Commit 65f8780e authored by Alexander Gordeev's avatar Alexander Gordeev
Browse files

s390/boot: always align vmalloc area on segment boundary 



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: default avatarHeiko Carstens <hca@linux.ibm.com>
Signed-off-by: default avatarAlexander Gordeev <agordeev@linux.ibm.com>
parent d12292fd

arch/s390/boot/ipl_parm.c

+1 −1
Original line number Diff line number Diff line
@@ -274,7 +274,7 @@ 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;

		}

arch/s390/boot/startup.c

+2 −1
Original line number Diff line number Diff line
@@ -255,7 +255,8 @@ 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 */