From: Steve Capper <steve.capper@arm.com>
Date: Mon, 4 Dec 2017 14:13:05 +0000
Subject: arm64: Initialise high_memory global variable earlier
Git-commit: f24e5834a2c3f6c5f814a417f858226f0a010ade
Patch-mainline: v4.15-rc4
References: bsc#1085535

The high_memory global variable is used by
cma_declare_contiguous(.) before it is defined.

We don't notice this as we compute __pa(high_memory - 1), and it looks
like we're processing a VA from the direct linear map.

This problem becomes apparent when we flip the kernel virtual address
space and the linear map is moved to the bottom of the kernel VA space.

This patch moves the initialisation of high_memory before it used.

Cc: <stable@vger.kernel.org>
Fixes: f7426b983a6a ("mm: cma: adjust address limit to avoid hitting low/high memory boundary")
Signed-off-by: Steve Capper <steve.capper@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Matthias Brugger <mbrugger@suse.com>
---
 arch/arm64/mm/init.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
index 5960bef0170d..00e7b900ca41 100644
--- a/arch/arm64/mm/init.c
+++ b/arch/arm64/mm/init.c
@@ -476,6 +476,8 @@ void __init arm64_memblock_init(void)
 
 	reserve_elfcorehdr();
 
+	high_memory = __va(memblock_end_of_DRAM() - 1) + 1;
+
 	dma_contiguous_reserve(arm64_dma_phys_limit);
 
 	memblock_allow_resize();
@@ -502,7 +504,6 @@ void __init bootmem_init(void)
 	sparse_init();
 	zone_sizes_init(min, max);
 
-	high_memory = __va((max << PAGE_SHIFT) - 1) + 1;
 	memblock_dump_all();
 }
 
-- 
2.16.2