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[2/6] v4l: vsp1: Provide a fragment pool

Message ID 4381803c9ed872a8c746057ef88678bb715856f8.1500047489.git-series.kieran.bingham+renesas@ideasonboard.com (mailing list archive)
State New, archived
Headers show

Commit Message

Kieran Bingham July 14, 2017, 4:14 p.m. UTC
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+renesas@ideasonboard.com>
---
 drivers/media/platform/vsp1/vsp1_dl.c | 124 +++++++++++++++++++++++++++-
 drivers/media/platform/vsp1/vsp1_dl.h |   8 ++-
 2 files changed, 132 insertions(+)
diff mbox

Patch

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);