1 files changed, 318 insertions, 0 deletions
diff --git a/drivers/fpga/fpga-region.c b/drivers/fpga/fpga-region.c
new file mode 100644
index 0000000000..b364a92942
--- /dev/null
+++ b/drivers/fpga/fpga-region.c
@@ -0,0 +1,318 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * FPGA Region - Support for FPGA programming under Linux
+ *
+ *  Copyright (C) 2013-2016 Altera Corporation
+ *  Copyright (C) 2017 Intel Corporation
+ */
+#include <linux/fpga/fpga-bridge.h>
+#include <linux/fpga/fpga-mgr.h>
+#include <linux/fpga/fpga-region.h>
+#include <linux/idr.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+
+static DEFINE_IDA(fpga_region_ida);
+static const struct class fpga_region_class;
+
+struct fpga_region *
+fpga_region_class_find(struct device *start, const void *data,
+		       int (*match)(struct device *, const void *))
+{
+	struct device *dev;
+
+	dev = class_find_device(&fpga_region_class, start, data, match);
+	if (!dev)
+		return NULL;
+
+	return to_fpga_region(dev);
+}
+EXPORT_SYMBOL_GPL(fpga_region_class_find);
+
+/**
+ * fpga_region_get - get an exclusive reference to an fpga region
+ * @region: FPGA Region struct
+ *
+ * Caller should call fpga_region_put() when done with region.
+ *
+ * Return:
+ * * fpga_region struct if successful.
+ * * -EBUSY if someone already has a reference to the region.
+ * * -ENODEV if can't take parent driver module refcount.
+ */
+static struct fpga_region *fpga_region_get(struct fpga_region *region)
+{
+	struct device *dev = &region->dev;
+
+	if (!mutex_trylock(&region->mutex)) {
+		dev_dbg(dev, "%s: FPGA Region already in use\n", __func__);
+		return ERR_PTR(-EBUSY);
+	}
+
+	get_device(dev);
+	if (!try_module_get(dev->parent->driver->owner)) {
+		put_device(dev);
+		mutex_unlock(&region->mutex);
+		return ERR_PTR(-ENODEV);
+	}
+
+	dev_dbg(dev, "get\n");
+
+	return region;
+}
+
+/**
+ * fpga_region_put - release a reference to a region
+ *
+ * @region: FPGA region
+ */
+static void fpga_region_put(struct fpga_region *region)
+{
+	struct device *dev = &region->dev;
+
+	dev_dbg(dev, "put\n");
+
+	module_put(dev->parent->driver->owner);
+	put_device(dev);
+	mutex_unlock(&region->mutex);
+}
+
+/**
+ * fpga_region_program_fpga - program FPGA
+ *
+ * @region: FPGA region
+ *
+ * Program an FPGA using fpga image info (region->info).
+ * If the region has a get_bridges function, the exclusive reference for the
+ * bridges will be held if programming succeeds.  This is intended to prevent
+ * reprogramming the region until the caller considers it safe to do so.
+ * The caller will need to call fpga_bridges_put() before attempting to
+ * reprogram the region.
+ *
+ * Return: 0 for success or negative error code.
+ */
+int fpga_region_program_fpga(struct fpga_region *region)
+{
+	struct device *dev = &region->dev;
+	struct fpga_image_info *info = region->info;
+	int ret;
+
+	region = fpga_region_get(region);
+	if (IS_ERR(region)) {
+		dev_err(dev, "failed to get FPGA region\n");
+		return PTR_ERR(region);
+	}
+
+	ret = fpga_mgr_lock(region->mgr);
+	if (ret) {
+		dev_err(dev, "FPGA manager is busy\n");
+		goto err_put_region;
+	}
+
+	/*
+	 * In some cases, we already have a list of bridges in the
+	 * fpga region struct.  Or we don't have any bridges.
