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Diffstat (limited to 'include/linux/folio_queue.h')
| -rw-r--r-- | include/linux/folio_queue.h | 138 |
1 files changed, 138 insertions, 0 deletions
diff --git a/include/linux/folio_queue.h b/include/linux/folio_queue.h new file mode 100644 index 000000000000..52773613bf23 --- /dev/null +++ b/include/linux/folio_queue.h @@ -0,0 +1,138 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* Queue of folios definitions + * + * Copyright (C) 2024 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + */ + +#ifndef _LINUX_FOLIO_QUEUE_H +#define _LINUX_FOLIO_QUEUE_H + +#include <linux/pagevec.h> + +/* + * Segment in a queue of running buffers. Each segment can hold a number of + * folios and a portion of the queue can be referenced with the ITER_FOLIOQ + * iterator. The possibility exists of inserting non-folio elements into the + * queue (such as gaps). + * + * Explicit prev and next pointers are used instead of a list_head to make it + * easier to add segments to tail and remove them from the head without the + * need for a lock. + */ +struct folio_queue { + struct folio_batch vec; /* Folios in the queue segment */ + u8 orders[PAGEVEC_SIZE]; /* Order of each folio */ + struct folio_queue *next; /* Next queue segment or NULL */ + struct folio_queue *prev; /* Previous queue segment of NULL */ + unsigned long marks; /* 1-bit mark per folio */ + unsigned long marks2; /* Second 1-bit mark per folio */ +#if PAGEVEC_SIZE > BITS_PER_LONG +#error marks is not big enough +#endif +}; + +static inline void folioq_init(struct folio_queue *folioq) +{ + folio_batch_init(&folioq->vec); + folioq->next = NULL; + folioq->prev = NULL; + folioq->marks = 0; + folioq->marks2 = 0; +} + +static inline unsigned int folioq_nr_slots(const struct folio_queue *folioq) +{ + return PAGEVEC_SIZE; +} + +static inline unsigned int folioq_count(struct folio_queue *folioq) +{ + return folio_batch_count(&folioq->vec); +} + +static inline bool folioq_full(struct folio_queue *folioq) +{ + //return !folio_batch_space(&folioq->vec); + return folioq_count(folioq) >= folioq_nr_slots(folioq); +} + +static inline bool folioq_is_marked(const struct folio_queue *folioq, unsigned int slot) +{ + return test_bit(slot, &folioq->marks); +} + +static inline void folioq_mark(struct folio_queue *folioq, unsigned int slot) +{ + set_bit(slot, &folioq->marks); +} + +static inline void folioq_unmark(struct folio_queue *folioq, unsigned int slot) +{ + clear_bit(slot, &folioq->marks); +} + +static inline bool folioq_is_marked2(const struct folio_queue *folioq, unsigned int slot) +{ + return test_bit(slot, &folioq->marks2); +} + +static inline void folioq_mark2(struct folio_queue *folioq, unsigned int slot) +{ + set_bit(slot, &folioq->marks2); +} + +static inline void folioq_unmark2(struct folio_queue *folioq, unsigned int slot) +{ + clear_bit(slot, &folioq->marks2); +} + +static inline unsigned int __folio_order(struct folio *folio) +{ + if (!folio_test_large(folio)) + return 0; + return folio->_flags_1 & 0xff; +} + +static inline unsigned int folioq_append(struct folio_queue *folioq, struct folio *folio) +{ + unsigned int slot = folioq->vec.nr++; + + folioq->vec.folios[slot] = folio; + folioq->orders[slot] = __folio_order(folio); + return slot; +} + +static inline unsigned int folioq_append_mark(struct folio_queue *folioq, struct folio *folio) +{ + unsigned int slot = folioq->vec.nr++; + + folioq->vec.folios[slot] = folio; + folioq->orders[slot] = __folio_order(folio); + folioq_mark(folioq, slot); + return slot; +} + +static inline struct folio *folioq_folio(const struct folio_queue *folioq, unsigned int slot) +{ + return folioq->vec.folios[slot]; +} + +static inline unsigned int folioq_folio_order(const struct folio_queue *folioq, unsigned int slot) +{ + return folioq->orders[slot]; +} + +static inline size_t folioq_folio_size(const struct folio_queue *folioq, unsigned int slot) +{ + return PAGE_SIZE << folioq_folio_order(folioq, slot); +} + +static inline void folioq_clear(struct folio_queue *folioq, unsigned int slot) +{ + folioq->vec.folios[slot] = NULL; + folioq_unmark(folioq, slot); + folioq_unmark2(folioq, slot); +} + +#endif /* _LINUX_FOLIO_QUEUE_H */ |