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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>
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@ -48,8 +48,20 @@ To get/put a reference to a FPGA manager:
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struct fpga_manager *fpga_mgr_get(struct device *dev);
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void fpga_mgr_put(struct fpga_manager *mgr);
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Given a DT node or device, get an exclusive reference to a FPGA manager.
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fpga_mgr_put releases the reference.
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Given a DT node or device, get a reference to a FPGA manager. This pointer
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can be saved until you are ready to program the FPGA. fpga_mgr_put releases
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the reference.
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To get exclusive control of a FPGA manager:
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-------------------------------------------
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int fpga_mgr_lock(struct fpga_manager *mgr);
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void fpga_mgr_unlock(struct fpga_manager *mgr);
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The user should call fpga_mgr_lock and verify that it returns 0 before
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attempting to program the FPGA. Likewise, the user should call
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fpga_mgr_unlock when done programming the FPGA.
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To register or unregister the low level FPGA-specific driver:
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@ -67,13 +79,21 @@ device."
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How to write an image buffer to a supported FPGA
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================================================
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/* Include to get the API */
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#include <linux/fpga/fpga-mgr.h>
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struct fpga_manager *mgr;
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struct fpga_image_info *info;
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int ret;
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/*
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* Get a reference to FPGA manager. The manager is not locked, so you can
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* hold onto this reference without it preventing programming.
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*
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* This example uses the device node of the manager. Alternatively, use
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* fpga_mgr_get(dev) instead if you have the device.
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*/
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mgr = of_fpga_mgr_get(mgr_node);
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/* struct with information about the FPGA image to program. */
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info = fpga_image_info_alloc(dev);
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@ -99,17 +119,14 @@ if (image is in a scatter gather table) {
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}
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/*
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* Get a reference to FPGA manager. This example uses the device node of the
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* manager. You could use fpga_mgr_get() instead if you have the device instead
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* of the device node.
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*/
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mgr = of_fpga_mgr_get(mgr_node);
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/* Get exclusive control of FPGA manager */
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ret = fpga_mgr_lock(mgr);
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/* Load the buffer to the FPGA */
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ret = fpga_mgr_buf_load(mgr, &info, buf, count);
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/* Release the FPGA manager */
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fpga_mgr_unlock(mgr);
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fpga_mgr_put(mgr);
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/* Deallocate the image info if you're done with it */
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@ -410,28 +410,19 @@ ATTRIBUTE_GROUPS(fpga_mgr);
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static struct fpga_manager *__fpga_mgr_get(struct device *dev)
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{
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struct fpga_manager *mgr;
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int ret = -ENODEV;
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mgr = to_fpga_manager(dev);
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if (!mgr)
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goto err_dev;
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/* Get exclusive use of fpga manager */
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if (!mutex_trylock(&mgr->ref_mutex)) {
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ret = -EBUSY;
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goto err_dev;
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}
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if (!try_module_get(dev->parent->driver->owner))
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goto err_ll_mod;
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goto err_dev;
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return mgr;
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err_ll_mod:
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mutex_unlock(&mgr->ref_mutex);
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err_dev:
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put_device(dev);
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return ERR_PTR(ret);
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return ERR_PTR(-ENODEV);
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}
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static int fpga_mgr_dev_match(struct device *dev, const void *data)
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@ -440,10 +431,10 @@ static int fpga_mgr_dev_match(struct device *dev, const void *data)
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}
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/**
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* fpga_mgr_get - get an exclusive reference to a fpga mgr
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* fpga_mgr_get - get a reference to a fpga mgr
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* @dev: parent device that fpga mgr was registered with
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*
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* Given a device, get an exclusive reference to a fpga mgr.
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* Given a device, get a reference to a fpga mgr.
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*
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* Return: fpga manager struct or IS_ERR() condition containing error code.
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*/
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@ -464,10 +455,10 @@ static int fpga_mgr_of_node_match(struct device *dev, const void *data)
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}
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/**
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* of_fpga_mgr_get - get an exclusive reference to a fpga mgr
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* of_fpga_mgr_get - get a reference to a fpga mgr
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* @node: device node
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*
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* Given a device node, get an exclusive reference to a fpga mgr.
