From b05b9f5f9dcf593a0e9327676b78e6c17b4218e8 Mon Sep 17 00:00:00 2001
From: Tony Luck <tony.luck@intel.com>
Date: Wed, 24 Jun 2015 16:58:15 -0700
Subject: x86, mirror: x86 enabling - find mirrored memory ranges

UEFI GetMemoryMap() uses a new attribute bit to mark mirrored memory
address ranges.  See UEFI 2.5 spec pages 157-158:

  http://www.uefi.org/sites/default/files/resources/UEFI%202_5.pdf

On EFI enabled systems scan the memory map and tell memblock about any
mirrored ranges.

Signed-off-by: Tony Luck <tony.luck@intel.com>
Cc: Xishi Qiu <qiuxishi@huawei.com>
Cc: Hanjun Guo <guohanjun@huawei.com>
Cc: Xiexiuqi <xiexiuqi@huawei.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
 arch/x86/kernel/setup.c     |  3 +++
 arch/x86/platform/efi/efi.c | 21 +++++++++++++++++++++
 2 files changed, 24 insertions(+)

(limited to 'arch/x86')

diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index 39ca113676fe..d3b95b89e9b2 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -1105,6 +1105,9 @@ void __init setup_arch(char **cmdline_p)
 	memblock_set_current_limit(ISA_END_ADDRESS);
 	memblock_x86_fill();
 
+	if (efi_enabled(EFI_BOOT))
+		efi_find_mirror();
+
 	/*
 	 * The EFI specification says that boot service code won't be called
 	 * after ExitBootServices(). This is, in fact, a lie.
diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
index 3b984c3aa1b0..c1c382c58c60 100644
--- a/arch/x86/platform/efi/efi.c
+++ b/arch/x86/platform/efi/efi.c
@@ -117,6 +117,27 @@ void efi_get_time(struct timespec *now)
 	now->tv_nsec = 0;
 }
 
+void __init efi_find_mirror(void)
+{
+	void *p;
+	u64 mirror_size = 0, total_size = 0;
+
+	for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
+		efi_memory_desc_t *md = p;
+		unsigned long long start = md->phys_addr;
+		unsigned long long size = md->num_pages << EFI_PAGE_SHIFT;
+
+		total_size += size;
+		if (md->attribute & EFI_MEMORY_MORE_RELIABLE) {
+			memblock_mark_mirror(start, size);
+			mirror_size += size;
+		}
+	}
+	if (mirror_size)
+		pr_info("Memory: %lldM/%lldM mirrored memory\n",
+			mirror_size>>20, total_size>>20);
+}
+
 /*
  * Tell the kernel about the EFI memory map.  This might include
  * more than the max 128 entries that can fit in the e820 legacy
-- 
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