Hi Alan,
comments inline. While I see how this is useful, I have the
suspicion that from the moment this gets merged vendor kernels
will just default to use this ...
On Wed, Aug 15, 2018 at 05:09:58PM -0500, Alan Tull wrote:
> From: Alan Tull <atull@xxxxxxxxxxxxxxxxxxxxx>
>
> Implement DebugFS for the FPGA Manager Framework for
> debugging and developmental use.
>
> Enabled by CONFIG_FPGA_MGR_DEBUG_FS
>
> Each FPGA gets its own directory such as
> <debugfs>/fpga_manager/fpga0 and three files:
>
> * [RW] flags = flags as defined in fpga-mgr.h
> * [RW] firmware_name = write/read back name of FPGA image
> firmware file to program
> * [WO] image = write-only file for directly writing
> fpga image w/o firmware layer
> * [RW] config_complete_timeout_us = maximum for the FPGA to
> go to the operating state after
> programming
>
> The debugfs is implemented in a separate fpga_mgr_debugfs.c
> file, but the FPGA manager core is still built as one
> module. Note the name change from fpga-mgr.ko to fpga_mgr.ko.
>
> Signed-off-by: Alan Tull <atull@xxxxxxxxxx>
> Signed-off-by: Matthew Gerlach <matthew.gerlach@xxxxxxxxxxxxxxx>
> ---
> drivers/fpga/Kconfig | 7 ++
> drivers/fpga/Makefile | 4 +-
> drivers/fpga/fpga-mgr-debugfs.c | 221 ++++++++++++++++++++++++++++++++++++++++
> drivers/fpga/fpga-mgr-debugfs.h | 22 ++++
> drivers/fpga/fpga-mgr.c | 8 ++
> include/linux/fpga/fpga-mgr.h | 3 +
> 6 files changed, 264 insertions(+), 1 deletion(-)
> create mode 100644 drivers/fpga/fpga-mgr-debugfs.c
> create mode 100644 drivers/fpga/fpga-mgr-debugfs.h
>
> diff --git a/drivers/fpga/Kconfig b/drivers/fpga/Kconfig
> index 1ebcef4..600924d 100644
> --- a/drivers/fpga/Kconfig
> +++ b/drivers/fpga/Kconfig
> @@ -9,6 +9,13 @@ menuconfig FPGA
> kernel. The FPGA framework adds a FPGA manager class and FPGA
> manager drivers.
>
> +config FPGA_MGR_DEBUG_FS
> + bool "FPGA Manager DebugFS"
> + depends on FPGA && DEBUG_FS
> + help
> + Say Y here if you want to expose a DebugFS interface for the
> + FPGA Manager Framework.
> +
> if FPGA
>
> config FPGA_MGR_SOCFPGA
> diff --git a/drivers/fpga/Makefile b/drivers/fpga/Makefile
> index 7a2d73b..62910cc 100644
> --- a/drivers/fpga/Makefile
> +++ b/drivers/fpga/Makefile
> @@ -4,7 +4,9 @@
> #
>
> # Core FPGA Manager Framework
> -obj-$(CONFIG_FPGA) += fpga-mgr.o
> +obj-$(CONFIG_FPGA) += fpga_mgr.o
> +fpga_mgr-y := fpga-mgr.o
> +fpga_mgr-$(CONFIG_FPGA_MGR_DEBUG_FS) += fpga-mgr-debugfs.o
>
> # FPGA Manager Drivers
> obj-$(CONFIG_FPGA_MGR_ALTERA_CVP) += altera-cvp.o
> diff --git a/drivers/fpga/fpga-mgr-debugfs.c b/drivers/fpga/fpga-mgr-debugfs.c
> new file mode 100644
> index 0000000..f2fdf58
> --- /dev/null
> +++ b/drivers/fpga/fpga-mgr-debugfs.c
> @@ -0,0 +1,221 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * FPGA Manager DebugFS
> + *
> + * Copyright (C) 2016-2018 Intel Corporation. All rights reserved.
