arch/tile: introduce GXIO IORPC framework for tilegx

The GXIO I/O RPC subsystem handles exporting I/O hardware resources to
Linux and to applications running under Linux.

For instance, memory which is made available for I/O DMA must be mapped
by an I/O TLB; that means that such memory must be locked down by Linux,
so that it is not swapped or otherwise reused, as long as those I/O
TLB entries are active. Similarly, configuring direct hardware access
introduces new validation requirements. If a user application registers
memory, Linux must ensure that the supplied virtual addresses are valid,
and turn them into client physical addresses. Similarly, when Linux then
supplies those client physical addresses to the Tilera hypervisor, it
must in turn validate those before turning them into the real physical
addresses which are required by the hardware.

To the extent that these sorts of activities were required on previous
TILE architecture processors, they were implemented in a device-specific
fashion. This meant that every I/O device had its own Tilera hypervisor
driver, its own Linux driver, and in some cases its own user-level
library support. There was a large amount of more-or-less functionally
identical code in different places, particularly in the different Linux
drivers. For TILE-Gx, this support has been generalized into a common
framework, known as the I/O RPC framework or just IORPC.

The two "gxio" directories (one for headers, one for sources) start
with just a few files in each with this infrastructure commit, but
after adding support for the on-board I/O shims for networking, PCI,
USB, crypto, compression, I2CS, etc., there end up being about 20 files
in each directory.

More information on the IORPC framework is in the <hv/iorpc.h> header,
included in this commit.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>

1 files changed, 40 insertions, 0 deletions

diff --git a/arch/tile/include/gxio/common.h b/arch/tile/include/gxio/common.h
new file mode 100644
index 000000000000..724595a24d04
--- /dev/null
+++ b/arch/tile/include/gxio/common.h
@@ -0,0 +1,40 @@
+/*
+ * Copyright 2012 Tilera Corporation. All Rights Reserved.
+ *
+ *   This program is free software; you can redistribute it and/or
+ *   modify it under the terms of the GNU General Public License
+ *   as published by the Free Software Foundation, version 2.
+ *
+ *   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, GOOD TITLE or
+ *   NON INFRINGEMENT.  See the GNU General Public License for
+ *   more details.
+ */
+
+#ifndef _GXIO_COMMON_H_
+#define _GXIO_COMMON_H_
+
+/*
+ * Routines shared between the various GXIO device components.
+ */
+
+#include <hv/iorpc.h>
+
+#include <linux/types.h>
+#include <linux/compiler.h>
+#include <linux/io.h>
+
+/* Define the standard gxio MMIO functions using kernel functions. */
+#define __gxio_mmio_read8(addr)		readb(addr)
+#define __gxio_mmio_read16(addr)	readw(addr)
+#define __gxio_mmio_read32(addr)	readl(addr)
+#define __gxio_mmio_read64(addr)	readq(addr)
+#define __gxio_mmio_write8(addr, val)	writeb((val), (addr))
+#define __gxio_mmio_write16(addr, val)	writew((val), (addr))
+#define __gxio_mmio_write32(addr, val)	writel((val), (addr))
+#define __gxio_mmio_write64(addr, val)	writeq((val), (addr))
+#define __gxio_mmio_read(addr)		__gxio_mmio_read64(addr)
+#define __gxio_mmio_write(addr, val)	__gxio_mmio_write64((addr), (val))
+
+#endif /* !_GXIO_COMMON_H_ */