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-rw-r--r--drivers/fpga/of-fpga-region.c482
1 files changed, 482 insertions, 0 deletions
diff --git a/drivers/fpga/of-fpga-region.c b/drivers/fpga/of-fpga-region.c
new file mode 100644
index 000000000..ae82532fc
--- /dev/null
+++ b/drivers/fpga/of-fpga-region.c
@@ -0,0 +1,482 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * FPGA Region - Device Tree 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/of_platform.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+
+static const struct of_device_id fpga_region_of_match[] = {
+ { .compatible = "fpga-region", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, fpga_region_of_match);
+
+/**
+ * of_fpga_region_find - find FPGA region
+ * @np: device node of FPGA Region
+ *
+ * Caller will need to put_device(&region->dev) when done.
+ *
+ * Return: FPGA Region struct or NULL
+ */
+static struct fpga_region *of_fpga_region_find(struct device_node *np)
+{
+ return fpga_region_class_find(NULL, np, device_match_of_node);
+}
+
+/**
+ * of_fpga_region_get_mgr - get reference for FPGA manager
+ * @np: device node of FPGA region
+ *
+ * Get FPGA Manager from "fpga-mgr" property or from ancestor region.
+ *
+ * Caller should call fpga_mgr_put() when done with manager.
+ *
+ * Return: fpga manager struct or IS_ERR() condition containing error code.
+ */
+static struct fpga_manager *of_fpga_region_get_mgr(struct device_node *np)
+{
+ struct device_node *mgr_node;
+ struct fpga_manager *mgr;
+
+ of_node_get(np);
+ while (np) {
+ if (of_device_is_compatible(np, "fpga-region")) {
+ mgr_node = of_parse_phandle(np, "fpga-mgr", 0);
+ if (mgr_node) {
+ mgr = of_fpga_mgr_get(mgr_node);
+ of_node_put(mgr_node);
+ of_node_put(np);
+ return mgr;
+ }
+ }
+ np = of_get_next_parent(np);
+ }
+ of_node_put(np);
+
+ return ERR_PTR(-EINVAL);
+}
+
+/**
+ * of_fpga_region_get_bridges - create a list of bridges
+ * @region: FPGA region
+ *
+ * Create a list of bridges including the parent bridge and the bridges
+ * specified by "fpga-bridges" property. Note that the
+ * fpga_bridges_enable/disable/put functions are all fine with an empty list
+ * if that happens.
+ *
+ * Caller should call fpga_bridges_put(&region->bridge_list) when
+ * done with the bridges.
+ *
+ * Return: 0 for success (even if there are no bridges specified)
+ * or -EBUSY if any of the bridges are in use.
+ */
+static int of_fpga_region_get_bridges(struct fpga_region *region)
+{
+ struct device *dev = &region->dev;
+ struct device_node *region_np = dev->of_node;
+ struct fpga_image_info *info = region->info;
+ struct device_node *br, *np, *parent_br = NULL;
+ int i, ret;
+
+ /* If parent is a bridge, add to list */
+ ret = of_fpga_bridge_get_to_list(region_np->parent, info,
+ &region->bridge_list);
+
+ /* -EBUSY means parent is a bridge that is under use. Give up. */
+ if (ret == -EBUSY)
+ return ret;
+
+ /* Zero return code means parent was a bridge and was added to list. */
+ if (!ret)
+ parent_br = region_np->parent;
+
+ /* If overlay has a list of bridges, use it. */
+ br = of_parse_phandle(info->overlay, "fpga-bridges", 0);
+ if (br) {
+ of_node_put(br);
+ np = info->overlay;
+ } else {
+ np = region_np;
+ }
+
+ for (i = 0; ; i++) {
+ br = of_parse_phandle(np, "fpga-bridges", i);
+ if (!br)
+ break;
+
+ /* If parent bridge is in list, skip it. */
+ if (br == parent_br) {
+ of_node_put(br);
+ continue;
+ }
+
+ /* If node is a bridge, get it and add to list */
+ ret = of_fpga_bridge_get_to_list(br, info,
+ &region->bridge_list);
+ of_node_put(br);
+
+ /* If any of the bridges are in use, give up */
+ if (ret == -EBUSY) {
+ fpga_bridges_put(&region->bridge_list);
+ return -EBUSY;
+ }
+ }
+
+ return 0;
+}
+
+/**
+ * child_regions_with_firmware - Used to check the child region info.
