| Message ID | 150212398819.23722.8426106632424986011.stgit@djiang5-desk3.ch.intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Mon, Aug 7, 2017 at 9:39 AM, Dave Jiang <dave.jiang@intel.com> wrote: > This should provide support to unmap scatterlist with the > dmaengine_unmap_data. We will support only 1 scatterlist per > direction. The DMA addresses array has been overloaded for the > 2 or less entries DMA unmap data structure in order to store the > SG pointer(s). > > Signed-off-by: Dave Jiang <dave.jiang@intel.com> > --- > drivers/dma/dmaengine.c | 45 ++++++++++++++++++++++++++++++++++++--------- > include/linux/dmaengine.h | 22 ++++++++++++++++++++++ > 2 files changed, 58 insertions(+), 9 deletions(-) > > diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c > index d9a71f0..7d1f7ad 100644 > --- a/drivers/dma/dmaengine.c > +++ b/drivers/dma/dmaengine.c > @@ -1130,16 +1130,35 @@ static void dmaengine_unmap(struct kref *kref) > { > struct dmaengine_unmap_data *unmap = container_of(kref, typeof(*unmap), kref); > struct device *dev = unmap->dev; > - int cnt, i; > + int cnt, i, sg_nents; > + struct scatterlist *sg; > + > + sg_nents = dma_unmap_data_sg_to_nents(unmap, unmap->map_cnt); > + if (sg_nents) { > + i = 0; > + cnt = 1; > + dma_unmap_data_get_virt(unmap, sg, i); > + dma_unmap_sg(dev, sg, sg_nents, DMA_TO_DEVICE); > + } else { > + cnt = unmap->to_cnt; > + for (i = 0; i < cnt; i++) > + dma_unmap_page(dev, unmap->addr[i], unmap->len, > + DMA_TO_DEVICE); > + } > + > + sg_nents = dma_unmap_data_sg_from_nents(unmap, unmap->map_cnt); > + if (sg_nents) { > + dma_unmap_data_get_virt(unmap, sg, i); > + dma_unmap_sg(dev, sg, sg_nents, DMA_FROM_DEVICE); > + cnt++; > + i++; > + } else { > + cnt += unmap->from_cnt; > + for (; i < cnt; i++) > + dma_unmap_page(dev, unmap->addr[i], unmap->len, > + DMA_FROM_DEVICE); > + } > > - cnt = unmap->to_cnt; > - for (i = 0; i < cnt; i++) > - dma_unmap_page(dev, unmap->addr[i], unmap->len, > - DMA_TO_DEVICE); > - cnt += unmap->from_cnt; > - for (; i < cnt; i++) > - dma_unmap_page(dev, unmap->addr[i], unmap->len, > - DMA_FROM_DEVICE); > cnt += unmap->bidi_cnt; > for (; i < cnt; i++) { > if (unmap->addr[i] == 0) > @@ -1183,6 +1202,10 @@ static int __init dmaengine_init_unmap_pool(void) > size = sizeof(struct dmaengine_unmap_data) + > sizeof(dma_addr_t) * p->size; > > + /* add 2 more entries for SG nents overload */ > + if (i == 0) > + size += sizeof(dma_addr_t) * 2; > + > p->cache = kmem_cache_create(p->name, size, 0, > SLAB_HWCACHE_ALIGN, NULL); > if (!p->cache) > @@ -1209,6 +1232,10 @@ dmaengine_get_unmap_data(struct device *dev, int nr, gfp_t flags) > return NULL; > > memset(unmap, 0, sizeof(*unmap)); > + /* clear the overloaded sg nents entries */ > + if (nr < 3) > + memset(&unmap->addr[nr], 0, > + DMA_UNMAP_SG_ENTS * sizeof(dma_addr_t)); > kref_init(&unmap->kref); > unmap->dev = dev; > unmap->map_cnt = nr; > diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h > index fc25475..3a7fc68 100644 > --- a/include/linux/dmaengine.h > +++ b/include/linux/dmaengine.h > @@ -476,6 +476,28 @@ struct dmaengine_unmap_data { > dma_addr_t addr[0]; > }; > > +#define DMA_UNMAP_SG_ENTS 2 > +#define dma_unmap_data_sg_to_nents(x, n) x->addr[n] > +#define dma_unmap_data_sg_from_nents(x, n) x->addr[n+1] > + > +#if !defined(CONFIG_64BIT) && defined(CONFIG_PCI_BUS_ADDR_T_64BIT) > +/* 32bit CPU, 64bit DMA */ > +#define dma_unmap_data_set_virt(u, virt, idx) \ > + do {\ > + u32 tmp = (u32)virt; \ > + u->addr[idx] = tmp; \ > + } while (0); > + > +#define dma_unmap_data_get_virt(u, ptr, idx) \ > + do {\ > + u32 tmp = u->addr[idx]; \ > + ptr = (void *)tmp; \ > + } while (0); > +#else > +#define dma_unmap_data_set_virt(u, virt, idx) u->addr[idx] = (dma_addr_t)virt; > +#define dma_unmap_data_get_virt(u, ptr, idx) ptr = (void *)u->addr[idx] > +#endif I'm not keen on this cleverness, let's make scatterlist a first class citizen of dmaengine_unmap_data and union it with the address array. Ideally we could deprecate support for the dma_map_page() and dma_map_single() cases and rewrite all users to submit requests in terms of scatterlists. This would be nice step towards fixing the dmaengine operation type proliferation problem.
diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c index d9a71f0..7d1f7ad 100644 --- a/drivers/dma/dmaengine.c +++ b/drivers/dma/dmaengine.c @@ -1130,16 +1130,35 @@ static void dmaengine_unmap(struct kref *kref) { struct dmaengine_unmap_data *unmap = container_of(kref, typeof(*unmap), kref); struct device *dev = unmap->dev; - int cnt, i; + int cnt, i, sg_nents; + struct scatterlist *sg; + + sg_nents = dma_unmap_data_sg_to_nents(unmap, unmap->map_cnt); + if (sg_nents) { + i = 0; + cnt = 1; + dma_unmap_data_get_virt(unmap, sg, i); + dma_unmap_sg(dev, sg, sg_nents, DMA_TO_DEVICE); + } else { + cnt = unmap->to_cnt; + for (i = 0; i < cnt; i++) + dma_unmap_page(dev, unmap->addr[i], unmap->len, + DMA_TO_DEVICE); + } + + sg_nents = dma_unmap_data_sg_from_nents(unmap, unmap->map_cnt); + if (sg_nents) { + dma_unmap_data_get_virt(unmap, sg, i); + dma_unmap_sg(dev, sg, sg_nents, DMA_FROM_DEVICE); + cnt++; + i++; + } else { + cnt += unmap->from_cnt; + for (; i < cnt; i++) + dma_unmap_page(dev, unmap->addr[i], unmap->len, + DMA_FROM_DEVICE); + } - cnt = unmap->to_cnt; - for (i = 0; i < cnt; i++) - dma_unmap_page(dev, unmap->addr[i], unmap->len, - DMA_TO_DEVICE); - cnt += unmap->from_cnt; - for (; i < cnt; i++) - dma_unmap_page(dev, unmap->addr[i], unmap->len, - DMA_FROM_DEVICE); cnt += unmap->bidi_cnt; for (; i < cnt; i++) { if (unmap->addr[i] == 0) @@ -1183,6 +1202,10 @@ static int __init dmaengine_init_unmap_pool(void) size = sizeof(struct dmaengine_unmap_data) + sizeof(dma_addr_t) * p->size; + /* add 2 more entries for SG nents overload */ + if (i == 0) + size += sizeof(dma_addr_t) * 2; + p->cache = kmem_cache_create(p->name, size, 0, SLAB_HWCACHE_ALIGN, NULL); if (!p->cache) @@ -1209,6 +1232,10 @@ dmaengine_get_unmap_data(struct device *dev, int nr, gfp_t flags) return NULL; memset(unmap, 0, sizeof(*unmap)); + /* clear the overloaded sg nents entries */ + if (nr < 3) + memset(&unmap->addr[nr], 0, + DMA_UNMAP_SG_ENTS * sizeof(dma_addr_t)); kref_init(&unmap->kref); unmap->dev = dev; unmap->map_cnt = nr; diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h index fc25475..3a7fc68 100644 --- a/include/linux/dmaengine.h +++ b/include/linux/dmaengine.h @@ -476,6 +476,28 @@ struct dmaengine_unmap_data { dma_addr_t addr[0]; }; +#define DMA_UNMAP_SG_ENTS 2 +#define dma_unmap_data_sg_to_nents(x, n) x->addr[n] +#define dma_unmap_data_sg_from_nents(x, n) x->addr[n+1] + +#if !defined(CONFIG_64BIT) && defined(CONFIG_PCI_BUS_ADDR_T_64BIT) +/* 32bit CPU, 64bit DMA */ +#define dma_unmap_data_set_virt(u, virt, idx) \ + do {\ + u32 tmp = (u32)virt; \ + u->addr[idx] = tmp; \ + } while (0); + +#define dma_unmap_data_get_virt(u, ptr, idx) \ + do {\ + u32 tmp = u->addr[idx]; \ + ptr = (void *)tmp; \ + } while (0); +#else +#define dma_unmap_data_set_virt(u, virt, idx) u->addr[idx] = (dma_addr_t)virt; +#define dma_unmap_data_get_virt(u, ptr, idx) ptr = (void *)u->addr[idx] +#endif + /** * struct dma_async_tx_descriptor - async transaction descriptor * ---dma generic offload fields---
This should provide support to unmap scatterlist with the dmaengine_unmap_data. We will support only 1 scatterlist per direction. The DMA addresses array has been overloaded for the 2 or less entries DMA unmap data structure in order to store the SG pointer(s). Signed-off-by: Dave Jiang <dave.jiang@intel.com> --- drivers/dma/dmaengine.c | 45 ++++++++++++++++++++++++++++++++++++--------- include/linux/dmaengine.h | 22 ++++++++++++++++++++++ 2 files changed, 58 insertions(+), 9 deletions(-)