1 files changed, 81 insertions, 0 deletions
diff --git a/arch/loongarch/include/asm/io.h b/arch/loongarch/include/asm/io.h
new file mode 100644
index 000000000000..402a7d9e3a53
--- /dev/null
+++ b/arch/loongarch/include/asm/io.h
@@ -0,0 +1,81 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
+ */
+#ifndef _ASM_IO_H
+#define _ASM_IO_H
+
+#define ARCH_HAS_IOREMAP_WC
+
+#include <linux/kernel.h>
+#include <linux/types.h>
+
+#include <asm/addrspace.h>
+#include <asm/cpu.h>
+#include <asm/page.h>
+#include <asm/pgtable-bits.h>
+#include <asm/string.h>
+
+/*
+ * Change "struct page" to physical address.
+ */
+#define page_to_phys(page)	((phys_addr_t)page_to_pfn(page) << PAGE_SHIFT)
+
+extern void __init __iomem *early_ioremap(u64 phys_addr, unsigned long size);
+extern void __init early_iounmap(void __iomem *addr, unsigned long size);
+
+#define early_memremap early_ioremap
+#define early_memunmap early_iounmap
+
+#ifdef CONFIG_ARCH_IOREMAP
+
+static inline void __iomem *ioremap_prot(phys_addr_t offset, unsigned long size,
+					 unsigned long prot_val)
+{
+	if (prot_val & _CACHE_CC)
+		return (void __iomem *)(unsigned long)(CACHE_BASE + offset);
+	else
+		return (void __iomem *)(unsigned long)(UNCACHE_BASE + offset);
+}
+
+#define ioremap(offset, size)		\
+	ioremap_prot((offset), (size), pgprot_val(PAGE_KERNEL_SUC))
+
+#define iounmap(addr) 			((void)(addr))
+
+#endif
+
+/*
+ * On LoongArch, ioremap() has two variants, ioremap_wc() and ioremap_cache().
+ * They map bus memory into CPU space, the mapped memory is marked uncachable
+ * (_CACHE_SUC), uncachable but accelerated by write-combine (_CACHE_WUC) and
+ * cachable (_CACHE_CC) respectively for CPU access.
+ *
+ * @offset:    bus address of the memory
+ * @size:      size of the resource to map
+ */
+#define ioremap_wc(offset, size)	\
+	ioremap_prot((offset), (size), pgprot_val(PAGE_KERNEL_WUC))
+
+#define ioremap_cache(offset, size)	\
+	ioremap_prot((offset), (size), pgprot_val(PAGE_KERNEL))
+
+#define mmiowb() asm volatile ("dbar 0" ::: "memory")
+
+/*
+ * String version of I/O memory access operations.
+ */
+extern void __memset_io(volatile void __iomem *dst, int c, size_t count);
+extern void __memcpy_toio(volatile void __iomem *to, const void *from, size_t count);
+extern void __memcpy_fromio(void *to, const volatile void __iomem *from, size_t count);
+#define memset_io(c, v, l)     __memset_io((c), (v), (l))
+#define memcpy_fromio(a, c, l) __memcpy_fromio((a), (c), (l))
+#define memcpy_toio(c, a, l)   __memcpy_toio((c), (a), (l))
+
+#include <asm-generic/io.h>
+
+#define ARCH_HAS_VALID_PHYS_ADDR_RANGE
+extern int valid_phys_addr_range(phys_addr_t addr, size_t size);
+extern int valid_mmap_phys_addr_range(unsigned long pfn, size_t size);
+
+#endif /* _ASM_IO_H */