[PATCH v5 08/28] fpga: dfl: add dfl_fpga_cdev_find_port

Wu Hao
2018-05-02T02:50:11Z

For feature devices, we need a method to find the port dedicated
to the device. This patch adds a function dfl_fpga_cdev_find_port
for this purpose. e.g FPGA Management Engine (FME) Partial
Reconfiguration sub feature, it uses this function to find
dedicated port on the device for PR function implementation.

Signed-off-by: Tim Whisonant <tim.whisonant@intel.com>
Signed-off-by: Enno Luebbers <enno.luebbers@intel.com>
Signed-off-by: Shiva Rao <shiva.rao@intel.com>
Signed-off-by: Christopher Rauer <christopher.rauer@intel.com>
Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: Wu Hao <hao.wu@intel.com>
Acked-by: Alan Tull <atull@kernel.org>
Acked-by: Moritz Fischer <mdf@kernel.org>
---
v3: s/fpga_for_each_port/fpga_cdev_find_port/
move fpga_cdev_find_port to fpga-dfl module.
v4: improve description in commit message.
add comments to remind user to put_device after use this function.
v5: add "dfl_" prefix to functions.
improve function comments per suggestion from Alan Tull.
add Acked-by from Alan and Moritz.
---
drivers/fpga/dfl.c | 32 ++++++++++++++++++++++++++++++++
drivers/fpga/dfl.h | 21 +++++++++++++++++++++
2 files changed, 53 insertions(+)

diff --git a/drivers/fpga/dfl.c b/drivers/fpga/dfl.c
index 18aba02..1e06efb 100644
--- a/drivers/fpga/dfl.c
+++ b/drivers/fpga/dfl.c
@@ -795,6 +795,38 @@ void dfl_fpga_remove_feature_devs(struct dfl_fpga_cdev *cdev)
}
EXPORT_SYMBOL_GPL(dfl_fpga_remove_feature_devs);

+/**
+ * __dfl_fpga_cdev_find_port - find a port under given container device
+ *
+ * @cdev: container device
+ * @data: data passed to match function
+ * @match: match function used to find specific port from the port device list
+ *
+ * Find a port device under container device. This function needs to be
+ * invoked with lock held.
+ *
+ * Return: pointer to port's platform device if successful, NULL otherwise.
+ *
+ * NOTE: you will need to drop the device reference with put_device() after use.
+ */
+struct platform_device *
+__dfl_fpga_cdev_find_port(struct dfl_fpga_cdev *cdev, void *data,
+ int (*match)(struct platform_device *, void *))
+{
+ struct dfl_feature_platform_data *pdata;
+ struct platform_device *port_dev;
+
+ list_for_each_entry(pdata, &cdev->port_dev_list, node) {
+ port_dev = pdata->dev;
+
+ if (match(port_dev, data) && get_device(&port_dev->dev))
+ return port_dev;
+ }
+
+ return NULL;
+}
+EXPORT_SYMBOL_GPL(__dfl_fpga_cdev_find_port);
+
static int __init dfl_fpga_init(void)
{
int ret;
diff --git a/drivers/fpga/dfl.h b/drivers/fpga/dfl.h
index 5fcb1a1..2b6aaef 100644
--- a/drivers/fpga/dfl.h
+++ b/drivers/fpga/dfl.h
@@ -290,4 +290,25 @@ struct dfl_fpga_cdev *
dfl_fpga_enumerate_feature_devs(struct dfl_fpga_enum_info *info);
void dfl_fpga_remove_feature_devs(struct dfl_fpga_cdev *cdev);

+/*
+ * need to drop the device reference with put_device() after use port platform
+ * device returned by __dfl_fpga_cdev_find_port and dfl_fpga_cdev_find_port
+ * functions.
+ */
+struct platform_device *
+__dfl_fpga_cdev_find_port(struct dfl_fpga_cdev *cdev, void *data,
+ int (*match)(struct platform_device *, void *));
+
+static inline struct platform_device *
+dfl_fpga_cdev_find_port(struct dfl_fpga_cdev *cdev, void *data,
+ int (*match)(struct platform_device *, void *))
+{
+ struct platform_device *pdev;
+
+ mutex_lock(&cdev->lock);
+ pdev = __dfl_fpga_cdev_find_port(cdev, data, match);
+ mutex_unlock(&cdev->lock);
+
+ return pdev;
+}
#endif /* __FPGA_DFL_H */
--
1.8.3.1