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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /include/linux/pagevec.h
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'include/linux/pagevec.h')
-rw-r--r--include/linux/pagevec.h139
1 files changed, 139 insertions, 0 deletions
diff --git a/include/linux/pagevec.h b/include/linux/pagevec.h
new file mode 100644
index 000000000..215eb6c3b
--- /dev/null
+++ b/include/linux/pagevec.h
@@ -0,0 +1,139 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * include/linux/pagevec.h
+ *
+ * In many places it is efficient to batch an operation up against multiple
+ * pages. A pagevec is a multipage container which is used for that.
+ */
+
+#ifndef _LINUX_PAGEVEC_H
+#define _LINUX_PAGEVEC_H
+
+#include <linux/xarray.h>
+
+/* 15 pointers + header align the pagevec structure to a power of two */
+#define PAGEVEC_SIZE 15
+
+struct page;
+struct folio;
+struct address_space;
+
+/* Layout must match folio_batch */
+struct pagevec {
+ unsigned char nr;
+ bool percpu_pvec_drained;
+ struct page *pages[PAGEVEC_SIZE];
+};
+
+void __pagevec_release(struct pagevec *pvec);
+unsigned pagevec_lookup_range_tag(struct pagevec *pvec,
+ struct address_space *mapping, pgoff_t *index, pgoff_t end,
+ xa_mark_t tag);
+static inline unsigned pagevec_lookup_tag(struct pagevec *pvec,
+ struct address_space *mapping, pgoff_t *index, xa_mark_t tag)
+{
+ return pagevec_lookup_range_tag(pvec, mapping, index, (pgoff_t)-1, tag);
+}
+
+static inline void pagevec_init(struct pagevec *pvec)
+{
+ pvec->nr = 0;
+ pvec->percpu_pvec_drained = false;
+}
+
+static inline void pagevec_reinit(struct pagevec *pvec)
+{
+ pvec->nr = 0;
+}
+
+static inline unsigned pagevec_count(struct pagevec *pvec)
+{
+ return pvec->nr;
+}
+
+static inline unsigned pagevec_space(struct pagevec *pvec)
+{
+ return PAGEVEC_SIZE - pvec->nr;
+}
+
+/*
+ * Add a page to a pagevec. Returns the number of slots still available.
+ */
+static inline unsigned pagevec_add(struct pagevec *pvec, struct page *page)
+{
+ pvec->pages[pvec->nr++] = page;
+ return pagevec_space(pvec);
+}
+
+static inline void pagevec_release(struct pagevec *pvec)
+{
+ if (pagevec_count(pvec))
+ __pagevec_release(pvec);
+}
+
+/**
+ * struct folio_batch - A collection of folios.
+ *
+ * The folio_batch is used to amortise the cost of retrieving and
+ * operating on a set of folios. The order of folios in the batch may be
+ * significant (eg delete_from_page_cache_batch()). Some users of the
+ * folio_batch store "exceptional" entries in it which can be removed
+ * by calling folio_batch_remove_exceptionals().
+ */
+struct folio_batch {
+ unsigned char nr;
+ bool percpu_pvec_drained;
+ struct folio *folios[PAGEVEC_SIZE];
+};
+
+/* Layout must match pagevec */
+static_assert(sizeof(struct pagevec) == sizeof(struct folio_batch));
+static_assert(offsetof(struct pagevec, pages) ==
+ offsetof(struct folio_batch, folios));
+
+/**
+ * folio_batch_init() - Initialise a batch of folios
+ * @fbatch: The folio batch.
+ *
+ * A freshly initialised folio_batch contains zero folios.
+ */
+static inline void folio_batch_init(struct folio_batch *fbatch)
+{
+ fbatch->nr = 0;
+ fbatch->percpu_pvec_drained = false;
+}
+
+static inline unsigned int folio_batch_count(struct folio_batch *fbatch)
+{
+ return fbatch->nr;
+}
+
+static inline unsigned int fbatch_space(struct folio_batch *fbatch)
+{
+ return PAGEVEC_SIZE - fbatch->nr;
+}
+
+/**
+ * folio_batch_add() - Add a folio to a batch.
+ * @fbatch: The folio batch.
+ * @folio: The folio to add.
+ *
+ * The folio is added to the end of the batch.
+ * The batch must have previously been initialised using folio_batch_init().
+ *
+ * Return: The number of slots still available.
+ */
+static inline unsigned folio_batch_add(struct folio_batch *fbatch,
+ struct folio *folio)
+{
+ fbatch->folios[fbatch->nr++] = folio;
+ return fbatch_space(fbatch);
+}
+
+static inline void folio_batch_release(struct folio_batch *fbatch)
+{
+ pagevec_release((struct pagevec *)fbatch);
+}
+
+void folio_batch_remove_exceptionals(struct folio_batch *fbatch);
+#endif /* _LINUX_PAGEVEC_H */