[RFC/PATCH 4/5] arm64: Add support for arch_memremap_ro()

[Stephen Boyd]

Pass in PAGE_KERNEL_RO to the underlying IO mapping mechanism to get a
read-only mapping for the MEMREMAP_RO type of memory mappings that
memremap() supports.

Cc: Evan Green <evgreen@xxxxxxxxxxxx>
Cc: Rob Herring <robh+dt@xxxxxxxxxx>
Cc: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
Cc: Andy Gross <agross@xxxxxxxxxx>
Cc: Will Deacon <will.deacon@xxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
Signed-off-by: Stephen Boyd <swboyd@xxxxxxxxxxxx>
---
 arch/arm64/include/asm/io.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm64/include/asm/io.h b/arch/arm64/include/asm/io.h
index 8bb7210ac286..245bd371e8dc 100644
--- a/arch/arm64/include/asm/io.h
+++ b/arch/arm64/include/asm/io.h
@@ -185,6 +185,7 @@ extern void __iomem *ioremap_cache(phys_addr_t phys_addr, size_t size);
 #define ioremap_nocache(addr, size)	__ioremap((addr), (size), __pgprot(PROT_DEVICE_nGnRE))
 #define ioremap_wc(addr, size)		__ioremap((addr), (size), __pgprot(PROT_NORMAL_NC))
 #define ioremap_wt(addr, size)		__ioremap((addr), (size), __pgprot(PROT_DEVICE_nGnRE))
+#define arch_memremap_ro(addr, size)	__ioremap((addr), (size), PAGE_KERNEL_RO)
 #define iounmap				__iounmap
 
 /*
-- 
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