[Linaro-mm-sig] Re: [PATCH v4 2/7] dma-buf: heaps: Initialize a restricted heap

On Fri, Jan 12, 2024 at 05:20:09PM +0800, Yong Wu wrote:

Initialize a restricted heap. Currently just add a null heap, Prepare for the later patches.

Signed-off-by: Yong Wu yong.wu@mediatek.com

drivers/dma-buf/heaps/Kconfig | 9 ++++ drivers/dma-buf/heaps/Makefile | 3 +- drivers/dma-buf/heaps/restricted_heap.c | 67 +++++++++++++++++++++++++ drivers/dma-buf/heaps/restricted_heap.h | 22 ++++++++ 4 files changed, 100 insertions(+), 1 deletion(-) create mode 100644 drivers/dma-buf/heaps/restricted_heap.c create mode 100644 drivers/dma-buf/heaps/restricted_heap.h

diff --git a/drivers/dma-buf/heaps/Kconfig b/drivers/dma-buf/heaps/Kconfig index a5eef06c4226..e54506f480ea 100644 --- a/drivers/dma-buf/heaps/Kconfig +++ b/drivers/dma-buf/heaps/Kconfig @@ -12,3 +12,12 @@ 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_RESTRICTED

• bool "DMA-BUF Restricted Heap"
• depends on DMABUF_HEAPS
• help

•  Choose this option to enable dma-buf restricted heap. The purpose of this
  

•  heap is to manage buffers that are inaccessible to the kernel and user space.
  

•  There may be several ways to restrict it, for example it may be encrypted or
  

•  protected by a TEE or hypervisor. If in doubt, say N.
  

diff --git a/drivers/dma-buf/heaps/Makefile b/drivers/dma-buf/heaps/Makefile index 974467791032..a2437c1817e2 100644 --- a/drivers/dma-buf/heaps/Makefile +++ b/drivers/dma-buf/heaps/Makefile @@ -1,3 +1,4 @@ # SPDX-License-Identifier: GPL-2.0 -obj-$(CONFIG_DMABUF_HEAPS_SYSTEM) += system_heap.o obj-$(CONFIG_DMABUF_HEAPS_CMA) += cma_heap.o +obj-$(CONFIG_DMABUF_HEAPS_RESTRICTED) += restricted_heap.o +obj-$(CONFIG_DMABUF_HEAPS_SYSTEM) += system_heap.o diff --git a/drivers/dma-buf/heaps/restricted_heap.c b/drivers/dma-buf/heaps/restricted_heap.c new file mode 100644 index 000000000000..fd7c82abd42e --- /dev/null +++ b/drivers/dma-buf/heaps/restricted_heap.c @@ -0,0 +1,67 @@ +// SPDX-License-Identifier: GPL-2.0 +/*

• • DMABUF restricted heap exporter
• • Copyright (C) 2024 MediaTek Inc.
• */

+#include <linux/dma-buf.h> +#include <linux/dma-heap.h> +#include <linux/err.h> +#include <linux/slab.h>

+#include "restricted_heap.h"

+static struct dma_buf * +restricted_heap_allocate(struct dma_heap *heap, unsigned long size,

• 	 unsigned long fd_flags, unsigned long heap_flags)
  

+{

• struct restricted_buffer *restricted_buf;
• DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
• struct dma_buf *dmabuf;
• int ret;
• restricted_buf = kzalloc(sizeof(*restricted_buf), GFP_KERNEL);
• if (!restricted_buf)

• return ERR_PTR(-ENOMEM);
  

• restricted_buf->size = ALIGN(size, PAGE_SIZE);
• restricted_buf->heap = heap;
• exp_info.exp_name = dma_heap_get_name(heap);
• exp_info.size = restricted_buf->size;
• exp_info.flags = fd_flags;
• exp_info.priv = restricted_buf;
• dmabuf = dma_buf_export(&exp_info);
• if (IS_ERR(dmabuf)) {

• ret = PTR_ERR(dmabuf);
  

• goto err_free_buf;
  

• }
• return dmabuf;

+err_free_buf:

• kfree(restricted_buf);
• return ERR_PTR(ret);

+}

+static const struct dma_heap_ops restricted_heap_ops = {

• .allocate = restricted_heap_allocate,

+};

+int restricted_heap_add(struct restricted_heap *rstrd_heap)

Nothing wrong, but what about shortening rstrd_heap throughout the patch set to "rheap", I would find that easier to read.

+{

• struct dma_heap_export_info exp_info;
• struct dma_heap *heap;
• exp_info.name = rstrd_heap->name;
• exp_info.ops = &restricted_heap_ops;
• exp_info.priv = (void *)rstrd_heap;
• heap = dma_heap_add(&exp_info);
• if (IS_ERR(heap))

• return PTR_ERR(heap);
  

• return 0;

+} +EXPORT_SYMBOL_GPL(restricted_heap_add); diff --git a/drivers/dma-buf/heaps/restricted_heap.h b/drivers/dma-buf/heaps/restricted_heap.h new file mode 100644 index 000000000000..443028f6ba3b --- /dev/null +++ b/drivers/dma-buf/heaps/restricted_heap.h @@ -0,0 +1,22 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/*

• • Restricted heap Header.
• • Copyright (C) 2024 MediaTek, Inc.
• */

+#ifndef _DMABUF_RESTRICTED_HEAP_H_ +#define _DMABUF_RESTRICTED_HEAP_H_

+struct restricted_buffer {

• struct dma_heap *heap;
• size_t size;

+};

+struct restricted_heap {

• const char *name;

+};

+int restricted_heap_add(struct restricted_heap *rstrd_heap);

+#endif

2.25.1