| From 2649550bc9bf2246dfe843874012c7cf621bdfca Mon Sep 17 00:00:00 2001 |
| From: Alan Tull <atull@opensource.altera.com> |
| Date: Tue, 1 Nov 2016 14:14:28 -0500 |
| Subject: [PATCH 030/103] fpga: add fpga bridge framework |
| |
| This framework adds API functions for enabling/ |
| disabling FPGA bridges under kernel control. |
| |
| This allows the Linux kernel to disable FPGA bridges |
| during FPGA reprogramming and to enable FPGA bridges |
| when FPGA reprogramming is done. This framework is |
| be manufacturer-agnostic, allowing it to be used in |
| interfaces that use the FPGA Manager Framework to |
| reprogram FPGA's. |
| |
| The functions are: |
| * of_fpga_bridge_get |
| * fpga_bridge_put |
| Get/put an exclusive reference to a FPGA bridge. |
| |
| * fpga_bridge_enable |
| * fpga_bridge_disable |
| Enable/Disable traffic through a bridge. |
| |
| * fpga_bridge_register |
| * fpga_bridge_unregister |
| Register/unregister a device-specific low level FPGA |
| Bridge driver. |
| |
| Get an exclusive reference to a bridge and add it to a list: |
| * fpga_bridge_get_to_list |
| |
| To enable/disable/put a set of bridges that are on a list: |
| * fpga_bridges_enable |
| * fpga_bridges_disable |
| * fpga_bridges_put |
| |
| Signed-off-by: Alan Tull <atull@opensource.altera.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| --- |
| drivers/fpga/Kconfig | 7 |
| drivers/fpga/Makefile | 3 |
| drivers/fpga/fpga-bridge.c | 395 +++++++++++++++++++++++++++++++++++++++ |
| include/linux/fpga/fpga-bridge.h | 60 +++++ |
| 4 files changed, 465 insertions(+) |
| create mode 100644 drivers/fpga/fpga-bridge.c |
| create mode 100644 include/linux/fpga/fpga-bridge.h |
| |
| --- a/drivers/fpga/Kconfig |
| +++ b/drivers/fpga/Kconfig |
| @@ -26,6 +26,13 @@ config FPGA_MGR_ZYNQ_FPGA |
| help |
| FPGA manager driver support for Xilinx Zynq FPGAs. |
| |
| +config FPGA_BRIDGE |
| + tristate "FPGA Bridge Framework" |
| + depends on OF |
| + help |
| + Say Y here if you want to support bridges connected between host |
| + processors and FPGAs or between FPGAs. |
| + |
| endif # FPGA |
| |
| endmenu |
| --- a/drivers/fpga/Makefile |
| +++ b/drivers/fpga/Makefile |
| @@ -8,3 +8,6 @@ obj-$(CONFIG_FPGA) += fpga-mgr.o |
| # FPGA Manager Drivers |
| obj-$(CONFIG_FPGA_MGR_SOCFPGA) += socfpga.o |
| obj-$(CONFIG_FPGA_MGR_ZYNQ_FPGA) += zynq-fpga.o |
| + |
| +# FPGA Bridge Drivers |
| +obj-$(CONFIG_FPGA_BRIDGE) += fpga-bridge.o |
| --- /dev/null |
| +++ b/drivers/fpga/fpga-bridge.c |
| @@ -0,0 +1,395 @@ |
| +/* |
| + * FPGA Bridge Framework Driver |
| + * |
| + * Copyright (C) 2013-2016 Altera Corporation, All Rights Reserved. |
| + * |
| + * This program is free software; you can redistribute it and/or modify it |
| + * under the terms and conditions of the GNU General Public License, |
| + * version 2, as published by the Free Software Foundation. |
| + * |
| + * This program is distributed in the hope 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/fpga/fpga-bridge.h> |
| +#include <linux/idr.h> |
| +#include <linux/kernel.h> |
| +#include <linux/module.h> |
| +#include <linux/of_platform.h> |
| +#include <linux/slab.h> |
| +#include <linux/spinlock.h> |
