diff options
Diffstat (limited to 'include/linux/liveupdate.h')
| -rw-r--r-- | include/linux/liveupdate.h | 147 |
1 files changed, 147 insertions, 0 deletions
diff --git a/include/linux/liveupdate.h b/include/linux/liveupdate.h index a7f6ee5b6771..fe82a6c3005f 100644 --- a/include/linux/liveupdate.h +++ b/include/linux/liveupdate.h @@ -11,10 +11,13 @@ #include <linux/compiler.h> #include <linux/kho/abi/luo.h> #include <linux/list.h> +#include <linux/mutex.h> #include <linux/types.h> #include <uapi/linux/liveupdate.h> struct liveupdate_file_handler; +struct liveupdate_flb; +struct liveupdate_session; struct file; /** @@ -99,6 +102,118 @@ struct liveupdate_file_handler { * registered file handlers. */ struct list_head __private list; + /* A list of FLB dependencies. */ + struct list_head __private flb_list; +}; + +/** + * struct liveupdate_flb_op_args - Arguments for FLB operation callbacks. + * @flb: The global FLB instance for which this call is performed. + * @data: For .preserve(): [OUT] The callback sets this field. + * For .unpreserve(): [IN] The handle from .preserve(). + * For .retrieve(): [IN] The handle from .preserve(). + * @obj: For .preserve(): [OUT] Sets this to the live object. + * For .retrieve(): [OUT] Sets this to the live object. + * For .finish(): [IN] The live object from .retrieve(). + * + * This structure bundles all parameters for the FLB operation callbacks. + */ +struct liveupdate_flb_op_args { + struct liveupdate_flb *flb; + u64 data; + void *obj; +}; + +/** + * struct liveupdate_flb_ops - Callbacks for global File-Lifecycle-Bound data. + * @preserve: Called when the first file using this FLB is preserved. + * The callback must save its state and return a single, + * self-contained u64 handle by setting the 'argp->data' + * field and 'argp->obj'. + * @unpreserve: Called when the last file using this FLB is unpreserved + * (aborted before reboot). Receives the handle via + * 'argp->data' and live object via 'argp->obj'. + * @retrieve: Called on-demand in the new kernel, the first time a + * component requests access to the shared object. It receives + * the preserved handle via 'argp->data' and must reconstruct + * the live object, returning it by setting the 'argp->obj' + * field. + * @finish: Called in the new kernel when the last file using this FLB + * is finished. Receives the live object via 'argp->obj' for + * cleanup. + * @owner: Module reference + * + * Operations that manage global shared data with file bound lifecycle, + * triggered by the first file that uses it and concluded by the last file that + * uses it, across all sessions. + */ +struct liveupdate_flb_ops { + int (*preserve)(struct liveupdate_flb_op_args *argp); + void (*unpreserve)(struct liveupdate_flb_op_args *argp); + int (*retrieve)(struct liveupdate_flb_op_args *argp); + void (*finish)(struct liveupdate_flb_op_args *argp); + struct module *owner; +}; + +/* + * struct luo_flb_private_state - Private FLB state structures. + * @count: The number of preserved files currently depending on this FLB. + * This is used to trigger the preserve/unpreserve/finish ops on the + * first/last file. + * @data: The opaque u64 handle returned by .preserve() or passed to + * .retrieve(). + * @obj: The live kernel object returned by .preserve() or .retrieve(). + * @lock: A mutex that protects all fields within this structure, providing + * the synchronization service for the FLB's ops. + * @finished: True once the FLB's finish() callback has run. + * @retrieved: True once the FLB's retrieve() callback has run. + */ +struct luo_flb_private_state { + long count; + u64 data; + void *obj; + struct mutex lock; + bool finished; + bool retrieved; +}; + +/* + * struct luo_flb_private - Keep separate incoming and outgoing states. + * @list: A global list of registered FLBs. + * @outgoing: The runtime state for the pre-reboot + * (preserve/unpreserve) lifecycle. + * @incoming: The runtime state for the post-reboot (retrieve/finish) + * lifecycle. + * @users: With how many File-Handlers this FLB is registered. + * @initialized: true when private fields have been initialized. + */ +struct luo_flb_private { + struct list_head list; + struct luo_flb_private_state outgoing; + struct luo_flb_private_state incoming; + int users; + bool initialized; +}; + +/** + * struct liveupdate_flb - A global definition for a shared data object. + * @ops: Callback functions + * @compatible: The compatibility string (e.g., "iommu-core-v1" + * that uniquely identifies the FLB type this handler + * supports. This is matched against the compatible string + * associated with individual &struct liveupdate_flb + * instances. + * + * This struct is the "template" that a driver registers to define a shared, + * file-lifecycle-bound object. The actual runtime state (the live object, + * refcount, etc.) is managed privately by the LUO core. + */ +struct liveupdate_flb { + const struct liveupdate_flb_ops *ops; + const char compatible[LIVEUPDATE_FLB_COMPAT_LENGTH]; + + /* private: */ + struct luo_flb_private __private private; }; #ifdef CONFIG_LIVEUPDATE @@ -112,6 +227,14 @@ int liveupdate_reboot(void); int liveupdate_register_file_handler(struct liveupdate_file_handler *fh); int liveupdate_unregister_file_handler(struct liveupdate_file_handler *fh); +int liveupdate_register_flb(struct liveupdate_file_handler *fh, + struct liveupdate_flb *flb); +int liveupdate_unregister_flb(struct liveupdate_file_handler *fh, + struct liveupdate_flb *flb); + +int liveupdate_flb_get_incoming(struct liveupdate_flb *flb, void **objp); +int liveupdate_flb_get_outgoing(struct liveupdate_flb *flb, void **objp); + #else /* CONFIG_LIVEUPDATE */ static inline bool liveupdate_enabled(void) @@ -134,5 +257,29 @@ static inline int liveupdate_unregister_file_handler(struct liveupdate_file_hand return -EOPNOTSUPP; } +static inline int liveupdate_register_flb(struct liveupdate_file_handler *fh, + struct liveupdate_flb *flb) +{ + return -EOPNOTSUPP; +} + +static inline int liveupdate_unregister_flb(struct liveupdate_file_handler *fh, + struct liveupdate_flb *flb) +{ + return -EOPNOTSUPP; +} + +static inline int liveupdate_flb_get_incoming(struct liveupdate_flb *flb, + void **objp) +{ + return -EOPNOTSUPP; +} + +static inline int liveupdate_flb_get_outgoing(struct liveupdate_flb *flb, + void **objp) +{ + return -EOPNOTSUPP; +} + #endif /* CONFIG_LIVEUPDATE */ #endif /* _LINUX_LIVEUPDATE_H */ |