Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  1) /* SPDX-License-Identifier: GPL-2.0 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  2) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  3) #ifndef DEFERRED_FREE_HELPER_H
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  4) #define DEFERRED_FREE_HELPER_H
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  5) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  6) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  7)  * df_reason - enum for reason why item was freed
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  8)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  9)  * This provides a reason for why the free function was called
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10)  * on the item. This is useful when deferred_free is used in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11)  * combination with a pagepool, so under pressure the page can
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12)  * be immediately freed.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14)  * DF_NORMAL:         Normal deferred free
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16)  * DF_UNDER_PRESSURE: Free was called because the system
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17)  *                    is under memory pressure. Usually
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18)  *                    from a shrinker. Avoid allocating
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19)  *                    memory in the free call, as it may
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20)  *                    fail.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) enum df_reason {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) 	DF_NORMAL,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) 	DF_UNDER_PRESSURE,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28)  * deferred_freelist_item - item structure for deferred freelist
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30)  * This is to be added to the structure for whatever you want to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31)  * defer freeing on.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33)  * @nr_pages: number of pages used by item to be freed
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34)  * @free: function pointer to be called when freeing the item
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35)  * @list: list entry for the deferred list
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) struct deferred_freelist_item {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) 	size_t nr_pages;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) 	void (*free)(struct deferred_freelist_item *i,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) 		     enum df_reason reason);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) 	struct list_head list;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45)  * deferred_free - call to add item to the deferred free list
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47)  * @item: Pointer to deferred_freelist_item field of a structure
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48)  * @free: Function pointer to the free call
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49)  * @nr_pages: number of pages to be freed
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) void deferred_free(struct deferred_freelist_item *item,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) 		   void (*free)(struct deferred_freelist_item *i,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) 				enum df_reason reason),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) 		   size_t nr_pages);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) unsigned long get_freelist_nr_pages(void);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) #endif