23 files changed, 911 insertions, 1004 deletions

diff --git a/arch/s390/boot/Makefile b/arch/s390/boot/Makefile
index cebd4ca16916..c7c81e5f9218 100644
--- a/arch/s390/boot/Makefile
+++ b/arch/s390/boot/Makefile
@@ -35,7 +35,7 @@ endif
 
 CFLAGS_sclp_early_core.o += -I$(srctree)/drivers/s390/char
 
-obj-y	:= head.o als.o startup.o mem_detect.o ipl_parm.o ipl_report.o vmem.o
+obj-y	:= head.o als.o startup.o physmem_info.o ipl_parm.o ipl_report.o vmem.o
 obj-y	+= string.o ebcdic.o sclp_early_core.o mem.o ipl_vmparm.o cmdline.o
 obj-y	+= version.o pgm_check_info.o ctype.o ipl_data.o machine_kexec_reloc.o
 obj-$(findstring y, $(CONFIG_PROTECTED_VIRTUALIZATION_GUEST) $(CONFIG_PGSTE))	+= uv.o
diff --git a/arch/s390/boot/boot.h b/arch/s390/boot/boot.h
index 58ce701d6110..872963c8a0ab 100644
--- a/arch/s390/boot/boot.h
+++ b/arch/s390/boot/boot.h
@@ -8,6 +8,8 @@
 
 #ifndef __ASSEMBLY__
 
+#include <asm/physmem_info.h>
+
 struct machine_info {
 	unsigned char has_edat1 : 1;
 	unsigned char has_edat2 : 1;
@@ -30,24 +32,44 @@ struct vmlinux_info {
 	unsigned long init_mm_off;
 	unsigned long swapper_pg_dir_off;
 	unsigned long invalid_pg_dir_off;
+#ifdef CONFIG_KASAN
+	unsigned long kasan_early_shadow_page_off;
+	unsigned long kasan_early_shadow_pte_off;
+	unsigned long kasan_early_shadow_pmd_off;
+	unsigned long kasan_early_shadow_pud_off;
+	unsigned long kasan_early_shadow_p4d_off;
+#endif
 };
 
 void startup_kernel(void);
-unsigned long detect_memory(unsigned long *safe_addr);
-void mem_detect_set_usable_limit(unsigned long limit);
+unsigned long detect_max_physmem_end(void);
+void detect_physmem_online_ranges(unsigned long max_physmem_end);
+void physmem_set_usable_limit(unsigned long limit);
+void physmem_reserve(enum reserved_range_type type, unsigned long addr, unsigned long size);
+void physmem_free(enum reserved_range_type type);
+/* for continuous/multiple allocations per type */
+unsigned long physmem_alloc_top_down(enum reserved_range_type type, unsigned long size,
+				     unsigned long align);
+/* for single allocations, 1 per type */
+unsigned long physmem_alloc_range(enum reserved_range_type type, unsigned long size,
+				  unsigned long align, unsigned long min, unsigned long max,
+				  bool die_on_oom);
+bool ipl_report_certs_intersects(unsigned long addr, unsigned long size,
+				 unsigned long *intersection_start);
 bool is_ipl_block_dump(void);
 void store_ipl_parmblock(void);
-unsigned long read_ipl_report(unsigned long safe_addr);
+int read_ipl_report(void);
+void save_ipl_cert_comp_list(void);
 void setup_boot_command_line(void);
 void parse_boot_command_line(void);
 void verify_facilities(void);
 void print_missing_facilities(void);
 void sclp_early_setup_buffer(void);
 void print_pgm_check_info(void);
-unsigned long get_random_base(unsigned long safe_addr);
+unsigned long get_random_base(void);
 void setup_vmem(unsigned long asce_limit);
-unsigned long vmem_estimate_memory_needs(unsigned long online_mem_total);
 void __printf(1, 2) decompressor_printk(const char *fmt, ...);
+void print_stacktrace(unsigned long sp);
 void error(char *m);
 
 extern struct machine_info machine;
@@ -62,7 +84,7 @@ extern char __boot_data_start[], __boot_data_end[];
 extern char __boot_data_preserved_start[], __boot_data_preserved_end[];
 extern char _decompressor_syms_start[], _decompressor_syms_end[];
 extern char _stack_start[], _stack_end[];
-extern char _end[];
+extern char _end[], _decompressor_end[];
 extern unsigned char _compressed_start[];
 extern unsigned char _compressed_end[];
 extern struct vmlinux_info _vmlinux_info;
@@ -70,5 +92,10 @@ extern struct vmlinux_info _vmlinux_info;
 
 #define __abs_lowcore_pa(x)	(((unsigned long)(x) - __abs_lowcore) % sizeof(struct lowcore))
 
+static inline bool intersects(unsigned long addr0, unsigned long size0,
+			      unsigned long addr1, unsigned long size1)
+{
+	return addr0 + size0 > addr1 && addr1 + size1 > addr0;
+}
 #endif /* __ASSEMBLY__ */
 #endif /* BOOT_BOOT_H */
diff --git a/arch/s390/boot/ipl_report.c b/arch/s390/boot/ipl_report.c
index 9b14045065b6..1803035e68d2 100644
--- a/arch/s390/boot/ipl_report.c
+++ b/arch/s390/boot/ipl_report.c
@@ -5,6 +5,7 @@
 #include <asm/sclp.h>
 #include <asm/sections.h>
 #include <asm/boot_data.h>
+#include <asm/physmem_info.h>
 #include <uapi/asm/ipl.h>
 #include "boot.h"
 
@@ -16,20 +17,16 @@ unsigned long __bootdata_preserved(ipl_cert_list_size);
 unsigned long __bootdata(early_ipl_comp_list_addr);
 unsigned long __bootdata(early_ipl_comp_list_size);
 
+static struct ipl_rb_certificates *certs;
+static struct ipl_rb_components *comps;
+static bool ipl_report_needs_saving;
+
 #define for_each_rb_entry(entry, rb) \
 	for (entry = rb->entries; \
 	     (void *) entry + sizeof(*entry) <= (void *) rb + rb->len; \
 	     entry++)
 
-static inline bool intersects(unsigned long addr0, unsigned long size0,
-			      unsigned long addr1, unsigned long size1)
-{
-	return addr0 + size0 > addr1 && addr1 + size1 > addr0;
-}
-
-static unsigned long find_bootdata_space(struct ipl_rb_components *comps,
-					 struct ipl_rb_certificates *certs,
-					 unsigned long safe_addr)
+static unsigned long get_cert_comp_list_size(void)
 {
 	struct ipl_rb_certificate_entry *cert;
 	struct ipl_rb_component_entry *comp;
@@ -44,36 +41,27 @@ static unsigned long find_bootdata_space(struct ipl_rb_components *comps,
 	ipl_cert_list_size = 0;
 	for_each_rb_entry(cert, certs)
 		ipl_cert_list_size += sizeof(unsigned int) + cert->len;
-	size = ipl_cert_list_size + early_ipl_comp_list_size;
+	return ipl_cert_list_size + early_ipl_comp_list_size;
+}
 
-	/*
-	 * Start from safe_addr to find a free memory area large
-	 * enough for the IPL report boot data. This area is used
-	 * for ipl_cert_list_addr/ipl_cert_list_size and
-	 * early_ipl_comp_list_addr/early_ipl_comp_list_size. It must
-	 * not overlap with any component or any certificate.
-	 */
-repeat:
-	if (IS_ENABLED(CONFIG_BLK_DEV_INITRD) && initrd_data.start && initrd_data.size &&
-	    intersects(initrd_data.start, initrd_data.size, safe_addr, size))
-		safe_addr = initrd_data.start + initrd_data.size;
-	for_each_rb_entry(comp, comps)
-		if (intersects(safe_addr, size, comp->addr, comp->len)) {
-			safe_addr = comp->addr + comp->len;
-			goto repeat;
-		}
-	for_each_rb_entry(cert, certs)
-		if (intersects(safe_addr, size, cert->addr, cert->len)) {
-			safe_addr = cert->addr + cert->len;
-			goto repeat;
-		}
-	early_ipl_comp_list_addr = safe_addr;
-	ipl_cert_list_addr = safe_addr + early_ipl_comp_list_size;
+bool ipl_report_certs_intersects(unsigned long addr, unsigned long size,
+				 unsigned long *intersection_start)
+{
+	struct ipl_rb_certificate_entry *cert;
 
-	return safe_addr + size;
+	if (!ipl_report_needs_saving)
+		return false;
+
+	for_each_rb_entry(cert, certs) {
+		if (intersects(addr, size, cert->addr, cert->len)) {
+			*intersection_start = cert->addr;
+			return true;
+		}
+	}
+	return false;
 }
 
-static void copy_components_bootdata(struct ipl_rb_components *comps)
+static void copy_components_bootdata(void)
 {
 	struct ipl_rb_component_entry *comp, *ptr;
 
@@ -82,7 +70,7 @@ static void copy_components_bootdata(struct ipl_rb_components *comps)
 		memcpy(ptr++, comp, sizeof(*ptr));
 }
 
-static void copy_certificates_bootdata(struct ipl_rb_certificates *certs)
+static void copy_certificates_bootdata(void)
 {
 	struct ipl_rb_certificate_entry *cert;
 	void *ptr;
@@ -96,10 +84,8 @@ static void copy_certificates_bootdata(struct ipl_rb_certificates *certs)
 	}
 }
 
-unsigned long read_ipl_report(unsigned long safe_addr)
+int read_ipl_report(void)
 {
-	struct ipl_rb_certificates *certs;
-	struct ipl_rb_components *comps;
 	struct ipl_pl_hdr *pl_hdr;
 	struct ipl_rl_hdr *rl_hdr;
 	struct ipl_rb_hdr *rb_hdr;
@@ -112,7 +98,7 @@ unsigned long read_ipl_report(unsigned long safe_addr)
 	 */
 	if (!ipl_block_valid ||
 	    !(ipl_block.hdr.flags & IPL_PL_FLAG_IPLSR))
-		return safe_addr;
+		return -1;
 	ipl_secure_flag = !!(ipl_block.hdr.flags & IPL_PL_FLAG_SIPL);
 	/*
 	 * There is an IPL report, to find it load the pointer to the
@@ -150,16 +136,30 @@ unsigned long read_ipl_report(unsigned long safe_addr)
 	 * With either the component list or the certificate list
 	 * missing the kernel will stay ignorant of secure IPL.
 	 */
-	if (!comps || !certs)
-		return safe_addr;
+	if (!comps || !certs) {
+		certs = NULL;
+		return -1;
+	}
 
-	/*
-	 * Copy component and certificate list to a safe area
-	 * where the decompressed kernel can find them.
-	 */
-	safe_addr = find_bootdata_space(comps, certs, safe_addr);
-	copy_components_bootdata(comps);
-	copy_certificates_bootdata(certs);
+	ipl_report_needs_saving = true;
+	physmem_reserve(RR_IPLREPORT, (unsigned long)pl_hdr,
+			(unsigned long)rl_end - (unsigned long)pl_hdr);
+	return 0;
+}
+
+void save_ipl_cert_comp_list(void)
+{
+	unsigned long size;
+
+	if (!ipl_report_needs_saving)
+		return;
+
+	size = get_cert_comp_list_size();
+	early_ipl_comp_list_addr = physmem_alloc_top_down(RR_CERT_COMP_LIST, size, sizeof(int));
+	ipl_cert_list_addr = early_ipl_comp_list_addr + early_ipl_comp_list_size;
 
-	return safe_addr;
+	copy_components_bootdata();
+	copy_certificates_bootdata();
+	physmem_free(RR_IPLREPORT);
+	ipl_report_needs_saving = false;
 }
diff --git a/arch/s390/boot/kaslr.c b/arch/s390/boot/kaslr.c
index 3e3d846400b4..71f75f03f800 100644
--- a/arch/s390/boot/kaslr.c
+++ b/arch/s390/boot/kaslr.c
@@ -3,7 +3,7 @@
  * Copyright IBM Corp. 2019
  */
 #include <linux/pgtable.h>
-#include <asm/mem_detect.h>
+#include <asm/physmem_info.h>
 #include <asm/cpacf.h>
 #include <asm/timex.h>
 #include <asm/sclp.h>
@@ -91,113 +91,16 @@ static int get_random(unsigned long limit, unsigned long *value)
 	return 0;
 }
 
