diff options
Diffstat (limited to 'arch/x86/mm/init.c')
| -rw-r--r-- | arch/x86/mm/init.c | 34 |
1 files changed, 34 insertions, 0 deletions
diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c index 2393d0099e7f..848189229b2d 100644 --- a/arch/x86/mm/init.c +++ b/arch/x86/mm/init.c @@ -17,10 +17,44 @@ #include <asm/proto.h> #include <asm/dma.h> /* for MAX_DMA_PFN */ +#include "mm_internal.h" + unsigned long __initdata pgt_buf_start; unsigned long __meminitdata pgt_buf_end; unsigned long __meminitdata pgt_buf_top; +__ref void *alloc_low_page(void) +{ + unsigned long pfn; + void *adr; + +#ifdef CONFIG_X86_64 + if (after_bootmem) { + adr = (void *)get_zeroed_page(GFP_ATOMIC | __GFP_NOTRACK); + + return adr; + } +#endif + + if ((pgt_buf_end + 1) >= pgt_buf_top) { + unsigned long ret; + if (min_pfn_mapped >= max_pfn_mapped) + panic("alloc_low_page: ran out of memory"); + ret = memblock_find_in_range(min_pfn_mapped << PAGE_SHIFT, + max_pfn_mapped << PAGE_SHIFT, + PAGE_SIZE, PAGE_SIZE); + if (!ret) + panic("alloc_low_page: can not alloc memory"); + memblock_reserve(ret, PAGE_SIZE); + pfn = ret >> PAGE_SHIFT; + } else + pfn = pgt_buf_end++; + + adr = __va(pfn * PAGE_SIZE); + clear_page(adr); + return adr; +} + /* need 4 4k for initial PMD_SIZE, 4k for 0-ISA_END_ADDRESS */ #define INIT_PGT_BUF_SIZE (5 * PAGE_SIZE) RESERVE_BRK(early_pgt_alloc, INIT_PGT_BUF_SIZE); |