[PATCH 2/4] arm: 64-bit device specific operation

[Renaud Barbier <renaud.barbier@abaco.com>]

In preparation for the introduction of the NXP FSL IFC
nand driver, add memcpy_ directional I/O operation.

Code based on NXP Linux support:
git://source.codeaurora.org/external/qoriq/qoriq-components/linux

Signed-off-by: Renaud Barbier <renaud.barbier@abaco.com>
---
 arch/arm/lib64/Makefile |  2 +-
 arch/arm/lib64/io.c     | 98 +++++++++++++++++++++++++++++++++++++++++
 2 files changed, 99 insertions(+), 1 deletion(-)
 create mode 100644 arch/arm/lib64/io.c

diff --git a/arch/arm/lib64/Makefile b/arch/arm/lib64/Makefile
index 69cb3d8ea1..591727c160 100644
--- a/arch/arm/lib64/Makefile
+++ b/arch/arm/lib64/Makefile
@@ -1,4 +1,4 @@
-obj-y += stacktrace.o
+obj-y += stacktrace.o io.o
 obj-$(CONFIG_ARM_LINUX)	+= armlinux.o
 obj-y	+= div0.o
 obj-$(CONFIG_ARM_OPTIMZED_STRING_FUNCTIONS)	+= memcpy.o
diff --git a/arch/arm/lib64/io.c b/arch/arm/lib64/io.c
new file mode 100644
index 0000000000..693cda42b0
--- /dev/null
+++ b/arch/arm/lib64/io.c
@@ -0,0 +1,98 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Based on arch/arm/kernel/io.c
+ *
+ * Copyright (C) 2012 ARM Ltd.
+ */
+
+#include <module.h>
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <io.h>
+
+/*
+ * Copy data from IO memory space to "real" memory space.
+ */
+void memcpy_fromio(void *to, const volatile void __iomem *from, size_t count)
+{
+	while (count && !IS_ALIGNED((unsigned long)from, 8)) {
+		*(u8 *)to = __raw_readb(from);
+		from++;
+		to++;
+		count--;
+	}
+
+	while (count >= 8) {
+		*(u64 *)to = __raw_readq(from);
+		from += 8;
+		to += 8;
+		count -= 8;
+	}
+
+	while (count) {
+		*(u8 *)to = __raw_readb(from);
+		from++;
+		to++;
+		count--;
+	}
+}
+EXPORT_SYMBOL(memcpy_fromio);
+
+/*
+ * Copy data from "real" memory space to IO memory space.
+ */
+void memcpy_toio(volatile void __iomem *to, const void *from, size_t count)
+{
+	while (count && !IS_ALIGNED((unsigned long)to, 8)) {
+		__raw_writeb(*(u8 *)from, to);
+		from++;
+		to++;
+		count--;
+	}
+
+	while (count >= 8) {
+		__raw_writeq(*(u64 *)from, to);
+		from += 8;
+		to += 8;
+		count -= 8;
+	}
+
+	while (count) {
+		__raw_writeb(*(u8 *)from, to);
+		from++;
+		to++;
+		count--;
+	}
+}
+EXPORT_SYMBOL(memcpy_toio);
+
+/*
+ * "memset" on IO memory space.
+ */
+void memset_io(volatile void __iomem *dst, int c, size_t count)
+{
+	u64 qc = (u8)c;
+
+	qc |= qc << 8;
+	qc |= qc << 16;
+	qc |= qc << 32;
+
+	while (count && !IS_ALIGNED((unsigned long)dst, 8)) {
+		__raw_writeb(c, dst);
+		dst++;
+		count--;
+	}
+
+	while (count >= 8) {
+		__raw_writeq(qc, dst);
+		dst += 8;
+		count -= 8;
+	}
+
+	while (count) {
+		__raw_writeb(c, dst);
+		dst++;
+		count--;
+	}
+}
+EXPORT_SYMBOL(memset_io);
-- 
2.27.0


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