-/*
- * To randomize kernel base address we have to consider several facts:
- * 1. physical online memory might not be continuous and have holes. mem_detect
- *    info contains list of online memory ranges we should consider.
- * 2. we have several memory regions which are occupied and we should not
- *    overlap and destroy them. Currently safe_addr tells us the border below
- *    which all those occupied regions are. We are safe to use anything above
- *    safe_addr.
- * 3. the upper limit might apply as well, even if memory above that limit is
- *    online. Currently those limitations are:
- *    3.1. Limit set by "mem=" kernel command line option
- *    3.2. memory reserved at the end for kasan initialization.
- * 4. kernel base address must be aligned to THREAD_SIZE (kernel stack size).
- *    Which is required for CONFIG_CHECK_STACK. Currently THREAD_SIZE is 4 pages
- *    (16 pages when the kernel is built with kasan enabled)
- * Assumptions:
- * 1. kernel size (including .bss size) and upper memory limit are page aligned.
- * 2. mem_detect memory region start is THREAD_SIZE aligned / end is PAGE_SIZE
- *    aligned (in practice memory configurations granularity on z/VM and LPAR
- *    is 1mb).
- *
- * To guarantee uniform distribution of kernel base address among all suitable
- * addresses we generate random value just once. For that we need to build a
- * continuous range in which every value would be suitable. We can build this
- * range by simply counting all suitable addresses (let's call them positions)
- * which would be valid as kernel base address. To count positions we iterate
- * over online memory ranges. For each range which is big enough for the
- * kernel image we count all suitable addresses we can put the kernel image at
- * that is
- * (end - start - kernel_size) / THREAD_SIZE + 1
- * Two functions count_valid_kernel_positions and position_to_address help
- * to count positions in memory range given and then convert position back
- * to address.
- */
-static unsigned long count_valid_kernel_positions(unsigned long kernel_size,
-						  unsigned long _min,
-						  unsigned long _max)
-{
-	unsigned long start, end, pos = 0;
-	int i;
-
-	for_each_mem_detect_usable_block(i, &start, &end) {
-		if (_min >= end)
-			continue;
-		if (start >= _max)
-			break;
-		start = max(_min, start);
-		end = min(_max, end);
-		if (end - start < kernel_size)
-			continue;
-		pos += (end - start - kernel_size) / THREAD_SIZE + 1;
-	}
-
-	return pos;
-}
-
-static unsigned long position_to_address(unsigned long pos, unsigned long kernel_size,
-				 unsigned long _min, unsigned long _max)
-{
-	unsigned long start, end;
-	int i;
-
-	for_each_mem_detect_usable_block(i, &start, &end) {
-		if (_min >= end)
-			continue;
-		if (start >= _max)
-			break;
-		start = max(_min, start);
-		end = min(_max, end);
-		if (end - start < kernel_size)
-			continue;
-		if ((end - start - kernel_size) / THREAD_SIZE + 1 >= pos)
-			return start + (pos - 1) * THREAD_SIZE;
-		pos -= (end - start - kernel_size) / THREAD_SIZE + 1;
-	}
-
-	return 0;
-}
-
-unsigned long get_random_base(unsigned long safe_addr)
+unsigned long get_random_base(void)
 {
-	unsigned long usable_total = get_mem_detect_usable_total();
-	unsigned long memory_limit = get_mem_detect_end();
-	unsigned long base_pos, max_pos, kernel_size;
-	int i;
+	unsigned long vmlinux_size = vmlinux.image_size + vmlinux.bss_size;
+	unsigned long minimal_pos = vmlinux.default_lma + vmlinux_size;
+	unsigned long random;
 
-	/*
-	 * Avoid putting kernel in the end of physical memory
-	 * which vmem and kasan code will use for shadow memory and
-	 * pgtable mapping allocations.
-	 */
-	memory_limit -= kasan_estimate_memory_needs(usable_total);
-	memory_limit -= vmem_estimate_memory_needs(usable_total);
-
-	safe_addr = ALIGN(safe_addr, THREAD_SIZE);
-	kernel_size = vmlinux.image_size + vmlinux.bss_size;
-	if (safe_addr + kernel_size > memory_limit)
+	/* [vmlinux.default_lma + vmlinux.image_size + vmlinux.bss_size : physmem_info.usable] */
+	if (get_random(physmem_info.usable - minimal_pos, &random))
 		return 0;
 
-	max_pos = count_valid_kernel_positions(kernel_size, safe_addr, memory_limit);
-	if (!max_pos) {
-		sclp_early_printk("KASLR disabled: not enough memory\n");
-		return 0;
-	}
-
-	/* we need a value in the range [1, base_pos] inclusive */
-	if (get_random(max_pos, &base_pos))
-		return 0;
-	return position_to_address(base_pos + 1, kernel_size, safe_addr, memory_limit);
+	return physmem_alloc_range(RR_VMLINUX, vmlinux_size, THREAD_SIZE,
+				   vmlinux.default_lma, minimal_pos + random, false);
 }
diff --git a/arch/s390/boot/mem_detect.c b/arch/s390/boot/mem_detect.c
deleted file mode 100644
index 35f4ba11f7fd..000000000000
--- a/arch/s390/boot/mem_detect.c
+++ /dev/null
@@ -1,191 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-#include <linux/errno.h>
-#include <linux/init.h>
-#include <asm/setup.h>
-#include <asm/processor.h>
-#include <asm/sclp.h>
-#include <asm/sections.h>
-#include <asm/mem_detect.h>
-#include <asm/sparsemem.h>
-#include "decompressor.h"
-#include "boot.h"
-
-struct mem_detect_info __bootdata(mem_detect);
-
-/* up to 256 storage elements, 1020 subincrements each */
-#define ENTRIES_EXTENDED_MAX						       \
-	(256 * (1020 / 2) * sizeof(struct mem_detect_block))
-
-static struct mem_detect_block *__get_mem_detect_block_ptr(u32 n)
-{
-	if (n < MEM_INLINED_ENTRIES)
-		return &mem_detect.entries[n];
-	return &mem_detect.entries_extended[n - MEM_INLINED_ENTRIES];
-}
-
-/*
- * sequential calls to add_mem_detect_block with adjacent memory areas
- * are merged together into single memory block.
- */
-void add_mem_detect_block(u64 start, u64 end)
-{
-	struct mem_detect_block *block;
-
-	if (mem_detect.count) {
-		block = __get_mem_detect_block_ptr(mem_detect.count - 1);
-		if (block->end == start) {
-			block->end = end;
-			return;
-		}
-	}
-
-	block = __get_mem_detect_block_ptr(mem_detect.count);
-	block->start = start;
-	block->end = end;
-	mem_detect.count++;
-}
-
-static int __diag260(unsigned long rx1, unsigned long rx2)
-{
-	unsigned long reg1, reg2, ry;
-	union register_pair rx;
-	psw_t old;
-	int rc;
-
-	rx.even = rx1;
-	rx.odd	= rx2;
-	ry = 0x10; /* storage configuration */
-	rc = -1;   /* fail */
-	asm volatile(
-		"	mvc	0(16,%[psw_old]),0(%[psw_pgm])\n"
-		"	epsw	%[reg1],%[reg2]\n"
-		"	st	%[reg1],0(%[psw_pgm])\n"
-		"	st	%[reg2],4(%[psw_pgm])\n"
-		"	larl	%[reg1],1f\n"
-		"	stg	%[reg1],8(%[psw_pgm])\n"
-		"	diag	%[rx],%[ry],0x260\n"
-		"	ipm	%[rc]\n"
-		"	srl	%[rc],28\n"
-		"1:	mvc	0(16,%[psw_pgm]),0(%[psw_old])\n"
-		: [reg1] "=&d" (reg1),
-		  [reg2] "=&a" (reg2),
-		  [rc] "+&d" (rc),
-		  [ry] "+&d" (ry),
-		  "+Q" (S390_lowcore.program_new_psw),
-		  "=Q" (old)
-		: [rx] "d" (rx.pair),
-		  [psw_old] "a" (&old),
-		  [psw_pgm] "a" (&S390_lowcore.program_new_psw)
-		: "cc", "memory");
-	return rc == 0 ? ry : -1;
-}
-
-static int diag260(void)
-{
-	int rc, i;
-
-	struct {
-		unsigned long start;
-		unsigned long end;
-	} storage_extents[8] __aligned(16); /* VM supports up to 8 extends */
-
-	memset(storage_extents, 0, sizeof(storage_extents));
-	rc = __diag260((unsigned long)storage_extents, sizeof(storage_extents));
-	if (rc == -1)
-		return -1;
-
-	for (i = 0; i < min_t(int, rc, ARRAY_SIZE(storage_extents)); i++)
-		add_mem_detect_block(storage_extents[i].start, storage_extents[i].end + 1);
-	return 0;
-}
-
-static int tprot(unsigned long addr)
-{
-	unsigned long reg1, reg2;
-	int rc = -EFAULT;
-	psw_t old;
-
-	asm volatile(
-		"	mvc	0(16,%[psw_old]),0(%[psw_pgm])\n"
-		"	epsw	%[reg1],%[reg2]\n"
-		"	st	%[reg1],0(%[psw_pgm])\n"
-		"	st	%[reg2],4(%[psw_pgm])\n"
-		"	larl	%[reg1],1f\n"
-		"	stg	%[reg1],8(%[psw_pgm])\n"
-		"	tprot	0(%[addr]),0\n"
-		"	ipm	%[rc]\n"
-		"	srl	%[rc],28\n"
-		"1:	mvc	0(16,%[psw_pgm]),0(%[psw_old])\n"
-		: [reg1] "=&d" (reg1),
-		  [reg2] "=&a" (reg2),
-		  [rc] "+&d" (rc),
-		  "=Q" (S390_lowcore.program_new_psw.addr),
-		  "=Q" (old)
-		: [psw_old] "a" (&old),
-		  [psw_pgm] "a" (&S390_lowcore.program_new_psw),
-		  [addr] "a" (addr)
-		: "cc", "memory");
-	return rc;
-}
-
-static unsigned long search_mem_end(void)
-{
-	unsigned long range = 1 << (MAX_PHYSMEM_BITS - 20); /* in 1MB blocks */
-	unsigned long offset = 0;
-	unsigned long pivot;
-
-	while (range > 1) {
-		range >>= 1;
-		pivot = offset + range;
-		if (!tprot(pivot << 20))
-			offset = pivot;
-	}
-	return (offset + 1) << 20;
-}
-
-unsigned long detect_memory(unsigned long *safe_addr)
-{
-	unsigned long max_physmem_end = 0;
-
-	sclp_early_get_memsize(&max_physmem_end);
-	mem_detect.entries_extended = (struct mem_detect_block *)ALIGN(*safe_addr, sizeof(u64));
-
-	if (!sclp_early_read_storage_info()) {
-		mem_detect.info_source = MEM_DETECT_SCLP_STOR_INFO;
-	} else if (!diag260()) {
-		mem_detect.info_source = MEM_DETECT_DIAG260;
-		max_physmem_end = max_physmem_end ?: get_mem_detect_end();
-	} else if (max_physmem_end) {
-		add_mem_detect_block(0, max_physmem_end);
-		mem_detect.info_source = MEM_DETECT_SCLP_READ_INFO;
-	} else {
-		max_physmem_end = search_mem_end();
-		add_mem_detect_block(0, max_physmem_end);
-		mem_detect.info_source = MEM_DETECT_BIN_SEARCH;
-	}
-
-	if (mem_detect.count > MEM_INLINED_ENTRIES) {
-		*safe_addr += (mem_detect.count - MEM_INLINED_ENTRIES) *
-			     sizeof(struct mem_detect_block);
-	}
-
-	return max_physmem_end;
-}
-
-void mem_detect_set_usable_limit(unsigned long limit)
-{
-	struct mem_detect_block *block;
-	int i;
-
-	/* make sure mem_detect.usable ends up within online memory block */
-	for (i = 0; i < mem_detect.count; i++) {
-		block = __get_mem_detect_block_ptr(i);
-		if (block->start >= limit)
-			break;
-		if (block->end >= limit) {
-			mem_detect.usable = limit;
-			break;
-		}
-		mem_detect.usable = block->end;
-	}
-}
diff --git a/arch/s390/boot/pgm_check_info.c b/arch/s390/boot/pgm_check_info.c
index c2a1defc79da..0861e3c403f8 100644
--- a/arch/s390/boot/pgm_check_info.c
+++ b/arch/s390/boot/pgm_check_info.c
@@ -123,11 +123,10 @@ out:
 	sclp_early_printk(buf);
 }
 
-static noinline void print_stacktrace(void)
+void print_stacktrace(unsigned long sp)
 {
 	struct stack_info boot_stack = { STACK_TYPE_TASK, (unsigned long)_stack_start,
 					 (unsigned long)_stack_end };
-	unsigned long sp = S390_lowcore.gpregs_save_area[15];
 	bool first = true;
 
