1 files changed, 37 insertions, 0 deletions
diff --git a/arch/arm64/mm/ioremap.c b/arch/arm64/mm/ioremap.c
new file mode 100644
index 000000000..269f2f63a
--- /dev/null
+++ b/arch/arm64/mm/ioremap.c
@@ -0,0 +1,37 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <linux/mm.h>
+#include <linux/io.h>
+
+void __iomem *ioremap_prot(phys_addr_t phys_addr, size_t size,
+			   unsigned long prot)
+{
+	unsigned long last_addr = phys_addr + size - 1;
+
+	/* Don't allow outside PHYS_MASK */
+	if (last_addr & ~PHYS_MASK)
+		return NULL;
+
+	/* Don't allow RAM to be mapped. */
+	if (WARN_ON(pfn_is_map_memory(__phys_to_pfn(phys_addr))))
+		return NULL;
+
+	return generic_ioremap_prot(phys_addr, size, __pgprot(prot));
+}
+EXPORT_SYMBOL(ioremap_prot);
+
+/*
+ * Must be called after early_fixmap_init
+ */
+void __init early_ioremap_init(void)
+{
+	early_ioremap_setup();
+}
+
+bool arch_memremap_can_ram_remap(resource_size_t offset, size_t size,
+				 unsigned long flags)
+{
+	unsigned long pfn = PHYS_PFN(offset);
+
+	return pfn_is_map_memory(pfn);
+}