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x86/mm: factor out of top-down direct mapping setup 

Create a new function memory_map_top_down to factor out of the top-down
direct memory mapping pagetable setup.  This is also a preparation for the
following patch, which will introduce the bottom-up memory mapping.  That
said, we will put the two ways of pagetable setup into separate functions,
and choose to use which way in init_mem_mapping, which makes the code more
clear.

Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com>
Signed-off-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Toshi Kani <toshi.kani@hp.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Cc: Thomas Renninger <trenn@suse.de>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Jiang Liu <jiang.liu@huawei.com>
Cc: Wen Congyang <wency@cn.fujitsu.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: Taku Izumi <izumi.taku@jp.fujitsu.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Tang Chen 2013-11-12 15:08:02 -08:00 committed by Linus Torvalds
parent 79442ed189
commit 0167d7d8b0
1 changed files with 39 additions and 20 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

59
arch/x86/mm/init.c
View File

@ -418,27 +418,27 @@ static unsigned long __init get_new_step_size(unsigned long step_size)
return step_size << 5;
}
void __init init_mem_mapping(void)
/**
* memory_map_top_down - Map [map_start, map_end) top down
* @map_start: start address of the target memory range
* @map_end: end address of the target memory range
*
* This function will setup direct mapping for memory range
* [map_start, map_end) in top-down. That said, the page tables
* will be allocated at the end of the memory, and we map the
* memory in top-down.
*/
static void __init memory_map_top_down(unsigned long map_start,
unsigned long map_end)
{
unsigned long end, real_end, start, last_start;
unsigned long real_end, start, last_start;
unsigned long step_size;
unsigned long addr;
unsigned long mapped_ram_size = 0;
unsigned long new_mapped_ram_size;
probe_page_size_mask();
#ifdef CONFIG_X86_64
end = max_pfn << PAGE_SHIFT;
#else
end = max_low_pfn << PAGE_SHIFT;
#endif
/* the ISA range is always mapped regardless of memory holes */
init_memory_mapping(0, ISA_END_ADDRESS);
/* xen has big range in reserved near end of ram, skip it at first.*/
addr = memblock_find_in_range(ISA_END_ADDRESS, end, PMD_SIZE, PMD_SIZE);
addr = memblock_find_in_range(map_start, map_end, PMD_SIZE, PMD_SIZE);
real_end = addr + PMD_SIZE;
/* step_size need to be small so pgt_buf from BRK could cover it */
@ -453,13 +453,13 @@ void __init init_mem_mapping(void)
* end of RAM in [min_pfn_mapped, max_pfn_mapped) used as new pages
* for page table.
*/
while (last_start > ISA_END_ADDRESS) {
while (last_start > map_start) {
if (last_start > step_size) {
start = round_down(last_start - 1, step_size);
if (start < ISA_END_ADDRESS)
start = ISA_END_ADDRESS;
if (start < map_start)
start = map_start;
} else
start = ISA_END_ADDRESS;
start = map_start;
new_mapped_ram_size = init_range_memory_mapping(start,
last_start);
last_start = start;
@ -470,8 +470,27 @@ void __init init_mem_mapping(void)
mapped_ram_size += new_mapped_ram_size;
}
if (real_end < end)
init_range_memory_mapping(real_end, end);
if (real_end < map_end)
init_range_memory_mapping(real_end, map_end);
}
void __init init_mem_mapping(void)
{
unsigned long end;
probe_page_size_mask();
#ifdef CONFIG_X86_64
end = max_pfn << PAGE_SHIFT;
#else
end = max_low_pfn << PAGE_SHIFT;
#endif
/* the ISA range is always mapped regardless of memory holes */
init_memory_mapping(0, ISA_END_ADDRESS);
/* setup direct mapping for range [ISA_END_ADDRESS, end) in top-down*/
memory_map_top_down(ISA_END_ADDRESS, end);
#ifdef CONFIG_X86_64
if (max_pfn > max_low_pfn) {