 	decompressor_printk("Call Trace:\n");
@@ -173,7 +172,7 @@ void print_pgm_check_info(void)
 			    gpregs[8], gpregs[9], gpregs[10], gpregs[11]);
 	decompressor_printk("      %016lx %016lx %016lx %016lx\n",
 			    gpregs[12], gpregs[13], gpregs[14], gpregs[15]);
-	print_stacktrace();
+	print_stacktrace(S390_lowcore.gpregs_save_area[15]);
 	decompressor_printk("Last Breaking-Event-Address:\n");
 	decompressor_printk(" [<%016lx>] %pS\n", (unsigned long)S390_lowcore.pgm_last_break,
 			    (void *)S390_lowcore.pgm_last_break);
diff --git a/arch/s390/boot/physmem_info.c b/arch/s390/boot/physmem_info.c
new file mode 100644
index 000000000000..4ee9b7381142
--- /dev/null
+++ b/arch/s390/boot/physmem_info.c
@@ -0,0 +1,323 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/processor.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <asm/physmem_info.h>
+#include <asm/stacktrace.h>
+#include <asm/boot_data.h>
+#include <asm/sparsemem.h>
+#include <asm/sections.h>
+#include <asm/setup.h>
+#include <asm/sclp.h>
+#include <asm/uv.h>
+#include "decompressor.h"
+#include "boot.h"
+
+struct physmem_info __bootdata(physmem_info);
+static unsigned int physmem_alloc_ranges;
+static unsigned long physmem_alloc_pos;
+
+/* up to 256 storage elements, 1020 subincrements each */
+#define ENTRIES_EXTENDED_MAX						       \
+	(256 * (1020 / 2) * sizeof(struct physmem_range))
+
+static struct physmem_range *__get_physmem_range_ptr(u32 n)
+{
+	if (n < MEM_INLINED_ENTRIES)
+		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,
+			physmem_alloc_pos, true);
+	}
+	return &physmem_info.online_extended[n - MEM_INLINED_ENTRIES];
+}
+
+/*
+ * sequential calls to add_physmem_online_range with adjacent memory ranges
+ * are merged together into single memory range.
+ */
+void add_physmem_online_range(u64 start, u64 end)
+{
+	struct physmem_range *range;
+
+	if (physmem_info.range_count) {
+		range = __get_physmem_range_ptr(physmem_info.range_count - 1);
+		if (range->end == start) {
+			range->end = end;
+			return;
+		}
+	}
+
+	range = __get_physmem_range_ptr(physmem_info.range_count);
+	range->start = start;
+	range->end = end;
+	physmem_info.range_count++;
+}
+
+static int __diag260(unsigned long rx1, unsigned long rx2)
+{
+	unsigned long reg1, reg2, ry;
+	union register_pair rx;
+	psw_t old;
+	int rc;
+
+	rx.even = rx1;
+	rx.odd	= rx2;
+	ry = 0x10; /* storage configuration */
+	rc = -1;   /* fail */
+	asm volatile(
+		"	mvc	0(16,%[psw_old]),0(%[psw_pgm])\n"
+		"	epsw	%[reg1],%[reg2]\n"
+		"	st	%[reg1],0(%[psw_pgm])\n"
+		"	st	%[reg2],4(%[psw_pgm])\n"
+		"	larl	%[reg1],1f\n"
+		"	stg	%[reg1],8(%[psw_pgm])\n"
+		"	diag	%[rx],%[ry],0x260\n"
+		"	ipm	%[rc]\n"
+		"	srl	%[rc],28\n"
+		"1:	mvc	0(16,%[psw_pgm]),0(%[psw_old])\n"
+		: [reg1] "=&d" (reg1),
+		  [reg2] "=&a" (reg2),
+		  [rc] "+&d" (rc),
+		  [ry] "+&d" (ry),
+		  "+Q" (S390_lowcore.program_new_psw),
+		  "=Q" (old)
+		: [rx] "d" (rx.pair),
+		  [psw_old] "a" (&old),
+		  [psw_pgm] "a" (&S390_lowcore.program_new_psw)
+		: "cc", "memory");
+	return rc == 0 ? ry : -1;
+}
+
+static int diag260(void)
+{
+	int rc, i;
+
+	struct {
+		unsigned long start;
+		unsigned long end;
+	} storage_extents[8] __aligned(16); /* VM supports up to 8 extends */
+
+	memset(storage_extents, 0, sizeof(storage_extents));
+	rc = __diag260((unsigned long)storage_extents, sizeof(storage_extents));
+	if (rc == -1)
+		return -1;
+
+	for (i = 0; i < min_t(int, rc, ARRAY_SIZE(storage_extents)); i++)
+		add_physmem_online_range(storage_extents[i].start, storage_extents[i].end + 1);
+	return 0;
+}
+
+static int tprot(unsigned long addr)
+{
+	unsigned long reg1, reg2;
+	int rc = -EFAULT;
+	psw_t old;
+
+	asm volatile(
+		"	mvc	0(16,%[psw_old]),0(%[psw_pgm])\n"
+		"	epsw	%[reg1],%[reg2]\n"
+		"	st	%[reg1],0(%[psw_pgm])\n"
+		"	st	%[reg2],4(%[psw_pgm])\n"
+		"	larl	%[reg1],1f\n"
+		"	stg	%[reg1],8(%[psw_pgm])\n"
+		"	tprot	0(%[addr]),0\n"
+		"	ipm	%[rc]\n"
+		"	srl	%[rc],28\n"
+		"1:	mvc	0(16,%[psw_pgm]),0(%[psw_old])\n"
+		: [reg1] "=&d" (reg1),
+		  [reg2] "=&a" (reg2),
+		  [rc] "+&d" (rc),
+		  "=Q" (S390_lowcore.program_new_psw.addr),
+		  "=Q" (old)
+		: [psw_old] "a" (&old),
+		  [psw_pgm] "a" (&S390_lowcore.program_new_psw),
+		  [addr] "a" (addr)
+		: "cc", "memory");
+	return rc;
+}
+
+static unsigned long search_mem_end(void)
+{
+	unsigned long range = 1 << (MAX_PHYSMEM_BITS - 20); /* in 1MB blocks */
+	unsigned long offset = 0;
+	unsigned long pivot;
+
+	while (range > 1) {
+		range >>= 1;
+		pivot = offset + range;
+		if (!tprot(pivot << 20))
+			offset = pivot;
+	}
+	return (offset + 1) << 20;
+}
+
+unsigned long detect_max_physmem_end(void)
+{
+	unsigned long max_physmem_end = 0;
+
+	if (!sclp_early_get_memsize(&max_physmem_end)) {
+		physmem_info.info_source = MEM_DETECT_SCLP_READ_INFO;
+	} else {
+		max_physmem_end = search_mem_end();
+		physmem_info.info_source = MEM_DETECT_BIN_SEARCH;
+	}
+	return max_physmem_end;
+}
+
+void detect_physmem_online_ranges(unsigned long max_physmem_end)
+{
+	if (!sclp_early_read_storage_info()) {
+		physmem_info.info_source = MEM_DETECT_SCLP_STOR_INFO;
+	} else if (!diag260()) {
+		physmem_info.info_source = MEM_DETECT_DIAG260;
+	} else if (max_physmem_end) {
+		add_physmem_online_range(0, max_physmem_end);
+	}
+}
+
+void physmem_set_usable_limit(unsigned long limit)
+{
+	physmem_info.usable = limit;
+	physmem_alloc_pos = limit;
+}
+
+static void die_oom(unsigned long size, unsigned long align, unsigned long min, unsigned long max)
+{
+	unsigned long start, end, total_mem = 0, total_reserved_mem = 0;
+	struct reserved_range *range;
+	enum reserved_range_type t;
+	int i;
+
+	decompressor_printk("Linux version %s\n", kernel_version);
+	if (!is_prot_virt_guest() && early_command_line[0])
+		decompressor_printk("Kernel command line: %s\n", early_command_line);
+	decompressor_printk("Out of memory allocating %lx bytes %lx aligned in range %lx:%lx\n",
+			    size, align, min, max);
+	decompressor_printk("Reserved memory ranges:\n");
+	for_each_physmem_reserved_range(t, range, &start, &end) {
+		decompressor_printk("%016lx %016lx %s\n", start, end, get_rr_type_name(t));
+		total_reserved_mem += end - start;
+	}
+	decompressor_printk("Usable online memory ranges (info source: %s [%x]):\n",
+			    get_physmem_info_source(), physmem_info.info_source);
+	for_each_physmem_usable_range(i, &start, &end) {
+		decompressor_printk("%016lx %016lx\n", start, end);
+		total_mem += end - start;
+	}
+	decompressor_printk("Usable online memory total: %lx Reserved: %lx Free: %lx\n",
+			    total_mem, total_reserved_mem,
+			    total_mem > total_reserved_mem ? total_mem - total_reserved_mem : 0);
+	print_stacktrace(current_frame_address());
+	sclp_early_printk("\n\n -- System halted\n");
+	disabled_wait();
+}
+
+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_free(enum reserved_range_type type)
+{
+	physmem_info.reserved[type].start = 0;
+	physmem_info.reserved[type].end = 0;
+}
+
+static bool __physmem_alloc_intersects(unsigned long addr, unsigned long size,
+				       unsigned long *intersection_start)
+{
+	unsigned long res_addr, res_size;
+	int t;
+
+	for (t = 0; t < RR_MAX; t++) {
+		if (!get_physmem_reserved(t, &res_addr, &res_size))
+			continue;
+		if (intersects(addr, size, res_addr, res_size)) {
+			*intersection_start = res_addr;
+			return true;
+		}
+	}
+	return ipl_report_certs_intersects(addr, size, intersection_start);
+}
+
+static unsigned long __physmem_alloc_range(unsigned long size, unsigned long align,
+					   unsigned long min, unsigned long max,
+					   unsigned int from_ranges, unsigned int *ranges_left,
+					   bool die_on_oom)
+{
+	unsigned int nranges = from_ranges ?: physmem_info.range_count;
+	unsigned long range_start, range_end;
+	unsigned long intersection_start;
+	unsigned long addr, pos = max;
+
+	align = max(align, 8UL);
+	while (nranges) {
+		__get_physmem_range(nranges - 1, &range_start, &range_end, false);
+		pos = min(range_end, pos);
+
+		if (round_up(min, align) + size > pos)
+			break;
+		addr = round_down(pos - size, align);
+		if (range_start > addr) {
+			nranges--;
+			continue;
+		}
+		if (__physmem_alloc_intersects(addr, size, &intersection_start)) {
+			pos = intersection_start;
+			continue;
+		}
+
+		if (ranges_left)
+			*ranges_left = nranges;
+		return addr;
+	}
+	if (die_on_oom)
+		die_oom(size, align, min, max);
+	return 0;
+}
+
+unsigned long physmem_alloc_range(enum reserved_range_type type, unsigned long size,
+				  unsigned long align, unsigned long min, unsigned long max,
+				  bool die_on_oom)
+{
+	unsigned long addr;
+
+	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);
+	return addr;
+}
+
+unsigned long physmem_alloc_top_down(enum reserved_range_type type, unsigned long size,
+				     unsigned long align)
+{
+	struct reserved_range *range = &physmem_info.reserved[type];
+	struct reserved_range *new_range;
+	unsigned int ranges_left;
+	unsigned long addr;
+
+	addr = __physmem_alloc_range(size, align, 0, physmem_alloc_pos, physmem_alloc_ranges,
+				     &ranges_left, true);
+	/* if not a consecutive allocation of the same type or first allocation */
+	if (range->start != addr + size) {
+		if (range->end) {
+			physmem_alloc_pos = __physmem_alloc_range(
+				sizeof(struct reserved_range), 0, 0, physmem_alloc_pos,
+				physmem_alloc_ranges, &ranges_left, true);
+			new_range = (struct reserved_range *)physmem_alloc_pos;
+			*new_range = *range;
+			range->chain = new_range;
+			addr = __physmem_alloc_range(size, align, 0, physmem_alloc_pos,
+						     ranges_left, &ranges_left, true);
+		}
+		range->end = addr + size;
+	}
+	range->start = addr;
+	physmem_alloc_pos = addr;
+	physmem_alloc_ranges = ranges_left;
+	return addr;
+}
diff --git a/arch/s390/boot/startup.c b/arch/s390/boot/startup.c
index 11413f0baabc..bdf305a93987 100644
--- a/arch/s390/boot/startup.c
+++ b/arch/s390/boot/startup.c
@@ -12,7 +12,7 @@
 #include <asm/diag.h>
 #include <asm/uv.h>
 #include <asm/abs_lowcore.h>
-#include <asm/mem_detect.h>
+#include <asm/physmem_info.h>
 #include "decompressor.h"
 #include "boot.h"
 #include "uv.h"
@@ -21,7 +21,6 @@ unsigned long __bootdata_preserved(__kaslr_offset);
 unsigned long __bootdata_preserved(__abs_lowcore);
 unsigned long __bootdata_preserved(__memcpy_real_area);
 pte_t *__bootdata_preserved(memcpy_real_ptep);
-unsigned long __bootdata(__amode31_base);
 unsigned long __bootdata_preserved(VMALLOC_START);
 unsigned long __bootdata_preserved(VMALLOC_END);
 struct page *__bootdata_preserved(vmemmap);
@@ -29,8 +28,6 @@ unsigned long __bootdata_preserved(vmemmap_size);
 unsigned long __bootdata_preserved(MODULES_VADDR);
 unsigned long __bootdata_preserved(MODULES_END);
 unsigned long __bootdata(ident_map_size);
-int __bootdata(is_full_image) = 1;
-struct initrd_data __bootdata(initrd_data);
 
 u64 __bootdata_preserved(stfle_fac_list[16]);
 u64 __bootdata_preserved(alt_stfle_fac_list[16]);
@@ -76,17 +73,20 @@ unsigned long mem_safe_offset(void)
 }
 #endif
 
-static unsigned long rescue_initrd(unsigned long safe_addr)
+static void rescue_initrd(unsigned long min, unsigned long max)
 {
+	unsigned long old_addr, addr, size;
+
 	if (!IS_ENABLED(CONFIG_BLK_DEV_INITRD))
-		return safe_addr;
-	if (!initrd_data.start || !initrd_data.size)
-		return safe_addr;
-	if (initrd_data.start < safe_addr) {
-		memmove((void *)safe_addr, (void *)initrd_data.start, initrd_data.size);
-		initrd_data.start = safe_addr;
-	}
-	return initrd_data.start + initrd_data.size;
+		return;
+	if (!get_physmem_reserved(RR_INITRD, &addr, &size))
+		return;
+	if (addr >= min && addr + size <= max)
+		return;
+	old_addr = addr;
+	physmem_free(RR_INITRD);
+	addr = physmem_alloc_top_down(RR_INITRD, size, 0);
+	memmove((void *)addr, (void *)old_addr, size);
 }
 
 static void copy_bootdata(void)
@@ -140,7 +140,7 @@ static void handle_relocs(unsigned long offset)
  *
  * Consider the following factors:
  * 1. max_physmem_end - end of physical memory online or standby.
- *    Always <= end of the last online memory block (get_mem_detect_end()).
+ *    Always >= end of the last online memory range (get_physmem_online_end()).
  * 2. CONFIG_MAX_PHYSMEM_BITS - the maximum size of physical memory the
  *    kernel is able to support.
  * 3. "mem=" kernel command line option which limits physical memory usage.
@@ -266,48 +266,57 @@ static void offset_vmlinux_info(unsigned long offset)
 	vmlinux.init_mm_off += offset;
 	vmlinux.swapper_pg_dir_off += offset;
 	vmlinux.invalid_pg_dir_off += offset;
-}
-
-static unsigned long reserve_amode31(unsigned long safe_addr)
-{
-	__amode31_base = PAGE_ALIGN(safe_addr);
-	return __amode31_base + vmlinux.amode31_size;
+#ifdef CONFIG_KASAN
+	vmlinux.kasan_early_shadow_page_off += offset;
+	vmlinux.kasan_early_shadow_pte_off += offset;
+	vmlinux.kasan_early_shadow_pmd_off += offset;
+	vmlinux.kasan_early_shadow_pud_off += offset;
+	vmlinux.kasan_early_shadow_p4d_off += offset;
+#endif
 }
 
 void startup_kernel(void)
 {
 	unsigned long max_physmem_end;
 	unsigned long random_lma;
-	unsigned long safe_addr;
 	unsigned long asce_limit;
+	unsigned long safe_addr;
 	void *img;
 	psw_t psw;
 
