diff options
Diffstat (limited to 'arch/s390/mm/init.c')
| -rw-r--r-- | arch/s390/mm/init.c | 49 |
1 files changed, 45 insertions, 4 deletions
diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c index 94b8ba2ec85..0744fb3536b 100644 --- a/arch/s390/mm/init.c +++ b/arch/s390/mm/init.c @@ -42,9 +42,52 @@ DEFINE_PER_CPU(struct mmu_gather, mmu_gathers); pgd_t swapper_pg_dir[PTRS_PER_PGD] __attribute__((__aligned__(PAGE_SIZE))); -char empty_zero_page[PAGE_SIZE] __attribute__((__aligned__(PAGE_SIZE))); +unsigned long empty_zero_page, zero_page_mask; EXPORT_SYMBOL(empty_zero_page); +static unsigned long setup_zero_pages(void) +{ + struct cpuid cpu_id; + unsigned int order; + unsigned long size; + struct page *page; + int i; + + get_cpu_id(&cpu_id); + switch (cpu_id.machine) { + case 0x9672: /* g5 */ + case 0x2064: /* z900 */ + case 0x2066: /* z900 */ + case 0x2084: /* z990 */ + case 0x2086: /* z990 */ + case 0x2094: /* z9-109 */ + case 0x2096: /* z9-109 */ + order = 0; + break; + case 0x2097: /* z10 */ + case 0x2098: /* z10 */ + default: + order = 2; + break; + } + + 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--) { + SetPageReserved(page); + page++; + } + + size = PAGE_SIZE << order; + zero_page_mask = (size - 1) & PAGE_MASK; + + return 1UL << order; +} + /* * paging_init() sets up the page tables */ @@ -92,14 +135,12 @@ void __init mem_init(void) max_mapnr = num_physpages = max_low_pfn; high_memory = (void *) __va(max_low_pfn * PAGE_SIZE); - /* clear the zero-page */ - memset(empty_zero_page, 0, PAGE_SIZE); - /* Setup guest page hinting */ cmma_init(); /* this will put all low memory onto the freelists */ totalram_pages += free_all_bootmem(); + totalram_pages -= setup_zero_pages(); /* Setup zeroed pages. */ reservedpages = 0; |