+ * @overlay: device node of the overlay
+ *
+ * If the overlay adds child FPGA regions, they are not allowed to have
+ * firmware-name property.
+ *
+ * Return: 0 for OK or -EINVAL if child FPGA region adds firmware-name.
+ */
+static int child_regions_with_firmware(struct device_node *overlay)
+{
+ struct device_node *child_region;
+ const char *child_firmware_name;
+ int ret = 0;
+
+ of_node_get(overlay);
+
+ child_region = of_find_matching_node(overlay, fpga_region_of_match);
+ while (child_region) {
+ if (!of_property_read_string(child_region, "firmware-name",
+ &child_firmware_name)) {
+ ret = -EINVAL;
+ break;
+ }
+ child_region = of_find_matching_node(child_region,
+ fpga_region_of_match);
+ }
+
+ of_node_put(child_region);
+
+ if (ret)
+ pr_err("firmware-name not allowed in child FPGA region: %pOF",
+ child_region);
+
+ return ret;
+}
+
+/**
+ * of_fpga_region_parse_ov - parse and check overlay applied to region
+ *
+ * @region: FPGA region
+ * @overlay: overlay applied to the FPGA region
+ *
+ * Given an overlay applied to an FPGA region, parse the FPGA image specific
+ * info in the overlay and do some checking.
+ *
+ * Return:
+ * NULL if overlay doesn't direct us to program the FPGA.
+ * fpga_image_info struct if there is an image to program.
+ * error code for invalid overlay.
+ */
+static struct fpga_image_info *
+of_fpga_region_parse_ov(struct fpga_region *region,
+ struct device_node *overlay)
+{
+ struct device *dev = &region->dev;
+ struct fpga_image_info *info;
+ const char *firmware_name;
+ int ret;
+
+ if (region->info) {
+ dev_err(dev, "Region already has overlay applied.\n");
+ return ERR_PTR(-EINVAL);
+ }
+
+ /*
+ * Reject overlay if child FPGA Regions added in the overlay have
+ * firmware-name property (would mean that an FPGA region that has
+ * not been added to the live tree yet is doing FPGA programming).
+ */
+ ret = child_regions_with_firmware(overlay);
+ if (ret)
+ return ERR_PTR(ret);
+
+ info = fpga_image_info_alloc(dev);
+ if (!info)
+ return ERR_PTR(-ENOMEM);
+
+ info->overlay = overlay;
+
+ /* Read FPGA region properties from the overlay */
+ if (of_property_read_bool(overlay, "partial-fpga-config"))
+ info->flags |= FPGA_MGR_PARTIAL_RECONFIG;
+
+ if (of_property_read_bool(overlay, "external-fpga-config"))
+ info->flags |= FPGA_MGR_EXTERNAL_CONFIG;
+
+ if (of_property_read_bool(overlay, "encrypted-fpga-config"))
+ info->flags |= FPGA_MGR_ENCRYPTED_BITSTREAM;
+
+ if (!of_property_read_string(overlay, "firmware-name",
+ &firmware_name)) {
+ info->firmware_name = devm_kstrdup(dev, firmware_name,
+ GFP_KERNEL);
+ if (!info->firmware_name)
+ return ERR_PTR(-ENOMEM);
+ }
+
+ of_property_read_u32(overlay, "region-unfreeze-timeout-us",
+ &info->enable_timeout_us);
+
+ of_property_read_u32(overlay, "region-freeze-timeout-us",
+ &info->disable_timeout_us);
+
+ of_property_read_u32(overlay, "config-complete-timeout-us",
+ &info->config_complete_timeout_us);
+
+ /* If overlay is not programming the FPGA, don't need FPGA image info */
+ if (!info->firmware_name) {
+ ret = 0;
+ goto ret_no_info;
+ }
+
+ /*
+ * If overlay informs us FPGA was externally programmed, specifying
+ * firmware here would be ambiguous.
