[PATCH] arm64: mm: ignore memory above supported physical address size
Kristina Martsenko
kristina.martsenko at arm.com
Thu Jan 18 11:13:11 PST 2018
When booting a kernel without 52-bit PA support (e.g. a kernel with 4k
pages) on a system with 52-bit memory, the kernel will currently try to
use the 52-bit memory and crash. Fix this by ignoring any memory higher
than what the kernel supports.
Fixes: f77d281713d4 ("arm64: enable 52-bit physical address support")
Signed-off-by: Kristina Martsenko <kristina.martsenko at arm.com>
---
arch/arm64/mm/init.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
index 672094ed7e07..285745b2ca38 100644
--- a/arch/arm64/mm/init.c
+++ b/arch/arm64/mm/init.c
@@ -366,6 +366,9 @@ void __init arm64_memblock_init(void)
/* Handle linux,usable-memory-range property */
fdt_enforce_memory_region();
+ /* Remove memory above our supported physical address size */
+ memblock_remove(1ULL << PHYS_MASK_SHIFT, ULLONG_MAX);
+
/*
* Ensure that the linear region takes up exactly half of the kernel
* virtual address space. This way, we can distinguish a linear address
--
2.1.4
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