rapidio: add mport char device driver

Add mport character device driver to provide user space interface to
basic RapidIO subsystem operations.

See included Documentation/rapidio/mport_cdev.txt for more details.

[akpm@linux-foundation.org: fix printk warning on i386]
[dan.carpenter@oracle.com: mport_cdev: fix some error codes]
Signed-off-by: Alexandre Bounine <alexandre.bounine@idt.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Tested-by: Barry Wood <barry.wood@idt.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Aurelien Jacquiot <a-jacquiot@ti.com>
Cc: Andre van Herk <andre.van.herk@prodrive-technologies.com>
Cc: Barry Wood <barry.wood@idt.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Documentation/rapidio/mport_cdev.txt

+RapidIO subsystem mport character device driver (rio_mport_cdev.c)
+==================================================================
+
+Version History:
+----------------
+  1.0.0 - Initial driver release.
+
+==================================================================
+
+I. Overview
+
+This device driver is the result of collaboration within the RapidIO.org
+Software Task Group (STG) between Texas Instruments, Freescale,
+Prodrive Technologies, Nokia Networks, BAE and IDT.  Additional input was
+received from other members of RapidIO.org. The objective was to create a
+character mode driver interface which exposes the capabilities of RapidIO
+devices directly to applications, in a manner that allows the numerous and
+varied RapidIO implementations to interoperate.
+
+This driver (MPORT_CDEV) provides access to basic RapidIO subsystem operations
+for user-space applications. Most of RapidIO operations are supported through
+'ioctl' system calls.
+
+When loaded this device driver creates filesystem nodes named rio_mportX in /dev
+directory for each registered RapidIO mport device. 'X' in the node name matches
+to unique port ID assigned to each local mport device.
+
+Using available set of ioctl commands user-space applications can perform
+following RapidIO bus and subsystem operations:
+
+- Reads and writes from/to configuration registers of mport devices
+    (RIO_MPORT_MAINT_READ_LOCAL/RIO_MPORT_MAINT_WRITE_LOCAL)
+- Reads and writes from/to configuration registers of remote RapidIO devices.
+  This operations are defined as RapidIO Maintenance reads/writes in RIO spec.
+    (RIO_MPORT_MAINT_READ_REMOTE/RIO_MPORT_MAINT_WRITE_REMOTE)
+- Set RapidIO Destination ID for mport devices (RIO_MPORT_MAINT_HDID_SET)
+- Set RapidIO Component Tag for mport devices (RIO_MPORT_MAINT_COMPTAG_SET)
+- Query logical index of mport devices (RIO_MPORT_MAINT_PORT_IDX_GET)
+- Query capabilities and RapidIO link configuration of mport devices
+    (RIO_MPORT_GET_PROPERTIES)
+- Enable/Disable reporting of RapidIO doorbell events to user-space applications
+    (RIO_ENABLE_DOORBELL_RANGE/RIO_DISABLE_DOORBELL_RANGE)
+- Enable/Disable reporting of RIO port-write events to user-space applications
+    (RIO_ENABLE_PORTWRITE_RANGE/RIO_DISABLE_PORTWRITE_RANGE)
+- Query/Control type of events reported through this driver: doorbells,
+  port-writes or both (RIO_SET_EVENT_MASK/RIO_GET_EVENT_MASK)
+- Configure/Map mport's outbound requests window(s) for specific size,
+  RapidIO destination ID, hopcount and request type
+    (RIO_MAP_OUTBOUND/RIO_UNMAP_OUTBOUND)
+- Configure/Map mport's inbound requests window(s) for specific size,
+  RapidIO base address and local memory base address
+    (RIO_MAP_INBOUND/RIO_UNMAP_INBOUND)
+- Allocate/Free contiguous DMA coherent memory buffer for DMA data transfers
+  to/from remote RapidIO devices (RIO_ALLOC_DMA/RIO_FREE_DMA)
+- Initiate DMA data transfers to/from remote RapidIO devices (RIO_TRANSFER).
+  Supports blocking, asynchronous and posted (a.k.a 'fire-and-forget') data
+  transfer modes.
+- Check/Wait for completion of asynchronous DMA data transfer
+    (RIO_WAIT_FOR_ASYNC)
+- Manage device objects supported by RapidIO subsystem (RIO_DEV_ADD/RIO_DEV_DEL).
+  This allows implementation of various RapidIO fabric enumeration algorithms
+  as user-space applications while using remaining functionality provided by
+  kernel RapidIO subsystem.
+
+II. Hardware Compatibility
+
+This device driver uses standard interfaces defined by kernel RapidIO subsystem
+and therefore it can be used with any mport device driver registered by RapidIO
+subsystem with limitations set by available mport implementation.
+
+At this moment the most common limitation is availability of RapidIO-specific
+DMA engine framework for specific mport device. Users should verify available
+functionality of their platform when planning to use this driver:
+
+- IDT Tsi721 PCIe-to-RapidIO bridge device and its mport device driver are fully
+  compatible with this driver.
+- Freescale SoCs 'fsl_rio' mport driver does not have implementation for RapidIO
+  specific DMA engine support and therefore DMA data transfers mport_cdev driver
+  are not available.
+
+III. Module parameters
+
+- 'dbg_level' - This parameter allows to control amount of debug information
+        generated by this device driver. This parameter is formed by set of
+        This parameter can be changed bit masks that correspond to the specific
+        functional block.
+        For mask definitions see 'drivers/rapidio/devices/rio_mport_cdev.c'
+        This parameter can be changed dynamically.
+        Use CONFIG_RAPIDIO_DEBUG=y to enable debug output at the top level.
+
+IV. Known problems
+
+  None.
+
+V. User-space Applications and API
+
+API library and applications that use this device driver are available from
+RapidIO.org.
+
+VI. TODO List
+
+- Add support for sending/receiving "raw" RapidIO messaging packets.
+- Add memory mapped DMA data transfers as an option when RapidIO-specific DMA
+  is not available.

