diff options
author | Alan Tull <atull@kernel.org> | 2017-11-15 14:20:13 -0600 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-11-28 16:30:37 +0100 |
commit | ebf877a51ad7b65e4ab024f021b60a4f7928864a (patch) | |
tree | cca7dfc760c45f32bdbd9e6f69106dd24651d468 /drivers/fpga | |
parent | 5cf0c7f6502f26332b46fa87914553a4d6ae75ac (diff) | |
download | linux-ebf877a51ad7b65e4ab024f021b60a4f7928864a.tar.bz2 |
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>
Diffstat (limited to 'drivers/fpga')
-rw-r--r-- | drivers/fpga/fpga-mgr.c | 52 | ||||
-rw-r--r-- | drivers/fpga/fpga-region.c | 14 |
2 files changed, 48 insertions, 18 deletions
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. */ @@ -491,12 +482,41 @@ 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 * @name: fpga manager name diff --git a/drivers/fpga/fpga-region.c b/drivers/fpga/fpga-region.c index 120c496eb7bd..1e1640a29306 100644 --- a/drivers/fpga/fpga-region.c +++ b/drivers/fpga/fpga-region.c @@ -125,7 +125,7 @@ static void fpga_region_put(struct fpga_region *region) } /** - * fpga_region_get_manager - get exclusive reference for FPGA manager + * fpga_region_get_manager - get reference for FPGA manager * @region: FPGA region * * Get FPGA Manager from "fpga-mgr" property or from ancestor region. @@ -233,6 +233,7 @@ static int fpga_region_get_bridges(struct fpga_region *region, static int fpga_region_program_fpga(struct fpga_region *region, struct device_node *overlay) { + struct device *dev = ®ion->dev; struct fpga_manager *mgr; int ret; @@ -249,10 +250,16 @@ static int fpga_region_program_fpga(struct fpga_region *region, goto err_put_region; } + ret = fpga_mgr_lock(mgr); + if (ret) { + dev_err(dev, "FPGA manager is busy\n"); + goto err_put_mgr; + } + ret = fpga_region_get_bridges(region, overlay); if (ret) { pr_err("failed to get fpga region bridges\n"); - goto err_put_mgr; + goto err_unlock_mgr; } ret = fpga_bridges_disable(®ion->bridge_list); @@ -273,6 +280,7 @@ static int fpga_region_program_fpga(struct fpga_region *region, goto err_put_br; } + fpga_mgr_unlock(mgr); fpga_mgr_put(mgr); fpga_region_put(region); @@ -280,6 +288,8 @@ static int fpga_region_program_fpga(struct fpga_region *region, err_put_br: fpga_bridges_put(®ion->bridge_list); +err_unlock_mgr: + fpga_mgr_unlock(mgr); err_put_mgr: fpga_mgr_put(mgr); err_put_region: |