+	 */
+	if (region->get_bridges) {
+		ret = region->get_bridges(region);
+		if (ret) {
+			dev_err(dev, "failed to get fpga region bridges\n");
+			goto err_unlock_mgr;
+		}
+	}
+
+	ret = fpga_bridges_disable(&region->bridge_list);
+	if (ret) {
+		dev_err(dev, "failed to disable bridges\n");
+		goto err_put_br;
+	}
+
+	ret = fpga_mgr_load(region->mgr, info);
+	if (ret) {
+		dev_err(dev, "failed to load FPGA image\n");
+		goto err_put_br;
+	}
+
+	ret = fpga_bridges_enable(&region->bridge_list);
+	if (ret) {
+		dev_err(dev, "failed to enable region bridges\n");
+		goto err_put_br;
+	}
+
+	fpga_mgr_unlock(region->mgr);
+	fpga_region_put(region);
+
+	return 0;
+
+err_put_br:
+	if (region->get_bridges)
+		fpga_bridges_put(&region->bridge_list);
+err_unlock_mgr:
+	fpga_mgr_unlock(region->mgr);
+err_put_region:
+	fpga_region_put(region);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(fpga_region_program_fpga);
+
+static ssize_t compat_id_show(struct device *dev,
+			      struct device_attribute *attr, char *buf)
+{
+	struct fpga_region *region = to_fpga_region(dev);
+
+	if (!region->compat_id)
+		return -ENOENT;
+
+	return sprintf(buf, "%016llx%016llx\n",
+		       (unsigned long long)region->compat_id->id_h,
+		       (unsigned long long)region->compat_id->id_l);
+}
+
+static DEVICE_ATTR_RO(compat_id);
+
+static struct attribute *fpga_region_attrs[] = {
+	&dev_attr_compat_id.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(fpga_region);
+
+/**
+ * fpga_region_register_full - create and register an FPGA Region device
+ * @parent: device parent
+ * @info: parameters for FPGA Region
+ *
+ * Return: struct fpga_region or ERR_PTR()
+ */
+struct fpga_region *
+fpga_region_register_full(struct device *parent, const struct fpga_region_info *info)
+{
+	struct fpga_region *region;
+	int id, ret = 0;
+
+	if (!info) {
+		dev_err(parent,
+			"Attempt to register without required info structure\n");
+		return ERR_PTR(-EINVAL);
+	}
+
+	region = kzalloc(sizeof(*region), GFP_KERNEL);
+	if (!region)
+		return ERR_PTR(-ENOMEM);
+
+	id = ida_alloc(&fpga_region_ida, GFP_KERNEL);
+	if (id < 0) {
+		ret = id;
+		goto err_free;
+	}
+
+	region->mgr = info->mgr;
+	region->compat_id = info->compat_id;
+	region->priv = info->priv;
+	region->get_bridges = info->get_bridges;
+
+	mutex_init(&region->mutex);
+	INIT_LIST_HEAD(&region->bridge_list);
+
+	region->dev.class = &fpga_region_class;
+	region->dev.parent = parent;
+	region->dev.of_node = parent->of_node;
+	region->dev.id = id;
+
+	ret = dev_set_name(&region->dev, "region%d", id);
+	if (ret)
+		goto err_remove;
+
+	ret = device_register(&region->dev);
+	if (ret) {
+		put_device(&region->dev);
+		return ERR_PTR(ret);
+	}
+
+	return region;
+
+err_remove:
+	ida_free(&fpga_region_ida, id);
+err_free:
+	kfree(region);
+
+	return ERR_PTR(ret);
+}
+EXPORT_SYMBOL_GPL(fpga_region_register_full);
+
+/**
+ * fpga_region_register - create and register an FPGA Region device
+ * @parent: device parent
+ * @mgr: manager that programs this region
+ * @get_bridges: optional function to get bridges to a list
+ *
+ * This simple version of the register function should be sufficient for most users.
+ * The fpga_region_register_full() function is available for users that need to
+ * pass additional, optional parameters.
+ *
+ * Return: struct fpga_region or ERR_PTR()
+ */
+struct fpga_region *
+fpga_region_register(struct device *parent, struct fpga_manager *mgr,
+		     int (*get_bridges)(struct fpga_region *))
+{
+	struct fpga_region_info info = { 0 };
+
+	info.mgr = mgr;
+	info.get_bridges = get_bridges;
+
+	return fpga_region_register_full(parent, &info);
+}
+EXPORT_SYMBOL_GPL(fpga_region_register);
+
+/**
+ * fpga_region_unregister - unregister an FPGA region
+ * @region: FPGA region
+ *
+ * This function is intended for use in an FPGA region driver's remove function.
+ */
+void fpga_region_unregister(struct fpga_region *region)
+{
+	device_unregister(&region->dev);
+}
+EXPORT_SYMBOL_GPL(fpga_region_unregister);
+
+static void fpga_region_dev_release(struct device *dev)
+{
+	struct fpga_region *region = to_fpga_region(dev);
+
+	ida_free(&fpga_region_ida, region->dev.id);
+	kfree(region);
+}
+
+static const struct class fpga_region_class = {
+	.name = "fpga_region",
+	.dev_groups = fpga_region_groups,
+	.dev_release = fpga_region_dev_release,
+};
+
+/**
+ * fpga_region_init - creates the fpga_region class.
+ *
+ * Return: 0 on success or ERR_PTR() on error.
+ */
+static int __init fpga_region_init(void)
+{
+	return class_register(&fpga_region_class);
+}
+
+static void __exit fpga_region_exit(void)
+{
+	class_unregister(&fpga_region_class);
+	ida_destroy(&fpga_region_ida);
+}
+
+subsys_initcall(fpga_region_init);
+module_exit(fpga_region_exit);
+
+MODULE_DESCRIPTION("FPGA Region");
+MODULE_AUTHOR("Alan Tull <atull@kernel.org>");
+MODULE_LICENSE("GPL v2");