| + |
| +static DEFINE_IDA(fpga_bridge_ida); |
| +static struct class *fpga_bridge_class; |
| + |
| +/* Lock for adding/removing bridges to linked lists*/ |
| +spinlock_t bridge_list_lock; |
| + |
| +static int fpga_bridge_of_node_match(struct device *dev, const void *data) |
| +{ |
| + return dev->of_node == data; |
| +} |
| + |
| +/** |
| + * fpga_bridge_enable - Enable transactions on the bridge |
| + * |
| + * @bridge: FPGA bridge |
| + * |
| + * Return: 0 for success, error code otherwise. |
| + */ |
| +int fpga_bridge_enable(struct fpga_bridge *bridge) |
| +{ |
| + dev_dbg(&bridge->dev, "enable\n"); |
| + |
| + if (bridge->br_ops && bridge->br_ops->enable_set) |
| + return bridge->br_ops->enable_set(bridge, 1); |
| + |
| + return 0; |
| +} |
| +EXPORT_SYMBOL_GPL(fpga_bridge_enable); |
| + |
| +/** |
| + * fpga_bridge_disable - Disable transactions on the bridge |
| + * |
| + * @bridge: FPGA bridge |
| + * |
| + * Return: 0 for success, error code otherwise. |
| + */ |
| +int fpga_bridge_disable(struct fpga_bridge *bridge) |
| +{ |
| + dev_dbg(&bridge->dev, "disable\n"); |
| + |
| + if (bridge->br_ops && bridge->br_ops->enable_set) |
| + return bridge->br_ops->enable_set(bridge, 0); |
| + |
| + return 0; |
| +} |
| +EXPORT_SYMBOL_GPL(fpga_bridge_disable); |
| + |
| +/** |
| + * of_fpga_bridge_get - get an exclusive reference to a fpga bridge |
| + * |
| + * @np: node pointer of a FPGA bridge |
| + * @info: fpga image specific information |
| + * |
| + * Return fpga_bridge struct if successful. |
| + * Return -EBUSY if someone already has a reference to the bridge. |
| + * Return -ENODEV if @np is not a FPGA Bridge. |
| + */ |
| +struct fpga_bridge *of_fpga_bridge_get(struct device_node *np, |
| + struct fpga_image_info *info) |
| + |
| +{ |
| + struct device *dev; |
| + struct fpga_bridge *bridge; |
| + int ret = -ENODEV; |
| + |
| + dev = class_find_device(fpga_bridge_class, NULL, np, |
| + fpga_bridge_of_node_match); |
| + if (!dev) |
| + goto err_dev; |
| + |
| + bridge = to_fpga_bridge(dev); |
| + if (!bridge) |
| + goto err_dev; |
| + |
| + bridge->info = info; |
| + |
| + if (!mutex_trylock(&bridge->mutex)) { |
| + ret = -EBUSY; |
| + goto err_dev; |
| + } |
| + |
| + if (!try_module_get(dev->parent->driver->owner)) |
| + goto err_ll_mod; |
| + |
| + dev_dbg(&bridge->dev, "get\n"); |
| + |
| + return bridge; |
| + |
| +err_ll_mod: |
| + mutex_unlock(&bridge->mutex); |
| +err_dev: |
| + put_device(dev); |
| + return ERR_PTR(ret); |
| +} |
| +EXPORT_SYMBOL_GPL(of_fpga_bridge_get); |
| + |
| +/** |
| + * fpga_bridge_put - release a reference to a bridge |
| + * |
| + * @bridge: FPGA bridge |
| + */ |
| +void fpga_bridge_put(struct fpga_bridge *bridge) |
| +{ |
| + dev_dbg(&bridge->dev, "put\n"); |
| + |
| + bridge->info = NULL; |
| + module_put(bridge->dev.parent->driver->owner); |
| + mutex_unlock(&bridge->mutex); |
| + put_device(&bridge->dev); |
| +} |
| +EXPORT_SYMBOL_GPL(fpga_bridge_put); |
| + |
| +/** |
| + * fpga_bridges_enable - enable bridges in a list |
| + * @bridge_list: list of FPGA bridges |
| + * |
| + * Enable each bridge in the list. If list is empty, do nothing. |
| + * |