drivers/rapidio/Kconfig

@@ -67,6 +67,14 @@ config RAPIDIO_ENUM_BASIC
 
 endchoice
 
+config RAPIDIO_MPORT_CDEV
+	tristate "RapidIO /dev mport device driver"
+	depends on RAPIDIO
+	help
+	  This option includes generic RapidIO mport device driver which
+	  allows to user space applications to perform RapidIO-specific
+	  operations through selected RapidIO mport.
+
 menu "RapidIO Switch drivers"
 	depends on RAPIDIO
 

drivers/rapidio/devices/Makefile

@@ -5,3 +5,4 @@
 obj-$(CONFIG_RAPIDIO_TSI721)	+= tsi721_mport.o
 tsi721_mport-y			:= tsi721.o
 tsi721_mport-$(CONFIG_RAPIDIO_DMA_ENGINE) += tsi721_dma.o
+obj-$(CONFIG_RAPIDIO_MPORT_CDEV) += rio_mport_cdev.o

include/linux/rio_mport_cdev.h

+/*
+ * Copyright (c) 2015-2016, Integrated Device Technology Inc.
+ * Copyright (c) 2015, Prodrive Technologies
+ * Copyright (c) 2015, Texas Instruments Incorporated
+ * Copyright (c) 2015, RapidIO Trade Association
+ * All rights reserved.
+ *
+ * This software is available to you under a choice of one of two licenses.
+ * You may choose to be licensed under the terms of the GNU General Public
+ * License(GPL) Version 2, or the BSD-3 Clause license below:
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ * this list of conditions and the following disclaimer in the documentation
+ * and/or other materials provided with the distribution.
+ *
+ * 3. Neither the name of the copyright holder nor the names of its contributors
+ * may be used to endorse or promote products derived from this software without
+ * specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
+ * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
+ * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+ * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
+ * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef _RIO_MPORT_CDEV_H_
+#define _RIO_MPORT_CDEV_H_
+
+#ifndef __user
+#define __user
+#endif
+
+struct rio_mport_maint_io {
+	uint32_t rioid;		/* destID of remote device */
+	uint32_t hopcount;	/* hopcount to remote device */
+	uint32_t offset;	/* offset in register space */
+	size_t length;		/* length in bytes */
+	void __user *buffer;	/* data buffer */
+};
+
+/*
+ * Definitions for RapidIO data transfers:
+ * - memory mapped (MAPPED)
+ * - packet generation from memory (TRANSFER)
+ */
+#define RIO_TRANSFER_MODE_MAPPED	(1 << 0)
+#define RIO_TRANSFER_MODE_TRANSFER	(1 << 1)
+#define RIO_CAP_DBL_SEND		(1 << 2)
+#define RIO_CAP_DBL_RECV		(1 << 3)
+#define RIO_CAP_PW_SEND			(1 << 4)
+#define RIO_CAP_PW_RECV			(1 << 5)
+#define RIO_CAP_MAP_OUTB		(1 << 6)
+#define RIO_CAP_MAP_INB			(1 << 7)
+
+struct rio_mport_properties {
+	uint16_t hdid;
+	uint8_t id;			/* Physical port ID */
+	uint8_t  index;
+	uint32_t flags;
+	uint32_t sys_size;		/* Default addressing size */
+	uint8_t  port_ok;
+	uint8_t  link_speed;
+	uint8_t  link_width;
+	uint32_t dma_max_sge;
+	uint32_t dma_max_size;
+	uint32_t dma_align;
+	uint32_t transfer_mode;		/* Default transfer mode */
+	uint32_t cap_sys_size;		/* Capable system sizes */
+	uint32_t cap_addr_size;		/* Capable addressing sizes */
+	uint32_t cap_transfer_mode;	/* Capable transfer modes */
+	uint32_t cap_mport;		/* Mport capabilities */
+};
+
+/*
