[PATCH RFC 10/12] dma-buf: cma: Account for allocations in dmem cgroup

[Maxime Ripard]

Now that we have a DMEM region per CMA region, we can track the
allocations of the CMA heap through DMEM.

Signed-off-by: Maxime Ripard <mripard@xxxxxxxxxx>
---
 drivers/dma-buf/heaps/cma_heap.c | 18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

diff --git a/drivers/dma-buf/heaps/cma_heap.c b/drivers/dma-buf/heaps/cma_heap.c
index 9512d050563a9ad0a735230c4870c3d3b3b01b25..4951c41db3ba0cbd903b6d62787f51b83f4a1e7e 100644
--- a/drivers/dma-buf/heaps/cma_heap.c
+++ b/drivers/dma-buf/heaps/cma_heap.c
@@ -7,10 +7,11 @@
  *
  * Also utilizing parts of Andrew Davis' SRAM heap:
  * Copyright (C) 2019 Texas Instruments Incorporated - http://www.ti.com/
  *	Andrew F. Davis <afd@xxxxxx>
  */
+#include <linux/cgroup_dmem.h>
 #include <linux/cma.h>
 #include <linux/dma-buf.h>
 #include <linux/dma-heap.h>
 #include <linux/dma-map-ops.h>
 #include <linux/err.h>
@@ -276,23 +277,31 @@ static struct dma_buf *cma_heap_allocate(struct dma_heap *heap,
 					 unsigned long len,
 					 u32 fd_flags,
 					 u64 heap_flags)
 {
 	struct cma_heap *cma_heap = dma_heap_get_drvdata(heap);
+	struct dmem_cgroup_pool_state *pool;
 	struct cma_heap_buffer *buffer;
 	DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
 	size_t size = PAGE_ALIGN(len);
 	pgoff_t pagecount = size >> PAGE_SHIFT;
 	unsigned long align = get_order(size);
 	struct page *cma_pages;
 	struct dma_buf *dmabuf;
 	int ret = -ENOMEM;
 	pgoff_t pg;
 
+	ret = dmem_cgroup_try_charge(cma_get_dmem_cgroup_region(cma_heap->cma),
+				     size, &pool, NULL);
+	if (ret)
+		return ERR_PTR(ret);
+
 	buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
-	if (!buffer)
-		return ERR_PTR(-ENOMEM);
+	if (!buffer) {
+		ret = -ENOMEM;
+		goto uncharge_cgroup;
+	}
 
 	INIT_LIST_HEAD(&buffer->attachments);
 	mutex_init(&buffer->lock);
 	buffer->len = size;
 
@@ -348,18 +357,23 @@ static struct dma_buf *cma_heap_allocate(struct dma_heap *heap,
 	dmabuf = dma_buf_export(&exp_info);
 	if (IS_ERR(dmabuf)) {
 		ret = PTR_ERR(dmabuf);
 		goto free_pages;
 	}
+
+	dmabuf->cgroup_pool = pool;
+
 	return dmabuf;
 
 free_pages:
 	kfree(buffer->pages);
 free_cma:
 	cma_release(cma_heap->cma, cma_pages, pagecount);
 free_buffer:
 	kfree(buffer);
+uncharge_cgroup:
+	dmem_cgroup_uncharge(pool, len);
 
 	return ERR_PTR(ret);
 }
 
 static const struct dma_heap_ops cma_heap_ops = {

-- 
2.48.1