-	initrd_data.start = parmarea.initrd_start;
-	initrd_data.size = parmarea.initrd_size;
+	setup_lpp();
+	safe_addr = mem_safe_offset();
+	/*
+	 * reserve decompressor memory together with decompression heap, buffer and
+	 * memory which might be occupied by uncompressed kernel at default 1Mb
+	 * position (if KASLR is off or failed).
+	 */
+	physmem_reserve(RR_DECOMPRESSOR, 0, safe_addr);
+	if (IS_ENABLED(CONFIG_BLK_DEV_INITRD) && parmarea.initrd_size)
+		physmem_reserve(RR_INITRD, parmarea.initrd_start, parmarea.initrd_size);
 	oldmem_data.start = parmarea.oldmem_base;
 	oldmem_data.size = parmarea.oldmem_size;
 
-	setup_lpp();
 	store_ipl_parmblock();
-	safe_addr = mem_safe_offset();
-	safe_addr = reserve_amode31(safe_addr);
-	safe_addr = read_ipl_report(safe_addr);
+	read_ipl_report();
 	uv_query_info();
-	safe_addr = rescue_initrd(safe_addr);
 	sclp_early_read_info();
 	setup_boot_command_line();
 	parse_boot_command_line();
 	detect_facilities();
 	sanitize_prot_virt_host();
-	max_physmem_end = detect_memory(&safe_addr);
+	max_physmem_end = detect_max_physmem_end();
 	setup_ident_map_size(max_physmem_end);
 	setup_vmalloc_size();
 	asce_limit = setup_kernel_memory_layout();
-	mem_detect_set_usable_limit(ident_map_size);
+	/* got final ident_map_size, physmem allocations could be performed now */
+	physmem_set_usable_limit(ident_map_size);
+	detect_physmem_online_ranges(max_physmem_end);
+	save_ipl_cert_comp_list();
+	rescue_initrd(safe_addr, ident_map_size);
 
 	if (IS_ENABLED(CONFIG_RANDOMIZE_BASE) && kaslr_enabled) {
-		random_lma = get_random_base(safe_addr);
+		random_lma = get_random_base();
 		if (random_lma) {
 			__kaslr_offset = random_lma - vmlinux.default_lma;
 			img = (void *)vmlinux.default_lma;
@@ -318,8 +327,16 @@ void startup_kernel(void)
 	if (!IS_ENABLED(CONFIG_KERNEL_UNCOMPRESSED)) {
 		img = decompress_kernel();
 		memmove((void *)vmlinux.default_lma, img, vmlinux.image_size);
-	} else if (__kaslr_offset)
+	} else if (__kaslr_offset) {
 		memcpy((void *)vmlinux.default_lma, img, vmlinux.image_size);
+		memset(img, 0, vmlinux.image_size);
+	}
+
+	/* vmlinux decompression is done, shrink reserved low memory */
+	physmem_reserve(RR_DECOMPRESSOR, 0, (unsigned long)_decompressor_end);
+	if (!__kaslr_offset)
+		physmem_reserve(RR_VMLINUX, vmlinux.default_lma, vmlinux.image_size + vmlinux.bss_size);
+	physmem_alloc_range(RR_AMODE31, vmlinux.amode31_size, PAGE_SIZE, 0, SZ_2G, true);
 
 	/*
 	 * The order of the following operations is important:
@@ -339,16 +356,11 @@ void startup_kernel(void)
 	setup_vmem(asce_limit);
 	copy_bootdata();
 
-	if (__kaslr_offset) {
-		/*
-		 * Save KASLR offset for early dumps, before vmcore_info is set.
-		 * Mark as uneven to distinguish from real vmcore_info pointer.
-		 */
-		S390_lowcore.vmcore_info = __kaslr_offset | 0x1UL;
-		/* Clear non-relocated kernel */
-		if (IS_ENABLED(CONFIG_KERNEL_UNCOMPRESSED))
-			memset(img, 0, vmlinux.image_size);
-	}
+	/*
+	 * Save KASLR offset for early dumps, before vmcore_info is set.
+	 * Mark as uneven to distinguish from real vmcore_info pointer.
+	 */
+	S390_lowcore.vmcore_info = __kaslr_offset ? __kaslr_offset | 0x1UL : 0;
 
 	/*
 	 * Jump to the decompressed kernel entry point and switch DAT mode on.
diff --git a/arch/s390/boot/vmem.c b/arch/s390/boot/vmem.c
index 4d1d0d8e99cb..b01ea2abda03 100644
--- a/arch/s390/boot/vmem.c
+++ b/arch/s390/boot/vmem.c
@@ -1,81 +1,213 @@
 // SPDX-License-Identifier: GPL-2.0
 #include <linux/sched/task.h>
 #include <linux/pgtable.h>
+#include <linux/kasan.h>
 #include <asm/pgalloc.h>
 #include <asm/facility.h>
 #include <asm/sections.h>
-#include <asm/mem_detect.h>
+#include <asm/physmem_info.h>
 #include <asm/maccess.h>
 #include <asm/abs_lowcore.h>
 #include "decompressor.h"
 #include "boot.h"
 
+unsigned long __bootdata_preserved(s390_invalid_asce);
+
 #define init_mm			(*(struct mm_struct *)vmlinux.init_mm_off)
 #define swapper_pg_dir		vmlinux.swapper_pg_dir_off
 #define invalid_pg_dir		vmlinux.invalid_pg_dir_off
 
-/*
- * Mimic virt_to_kpte() in lack of init_mm symbol. Skip pmd NULL check though.
- */
-static inline pte_t *__virt_to_kpte(unsigned long va)
-{
-	return pte_offset_kernel(pmd_offset(pud_offset(p4d_offset(pgd_offset_k(va), va), va), va), va);
-}
-
-unsigned long __bootdata_preserved(s390_invalid_asce);
-unsigned long __bootdata(pgalloc_pos);
-unsigned long __bootdata(pgalloc_end);
-unsigned long __bootdata(pgalloc_low);
-
 enum populate_mode {
 	POPULATE_NONE,
 	POPULATE_ONE2ONE,
 	POPULATE_ABS_LOWCORE,
+#ifdef CONFIG_KASAN
+	POPULATE_KASAN_MAP_SHADOW,
+	POPULATE_KASAN_ZERO_SHADOW,
+	POPULATE_KASAN_SHALLOW
+#endif
 };
 
-static void boot_check_oom(void)
+static void pgtable_populate(unsigned long addr, unsigned long end, enum populate_mode mode);
+
+#ifdef CONFIG_KASAN
+
+#define kasan_early_shadow_page	vmlinux.kasan_early_shadow_page_off
+#define kasan_early_shadow_pte	((pte_t *)vmlinux.kasan_early_shadow_pte_off)
+#define kasan_early_shadow_pmd	((pmd_t *)vmlinux.kasan_early_shadow_pmd_off)
+#define kasan_early_shadow_pud	((pud_t *)vmlinux.kasan_early_shadow_pud_off)
+#define kasan_early_shadow_p4d	((p4d_t *)vmlinux.kasan_early_shadow_p4d_off)
+#define __sha(x)		((unsigned long)kasan_mem_to_shadow((void *)x))
+
+static pte_t pte_z;
+
+static void kasan_populate_shadow(void)
+{
+	pmd_t pmd_z = __pmd(__pa(kasan_early_shadow_pte) | _SEGMENT_ENTRY);
+	pud_t pud_z = __pud(__pa(kasan_early_shadow_pmd) | _REGION3_ENTRY);
+	p4d_t p4d_z = __p4d(__pa(kasan_early_shadow_pud) | _REGION2_ENTRY);
+	unsigned long untracked_end;
+	unsigned long start, end;
+	int i;
+
+	pte_z = __pte(__pa(kasan_early_shadow_page) | pgprot_val(PAGE_KERNEL_RO));
+	if (!machine.has_nx)
+		pte_z = clear_pte_bit(pte_z, __pgprot(_PAGE_NOEXEC));
+	crst_table_init((unsigned long *)kasan_early_shadow_p4d, p4d_val(p4d_z));
+	crst_table_init((unsigned long *)kasan_early_shadow_pud, pud_val(pud_z));
+	crst_table_init((unsigned long *)kasan_early_shadow_pmd, pmd_val(pmd_z));
+	memset64((u64 *)kasan_early_shadow_pte, pte_val(pte_z), PTRS_PER_PTE);
+
+	/*
+	 * Current memory layout:
+	 * +- 0 -------------+	       +- shadow start -+
+	 * |1:1 ident mapping|	      /|1/8 of ident map|
+	 * |		     |	     / |		|
+	 * +-end of ident map+	    /  +----------------+
+	 * | ... gap ...     |	   /   |    kasan	|
+	 * |		     |	  /    |  zero page	|
+	 * +- vmalloc area  -+	 /     |   mapping	|
+	 * | vmalloc_size    |	/      | (untracked)	|
+	 * +- modules vaddr -+ /       +----------------+
+	 * | 2Gb	     |/        |    unmapped	| allocated per module
+	 * +- shadow start  -+	       +----------------+
+	 * | 1/8 addr space  |	       | zero pg mapping| (untracked)
+	 * +- shadow end ----+---------+- shadow end ---+
+	 *
+	 * Current memory layout (KASAN_VMALLOC):
+	 * +- 0 -------------+	       +- shadow start -+
+	 * |1:1 ident mapping|	      /|1/8 of ident map|
+	 * |		     |	     / |		|
+	 * +-end of ident map+	    /  +----------------+
+	 * | ... gap ...     |	   /   | kasan zero page| (untracked)
+	 * |		     |	  /    | mapping	|
+	 * +- vmalloc area  -+	 /     +----------------+
+	 * | vmalloc_size    |	/      |shallow populate|
+	 * +- modules vaddr -+ /       +----------------+
+	 * | 2Gb	     |/        |shallow populate|
+	 * +- shadow start  -+	       +----------------+
+	 * | 1/8 addr space  |	       | zero pg mapping| (untracked)
+	 * +- shadow end ----+---------+- shadow end ---+
+	 */
+
+	for_each_physmem_usable_range(i, &start, &end)
+		pgtable_populate(__sha(start), __sha(end), POPULATE_KASAN_MAP_SHADOW);
+	if (IS_ENABLED(CONFIG_KASAN_VMALLOC)) {
+		untracked_end = VMALLOC_START;
+		/* shallowly populate kasan shadow for vmalloc and modules */
+		pgtable_populate(__sha(VMALLOC_START), __sha(MODULES_END), POPULATE_KASAN_SHALLOW);
+	} else {
+		untracked_end = MODULES_VADDR;
+	}
+	/* populate kasan shadow for untracked memory */
+	pgtable_populate(__sha(ident_map_size), __sha(untracked_end), POPULATE_KASAN_ZERO_SHADOW);
+	pgtable_populate(__sha(MODULES_END), __sha(_REGION1_SIZE), POPULATE_KASAN_ZERO_SHADOW);
+}
+
+static bool kasan_pgd_populate_zero_shadow(pgd_t *pgd, unsigned long addr,
+					   unsigned long end, enum populate_mode mode)
+{
+	if (mode == POPULATE_KASAN_ZERO_SHADOW &&
+	    IS_ALIGNED(addr, PGDIR_SIZE) && end - addr >= PGDIR_SIZE) {
+		pgd_populate(&init_mm, pgd, kasan_early_shadow_p4d);
+		return true;
+	}
+	return false;
+}
+
+static bool kasan_p4d_populate_zero_shadow(p4d_t *p4d, unsigned long addr,
+					   unsigned long end, enum populate_mode mode)
+{
+	if (mode == POPULATE_KASAN_ZERO_SHADOW &&
+	    IS_ALIGNED(addr, P4D_SIZE) && end - addr >= P4D_SIZE) {
+		p4d_populate(&init_mm, p4d, kasan_early_shadow_pud);
+		return true;
+	}
+	return false;
+}
+
+static bool kasan_pud_populate_zero_shadow(pud_t *pud, unsigned long addr,
+					   unsigned long end, enum populate_mode mode)
+{
+	if (mode == POPULATE_KASAN_ZERO_SHADOW &&
+	    IS_ALIGNED(addr, PUD_SIZE) && end - addr >= PUD_SIZE) {
+		pud_populate(&init_mm, pud, kasan_early_shadow_pmd);
+		return true;
+	}
+	return false;
+}
+
+static bool kasan_pmd_populate_zero_shadow(pmd_t *pmd, unsigned long addr,
+					   unsigned long end, enum populate_mode mode)
 {
-	if (pgalloc_pos < pgalloc_low)
-		error("out of memory on boot\n");
+	if (mode == POPULATE_KASAN_ZERO_SHADOW &&
+	    IS_ALIGNED(addr, PMD_SIZE) && end - addr >= PMD_SIZE) {
+		pmd_populate(&init_mm, pmd, kasan_early_shadow_pte);
+		return true;
+	}
+	return false;
 }
 
