From ebf877a51ad7b65e4ab024f021b60a4f7928864a Mon Sep 17 00:00:00 2001
From: Alan Tull <atull@kernel.org>
Date: Wed, 15 Nov 2017 14:20:13 -0600
Subject: fpga: mgr: separate getting/locking FPGA manager
Previously when the user gets a FPGA manager, it was locked
and nobody else could use it for programming.
This commit makes it straightforward to save a reference to an
FPGA manager and only lock it when programming the FPGA.
Add functions that get an FPGA manager's mutex for exclusive use:
* fpga_mgr_lock
* fpga_mgr_unlock
The following functions no longer lock an FPGA manager's mutex:
* of_fpga_mgr_get
* fpga_mgr_get
* fpga_mgr_put
Signed-off-by: Alan Tull <atull@kernel.org>
Acked-by: Moritz Fischer <mdf@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/fpga/fpga-mgr.c | 52 ++++++++++++++++++++++++++++++++++---------------
1 file changed, 36 insertions(+), 16 deletions(-)
(limited to 'drivers/fpga/fpga-mgr.c')
diff --git a/drivers/fpga/fpga-mgr.c b/drivers/fpga/fpga-mgr.c
index a8dd54945470..d27e8d2a149c 100644
--- a/drivers/fpga/fpga-mgr.c
+++ b/drivers/fpga/fpga-mgr.c
@@ -410,28 +410,19 @@ ATTRIBUTE_GROUPS(fpga_mgr);
static struct fpga_manager *__fpga_mgr_get(struct device *dev)
{
struct fpga_manager *mgr;
- int ret = -ENODEV;
mgr = to_fpga_manager(dev);
if (!mgr)
goto err_dev;
- /* Get exclusive use of fpga manager */
- if (!mutex_trylock(&mgr->ref_mutex)) {
- ret = -EBUSY;
- goto err_dev;
- }
-
if (!try_module_get(dev->parent->driver->owner))
- goto err_ll_mod;
+ goto err_dev;
return mgr;
-err_ll_mod:
- mutex_unlock(&mgr->ref_mutex);
err_dev:
put_device(dev);
- return ERR_PTR(ret);
+ return ERR_PTR(-ENODEV);
}
static int fpga_mgr_dev_match(struct device *dev, const void *data)
@@ -440,10 +431,10 @@ static int fpga_mgr_dev_match(struct device *dev, const void *data)
}
/**
- * fpga_mgr_get - get an exclusive reference to a fpga mgr
+ * fpga_mgr_get - get a reference to a fpga mgr
* @dev: parent device that fpga mgr was registered with
*
- * Given a device, get an exclusive reference to a fpga mgr.
+ * Given a device, get a reference to a fpga mgr.
*
* Return: fpga manager struct or IS_ERR() condition containing error code.
*/
@@ -464,10 +455,10 @@ static int fpga_mgr_of_node_match(struct device *dev, const void *data)
}
/**
- * of_fpga_mgr_get - get an exclusive reference to a fpga mgr
+ * of_fpga_mgr_get - get a reference to a fpga mgr
* @node: device node
*
- * Given a device node, get an exclusive reference to a fpga mgr.
+ * Given a device node, get a reference to a fpga mgr.
*
* Return: fpga manager struct or IS_ERR() condition containing error code.
*/
@@ -491,11 +482,40 @@ EXPORT_SYMBOL_GPL(of_fpga_mgr_get);
void fpga_mgr_put(struct fpga_manager *mgr)
{
module_put(mgr->dev.parent->driver->owner);
- mutex_unlock(&mgr->ref_mutex);
put_device(&mgr->dev);
}
EXPORT_SYMBOL_GPL(fpga_mgr_put);
+/**
+ * fpga_mgr_lock - Lock FPGA manager for exclusive use
+ * @mgr: fpga manager
+ *
+ * Given a pointer to FPGA Manager (from fpga_mgr_get() or
+ * of_fpga_mgr_put()) attempt to get the mutex.
+ *
+ * Return: 0 for success or -EBUSY
+ */
+int fpga_mgr_lock(struct fpga_manager *mgr)
+{
+ if (!mutex_trylock(&mgr->ref_mutex)) {
+ dev_err(&mgr->dev, "FPGA manager is in use.\n");
+ return -EBUSY;
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(fpga_mgr_lock);
+
+/**
+ * fpga_mgr_unlock - Unlock FPGA manager
+ * @mgr: fpga manager
+ */
+void fpga_mgr_unlock(struct fpga_manager *mgr)
+{
+ mutex_unlock(&mgr->ref_mutex);
+}
+EXPORT_SYMBOL_GPL(fpga_mgr_unlock);
+
/**
* fpga_mgr_register - register a low level fpga manager driver
* @dev: fpga manager device from pdev
--
cgit v1.2.3