| Message ID | 20190514140515.35566-2-christian.koenig@amd.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [1/2] dma-buf: start caching of sg_table objects v2 | expand |
On Tue, May 14, 2019 at 04:05:14PM +0200, Christian König wrote: > To allow a smooth transition from pinning buffer objects to dynamic > invalidation we first start to cache the sg_table for an attachment. > > v2: keep closer to the DRM implementation > > Signed-off-by: Christian König <christian.koenig@amd.com> i915 doesn't use the prime helpers, so this would be a change for us. Not sure that matters. Since we can't use this as an easy way out of the locking problem around reservation_object I'm not sure how useful it is to move this ahead. At least until we have a clearer picture on how we plan to roll out the dynamic dma-buf stuff. Once we have a bit more clarity there I'm all for merging prep work, but as-is I'd be cautious ... This stuff is a lot more tricky than it seems at first :-/ -Daniel > --- > drivers/dma-buf/dma-buf.c | 27 +++++++++++++++++++++++++-- > include/linux/dma-buf.h | 13 +++++++++++++ > 2 files changed, 38 insertions(+), 2 deletions(-) > > diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c > index 7c858020d14b..a2d34c6b80a5 100644 > --- a/drivers/dma-buf/dma-buf.c > +++ b/drivers/dma-buf/dma-buf.c > @@ -573,6 +573,7 @@ struct dma_buf_attachment *dma_buf_attach(struct dma_buf *dmabuf, > list_add(&attach->node, &dmabuf->attachments); > > mutex_unlock(&dmabuf->lock); > + > return attach; > > err_attach: > @@ -595,6 +596,9 @@ void dma_buf_detach(struct dma_buf *dmabuf, struct dma_buf_attachment *attach) > if (WARN_ON(!dmabuf || !attach)) > return; > > + if (attach->sgt) > + dmabuf->ops->unmap_dma_buf(attach, attach->sgt, attach->dir); > + > mutex_lock(&dmabuf->lock); > list_del(&attach->node); > if (dmabuf->ops->detach) > @@ -630,10 +634,27 @@ struct sg_table *dma_buf_map_attachment(struct dma_buf_attachment *attach, > if (WARN_ON(!attach || !attach->dmabuf)) > return ERR_PTR(-EINVAL); > > + if (attach->sgt) { > + /* > + * Two mappings with different directions for the same > + * attachment are not allowed. > + */ > + if (attach->dir != direction && > + attach->dir != DMA_BIDIRECTIONAL) > + return ERR_PTR(-EBUSY); > + > + return attach->sgt; > + } > + > sg_table = attach->dmabuf->ops->map_dma_buf(attach, direction); > if (!sg_table) > sg_table = ERR_PTR(-ENOMEM); > > + if (!IS_ERR(sg_table) && attach->dmabuf->ops->cache_sgt_mapping) { > + attach->sgt = sg_table; > + attach->dir = direction; > + } > + > return sg_table; > } > EXPORT_SYMBOL_GPL(dma_buf_map_attachment); > @@ -657,8 +678,10 @@ void dma_buf_unmap_attachment(struct dma_buf_attachment *attach, > if (WARN_ON(!attach || !attach->dmabuf || !sg_table)) > return; > > - attach->dmabuf->ops->unmap_dma_buf(attach, sg_table, > - direction); > + if (attach->sgt == sg_table) > + return; > + > + attach->dmabuf->ops->unmap_dma_buf(attach, sg_table, direction); > } > EXPORT_SYMBOL_GPL(dma_buf_unmap_attachment); > > diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h > index 58725f890b5b..45b9767e67ec 100644 > --- a/include/linux/dma-buf.h > +++ b/include/linux/dma-buf.h > @@ -51,6 +51,15 @@ struct dma_buf_attachment; > * @vunmap: [optional] unmaps a vmap from the buffer > */ > struct dma_buf_ops { > + /** > + * @cache_sgt_mapping: > + * > + * If true the framework will cache the first mapping made for each > + * attachment. This avoids creating mappings for attachments multiple > + * times. > + */ > + bool cache_sgt_mapping; > + > /** > * @attach: > * > @@ -307,6 +316,8 @@ struct dma_buf { > * @dmabuf: buffer for this attachment. > * @dev: device attached to the buffer. > * @node: list of dma_buf_attachment. > + * @sgt: cached mapping. > + * @dir: direction of cached mapping. > * @priv: exporter specific attachment data. > * > * This structure holds the attachment information between the dma_buf buffer > @@ -322,6 +333,8 @@ struct dma_buf_attachment { > struct dma_buf *dmabuf; > struct device *dev; > struct list_head node; > + struct sg_table *sgt; > + enum dma_data_direction dir; > void *priv; > }; > > -- > 2.17.1 >
