diff options
| -rw-r--r-- | include/linux/scatterlist.h | 2 | ||||
| -rw-r--r-- | lib/scatterlist.c | 16 |
2 files changed, 14 insertions, 4 deletions
diff --git a/include/linux/scatterlist.h b/include/linux/scatterlist.h index e5996984ddd..9aaf5bfdad1 100644 --- a/include/linux/scatterlist.h +++ b/include/linux/scatterlist.h @@ -242,6 +242,8 @@ size_t sg_copy_to_buffer(struct scatterlist *sgl, unsigned int nents, */ #define SG_MITER_ATOMIC (1 << 0) /* use kmap_atomic */ +#define SG_MITER_TO_SG (1 << 1) /* flush back to phys on unmap */ +#define SG_MITER_FROM_SG (1 << 2) /* nop */ struct sg_mapping_iter { /* the following three fields can be accessed directly */ diff --git a/lib/scatterlist.c b/lib/scatterlist.c index a295e404e90..0d475d8167b 100644 --- a/lib/scatterlist.c +++ b/lib/scatterlist.c @@ -314,6 +314,7 @@ void sg_miter_start(struct sg_mapping_iter *miter, struct scatterlist *sgl, miter->__sg = sgl; miter->__nents = nents; miter->__offset = 0; + WARN_ON(!(flags & (SG_MITER_TO_SG | SG_MITER_FROM_SG))); miter->__flags = flags; } EXPORT_SYMBOL(sg_miter_start); @@ -394,6 +395,9 @@ void sg_miter_stop(struct sg_mapping_iter *miter) if (miter->addr) { miter->__offset += miter->consumed; + if (miter->__flags & SG_MITER_TO_SG) + flush_kernel_dcache_page(miter->page); + if (miter->__flags & SG_MITER_ATOMIC) { WARN_ON(!irqs_disabled()); kunmap_atomic(miter->addr, KM_BIO_SRC_IRQ); @@ -426,8 +430,14 @@ static size_t sg_copy_buffer(struct scatterlist *sgl, unsigned int nents, unsigned int offset = 0; struct sg_mapping_iter miter; unsigned long flags; + unsigned int sg_flags = SG_MITER_ATOMIC; + + if (to_buffer) + sg_flags |= SG_MITER_FROM_SG; + else + sg_flags |= SG_MITER_TO_SG; - sg_miter_start(&miter, sgl, nents, SG_MITER_ATOMIC); + sg_miter_start(&miter, sgl, nents, sg_flags); local_irq_save(flags); @@ -438,10 +448,8 @@ static size_t sg_copy_buffer(struct scatterlist *sgl, unsigned int nents, if (to_buffer) memcpy(buf + offset, miter.addr, len); - else { + else memcpy(miter.addr, buf + offset, len); - flush_kernel_dcache_page(miter.page); - } offset += len; } |