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 <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Tony Lindgren <tony@atomide.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Olof Johansson <olof@lixom.net>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
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);