+ * Definitions for RapidIO events;
+ * - incoming port-writes
+ * - incoming doorbells
+ */
+#define RIO_DOORBELL	(1 << 0)
+#define RIO_PORTWRITE	(1 << 1)
+
+struct rio_doorbell {
+	uint32_t rioid;
+	uint16_t payload;
+};
+
+struct rio_doorbell_filter {
+	uint32_t rioid;			/* 0xffffffff to match all ids */
+	uint16_t low;
+	uint16_t high;
+};
+
+
+struct rio_portwrite {
+	uint32_t payload[16];
+};
+
+struct rio_pw_filter {
+	uint32_t mask;
+	uint32_t low;
+	uint32_t high;
+};
+
+/* RapidIO base address for inbound requests set to value defined below
+ * indicates that no specific RIO-to-local address translation is requested
+ * and driver should use direct (one-to-one) address mapping.
+*/
+#define RIO_MAP_ANY_ADDR	(uint64_t)(~((uint64_t) 0))
+
+struct rio_mmap {
+	uint32_t rioid;
+	uint64_t rio_addr;
+	uint64_t length;
+	uint64_t handle;
+	void *address;
+};
+
+struct rio_dma_mem {
+	uint64_t length;		/* length of DMA memory */
+	uint64_t dma_handle;		/* handle associated with this memory */
+	void *buffer;			/* pointer to this memory */
+};
+
+
+struct rio_event {
+	unsigned int header;	/* event type RIO_DOORBELL or RIO_PORTWRITE */
+	union {
+		struct rio_doorbell doorbell;	/* header for RIO_DOORBELL */
+		struct rio_portwrite portwrite; /* header for RIO_PORTWRITE */
+	} u;
+};
+
+enum rio_transfer_sync {
+	RIO_TRANSFER_SYNC,	/* synchronous transfer */
+	RIO_TRANSFER_ASYNC,	/* asynchronous transfer */
+	RIO_TRANSFER_FAF,	/* fire-and-forget transfer */
+};
+
+enum rio_transfer_dir {
+	RIO_TRANSFER_DIR_READ,	/* Read operation */
+	RIO_TRANSFER_DIR_WRITE,	/* Write operation */
+};
+
+/*
+ * RapidIO data exchange transactions are lists of individual transfers. Each
+ * transfer exchanges data between two RapidIO devices by remote direct memory
+ * access and has its own completion code.
+ *
+ * The RapidIO specification defines four types of data exchange requests:
+ * NREAD, NWRITE, SWRITE and NWRITE_R. The RapidIO DMA channel interface allows
+ * to specify the required type of write operation or combination of them when
+ * only the last data packet requires response.
+ *
+ * NREAD:    read up to 256 bytes from remote device memory into local memory
+ * NWRITE:   write up to 256 bytes from local memory to remote device memory
+ *           without confirmation
+ * SWRITE:   as NWRITE, but all addresses and payloads must be 64-bit aligned
+ * NWRITE_R: as NWRITE, but expect acknowledgment from remote device.
+ *
+ * The default exchange is chosen from NREAD and any of the WRITE modes as the
+ * driver sees fit. For write requests the user can explicitly choose between
+ * any of the write modes for each transaction.
+ */
+enum rio_exchange {
+	RIO_EXCHANGE_DEFAULT,	/* Default method */
+	RIO_EXCHANGE_NWRITE,	/* All packets using NWRITE */
+	RIO_EXCHANGE_SWRITE,	/* All packets using SWRITE */
+	RIO_EXCHANGE_NWRITE_R,	/* Last packet NWRITE_R, others NWRITE */
+	RIO_EXCHANGE_SWRITE_R,	/* Last packet NWRITE_R, others SWRITE */
+	RIO_EXCHANGE_NWRITE_R_ALL, /* All packets using NWRITE_R */
+};
+
+struct rio_transfer_io {
+	uint32_t rioid;			/* Target destID */
+	uint64_t rio_addr;		/* Address in target's RIO mem space */
+	enum rio_exchange method;	/* Data exchange method */