| + * Return 0 for success or empty bridge list; return error code otherwise. |
| + */ |
| +int fpga_bridges_enable(struct list_head *bridge_list) |
| +{ |
| + struct fpga_bridge *bridge; |
| + struct list_head *node; |
| + int ret; |
| + |
| + list_for_each(node, bridge_list) { |
| + bridge = list_entry(node, struct fpga_bridge, node); |
| + ret = fpga_bridge_enable(bridge); |
| + if (ret) |
| + return ret; |
| + } |
| + |
| + return 0; |
| +} |
| +EXPORT_SYMBOL_GPL(fpga_bridges_enable); |
| + |
| +/** |
| + * fpga_bridges_disable - disable bridges in a list |
| + * |
| + * @bridge_list: list of FPGA bridges |
| + * |
| + * Disable each bridge in the list. If list is empty, do nothing. |
| + * |
| + * Return 0 for success or empty bridge list; return error code otherwise. |
| + */ |
| +int fpga_bridges_disable(struct list_head *bridge_list) |
| +{ |
| + struct fpga_bridge *bridge; |
| + struct list_head *node; |
| + int ret; |
| + |
| + list_for_each(node, bridge_list) { |
| + bridge = list_entry(node, struct fpga_bridge, node); |
| + ret = fpga_bridge_disable(bridge); |
| + if (ret) |
| + return ret; |
| + } |
| + |
| + return 0; |
| +} |
| +EXPORT_SYMBOL_GPL(fpga_bridges_disable); |
| + |
| +/** |
| + * fpga_bridges_put - put bridges |
| + * |
| + * @bridge_list: list of FPGA bridges |
| + * |
| + * For each bridge in the list, put the bridge and remove it from the list. |
| + * If list is empty, do nothing. |
| + */ |
| +void fpga_bridges_put(struct list_head *bridge_list) |
| +{ |
| + struct fpga_bridge *bridge; |
| + struct list_head *node, *next; |
| + unsigned long flags; |
| + |
| + list_for_each_safe(node, next, bridge_list) { |
| + bridge = list_entry(node, struct fpga_bridge, node); |
| + |
| + fpga_bridge_put(bridge); |
| + |
| + spin_lock_irqsave(&bridge_list_lock, flags); |
| + list_del(&bridge->node); |
| + spin_unlock_irqrestore(&bridge_list_lock, flags); |
| + } |
| +} |
| +EXPORT_SYMBOL_GPL(fpga_bridges_put); |
| + |
| +/** |
| + * fpga_bridges_get_to_list - get a bridge, add it to a list |
| + * |
| + * @np: node pointer of a FPGA bridge |
| + * @info: fpga image specific information |
| + * @bridge_list: list of FPGA bridges |
| + * |
| + * Get an exclusive reference to the bridge and and it to the list. |
| + * |
| + * Return 0 for success, error code from of_fpga_bridge_get() othewise. |
| + */ |
| +int fpga_bridge_get_to_list(struct device_node *np, |
| + struct fpga_image_info *info, |
| + struct list_head *bridge_list) |
| +{ |
| + struct fpga_bridge *bridge; |
| + unsigned long flags; |
| + |
| + bridge = of_fpga_bridge_get(np, info); |
| + if (IS_ERR(bridge)) |
| + return PTR_ERR(bridge); |
| + |
| + spin_lock_irqsave(&bridge_list_lock, flags); |
| + list_add(&bridge->node, bridge_list); |
| + spin_unlock_irqrestore(&bridge_list_lock, flags); |
| + |
| + return 0; |
| +} |
| +EXPORT_SYMBOL_GPL(fpga_bridge_get_to_list); |
| + |
| +static ssize_t name_show(struct device *dev, |
| + struct device_attribute *attr, char *buf) |
| +{ |
| + struct fpga_bridge *bridge = to_fpga_bridge(dev); |
| + |
| + return sprintf(buf, "%s\n", bridge->name); |
| +} |
| + |
| +static ssize_t state_show(struct device *dev, |
