linux/arch/s390/mm/init.c
Heiko Carstens 34ad7cdc1b s390/mm: prevent memory offline for memory blocks with cma areas
Memory blocks that contain areas for the contiguous memory allocator
(cma) should not be allowed to go offline. Otherwise this would render
cma completely useless.
This might make sense on other architectures where memory might be
taken offline due to hardware errors, but not on architectures which
support memory hotplug for load balancing.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-08-09 09:09:28 -04:00

251 lines
6.1 KiB
C

/*
* S390 version
* Copyright IBM Corp. 1999
* Author(s): Hartmut Penner (hp@de.ibm.com)
*
* Derived from "arch/i386/mm/init.c"
* Copyright (C) 1995 Linus Torvalds
*/
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/types.h>
#include <linux/ptrace.h>
#include <linux/mman.h>
#include <linux/mm.h>
#include <linux/swap.h>
#include <linux/smp.h>
#include <linux/init.h>
#include <linux/pagemap.h>
#include <linux/bootmem.h>
#include <linux/memory.h>
#include <linux/pfn.h>
#include <linux/poison.h>
#include <linux/initrd.h>
#include <linux/export.h>
#include <linux/cma.h>
#include <linux/gfp.h>
#include <linux/memblock.h>
#include <asm/processor.h>
#include <linux/uaccess.h>
#include <asm/pgtable.h>
#include <asm/pgalloc.h>
#include <asm/dma.h>
#include <asm/lowcore.h>
#include <asm/tlb.h>
#include <asm/tlbflush.h>
#include <asm/sections.h>
#include <asm/ctl_reg.h>
#include <asm/sclp.h>
#include <asm/set_memory.h>
pgd_t swapper_pg_dir[PTRS_PER_PGD] __section(.bss..swapper_pg_dir);
unsigned long empty_zero_page, zero_page_mask;
EXPORT_SYMBOL(empty_zero_page);
EXPORT_SYMBOL(zero_page_mask);
static void __init setup_zero_pages(void)
{
unsigned int order;
struct page *page;
int i;
/* Latest machines require a mapping granularity of 512KB */
order = 7;
/* Limit number of empty zero pages for small memory sizes */
while (order > 2 && (totalram_pages >> 10) < (1UL << order))
order--;
empty_zero_page = __get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
if (!empty_zero_page)
panic("Out of memory in setup_zero_pages");
page = virt_to_page((void *) empty_zero_page);
split_page(page, order);
for (i = 1 << order; i > 0; i--) {
mark_page_reserved(page);
page++;
}
zero_page_mask = ((PAGE_SIZE << order) - 1) & PAGE_MASK;
}
/*
* paging_init() sets up the page tables
*/
void __init paging_init(void)
{
unsigned long max_zone_pfns[MAX_NR_ZONES];
unsigned long pgd_type, asce_bits;
psw_t psw;
init_mm.pgd = swapper_pg_dir;
if (VMALLOC_END > _REGION2_SIZE) {
asce_bits = _ASCE_TYPE_REGION2 | _ASCE_TABLE_LENGTH;
pgd_type = _REGION2_ENTRY_EMPTY;
} else {
asce_bits = _ASCE_TYPE_REGION3 | _ASCE_TABLE_LENGTH;
pgd_type = _REGION3_ENTRY_EMPTY;
}
init_mm.context.asce = (__pa(init_mm.pgd) & PAGE_MASK) | asce_bits;
S390_lowcore.kernel_asce = init_mm.context.asce;
crst_table_init((unsigned long *) init_mm.pgd, pgd_type);
vmem_map_init();
/* enable virtual mapping in kernel mode */
__ctl_load(S390_lowcore.kernel_asce, 1, 1);
__ctl_load(S390_lowcore.kernel_asce, 7, 7);
__ctl_load(S390_lowcore.kernel_asce, 13, 13);
psw.mask = __extract_psw();
psw_bits(psw).dat = 1;
psw_bits(psw).as = PSW_BITS_AS_HOME;
__load_psw_mask(psw.mask);
sparse_memory_present_with_active_regions(MAX_NUMNODES);