> + */
> +#include <linux/debugfs.h>
> +#include <linux/fpga/fpga-mgr.h>
> +#include <linux/slab.h>
> +#include <linux/uaccess.h>
> +
> +static struct dentry *fpga_mgr_debugfs_root;
> +
> +struct fpga_mgr_debugfs {
> + struct dentry *debugfs_dir;
> + struct fpga_image_info *info;
> +};
> +
> +static ssize_t fpga_mgr_firmware_write_file(struct file *file,
> + const char __user *user_buf,
> + size_t count, loff_t *ppos)
> +{
> + struct fpga_manager *mgr = file->private_data;
> + struct fpga_mgr_debugfs *debugfs = mgr->debugfs;
> + struct device *dev = &mgr->dev;
> + char *buf;
> + int ret;
> +
> + ret = fpga_mgr_lock(mgr);
> + if (ret) {
> + dev_err(dev, "FPGA manager is busy\n");
> + return -EBUSY;
> + }
> +
> + buf = devm_kzalloc(dev, count, GFP_KERNEL);
> + if (!buf) {
> + fpga_mgr_unlock(mgr);
> + return -ENOMEM;
> + }
> +
> + if (copy_from_user(buf, user_buf, count)) {
> + fpga_mgr_unlock(mgr);
> + devm_kfree(dev, buf);
> + return -EFAULT;
> + }
> +
> + buf[count] = 0;
> + if (buf[count - 1] == '\n')
> + buf[count - 1] = 0;
> +
> + /* Release previous firmware name (if any). Save current one. */
> + if (debugfs->info->firmware_name)
> + devm_kfree(dev, debugfs->info->firmware_name);
> + debugfs->info->firmware_name = buf;
> +
> + ret = fpga_mgr_load(mgr, debugfs->info);
> + if (ret)
> + dev_err(dev, "fpga_mgr_load returned with value %d\n", ret);
> +
> + fpga_mgr_unlock(mgr);
> +
> + return count;
> +}
> +
> +static ssize_t fpga_mgr_firmware_read_file(struct file *file,
> + char __user *user_buf,
> + size_t count, loff_t *ppos)
> +{
> + struct fpga_manager *mgr = file->private_data;
> + struct fpga_mgr_debugfs *debugfs = mgr->debugfs;
> + char *buf;
> + int ret;
> +
> + if (!debugfs->info->firmware_name)
> + return 0;
> +
> + buf = kzalloc(PAGE_SIZE, GFP_KERNEL);
> + if (!buf)
> + return -ENOMEM;
> +
> + ret = snprintf(buf, PAGE_SIZE, "%s\n", debugfs->info->firmware_name);
snip:
---->8->8->8-----
> + if (ret < 0) {
> + kfree(buf);
> + return ret;
> + }
---->8->8->8-----
just replace with:
if (ret < 0)
goto out;
> +
> + ret = simple_read_from_buffer(user_buf, count, ppos, buf, ret);
out:
> + kfree(buf);
> + return ret;
> +}
> +
> +static const struct file_operations fpga_mgr_firmware_fops = {
> + .open = simple_open,
> + .read = fpga_mgr_firmware_read_file,
> + .write = fpga_mgr_firmware_write_file,
> + .llseek = default_llseek,
> +};
> +
> +static ssize_t fpga_mgr_image_write_file(struct file *file,
> + const char __user *user_buf,
> + size_t count, loff_t *ppos)
> +{
> + struct fpga_manager *mgr = file->private_data;
> + struct fpga_mgr_debugfs *debugfs = mgr->debugfs;
> + struct device *dev = &mgr->dev;
> + char *buf;
> + int ret;
> +
