dma-buf: heaps: add Linaro secure dmabuf heap support

add Linaro secure heap bindings: linaro,secure-heap
use genalloc to allocate/free buffer from buffer pool.
buffer pool info is from dts.
use sg_table instore the allocated memory info, the length of sg_table is 1.
implement secure_heap_buf_ops to implement buffer share in difference device:
1. Userspace passes this fd to all drivers it wants this buffer
to share with: First the filedescriptor is converted to a &dma_buf using
dma_buf_get(). Then the buffer is attached to the device using dma_buf_attach().
2. Once the buffer is attached to all devices userspace can initiate DMA
access to the shared buffer. In the kernel this is done by calling dma_buf_map_attachment()
3. get sg_table with dma_buf_map_attachment in difference device.

Signed-off-by: Olivier Masse <[email protected]>

Author: omasse-nxp

drivers/dma-buf/heaps/Kconfig

@@ -1,8 +1,12 @@
-config DMABUF_HEAPS_DEFERRED_FREE
-	tristate
+menuconfig DMABUF_HEAPS_DEFERRED_FREE
+	bool "DMA-BUF heaps deferred-free library"
+	help
+	  Choose this option to enable the DMA-BUF heaps deferred-free library.
 
-config DMABUF_HEAPS_PAGE_POOL
-	tristate
+menuconfig DMABUF_HEAPS_PAGE_POOL
+	bool "DMA-BUF heaps page-pool library"
+	help
+	  Choose this option to enable the DMA-BUF heaps page-pool library.
 
 config DMABUF_HEAPS_SYSTEM
 	bool "DMA-BUF System Heap"
@@ -18,3 +22,12 @@ 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_SECURE
+	tristate "DMA-BUF Secure Heap"
+	depends on DMABUF_HEAPS && DMABUF_HEAPS_DEFERRED_FREE
+	help
+	  Choose this option to enable the secure dmabuf heap. The secure heap
+	  pools are defined according to the DT. Heaps are allocated
+	  in the pools using gen allocater.
+	  If in doubt, say Y.

drivers/dma-buf/heaps/Makefile

@@ -3,3 +3,4 @@ obj-$(CONFIG_DMABUF_HEAPS_DEFERRED_FREE) += deferred-free-helper.o
 obj-$(CONFIG_DMABUF_HEAPS_PAGE_POOL)	+= page_pool.o
 obj-$(CONFIG_DMABUF_HEAPS_SYSTEM)	+= system_heap.o
 obj-$(CONFIG_DMABUF_HEAPS_CMA)		+= cma_heap.o
+obj-$(CONFIG_DMABUF_HEAPS_SECURE)	+= secure_heap.o