From 9489a8ff0a13fc0f62e556a31341d3bbaef9da6b Mon Sep 17 00:00:00 2001 From: Laurent Pinchart Date: Fri, 13 May 2016 19:17:02 -0300 Subject: [media] v4l: vsp1: dl: Don't free fragments with interrupts disabled Freeing a fragment requires freeing DMA coherent memory, which can be performed with interrupts disabled as per the DMA mapping API contract. The fragments can't thus be freed synchronously when a display list is recycled. Instead, move the fragments to a garbage list and use a work queue to run the garbage collection. Signed-off-by: Laurent Pinchart Signed-off-by: Mauro Carvalho Chehab --- drivers/media/platform/vsp1/vsp1_dl.c | 72 ++++++++++++++++++++++++++++------- 1 file changed, 58 insertions(+), 14 deletions(-) (limited to 'drivers/media/platform') diff --git a/drivers/media/platform/vsp1/vsp1_dl.c b/drivers/media/platform/vsp1/vsp1_dl.c index e238d9b9376b..37c3518aa2a8 100644 --- a/drivers/media/platform/vsp1/vsp1_dl.c +++ b/drivers/media/platform/vsp1/vsp1_dl.c @@ -15,6 +15,7 @@ #include #include #include +#include #include "vsp1.h" #include "vsp1_dl.h" @@ -92,11 +93,13 @@ enum vsp1_dl_mode { * @index: index of the related WPF * @mode: display list operation mode (header or headerless) * @vsp1: the VSP1 device - * @lock: protects the active, queued and pending lists + * @lock: protects the free, active, queued, pending and gc_fragments lists * @free: array of all free display lists * @active: list currently being processed (loaded) by hardware * @queued: list queued to the hardware (written to the DL registers) * @pending: list waiting to be queued to the hardware + * @gc_work: fragments garbage collector work struct + * @gc_fragments: array of display list fragments waiting to be freed */ struct vsp1_dl_manager { unsigned int index; @@ -108,6 +111,9 @@ struct vsp1_dl_manager { struct vsp1_dl_list *active; struct vsp1_dl_list *queued; struct vsp1_dl_list *pending; + + struct work_struct gc_work; + struct list_head gc_fragments; }; /* ----------------------------------------------------------------------------- @@ -262,21 +268,10 @@ static struct vsp1_dl_list *vsp1_dl_list_alloc(struct vsp1_dl_manager *dlm) return dl; } -static void vsp1_dl_list_free_fragments(struct vsp1_dl_list *dl) -{ - struct vsp1_dl_body *dlb, *next; - - list_for_each_entry_safe(dlb, next, &dl->fragments, list) { - list_del(&dlb->list); - vsp1_dl_body_cleanup(dlb); - kfree(dlb); - } -} - static void vsp1_dl_list_free(struct vsp1_dl_list *dl) { vsp1_dl_body_cleanup(&dl->body0); - vsp1_dl_list_free_fragments(dl); + list_splice_init(&dl->fragments, &dl->dlm->gc_fragments); kfree(dl); } @@ -311,7 +306,16 @@ static void __vsp1_dl_list_put(struct vsp1_dl_list *dl) if (!dl) return; - vsp1_dl_list_free_fragments(dl); + /* We can't free fragments here as DMA memory can only be freed in + * interruptible context. Move all fragments to the display list + * manager's list of fragments to be freed, they will be + * garbage-collected by the work queue. + */ + if (!list_empty(&dl->fragments)) { + list_splice_init(&dl->fragments, &dl->dlm->gc_fragments); + schedule_work(&dl->dlm->gc_work); + } + dl->body0.num_entries = 0; list_add_tail(&dl->list, &dl->dlm->free); @@ -550,6 +554,40 @@ void vsp1_dlm_reset(struct vsp1_dl_manager *dlm) dlm->pending = NULL; } +/* + * Free all fragments awaiting to be garbage-collected. + * + * This function must be called without the display list manager lock held. + */ +static void vsp1_dlm_fragments_free(struct vsp1_dl_manager *dlm) +{ + unsigned long flags; + + spin_lock_irqsave(&dlm->lock, flags); + + while (!list_empty(&dlm->gc_fragments)) { + struct vsp1_dl_body *dlb; + + dlb = list_first_entry(&dlm->gc_fragments, struct vsp1_dl_body, + list); + list_del(&dlb->list); + + spin_unlock_irqrestore(&dlm->lock, flags); + vsp1_dl_fragment_free(dlb); + spin_lock_irqsave(&dlm->lock, flags); + } + + spin_unlock_irqrestore(&dlm->lock, flags); +} + +static void vsp1_dlm_garbage_collect(struct work_struct *work) +{ + struct vsp1_dl_manager *dlm = + container_of(work, struct vsp1_dl_manager, gc_work); + + vsp1_dlm_fragments_free(dlm); +} + struct vsp1_dl_manager *vsp1_dlm_create(struct vsp1_device *vsp1, unsigned int index, unsigned int prealloc) @@ -568,6 +606,8 @@ struct vsp1_dl_manager *vsp1_dlm_create(struct vsp1_device *vsp1, spin_lock_init(&dlm->lock); INIT_LIST_HEAD(&dlm->free); + INIT_LIST_HEAD(&dlm->gc_fragments); + INIT_WORK(&dlm->gc_work, vsp1_dlm_garbage_collect); for (i = 0; i < prealloc; ++i) { struct vsp1_dl_list *dl; @@ -589,8 +629,12 @@ void vsp1_dlm_destroy(struct vsp1_dl_manager *dlm) if (!dlm) return; + cancel_work_sync(&dlm->gc_work); + list_for_each_entry_safe(dl, next, &dlm->free, list) { list_del(&dl->list); vsp1_dl_list_free(dl); } + + vsp1_dlm_fragments_free(dlm); } -- cgit v1.2.3