| Message ID | d28cb6bce32d33479f5d5b49e67c4c79a9b7b4bc.1502723341.git-series.kieran.bingham+renesas@ideasonboard.com (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Geert Uytterhoeven |
| Headers | show |
Hi Kieran, Thank you for the patch. On Monday 14 Aug 2017 16:13:27 Kieran Bingham wrote: > Extend the display list body with a reference count, allowing bodies to > be kept as long as a reference is maintained. This provides the ability > to keep a cached copy of bodies which will not change, so that they can > be re-applied to multiple display lists. > > Signed-off-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com> > > --- > This could be squashed into the fragment update code, but it's not a > straightforward squash as the refcounts will affect both: > v4l: vsp1: Provide a fragment pool > and > v4l: vsp1: Convert display lists to use new fragment pool > therefore, I have kept this separate to prevent breaking bisectability > of the vsp-tests. Sounds good to me. > --- > drivers/media/platform/vsp1/vsp1_clu.c | 7 ++++++- > drivers/media/platform/vsp1/vsp1_dl.c | 15 ++++++++++++++- > drivers/media/platform/vsp1/vsp1_lut.c | 7 ++++++- > 3 files changed, 26 insertions(+), 3 deletions(-) > > diff --git a/drivers/media/platform/vsp1/vsp1_clu.c > b/drivers/media/platform/vsp1/vsp1_clu.c index 52c523625e2f..175717018e11 > 100644 > --- a/drivers/media/platform/vsp1/vsp1_clu.c > +++ b/drivers/media/platform/vsp1/vsp1_clu.c > @@ -257,8 +257,13 @@ static void clu_configure(struct vsp1_entity *entity, > clu->clu = NULL; > spin_unlock_irqrestore(&clu->lock, flags); > > - if (dlb) > + if (dlb) { > vsp1_dl_list_add_fragment(dl, dlb); > + > + /* release our local reference */ > + vsp1_dl_fragment_put(dlb); > + } > + > break; > } > } > diff --git a/drivers/media/platform/vsp1/vsp1_dl.c > b/drivers/media/platform/vsp1/vsp1_dl.c index 6ffdc3549283..37feda248946 > 100644 > --- a/drivers/media/platform/vsp1/vsp1_dl.c > +++ b/drivers/media/platform/vsp1/vsp1_dl.c > @@ -14,6 +14,7 @@ > #include <linux/device.h> > #include <linux/dma-mapping.h> > #include <linux/gfp.h> > +#include <linux/refcount.h> > #include <linux/slab.h> > #include <linux/workqueue.h> > > @@ -58,6 +59,8 @@ struct vsp1_dl_body { > struct list_head list; > struct list_head free; > > + refcount_t refcnt; > + > struct vsp1_dl_fragment_pool *pool; > struct vsp1_device *vsp1; > > @@ -230,6 +233,7 @@ struct vsp1_dl_body *vsp1_dl_fragment_get(struct > vsp1_dl_fragment_pool *pool) > if (!list_empty(&pool->free)) { > dlb = list_first_entry(&pool->free, struct vsp1_dl_body, > free); > list_del(&dlb->free); > + refcount_set(&dlb->refcnt, 1); > } > > spin_unlock_irqrestore(&pool->lock, flags); > @@ -244,6 +248,9 @@ void vsp1_dl_fragment_put(struct vsp1_dl_body *dlb) > if (!dlb) > return; > > + if (!refcount_dec_and_test(&dlb->refcnt)) > + return; > + > dlb->num_entries = 0; > > spin_lock_irqsave(&dlb->pool->lock, flags); > @@ -428,7 +435,11 @@ void vsp1_dl_list_write(struct vsp1_dl_list *dl, u32 > reg, u32 data) > * list, in the order in which fragments are added. > * > * Adding a fragment to a display list passes ownership of the fragment to > the > - * list. The caller must not touch the fragment after this call. > + * list. The caller must not modify the fragment after this call, but can > retain > + * a reference to it for future use if necessary, to add to subsequent > lists. I think there's a bit of contradiction here, if the ownership passes to the list then the caller shouldn't touch it anymore. How about stating it as follows ? * The caller retains its reference to the fragment when adding it to a * display list, but is not allowed to add new entries to the fragment. * The reference must be explicitly released by a call to * vsp1_dl_fragment_put() when the fragment isn't needed anymore. > the > - * list. The caller must not touch the fragment after this call. > + * list. The caller must not modify the fragment after this call, but can > retain > + * a reference to it for future use if necessary, to add to subsequent > lists. > + * > + * The reference count of the body is incremented by this attachment, and > thus > + * the caller should release it's reference if does not want to cache the > body. > * > * Fragments are only usable for display lists in header mode. Attempt to > * add a fragment to a header-less display list will return an error. > @@ -440,6 +451,8 @@ int vsp1_dl_list_add_fragment(struct vsp1_dl_list *dl, > if (dl->dlm->mode != VSP1_DL_MODE_HEADER) > return -EINVAL; > > + refcount_inc(&dlb->refcnt); > + > list_add_tail(&dlb->list, &dl->fragments); > return 0; > } > diff --git a/drivers/media/platform/vsp1/vsp1_lut.c > b/drivers/media/platform/vsp1/vsp1_lut.c index 57482e057e54..388bd89ade0b > 100644 > --- a/drivers/media/platform/vsp1/vsp1_lut.c > +++ b/drivers/media/platform/vsp1/vsp1_lut.c > @@ -213,8 +213,13 @@ static void lut_configure(struct vsp1_entity *entity, > lut->lut = NULL; > spin_unlock_irqrestore(&lut->lock, flags); > > - if (dlb) > + if (dlb) { > vsp1_dl_list_add_fragment(dl, dlb); > + > + /* release our local reference */ > + vsp1_dl_fragment_put(dlb); > + } > + > break; > } > }