+ */
+ if (info->flags & FPGA_MGR_EXTERNAL_CONFIG) {
+ dev_err(dev, "error: specified firmware and external-fpga-config");
+ ret = -EINVAL;
+ goto ret_no_info;
+ }
+
+ return info;
+ret_no_info:
+ fpga_image_info_free(info);
+ return ERR_PTR(ret);
+}
+
+/**
+ * of_fpga_region_notify_pre_apply - pre-apply overlay notification
+ *
+ * @region: FPGA region that the overlay was applied to
+ * @nd: overlay notification data
+ *
+ * Called when an overlay targeted to an FPGA Region is about to be applied.
+ * Parses the overlay for properties that influence how the FPGA will be
+ * programmed and does some checking. If the checks pass, programs the FPGA.
+ * If the checks fail, overlay is rejected and does not get added to the
+ * live tree.
+ *
+ * Return: 0 for success or negative error code for failure.
+ */
+static int of_fpga_region_notify_pre_apply(struct fpga_region *region,
+ struct of_overlay_notify_data *nd)
+{
+ struct device *dev = &region->dev;
+ struct fpga_image_info *info;
+ int ret;
+
+ info = of_fpga_region_parse_ov(region, nd->overlay);
+ if (IS_ERR(info))
+ return PTR_ERR(info);
+
+ /* If overlay doesn't program the FPGA, accept it anyway. */
+ if (!info)
+ return 0;
+
+ if (region->info) {
+ dev_err(dev, "Region already has overlay applied.\n");
+ return -EINVAL;
+ }
+
+ region->info = info;
+ ret = fpga_region_program_fpga(region);
+ if (ret) {
+ /* error; reject overlay */
+ fpga_image_info_free(info);
+ region->info = NULL;
+ }
+
+ return ret;
+}
+
+/**
+ * of_fpga_region_notify_post_remove - post-remove overlay notification
+ *
+ * @region: FPGA region that was targeted by the overlay that was removed
+ * @nd: overlay notification data
+ *
+ * Called after an overlay has been removed if the overlay's target was a
+ * FPGA region.
+ */
+static void of_fpga_region_notify_post_remove(struct fpga_region *region,
+ struct of_overlay_notify_data *nd)
+{
+ fpga_bridges_disable(&region->bridge_list);
+ fpga_bridges_put(&region->bridge_list);
+ fpga_image_info_free(region->info);
+ region->info = NULL;
+}
+
+/**
+ * of_fpga_region_notify - reconfig notifier for dynamic DT changes
+ * @nb: notifier block
+ * @action: notifier action
+ * @arg: reconfig data
+ *
+ * This notifier handles programming an FPGA when a "firmware-name" property is
+ * added to an fpga-region.
+ *
+ * Return: NOTIFY_OK or error if FPGA programming fails.