-static void pgtable_populate_init(void)
+static bool kasan_pte_populate_zero_shadow(pte_t *pte, enum populate_mode mode)
 {
-	unsigned long initrd_end;
-	unsigned long kernel_end;
-
-	kernel_end = vmlinux.default_lma + vmlinux.image_size + vmlinux.bss_size;
-	pgalloc_low = round_up(kernel_end, PAGE_SIZE);
-	if (IS_ENABLED(CONFIG_BLK_DEV_INITRD)) {
-		initrd_end =  round_up(initrd_data.start + initrd_data.size, _SEGMENT_SIZE);
-		pgalloc_low = max(pgalloc_low, initrd_end);
+	pte_t entry;
+
+	if (mode == POPULATE_KASAN_ZERO_SHADOW) {
+		set_pte(pte, pte_z);
+		return true;
 	}
+	return false;
+}
+#else
 
-	pgalloc_end = round_down(get_mem_detect_end(), PAGE_SIZE);
-	pgalloc_pos = pgalloc_end;
+static inline void kasan_populate_shadow(void) {}
 
-	boot_check_oom();
+static inline bool kasan_pgd_populate_zero_shadow(pgd_t *pgd, unsigned long addr,
+						  unsigned long end, enum populate_mode mode)
+{
+	return false;
 }
 
-static void *boot_alloc_pages(unsigned int order)
+static inline bool kasan_p4d_populate_zero_shadow(p4d_t *p4d, unsigned long addr,
+						  unsigned long end, enum populate_mode mode)
 {
-	unsigned long size = PAGE_SIZE << order;
+	return false;
+}
 
-	pgalloc_pos -= size;
-	pgalloc_pos = round_down(pgalloc_pos, size);
+static inline bool kasan_pud_populate_zero_shadow(pud_t *pud, unsigned long addr,
+						  unsigned long end, enum populate_mode mode)
+{
+	return false;
+}
 
-	boot_check_oom();
+static inline bool kasan_pmd_populate_zero_shadow(pmd_t *pmd, unsigned long addr,
+						  unsigned long end, enum populate_mode mode)
+{
+	return false;
+}
+
+static bool kasan_pte_populate_zero_shadow(pte_t *pte, enum populate_mode mode)
+{
+	return false;
+}
+
+#endif
 
-	return (void *)pgalloc_pos;
+/*
+ * Mimic virt_to_kpte() in lack of init_mm symbol. Skip pmd NULL check though.
+ */
+static inline pte_t *__virt_to_kpte(unsigned long va)
+{
+	return pte_offset_kernel(pmd_offset(pud_offset(p4d_offset(pgd_offset_k(va), va), va), va), va);
 }
 
 static void *boot_crst_alloc(unsigned long val)
 {
+	unsigned long size = PAGE_SIZE << CRST_ALLOC_ORDER;
 	unsigned long *table;
 
-	table = boot_alloc_pages(CRST_ALLOC_ORDER);
-	if (table)
-		crst_table_init(table, val);
+	table = (unsigned long *)physmem_alloc_top_down(RR_VMEM, size, size);
+	crst_table_init(table, val);
 	return table;
 }
 
@@ -84,20 +216,23 @@ static pte_t *boot_pte_alloc(void)
 	static void *pte_leftover;
 	pte_t *pte;
 
-	BUILD_BUG_ON(_PAGE_TABLE_SIZE * 2 != PAGE_SIZE);
-
+	/*
+	 * handling pte_leftovers this way helps to avoid memory fragmentation
+	 * during POPULATE_KASAN_MAP_SHADOW when EDAT is off
+	 */
 	if (!pte_leftover) {
-		pte_leftover = boot_alloc_pages(0);
+		pte_leftover = (void *)physmem_alloc_top_down(RR_VMEM, PAGE_SIZE, PAGE_SIZE);
 		pte = pte_leftover + _PAGE_TABLE_SIZE;
 	} else {
 		pte = pte_leftover;
 		pte_leftover = NULL;
 	}
+
 	memset64((u64 *)pte, _PAGE_INVALID, PTRS_PER_PTE);
 	return pte;
 }
 
-static unsigned long _pa(unsigned long addr, enum populate_mode mode)
+static unsigned long _pa(unsigned long addr, unsigned long size, enum populate_mode mode)
 {
 	switch (mode) {
 	case POPULATE_NONE:
@@ -106,6 +241,12 @@ static unsigned long _pa(unsigned long addr, enum populate_mode mode)
 		return addr;
 	case POPULATE_ABS_LOWCORE:
 		return __abs_lowcore_pa(addr);
+#ifdef CONFIG_KASAN
+	case POPULATE_KASAN_MAP_SHADOW:
+		addr = physmem_alloc_top_down(RR_VMEM, size, size);
+		memset((void *)addr, 0, size);
+		return addr;
+#endif
 	default:
 		return -1;
 	}
@@ -126,13 +267,14 @@ static bool can_large_pmd(pmd_t *pm_dir, unsigned long addr, unsigned long end)
 static void pgtable_pte_populate(pmd_t *pmd, unsigned long addr, unsigned long end,
 				 enum populate_mode mode)
 {
-	unsigned long next;
 	pte_t *pte, entry;
 
 	pte = pte_offset_kernel(pmd, addr);
 	for (; addr < end; addr += PAGE_SIZE, pte++) {
 		if (pte_none(*pte)) {
-			entry = __pte(_pa(addr, mode));
+			if (kasan_pte_populate_zero_shadow(pte, mode))
+				continue;
+			entry = __pte(_pa(addr, PAGE_SIZE, mode));
 			entry = set_pte_bit(entry, PAGE_KERNEL_EXEC);
 			set_pte(pte, entry);
 		}
@@ -150,8 +292,10 @@ static void pgtable_pmd_populate(pud_t *pud, unsigned long addr, unsigned long e
 	for (; addr < end; addr = next, pmd++) {
 		next = pmd_addr_end(addr, end);
 		if (pmd_none(*pmd)) {
+			if (kasan_pmd_populate_zero_shadow(pmd, addr, next, mode))
+				continue;
 			if (can_large_pmd(pmd, addr, next)) {
-				entry = __pmd(_pa(addr, mode));
+				entry = __pmd(_pa(addr, _SEGMENT_SIZE, mode));
 				entry = set_pmd_bit(entry, SEGMENT_KERNEL_EXEC);
 				set_pmd(pmd, entry);
 				continue;
@@ -176,8 +320,10 @@ static void pgtable_pud_populate(p4d_t *p4d, unsigned long addr, unsigned long e
 	for (; addr < end; addr = next, pud++) {
 		next = pud_addr_end(addr, end);
 		if (pud_none(*pud)) {
+			if (kasan_pud_populate_zero_shadow(pud, addr, next, mode))
+				continue;
 			if (can_large_pud(pud, addr, next)) {
-				entry = __pud(_pa(addr, mode));
+				entry = __pud(_pa(addr, _REGION3_SIZE, mode));
 				entry = set_pud_bit(entry, REGION3_KERNEL_EXEC);
 				set_pud(pud, entry);
 				continue;
@@ -202,6 +348,8 @@ static void pgtable_p4d_populate(pgd_t *pgd, unsigned long addr, unsigned long e
 	for (; addr < end; addr = next, p4d++) {
 		next = p4d_addr_end(addr, end);
 		if (p4d_none(*p4d)) {
+			if (kasan_p4d_populate_zero_shadow(p4d, addr, next, mode))
+				continue;
 			pud = boot_crst_alloc(_REGION3_ENTRY_EMPTY);
 			p4d_populate(&init_mm, p4d, pud);
 		}
@@ -219,9 +367,15 @@ static void pgtable_populate(unsigned long addr, unsigned long end, enum populat
 	for (; addr < end; addr = next, pgd++) {
 		next = pgd_addr_end(addr, end);
 		if (pgd_none(*pgd)) {
+			if (kasan_pgd_populate_zero_shadow(pgd, addr, next, mode))
+				continue;
 			p4d = boot_crst_alloc(_REGION2_ENTRY_EMPTY);
 			pgd_populate(&init_mm, pgd, p4d);
 		}
+#ifdef CONFIG_KASAN
+		if (mode == POPULATE_KASAN_SHALLOW)
+			continue;
+#endif
 		pgtable_p4d_populate(pgd, addr, next, mode);
 	}
 }
@@ -250,9 +404,8 @@ void setup_vmem(unsigned long asce_limit)
 	 * To prevent creation of a large page at address 0 first map
 	 * the lowcore and create the identity mapping only afterwards.
 	 */
-	pgtable_populate_init();
 	pgtable_populate(0, sizeof(struct lowcore), POPULATE_ONE2ONE);
-	for_each_mem_detect_usable_block(i, &start, &end)
+	for_each_physmem_usable_range(i, &start, &end)
 		pgtable_populate(start, end, POPULATE_ONE2ONE);
 	pgtable_populate(__abs_lowcore, __abs_lowcore + sizeof(struct lowcore),
 			 POPULATE_ABS_LOWCORE);
@@ -260,6 +413,8 @@ void setup_vmem(unsigned long asce_limit)
 			 POPULATE_NONE);
 	memcpy_real_ptep = __virt_to_kpte(__memcpy_real_area);
 
+	kasan_populate_shadow();
+
 	S390_lowcore.kernel_asce = swapper_pg_dir | asce_bits;
 	S390_lowcore.user_asce = s390_invalid_asce;
 
@@ -269,10 +424,3 @@ void setup_vmem(unsigned long asce_limit)
 
 	init_mm.context.asce = S390_lowcore.kernel_asce;
 }
-
-unsigned long vmem_estimate_memory_needs(unsigned long online_mem_total)
-{
-	unsigned long pages = DIV_ROUND_UP(online_mem_total, PAGE_SIZE);
-
-	return DIV_ROUND_UP(pages, _PAGE_ENTRIES) * _PAGE_TABLE_SIZE * 2;
-}
diff --git a/arch/s390/boot/vmlinux.lds.S b/arch/s390/boot/vmlinux.lds.S
index fa9d33b01b85..389df0e0d9e5 100644
--- a/arch/s390/boot/vmlinux.lds.S
+++ b/arch/s390/boot/vmlinux.lds.S
@@ -93,6 +93,8 @@ SECTIONS
 		_decompressor_syms_end = .;
 	}
 
+	_decompressor_end = .;
+
 #ifdef CONFIG_KERNEL_UNCOMPRESSED
 	. = 0x100000;
 #else
diff --git a/arch/s390/include/asm/kasan.h b/arch/s390/include/asm/kasan.h
index e5cfc81d5b61..0cffead0f2f2 100644
--- a/arch/s390/include/asm/kasan.h
+++ b/arch/s390/include/asm/kasan.h
@@ -2,7 +2,7 @@
 #ifndef __ASM_KASAN_H
 #define __ASM_KASAN_H
 
-#include <asm/pgtable.h>
+#include <linux/const.h>
 
 #ifdef CONFIG_KASAN
 
@@ -13,35 +13,6 @@
 #define KASAN_SHADOW_START	KASAN_SHADOW_OFFSET
 #define KASAN_SHADOW_END	(KASAN_SHADOW_START + KASAN_SHADOW_SIZE)
 
-extern void kasan_early_init(void);
-
-/*
- * Estimate kasan memory requirements, which it will reserve
- * at the very end of available physical memory. To estimate
- * that, we take into account that kasan would require
- * 1/8 of available physical memory (for shadow memory) +
- * creating page tables for the shadow memory region.
- * To keep page tables estimates simple take the double of
- * combined ptes size.
- *
- * physmem parameter has to be already adjusted if not entire physical memory
- * would be used (e.g. due to effect of "mem=" option).
- */
-static inline unsigned long kasan_estimate_memory_needs(unsigned long physmem)
-{
-	unsigned long kasan_needs;
-	unsigned long pages;
-	/* for shadow memory */
-	kasan_needs = round_up(physmem / 8, PAGE_SIZE);
-	/* for paging structures */
-	pages = DIV_ROUND_UP(kasan_needs, PAGE_SIZE);
-	kasan_needs += DIV_ROUND_UP(pages, _PAGE_ENTRIES) * _PAGE_TABLE_SIZE * 2;
-
-	return kasan_needs;
-}
-#else
-static inline void kasan_early_init(void) { }
-static inline unsigned long kasan_estimate_memory_needs(unsigned long physmem) { return 0; }
 #endif
 
