The CMA heap's name in devtmpfs can vary depending on how the heap is
defined. Its name defaults to "reserved", but if a CMA area is defined
in the devicetree, the heap takes on the devicetree node's name, such as
"default-pool" or "linux,cma". To simplify naming, just name it
"default_cma", and keep a legacy node in place backed by the same
underlying structure for backwards compatibility.
Signed-off-by: Jared Kangas <jkan...@redhat.com>
---
Documentation/userspace-api/dma-buf-heaps.rst | 11 +++++++----
drivers/dma-buf/heaps/Kconfig | 10 ++++++++++
drivers/dma-buf/heaps/cma_heap.c | 14 +++++++++++++-
3 files changed, 30 insertions(+), 5 deletions(-)
diff --git a/Documentation/userspace-api/dma-buf-heaps.rst
b/Documentation/userspace-api/dma-buf-heaps.rst
index 535f49047ce64..577de813ba461 100644
--- a/Documentation/userspace-api/dma-buf-heaps.rst
+++ b/Documentation/userspace-api/dma-buf-heaps.rst
@@ -19,7 +19,10 @@ following heaps:
- The ``cma`` heap allocates physically contiguous, cacheable,
buffers. Only present if a CMA region is present. Such a region is
usually created either through the kernel commandline through the
- `cma` parameter, a memory region Device-Tree node with the
- `linux,cma-default` property set, or through the `CMA_SIZE_MBYTES` or
- `CMA_SIZE_PERCENTAGE` Kconfig options. Depending on the platform, it
- might be called ``reserved``, ``linux,cma``, or ``default-pool``.
+ ``cma`` parameter, a memory region Device-Tree node with the
+ ``linux,cma-default`` property set, or through the ``CMA_SIZE_MBYTES`` or
+ ``CMA_SIZE_PERCENTAGE`` Kconfig options. The heap's name in devtmpfs is
+ ``default_cma``. For backwards compatibility, when the
+ ``DMABUF_HEAPS_CMA_LEGACY`` Kconfig option is set, a duplicate node is
+ created following legacy naming conventions; the legacy name might be
+ ``reserved``, ``linux,cma``, or ``default-pool``.
diff --git a/drivers/dma-buf/heaps/Kconfig b/drivers/dma-buf/heaps/Kconfig
index a5eef06c42264..83f3770fa820a 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 "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 e998d8ccd1dc6..cd742c961190d 100644
--- a/drivers/dma-buf/heaps/cma_heap.c
+++ b/drivers/dma-buf/heaps/cma_heap.c
@@ -22,6 +22,7 @@
#include <linux/slab.h>
#include <linux/vmalloc.h>
+#define DEFAULT_CMA_NAME "default_cma"
struct cma_heap {
struct dma_heap *heap;
@@ -394,15 +395,26 @@ static int __init __add_cma_heap(struct cma *cma, const
char *name)
static int __init add_default_cma_heap(void)
{
struct cma *default_cma = dev_get_cma_area(NULL);
+ const char *legacy_cma_name;
int ret;
if (!default_cma)
return 0;
- ret = __add_cma_heap(default_cma, cma_get_name(default_cma));
+ ret = __add_cma_heap(default_cma, DEFAULT_CMA_NAME);
if (ret)
return ret;
+ legacy_cma_name = cma_get_name(default_cma);
+
+ if (IS_ENABLED(CONFIG_DMABUF_HEAPS_CMA_LEGACY) &&
+ strcmp(legacy_cma_name, DEFAULT_CMA_NAME)) {
+ ret = __add_cma_heap(default_cma, legacy_cma_name);
+ if (ret)
+ pr_warn("cma_heap: failed to add legacy heap: %pe\n",
+ ERR_PTR(-ret));
+ }
+
return 0;
}
module_init(add_default_cma_heap);
--
2.49.0
