2011-03-21 09:58:24 +00:00
|
|
|
/*-
|
|
|
|
* Copyright (c) 2010 Isilon Systems, Inc.
|
|
|
|
* Copyright (c) 2010 iX Systems, Inc.
|
|
|
|
* Copyright (c) 2010 Panasas, Inc.
|
2014-08-27 13:21:53 +00:00
|
|
|
* Copyright (c) 2013, 2014 Mellanox Technologies, Ltd.
|
2015-10-19 11:09:51 +00:00
|
|
|
* Copyright (c) 2015 Matthew Dillon <dillon@backplane.com>
|
2011-03-21 09:58:24 +00:00
|
|
|
* 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.
|
|
|
|
*/
|
2014-08-27 13:21:53 +00:00
|
|
|
|
2011-03-21 09:58:24 +00:00
|
|
|
#ifndef _LINUX_SCATTERLIST_H_
|
|
|
|
#define _LINUX_SCATTERLIST_H_
|
|
|
|
|
|
|
|
#include <linux/page.h>
|
2014-10-15 13:40:29 +00:00
|
|
|
#include <linux/slab.h>
|
|
|
|
|
|
|
|
/*
|
|
|
|
* SG table design.
|
|
|
|
*
|
|
|
|
* If flags bit 0 is set, then the sg field contains a pointer to the next sg
|
|
|
|
* table list. Otherwise the next entry is at sg + 1, can be determined using
|
|
|
|
* the sg_is_chain() function.
|
|
|
|
*
|
|
|
|
* If flags bit 1 is set, then this sg entry is the last element in a list,
|
|
|
|
* can be determined using the sg_is_last() function.
|
|
|
|
*
|
|
|
|
* See sg_next().
|
|
|
|
*
|
|
|
|
*/
|
2011-03-21 09:58:24 +00:00
|
|
|
|
|
|
|
struct scatterlist {
|
|
|
|
union {
|
|
|
|
struct page *page;
|
|
|
|
struct scatterlist *sg;
|
|
|
|
} sl_un;
|
2011-03-21 21:16:40 +00:00
|
|
|
dma_addr_t address;
|
2011-03-21 09:58:24 +00:00
|
|
|
unsigned long offset;
|
|
|
|
uint32_t length;
|
|
|
|
uint32_t flags;
|
|
|
|
};
|
|
|
|
|
2014-08-27 13:21:53 +00:00
|
|
|
struct sg_table {
|
|
|
|
struct scatterlist *sgl; /* the list */
|
|
|
|
unsigned int nents; /* number of mapped entries */
|
|
|
|
unsigned int orig_nents; /* original size of list */
|
|
|
|
};
|
|
|
|
|
2015-10-19 11:09:51 +00:00
|
|
|
struct sg_page_iter {
|
|
|
|
struct scatterlist *sg;
|
|
|
|
unsigned int sg_pgoffset; /* page index */
|
|
|
|
unsigned int maxents;
|
|
|
|
};
|
|
|
|
|
2014-10-15 13:40:29 +00:00
|
|
|
/*
|
|
|
|
* Maximum number of entries that will be allocated in one piece, if
|
|
|
|
* a list larger than this is required then chaining will be utilized.
|
|
|
|
*/
|
|
|
|
#define SG_MAX_SINGLE_ALLOC (PAGE_SIZE / sizeof(struct scatterlist))
|
|
|
|
|
2011-03-21 09:58:24 +00:00
|
|
|
#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,
|
2015-10-19 11:09:51 +00:00
|
|
|
((uintptr_t)buf) & (PAGE_SIZE - 1));
|
2011-03-21 09:58:24 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
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;
|
|
|
|
}
|
|
|
|
|
2014-10-15 13:40:29 +00:00
|
|
|
/**
|
|
|
|
* sg_chain - Chain two sglists together
|
|
|
|
* @prv: First scatterlist
|
|
|
|
* @prv_nents: Number of entries in prv
|
|
|
|
* @sgl: Second scatterlist
|
|
|
|
*
|
|
|
|
* Description:
|
|
|
|
* Links @prv@ and @sgl@ together, to form a longer scatterlist.
|
|
|
|
*
|
|
|
|
**/
|
|
|
|
static inline void
|
|
|
|
sg_chain(struct scatterlist *prv, unsigned int prv_nents,
|
|
|
|
struct scatterlist *sgl)
|
|
|
|
{
|
|
|
|
/*
|
|
|
|
* offset and length are unused for chain entry. Clear them.
|
|
|
|
*/
|
|
|
|
struct scatterlist *sg = &prv[prv_nents - 1];
|
|
|
|
|
|
|
|
sg->offset = 0;
|
|
|
|
sg->length = 0;
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Indicate a link pointer, and set the link to the second list.
|
|
|
|
*/
|
|
|
|
sg->flags = SG_CHAIN;
|
|
|
|
sg->sl_un.sg = sgl;
|
|
|
|
}
|
|
|
|
|
|
|
|
/**
|
|
|
|
* sg_mark_end - Mark the end of the scatterlist
|
|
|
|
* @sg: SG entryScatterlist
|
|
|
|
*
|
|
|
|
* Description:
|
|
|
|
* Marks the passed in sg entry as the termination point for the sg
|
|
|
|
* table. A call to sg_next() on this entry will return NULL.
|
|
|
|
*
|
|
|
|
**/
|
|
|
|
static inline void sg_mark_end(struct scatterlist *sg)
|
|
|
|
{
|
|
|
|
sg->flags = SG_END;
|
|
|
|
}
|
|
|
|
|
|
|
|
/**
|
|
|
|
* __sg_free_table - Free a previously mapped sg table
|
|
|
|
* @table: The sg table header to use
|
|
|
|
* @max_ents: The maximum number of entries per single scatterlist
|
|
|
|
*
|
|
|
|
* Description:
|
|
|
|
* Free an sg table previously allocated and setup with
|
|
|
|
* __sg_alloc_table(). The @max_ents value must be identical to
|
|
|
|
* that previously used with __sg_alloc_table().