+ */
+static int of_fpga_region_notify(struct notifier_block *nb,
+ unsigned long action, void *arg)
+{
+ struct of_overlay_notify_data *nd = arg;
+ struct fpga_region *region;
+ int ret;
+
+ switch (action) {
+ case OF_OVERLAY_PRE_APPLY:
+ pr_debug("%s OF_OVERLAY_PRE_APPLY\n", __func__);
+ break;
+ case OF_OVERLAY_POST_APPLY:
+ pr_debug("%s OF_OVERLAY_POST_APPLY\n", __func__);
+ return NOTIFY_OK; /* not for us */
+ case OF_OVERLAY_PRE_REMOVE:
+ pr_debug("%s OF_OVERLAY_PRE_REMOVE\n", __func__);
+ return NOTIFY_OK; /* not for us */
+ case OF_OVERLAY_POST_REMOVE:
+ pr_debug("%s OF_OVERLAY_POST_REMOVE\n", __func__);
+ break;
+ default: /* should not happen */
+ return NOTIFY_OK;
+ }
+
+ region = of_fpga_region_find(nd->target);
+ if (!region)
+ return NOTIFY_OK;
+
+ ret = 0;
+ switch (action) {
+ case OF_OVERLAY_PRE_APPLY:
+ ret = of_fpga_region_notify_pre_apply(region, nd);
+ break;
+
+ case OF_OVERLAY_POST_REMOVE:
+ of_fpga_region_notify_post_remove(region, nd);
+ break;
+ }
+
+ put_device(&region->dev);
+
+ if (ret)
+ return notifier_from_errno(ret);
+
+ return NOTIFY_OK;
+}
+
+static struct notifier_block fpga_region_of_nb = {
+ .notifier_call = of_fpga_region_notify,
+};
+
+static int of_fpga_region_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct device_node *np = dev->of_node;
+ struct fpga_region *region;
+ struct fpga_manager *mgr;
+ int ret;
+
+ /* Find the FPGA mgr specified by region or parent region. */
+ mgr = of_fpga_region_get_mgr(np);
+ if (IS_ERR(mgr))
+ return -EPROBE_DEFER;
+
+ region = fpga_region_register(dev, mgr, of_fpga_region_get_bridges);
+ if (IS_ERR(region)) {
+ ret = PTR_ERR(region);
+ goto eprobe_mgr_put;
+ }
+
+ of_platform_populate(np, fpga_region_of_match, NULL, &region->dev);
+ platform_set_drvdata(pdev, region);
+
+ dev_info(dev, "FPGA Region probed\n");
+
+ return 0;
+
+eprobe_mgr_put:
+ fpga_mgr_put(mgr);
+ return ret;
+}
+
+static int of_fpga_region_remove(struct platform_device *pdev)
+{
+ struct fpga_region *region = platform_get_drvdata(pdev);
+ struct fpga_manager *mgr = region->mgr;
+
+ fpga_region_unregister(region);
+ fpga_mgr_put(mgr);
+
+ return 0;
+}
+
+static struct platform_driver of_fpga_region_driver = {
+ .probe = of_fpga_region_probe,
+ .remove = of_fpga_region_remove,
+ .driver = {
+ .name = "of-fpga-region",
+ .of_match_table = of_match_ptr(fpga_region_of_match),
+ },
+};
+
+/**
+ * of_fpga_region_init - init function for fpga_region class
+ * Creates the fpga_region class and registers a reconfig notifier.
+ *
+ * Return: 0 on success, negative error code otherwise.
+ */
+static int __init of_fpga_region_init(void)
+{
+ int ret;
+
+ ret = of_overlay_notifier_register(&fpga_region_of_nb);
+ if (ret)
+ return ret;
+
+ ret = platform_driver_register(&of_fpga_region_driver);
+ if (ret)
+ goto err_plat;
+
+ return 0;
+
+err_plat:
+ of_overlay_notifier_unregister(&fpga_region_of_nb);
+ return ret;
+}
+
+static void __exit of_fpga_region_exit(void)
+{
+ platform_driver_unregister(&of_fpga_region_driver);
+ of_overlay_notifier_unregister(&fpga_region_of_nb);
+}
+
+subsys_initcall(of_fpga_region_init);
+module_exit(of_fpga_region_exit);
+
+MODULE_DESCRIPTION("FPGA Region");
+MODULE_AUTHOR("Alan Tull <atull@kernel.org>");
+MODULE_LICENSE("GPL v2");