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..c2ae19ba7d7e --- /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 rheap_ops = { + .allocate = restricted_heap_allocate, +}; + +int restricted_heap_add(struct restricted_heap *rheap) +{ + struct dma_heap_export_info exp_info; + struct dma_heap *heap; + + exp_info.name = rheap->name; + exp_info.ops = &rheap_ops; + exp_info.priv = (void *)rheap; + + 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..b448f77616ac --- /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 *rheap); + +#endif