3 files changed, 56 insertions, 33 deletions

diff --git a/drivers/dma-buf/heaps/Kconfig b/drivers/dma-buf/heaps/Kconfig
index a5eef06c4226..bb369b38b001 100644
--- a/drivers/dma-buf/heaps/Kconfig
+++ b/drivers/dma-buf/heaps/Kconfig
@@ -12,3 +12,13 @@ config DMABUF_HEAPS_CMA
 	  Choose this option to enable dma-buf CMA heap. This heap is backed
 	  by the Contiguous Memory Allocator (CMA). If your system has these
 	  regions, you should say Y here.
+
+config DMABUF_HEAPS_CMA_LEGACY
+	bool "Legacy DMA-BUF CMA Heap"
+	default y
+	depends on DMABUF_HEAPS_CMA
+	help
+	  Add a duplicate CMA-backed dma-buf heap with legacy naming derived
+	  from the CMA area's devicetree node, or "reserved" if the area is not
+	  defined in the devicetree. This uses the same underlying allocator as
+	  CONFIG_DMABUF_HEAPS_CMA.
diff --git a/drivers/dma-buf/heaps/cma_heap.c b/drivers/dma-buf/heaps/cma_heap.c
index 9512d050563a..0df007111975 100644
--- a/drivers/dma-buf/heaps/cma_heap.c
+++ b/drivers/dma-buf/heaps/cma_heap.c
@@ -9,6 +9,9 @@
  * Copyright (C) 2019 Texas Instruments Incorporated - http://www.ti.com/
  *	Andrew F. Davis <afd@ti.com>
  */
+
+#define pr_fmt(fmt) "cma_heap: " fmt
+
 #include <linux/cma.h>
 #include <linux/dma-buf.h>
 #include <linux/dma-heap.h>
@@ -22,6 +25,7 @@
 #include <linux/slab.h>
 #include <linux/vmalloc.h>
 
+#define DEFAULT_CMA_NAME "default_cma_region"
 
 struct cma_heap {
 	struct dma_heap *heap;
@@ -366,17 +370,17 @@ static const struct dma_heap_ops cma_heap_ops = {
 	.allocate = cma_heap_allocate,
 };
 
-static int __init __add_cma_heap(struct cma *cma, void *data)
+static int __init __add_cma_heap(struct cma *cma, const char *name)
 {
-	struct cma_heap *cma_heap;
 	struct dma_heap_export_info exp_info;
+	struct cma_heap *cma_heap;
 
 	cma_heap = kzalloc(sizeof(*cma_heap), GFP_KERNEL);
 	if (!cma_heap)
 		return -ENOMEM;
 	cma_heap->cma = cma;
 
-	exp_info.name = cma_get_name(cma);
+	exp_info.name = name;
 	exp_info.ops = &cma_heap_ops;
 	exp_info.priv = cma_heap;
 
@@ -394,12 +398,30 @@ static int __init __add_cma_heap(struct cma *cma, void *data)
 static int __init add_default_cma_heap(void)
 {
 	struct cma *default_cma = dev_get_cma_area(NULL);
-	int ret = 0;
+	const char *legacy_cma_name;
+	int ret;
 
-	if (default_cma)
-		ret = __add_cma_heap(default_cma, NULL);
+	if (!default_cma)
+		return 0;
 
-	return ret;
+	ret = __add_cma_heap(default_cma, DEFAULT_CMA_NAME);
+	if (ret)
+		return ret;
+
+	if (IS_ENABLED(CONFIG_DMABUF_HEAPS_CMA_LEGACY)) {
+		legacy_cma_name = cma_get_name(default_cma);
+		if (!strcmp(legacy_cma_name, DEFAULT_CMA_NAME)) {
+			pr_warn("legacy name and default name are the same, skipping legacy heap\n");
+			return 0;
+		}
+
+		ret = __add_cma_heap(default_cma, legacy_cma_name);
+		if (ret)
+			pr_warn("failed to add legacy heap: %pe\n",
+				ERR_PTR(ret));
+	}
+
+	return 0;
 }
 module_init(add_default_cma_heap);
 MODULE_DESCRIPTION("DMA-BUF CMA Heap");
diff --git a/drivers/dma-buf/heaps/system_heap.c b/drivers/dma-buf/heaps/system_heap.c
index 82b1b714300d..bbe7881f1360 100644
--- a/drivers/dma-buf/heaps/system_heap.c
+++ b/drivers/dma-buf/heaps/system_heap.c
@@ -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);