1 files changed, 94 insertions, 0 deletions
diff --git a/arch/ia64/mm/ioremap.c b/arch/ia64/mm/ioremap.c
new file mode 100644
index 0000000000..711b6abc82
--- /dev/null
+++ b/arch/ia64/mm/ioremap.c
@@ -0,0 +1,94 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * (c) Copyright 2006, 2007 Hewlett-Packard Development Company, L.P.
+ *	Bjorn Helgaas <bjorn.helgaas@hp.com>
+ */
+
+#include <linux/compiler.h>
+#include <linux/module.h>
+#include <linux/efi.h>
+#include <linux/io.h>
+#include <linux/mm.h>
+#include <linux/vmalloc.h>
+#include <asm/io.h>
+#include <asm/meminit.h>
+
+static inline void __iomem *
+__ioremap_uc(unsigned long phys_addr)
+{
+	return (void __iomem *) (__IA64_UNCACHED_OFFSET | phys_addr);
+}
+
+void __iomem *
+early_ioremap (unsigned long phys_addr, unsigned long size)
+{
+	u64 attr;
+	attr = kern_mem_attribute(phys_addr, size);
+	if (attr & EFI_MEMORY_WB)
+		return (void __iomem *) phys_to_virt(phys_addr);
+	return __ioremap_uc(phys_addr);
+}
+
+void __iomem *ioremap_prot(phys_addr_t phys_addr, size_t size,
+			   unsigned long flags)
+{
+	u64 attr;
+	unsigned long gran_base, gran_size;
+	unsigned long page_base;
+
+	/*
+	 * For things in kern_memmap, we must use the same attribute
+	 * as the rest of the kernel.  For more details, see
+	 * Documentation/arch/ia64/aliasing.rst.
+	 */
+	attr = kern_mem_attribute(phys_addr, size);
+	if (attr & EFI_MEMORY_WB)
+		return (void __iomem *) phys_to_virt(phys_addr);
+	else if (attr & EFI_MEMORY_UC)
+		return __ioremap_uc(phys_addr);
+
+	/*
+	 * Some chipsets don't support UC access to memory.  If
+	 * WB is supported for the whole granule, we prefer that.
+	 */
+	gran_base = GRANULEROUNDDOWN(phys_addr);
+	gran_size = GRANULEROUNDUP(phys_addr + size) - gran_base;
+	if (efi_mem_attribute(gran_base, gran_size) & EFI_MEMORY_WB)
+		return (void __iomem *) phys_to_virt(phys_addr);
+
+	/*
+	 * WB is not supported for the whole granule, so we can't use
+	 * the region 7 identity mapping.  If we can safely cover the
+	 * area with kernel page table mappings, we can use those
+	 * instead.
+	 */
+	page_base = phys_addr & PAGE_MASK;
+	size = PAGE_ALIGN(phys_addr + size) - page_base;
+	if (efi_mem_attribute(page_base, size) & EFI_MEMORY_WB)
+		return generic_ioremap_prot(phys_addr, size, __pgprot(flags));
+
+	return __ioremap_uc(phys_addr);
+}
+EXPORT_SYMBOL(ioremap_prot);
+
+void __iomem *
+ioremap_uc(unsigned long phys_addr, unsigned long size)
+{
+	if (kern_mem_attribute(phys_addr, size) & EFI_MEMORY_WB)
+		return NULL;
+
+	return __ioremap_uc(phys_addr);
+}
+EXPORT_SYMBOL(ioremap_uc);
+
+void
+early_iounmap (volatile void __iomem *addr, unsigned long size)
+{
+}
+
+void iounmap(volatile void __iomem *addr)
+{
+	if (REGION_NUMBER(addr) == RGN_GATE)
+		vunmap((void *) ((unsigned long) addr & PAGE_MASK));
+}
+EXPORT_SYMBOL(iounmap);