diff --git a/drivers/media/platform/vsp1/vsp1_clu.c b/drivers/media/platform/vsp1/vsp1_clu.c index 52c523625e2f..175717018e11 100644 --- a/drivers/media/platform/vsp1/vsp1_clu.c +++ b/drivers/media/platform/vsp1/vsp1_clu.c @@ -257,8 +257,13 @@ static void clu_configure(struct vsp1_entity *entity, clu->clu = NULL; spin_unlock_irqrestore(&clu->lock, flags); - if (dlb) + if (dlb) { vsp1_dl_list_add_fragment(dl, dlb); + + /* release our local reference */ + vsp1_dl_fragment_put(dlb); + } + break; } } diff --git a/drivers/media/platform/vsp1/vsp1_dl.c b/drivers/media/platform/vsp1/vsp1_dl.c index 6ffdc3549283..37feda248946 100644 --- a/drivers/media/platform/vsp1/vsp1_dl.c +++ b/drivers/media/platform/vsp1/vsp1_dl.c @@ -14,6 +14,7 @@ #include <linux/device.h> #include <linux/dma-mapping.h> #include <linux/gfp.h> +#include <linux/refcount.h> #include <linux/slab.h> #include <linux/workqueue.h> @@ -58,6 +59,8 @@ struct vsp1_dl_body { struct list_head list; struct list_head free; + refcount_t refcnt; + struct vsp1_dl_fragment_pool *pool; struct vsp1_device *vsp1; @@ -230,6 +233,7 @@ struct vsp1_dl_body *vsp1_dl_fragment_get(struct vsp1_dl_fragment_pool *pool) if (!list_empty(&pool->free)) { dlb = list_first_entry(&pool->free, struct vsp1_dl_body, free); list_del(&dlb->free); + refcount_set(&dlb->refcnt, 1); } spin_unlock_irqrestore(&pool->lock, flags); @@ -244,6 +248,9 @@ void vsp1_dl_fragment_put(struct vsp1_dl_body *dlb) if (!dlb) return; + if (!refcount_dec_and_test(&dlb->refcnt)) + return; + dlb->num_entries = 0; spin_lock_irqsave(&dlb->pool->lock, flags); @@ -428,7 +435,11 @@ void vsp1_dl_list_write(struct vsp1_dl_list *dl, u32 reg, u32 data) * list, in the order in which fragments are added. * * Adding a fragment to a display list passes ownership of the fragment to the - * list. The caller must not touch the fragment after this call. + * list. The caller must not modify the fragment after this call, but can retain + * a reference to it for future use if necessary, to add to subsequent lists. + * + * The reference count of the body is incremented by this attachment, and thus + * the caller should release it's reference if does not want to cache the body. * * Fragments are only usable for display lists in header mode. Attempt to * add a fragment to a header-less display list will return an error. @@ -440,6 +451,8 @@ int vsp1_dl_list_add_fragment(struct vsp1_dl_list *dl, if (dl->dlm->mode != VSP1_DL_MODE_HEADER) return -EINVAL; + refcount_inc(&dlb->refcnt); + list_add_tail(&dlb->list, &dl->fragments); return 0; } diff --git a/drivers/media/platform/vsp1/vsp1_lut.c b/drivers/media/platform/vsp1/vsp1_lut.c index 57482e057e54..388bd89ade0b 100644 --- a/drivers/media/platform/vsp1/vsp1_lut.c +++ b/drivers/media/platform/vsp1/vsp1_lut.c @@ -213,8 +213,13 @@ static void lut_configure(struct vsp1_entity *entity, lut->lut = NULL; spin_unlock_irqrestore(&lut->lock, flags); - if (dlb) + if (dlb) { vsp1_dl_list_add_fragment(dl, dlb); + + /* release our local reference */ + vsp1_dl_fragment_put(dlb); + } + break; } }
Extend the display list body with a reference count, allowing bodies to be kept as long as a reference is maintained. This provides the ability to keep a cached copy of bodies which will not change, so that they can be re-applied to multiple display lists. Signed-off-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com> --- This could be squashed into the fragment update code, but it's not a straightforward squash as the refcounts will affect both: v4l: vsp1: Provide a fragment pool and v4l: vsp1: Convert display lists to use new fragment pool therefore, I have kept this separate to prevent breaking bisectability of the vsp-tests. --- drivers/media/platform/vsp1/vsp1_clu.c | 7 ++++++- drivers/media/platform/vsp1/vsp1_dl.c | 15 ++++++++++++++- drivers/media/platform/vsp1/vsp1_lut.c | 7 ++++++- 3 files changed, 26 insertions(+), 3 deletions(-)