diff options
| author | Shaohui Zheng <shaohui.zheng@intel.com> | 2010-02-02 13:44:16 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2010-02-02 18:11:23 -0800 |
| commit | ea0854170c95245a258b386c7a9314399c949fe0 (patch) | |
| tree | 59a7ec7cbe8200fd79dc4a7188958c2d5cbef5b7 /arch | |
| parent | a225a5cc2c25e1217e68ee2ab8dd4454573fa308 (diff) | |
memory hotplug: fix a bug on /dev/mem for 64-bit kernels
Newly added memory can not be accessed via /dev/mem, because we do not
update the variables high_memory, max_pfn and max_low_pfn.
Add a function update_end_of_memory_vars() to update these variables for
64-bit kernels.
[akpm@linux-foundation.org: simplify comment]
Signed-off-by: Shaohui Zheng <shaohui.zheng@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Li Haicheng <haicheng.li@intel.com>
Reviewed-by: Wu Fengguang <fengguang.wu@intel.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/mm/init_64.c | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c index 5198b9bb34ef..69ddfbd91135 100644 --- a/arch/x86/mm/init_64.c +++ b/arch/x86/mm/init_64.c @@ -49,6 +49,7 @@ #include <asm/numa.h> #include <asm/cacheflush.h> #include <asm/init.h> +#include <linux/bootmem.h> static unsigned long dma_reserve __initdata; @@ -616,6 +617,21 @@ void __init paging_init(void) */ #ifdef CONFIG_MEMORY_HOTPLUG /* + * After memory hotplug the variables max_pfn, max_low_pfn and high_memory need + * updating. + */ +static void update_end_of_memory_vars(u64 start, u64 size) +{ + unsigned long end_pfn = PFN_UP(start + size); + + if (end_pfn > max_pfn) { + max_pfn = end_pfn; + max_low_pfn = end_pfn; + high_memory = (void *)__va(max_pfn * PAGE_SIZE - 1) + 1; + } +} + +/* * Memory is added always to NORMAL zone. This means you will never get * additional DMA/DMA32 memory. */ @@ -634,6 +650,9 @@ int arch_add_memory(int nid, u64 start, u64 size) ret = __add_pages(nid, zone, start_pfn, nr_pages); WARN_ON_ONCE(ret); + /* update max_pfn, max_low_pfn and high_memory */ + update_end_of_memory_vars(start, size); + return ret; } EXPORT_SYMBOL_GPL(arch_add_memory); |