|
|
|
|
*
|
|
|
|
**/
|
|
|
|
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 we have more than max_ents segments left,
|
|
|
|
* then assign 'next' to the sg table after the current one.
|
|
|
|
* sg_size is then one less than alloc size, since the last
|
|
|
|
* element is the chain pointer.
|
|
|
|
*/
|
|
|
|
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;
|
|
|
|
}
|
|
|
|
|
|
|
|
/**
|
|
|
|
* sg_free_table - Free a previously allocated sg table
|
|
|
|
* @table: The mapped sg table header
|
|
|
|
*
|
|
|
|
**/
|
|
|
|
static inline void
|
|
|
|
sg_free_table(struct sg_table *table)
|
|
|
|
{
|
|
|
|
__sg_free_table(table, SG_MAX_SINGLE_ALLOC);
|
|
|
|
}
|
|
|
|
|
|
|
|
/**
|
|
|
|
* __sg_alloc_table - Allocate and initialize an sg table with given allocator
|
|
|
|
* @table: The sg table header to use
|
|
|
|
* @nents: Number of entries in sg list
|
|
|
|
* @max_ents: The maximum number of entries the allocator returns per call
|
|
|
|
* @gfp_mask: GFP allocation mask
|
|
|
|
*
|
|
|
|
* Description:
|
|
|
|
* This function returns a @table @nents long. The allocator is
|
|
|
|
* defined to return scatterlist chunks of maximum size @max_ents.
|
|
|
|
* Thus if @nents is bigger than @max_ents, the scatterlists will be
|
|
|
|
* chained in units of @max_ents.
|
|
|
|
*
|
|
|
|
* Notes:
|
|
|
|
* If this function returns non-0 (eg failure), the caller must call
|
|
|
|
* __sg_free_table() to cleanup any leftover allocations.
|
|
|
|
*
|
|
|
|
**/
|
|
|
|
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, 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)) {
|
|
|
|
/*
|
|
|
|
* Adjust entry count to reflect that the last
|
|
|
|
* entry of the previous table won't be used for
|
|
|
|
* linkage. Without this, sg_kfree() may get
|
|
|
|
* confused.
|
|
|
|
*/
|
|
|
|
if (prv)
|
|
|
|
table->nents = ++table->orig_nents;
|
|
|
|
|
|
|
|
return -ENOMEM;
|
|
|
|
}
|
|
|
|
|
|
|
|
sg_init_table(sg, alloc_size);
|
|
|
|
table->nents = table->orig_nents += sg_size;
|
|
|
|
|
|
|
|
/*
|
|
|
|
* If this is the first mapping, assign the sg table header.
|
|
|
|
* If this is not the first mapping, chain previous part.
|
|
|
|
*/
|
|
|
|
if (prv)
|
|
|
|
sg_chain(prv, max_ents, sg);
|
|
|
|
else
|
|
|
|
table->sgl = sg;
|
|
|
|
|
|
|
|
/*
|
|
|
|
* If no more entries after this one, mark the end
|
|
|
|
*/
|
|
|
|
if (!left)
|
|
|
|
sg_mark_end(&sg[sg_size - 1]);
|
|
|
|
|
|
|
|
prv = sg;
|
|
|
|
} while (left);
|
|
|
|
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
|
|
|
/**
|
|
|
|
* sg_alloc_table - Allocate and initialize an sg table
|
|
|
|
* @table: The sg table header to use
|
|
|
|
* @nents: Number of entries in sg list
|
|
|
|
* @gfp_mask: GFP allocation mask
|
|
|
|
*
|
|
|
|
* Description:
|
|
|
|
* Allocate and initialize an sg table. If @nents@ is larger than
|
|
|
|
* SG_MAX_SINGLE_ALLOC a chained sg table will be setup.
|
|
|
|
*
|
|
|
|
**/
|
|
|
|
|
|
|
|
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;
|
|
|
|
}
|
|
|
|
|
2015-10-19 11:09:51 +00:00
|
|
|
/*
|
|
|
|
* Iterate pages in sg list.
|
|
|
|
*/
|
|
|
|
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;
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* NOTE: pgoffset is really a page index, not a byte offset.
|
|
|
|
*/
|
|
|
|
static inline void
|
|
|
|
_sg_iter_init(struct scatterlist *sgl, struct sg_page_iter *iter,
|
|
|
|
unsigned int nents, unsigned long pgoffset)
|
|
|
|
{
|
|
|
|
if (nents) {
|
|
|
|
/*
|
|
|
|
* Nominal case. Note subtract 1 from starting page index
|
|
|
|
* for initial _sg_iter_next() call.
|
|
|
|
*/
|
|
|
|
iter->sg = sgl;
|
|
|
|
iter->sg_pgoffset = pgoffset - 1;
|
|
|
|
iter->maxents = nents;
|
|
|
|
_sg_iter_next(iter);
|
|
|
|
} else {
|
|
|
|
/*
|
|
|
|
* Degenerate case
|
|
|
|
*/
|
|
|
|
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))
|
|
|
|
|
2011-03-21 09:58:24 +00:00
|
|
|
#define for_each_sg(sglist, sg, sgmax, _itr) \
|
|
|
|
for (_itr = 0, sg = (sglist); _itr < (sgmax); _itr++, sg = sg_next(sg))
|
|
|
|
|
|
|
|
#endif /* _LINUX_SCATTERLIST_H_ */
|