diff options
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/kho_radix_tree.h | 34 |
1 files changed, 16 insertions, 18 deletions
diff --git a/include/linux/kho_radix_tree.h b/include/linux/kho_radix_tree.h index 84e918b96e53..9157fe08f9ce 100644 --- a/include/linux/kho_radix_tree.h +++ b/include/linux/kho_radix_tree.h @@ -11,15 +11,19 @@ /** * DOC: Kexec Handover Radix Tree * - * This is a radix tree implementation for tracking physical memory pages - * across kexec transitions. It was developed for the KHO mechanism but is - * designed for broader use by any subsystem that needs to preserve pages. + * This is a radix tree implementation for tracking numeric keys across kexec + * transitions. It was developed for the KHO preserved memory map but is + * designed for broader use by any subsystem that needs to track keys. + * Conceptually speaking, the data structure is similar to a set. It tracks the + * presence or absence of numeric keys. * * The radix tree is a multi-level tree where leaf nodes are bitmaps - * representing individual pages. To allow pages of different sizes (orders) + * representing individual keys. + * + * For the KHO preserved memory map, to allow pages of different sizes (orders) * to be stored efficiently in a single tree, it uses a unique key encoding - * scheme. Each key is an unsigned long that combines a page's physical - * address and its order. + * scheme. Each key is an unsigned long that combines a page's physical address + * and its order. * * Client code is responsible for allocating the root node of the tree, * initializing the mutex lock, and managing its lifecycle. It must use the @@ -34,30 +38,24 @@ struct kho_radix_tree { struct mutex lock; /* protects the tree's structure and root pointer */ }; -typedef int (*kho_radix_tree_walk_callback_t)(phys_addr_t phys, - unsigned int order); +typedef int (*kho_radix_tree_walk_callback_t)(unsigned long key); #ifdef CONFIG_KEXEC_HANDOVER -int kho_radix_add_page(struct kho_radix_tree *tree, unsigned long pfn, - unsigned int order); - -void kho_radix_del_page(struct kho_radix_tree *tree, unsigned long pfn, - unsigned int order); - +int kho_radix_add_key(struct kho_radix_tree *tree, unsigned long key); +void kho_radix_del_key(struct kho_radix_tree *tree, unsigned long key); int kho_radix_walk_tree(struct kho_radix_tree *tree, kho_radix_tree_walk_callback_t cb); #else /* #ifdef CONFIG_KEXEC_HANDOVER */ -static inline int kho_radix_add_page(struct kho_radix_tree *tree, long pfn, - unsigned int order) +static inline int kho_radix_add_key(struct kho_radix_tree *tree, unsigned long key) { return -EOPNOTSUPP; } -static inline void kho_radix_del_page(struct kho_radix_tree *tree, - unsigned long pfn, unsigned int order) { } +static inline void kho_radix_del_key(struct kho_radix_tree *tree, + unsigned long key) { } static inline int kho_radix_walk_tree(struct kho_radix_tree *tree, kho_radix_tree_walk_callback_t cb) |