aboutsummaryrefslogtreecommitdiff
path: root/sys/compat/linuxkpi/common/include/linux/scatterlist.h
diff options
context:
space:
mode:
Diffstat (limited to 'sys/compat/linuxkpi/common/include/linux/scatterlist.h')
-rw-r--r--sys/compat/linuxkpi/common/include/linux/scatterlist.h279
1 files changed, 279 insertions, 0 deletions
diff --git a/sys/compat/linuxkpi/common/include/linux/scatterlist.h b/sys/compat/linuxkpi/common/include/linux/scatterlist.h
new file mode 100644
index 000000000000..5aa8d654b504
--- /dev/null
+++ b/sys/compat/linuxkpi/common/include/linux/scatterlist.h
@@ -0,0 +1,279 @@
+/*-
+ * Copyright (c) 2010 Isilon Systems, Inc.
+ * Copyright (c) 2010 iX Systems, Inc.
+ * Copyright (c) 2010 Panasas, Inc.
+ * Copyright (c) 2013-2015 Mellanox Technologies, Ltd.
+ * Copyright (c) 2015 Matthew Dillon <dillon@backplane.com>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice unmodified, this list of conditions, and the following
+ * disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ */
+#ifndef _LINUX_SCATTERLIST_H_
+#define _LINUX_SCATTERLIST_H_
+
+#include <linux/page.h>
+#include <linux/slab.h>
+
+struct scatterlist {
+ union {
+ struct page *page;
+ struct scatterlist *sg;
+ } sl_un;
+ dma_addr_t address;
+ unsigned long offset;
+ uint32_t length;
+ uint32_t flags;
+};
+
+struct sg_table {
+ struct scatterlist *sgl;
+ unsigned int nents;
+ unsigned int orig_nents;
+};
+
+struct sg_page_iter {
+ struct scatterlist *sg;
+ unsigned int sg_pgoffset;
+ unsigned int maxents;
+};
+
+#define SG_MAX_SINGLE_ALLOC (PAGE_SIZE / sizeof(struct scatterlist))
+
+#define sg_dma_address(sg) (sg)->address
+#define sg_dma_len(sg) (sg)->length
+#define sg_page(sg) (sg)->sl_un.page
+#define sg_scatternext(sg) (sg)->sl_un.sg
+
+#define SG_END 0x01
+#define SG_CHAIN 0x02
+
+static inline void
+sg_set_page(struct scatterlist *sg, struct page *page, unsigned int len,
+ unsigned int offset)
+{
+ sg_page(sg) = page;
+ sg_dma_len(sg) = len;
+ sg->offset = offset;
+ if (offset > PAGE_SIZE)
+ panic("sg_set_page: Invalid offset %d\n", offset);
+}
+
+static inline void
+sg_set_buf(struct scatterlist *sg, const void *buf, unsigned int buflen)
+{
+ sg_set_page(sg, virt_to_page(buf), buflen,
+ ((uintptr_t)buf) & (PAGE_SIZE - 1));
+}
+
+static inline void
+sg_init_table(struct scatterlist *sg, unsigned int nents)
+{
+ bzero(sg, sizeof(*sg) * nents);
+ sg[nents - 1].flags = SG_END;
+}
+
+static inline struct scatterlist *
+sg_next(struct scatterlist *sg)
+{
+ if (sg->flags & SG_END)
+ return (NULL);
+ sg++;
+ if (sg->flags & SG_CHAIN)
+ sg = sg_scatternext(sg);
+ return (sg);
+}
+
+static inline vm_paddr_t
+sg_phys(struct scatterlist *sg)
+{
+ return sg_page(sg)->phys_addr + sg->offset;
+}
+
+static inline void
+sg_chain(struct scatterlist *prv, unsigned int prv_nents,
+ struct scatterlist *sgl)
+{
+ struct scatterlist *sg = &prv[prv_nents - 1];
+
+ sg->offset = 0;
+ sg->length = 0;
+ sg->flags = SG_CHAIN;
+ sg->sl_un.sg = sgl;
+}
+
+static inline void
+sg_mark_end(struct scatterlist *sg)
+{
+ sg->flags = SG_END;
+}
+
+static inline void
