| Message ID | 20180601120020.11520-4-christian.koenig@amd.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Fri, Jun 01, 2018 at 02:00:19PM +0200, Christian König wrote: > Add function variants which can be called with the reservation lock > already held. > > Signed-off-by: Christian König <christian.koenig@amd.com> I expect that we'll need this patch before patch 3 and then roll it out to drivers doing reservation locking already, before we can add the reservation stuff for all other callers. > --- > drivers/dma-buf/dma-buf.c | 60 ++++++++++++++++++++++++++++++++++++++++++----- > include/linux/dma-buf.h | 5 ++++ > 2 files changed, 59 insertions(+), 6 deletions(-) > > diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c > index 4f0708cb58a7..3371509b468e 100644 > --- a/drivers/dma-buf/dma-buf.c > +++ b/drivers/dma-buf/dma-buf.c > @@ -606,6 +606,38 @@ void dma_buf_detach(struct dma_buf *dmabuf, struct dma_buf_attachment *attach) > } > EXPORT_SYMBOL_GPL(dma_buf_detach); > > +/** > + * dma_buf_map_attachment_locked - Maps the buffer into _device_ address space > + * with the reservation lock held. Is a wrapper for map_dma_buf() of the > + * > + * Returns the scatterlist table of the attachment; > + * dma_buf_ops. > + * @attach: [in] attachment whose scatterlist is to be returned > + * @direction: [in] direction of DMA transfer > + * > + * Returns sg_table containing the scatterlist to be returned; returns ERR_PTR > + * on error. May return -EINTR if it is interrupted by a signal. > + * > + * A mapping must be unmapped by using dma_buf_unmap_attachment(). Note that _locked Also please reference the other variants here for doc completeness. > + * the underlying backing storage is pinned for as long as a mapping exists, > + * therefore users/importers should not hold onto a mapping for undue amounts of > + * time. > + */ > +struct sg_table * > +dma_buf_map_attachment_locked(struct dma_buf_attachment *attach, > + enum dma_data_direction direction) > +{ > + struct sg_table *sg_table; > + > + might_sleep(); Needs a lockdep_assert_held here. > + sg_table = attach->dmabuf->ops->map_dma_buf(attach, direction); > + if (!sg_table) > + sg_table = ERR_PTR(-ENOMEM); > + > + return sg_table; > +} > +EXPORT_SYMBOL_GPL(dma_buf_map_attachment_locked); > + > /** > * dma_buf_map_attachment - Returns the scatterlist table of the attachment; > * mapped into _device_ address space. Is a wrapper for map_dma_buf() of the > @@ -626,13 +658,12 @@ struct sg_table *dma_buf_map_attachment(struct dma_buf_attachment *attach, > { > struct sg_table *sg_table; > > - might_sleep(); > > if (WARN_ON(!attach || !attach->dmabuf)) > return ERR_PTR(-EINVAL); > > reservation_object_lock(attach->dmabuf->resv, NULL); > - sg_table = attach->dmabuf->ops->map_dma_buf(attach, direction); > + sg_table = dma_buf_map_attachment_locked(attach, direction); > reservation_object_unlock(attach->dmabuf->resv); > if (!sg_table) > sg_table = ERR_PTR(-ENOMEM); > @@ -641,6 +672,26 @@ struct sg_table *dma_buf_map_attachment(struct dma_buf_attachment *attach, > } > EXPORT_SYMBOL_GPL(dma_buf_map_attachment); > > +/** > + * dma_buf_unmap_attachment_locked - unmaps the buffer with reservation lock > + * held, should deallocate the associated scatterlist. Is a wrapper for > + * unmap_dma_buf() of dma_buf_ops. > + * @attach: [in] attachment to unmap buffer from > + * @sg_table: [in] scatterlist info of the buffer to unmap > + * @direction: [in] direction of DMA transfer > + * > + * This unmaps a DMA mapping for @attached obtained by dma_buf_map_attachment(). _locked > + */ > +void dma_buf_unmap_attachment_locked(struct dma_buf_attachment *attach, > + struct sg_table *sg_table, > + enum dma_data_direction direction) > +{ > + might_sleep(); Needs a lockdep_assert_held here. Otherwise lgtm, but there's the big caveat of that I expect lockdep fireworks on mass with this, but drivers not yet converted. -Daniel > + attach->dmabuf->ops->unmap_dma_buf(attach, sg_table, > + direction); > +} > +EXPORT_SYMBOL_GPL(dma_buf_unmap_attachment_locked); > + > /** > * dma_buf_unmap_attachment - unmaps and decreases usecount of the buffer;might > * deallocate the scatterlist associated. Is a wrapper for unmap_dma_buf() of > @@ -655,14 +706,11 @@ void dma_buf_unmap_attachment(struct dma_buf_attachment *attach, > struct sg_table *sg_table, > enum dma_data_direction direction) > { > - might_sleep(); > - > if (WARN_ON(!attach || !attach->dmabuf || !sg_table)) > return; > > reservation_object_lock(attach->dmabuf->resv, NULL); > - attach->dmabuf->ops->unmap_dma_buf(attach, sg_table, > - direction); > + dma_buf_unmap_attachment_locked(attach, sg_table, direction); > reservation_object_unlock(attach->dmabuf->resv); > } > EXPORT_SYMBOL_GPL(dma_buf_unmap_attachment); > diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h > index d2ba7a027a78..968777e8c662 100644 > --- a/include/linux/dma-buf.h > +++ b/include/linux/dma-buf.h > @@ -388,8 +388,13 @@ int dma_buf_fd(struct dma_buf *dmabuf, int flags); > struct dma_buf *dma_buf_get(int fd); > void dma_buf_put(struct dma_buf *dmabuf); > > +struct sg_table *dma_buf_map_attachment_locked(struct dma_buf_attachment *, > + enum dma_data_direction); > struct sg_table *dma_buf_map_attachment(struct dma_buf_attachment *, > enum dma_data_direction); > +void dma_buf_unmap_attachment_locked(struct dma_buf_attachment *, > + struct sg_table *, > + enum dma_data_direction); > void dma_buf_unmap_attachment(struct dma_buf_attachment *, struct sg_table *, > enum dma_data_direction); > int dma_buf_begin_cpu_access(struct dma_buf *dma_buf, > -- > 2.14.1 > > _______________________________________________ > dri-devel mailing list > dri-devel@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/dri-devel
diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c index 4f0708cb58a7..3371509b468e 100644 --- a/drivers/dma-buf/dma-buf.c +++ b/drivers/dma-buf/dma-buf.c @@ -606,6 +606,38 @@ void dma_buf_detach(struct dma_buf *dmabuf, struct dma_buf_attachment *attach) } EXPORT_SYMBOL_GPL(dma_buf_detach); +/** + * dma_buf_map_attachment_locked - Maps the buffer into _device_ address space + * with the reservation lock held. Is a wrapper for map_dma_buf() of the + * + * Returns the scatterlist table of the attachment; + * dma_buf_ops. + * @attach: [in] attachment whose scatterlist is to be returned + * @direction: [in] direction of DMA transfer + * + * Returns sg_table containing the scatterlist to be returned; returns ERR_PTR + * on error. May return -EINTR if it is interrupted by a signal. + * + * A mapping must be unmapped by using dma_buf_unmap_attachment(). Note that + * the underlying backing storage is pinned for as long as a mapping exists, + * therefore users/importers should not hold onto a mapping for undue amounts of + * time. + */ +struct sg_table * +dma_buf_map_attachment_locked(struct dma_buf_attachment *attach, + enum dma_data_direction direction) +{ + struct sg_table *sg_table; + + might_sleep(); + sg_table = attach->dmabuf->ops->map_dma_buf(attach, direction); + if (!sg_table) + sg_table = ERR_PTR(-ENOMEM); + + return sg_table; +} +EXPORT_SYMBOL_GPL(dma_buf_map_attachment_locked); + /** * dma_buf_map_attachment - Returns the scatterlist table of the attachment; * mapped into _device_ address space. Is a wrapper for map_dma_buf() of the @@ -626,13 +658,12 @@ struct sg_table *dma_buf_map_attachment(struct dma_buf_attachment *attach, { struct sg_table *sg_table; - might_sleep(); if (WARN_ON(!attach || !attach->dmabuf)) return ERR_PTR(-EINVAL); reservation_object_lock(attach->dmabuf->resv, NULL); - sg_table = attach->dmabuf->ops->map_dma_buf(attach, direction); + sg_table = dma_buf_map_attachment_locked(attach, direction); reservation_object_unlock(attach->dmabuf->resv); if (!sg_table) sg_table = ERR_PTR(-ENOMEM); @@ -641,6 +672,26 @@ struct sg_table *dma_buf_map_attachment(struct dma_buf_attachment *attach, } EXPORT_SYMBOL_GPL(dma_buf_map_attachment); +/** + * dma_buf_unmap_attachment_locked - unmaps the buffer with reservation lock + * held, should deallocate the associated scatterlist. Is a wrapper for + * unmap_dma_buf() of dma_buf_ops. + * @attach: [in] attachment to unmap buffer from + * @sg_table: [in] scatterlist info of the buffer to unmap + * @direction: [in] direction of DMA transfer + * + * This unmaps a DMA mapping for @attached obtained by dma_buf_map_attachment(). + */ +void dma_buf_unmap_attachment_locked(struct dma_buf_attachment *attach, + struct sg_table *sg_table, + enum dma_data_direction direction) +{ + might_sleep(); + attach->dmabuf->ops->unmap_dma_buf(attach, sg_table, + direction); +} +EXPORT_SYMBOL_GPL(dma_buf_unmap_attachment_locked); + /** * dma_buf_unmap_attachment - unmaps and decreases usecount of the buffer;might * deallocate the scatterlist associated. Is a wrapper for unmap_dma_buf() of @@ -655,14 +706,11 @@ void dma_buf_unmap_attachment(struct dma_buf_attachment *attach, struct sg_table *sg_table, enum dma_data_direction direction) { - might_sleep(); - if (WARN_ON(!attach || !attach->dmabuf || !sg_table)) return; reservation_object_lock(attach->dmabuf->resv, NULL); - attach->dmabuf->ops->unmap_dma_buf(attach, sg_table, - direction); + dma_buf_unmap_attachment_locked(attach, sg_table, direction); reservation_object_unlock(attach->dmabuf->resv); } EXPORT_SYMBOL_GPL(dma_buf_unmap_attachment); diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h index d2ba7a027a78..968777e8c662 100644 --- a/include/linux/dma-buf.h +++ b/include/linux/dma-buf.h @@ -388,8 +388,13 @@ int dma_buf_fd(struct dma_buf *dmabuf, int flags); struct dma_buf *dma_buf_get(int fd); void dma_buf_put(struct dma_buf *dmabuf); +struct sg_table *dma_buf_map_attachment_locked(struct dma_buf_attachment *, + enum dma_data_direction); struct sg_table *dma_buf_map_attachment(struct dma_buf_attachment *, enum dma_data_direction); +void dma_buf_unmap_attachment_locked(struct dma_buf_attachment *, + struct sg_table *, + enum dma_data_direction); void dma_buf_unmap_attachment(struct dma_buf_attachment *, struct sg_table *, enum dma_data_direction); int dma_buf_begin_cpu_access(struct dma_buf *dma_buf,
Add function variants which can be called with the reservation lock already held. Signed-off-by: Christian König <christian.koenig@amd.com> --- drivers/dma-buf/dma-buf.c | 60 ++++++++++++++++++++++++++++++++++++++++++----- include/linux/dma-buf.h | 5 ++++ 2 files changed, 59 insertions(+), 6 deletions(-)