> + dev_info(dev, "writing %zu bytes to %s\n", count, mgr->name);
> +
> + ret = fpga_mgr_lock(mgr);
> + if (ret) {
> + dev_err(dev, "FPGA manager is busy\n");
> + return -EBUSY;
> + }
> +
> + buf = kzalloc(count, GFP_KERNEL);
> + if (!buf) {
> + fpga_mgr_unlock(mgr);
> + return -ENOMEM;
> + }
> +
> + if (copy_from_user(buf, user_buf, count)) {
> + fpga_mgr_unlock(mgr);
> + kfree(buf);
> + return -EFAULT;
> + }
> +
> + /* If firmware interface was previously used, forget it. */
> + if (debugfs->info->firmware_name)
> + devm_kfree(dev, debugfs->info->firmware_name);
> + debugfs->info->firmware_name = NULL;
> +
> + debugfs->info->buf = buf;
> + debugfs->info->count = count;
> +
> + ret = fpga_mgr_load(mgr, debugfs->info);
> + if (ret)
> + dev_err(dev, "fpga_mgr_load returned with value %d\n", ret);
> +
> + fpga_mgr_unlock(mgr);
> +
> + debugfs->info->buf = NULL;
> + debugfs->info->count = 0;
Is that ordering between unlock() and setting those correct?
> +
> + kfree(buf);
> +
> + return count;
> +}
> +
> +static const struct file_operations fpga_mgr_image_fops = {
> + .open = simple_open,
> + .write = fpga_mgr_image_write_file,
> + .llseek = default_llseek,
> +};
> +
> +void fpga_mgr_debugfs_add(struct fpga_manager *mgr)
> +{
> + struct device *dev = &mgr->dev;
> + struct fpga_mgr_debugfs *debugfs;
> + struct fpga_image_info *info;
> +
> + if (!fpga_mgr_debugfs_root)
> + return;
> +
> + debugfs = kzalloc(sizeof(*debugfs), GFP_KERNEL);
> + if (!debugfs)
> + return;
> +
> + info = fpga_image_info_alloc(dev);
> + if (!info) {
> + kfree(debugfs);
> + return;
> + }
> + debugfs->info = info;
> +
> + debugfs->debugfs_dir = debugfs_create_dir(dev_name(dev),
> + fpga_mgr_debugfs_root);
> +
> + debugfs_create_file("firmware_name", 0600, debugfs->debugfs_dir, mgr,
> + &fpga_mgr_firmware_fops);
> +
> + debugfs_create_file("image", 0200, debugfs->debugfs_dir, mgr,
> + &fpga_mgr_image_fops);
> +
> + debugfs_create_u32("flags", 0600, debugfs->debugfs_dir, &info->flags);
> +
> + debugfs_create_u32("config_complete_timeout_us", 0600,
> + debugfs->debugfs_dir,
> + &info->config_complete_timeout_us);
> +
> + mgr->debugfs = debugfs;
> +}
> +
> +void fpga_mgr_debugfs_remove(struct fpga_manager *mgr)
> +{
> + struct fpga_mgr_debugfs *debugfs = mgr->debugfs;
> +
> + if (!fpga_mgr_debugfs_root)
> + return;
> +
> + debugfs_remove_recursive(debugfs->debugfs_dir);
> +
> + /* this function also frees debugfs->info->firmware_name */
> + fpga_image_info_free(debugfs->info);
> +
> + kfree(debugfs);
> +}
> +
> +void fpga_mgr_debugfs_init(void)
> +{
> + fpga_mgr_debugfs_root = debugfs_create_dir("fpga_manager", NULL);
> + if (!fpga_mgr_debugfs_root)
> + pr_warn("fpga_mgr: Failed to create debugfs root\n");
> +}
> +