+	void __user *loc_addr;
+	uint64_t handle;
+	uint64_t offset;		/* Offset in buffer */
+	uint64_t length;		/* Length in bytes */
+	uint32_t completion_code;	/* Completion code for this transfer */
+};
+
+struct rio_transaction {
+	uint32_t transfer_mode;		/* Data transfer mode */
+	enum rio_transfer_sync sync;	/* Synchronization method */
+	enum rio_transfer_dir dir;	/* Transfer direction */
+	size_t count;			/* Number of transfers */
+	struct rio_transfer_io __user *block;	/* Array of <count> transfers */
+};
+
+struct rio_async_tx_wait {
+	uint32_t token;		/* DMA transaction ID token */
+	uint32_t timeout;	/* Wait timeout in msec, if 0 use default TO */
+};
+
+#define RIO_MAX_DEVNAME_SZ	20
+
+struct rio_rdev_info {
+	uint32_t destid;
+	uint8_t hopcount;
+	uint32_t comptag;
+	char name[RIO_MAX_DEVNAME_SZ + 1];
+};
+
+/* Driver IOCTL codes */
+#define RIO_MPORT_DRV_MAGIC           'm'
+
+#define RIO_MPORT_MAINT_HDID_SET	\
+	_IOW(RIO_MPORT_DRV_MAGIC, 1, uint16_t)
+#define RIO_MPORT_MAINT_COMPTAG_SET	\
+	_IOW(RIO_MPORT_DRV_MAGIC, 2, uint32_t)
+#define RIO_MPORT_MAINT_PORT_IDX_GET	\
+	_IOR(RIO_MPORT_DRV_MAGIC, 3, uint32_t)
+#define RIO_MPORT_GET_PROPERTIES \
+	_IOR(RIO_MPORT_DRV_MAGIC, 4, struct rio_mport_properties)
+#define RIO_MPORT_MAINT_READ_LOCAL \
+	_IOR(RIO_MPORT_DRV_MAGIC, 5, struct rio_mport_maint_io)
+#define RIO_MPORT_MAINT_WRITE_LOCAL \
+	_IOW(RIO_MPORT_DRV_MAGIC, 6, struct rio_mport_maint_io)
+#define RIO_MPORT_MAINT_READ_REMOTE \
+	_IOR(RIO_MPORT_DRV_MAGIC, 7, struct rio_mport_maint_io)
+#define RIO_MPORT_MAINT_WRITE_REMOTE \
+	_IOW(RIO_MPORT_DRV_MAGIC, 8, struct rio_mport_maint_io)
+#define RIO_ENABLE_DOORBELL_RANGE	\
+	_IOW(RIO_MPORT_DRV_MAGIC, 9, struct rio_doorbell_filter)
+#define RIO_DISABLE_DOORBELL_RANGE	\
+	_IOW(RIO_MPORT_DRV_MAGIC, 10, struct rio_doorbell_filter)
+#define RIO_ENABLE_PORTWRITE_RANGE	\
+	_IOW(RIO_MPORT_DRV_MAGIC, 11, struct rio_pw_filter)
+#define RIO_DISABLE_PORTWRITE_RANGE	\
+	_IOW(RIO_MPORT_DRV_MAGIC, 12, struct rio_pw_filter)
+#define RIO_SET_EVENT_MASK		\
+	_IOW(RIO_MPORT_DRV_MAGIC, 13, unsigned int)
+#define RIO_GET_EVENT_MASK		\
+	_IOR(RIO_MPORT_DRV_MAGIC, 14, unsigned int)
+#define RIO_MAP_OUTBOUND \
+	_IOWR(RIO_MPORT_DRV_MAGIC, 15, struct rio_mmap)
+#define RIO_UNMAP_OUTBOUND \
+	_IOW(RIO_MPORT_DRV_MAGIC, 16, struct rio_mmap)
+#define RIO_MAP_INBOUND \
+	_IOWR(RIO_MPORT_DRV_MAGIC, 17, struct rio_mmap)
+#define RIO_UNMAP_INBOUND \
+	_IOW(RIO_MPORT_DRV_MAGIC, 18, uint64_t)
+#define RIO_ALLOC_DMA \
+	_IOWR(RIO_MPORT_DRV_MAGIC, 19, struct rio_dma_mem)
+#define RIO_FREE_DMA \
+	_IOW(RIO_MPORT_DRV_MAGIC, 20, uint64_t)
+#define RIO_TRANSFER \
+	_IOWR(RIO_MPORT_DRV_MAGIC, 21, struct rio_transaction)
+#define RIO_WAIT_FOR_ASYNC \
+	_IOW(RIO_MPORT_DRV_MAGIC, 22, struct rio_async_tx_wait)
+#define RIO_DEV_ADD \
+	_IOW(RIO_MPORT_DRV_MAGIC, 23, struct rio_rdev_info)
+#define RIO_DEV_DEL \
+	_IOW(RIO_MPORT_DRV_MAGIC, 24, struct rio_rdev_info)
+
+#endif /* _RIO_MPORT_CDEV_H_ */

include/uapi/linux/Kbuild

@@ -354,6 +354,7 @@ header-y += reiserfs_fs.h
 header-y += reiserfs_xattr.h
 header-y += resource.h
 header-y += rfkill.h
+header-y += rio_mport_cdev.h
 header-y += romfs_fs.h
 header-y += rose.h
 header-y += route.h