Am 15.05.19 um 10:58 schrieb Daniel Vetter: > On Tue, May 14, 2019 at 04:05:14PM +0200, Christian König wrote: >> To allow a smooth transition from pinning buffer objects to dynamic >> invalidation we first start to cache the sg_table for an attachment. >> >> v2: keep closer to the DRM implementation >> >> Signed-off-by: Christian König <christian.koenig@amd.com> > i915 doesn't use the prime helpers, so this would be a change for us. Not a problem at all, see below. I've added an cache_sgt_mapping member into the dma_buf_ops structure. Only when this member is true the functionality is enabled. So I'm just moving code around in those two patches and no functional change at all. Regards, Christian. > Not > sure that matters. Since we can't use this as an easy way out of the > locking problem around reservation_object I'm not sure how useful it is to > move this ahead. At least until we have a clearer picture on how we plan > to roll out the dynamic dma-buf stuff. Once we have a bit more clarity > there I'm all for merging prep work, but as-is I'd be cautious ... This > stuff is a lot more tricky than it seems at first :-/ > -Daniel >> --- >> drivers/dma-buf/dma-buf.c | 27 +++++++++++++++++++++++++-- >> include/linux/dma-buf.h | 13 +++++++++++++ >> 2 files changed, 38 insertions(+), 2 deletions(-) >> >> diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c >> index 7c858020d14b..a2d34c6b80a5 100644 >> --- a/drivers/dma-buf/dma-buf.c >> +++ b/drivers/dma-buf/dma-buf.c >> @@ -573,6 +573,7 @@ struct dma_buf_attachment *dma_buf_attach(struct dma_buf *dmabuf, >> list_add(&attach->node, &dmabuf->attachments); >> >> mutex_unlock(&dmabuf->lock); >> + >> return attach; >> >> err_attach: >> @@ -595,6 +596,9 @@ void dma_buf_detach(struct dma_buf *dmabuf, struct dma_buf_attachment *attach) >> if (WARN_ON(!dmabuf || !attach)) >> return; >> >> + if (attach->sgt) >> + dmabuf->ops->unmap_dma_buf(attach, attach->sgt, attach->dir); >> + >> mutex_lock(&dmabuf->lock); >> list_del(&attach->node); >> if (dmabuf->ops->detach) >> @@ -630,10 +634,27 @@ struct sg_table *dma_buf_map_attachment(struct dma_buf_attachment *attach, >> if (WARN_ON(!attach || !attach->dmabuf)) >> return ERR_PTR(-EINVAL); >> >> + if (attach->sgt) { >> + /* >> + * Two mappings with different directions for the same >> + * attachment are not allowed. >> + */ >> + if (attach->dir != direction && >> + attach->dir != DMA_BIDIRECTIONAL) >> + return ERR_PTR(-EBUSY); >> + >> + return attach->sgt; >> + } >> + >> sg_table = attach->dmabuf->ops->map_dma_buf(attach, direction); >> if (!sg_table) >> sg_table = ERR_PTR(-ENOMEM); >> >> + if (!IS_ERR(sg_table) && attach->dmabuf->ops->cache_sgt_mapping) { >> + attach->sgt = sg_table; >> + attach->dir = direction; >> + } >> + >> return sg_table; >> } >> EXPORT_SYMBOL_GPL(dma_buf_map_attachment); >> @@ -657,8 +678,10 @@ void dma_buf_unmap_attachment(struct dma_buf_attachment *attach, >> if (WARN_ON(!attach || !attach->dmabuf || !sg_table)) >> return; >> >> - attach->dmabuf->ops->unmap_dma_buf(attach, sg_table, >> - direction); >> + if (attach->sgt == sg_table) >> + return; >> + >> + attach->dmabuf->ops->unmap_dma_buf(attach, sg_table, direction); >> } >> EXPORT_SYMBOL_GPL(dma_buf_unmap_attachment); >> >> diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h >> index 58725f890b5b..45b9767e67ec 100644 >> --- a/include/linux/dma-buf.h >> +++ b/include/linux/dma-buf.h >> @@ -51,6 +51,15 @@ struct dma_buf_attachment; >> * @vunmap: [optional] unmaps a vmap from the buffer >> */ >> struct dma_buf_ops { >> + /** >> + * @cache_sgt_mapping: >> + * >> + * If true the framework will cache the first mapping made for each >> + * attachment. This avoids creating mappings for attachments multiple >> + * times. >> + */ >> + bool cache_sgt_mapping; >> + >> /** >> * @attach: >> * >> @@ -307,6 +316,8 @@ struct dma_buf { >> * @dmabuf: buffer for this attachment. >> * @dev: device attached to the buffer. >> * @node: list of dma_buf_attachment. >> + * @sgt: cached mapping. >> + * @dir: direction of cached mapping. >> * @priv: exporter specific attachment data. >> * >> * This structure holds the attachment information between the dma_buf buffer >> @@ -322,6 +333,8 @@ struct dma_buf_attachment { >> struct dma_buf *dmabuf; >> struct device *dev; >> struct list_head node; >> + struct sg_table *sgt; >> + enum dma_data_direction dir; >> void *priv; >> }; >> >> -- >> 2.17.1 >>
On Wed, May 15, 2019 at 11:25 AM Christian König <ckoenig.leichtzumerken@gmail.com> wrote: > > Am 15.05.19 um 10:58 schrieb Daniel Vetter: > > On Tue, May 14, 2019 at 04:05:14PM +0200, Christian König wrote: > >> To allow a smooth transition from pinning buffer objects to dynamic > >> invalidation we first start to cache the sg_table for an attachment. > >> > >> v2: keep closer to the DRM implementation > >> > >> Signed-off-by: Christian König <christian.koenig@amd.com> > > i915 doesn't use the prime helpers, so this would be a change for us. > > Not a problem at all, see below. I've added an cache_sgt_mapping member > into the dma_buf_ops structure. Only when this member is true the > functionality is enabled. Hm right I missed that. > So I'm just moving code around in those two patches and no functional > change at all. Still not sure. I'll look at your latest dma-buf series to see how it all fits together. -Daniel > > Regards, > Christian. > > > Not > > sure that matters. Since we can't use this as an easy way out of the > > locking problem around reservation_object I'm not sure how useful it is to > > move this ahead. At least until we have a clearer picture on how we plan > > to roll out the dynamic dma-buf stuff. Once we have a bit more clarity > > there I'm all for merging prep work, but as-is I'd be cautious ... This > > stuff is a lot more tricky than it seems at first :-/ > > -Daniel > >> --- > >> drivers/dma-buf/dma-buf.c | 27 +++++++++++++++++++++++++-- > >> include/linux/dma-buf.h | 13 +++++++++++++ > >> 2 files changed, 38 insertions(+), 2 deletions(-) > >> > >> diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c > >> index 7c858020d14b..a2d34c6b80a5 100644 > >> --- a/drivers/dma-buf/dma-buf.c > >> +++ b/drivers/dma-buf/dma-buf.c > >> @@ -573,6 +573,7 @@ struct dma_buf_attachment *dma_buf_attach(struct dma_buf *dmabuf, > >> list_add(&attach->node, &dmabuf->attachments); > >> > >> mutex_unlock(&dmabuf->lock); > >> + > >> return attach; > >> > >> err_attach: > >> @@ -595,6 +596,9 @@ void dma_buf_detach(struct dma_buf *dmabuf, struct dma_buf_attachment *attach) > >> if (WARN_ON(!dmabuf || !attach)) > >> return; > >> > >> + if (attach->sgt) > >> + dmabuf->ops->unmap_dma_buf(attach, attach->sgt, attach->dir); > >> + > >> mutex_lock(&dmabuf->lock); > >> list_del(&attach->node); > >> if (dmabuf->ops->detach) > >> @@ -630,10 +634,27 @@ struct sg_table *dma_buf_map_attachment(struct dma_buf_attachment *attach, > >> if (WARN_ON(!attach || !attach->dmabuf)) > >> return ERR_PTR(-EINVAL); > >> > >> + if (attach->sgt) { > >> + /* > >> + * Two mappings with different directions for the same > >> + * attachment are not allowed. > >> + */ > >> + if (attach->dir != direction && > >> + attach->dir != DMA_BIDIRECTIONAL) > >> + return ERR_PTR(-EBUSY); > >> + > >> + return attach->sgt; > >> + } > >> + > >> sg_table = attach->dmabuf->ops->map_dma_buf(attach, direction); > >> if (!sg_table) > >> sg_table = ERR_PTR(-ENOMEM); > >> > >> + if (!IS_ERR(sg_table) && attach->dmabuf->ops->cache_sgt_mapping) { > >> + attach->sgt = sg_table; > >> + attach->dir = direction; > >> + } > >> + > >> return sg_table; > >> } > >> EXPORT_SYMBOL_GPL(dma_buf_map_attachment); > >> @@ -657,8 +678,10 @@ void dma_buf_unmap_attachment(struct dma_buf_attachment *attach, > >> if (WARN_ON(!attach || !attach->dmabuf || !sg_table)) > >> return; > >> > >> - attach->dmabuf->ops->unmap_dma_buf(attach, sg_table, > >> - direction); > >> + if (attach->sgt == sg_table) > >> + return; > >> + > >> + attach->dmabuf->ops->unmap_dma_buf(attach, sg_table, direction); > >> } > >> EXPORT_SYMBOL_GPL(dma_buf_unmap_attachment); > >> > >> diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h > >> index 58725f890b5b..45b9767e67ec 100644 > >> --- a/include/linux/dma-buf.h > >> +++ b/include/linux/dma-buf.h > >> @@ -51,6 +51,15 @@ struct dma_buf_attachment; > >> * @vunmap: [optional] unmaps a vmap from the buffer > >> */ > >> struct dma_buf_ops { > >> + /** > >> + * @cache_sgt_mapping: > >> + * > >> + * If true the framework will cache the first mapping made for each > >> + * attachment. This avoids creating mappings for attachments multiple > >> + * times. > >> + */ > >> + bool cache_sgt_mapping; > >> + > >> /** > >> * @attach: > >> * > >> @@ -307,6 +316,8 @@ struct dma_buf { > >> * @dmabuf: buffer for this attachment. > >> * @dev: device attached to the buffer. > >> * @node: list of dma_buf_attachment. > >> + * @sgt: cached mapping. > >> + * @dir: direction of cached mapping. > >> * @priv: exporter specific attachment data. > >> * > >> * This structure holds the attachment information between the dma_buf buffer > >> @@ -322,6 +333,8 @@ struct dma_buf_attachment { > >> struct dma_buf *dmabuf; > >> struct device *dev; > >> struct list_head node; > >> + struct sg_table *sgt; > >> + enum dma_data_direction dir; > >> void *priv; > >> }; > >> > >> -- > >> 2.17.1 > >> > -- Daniel Vetter Software Engineer, Intel Corporation +41 (0) 79 365 57 48 - http://blog.ffwll.ch
On Thu, May 16, 2019 at 08:26:36AM +0200, Daniel Vetter wrote: > On Wed, May 15, 2019 at 11:25 AM Christian König > <ckoenig.leichtzumerken@gmail.com> wrote: > > > > Am 15.05.19 um 10:58 schrieb Daniel Vetter: > > > On Tue, May 14, 2019 at 04:05:14PM +0200, Christian König wrote: > > >> To allow a smooth transition from pinning buffer objects to dynamic > > >> invalidation we first start to cache the sg_table for an attachment. > > >> > > >> v2: keep closer to the DRM implementation > > >> > > >> Signed-off-by: Christian König <christian.koenig@amd.com> > > > i915 doesn't use the prime helpers, so this would be a change for us. > > > > Not a problem at all, see below. I've added an cache_sgt_mapping member > > into the dma_buf_ops structure. Only when this member is true the > > functionality is enabled. > > Hm right I missed that. > > > So I'm just moving code around in those two patches and no functional > > change at all. > > Still not sure. I'll look at your latest dma-buf series to see how it > all fits together. Ok I'm still procrastinating on that one, but I guess either way we need some caching or another in dma-buf.c, and this series here at least looks like it's moving in that direction. On both patches Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> btw might be good to throw this at intel-gfx-trybot too, just to see whether anything is amiss. I think we've beaten down all the -rc1 regressions now. -Daniel > -Daniel > > > > > Regards, > > Christian. > > > > > Not > > > sure that matters. Since we can't use this as an easy way out of the > > > locking problem around reservation_object I'm not sure how useful it is to > > > move this ahead. At least until we have a clearer picture on how we plan > > > to roll out the dynamic dma-buf stuff. Once we have a bit more clarity > > > there I'm all for merging prep work, but as-is I'd be cautious ... This > > > stuff is a lot more tricky than it seems at first :-/ > > > -Daniel > > >> --- > > >> drivers/dma-buf/dma-buf.c | 27 +++++++++++++++++++++++++-- > > >> include/linux/dma-buf.h | 13 +++++++++++++ > > >> 2 files changed, 38 insertions(+), 2 deletions(-) > > >> > > >> diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c > > >> index 7c858020d14b..a2d34c6b80a5 100644 > > >> --- a/drivers/dma-buf/dma-buf.c > > >> +++ b/drivers/dma-buf/dma-buf.c > > >> @@ -573,6 +573,7 @@ struct dma_buf_attachment *dma_buf_attach(struct dma_buf *dmabuf, > > >> list_add(&attach->node, &dmabuf->attachments); > > >> > > >> mutex_unlock(&dmabuf->lock); > > >> + > > >> return attach; > > >> > > >> err_attach: > > >> @@ -595,6 +596,9 @@ void dma_buf_detach(struct dma_buf *dmabuf, struct dma_buf_attachment *attach) > > >> if (WARN_ON(!dmabuf || !attach)) > > >> return; > > >> > > >> + if (attach->sgt) > > >> + dmabuf->ops->unmap_dma_buf(attach, attach->sgt, attach->dir); > > >> + > > >> mutex_lock(&dmabuf->lock); > > >> list_del(&attach->node); > > >> if (dmabuf->ops->detach) > > >> @@ -630,10 +634,27 @@ struct sg_table *dma_buf_map_attachment(struct dma_buf_attachment *attach, > > >> if (WARN_ON(!attach || !attach->dmabuf)) > > >> return ERR_PTR(-EINVAL); > > >> > > >> + if (attach->sgt) { > > >> + /* > > >> + * Two mappings with different directions for the same > > >> + * attachment are not allowed. > > >> + */ > > >> + if (attach->dir != direction && > > >> + attach->dir != DMA_BIDIRECTIONAL) > > >> + return ERR_PTR(-EBUSY); > > >> + > > >> + return attach->sgt; > > >> + } > > >> + > > >> sg_table = attach->dmabuf->ops->map_dma_buf(attach, direction); > > >> if (!sg_table) > > >> sg_table = ERR_PTR(-ENOMEM); > > >> > > >> + if (!IS_ERR(sg_table) && attach->dmabuf->ops->cache_sgt_mapping) { > > >> + attach->sgt = sg_table; > > >> + attach->dir = direction; > > >> + } > > >> + > > >> return sg_table; > > >> } > > >> EXPORT_SYMBOL_GPL(dma_buf_map_attachment); > > >> @@ -657,8 +678,10 @@ void dma_buf_unmap_attachment(struct dma_buf_attachment *attach, > > >> if (WARN_ON(!attach || !attach->dmabuf || !sg_table)) > > >> return; > > >> > > >> - attach->dmabuf->ops->unmap_dma_buf(attach, sg_table, > > >> - direction); > > >> + if (attach->sgt == sg_table) > > >> + return; > > >> + > > >> + attach->dmabuf->ops->unmap_dma_buf(attach, sg_table, direction); > > >> } > > >> EXPORT_SYMBOL_GPL(dma_buf_unmap_attachment); > > >> > > >> diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h > > >> index 58725f890b5b..45b9767e67ec 100644 > > >> --- a/include/linux/dma-buf.h > > >> +++ b/include/linux/dma-buf.h > > >> @@ -51,6 +51,15 @@ struct dma_buf_attachment; > > >> * @vunmap: [optional] unmaps a vmap from the buffer > > >> */ > > >> struct dma_buf_ops { > > >> + /** > > >> + * @cache_sgt_mapping: > > >> + * > > >> + * If true the framework will cache the first mapping made for each > > >> + * attachment. This avoids creating mappings for attachments multiple > > >> + * times. > > >> + */ > > >> + bool cache_sgt_mapping; > > >> + > > >> /** > > >> * @attach: > > >> * > > >> @@ -307,6 +316,8 @@ struct dma_buf { > > >> * @dmabuf: buffer for this attachment. > > >> * @dev: device attached to the buffer. > > >> * @node: list of dma_buf_attachment. > > >> + * @sgt: cached