| + struct device_attribute *attr, char *buf) |
| +{ |
| + struct fpga_bridge *bridge = to_fpga_bridge(dev); |
| + int enable = 1; |
| + |
| + if (bridge->br_ops && bridge->br_ops->enable_show) |
| + enable = bridge->br_ops->enable_show(bridge); |
| + |
| + return sprintf(buf, "%s\n", enable ? "enabled" : "disabled"); |
| +} |
| + |
| +static DEVICE_ATTR_RO(name); |
| +static DEVICE_ATTR_RO(state); |
| + |
| +static struct attribute *fpga_bridge_attrs[] = { |
| + &dev_attr_name.attr, |
| + &dev_attr_state.attr, |
| + NULL, |
| +}; |
| +ATTRIBUTE_GROUPS(fpga_bridge); |
| + |
| +/** |
| + * fpga_bridge_register - register a fpga bridge driver |
| + * @dev: FPGA bridge device from pdev |
| + * @name: FPGA bridge name |
| + * @br_ops: pointer to structure of fpga bridge ops |
| + * @priv: FPGA bridge private data |
| + * |
| + * Return: 0 for success, error code otherwise. |
| + */ |
| +int fpga_bridge_register(struct device *dev, const char *name, |
| + const struct fpga_bridge_ops *br_ops, void *priv) |
| +{ |
| + struct fpga_bridge *bridge; |
| + int id, ret = 0; |
| + |
| + if (!name || !strlen(name)) { |
| + dev_err(dev, "Attempt to register with no name!\n"); |
| + return -EINVAL; |
| + } |
| + |
| + bridge = kzalloc(sizeof(*bridge), GFP_KERNEL); |
| + if (!bridge) |
| + return -ENOMEM; |
| + |
| + id = ida_simple_get(&fpga_bridge_ida, 0, 0, GFP_KERNEL); |
| + if (id < 0) { |
| + ret = id; |
| + goto error_kfree; |
| + } |
| + |
| + mutex_init(&bridge->mutex); |
| + INIT_LIST_HEAD(&bridge->node); |
| + |
| + bridge->name = name; |
| + bridge->br_ops = br_ops; |
| + bridge->priv = priv; |
| + |
| + device_initialize(&bridge->dev); |
| + bridge->dev.class = fpga_bridge_class; |
| + bridge->dev.parent = dev; |
| + bridge->dev.of_node = dev->of_node; |
| + bridge->dev.id = id; |
| + dev_set_drvdata(dev, bridge); |
| + |
| + ret = dev_set_name(&bridge->dev, "br%d", id); |
| + if (ret) |
| + goto error_device; |
| + |
| + ret = device_add(&bridge->dev); |
| + if (ret) |
| + goto error_device; |
| + |
| + of_platform_populate(dev->of_node, NULL, NULL, dev); |
| + |
| + dev_info(bridge->dev.parent, "fpga bridge [%s] registered\n", |
| + bridge->name); |
| + |
| + return 0; |
| + |
| +error_device: |
| + ida_simple_remove(&fpga_bridge_ida, id); |
| +error_kfree: |
| + kfree(bridge); |
| + |
| + return ret; |
| +} |
| +EXPORT_SYMBOL_GPL(fpga_bridge_register); |
| + |
| +/** |
| + * fpga_bridge_unregister - unregister a fpga bridge driver |
| + * @dev: FPGA bridge device from pdev |
| + */ |
| +void fpga_bridge_unregister(struct device *dev) |
| +{ |
| + struct fpga_bridge *bridge = dev_get_drvdata(dev); |
| + |
| + /* |
| + * If the low level driver provides a method for putting bridge into |
| + * a desired state upon unregister, do it. |
| + */ |
| + if (bridge->br_ops && bridge->br_ops->fpga_bridge_remove) |
| + bridge->br_ops->fpga_bridge_remove(bridge); |
| + |
| + device_unregister(&bridge->dev); |
| +} |
| +EXPORT_SYMBOL_GPL(fpga_bridge_unregister); |
| + |
| +static void fpga_bridge_dev_release(struct device *dev) |
| +{ |
| + struct fpga_bridge *bridge = to_fpga_bridge(dev); |
| + |
| + ida_simple_remove(&fpga_bridge_ida, bridge->dev.id); |
