1 files changed, 199 insertions, 0 deletions
diff --git a/arch/sh/include/asm/unaligned-sh4a.h b/arch/sh/include/asm/unaligned-sh4a.h
new file mode 100644
index 000000000..d311f00ed
--- /dev/null
+++ b/arch/sh/include/asm/unaligned-sh4a.h
@@ -0,0 +1,199 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __ASM_SH_UNALIGNED_SH4A_H
+#define __ASM_SH_UNALIGNED_SH4A_H
+
+/*
+ * SH-4A has support for unaligned 32-bit loads, and 32-bit loads only.
+ * Support for 64-bit accesses are done through shifting and masking
+ * relative to the endianness. Unaligned stores are not supported by the
+ * instruction encoding, so these continue to use the packed
+ * struct.
+ *
+ * The same note as with the movli.l/movco.l pair applies here, as long
+ * as the load is guaranteed to be inlined, nothing else will hook in to
+ * r0 and we get the return value for free.
+ *
+ * NOTE: Due to the fact we require r0 encoding, care should be taken to
+ * avoid mixing these heavily with other r0 consumers, such as the atomic
+ * ops. Failure to adhere to this can result in the compiler running out
+ * of spill registers and blowing up when building at low optimization
+ * levels. See http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34777.
+ */
+#include <linux/unaligned/packed_struct.h>
+#include <linux/types.h>
+#include <asm/byteorder.h>
+
+static inline u16 sh4a_get_unaligned_cpu16(const u8 *p)
+{
+#ifdef __LITTLE_ENDIAN
+	return p[0] | p[1] << 8;
+#else
+	return p[0] << 8 | p[1];
+#endif
+}
+
+static __always_inline u32 sh4a_get_unaligned_cpu32(const u8 *p)
+{
+	unsigned long unaligned;
+
+	__asm__ __volatile__ (
+		"movua.l	@%1, %0\n\t"
+		 : "=z" (unaligned)
+		 : "r" (p)
+	);
+
+	return unaligned;
+}
+
+/*
+ * Even though movua.l supports auto-increment on the read side, it can
+ * only store to r0 due to instruction encoding constraints, so just let
+ * the compiler sort it out on its own.
+ */
+static inline u64 sh4a_get_unaligned_cpu64(const u8 *p)
+{
+#ifdef __LITTLE_ENDIAN
+	return (u64)sh4a_get_unaligned_cpu32(p + 4) << 32 |
+		    sh4a_get_unaligned_cpu32(p);
+#else
+	return (u64)sh4a_get_unaligned_cpu32(p) << 32 |
+		    sh4a_get_unaligned_cpu32(p + 4);
+#endif
+}
+
+static inline u16 get_unaligned_le16(const void *p)
+{
+	return le16_to_cpu(sh4a_get_unaligned_cpu16(p));
+}
+
+static inline u32 get_unaligned_le32(const void *p)
+{
+	return le32_to_cpu(sh4a_get_unaligned_cpu32(p));
+}
+
+static inline u64 get_unaligned_le64(const void *p)
+{
+	return le64_to_cpu(sh4a_get_unaligned_cpu64(p));
+}
+
+static inline u16 get_unaligned_be16(const void *p)
+{
+	return be16_to_cpu(sh4a_get_unaligned_cpu16(p));
+}
+
+static inline u32 get_unaligned_be32(const void *p)
+{
+	return be32_to_cpu(sh4a_get_unaligned_cpu32(p));
+}
+
+static inline u64 get_unaligned_be64(const void *p)
+{
+	return be64_to_cpu(sh4a_get_unaligned_cpu64(p));
+}
+
+static inline void nonnative_put_le16(u16 val, u8 *p)
+{
+	*p++ = val;
+	*p++ = val >> 8;
+}
+
+static inline void nonnative_put_le32(u32 val, u8 *p)
+{
+	nonnative_put_le16(val, p);
+	nonnative_put_le16(val >> 16, p + 2);
+}
+
+static inline void nonnative_put_le64(u64 val, u8 *p)
+{
+	nonnative_put_le32(val, p);
+	nonnative_put_le32(val >> 32, p + 4);
+}
+
+static inline void nonnative_put_be16(u16 val, u8 *p)
+{
+	*p++ = val >> 8;
+	*p++ = val;
+}
+
+static inline void nonnative_put_be32(u32 val, u8 *p)
+{
+	nonnative_put_be16(val >> 16, p);
+	nonnative_put_be16(val, p + 2);
+}
+
+static inline void nonnative_put_be64(u64 val, u8 *p)
+{
+	nonnative_put_be32(val >> 32, p);
+	nonnative_put_be32(val, p + 4);
+}
+
+static inline void put_unaligned_le16(u16 val, void *p)
+{
+#ifdef __LITTLE_ENDIAN
+	__put_unaligned_cpu16(val, p);
+#else
+	nonnative_put_le16(val, p);
+#endif
+}
+
+static inline void put_unaligned_le32(u32 val, void *p)
+{
+#ifdef __LITTLE_ENDIAN
+	__put_unaligned_cpu32(val, p);
+#else
+	nonnative_put_le32(val, p);
+#endif
+}
+
+static inline void put_unaligned_le64(u64 val, void *p)
+{
+#ifdef __LITTLE_ENDIAN
+	__put_unaligned_cpu64(val, p);
+#else
+	nonnative_put_le64(val, p);
+#endif
+}
+
+static inline void put_unaligned_be16(u16 val, void *p)
+{
+#ifdef __BIG_ENDIAN
+	__put_unaligned_cpu16(val, p);
+#else
+	nonnative_put_be16(val, p);
+#endif
+}
+
+static inline void put_unaligned_be32(u32 val, void *p)
+{
+#ifdef __BIG_ENDIAN
+	__put_unaligned_cpu32(val, p);
+#else
+	nonnative_put_be32(val, p);
+#endif
+}
+
+static inline void put_unaligned_be64(u64 val, void *p)
+{
+#ifdef __BIG_ENDIAN
+	__put_unaligned_cpu64(val, p);
+#else
+	nonnative_put_be64(val, p);
+#endif
+}
+
+/*
+ * While it's a bit non-obvious, even though the generic le/be wrappers
+ * use the __get/put_xxx prefixing, they actually wrap in to the
+ * non-prefixed get/put_xxx variants as provided above.
+ */
+#include <linux/unaligned/generic.h>
+
+#ifdef __LITTLE_ENDIAN
+# define get_unaligned __get_unaligned_le
+# define put_unaligned __put_unaligned_le
+#else
+# define get_unaligned __get_unaligned_be
+# define put_unaligned __put_unaligned_be
+#endif
+
+#endif /* __ASM_SH_UNALIGNED_SH4A_H */