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b7c0e1ecee
The current implementation of the fpga region assumes that the low-level
module registers a driver for the parent device and uses its owner pointer
to take the module's refcount. This approach is problematic since it can
lead to a null pointer dereference while attempting to get the region
during programming if the parent device does not have a driver.
To address this problem, add a module owner pointer to the fpga_region
struct and use it to take the module's refcount. Modify the functions for
registering a region to take an additional owner module parameter and
rename them to avoid conflicts. Use the old function names for helper
macros that automatically set the module that registers the region as the
owner. This ensures compatibility with existing low-level control modules
and reduces the chances of registering a region without setting the owner.
Also, update the documentation to keep it consistent with the new interface
for registering an fpga region.
Fixes: 0fa20cdfcc ("fpga: fpga-region: device tree control for FPGA")
Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Suggested-by: Xu Yilun <yilun.xu@intel.com>
Reviewed-by: Russ Weight <russ.weight@linux.dev>
Signed-off-by: Marco Pagani <marpagan@redhat.com>
Acked-by: Xu Yilun <yilun.xu@intel.com>
Link: https://lore.kernel.org/r/20240419083601.77403-1-marpagan@redhat.com
Signed-off-by: Xu Yilun <yilun.xu@linux.intel.com>
77 lines
2.4 KiB
C
77 lines
2.4 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _FPGA_REGION_H
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#define _FPGA_REGION_H
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#include <linux/device.h>
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#include <linux/fpga/fpga-mgr.h>
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#include <linux/fpga/fpga-bridge.h>
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struct fpga_region;
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/**
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* struct fpga_region_info - collection of parameters an FPGA Region
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* @mgr: fpga region manager
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* @compat_id: FPGA region id for compatibility check.
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* @priv: fpga region private data
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* @get_bridges: optional function to get bridges to a list
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*
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* fpga_region_info contains parameters for the register_full function.
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* These are separated into an info structure because they some are optional
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* others could be added to in the future. The info structure facilitates
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* maintaining a stable API.
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*/
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struct fpga_region_info {
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struct fpga_manager *mgr;
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struct fpga_compat_id *compat_id;
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void *priv;
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int (*get_bridges)(struct fpga_region *region);
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};
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/**
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* struct fpga_region - FPGA Region structure
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* @dev: FPGA Region device
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* @mutex: enforces exclusive reference to region
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* @bridge_list: list of FPGA bridges specified in region
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* @mgr: FPGA manager
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* @info: FPGA image info
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* @compat_id: FPGA region id for compatibility check.
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* @ops_owner: module containing the get_bridges function
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* @priv: private data
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* @get_bridges: optional function to get bridges to a list
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*/
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struct fpga_region {
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struct device dev;
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struct mutex mutex; /* for exclusive reference to region */
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struct list_head bridge_list;
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struct fpga_manager *mgr;
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struct fpga_image_info *info;
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struct fpga_compat_id *compat_id;
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struct module *ops_owner;
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void *priv;
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int (*get_bridges)(struct fpga_region *region);
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};
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#define to_fpga_region(d) container_of(d, struct fpga_region, dev)
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struct fpga_region *
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fpga_region_class_find(struct device *start, const void *data,
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int (*match)(struct device *, const void *));
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int fpga_region_program_fpga(struct fpga_region *region);
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#define fpga_region_register_full(parent, info) \
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__fpga_region_register_full(parent, info, THIS_MODULE)
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struct fpga_region *
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__fpga_region_register_full(struct device *parent, const struct fpga_region_info *info,
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struct module *owner);
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#define fpga_region_register(parent, mgr, get_bridges) \
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__fpga_region_register(parent, mgr, get_bridges, THIS_MODULE)
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struct fpga_region *
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__fpga_region_register(struct device *parent, struct fpga_manager *mgr,
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int (*get_bridges)(struct fpga_region *), struct module *owner);
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void fpga_region_unregister(struct fpga_region *region);
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#endif /* _FPGA_REGION_H */
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