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authorTang Chen <tangchen@cn.fujitsu.com>2013-11-12 15:08:02 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2013-11-13 12:09:08 +0900
commit0167d7d8b0beb4cf12076b47e4dc73897ae5acb0 (patch)
treec7430b0ad44e46fdb1537e1605d85d9e38028095 /arch/x86
parent79442ed189acb8b949662676e750eda173c06f9b (diff)
downloadlinux-linaro-stable-0167d7d8b0beb4cf12076b47e4dc73897ae5acb0.tar.gz
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>
Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/mm/init.c59
1 files changed, 39 insertions, 20 deletions
diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c
index ce32017c5e38..742d6d4ad9eb 100644
--- a/arch/x86/mm/init.c
+++ b/arch/x86/mm/init.c
@@ -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) {