 #endif
diff --git a/arch/s390/include/asm/mem_detect.h b/arch/s390/include/asm/mem_detect.h
deleted file mode 100644
index f9e7354036d2..000000000000
--- a/arch/s390/include/asm/mem_detect.h
+++ /dev/null
@@ -1,117 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef _ASM_S390_MEM_DETECT_H
-#define _ASM_S390_MEM_DETECT_H
-
-#include <linux/types.h>
-
-enum mem_info_source {
-	MEM_DETECT_NONE = 0,
-	MEM_DETECT_SCLP_STOR_INFO,
-	MEM_DETECT_DIAG260,
-	MEM_DETECT_SCLP_READ_INFO,
-	MEM_DETECT_BIN_SEARCH
-};
-
-struct mem_detect_block {
-	u64 start;
-	u64 end;
-};
-
-/*
- * Storage element id is defined as 1 byte (up to 256 storage elements).
- * In practise only storage element id 0 and 1 are used).
- * According to architecture one storage element could have as much as
- * 1020 subincrements. 255 mem_detect_blocks are embedded in mem_detect_info.
- * If more mem_detect_blocks are required, a block of memory from already
- * known mem_detect_block is taken (entries_extended points to it).
- */
-#define MEM_INLINED_ENTRIES 255 /* (PAGE_SIZE - 16) / 16 */
-
-struct mem_detect_info {
-	u32 count;
-	u8 info_source;
-	unsigned long usable;
-	struct mem_detect_block entries[MEM_INLINED_ENTRIES];
-	struct mem_detect_block *entries_extended;
-};
-extern struct mem_detect_info mem_detect;
-
-void add_mem_detect_block(u64 start, u64 end);
-
-static inline int __get_mem_detect_block(u32 n, unsigned long *start,
-					 unsigned long *end, bool respect_usable_limit)
-{
-	if (n >= mem_detect.count) {
-		*start = 0;
-		*end = 0;
-		return -1;
-	}
-
-	if (n < MEM_INLINED_ENTRIES) {
-		*start = (unsigned long)mem_detect.entries[n].start;
-		*end = (unsigned long)mem_detect.entries[n].end;
-	} else {
-		*start = (unsigned long)mem_detect.entries_extended[n - MEM_INLINED_ENTRIES].start;
-		*end = (unsigned long)mem_detect.entries_extended[n - MEM_INLINED_ENTRIES].end;
-	}
-
-	if (respect_usable_limit && mem_detect.usable) {
-		if (*start >= mem_detect.usable)
-			return -1;
-		if (*end > mem_detect.usable)
-			*end = mem_detect.usable;
-	}
-	return 0;
-}
-
-/**
- * for_each_mem_detect_usable_block - early online memory range iterator
- * @i: an integer used as loop variable
- * @p_start: ptr to unsigned long for start address of the range
- * @p_end: ptr to unsigned long for end address of the range
- *
- * Walks over detected online memory ranges below usable limit.
- */
-#define for_each_mem_detect_usable_block(i, p_start, p_end)		\
-	for (i = 0; !__get_mem_detect_block(i, p_start, p_end, true); i++)
-
-/* Walks over all detected online memory ranges disregarding usable limit. */
-#define for_each_mem_detect_block(i, p_start, p_end)		\
-	for (i = 0; !__get_mem_detect_block(i, p_start, p_end, false); i++)
-
-static inline unsigned long get_mem_detect_usable_total(void)
-{
-	unsigned long start, end, total = 0;
-	int i;
-
-	for_each_mem_detect_usable_block(i, &start, &end)
-		total += end - start;
-
-	return total;
-}
-
-static inline void get_mem_detect_reserved(unsigned long *start,
-					   unsigned long *size)
-{
-	*start = (unsigned long)mem_detect.entries_extended;
-	if (mem_detect.count > MEM_INLINED_ENTRIES)
-		*size = (mem_detect.count - MEM_INLINED_ENTRIES) * sizeof(struct mem_detect_block);
-	else
-		*size = 0;
-}
-
-static inline unsigned long get_mem_detect_end(void)
-{
-	unsigned long start;
-	unsigned long end;
-
-	if (mem_detect.usable)
-		return mem_detect.usable;
-	if (mem_detect.count) {
-		__get_mem_detect_block(mem_detect.count - 1, &start, &end, false);
-		return end;
-	}
-	return 0;
-}
-
-#endif
diff --git a/arch/s390/include/asm/physmem_info.h b/arch/s390/include/asm/physmem_info.h
new file mode 100644
index 000000000000..8e9c582592b3
--- /dev/null
+++ b/arch/s390/include/asm/physmem_info.h
@@ -0,0 +1,171 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_S390_MEM_DETECT_H
+#define _ASM_S390_MEM_DETECT_H
+
+#include <linux/types.h>
+
+enum physmem_info_source {
+	MEM_DETECT_NONE = 0,
+	MEM_DETECT_SCLP_STOR_INFO,
+	MEM_DETECT_DIAG260,
+	MEM_DETECT_SCLP_READ_INFO,
+	MEM_DETECT_BIN_SEARCH
+};
+
+struct physmem_range {
+	u64 start;
+	u64 end;
+};
+
+enum reserved_range_type {
+	RR_DECOMPRESSOR,
+	RR_INITRD,
+	RR_VMLINUX,
+	RR_AMODE31,
+	RR_IPLREPORT,
+	RR_CERT_COMP_LIST,
+	RR_MEM_DETECT_EXTENDED,
+	RR_VMEM,
+	RR_MAX
+};
+
+struct reserved_range {
+	unsigned long start;
+	unsigned long end;
+	struct reserved_range *chain;
+};
+
+/*
+ * Storage element id is defined as 1 byte (up to 256 storage elements).
+ * In practise only storage element id 0 and 1 are used).
+ * According to architecture one storage element could have as much as
+ * 1020 subincrements. 255 physmem_ranges are embedded in physmem_info.
+ * If more physmem_ranges are required, a block of memory from already
+ * known physmem_range is taken (online_extended points to it).
+ */
+#define MEM_INLINED_ENTRIES 255 /* (PAGE_SIZE - 16) / 16 */
+
+struct physmem_info {
+	u32 range_count;
+	u8 info_source;
+	unsigned long usable;
+	struct reserved_range reserved[RR_MAX];
+	struct physmem_range online[MEM_INLINED_ENTRIES];
+	struct physmem_range *online_extended;
+};
+
+extern struct physmem_info physmem_info;
+
+void add_physmem_online_range(u64 start, u64 end);
+
+static inline int __get_physmem_range(u32 n, unsigned long *start,
+				      unsigned long *end, bool respect_usable_limit)
+{
+	if (n >= physmem_info.range_count) {
+		*start = 0;
+		*end = 0;
+		return -1;
+	}
+
+	if (n < MEM_INLINED_ENTRIES) {
+		*start = (unsigned long)physmem_info.online[n].start;
+		*end = (unsigned long)physmem_info.online[n].end;
+	} else {
+		*start = (unsigned long)physmem_info.online_extended[n - MEM_INLINED_ENTRIES].start;
+		*end = (unsigned long)physmem_info.online_extended[n - MEM_INLINED_ENTRIES].end;
+	}
+
+	if (respect_usable_limit && physmem_info.usable) {
+		if (*start >= physmem_info.usable)
+			return -1;
+		if (*end > physmem_info.usable)
+			*end = physmem_info.usable;
+	}
+	return 0;
+}
+
+/**
+ * for_each_physmem_usable_range - early online memory range iterator
+ * @i: an integer used as loop variable
+ * @p_start: ptr to unsigned long for start address of the range
+ * @p_end: ptr to unsigned long for end address of the range
+ *
+ * Walks over detected online memory ranges below usable limit.
+ */
+#define for_each_physmem_usable_range(i, p_start, p_end)		\
+	for (i = 0; !__get_physmem_range(i, p_start, p_end, true); i++)
+
+/* Walks over all detected online memory ranges disregarding usable limit. */
+#define for_each_physmem_online_range(i, p_start, p_end)		\
+	for (i = 0; !__get_physmem_range(i, p_start, p_end, false); i++)
+
+static inline const char *get_physmem_info_source(void)
+{
+	switch (physmem_info.info_source) {
+	case MEM_DETECT_SCLP_STOR_INFO:
+		return "sclp storage info";
+	case MEM_DETECT_DIAG260:
+		return "diag260";
+	case MEM_DETECT_SCLP_READ_INFO:
+		return "sclp read info";
+	case MEM_DETECT_BIN_SEARCH:
+		return "binary search";
+	}
+	return "none";
+}
+
+#define RR_TYPE_NAME(t) case RR_ ## t: return #t
+static inline const char *get_rr_type_name(enum reserved_range_type t)
+{
+	switch (t) {
+	RR_TYPE_NAME(DECOMPRESSOR);
+	RR_TYPE_NAME(INITRD);
+	RR_TYPE_NAME(VMLINUX);
+	RR_TYPE_NAME(AMODE31);
+	RR_TYPE_NAME(IPLREPORT);
+	RR_TYPE_NAME(CERT_COMP_LIST);
+	RR_TYPE_NAME(MEM_DETECT_EXTENDED);
+	RR_TYPE_NAME(VMEM);
+	default:
+		return "UNKNOWN";
+	}
+}
+
+#define for_each_physmem_reserved_type_range(t, range, p_start, p_end)				\
+	for (range = &physmem_info.reserved[t], *p_start = range->start, *p_end = range->end;	\
+	     range && range->end; range = range->chain,						\
+	     *p_start = range ? range->start : 0, *p_end = range ? range->end : 0)
+
+static inline struct reserved_range *__physmem_reserved_next(enum reserved_range_type *t,
+							     struct reserved_range *range)
+{
+	if (!range) {
+		range = &physmem_info.reserved[*t];
+		if (range->end)
+			return range;
+	}
+	if (range->chain)
+		return range->chain;
+	while (++*t < RR_MAX) {
+		range = &physmem_info.reserved[*t];
+		if (range->end)
+			return range;
+	}
+	return NULL;
+}
+
+#define for_each_physmem_reserved_range(t, range, p_start, p_end)			\
+	for (t = 0, range = __physmem_reserved_next(&t, NULL),			\
+	    *p_start = range ? range->start : 0, *p_end = range ? range->end : 0;	\
+	     range; range = __physmem_reserved_next(&t, range),			\
+	    *p_start = range ? range->start : 0, *p_end = range ? range->end : 0)
+
+static inline unsigned long get_physmem_reserved(enum reserved_range_type type,
+						 unsigned long *addr, unsigned long *size)
+{
+	*addr = physmem_info.reserved[type].start;
+	*size = physmem_info.reserved[type].end - physmem_info.reserved[type].start;
+	return *size;
+}
+
+#endif
diff --git a/arch/s390/include/asm/setup.h b/arch/s390/include/asm/setup.h
index 5271bb278cfa..b28d250efbaa 100644
--- a/arch/s390/include/asm/setup.h
+++ b/arch/s390/include/asm/setup.h
@@ -74,10 +74,6 @@ extern unsigned int zlib_dfltcc_support;
 
 extern int noexec_disabled;
 extern unsigned long ident_map_size;
-extern unsigned long pgalloc_pos;
-extern unsigned long pgalloc_end;
-extern unsigned long pgalloc_low;
-extern unsigned long __amode31_base;
 
 /* The Write Back bit position in the physaddr is given by the SLPC PCI */
 extern unsigned long mio_wb_bit_mask;
@@ -150,13 +146,6 @@ static inline unsigned long kaslr_offset(void)
 	return __kaslr_offset;
 }
 
-extern int is_full_image;
-
-struct initrd_data {
-	unsigned long start;
-	unsigned long size;
-};
-extern struct initrd_data initrd_data;
 
 struct oldmem_data {
 	unsigned long start;
diff --git a/arch/s390/kernel/early.c b/arch/s390/kernel/early.c
index d26f02495636..2dd5976a55ac 100644
--- a/arch/s390/kernel/early.c
+++ b/arch/s390/kernel/early.c
@@ -34,8 +34,6 @@
 #include <asm/switch_to.h>
 #include "entry.h"
 
-int __bootdata(is_full_image);
-
 #define decompressor_handled_param(param)			\
 static int __init ignore_decompressor_param_##param(char *s)	\
 {								\
@@ -53,6 +51,14 @@ decompressor_handled_param(nokaslr);
 decompressor_handled_param(prot_virt);
 #endif
 
+static void __init kasan_early_init(void)
+{
+#ifdef CONFIG_KASAN
+	init_task.kasan_depth = 0;
+	sclp_early_printk("KernelAddressSanitizer initialized\n");
+#endif
+}
+
 static void __init reset_tod_clock(void)
 {
 	union tod_clock clk;
@@ -288,17 +294,6 @@ static void __init setup_boot_command_line(void)
 	strscpy(boot_command_line, early_command_line, COMMAND_LINE_SIZE);
 }
 
