Adds sysfs interface as part of the of-fpga-region. This newly added sysfs interface uses Device Tree Overlay (DTO) files to configure/reprogram an FPGA while an operating system is running.This solution will not change the existing sequence When a DT overlay that targets an FPGA Region is applied. - Disable appropriate FPGA bridges. - Program the FPGA using the FPGA manager. - Enable the FPGA bridges. - The Device Tree overlay is accepted into the live tree. - Child devices are populated. When the overlay is removed, the child nodes will be removed, and the FPGA Region will disable the bridges. Usage: To configure/reprogram an FPGA region: echo "fpga.dtbo" > /sys/class/fpga_region/<region>/device/load To remove an FPGA region: echo "fpga.dtbo" > /sys/class/fpga_region/<region>/device/remove To get an FPGA region status: cat /sys/class/fpga_region/<region>/device/status Signed-off-by: Nava kishore Manne <nava.kishore.manne@xxxxxxx> --- .../ABI/testing/sysfs-class-of-fpga-region | 30 ++++++ MAINTAINERS | 1 + drivers/fpga/fpga-region.c | 4 +- drivers/fpga/of-fpga-region.c | 92 +++++++++++++++++++ include/linux/fpga/fpga-region.h | 15 +++ 5 files changed, 141 insertions(+), 1 deletion(-) create mode 100644 Documentation/ABI/testing/sysfs-class-of-fpga-region diff --git a/Documentation/ABI/testing/sysfs-class-of-fpga-region b/Documentation/ABI/testing/sysfs-class-of-fpga-region new file mode 100644 index 000000000000..aeb4e3be4ff3 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-class-of-fpga-region @@ -0,0 +1,30 @@ +What: /sys/class/fpga_region/<region>/device/load +Date: July 2024 +KernelVersion: 6.10 +Contact: Nava kishore Manne <nava.kishore.manne@xxxxxxx> +Description: (WO) Configure/Reprogram an FPGA region. + It uses Device Tree Overlay (DTO) files to configurer (or) + reprogram an FPGA. While an operating system is running. + The bitstream and the relevant DTO file has to be located + on the appropriate firmware path, typically, /lib/firmware. + For example, when user pass the option "echo fpga.dtbo" the + file /lib/firmware/fpga.dtbo must be present. + +What: /sys/class/fpga_region/<region>/device/remove +Date: July 2024 +KernelVersion: 6.10 +Contact: Nava kishore Manne <nava.kishore.manne@xxxxxxx> +Description: (WO) Revert the changes added by the load interface + It revert and free an overlay changeset added by the load + interface. + +What: /sys/class/fpga_region/<region>/device/status +Date: July 2024 +KernelVersion: 6.10 +Contact: Nava kishore Manne <nava.kishore.manne@xxxxxxx> +Description: (RO) Status of the FPGA region + This file is used to check the status of the FPGA region. + This is a list of strings for the supported status. + + * applied = FPGA is programmed and operating + * unapplied = Error while programing the FPGA diff --git a/MAINTAINERS b/MAINTAINERS index c0a3d9e93689..384f1d6f3af9 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -8795,6 +8795,7 @@ L: linux-fpga@xxxxxxxxxxxxxxx S: Maintained Q: http://patchwork.kernel.org/project/linux-fpga/list/ T: git git://git.kernel.org/pub/scm/linux/kernel/git/fpga/linux-fpga.git +F: Documentation/ABI/testing/sysfs-class-of-fpga-region F: Documentation/devicetree/bindings/fpga/ F: Documentation/driver-api/fpga/ F: Documentation/fpga/ diff --git a/drivers/fpga/fpga-region.c b/drivers/fpga/fpga-region.c index 753cd142503e..0733db1347ea 100644 --- a/drivers/fpga/fpga-region.c +++ b/drivers/fpga/fpga-region.c @@ -14,6 +14,7 @@ #include <linux/module.h> #include <linux/slab.h> #include <linux/spinlock.h> +#include <linux/of.h> static DEFINE_IDA(fpga_region_ida); static const struct class fpga_region_class; @@ -192,6 +193,7 @@ struct fpga_region * __fpga_region_register_full(struct device *parent, const struct fpga_region_info *info, struct module *owner) { + struct device_node *np = parent->of_node; struct fpga_region *region; int id, ret = 0; @@ -225,7 +227,7 @@ __fpga_region_register_full(struct device *parent, const struct fpga_region_info region->dev.of_node = parent->of_node; region->dev.id = id; - ret = dev_set_name(®ion->dev, "region%d", id); + ret = dev_set_name(®ion->dev, "%s", of_node_full_name(np)); if (ret) goto err_remove; diff --git a/drivers/fpga/of-fpga-region.c b/drivers/fpga/of-fpga-region.c index 8526a5a86f0c..edcc4c23a4b4 100644 --- a/drivers/fpga/of-fpga-region.c +++ b/drivers/fpga/of-fpga-region.c @@ -5,6 +5,7 @@ * Copyright (C) 2013-2016 Altera Corporation * Copyright (C) 2017 Intel Corporation */ +#include <linux/firmware.h> #include <linux/fpga/fpga-bridge.h> #include <linux/fpga/fpga-mgr.h> #include <linux/fpga/fpga-region.h> @@ -347,6 +348,7 @@ static int of_fpga_region_notify(struct notifier_block *nb, unsigned long action, void *arg) { struct of_overlay_notify_data *nd = arg; + struct fpga_overlay_image_info *ovcs; struct fpga_region *region; int ret; @@ -371,6 +373,10 @@ static int of_fpga_region_notify(struct notifier_block *nb, if (!region) return NOTIFY_OK; + ovcs = ®ion->ovcs; + if (!ovcs->fw) + return NOTIFY_STOP; + ret = 0; switch (action) { case OF_OVERLAY_PRE_APPLY: @@ -394,6 +400,91 @@ static struct notifier_block fpga_region_of_nb = { .notifier_call = of_fpga_region_notify, }; +static ssize_t load_store(struct device *dev, struct device_attribute *attr, + const char *buf, size_t count) +{ + struct fpga_region *region = to_fpga_region(dev); + struct fpga_overlay_image_info *ovcs = ®ion->ovcs; + char *s; + int err; + + /* if it's set do not allow changes */ + if (ovcs->ovcs_id) + return -EPERM; + + /* copy to path buffer (and make sure it's always zero terminated */ + count = snprintf(ovcs->path, sizeof(ovcs->path) - 1, "%s", buf); + ovcs->path[sizeof(ovcs->path) - 1] = '\0'; + + /* strip trailing newlines */ + s = ovcs->path + strlen(ovcs->path); + while (s > ovcs->path && *--s == '\n') + *s = '\0'; + + err = request_firmware(&ovcs->fw, ovcs->path, NULL); + if (err != 0) + goto out_err; + + err = of_overlay_fdt_apply((void *)ovcs->fw->data, ovcs->fw->size, + &ovcs->ovcs_id, NULL); + if (err < 0) { + pr_err("%s: Failed to create overlay (err=%d)\n", + __func__, err); + release_firmware(ovcs->fw); + goto out_err; + } + + return count; +out_err: + ovcs->path[0] = '\0'; + ovcs->ovcs_id = 0; + ovcs->fw = NULL; + + return err; +} + +static ssize_t remove_store(struct device *dev, struct device_attribute *attr, + const char *buf, size_t count) +{ + struct fpga_region *region = to_fpga_region(dev); + struct fpga_overlay_image_info *ovcs = ®ion->ovcs; + + if (!ovcs->ovcs_id) + return -EPERM; + + of_overlay_remove(&ovcs->ovcs_id); + release_firmware(ovcs->fw); + + ovcs->path[0] = '\0'; + ovcs->ovcs_id = 0; + ovcs->fw = NULL; + + return count; +} + +static ssize_t status_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct fpga_region *region = to_fpga_region(dev); + struct fpga_overlay_image_info *ovcs = ®ion->ovcs; + + return sprintf(buf, "%s\n", ovcs->ovcs_id > 0 ? + "applied" : "unapplied"); +} + +static DEVICE_ATTR_WO(load); +static DEVICE_ATTR_WO(remove); +static DEVICE_ATTR_RO(status); + +static struct attribute *of_fpga_region_attrs[] = { + &dev_attr_load.attr, + &dev_attr_remove.attr, + &dev_attr_status.attr, + NULL, +}; + +ATTRIBUTE_GROUPS(of_fpga_region); + static int of_fpga_region_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; @@ -440,6 +531,7 @@ static struct platform_driver of_fpga_region_driver = { .driver = { .name = "of-fpga-region", .of_match_table = of_match_ptr(fpga_region_of_match), + .dev_groups = of_fpga_region_groups, }, }; diff --git a/include/linux/fpga/fpga-region.h b/include/linux/fpga/fpga-region.h index 5fbc05fe70a6..36143301b49b 100644 --- a/include/linux/fpga/fpga-region.h +++ b/include/linux/fpga/fpga-region.h @@ -9,6 +9,19 @@ struct fpga_region; +/** + * struct fpga_overlay_image_info - information specific to an FPGA Overlay + * image. + * @fw: firmware of coeff table. + * @path: path of FPGA overlay image firmware file. + * @ovcs_id: overlay changeset id. + */ +struct fpga_overlay_image_info { + const struct firmware *fw; + char path[PATH_MAX]; + int ovcs_id; +}; + /** * struct fpga_region_info - collection of parameters an FPGA Region * @mgr: fpga region manager @@ -37,6 +50,7 @@ struct fpga_region_info { * @info: FPGA image info * @compat_id: FPGA region id for compatibility check. * @ops_owner: module containing the get_bridges function + * @ovcs: FPGA overlay image info * @priv: private data * @get_bridges: optional function to get bridges to a list */ @@ -48,6 +62,7 @@ struct fpga_region { struct fpga_image_info *info; struct fpga_compat_id *compat_id; struct module *ops_owner; + struct fpga_overlay_image_info ovcs; void *priv; int (*get_bridges)(struct fpga_region *region); }; -- 2.34.1
