1 files changed, 64 insertions, 0 deletions
diff --git a/arch/arc/mm/ioremap.c b/arch/arc/mm/ioremap.c
new file mode 100644
index 0000000000..b07004d532
--- /dev/null
+++ b/arch/arc/mm/ioremap.c
@@ -0,0 +1,64 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
+ */
+
+#include <linux/vmalloc.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/io.h>
+#include <linux/mm.h>
+#include <linux/cache.h>
+
+static inline bool arc_uncached_addr_space(phys_addr_t paddr)
+{
+	if (is_isa_arcompact()) {
+		if (paddr >= ARC_UNCACHED_ADDR_SPACE)
+			return true;
+	} else if (paddr >= perip_base && paddr <= perip_end) {
+		return true;
+	}
+
+	return false;
+}
+
+void __iomem *ioremap(phys_addr_t paddr, unsigned long size)
+{
+	/*
+	 * If the region is h/w uncached, MMU mapping can be elided as optim
+	 * The cast to u32 is fine as this region can only be inside 4GB
+	 */
+	if (arc_uncached_addr_space(paddr))
+		return (void __iomem *)(u32)paddr;
+
+	return ioremap_prot(paddr, size,
+			    pgprot_val(pgprot_noncached(PAGE_KERNEL)));
+}
+EXPORT_SYMBOL(ioremap);
+
+/*
+ * ioremap with access flags
+ * Cache semantics wise it is same as ioremap - "forced" uncached.
+ * However unlike vanilla ioremap which bypasses ARC MMU for addresses in
+ * ARC hardware uncached region, this one still goes thru the MMU as caller
+ * might need finer access control (R/W/X)
+ */
+void __iomem *ioremap_prot(phys_addr_t paddr, size_t size,
+			   unsigned long flags)
+{
+	pgprot_t prot = __pgprot(flags);
+
+	/* force uncached */
+	return generic_ioremap_prot(paddr, size, pgprot_noncached(prot));
+}
+EXPORT_SYMBOL(ioremap_prot);
+
+void iounmap(volatile void __iomem *addr)
+{
+	/* weird double cast to handle phys_addr_t > 32 bits */
+	if (arc_uncached_addr_space((phys_addr_t)(u32)addr))
+		return;
+
+	generic_iounmap(addr);
+}
+EXPORT_SYMBOL(iounmap);