[PATCH v2 13/31] arm64: Device specific operations

This patch adds several definitions for device communication, including
I/O accessors and ioremap(). The __raw_* accessors are implemented as
inline asm to avoid compiler generation of post-indexed accesses (less
efficient to emulate in a virtualised environment).

Signed-off-by: Will Deacon <redacted>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
---
 arch/arm64/include/asm/device.h |   26 ++++
 arch/arm64/include/asm/fb.h     |   34 +++++
 arch/arm64/include/asm/io.h     |  263 +++++++++++++++++++++++++++++++++++++++
 arch/arm64/kernel/io.c          |   64 ++++++++++
 arch/arm64/mm/ioremap.c         |   84 +++++++++++++
 5 files changed, 471 insertions(+), 0 deletions(-)
 create mode 100644 arch/arm64/include/asm/device.h
 create mode 100644 arch/arm64/include/asm/fb.h
 create mode 100644 arch/arm64/include/asm/io.h
 create mode 100644 arch/arm64/kernel/io.c
 create mode 100644 arch/arm64/mm/ioremap.c

diff --git a/arch/arm64/include/asm/io.h b/arch/arm64/include/asm/io.h
new file mode 100644
index 0000000..48fa83f
--- /dev/null
+++ b/arch/arm64/include/asm/io.h

diff --git a/arch/arm64/kernel/io.c b/arch/arm64/kernel/io.c
new file mode 100644
index 0000000..7d37ead
--- /dev/null
+++ b/arch/arm64/kernel/io.c

@@ -0,0 +1,64 @@
+/*
+ * Based on arch/arm/kernel/io.c
+ *
+ * Copyright (C) 2012 ARM Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/export.h>
+#include <linux/types.h>
+#include <linux/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)
+{
+	unsigned char *t = to;
+	while (count) {
+		count--;
+		*t = readb(from);
+		t++;
+		from++;
+	}
+}
+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)
+{
+	const unsigned char *f = from;
+	while (count) {
+		count--;
+		writeb(*f, to);
+		f++;
+		to++;
+	}
+}
+EXPORT_SYMBOL(__memcpy_toio);
+
+/*
+ * "memset" on IO memory space.
+ */
+void __memset_io(volatile void __iomem *dst, int c, size_t count)
+{
+	while (count) {
+		count--;
+		writeb(c, dst);
+		dst++;
+	}
+}
+EXPORT_SYMBOL(__memset_io);