloc_pos = limit;
+	boot_debug("Usable memory limit: 0x%016lx\n", limit);
 }
 
 static void die_oom(unsigned long size, unsigned long align, unsigned long min, unsigned long max)
@@ -265,14 +275,23 @@ static void die_oom(unsigned long size, unsigned long align, unsigned long min,
 	disabled_wait();
 }
 
-void physmem_reserve(enum reserved_range_type type, unsigned long addr, unsigned long size)
+static void _physmem_reserve(enum reserved_range_type type, unsigned long addr, unsigned long size)
 {
 	physmem_info.reserved[type].start = addr;
 	physmem_info.reserved[type].end = addr + size;
 }
 
+void physmem_reserve(enum reserved_range_type type, unsigned long addr, unsigned long size)
+{
+	_physmem_reserve(type, addr, size);
+	boot_debug("%-14s 0x%016lx-0x%016lx %s\n", "Reserve:", addr, addr + size,
+		   get_rr_type_name(type));
+}
+
 void physmem_free(enum reserved_range_type type)
 {
+	boot_debug("%-14s 0x%016lx-0x%016lx %s\n", "Free:", physmem_info.reserved[type].start,
+		   physmem_info.reserved[type].end, get_rr_type_name(type));
 	physmem_info.reserved[type].start = 0;
 	physmem_info.reserved[type].end = 0;
 }
@@ -339,7 +358,9 @@ unsigned long physmem_alloc_range(enum reserved_range_type type, unsigned long s
 	max = min(max, physmem_alloc_pos);
 	addr = __physmem_alloc_range(size, align, min, max, 0, NULL, die_on_oom);
 	if (addr)
-		physmem_reserve(type, addr, size);
+		_physmem_reserve(type, addr, size);
+	boot_debug("%-14s 0x%016lx-0x%016lx %s\n", "Alloc range:", addr, addr + size,
+		   get_rr_type_name(type));
 	return addr;
 }
 
@@ -347,7 +368,7 @@ unsigned long physmem_alloc(enum reserved_range_type type, unsigned long size,
 			    unsigned long align, bool die_on_oom)
 {
 	struct reserved_range *range = &physmem_info.reserved[type];
-	struct reserved_range *new_range;
+	struct reserved_range *new_range = NULL;
 	unsigned int ranges_left;
 	unsigned long addr;
 
@@ -371,6 +392,10 @@ unsigned long physmem_alloc(enum reserved_range_type type, unsigned long size,
 		}
 		range->end = addr + size;
 	}
+	if (type != RR_VMEM) {
+		boot_debug("%-14s 0x%016lx-0x%016lx %-20s align 0x%lx split %d\n", "Alloc topdown:",
+			   addr, addr + size, get_rr_type_name(type), align, !!new_range);
+	}
 	range->start = addr;
 	physmem_alloc_pos = addr;
 	physmem_alloc_ranges = ranges_left;
@@ -387,3 +412,19 @@ unsigned long get_physmem_alloc_pos(void)
 {
 	return physmem_alloc_pos;
 }
+
+void dump_physmem_reserved(void)
+{
+	struct reserved_range *range;
+	enum reserved_range_type t;
+	unsigned long start, end;
+
+	boot_debug("Reserved memory ranges:\n");
+	for_each_physmem_reserved_range(t, range, &start, &end) {
+		if (end) {
+			boot_debug("%-14s 0x%016lx-0x%016lx @%012lx chain %012lx\n",
+				   get_rr_type_name(t), start, end, (unsigned long)range,
+				   (unsigned long)range->chain);
+		}
+	}
+}
diff --git a/arch/s390/boot/startup.c b/arch/s390/boot/startup.c
index e9ae589c6169..86693d838e97 100644
--- a/arch/s390/boot/startup.c
+++ b/arch/s390/boot/startup.c
@@ -525,6 +525,7 @@ void startup_kernel(void)
 			    __kaslr_offset, __kaslr_offset_phys);
 	kaslr_adjust_got(__kaslr_offset);
 	setup_vmem(__kaslr_offset, __kaslr_offset + kernel_size, asce_limit);
+	dump_physmem_reserved();
 	copy_bootdata();
 	__apply_alternatives((struct alt_instr *)_vmlinux_info.alt_instructions,
 			     (struct alt_instr *)_vmlinux_info.alt_instructions_end,
diff --git a/arch/s390/include/asm/physmem_info.h b/arch/s390/include/asm/physmem_info.h
index 51b68a43e195..7ef3bbec98b0 100644
--- a/arch/s390/include/asm/physmem_info.h
+++ b/arch/s390/include/asm/physmem_info.h
@@ -26,7 +26,7 @@ enum reserved_range_type {
 	RR_AMODE31,
 	RR_IPLREPORT,
 	RR_CERT_COMP_LIST,
-	RR_MEM_DETECT_EXTENDED,
+	RR_MEM_DETECT_EXT,
 	RR_VMEM,
 	RR_MAX
 };
@@ -128,7 +128,7 @@ static inline const char *get_rr_type_name(enum reserved_range_type t)
 	RR_TYPE_NAME(AMODE31);
 	RR_TYPE_NAME(IPLREPORT);
 	RR_TYPE_NAME(CERT_COMP_LIST);
-	RR_TYPE_NAME(MEM_DETECT_EXTENDED);
+	RR_TYPE_NAME(MEM_DETECT_EXT);
 	RR_TYPE_NAME(VMEM);
 	default:
 		return "UNKNOWN";
diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c
index 20fc68bdefa1..0fcb2a4e3f5e 100644
--- a/arch/s390/kernel/setup.c
+++ b/arch/s390/kernel/setup.c
@@ -702,7 +702,7 @@ static void __init reserve_physmem_info(void)
 {
 	unsigned long addr, size;
 
-	if (get_physmem_reserved(RR_MEM_DETECT_EXTENDED, &addr, &size))
+	if (get_physmem_reserved(RR_MEM_DETECT_EXT, &addr, &size))
 		memblock_reserve(addr, size);
 }
 
@@ -710,7 +710,7 @@ static void __init free_physmem_info(void)
 {
 	unsigned long addr, size;
 
-	if (get_physmem_reserved(RR_MEM_DETECT_EXTENDED, &addr, &size))
+	if (get_physmem_reserved(RR_MEM_DETECT_EXT, &addr, &size))
 		memblock_phys_free(addr, size);
 }