[PATCH 5.15 059/230] s390/boot: allocate amode31 section in decompressor

Greg Kroah-Hartman
2022-07-11T09:45:28Z

From: Alexander Gordeev <agordeev@linux.ibm.com>

[ Upstream commit e3ec8e0f5711d73f7e5d5c3cffdf4fad4f1487b9 ]

The memory for amode31 section is allocated from the decompressed
kernel. Instead, allocate that memory from the decompressor. This
is a prerequisite to allow initialization of the virtual memory
before the decompressed kernel takes over.

Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/s390/boot/compressed/decompressor.h | 1 +
arch/s390/boot/startup.c | 8 ++++++++
arch/s390/kernel/entry.h | 1 +
arch/s390/kernel/setup.c | 22 +++++++++-------------
arch/s390/kernel/vmlinux.lds.S | 1 +
5 files changed, 20 insertions(+), 13 deletions(-)

diff --git a/arch/s390/boot/compressed/decompressor.h b/arch/s390/boot/compressed/decompressor.h
index a59f75c5b049..f75cc31a77dd 100644
--- a/arch/s390/boot/compressed/decompressor.h
+++ b/arch/s390/boot/compressed/decompressor.h
@@ -24,6 +24,7 @@ struct vmlinux_info {
unsigned long dynsym_start;
unsigned long rela_dyn_start;
unsigned long rela_dyn_end;
+ unsigned long amode31_size;
};

/* Symbols defined by linker scripts */
diff --git a/arch/s390/boot/startup.c b/arch/s390/boot/startup.c
index b13352dd1e1c..1aa11a8f57dd 100644
--- a/arch/s390/boot/startup.c
+++ b/arch/s390/boot/startup.c
@@ -15,6 +15,7 @@
#include "uv.h"

unsigned long __bootdata_preserved(__kaslr_offset);
+unsigned long __bootdata(__amode31_base);
unsigned long __bootdata_preserved(VMALLOC_START);
unsigned long __bootdata_preserved(VMALLOC_END);
struct page *__bootdata_preserved(vmemmap);
@@ -233,6 +234,12 @@ static void offset_vmlinux_info(unsigned long offset)
vmlinux.dynsym_start += offset;
}

+static unsigned long reserve_amode31(unsigned long safe_addr)
+{
+ __amode31_base = PAGE_ALIGN(safe_addr);
+ return safe_addr + vmlinux.amode31_size;
+}
+
void startup_kernel(void)
{
unsigned long random_lma;
@@ -247,6 +254,7 @@ void startup_kernel(void)
setup_lpp();
store_ipl_parmblock();
safe_addr = mem_safe_offset();
+ safe_addr = reserve_amode31(safe_addr);
safe_addr = read_ipl_report(safe_addr);
uv_query_info();
rescue_initrd(safe_addr);
diff --git a/arch/s390/kernel/entry.h b/arch/s390/kernel/entry.h
index 7f2696e8d511..6083090be1f4 100644
--- a/arch/s390/kernel/entry.h
+++ b/arch/s390/kernel/entry.h
@@ -70,5 +70,6 @@ extern struct exception_table_entry _stop_amode31_ex_table[];
#define __amode31_data __section(".amode31.data")
#define __amode31_ref __section(".amode31.refs")
extern long _start_amode31_refs[], _end_amode31_refs[];
+extern unsigned long __amode31_base;

#endif /* _ENTRY_H */
diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c
index 8ede12c4ba6b..e38de9e8ee13 100644
--- a/arch/s390/kernel/setup.c
+++ b/arch/s390/kernel/setup.c
@@ -95,10 +95,10 @@ EXPORT_SYMBOL(console_irq);
* relocated above 2 GB, because it has to use 31 bit addresses.
* Such code and data is part of the .amode31 section.
*/
-unsigned long __amode31_ref __samode31 = __pa(&_samode31);
-unsigned long __amode31_ref __eamode31 = __pa(&_eamode31);
-unsigned long __amode31_ref __stext_amode31 = __pa(&_stext_amode31);
-unsigned long __amode31_ref __etext_amode31 = __pa(&_etext_amode31);
+unsigned long __amode31_ref __samode31 = (unsigned long)&_samode31;
+unsigned long __amode31_ref __eamode31 = (unsigned long)&_eamode31;
+unsigned long __amode31_ref __stext_amode31 = (unsigned long)&_stext_amode31;
+unsigned long __amode31_ref __etext_amode31 = (unsigned long)&_etext_amode31;
struct exception_table_entry __amode31_ref *__start_amode31_ex_table = _start_amode31_ex_table;
struct exception_table_entry __amode31_ref *__stop_amode31_ex_table = _stop_amode31_ex_table;

@@ -149,6 +149,7 @@ struct mem_detect_info __bootdata(mem_detect);
struct initrd_data __bootdata(initrd_data);

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]);
@@ -800,6 +801,7 @@ static void __init reserve_kernel(void)

memblock_reserve(0, STARTUP_NORMAL_OFFSET);
memblock_reserve((unsigned long)sclp_early_sccb, EXT_SCCB_READ_SCP);
+ memblock_reserve(__amode31_base, __eamode31 - __samode31);
memblock_reserve((unsigned long)_stext, PFN_PHYS(start_pfn)
- (unsigned long)_stext);
}
@@ -820,20 +822,14 @@ static void __init setup_memory(void)

static void __init relocate_amode31_section(void)
{
- unsigned long amode31_addr, amode31_size;
- long amode31_offset;
+ unsigned long amode31_size = __eamode31 - __samode31;
+ long amode31_offset = __amode31_base - __samode31;
long *ptr;

- /* Allocate a new AMODE31 capable memory region */
- amode31_size = __eamode31 - __samode31;
pr_info("Relocating AMODE31 section of size 0x%08lx\n", amode31_size);
- amode31_addr = (unsigned long)memblock_alloc_low(amode31_size, PAGE_SIZE);
- if (!amode31_addr)
- panic("Failed to allocate memory for AMODE31 section\n");
- amode31_offset = amode31_addr - __samode31;

/* Move original AMODE31 section to the new one */
- memmove((void *)amode31_addr, (void *)__samode31, amode31_size);
+ memmove((void *)__amode31_base, (void *)__samode31, amode31_size);
/* Zero out the old AMODE31 section to catch invalid accesses within it */
memset((void *)__samode31, 0, amode31_size);

diff --git a/arch/s390/kernel/vmlinux.lds.S b/arch/s390/kernel/vmlinux.lds.S
index 63bdb9e1bfc1..42c43521878f 100644
--- a/arch/s390/kernel/vmlinux.lds.S
+++ b/arch/s390/kernel/vmlinux.lds.S
@@ -212,6 +212,7 @@ SECTIONS
QUAD(__dynsym_start) /* dynsym_start */
QUAD(__rela_dyn_start) /* rela_dyn_start */
QUAD(__rela_dyn_end) /* rela_dyn_end */
+ QUAD(_eamode31 - _samode31) /* amode31_size */
} :NONE

/* Debugging sections. */
--
2.35.1