> +void fpga_mgr_debugfs_uninit(void)
> +{
> + debugfs_remove_recursive(fpga_mgr_debugfs_root);
> +}
> diff --git a/drivers/fpga/fpga-mgr-debugfs.h b/drivers/fpga/fpga-mgr-debugfs.h
> new file mode 100644
> index 0000000..17cd3eb
> --- /dev/null
> +++ b/drivers/fpga/fpga-mgr-debugfs.h
> @@ -0,0 +1,22 @@
> +// SPDX-License-Identifier: GPL-2.0
> +
> +#ifndef _LINUX_FPGA_MGR_DEBUGFS_H
> +#define _LINUX_FPGA_MGR_DEBUGFS_H
> +
> +#if IS_ENABLED(CONFIG_FPGA_MGR_DEBUG_FS)
> +
> +void fpga_mgr_debugfs_add(struct fpga_manager *mgr);
> +void fpga_mgr_debugfs_remove(struct fpga_manager *mgr);
> +void fpga_mgr_debugfs_init(void);
> +void fpga_mgr_debugfs_uninit(void);
> +
> +#else
> +
> +void fpga_mgr_debugfs_add(struct fpga_manager *mgr) {}
> +void fpga_mgr_debugfs_remove(struct fpga_manager *mgr) {}
> +void fpga_mgr_debugfs_init(void) {}
> +void fpga_mgr_debugfs_uninit(void) {}
> +
> +#endif /* CONFIG_FPGA_MGR_DEBUG_FS */
> +
> +#endif /*_LINUX_FPGA_MGR_DEBUGFS_H */
> diff --git a/drivers/fpga/fpga-mgr.c b/drivers/fpga/fpga-mgr.c
> index c8684bc..66eb6f6 100644
> --- a/drivers/fpga/fpga-mgr.c
> +++ b/drivers/fpga/fpga-mgr.c
> @@ -17,6 +17,7 @@
> #include <linux/slab.h>
> #include <linux/scatterlist.h>
> #include <linux/highmem.h>
> +#include "fpga-mgr-debugfs.h"
>
> static DEFINE_IDA(fpga_mgr_ida);
> static struct class *fpga_mgr_class;
> @@ -698,6 +699,8 @@ int fpga_mgr_register(struct fpga_manager *mgr)
> if (ret)
> goto error_device;
>
> + fpga_mgr_debugfs_add(mgr);
> +
> dev_info(&mgr->dev, "%s registered\n", mgr->name);
>
> return 0;
> @@ -722,6 +725,8 @@ void fpga_mgr_unregister(struct fpga_manager *mgr)
> {
> dev_info(&mgr->dev, "%s %s\n", __func__, mgr->name);
>
> + fpga_mgr_debugfs_remove(mgr);
> +
> /*
> * If the low level driver provides a method for putting fpga into
> * a desired state upon unregister, do it.
> @@ -748,11 +753,14 @@ static int __init fpga_mgr_class_init(void)
> fpga_mgr_class->dev_groups = fpga_mgr_groups;
> fpga_mgr_class->dev_release = fpga_mgr_dev_release;
>
> + fpga_mgr_debugfs_init();
> +
> return 0;
> }
>
> static void __exit fpga_mgr_class_exit(void)
> {
> + fpga_mgr_debugfs_uninit();
> class_destroy(fpga_mgr_class);
> ida_destroy(&fpga_mgr_ida);
> }
> diff --git a/include/linux/fpga/fpga-mgr.h b/include/linux/fpga/fpga-mgr.h
> index 777c502..e8f2159 100644
> --- a/include/linux/fpga/fpga-mgr.h
> +++ b/include/linux/fpga/fpga-mgr.h
> @@ -170,6 +170,9 @@ struct fpga_manager {
> struct fpga_compat_id *compat_id;
> const struct fpga_manager_ops *mops;
> void *priv;
> +#if IS_ENABLED(CONFIG_FPGA_MGR_DEBUG_FS)
> + void *debugfs;
> +#endif
> };
>
> #define to_fpga_manager(d) container_of(d, struct fpga_manager, dev)
> --
> 2.7.4
>
Thanks,
Moritz
