diff options
Diffstat (limited to 'lib/scatterlist.c')
| -rw-r--r-- | lib/scatterlist.c | 35 |
1 files changed, 27 insertions, 8 deletions
diff --git a/lib/scatterlist.c b/lib/scatterlist.c index fadae774a20c..3675452b23ca 100644 --- a/lib/scatterlist.c +++ b/lib/scatterlist.c @@ -39,6 +39,25 @@ struct scatterlist *sg_next(struct scatterlist *sg) EXPORT_SYMBOL(sg_next); /** + * sg_nents - return total count of entries in scatterlist + * @sg: The scatterlist + * + * Description: + * Allows to know how many entries are in sg, taking into acount + * chaining as well + * + **/ +int sg_nents(struct scatterlist *sg) +{ + int nents; + for (nents = 0; sg; sg = sg_next(sg)) + nents++; + return nents; +} +EXPORT_SYMBOL(sg_nents); + + +/** * sg_last - return the last scatterlist entry in a list * @sgl: First entry in the scatterlist * @nents: Number of entries in the scatterlist @@ -404,14 +423,13 @@ EXPORT_SYMBOL(sg_miter_start); * @miter: sg mapping iter to proceed * * Description: - * Proceeds @miter@ to the next mapping. @miter@ should have been - * started using sg_miter_start(). On successful return, - * @miter@->page, @miter@->addr and @miter@->length point to the - * current mapping. + * Proceeds @miter to the next mapping. @miter should have been started + * using sg_miter_start(). On successful return, @miter->page, + * @miter->addr and @miter->length point to the current mapping. * * Context: - * IRQ disabled if SG_MITER_ATOMIC. IRQ must stay disabled till - * @miter@ is stopped. May sleep if !SG_MITER_ATOMIC. + * Preemption disabled if SG_MITER_ATOMIC. Preemption must stay disabled + * till @miter is stopped. May sleep if !SG_MITER_ATOMIC. * * Returns: * true if @miter contains the next mapping. false if end of sg @@ -465,7 +483,8 @@ EXPORT_SYMBOL(sg_miter_next); * resources (kmap) need to be released during iteration. * * Context: - * IRQ disabled if the SG_MITER_ATOMIC is set. Don't care otherwise. + * Preemption disabled if the SG_MITER_ATOMIC is set. Don't care + * otherwise. */ void sg_miter_stop(struct sg_mapping_iter *miter) { @@ -479,7 +498,7 @@ void sg_miter_stop(struct sg_mapping_iter *miter) flush_kernel_dcache_page(miter->page); if (miter->__flags & SG_MITER_ATOMIC) { - WARN_ON(!irqs_disabled()); + WARN_ON_ONCE(preemptible()); kunmap_atomic(miter->addr); } else kunmap(miter->page); |