Each display list allocates a body to store register values in a dma
accessible buffer from a dma_alloc_wc() allocation. Each of these
results in an entry in the TLB, and a large number of display list
allocations adds pressure to this resource.
Reduce TLB pressure on the IPMMUs by allocating multiple display list
bodies in a single allocation, and providing these to the display list
through a 'fragment pool'. A pool can be allocated by the display list
manager or entities which require their own body allocations.
Signed-off-by: Kieran Bingham <kieran.bingham+rene...@ideasonboard.com>
---
drivers/media/platform/vsp1/vsp1_dl.c | 124 +++++++++++++++++++++++++++-
drivers/media/platform/vsp1/vsp1_dl.h | 8 ++-
2 files changed, 132 insertions(+)
diff --git a/drivers/media/platform/vsp1/vsp1_dl.c
b/drivers/media/platform/vsp1/vsp1_dl.c
index 1311e7cf2733..8b1118c2e8f5 100644
--- a/drivers/media/platform/vsp1/vsp1_dl.c
+++ b/drivers/media/platform/vsp1/vsp1_dl.c
@@ -45,6 +45,7 @@ struct vsp1_dl_entry {
/**
* struct vsp1_dl_body - Display list body
* @list: entry in the display list list of bodies
+ * @pool: entry in the pool list for free/used dlbs
* @vsp1: the VSP1 device
* @entries: array of entries
* @dma: DMA address of the entries
@@ -53,6 +54,9 @@ struct vsp1_dl_entry {
*/
struct vsp1_dl_body {
struct list_head list;
+ struct list_head free;
+
+ struct vsp1_dl_fragment_pool *pool;
struct vsp1_device *vsp1;
struct vsp1_dl_entry *entries;
@@ -64,6 +68,29 @@ struct vsp1_dl_body {
};
/**
+ * struct vsp1_dl_fragment_pool - display list body/fragment pool
+ * @dma: DMA address of the entries
+ * @size: size of the full DMA memory pool in bytes
+ * @mem: CPU memory pointer for the pool
+ * @bodies: Array of DLB structures for the pool
+ * @free: List of free DLB entries
+ * @used: List of active DLB entries
+ */
+struct vsp1_dl_fragment_pool {
+ /* DMA allocation */
+ dma_addr_t dma;
+ size_t size;
+ void *mem;
+
+ /* Body management */
+ struct vsp1_dl_body *bodies;
+ struct list_head free;
+ spinlock_t lock;
+
+ struct vsp1_device *vsp1;
+};
+
+/**
* struct vsp1_dl_list - Display list
* @list: entry in the display list manager lists
* @dlm: the display list manager
@@ -118,6 +145,8 @@ struct vsp1_dl_manager {
struct vsp1_dl_list *queued;
struct vsp1_dl_list *pending;
+ struct vsp1_dl_fragment_pool *pool;
+
struct work_struct gc_work;
struct list_head gc_fragments;
};
@@ -127,6 +156,101 @@ struct vsp1_dl_manager {
*/
/*
+ * Fragment pool's reduce the pressure on the iommu TLB by allocating a single
+ * large area of DMA memory and allocating it as a pool of fragment bodies
+ */
+struct vsp1_dl_fragment_pool *
+vsp1_dl_fragment_pool_alloc(struct vsp1_device *vsp1, unsigned int qty,
+ unsigned int num_entries, size_t extra_size)
+{
+ struct vsp1_dl_fragment_pool *pool;
+ size_t dlb_size;
+ unsigned int i;
+
+ pool = kzalloc(sizeof(*pool), GFP_KERNEL);
