Commit a9510202 authored by T.J. Mercier's avatar T.J. Mercier Committed by Sumit Semwal
Browse files

dma-buf: system_heap: No separate allocation for attachment sg_tables 



struct dma_heap_attachment is a separate allocation from the struct
sg_table it contains, but there is no reason for this. Let's use the
slab allocator just once instead of twice for dma_heap_attachment.

Signed-off-by: default avatarT.J. Mercier <tjmercier@google.com>
Reviewed-by: default avatarChristian König <christian.koenig@amd.com>
Signed-off-by: default avatarSumit Semwal <sumit.semwal@linaro.org>
Link: https://lore.kernel.org/r/20250417180943.1559755-1-tjmercier@google.com
parent fe88fb34

drivers/dma-buf/heaps/system_heap.c

+17 −26
Original line number Diff line number Diff line
@@ -33,7 +33,7 @@ struct system_heap_buffer { 


struct dma_heap_attachment {

	struct device *dev;

	struct sg_table *table;

	struct sg_table table;

	struct list_head list;

	bool mapped;

};
@@ -52,29 +52,22 @@ static gfp_t order_flags[] = {HIGH_ORDER_GFP, HIGH_ORDER_GFP, LOW_ORDER_GFP}; 
static const unsigned int orders[] = {8, 4, 0};

#define NUM_ORDERS ARRAY_SIZE(orders)



static struct sg_table *dup_sg_table(struct sg_table *table)

static int dup_sg_table(struct sg_table *from, struct sg_table *to)

{

	struct sg_table *new_table;

	int ret, i;

	struct scatterlist *sg, *new_sg;

	int ret, i;



	new_table = kzalloc(sizeof(*new_table), GFP_KERNEL);

	if (!new_table)

		return ERR_PTR(-ENOMEM);



	ret = sg_alloc_table(new_table, table->orig_nents, GFP_KERNEL);

	if (ret) {

		kfree(new_table);

		return ERR_PTR(-ENOMEM);

	}

	ret = sg_alloc_table(to, from->orig_nents, GFP_KERNEL);

	if (ret)

		return ret;



	new_sg = new_table->sgl;

	for_each_sgtable_sg(table, sg, i) {

	new_sg = to->sgl;

	for_each_sgtable_sg(from, sg, i) {

		sg_set_page(new_sg, sg_page(sg), sg->length, sg->offset);

		new_sg = sg_next(new_sg);

	}



	return new_table;

	return 0;

}



static int system_heap_attach(struct dma_buf *dmabuf,
@@ -82,19 +75,18 @@ static int system_heap_attach(struct dma_buf *dmabuf, 
{

	struct system_heap_buffer *buffer = dmabuf->priv;

	struct dma_heap_attachment *a;

	struct sg_table *table;

	int ret;



	a = kzalloc(sizeof(*a), GFP_KERNEL);

	if (!a)

		return -ENOMEM;



	table = dup_sg_table(&buffer->sg_table);

	if (IS_ERR(table)) {

	ret = dup_sg_table(&buffer->sg_table, &a->table);

	if (ret) {

		kfree(a);

		return -ENOMEM;

		return ret;

	}



	a->table = table;

	a->dev = attachment->dev;

	INIT_LIST_HEAD(&a->list);

	a->mapped = false;
@@ -118,8 +110,7 @@ static void system_heap_detach(struct dma_buf *dmabuf, 
	list_del(&a->list);

	mutex_unlock(&buffer->lock);



	sg_free_table(a->table);

	kfree(a->table);

	sg_free_table(&a->table);

	kfree(a);

}
@@ -127,7 +118,7 @@ static struct sg_table *system_heap_map_dma_buf(struct dma_buf_attachment *attac 
						enum dma_data_direction direction)

{

	struct dma_heap_attachment *a = attachment->priv;

	struct sg_table *table = a->table;

	struct sg_table *table = &a->table;

	int ret;



	ret = dma_map_sgtable(attachment->dev, table, direction, 0);
@@ -162,7 +153,7 @@ static int system_heap_dma_buf_begin_cpu_access(struct dma_buf *dmabuf, 
	list_for_each_entry(a, &buffer->attachments, list) {

		if (!a->mapped)

			continue;

		dma_sync_sgtable_for_cpu(a->dev, a->table, direction);

		dma_sync_sgtable_for_cpu(a->dev, &a->table, direction);

	}

	mutex_unlock(&buffer->lock);
@@ -183,7 +174,7 @@ static int system_heap_dma_buf_end_cpu_access(struct dma_buf *dmabuf, 
	list_for_each_entry(a, &buffer->attachments, list) {

		if (!a->mapped)

			continue;

		dma_sync_sgtable_for_device(a->dev, a->table, direction);

		dma_sync_sgtable_for_device(a->dev, &a->table, direction);

	}

	mutex_unlock(&buffer->lock);