This is a note to let you know that I've just added the patch titled
s390/boot: always align vmalloc area on segment boundary
to the 6.6-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
s390-boot-always-align-vmalloc-area-on-segment-bound.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit c041e16276a4461286d89f2f2ad9ed72fac38954
Author: Alexander Gordeev <agordeev@xxxxxxxxxxxxx>
Date: Sun Jul 16 10:56:00 2023 +0200
s390/boot: always align vmalloc area on segment boundary
[ Upstream commit 65f8780e2d70257200547b5a7654974aa7c37ce1 ]
The size of vmalloc area depends from various factors
on boot and could be set to:
1. Default size as determined by VMALLOC_DEFAULT_SIZE macro;
2. One half of the virtual address space not occupied by
modules and fixed mappings;
3. The size provided by user with vmalloc= kernel command
line parameter;
In cases [1] and [2] the vmalloc area base address is aligned
on Region3 table type boundary, while in case [3] in might get
aligned on page boundary.
Limit the waste of page tables and always align vmalloc area
size and base address on segment boundary.
Acked-by: Heiko Carstens <hca@xxxxxxxxxxxxx>
Signed-off-by: Alexander Gordeev <agordeev@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/arch/s390/boot/ipl_parm.c b/arch/s390/boot/ipl_parm.c
index 7b7521762633..4230144645bc 100644
--- a/arch/s390/boot/ipl_parm.c
+++ b/arch/s390/boot/ipl_parm.c
@@ -272,7 +272,7 @@ void parse_boot_command_line(void)
memory_limit = round_down(memparse(val, NULL), PAGE_SIZE);
if (!strcmp(param, "vmalloc") && val) {
- vmalloc_size = round_up(memparse(val, NULL), PAGE_SIZE);
+ vmalloc_size = round_up(memparse(val, NULL), _SEGMENT_SIZE);
vmalloc_size_set = 1;
}
diff --git a/arch/s390/boot/startup.c b/arch/s390/boot/startup.c
index d3e48bd9c394..d08db5df6091 100644
--- a/arch/s390/boot/startup.c
+++ b/arch/s390/boot/startup.c
@@ -212,7 +212,8 @@ static unsigned long setup_kernel_memory_layout(void)
VMALLOC_END = MODULES_VADDR;
/* allow vmalloc area to occupy up to about 1/2 of the rest virtual space left */
- vmalloc_size = min(vmalloc_size, round_down(VMALLOC_END / 2, _REGION3_SIZE));
+ vsize = round_down(VMALLOC_END / 2, _SEGMENT_SIZE);
+ vmalloc_size = min(vmalloc_size, vsize);
VMALLOC_START = VMALLOC_END - vmalloc_size;
/* split remaining virtual space between 1:1 mapping & vmemmap array */