sparse_init();
memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
max_zone_pfns[ZONE_DMA] = PFN_DOWN(MAX_DMA_ADDRESS);
max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
free_area_init_nodes(max_zone_pfns);
}
void mark_rodata_ro(void)
{
unsigned long size = __end_ro_after_init - __start_ro_after_init;
set_memory_ro((unsigned long)__start_ro_after_init, size >> PAGE_SHIFT);
pr_info("Write protected read-only-after-init data: %luk\n", size >> 10);
}
void __init mem_init(void)
{
cpumask_set_cpu(0, &init_mm.context.cpu_attach_mask);
cpumask_set_cpu(0, mm_cpumask(&init_mm));
set_max_mapnr(max_low_pfn);
high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
/* Setup guest page hinting */
cmma_init();
/* this will put all low memory onto the freelists */
free_all_bootmem();
setup_zero_pages(); /* Setup zeroed pages. */
cmma_init_nodat();
mem_init_print_info(NULL);
}
void free_initmem(void)
{
__set_memory((unsigned long) _sinittext,
(_einittext - _sinittext) >> PAGE_SHIFT,
SET_MEMORY_RW | SET_MEMORY_NX);
free_initmem_default(POISON_FREE_INITMEM);
}
#ifdef CONFIG_BLK_DEV_INITRD
void __init free_initrd_mem(unsigned long start, unsigned long end)
{
free_reserved_area((void *)start, (void *)end, POISON_FREE_INITMEM,
"initrd");
}
#endif
unsigned long memory_block_size_bytes(void)
{
/*
* Make sure the memory block size is always greater
* or equal than the memory increment size.
*/
return max_t(unsigned long, MIN_MEMORY_BLOCK_SIZE, sclp.rzm);
}
#ifdef CONFIG_MEMORY_HOTPLUG
#ifdef CONFIG_CMA
/* Prevent memory blocks which contain cma regions from going offline */
struct s390_cma_mem_data {
unsigned long start;
unsigned long end;
};
static int s390_cma_check_range(struct cma *cma, void *data)
{
struct s390_cma_mem_data *mem_data;
unsigned long start, end;
mem_data = data;
start = cma_get_base(cma);
end = start + cma_get_size(cma);
if (end < mem_data->start)
return 0;
if (start >= mem_data->end)
return 0;
return -EBUSY;
}
static int s390_cma_mem_notifier(struct notifier_block *nb,
unsigned long action, void *data)
{
struct s390_cma_mem_data mem_data;
struct memory_notify *arg;
int rc = 0;
arg = data;
mem_data.start = arg->start_pfn << PAGE_SHIFT;
mem_data.end = mem_data.start + (arg->nr_pages << PAGE_SHIFT);
if (action == MEM_GOING_OFFLINE)
rc = cma_for_each_area(s390_cma_check_range, &mem_data);
return notifier_from_errno(rc);
}
static struct notifier_block s390_cma_mem_nb = {
.notifier_call = s390_cma_mem_notifier,
};
static int __init s390_cma_mem_init(void)
{
return register_memory_notifier(&s390_cma_mem_nb);
}
device_initcall(s390_cma_mem_init);
#endif /* CONFIG_CMA */
int arch_add_memory(int nid, u64 start, u64 size, bool want_memblock)
{
unsigned long start_pfn = PFN_DOWN(start);
unsigned long size_pages = PFN_DOWN(size);
int rc;
rc = vmem_add_mapping(start, size);
if (rc)
return rc;
rc = __add_pages(nid, start_pfn, size_pages, want_memblock);
if (rc)
vmem_remove_mapping(start, size);
return rc;
}
#ifdef CONFIG_MEMORY_HOTREMOVE
int arch_remove_memory(u64 start, u64 size)
{
/*
* There is no hardware or firmware interface which could trigger a
* hot memory remove on s390. So there is nothing that needs to be
* implemented.
*/
return -EBUSY;
}
#endif
#endif /* CONFIG_MEMORY_HOTPLUG */