mapping. > > >> + * @dir: direction of cached mapping. > > >> * @priv: exporter specific attachment data. > > >> * > > >> * This structure holds the attachment information between the dma_buf buffer > > >> @@ -322,6 +333,8 @@ struct dma_buf_attachment { > > >> struct dma_buf *dmabuf; > > >> struct device *dev; > > >> struct list_head node; > > >> + struct sg_table *sgt; > > >> + enum dma_data_direction dir; > > >> void *priv; > > >> }; > > >> > > >> -- > > >> 2.17.1 > > >> > > > > > -- > Daniel Vetter > Software Engineer, Intel Corporation > +41 (0) 79 365 57 48 - http://blog.ffwll.ch
diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c index 7c858020d14b..a2d34c6b80a5 100644 --- a/drivers/dma-buf/dma-buf.c +++ b/drivers/dma-buf/dma-buf.c @@ -573,6 +573,7 @@ struct dma_buf_attachment *dma_buf_attach(struct dma_buf *dmabuf, list_add(&attach->node, &dmabuf->attachments); mutex_unlock(&dmabuf->lock); + return attach; err_attach: @@ -595,6 +596,9 @@ void dma_buf_detach(struct dma_buf *dmabuf, struct dma_buf_attachment *attach) if (WARN_ON(!dmabuf || !attach)) return; + if (attach->sgt) + dmabuf->ops->unmap_dma_buf(attach, attach->sgt, attach->dir); + mutex_lock(&dmabuf->lock); list_del(&attach->node); if (dmabuf->ops->detach) @@ -630,10 +634,27 @@ struct sg_table *dma_buf_map_attachment(struct dma_buf_attachment *attach, if (WARN_ON(!attach || !attach->dmabuf)) return ERR_PTR(-EINVAL); + if (attach->sgt) { + /* + * Two mappings with different directions for the same + * attachment are not allowed. + */ + if (attach->dir != direction && + attach->dir != DMA_BIDIRECTIONAL) + return ERR_PTR(-EBUSY); + + return attach->sgt; + } + sg_table = attach->dmabuf->ops->map_dma_buf(attach, direction); if (!sg_table) sg_table = ERR_PTR(-ENOMEM); + if (!IS_ERR(sg_table) && attach->dmabuf->ops->cache_sgt_mapping) { + attach->sgt = sg_table; + attach->dir = direction; + } + return sg_table; } EXPORT_SYMBOL_GPL(dma_buf_map_attachment); @@ -657,8 +678,10 @@ void dma_buf_unmap_attachment(struct dma_buf_attachment *attach, if (WARN_ON(!attach || !attach->dmabuf || !sg_table)) return; - attach->dmabuf->ops->unmap_dma_buf(attach, sg_table, - direction); + if (attach->sgt == sg_table) + return; + + attach->dmabuf->ops->unmap_dma_buf(attach, sg_table, direction); } EXPORT_SYMBOL_GPL(dma_buf_unmap_attachment); diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h index 58725f890b5b..45b9767e67ec 100644 --- a/include/linux/dma-buf.h +++ b/include/linux/dma-buf.h @@ -51,6 +51,15 @@ struct dma_buf_attachment; * @vunmap: [optional] unmaps a vmap from the buffer */ struct dma_buf_ops { + /** + * @cache_sgt_mapping: + * + * If true the framework will cache the first mapping made for each + * attachment. This avoids creating mappings for attachments multiple + * times. + */ + bool cache_sgt_mapping; + /** * @attach: * @@ -307,6 +316,8 @@ struct dma_buf { * @dmabuf: buffer for this attachment. * @dev: device attached to the buffer. * @node: list of dma_buf_attachment. + * @sgt: cached mapping. + * @dir: direction of cached mapping. * @priv: exporter specific attachment data. * * This structure holds the attachment information between the dma_buf buffer @@ -322,6 +333,8 @@ struct dma_buf_attachment { struct dma_buf *dmabuf; struct device *dev; struct list_head node; + struct sg_table *sgt; + enum dma_data_direction dir; void *priv; };
To allow a smooth transition from pinning buffer objects to dynamic invalidation we first start to cache the sg_table for an attachment. v2: keep closer to the DRM implementation Signed-off-by: Christian König <christian.koenig@amd.com> --- drivers/dma-buf/dma-buf.c | 27 +++++++++++++++++++++++++-- include/linux/dma-buf.h | 13 +++++++++++++ 2 files changed, 38 insertions(+), 2 deletions(-)