-static void __init check_image_bootable(void)
-{
-	if (is_full_image)
-		return;
-
-	sclp_early_printk("Linux kernel boot failure: An attempt to boot a vmlinux ELF image failed.\n");
-	sclp_early_printk("This image does not contain all parts necessary for starting up. Use\n");
-	sclp_early_printk("bzImage or arch/s390/boot/compressed/vmlinux instead.\n");
-	disabled_wait();
-}
-
 static void __init sort_amode31_extable(void)
 {
 	sort_extable(__start_amode31_ex_table, __stop_amode31_ex_table);
@@ -306,8 +301,8 @@ static void __init sort_amode31_extable(void)
 
 void __init startup_init(void)
 {
+	kasan_early_init();
 	reset_tod_clock();
-	check_image_bootable();
 	time_early_init();
 	init_kernel_storage_key();
 	lockdep_off();
diff --git a/arch/s390/kernel/head64.S b/arch/s390/kernel/head64.S
index 3b3bf8329e6c..f68be3951103 100644
--- a/arch/s390/kernel/head64.S
+++ b/arch/s390/kernel/head64.S
@@ -26,9 +26,6 @@ ENTRY(startup_continue)
 	stg	%r14,__LC_CURRENT
 	larl	%r15,init_thread_union+THREAD_SIZE-STACK_FRAME_OVERHEAD-__PT_SIZE
 	brasl	%r14,sclp_early_adjust_va	# allow sclp_early_printk
-#ifdef CONFIG_KASAN
-	brasl	%r14,kasan_early_init
-#endif
 	brasl	%r14,startup_init		# s390 specific early init
 	brasl	%r14,start_kernel		# common init code
 #
diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c
index 8ec5cdf9dadc..d25425b8d0c0 100644
--- a/arch/s390/kernel/setup.c
+++ b/arch/s390/kernel/setup.c
@@ -74,7 +74,7 @@
 #include <asm/numa.h>
 #include <asm/alternative.h>
 #include <asm/nospec-branch.h>
-#include <asm/mem_detect.h>
+#include <asm/physmem_info.h>
 #include <asm/maccess.h>
 #include <asm/uv.h>
 #include <asm/asm-offsets.h>
@@ -147,14 +147,9 @@ static u32 __amode31_ref *__ctl_duct = __ctl_duct_amode31;
 
 int __bootdata(noexec_disabled);
 unsigned long __bootdata(ident_map_size);
-struct mem_detect_info __bootdata(mem_detect);
-struct initrd_data __bootdata(initrd_data);
-unsigned long __bootdata(pgalloc_pos);
-unsigned long __bootdata(pgalloc_end);
-unsigned long __bootdata(pgalloc_low);
+struct physmem_info __bootdata(physmem_info);
 
 unsigned long __bootdata_preserved(__kaslr_offset);
-unsigned long __bootdata(__amode31_base);
 unsigned int __bootdata_preserved(zlib_dfltcc_support);
 EXPORT_SYMBOL(zlib_dfltcc_support);
 u64 __bootdata_preserved(stfle_fac_list[16]);
@@ -635,7 +630,11 @@ static struct notifier_block kdump_mem_nb = {
  */
 static void __init reserve_pgtables(void)
 {
-	memblock_reserve(pgalloc_pos, pgalloc_end - pgalloc_pos);
+	unsigned long start, end;
+	struct reserved_range *range;
+
+	for_each_physmem_reserved_type_range(RR_VMEM, range, &start, &end)
+		memblock_reserve(start, end - start);
 }
 
 /*
@@ -712,13 +711,13 @@ static void __init reserve_crashkernel(void)
  */
 static void __init reserve_initrd(void)
 {
-#ifdef CONFIG_BLK_DEV_INITRD
-	if (!initrd_data.start || !initrd_data.size)
+	unsigned long addr, size;
+
+	if (!IS_ENABLED(CONFIG_BLK_DEV_INITRD) || !get_physmem_reserved(RR_INITRD, &addr, &size))
 		return;
-	initrd_start = (unsigned long)__va(initrd_data.start);
-	initrd_end = initrd_start + initrd_data.size;
-	memblock_reserve(initrd_data.start, initrd_data.size);
-#endif
+	initrd_start = (unsigned long)__va(addr);
+	initrd_end = initrd_start + size;
+	memblock_reserve(addr, size);
 }
 
 /*
@@ -730,72 +729,40 @@ static void __init reserve_certificate_list(void)
 		memblock_reserve(ipl_cert_list_addr, ipl_cert_list_size);
 }
 
-static void __init reserve_mem_detect_info(void)
+static void __init reserve_physmem_info(void)
 {
-	unsigned long start, size;
+	unsigned long addr, size;
 
-	get_mem_detect_reserved(&start, &size);
-	if (size)
-		memblock_reserve(start, size);
+	if (get_physmem_reserved(RR_MEM_DETECT_EXTENDED, &addr, &size))
+		memblock_reserve(addr, size);
 }
 
-static void __init free_mem_detect_info(void)
+static void __init free_physmem_info(void)
 {
-	unsigned long start, size;
+	unsigned long addr, size;
 
-	get_mem_detect_reserved(&start, &size);
-	if (size)
-		memblock_phys_free(start, size);
-}
-
-static const char * __init get_mem_info_source(void)
-{
-	switch (mem_detect.info_source) {
-	case MEM_DETECT_SCLP_STOR_INFO:
-		return "sclp storage info";
-	case MEM_DETECT_DIAG260:
-		return "diag260";
-	case MEM_DETECT_SCLP_READ_INFO:
-		return "sclp read info";
-	case MEM_DETECT_BIN_SEARCH:
-		return "binary search";
-	}
-	return "none";
+	if (get_physmem_reserved(RR_MEM_DETECT_EXTENDED, &addr, &size))
+		memblock_phys_free(addr, size);
 }
 
-static void __init memblock_add_mem_detect_info(void)
+static void __init memblock_add_physmem_info(void)
 {
 	unsigned long start, end;
 	int i;
 
 	pr_debug("physmem info source: %s (%hhd)\n",
-		 get_mem_info_source(), mem_detect.info_source);
+		 get_physmem_info_source(), physmem_info.info_source);
 	/* keep memblock lists close to the kernel */
 	memblock_set_bottom_up(true);
-	for_each_mem_detect_usable_block(i, &start, &end)
+	for_each_physmem_usable_range(i, &start, &end)
 		memblock_add(start, end - start);
-	for_each_mem_detect_block(i, &start, &end)
+	for_each_physmem_online_range(i, &start, &end)
 		memblock_physmem_add(start, end - start);
 	memblock_set_bottom_up(false);
 	memblock_set_node(0, ULONG_MAX, &memblock.memory, 0);
 }
 
 /*
- * Check for initrd being in usable memory
- */
-static void __init check_initrd(void)
-{
-#ifdef CONFIG_BLK_DEV_INITRD
-	if (initrd_data.start && initrd_data.size &&
-	    !memblock_is_region_memory(initrd_data.start, initrd_data.size)) {
-		pr_err("The initial RAM disk does not fit into the memory\n");
-		memblock_phys_free(initrd_data.start, initrd_data.size);
-		initrd_start = initrd_end = 0;
-	}
-#endif
-}
-
-/*
  * Reserve memory used for lowcore/command line/kernel image.
  */
 static void __init reserve_kernel(void)
@@ -803,7 +770,7 @@ static void __init reserve_kernel(void)
 	memblock_reserve(0, STARTUP_NORMAL_OFFSET);
 	memblock_reserve(OLDMEM_BASE, sizeof(unsigned long));
 	memblock_reserve(OLDMEM_SIZE, sizeof(unsigned long));
-	memblock_reserve(__amode31_base, __eamode31 - __samode31);
+	memblock_reserve(physmem_info.reserved[RR_AMODE31].start, __eamode31 - __samode31);
 	memblock_reserve(__pa(sclp_early_sccb), EXT_SCCB_READ_SCP);
 	memblock_reserve(__pa(_stext), _end - _stext);
 }
@@ -825,13 +792,13 @@ static void __init setup_memory(void)
 static void __init relocate_amode31_section(void)
 {
 	unsigned long amode31_size = __eamode31 - __samode31;
-	long amode31_offset = __amode31_base - __samode31;
+	long amode31_offset = physmem_info.reserved[RR_AMODE31].start - __samode31;
 	long *ptr;
 
 	pr_info("Relocating AMODE31 section of size 0x%08lx\n", amode31_size);
 
 	/* Move original AMODE31 section to the new one */
-	memmove((void *)__amode31_base, (void *)__samode31, amode31_size);
+	memmove((void *)physmem_info.reserved[RR_AMODE31].start, (void *)__samode31, amode31_size);
 	/* Zero out the old AMODE31 section to catch invalid accesses within it */
 	memset((void *)__samode31, 0, amode31_size);
 
@@ -997,14 +964,14 @@ void __init setup_arch(char **cmdline_p)
 	reserve_kernel();
 	reserve_initrd();
 	reserve_certificate_list();
-	reserve_mem_detect_info();
+	reserve_physmem_info();
 	memblock_set_current_limit(ident_map_size);
 	memblock_allow_resize();
 
 	/* Get information about *all* installed memory */
-	memblock_add_mem_detect_info();
+	memblock_add_physmem_info();
 
-	free_mem_detect_info();
+	free_physmem_info();
 	setup_memory_end();
 	memblock_dump_all();
 	setup_memory();
@@ -1017,7 +984,6 @@ void __init setup_arch(char **cmdline_p)
 	if (MACHINE_HAS_EDAT2)
 		hugetlb_cma_reserve(PUD_SHIFT - PAGE_SHIFT);
 
-	check_initrd();
 	reserve_crashkernel();
 #ifdef CONFIG_CRASH_DUMP
 	/*
diff --git a/arch/s390/kernel/vmlinux.lds.S b/arch/s390/kernel/vmlinux.lds.S
index b653ba8d51e6..8d2288a5ba25 100644
--- a/arch/s390/kernel/vmlinux.lds.S
+++ b/arch/s390/kernel/vmlinux.lds.S
@@ -219,6 +219,13 @@ SECTIONS
 		QUAD(init_mm)
 		QUAD(swapper_pg_dir)
 		QUAD(invalid_pg_dir)
+#ifdef CONFIG_KASAN
+		QUAD(kasan_early_shadow_page)
+		QUAD(kasan_early_shadow_pte)
+		QUAD(kasan_early_shadow_pmd)
+		QUAD(kasan_early_shadow_pud)
+		QUAD(kasan_early_shadow_p4d)
+#endif
 	} :NONE
 