+__sg_free_table(struct sg_table *table, unsigned int max_ents)
+{
+ struct scatterlist *sgl, *next;
+
+ if (unlikely(!table->sgl))
+ return;
+
+ sgl = table->sgl;
+ while (table->orig_nents) {
+ unsigned int alloc_size = table->orig_nents;
+ unsigned int sg_size;
+
+ if (alloc_size > max_ents) {
+ next = sgl[max_ents - 1].sl_un.sg;
+ alloc_size = max_ents;
+ sg_size = alloc_size - 1;
+ } else {
+ sg_size = alloc_size;
+ next = NULL;
+ }
+
+ table->orig_nents -= sg_size;
+ kfree(sgl);
+ sgl = next;
+ }
+
+ table->sgl = NULL;
+}
+
+static inline void
+sg_free_table(struct sg_table *table)
+{
+ __sg_free_table(table, SG_MAX_SINGLE_ALLOC);
+}
+
+static inline int
+__sg_alloc_table(struct sg_table *table, unsigned int nents,
+ unsigned int max_ents, gfp_t gfp_mask)
+{
+ struct scatterlist *sg, *prv;
+ unsigned int left;
+
+ memset(table, 0, sizeof(*table));
+
+ if (nents == 0)
+ return -EINVAL;
+ left = nents;
+ prv = NULL;
+ do {
+ unsigned int sg_size;
+ unsigned int alloc_size = left;
+
+ if (alloc_size > max_ents) {
+ alloc_size = max_ents;
+ sg_size = alloc_size - 1;
+ } else
+ sg_size = alloc_size;
+
+ left -= sg_size;
+
+ sg = kmalloc(alloc_size * sizeof(struct scatterlist), gfp_mask);
+ if (unlikely(!sg)) {
+ if (prv)
+ table->nents = ++table->orig_nents;
+
+ return -ENOMEM;
+ }
+ sg_init_table(sg, alloc_size);
+ table->nents = table->orig_nents += sg_size;
+
+ if (prv)
+ sg_chain(prv, max_ents, sg);
+ else
+ table->sgl = sg;
+
+ if (!left)
+ sg_mark_end(&sg[sg_size - 1]);
+
+ prv = sg;
+ } while (left);
+
+ return 0;
+}
+
+static inline int
+sg_alloc_table(struct sg_table *table, unsigned int nents, gfp_t gfp_mask)
+{
+ int ret;
+
+ ret = __sg_alloc_table(table, nents, SG_MAX_SINGLE_ALLOC,
+ gfp_mask);
+ if (unlikely(ret))
+ __sg_free_table(table, SG_MAX_SINGLE_ALLOC);
+
+ return ret;
+}
+
+static inline void
+_sg_iter_next(struct sg_page_iter *iter)
+{
+ struct scatterlist *sg;
+ unsigned int pgcount;
+
+ sg = iter->sg;
+ pgcount = (sg->offset + sg->length + PAGE_SIZE - 1) >> PAGE_SHIFT;
+
+ ++iter->sg_pgoffset;
+ while (iter->sg_pgoffset >= pgcount) {
+ iter->sg_pgoffset -= pgcount;
+ sg = sg_next(sg);
+ --iter->maxents;
+ if (sg == NULL || iter->maxents == 0)
+ break;
+ pgcount = (sg->offset + sg->length + PAGE_SIZE - 1) >> PAGE_SHIFT;
+ }
+ iter->sg = sg;
+}
+
+static inline void
+_sg_iter_init(struct scatterlist *sgl, struct sg_page_iter *iter,
+ unsigned int nents, unsigned long pgoffset)
+{
+ if (nents) {
+ iter->sg = sgl;
+ iter->sg_pgoffset = pgoffset - 1;
+ iter->maxents = nents;
+ _sg_iter_next(iter);
+ } else {
+ iter->sg = NULL;
+ iter->sg_pgoffset = 0;
+ iter->maxents = 0;
+ }
+}
+
+static inline dma_addr_t
+sg_page_iter_dma_address(struct sg_page_iter *spi)
+{
+ return spi->sg->address + (spi->sg_pgoffset << PAGE_SHIFT);
+}
+
+#define for_each_sg_page(sgl, iter, nents, pgoffset) \
+ for (_sg_iter_init(sgl, iter, nents, pgoffset); \
+ (iter)->sg; _sg_iter_next(iter))
+
+#define for_each_sg(sglist, sg, sgmax, _itr) \
+ for (_itr = 0, sg = (sglist); _itr < (sgmax); _itr++, sg = sg_next(sg))
+
+#endif /* _LINUX_SCATTERLIST_H_ */