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>
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@ -49,6 +49,7 @@
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#include <asm/numa.h>
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#include <asm/numa.h>
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#include <asm/cacheflush.h>
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#include <asm/cacheflush.h>
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#include <asm/init.h>
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#include <asm/init.h>
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#include <linux/bootmem.h>
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static unsigned long dma_reserve __initdata;
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static unsigned long dma_reserve __initdata;
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@ -615,6 +616,21 @@ void __init paging_init(void)
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* Memory hotplug specific functions
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* Memory hotplug specific functions
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*/
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*/
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#ifdef CONFIG_MEMORY_HOTPLUG
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#ifdef CONFIG_MEMORY_HOTPLUG
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/*
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* After memory hotplug the variables max_pfn, max_low_pfn and high_memory need
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* updating.
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*/
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static void update_end_of_memory_vars(u64 start, u64 size)
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{
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unsigned long end_pfn = PFN_UP(start + size);
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if (end_pfn > max_pfn) {
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max_pfn = end_pfn;
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max_low_pfn = end_pfn;
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high_memory = (void *)__va(max_pfn * PAGE_SIZE - 1) + 1;
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}
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}
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/*
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/*
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* Memory is added always to NORMAL zone. This means you will never get
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* Memory is added always to NORMAL zone. This means you will never get
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* additional DMA/DMA32 memory.
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* additional DMA/DMA32 memory.
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@ -634,6 +650,9 @@ int arch_add_memory(int nid, u64 start, u64 size)
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ret = __add_pages(nid, zone, start_pfn, nr_pages);
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ret = __add_pages(nid, zone, start_pfn, nr_pages);
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WARN_ON_ONCE(ret);
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WARN_ON_ONCE(ret);
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/* update max_pfn, max_low_pfn and high_memory */
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update_end_of_memory_vars(start, size);
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return ret;
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return ret;
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}
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}
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EXPORT_SYMBOL_GPL(arch_add_memory);
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EXPORT_SYMBOL_GPL(arch_add_memory);
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