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* Given a device node, get a reference to a fpga mgr.
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*
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* Return: fpga manager struct or IS_ERR() condition containing error code.
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*/
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@ -491,11 +482,40 @@ EXPORT_SYMBOL_GPL(of_fpga_mgr_get);
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void fpga_mgr_put(struct fpga_manager *mgr)
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{
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module_put(mgr->dev.parent->driver->owner);
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mutex_unlock(&mgr->ref_mutex);
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put_device(&mgr->dev);
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}
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EXPORT_SYMBOL_GPL(fpga_mgr_put);
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/**
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* fpga_mgr_lock - Lock FPGA manager for exclusive use
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* @mgr: fpga manager
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*
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* Given a pointer to FPGA Manager (from fpga_mgr_get() or
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* of_fpga_mgr_put()) attempt to get the mutex.
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*
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* Return: 0 for success or -EBUSY
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*/
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int fpga_mgr_lock(struct fpga_manager *mgr)
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{
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if (!mutex_trylock(&mgr->ref_mutex)) {
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dev_err(&mgr->dev, "FPGA manager is in use.\n");
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return -EBUSY;
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}
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return 0;
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}
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EXPORT_SYMBOL_GPL(fpga_mgr_lock);
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/**
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* fpga_mgr_unlock - Unlock FPGA manager
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* @mgr: fpga manager
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*/
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void fpga_mgr_unlock(struct fpga_manager *mgr)
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{
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mutex_unlock(&mgr->ref_mutex);
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}
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EXPORT_SYMBOL_GPL(fpga_mgr_unlock);
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/**
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* fpga_mgr_register - register a low level fpga manager driver
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* @dev: fpga manager device from pdev
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@ -125,7 +125,7 @@ static void fpga_region_put(struct fpga_region *region)
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}
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/**
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* fpga_region_get_manager - get exclusive reference for FPGA manager
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* fpga_region_get_manager - get reference for FPGA manager
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* @region: FPGA region
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*
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* Get FPGA Manager from "fpga-mgr" property or from ancestor region.
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@ -233,6 +233,7 @@ static int fpga_region_get_bridges(struct fpga_region *region,
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static int fpga_region_program_fpga(struct fpga_region *region,
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struct device_node *overlay)
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{
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struct device *dev = ®ion->dev;
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struct fpga_manager *mgr;
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int ret;
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@ -249,10 +250,16 @@ static int fpga_region_program_fpga(struct fpga_region *region,
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goto err_put_region;
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}
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ret = fpga_mgr_lock(mgr);
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if (ret) {
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dev_err(dev, "FPGA manager is busy\n");
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goto err_put_mgr;
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}
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ret = fpga_region_get_bridges(region, overlay);
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if (ret) {
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pr_err("failed to get fpga region bridges\n");
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goto err_put_mgr;
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goto err_unlock_mgr;
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}
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ret = fpga_bridges_disable(®ion->bridge_list);
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@ -273,6 +280,7 @@ static int fpga_region_program_fpga(struct fpga_region *region,
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goto err_put_br;
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}
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fpga_mgr_unlock(mgr);
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fpga_mgr_put(mgr);
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fpga_region_put(region);
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@ -280,6 +288,8 @@ static int fpga_region_program_fpga(struct fpga_region *region,
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err_put_br:
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fpga_bridges_put(®ion->bridge_list);
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err_unlock_mgr:
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fpga_mgr_unlock(mgr);
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err_put_mgr:
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fpga_mgr_put(mgr);
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err_put_region:
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@ -155,6 +155,9 @@ void fpga_image_info_free(struct fpga_image_info *info);
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int fpga_mgr_load(struct fpga_manager *mgr, struct fpga_image_info *info);
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int fpga_mgr_lock(struct fpga_manager *mgr);
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void fpga_mgr_unlock(struct fpga_manager *mgr);
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struct fpga_manager *of_fpga_mgr_get(struct device_node *node);
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struct fpga_manager *fpga_mgr_get(struct device *dev);
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