 	/* Debugging sections.	*/
diff --git a/arch/s390/mm/Makefile b/arch/s390/mm/Makefile
index 57e4f3a24829..d90db06a8af5 100644
--- a/arch/s390/mm/Makefile
+++ b/arch/s390/mm/Makefile
@@ -10,6 +10,3 @@ obj-$(CONFIG_CMM)		+= cmm.o
 obj-$(CONFIG_HUGETLB_PAGE)	+= hugetlbpage.o
 obj-$(CONFIG_PTDUMP_CORE)	+= dump_pagetables.o
 obj-$(CONFIG_PGSTE)		+= gmap.o
-
-KASAN_SANITIZE_kasan_init.o	:= n
-obj-$(CONFIG_KASAN)		+= kasan_init.o
diff --git a/arch/s390/mm/kasan_init.c b/arch/s390/mm/kasan_init.c
deleted file mode 100644
index ef89a5f26853..000000000000
--- a/arch/s390/mm/kasan_init.c
+++ /dev/null
@@ -1,301 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-#include <linux/kasan.h>
-#include <linux/sched/task.h>
-#include <linux/pgtable.h>
-#include <asm/pgalloc.h>
-#include <asm/kasan.h>
-#include <asm/mem_detect.h>
-#include <asm/processor.h>
-#include <asm/sclp.h>
-#include <asm/facility.h>
-#include <asm/sections.h>
-#include <asm/setup.h>
-#include <asm/uv.h>
-
-static unsigned long segment_pos __initdata;
-static unsigned long segment_low __initdata;
-static bool has_edat __initdata;
-static bool has_nx __initdata;
-
-#define __sha(x) ((unsigned long)kasan_mem_to_shadow((void *)x))
-
-static void __init kasan_early_panic(const char *reason)
-{
-	sclp_early_printk("The Linux kernel failed to boot with the KernelAddressSanitizer:\n");
-	sclp_early_printk(reason);
-	disabled_wait();
-}
-
-static void * __init kasan_early_alloc_segment(void)
-{
-	segment_pos -= _SEGMENT_SIZE;
-
-	if (segment_pos < segment_low)
-		kasan_early_panic("out of memory during initialisation\n");
-
-	return __va(segment_pos);
-}
-
-static void * __init kasan_early_alloc_pages(unsigned int order)
-{
-	pgalloc_pos -= (PAGE_SIZE << order);
-
-	if (pgalloc_pos < pgalloc_low)
-		kasan_early_panic("out of memory during initialisation\n");
-
-	return __va(pgalloc_pos);
-}
-
-static void * __init kasan_early_crst_alloc(unsigned long val)
-{
-	unsigned long *table;
-
-	table = kasan_early_alloc_pages(CRST_ALLOC_ORDER);
-	if (table)
-		crst_table_init(table, val);
-	return table;
-}
-
-static pte_t * __init kasan_early_pte_alloc(void)
-{
-	static void *pte_leftover;
-	pte_t *pte;
-
-	BUILD_BUG_ON(_PAGE_TABLE_SIZE * 2 != PAGE_SIZE);
-
-	if (!pte_leftover) {
-		pte_leftover = kasan_early_alloc_pages(0);
-		pte = pte_leftover + _PAGE_TABLE_SIZE;
-	} else {
-		pte = pte_leftover;
-		pte_leftover = NULL;
-	}
-	memset64((u64 *)pte, _PAGE_INVALID, PTRS_PER_PTE);
-	return pte;
-}
-
-enum populate_mode {
-	POPULATE_MAP,
-	POPULATE_ZERO_SHADOW,
-	POPULATE_SHALLOW
-};
-
-static inline pgprot_t pgprot_clear_bit(pgprot_t pgprot, unsigned long bit)
-{
-	return __pgprot(pgprot_val(pgprot) & ~bit);
-}
-
-static void __init kasan_early_pgtable_populate(unsigned long address,
-						unsigned long end,
-						enum populate_mode mode)
-{
-	pgprot_t pgt_prot_zero = PAGE_KERNEL_RO;
-	pgprot_t pgt_prot = PAGE_KERNEL;
-	pgprot_t sgt_prot = SEGMENT_KERNEL;
-	pgd_t *pg_dir;
-	p4d_t *p4_dir;
-	pud_t *pu_dir;
-	pmd_t *pm_dir;
-	pte_t *pt_dir;
-	pmd_t pmd;
-	pte_t pte;
-
-	if (!has_nx) {
-		pgt_prot_zero = pgprot_clear_bit(pgt_prot_zero, _PAGE_NOEXEC);
-		pgt_prot = pgprot_clear_bit(pgt_prot, _PAGE_NOEXEC);
-		sgt_prot = pgprot_clear_bit(sgt_prot, _SEGMENT_ENTRY_NOEXEC);
-	}
-
-	while (address < end) {
-		pg_dir = pgd_offset_k(address);
-		if (pgd_none(*pg_dir)) {
-			if (mode == POPULATE_ZERO_SHADOW &&
-			    IS_ALIGNED(address, PGDIR_SIZE) &&
-			    end - address >= PGDIR_SIZE) {
-				pgd_populate(&init_mm, pg_dir,
-						kasan_early_shadow_p4d);
-				address = (address + PGDIR_SIZE) & PGDIR_MASK;
-				continue;
-			}
-			p4_dir = kasan_early_crst_alloc(_REGION2_ENTRY_EMPTY);
-			pgd_populate(&init_mm, pg_dir, p4_dir);
-		}
-
-		if (mode == POPULATE_SHALLOW) {
-			address = (address + P4D_SIZE) & P4D_MASK;
-			continue;
-		}
-
-		p4_dir = p4d_offset(pg_dir, address);
-		if (p4d_none(*p4_dir)) {
-			if (mode == POPULATE_ZERO_SHADOW &&
-			    IS_ALIGNED(address, P4D_SIZE) &&
-			    end - address >= P4D_SIZE) {
-				p4d_populate(&init_mm, p4_dir,
-						kasan_early_shadow_pud);
-				address = (address + P4D_SIZE) & P4D_MASK;
-				continue;
-			}
-			pu_dir = kasan_early_crst_alloc(_REGION3_ENTRY_EMPTY);
-			p4d_populate(&init_mm, p4_dir, pu_dir);
-		}
-
-		pu_dir = pud_offset(p4_dir, address);
-		if (pud_none(*pu_dir)) {
-			if (mode == POPULATE_ZERO_SHADOW &&
-			    IS_ALIGNED(address, PUD_SIZE) &&
-			    end - address >= PUD_SIZE) {
-				pud_populate(&init_mm, pu_dir,
-						kasan_early_shadow_pmd);
-				address = (address + PUD_SIZE) & PUD_MASK;
-				continue;
-			}
-			pm_dir = kasan_early_crst_alloc(_SEGMENT_ENTRY_EMPTY);
-			pud_populate(&init_mm, pu_dir, pm_dir);
-		}
-
-		pm_dir = pmd_offset(pu_dir, address);
-		if (pmd_none(*pm_dir)) {
-			if (IS_ALIGNED(address, PMD_SIZE) &&
-			    end - address >= PMD_SIZE) {
-				if (mode == POPULATE_ZERO_SHADOW) {
-					pmd_populate(&init_mm, pm_dir, kasan_early_shadow_pte);
-					address = (address + PMD_SIZE) & PMD_MASK;
-					continue;
-				} else if (has_edat) {
-					void *page = kasan_early_alloc_segment();
-
-					memset(page, 0, _SEGMENT_SIZE);
-					pmd = __pmd(__pa(page));
-					pmd = set_pmd_bit(pmd, sgt_prot);
-					set_pmd(pm_dir, pmd);
-					address = (address + PMD_SIZE) & PMD_MASK;
-					continue;
-				}
-			}
-			pt_dir = kasan_early_pte_alloc();
-			pmd_populate(&init_mm, pm_dir, pt_dir);
-		} else if (pmd_large(*pm_dir)) {
-			address = (address + PMD_SIZE) & PMD_MASK;
-			continue;
-		}
-
-		pt_dir = pte_offset_kernel(pm_dir, address);
-		if (pte_none(*pt_dir)) {
-			void *page;
-
-			switch (mode) {
-			case POPULATE_MAP:
-				page = kasan_early_alloc_pages(0);
-				memset(page, 0, PAGE_SIZE);
-				pte = __pte(__pa(page));
-				pte = set_pte_bit(pte, pgt_prot);
-				set_pte(pt_dir, pte);
-				break;
-			case POPULATE_ZERO_SHADOW:
-				page = kasan_early_shadow_page;
-				pte = __pte(__pa(page));
-				pte = set_pte_bit(pte, pgt_prot_zero);
-				set_pte(pt_dir, pte);
-				break;
-			case POPULATE_SHALLOW:
-				/* should never happen */
-				break;
-			}
-		}
-		address += PAGE_SIZE;
-	}
-}
-
-static void __init kasan_early_detect_facilities(void)
-{
-	if (test_facility(8)) {
-		has_edat = true;
-		__ctl_set_bit(0, 23);
-	}
-	if (!noexec_disabled && test_facility(130)) {
-		has_nx = true;
-		__ctl_set_bit(0, 20);
-	}
-}
-
-void __init kasan_early_init(void)
-{
-	pte_t pte_z = __pte(__pa(kasan_early_shadow_page) | pgprot_val(PAGE_KERNEL_RO));
-	pmd_t pmd_z = __pmd(__pa(kasan_early_shadow_pte) | _SEGMENT_ENTRY);
-	pud_t pud_z = __pud(__pa(kasan_early_shadow_pmd) | _REGION3_ENTRY);
-	p4d_t p4d_z = __p4d(__pa(kasan_early_shadow_pud) | _REGION2_ENTRY);
-	unsigned long untracked_end = MODULES_VADDR;
-	unsigned long shadow_alloc_size;
-	unsigned long start, end;
-	int i;
-
-	kasan_early_detect_facilities();
-	if (!has_nx)
-		pte_z = clear_pte_bit(pte_z, __pgprot(_PAGE_NOEXEC));
-
-	BUILD_BUG_ON(!IS_ALIGNED(KASAN_SHADOW_START, P4D_SIZE));
-	BUILD_BUG_ON(!IS_ALIGNED(KASAN_SHADOW_END, P4D_SIZE));
-
-	/* init kasan zero shadow */
-	crst_table_init((unsigned long *)kasan_early_shadow_p4d, p4d_val(p4d_z));
-	crst_table_init((unsigned long *)kasan_early_shadow_pud, pud_val(pud_z));
-	crst_table_init((unsigned long *)kasan_early_shadow_pmd, pmd_val(pmd_z));
-	memset64((u64 *)kasan_early_shadow_pte, pte_val(pte_z), PTRS_PER_PTE);
-
-	if (has_edat) {
-		shadow_alloc_size = get_mem_detect_usable_total() >> KASAN_SHADOW_SCALE_SHIFT;
-		segment_pos = round_down(pgalloc_pos, _SEGMENT_SIZE);
-		segment_low = segment_pos - shadow_alloc_size;
-		segment_low = round_down(segment_low, _SEGMENT_SIZE);
-		pgalloc_pos = segment_low;
-	}
-	/*
-	 * Current memory layout:
-	 * +- 0 -------------+	       +- shadow start -+
-	 * |1:1 ident mapping|	      /|1/8 of ident map|
-	 * |		     |	     / |		|
-	 * +-end of ident map+	    /  +----------------+
-	 * | ... gap ...     |	   /   |    kasan	|
-	 * |		     |	  /    |  zero page	|
-	 * +- vmalloc area  -+	 /     |   mapping	|
-	 * | vmalloc_size    |	/      | (untracked)	|
-	 * +- modules vaddr -+ /       +----------------+
-	 * | 2Gb	     |/        |    unmapped	| allocated per module
-	 * +- shadow start  -+	       +----------------+
-	 * | 1/8 addr space  |	       | zero pg mapping| (untracked)
-	 * +- shadow end ----+---------+- shadow end ---+
-	 *
-	 * Current memory layout (KASAN_VMALLOC):
-	 * +- 0 -------------+	       +- shadow start -+
-	 * |1:1 ident mapping|	      /|1/8 of ident map|
-	 * |		     |	     / |		|
-	 * +-end of ident map+	    /  +----------------+
-	 * | ... gap ...     |	   /   | kasan zero page| (untracked)
-	 * |		     |	  /    | mapping	|
-	 * +- vmalloc area  -+	 /     +----------------+
-	 * | vmalloc_size    |	/      |shallow populate|
-	 * +- modules vaddr -+ /       +----------------+
-	 * | 2Gb	     |/        |shallow populate|
-	 * +- shadow start  -+	       +----------------+
-	 * | 1/8 addr space  |	       | zero pg mapping| (untracked)
-	 * +- shadow end ----+---------+- shadow end ---+
-	 */
-	/* populate kasan shadow (for identity mapping and zero page mapping) */
-	for_each_mem_detect_usable_block(i, &start, &end)
-		kasan_early_pgtable_populate(__sha(start), __sha(end), POPULATE_MAP);
-	if (IS_ENABLED(CONFIG_KASAN_VMALLOC)) {
-		untracked_end = VMALLOC_START;
-		/* shallowly populate kasan shadow for vmalloc and modules */
-		kasan_early_pgtable_populate(__sha(VMALLOC_START), __sha(MODULES_END),
-					     POPULATE_SHALLOW);
-	}
-	/* populate kasan shadow for untracked memory */
-	kasan_early_pgtable_populate(__sha(ident_map_size), __sha(untracked_end),
-				     POPULATE_ZERO_SHADOW);
-	kasan_early_pgtable_populate(__sha(MODULES_END), __sha(_REGION1_SIZE),
-				     POPULATE_ZERO_SHADOW);
-	/* enable kasan */
-	init_task.kasan_depth = 0;
-	sclp_early_printk("KernelAddressSanitizer initialized\n");
-}
diff --git a/arch/s390/mm/pageattr.c b/arch/s390/mm/pageattr.c
index 85195c18b2e8..7838e9c70000 100644
--- a/arch/s390/mm/pageattr.c
+++ b/arch/s390/mm/pageattr.c
@@ -300,8 +300,6 @@ static int change_page_attr(unsigned long addr, unsigned long end,
 
 	if (addr == end)
 		return 0;
-	if (end >= MODULES_END)
-		return -EINVAL;
 	mutex_lock(&cpa_mutex);
 	pgdp = pgd_offset_k(addr);
 	do {
diff --git a/arch/s390/mm/vmem.c b/arch/s390/mm/vmem.c
index 4113a7ffa149..242f95aa9801 100644
--- a/arch/s390/mm/vmem.c
+++ b/arch/s390/mm/vmem.c
@@ -5,6 +5,7 @@
 
 #include <linux/memory_hotplug.h>
 #include <linux/memblock.h>
+#include <linux/kasan.h>
 #include <linux/pfn.h>
 #include <linux/mm.h>
 #include <linux/init.h>
@@ -664,6 +665,9 @@ static void __init memblock_region_swap(void *a, void *b, int size)
 	swap(*(struct memblock_region *)a, *(struct memblock_region *)b);
 }
 
+#ifdef CONFIG_KASAN
+#define __sha(x)	((unsigned long)kasan_mem_to_shadow((void *)x))
+#endif
 /*
  * map whole physical memory to virtual memory (identity mapping)
  * we reserve enough space in the vmalloc area for vmemmap to hotplug
@@ -733,6 +737,13 @@ void __init vmem_map_init(void)
 			     SET_MEMORY_RW | SET_MEMORY_NX);
 	}
 
+#ifdef CONFIG_KASAN
+	for_each_mem_range(i, &base, &end)
+		__set_memory(__sha(base),
+			     (__sha(end) - __sha(base)) >> PAGE_SHIFT,
+			     SET_MEMORY_RW | SET_MEMORY_NX);
+#endif
+
 	__set_memory((unsigned long)_stext,
 		     (unsigned long)(_etext - _stext) >> PAGE_SHIFT,
 		     SET_MEMORY_RO | SET_MEMORY_X);
diff --git a/drivers/s390/char/sclp_early_core.c b/drivers/s390/char/sclp_early_core.c
index ac1d00980fa6..dbd5c53d8edf 100644
--- a/drivers/s390/char/sclp_early_core.c
+++ b/drivers/s390/char/sclp_early_core.c
@@ -10,7 +10,7 @@
 #include <asm/ebcdic.h>
 #include <asm/irq.h>
 #include <asm/sections.h>
-#include <asm/mem_detect.h>
+#include <asm/physmem_info.h>
 #include <asm/facility.h>
 #include "sclp.h"
 #include "sclp_rw.h"
@@ -336,7 +336,7 @@ int __init sclp_early_get_hsa_size(unsigned long *hsa_size)
 
 #define SCLP_STORAGE_INFO_FACILITY     0x0000400000000000UL
 
-void __weak __init add_mem_detect_block(u64 start, u64 end) {}
+void __weak __init add_physmem_online_range(u64 start, u64 end) {}
 int __init sclp_early_read_storage_info(void)
 {
 	struct read_storage_sccb *sccb = (struct read_storage_sccb *)sclp_early_sccb;
@@ -369,7 +369,7 @@ int __init sclp_early_read_storage_info(void)
 				if (!sccb->entries[sn])
 					continue;
 				rn = sccb->entries[sn] >> 16;
-				add_mem_detect_block((rn - 1) * rzm, rn * rzm);
+				add_physmem_online_range((rn - 1) * rzm, rn * rzm);
 			}
 			break;
 		case 0x0310:
@@ -382,6 +382,6 @@ int __init sclp_early_read_storage_info(void)
 
 	return 0;
 fail:
-	mem_detect.count = 0;
+	physmem_info.range_count = 0;
 	return -EIO;
 }