* __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
- * @skip_first_chunk: don't free the (preallocated) first scatterlist chunk
+ * @nents_first_chunk: Number of entries int the (preallocated) first
+ * scatterlist chunk, 0 means no such preallocated first chunk
* @free_fn: Free function
*
* Description:
*
**/
void __sg_free_table(struct sg_table *table, unsigned int max_ents,
- bool skip_first_chunk, sg_free_fn *free_fn)
+ unsigned int nents_first_chunk, sg_free_fn *free_fn)
{
struct scatterlist *sgl, *next;
+ unsigned curr_max_ents = nents_first_chunk ?: max_ents;
if (unlikely(!table->sgl))
return;
* sg_size is then one less than alloc size, since the last
* element is the chain pointer.
*/
- if (alloc_size > max_ents) {
- next = sg_chain_ptr(&sgl[max_ents - 1]);
- alloc_size = max_ents;
+ if (alloc_size > curr_max_ents) {
+ next = sg_chain_ptr(&sgl[curr_max_ents - 1]);
+ alloc_size = curr_max_ents;
sg_size = alloc_size - 1;
} else {
sg_size = alloc_size;
}
table->orig_nents -= sg_size;
- if (skip_first_chunk)
- skip_first_chunk = false;
+ if (nents_first_chunk)
+ nents_first_chunk = 0;
else
free_fn(sgl, alloc_size);
sgl = next;
+ curr_max_ents = max_ents;
}
table->sgl = NULL;
* @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
+ * @nents_first_chunk: Number of entries int the (preallocated) first
+ * scatterlist chunk, 0 means no such preallocated chunk provided by user
* @gfp_mask: GFP allocation mask
* @alloc_fn: Allocator to use
*
**/
int __sg_alloc_table(struct sg_table *table, unsigned int nents,
unsigned int max_ents, struct scatterlist *first_chunk,
- gfp_t gfp_mask, sg_alloc_fn *alloc_fn)
+ unsigned int nents_first_chunk, gfp_t gfp_mask,
+ sg_alloc_fn *alloc_fn)
{
struct scatterlist *sg, *prv;
unsigned int left;
+ unsigned curr_max_ents = nents_first_chunk ?: max_ents;
+ unsigned prv_max_ents;
memset(table, 0, sizeof(*table));
do {
unsigned int sg_size, alloc_size = left;
- if (alloc_size > max_ents) {
- alloc_size = max_ents;
+ if (alloc_size > curr_max_ents) {
+ alloc_size = curr_max_ents;
sg_size = alloc_size - 1;
} else
sg_size = alloc_size;
* If this is not the first mapping, chain previous part.
*/
if (prv)
- sg_chain(prv, max_ents, sg);
+ sg_chain(prv, prv_max_ents, sg);
else
table->sgl = sg;
sg_mark_end(&sg[sg_size - 1]);
prv = sg;
+ prv_max_ents = curr_max_ents;
+ curr_max_ents = max_ents;
} while (left);
return 0;
int ret;
ret = __sg_alloc_table(table, nents, SG_MAX_SINGLE_ALLOC,
- NULL, gfp_mask, sg_kmalloc);
+ NULL, 0, gfp_mask, sg_kmalloc);
if (unlikely(ret))
- __sg_free_table(table, SG_MAX_SINGLE_ALLOC, false, sg_kfree);
+ __sg_free_table(table, SG_MAX_SINGLE_ALLOC, 0, sg_kfree);
return ret;
}
{
if (!miter->__remaining) {
struct scatterlist *sg;
- unsigned long pgoffset;
if (!__sg_page_iter_next(&miter->piter))
return false;
sg = miter->piter.sg;
- pgoffset = miter->piter.sg_pgoffset;
- miter->__offset = pgoffset ? 0 : sg->offset;
+ miter->__offset = miter->piter.sg_pgoffset ? 0 : sg->offset;
+ miter->piter.sg_pgoffset += miter->__offset >> PAGE_SHIFT;
+ miter->__offset &= PAGE_SIZE - 1;
miter->__remaining = sg->offset + sg->length -
- (pgoffset << PAGE_SHIFT) - miter->__offset;
+ (miter->piter.sg_pgoffset << PAGE_SHIFT) -
+ miter->__offset;
miter->__remaining = min_t(unsigned long, miter->__remaining,
PAGE_SIZE - miter->__offset);
}