[PATCH v2 2/2] amr64: map FDT as RW for early_init_dt_scan()

[Hsin-Yi Wang]

Currently in arm64, FDT is mapped to RO before it's passed to
early_init_dt_scan(). However, there might be some code that needs
to modify FDT during init. Map FDT to RW until unflatten DT.

Signed-off-by: Hsin-Yi Wang <hsinyi@xxxxxxxxxxxx>
---
 arch/arm64/kernel/setup.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c
index 413d566405d1..08b22c1e72a9 100644
--- a/arch/arm64/kernel/setup.c
+++ b/arch/arm64/kernel/setup.c
@@ -179,9 +179,13 @@ static void __init smp_build_mpidr_hash(void)
 		pr_warn("Large number of MPIDR hash buckets detected\n");
 }
 
+extern void *__init __fixmap_remap_fdt(phys_addr_t dt_phys, int *size,
+				       pgprot_t prot);
+
 static void __init setup_machine_fdt(phys_addr_t dt_phys)
 {
-	void *dt_virt = fixmap_remap_fdt(dt_phys);
+	int size;
+	void *dt_virt = __fixmap_remap_fdt(dt_phys, &size, PAGE_KERNEL);
 	const char *name;
 
 	if (!dt_virt || !early_init_dt_scan(dt_virt)) {
@@ -320,6 +324,9 @@ void __init setup_arch(char **cmdline_p)
 	/* Parse the ACPI tables for possible boot-time configuration */
 	acpi_boot_table_init();
 
+	/* remap fdt to RO */
+	fixmap_remap_fdt(__fdt_pointer);
+
 	if (acpi_disabled)
 		unflatten_device_tree();
 
-- 
2.20.1