+ if (!pool)
+ return NULL;
+
+ pool->vsp1 = vsp1;
+
+ dlb_size = num_entries * sizeof(struct vsp1_dl_entry) + extra_size;
+ pool->size = dlb_size * qty;
+
+ pool->bodies = kcalloc(qty, sizeof(*pool->bodies), GFP_KERNEL);
+ if (!pool->bodies) {
+ kfree(pool);
+ return NULL;
+ }
+
+ pool->mem = dma_alloc_wc(vsp1->bus_master, pool->size, &pool->dma,
+ GFP_KERNEL);
+ if (!pool->mem) {
+ kfree(pool->bodies);
+ kfree(pool);
+ return NULL;
+ }
+
+ spin_lock_init(&pool->lock);
+ INIT_LIST_HEAD(&pool->free);
+
+ for (i = 0; i < qty; ++i) {
+ struct vsp1_dl_body *dlb = &pool->bodies[i];
+
+ dlb->pool = pool;
+ dlb->max_entries = num_entries;
+ dlb->entries = pool->mem + i * dlb_size;
+
+ list_add_tail(&dlb->free, &pool->free);
+ }
+
+ return pool;
+}
+
+void vsp1_dl_fragment_pool_free(struct vsp1_dl_fragment_pool *pool)
+{
+ if (!pool)
+ return;
+
+ if (pool->mem)
+ dma_free_wc(pool->vsp1->bus_master, pool->size, pool->mem,
+ pool->dma);
+
+ kfree(pool->bodies);
+ kfree(pool);
+}
+
+struct vsp1_dl_body *vsp1_dl_fragment_get(struct vsp1_dl_fragment_pool *pool)
+{
+ struct vsp1_dl_body *dlb = NULL;
+ unsigned long flags;
+
+ spin_lock_irqsave(&pool->lock, flags);
+
+ if (!list_empty(&pool->free)) {
+ dlb = list_first_entry(&pool->free, struct vsp1_dl_body, free);
+ list_del(&dlb->free);
+ }
+
+ spin_unlock_irqrestore(&pool->lock, flags);
+
+ return dlb;
+}
+
+void vsp1_dl_fragment_put(struct vsp1_dl_body *dlb)
+{
+ unsigned long flags;
+
+ if (!dlb)
+ return;
+
+ dlb->num_entries = 0;
+
+ spin_lock_irqsave(&dlb->pool->lock, flags);
+ list_add_tail(&dlb->free, &dlb->pool->free);
+ spin_unlock_irqrestore(&dlb->pool->lock, flags);
+}
+
+/*
* Initialize a display list body object and allocate DMA memory for the body
* data. The display list body object is expected to have been initialized to
* 0 when allocated.
diff --git a/drivers/media/platform/vsp1/vsp1_dl.h
b/drivers/media/platform/vsp1/vsp1_dl.h
index ee3508172f0a..9528484a8a34 100644
--- a/drivers/media/platform/vsp1/vsp1_dl.h
+++ b/drivers/media/platform/vsp1/vsp1_dl.h
@@ -17,6 +17,7 @@
struct vsp1_device;
struct vsp1_dl_fragment;
+struct vsp1_dl_fragment_pool;
struct vsp1_dl_list;
struct vsp1_dl_manager;
@@ -34,6 +35,13 @@ void vsp1_dl_list_put(struct vsp1_dl_list *dl);
void vsp1_dl_list_write(struct vsp1_dl_list *dl, u32 reg, u32 data);
void vsp1_dl_list_commit(struct vsp1_dl_list *dl);
+struct vsp1_dl_fragment_pool *
+vsp1_dl_fragment_pool_alloc(struct vsp1_device *vsp1, unsigned int qty,
+ unsigned int num_entries, size_t extra_size);
+void vsp1_dl_fragment_pool_free(struct vsp1_dl_fragment_pool *pool);
+struct vsp1_dl_body *vsp1_dl_fragment_get(struct vsp1_dl_fragment_pool *pool);
+void vsp1_dl_fragment_put(struct vsp1_dl_body *dlb);
+
struct vsp1_dl_body *vsp1_dl_fragment_alloc(struct vsp1_device *vsp1,
unsigned int num_entries);
void vsp1_dl_fragment_free(struct vsp1_dl_body *dlb);
--
git-series 0.9.1