| + kfree(bridge); |
| +} |
| + |
| +static int __init fpga_bridge_dev_init(void) |
| +{ |
| + spin_lock_init(&bridge_list_lock); |
| + |
| + fpga_bridge_class = class_create(THIS_MODULE, "fpga_bridge"); |
| + if (IS_ERR(fpga_bridge_class)) |
| + return PTR_ERR(fpga_bridge_class); |
| + |
| + fpga_bridge_class->dev_groups = fpga_bridge_groups; |
| + fpga_bridge_class->dev_release = fpga_bridge_dev_release; |
| + |
| + return 0; |
| +} |
| + |
| +static void __exit fpga_bridge_dev_exit(void) |
| +{ |
| + class_destroy(fpga_bridge_class); |
| + ida_destroy(&fpga_bridge_ida); |
| +} |
| + |
| +MODULE_DESCRIPTION("FPGA Bridge Driver"); |
| +MODULE_AUTHOR("Alan Tull <atull@opensource.altera.com>"); |
| +MODULE_LICENSE("GPL v2"); |
| + |
| +subsys_initcall(fpga_bridge_dev_init); |
| +module_exit(fpga_bridge_dev_exit); |
| --- /dev/null |
| +++ b/include/linux/fpga/fpga-bridge.h |
| @@ -0,0 +1,60 @@ |
| +#include <linux/device.h> |
| +#include <linux/fpga/fpga-mgr.h> |
| + |
| +#ifndef _LINUX_FPGA_BRIDGE_H |
| +#define _LINUX_FPGA_BRIDGE_H |
| + |
| +struct fpga_bridge; |
| + |
| +/** |
| + * struct fpga_bridge_ops - ops for low level FPGA bridge drivers |
| + * @enable_show: returns the FPGA bridge's status |
| + * @enable_set: set a FPGA bridge as enabled or disabled |
| + * @fpga_bridge_remove: set FPGA into a specific state during driver remove |
| + */ |
| +struct fpga_bridge_ops { |
| + int (*enable_show)(struct fpga_bridge *bridge); |
| + int (*enable_set)(struct fpga_bridge *bridge, bool enable); |
| + void (*fpga_bridge_remove)(struct fpga_bridge *bridge); |
| +}; |
| + |
| +/** |
| + * struct fpga_bridge - FPGA bridge structure |
| + * @name: name of low level FPGA bridge |
| + * @dev: FPGA bridge device |
| + * @mutex: enforces exclusive reference to bridge |
| + * @br_ops: pointer to struct of FPGA bridge ops |
| + * @info: fpga image specific information |
| + * @node: FPGA bridge list node |
| + * @priv: low level driver private date |
| + */ |
| +struct fpga_bridge { |
| + const char *name; |
| + struct device dev; |
| + struct mutex mutex; /* for exclusive reference to bridge */ |
| + const struct fpga_bridge_ops *br_ops; |
| + struct fpga_image_info *info; |
| + struct list_head node; |
| + void *priv; |
| +}; |
| + |
| +#define to_fpga_bridge(d) container_of(d, struct fpga_bridge, dev) |
| + |
| +struct fpga_bridge *of_fpga_bridge_get(struct device_node *node, |
| + struct fpga_image_info *info); |
| +void fpga_bridge_put(struct fpga_bridge *bridge); |
| +int fpga_bridge_enable(struct fpga_bridge *bridge); |
| +int fpga_bridge_disable(struct fpga_bridge *bridge); |
| + |
| +int fpga_bridges_enable(struct list_head *bridge_list); |
| +int fpga_bridges_disable(struct list_head *bridge_list); |
| +void fpga_bridges_put(struct list_head *bridge_list); |
| +int fpga_bridge_get_to_list(struct device_node *np, |
| + struct fpga_image_info *info, |
| + struct list_head *bridge_list); |
| + |
| +int fpga_bridge_register(struct device *dev, const char *name, |
| + const struct fpga_bridge_ops *br_ops, void *priv); |
| +void fpga_bridge_unregister(struct device *dev); |
| + |
| +#endif /* _LINUX_FPGA_BRIDGE_H */ |