From ebf877a51ad7b65e4ab024f021b60a4f7928864a Mon Sep 17 00:00:00 2001 From: Alan Tull 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 Acked-by: Moritz Fischer Signed-off-by: Greg Kroah-Hartman --- 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