From 47a32f9c12266d450b92089148c6039591bd9909 Mon Sep 17 00:00:00 2001 From: John Stultz Date: Mon, 21 Oct 2019 19:03:08 +0000 Subject: [PATCH] dma-buf: heaps: Add system heap to dmabuf heaps This patch adds system heap to the dma-buf heaps framework. This allows applications to get a page-allocator backed dma-buf for non-contiguous memory. This code is an evolution of the Android ION implementation, so thanks to its original authors and maintainters: Rebecca Schultz Zavin, Colin Cross, Laura Abbott, and others! Cc: Laura Abbott Cc: Benjamin Gaignard Cc: Sumit Semwal Cc: Liam Mark Cc: Pratik Patel Cc: Brian Starkey Cc: Vincent Donnefort Cc: Sudipto Paul Cc: Andrew F. Davis Cc: Christoph Hellwig Cc: Chenbo Feng Cc: Alistair Strachan Cc: Hridya Valsaraju Cc: Hillf Danton Cc: dri-devel@lists.freedesktop.org Reviewed-by: Benjamin Gaignard Reviewed-by: Brian Starkey Acked-by: Laura Abbott Tested-by: Ayan Kumar Halder Signed-off-by: John Stultz Signed-off-by: Sumit Semwal Link: https://patchwork.freedesktop.org/patch/msgid/20191021190310.85221-4-john.stultz@linaro.org --- drivers/dma-buf/Kconfig | 2 + drivers/dma-buf/heaps/Kconfig | 6 ++ drivers/dma-buf/heaps/Makefile | 1 + drivers/dma-buf/heaps/system_heap.c | 124 ++++++++++++++++++++++++++++ 4 files changed, 133 insertions(+) create mode 100644 drivers/dma-buf/heaps/Kconfig create mode 100644 drivers/dma-buf/heaps/system_heap.c diff --git a/drivers/dma-buf/Kconfig b/drivers/dma-buf/Kconfig index bffa58fc3e6e..0613bb7770f5 100644 --- a/drivers/dma-buf/Kconfig +++ b/drivers/dma-buf/Kconfig @@ -53,4 +53,6 @@ menuconfig DMABUF_HEAPS allows userspace to allocate dma-bufs that can be shared between drivers. +source "drivers/dma-buf/heaps/Kconfig" + endmenu diff --git a/drivers/dma-buf/heaps/Kconfig b/drivers/dma-buf/heaps/Kconfig new file mode 100644 index 000000000000..205052744169 --- /dev/null +++ b/drivers/dma-buf/heaps/Kconfig @@ -0,0 +1,6 @@ +config DMABUF_HEAPS_SYSTEM + bool "DMA-BUF System Heap" + depends on DMABUF_HEAPS + help + Choose this option to enable the system dmabuf heap. The system heap + is backed by pages from the buddy allocator. If in doubt, say Y. diff --git a/drivers/dma-buf/heaps/Makefile b/drivers/dma-buf/heaps/Makefile index de49898112db..d1808eca2581 100644 --- a/drivers/dma-buf/heaps/Makefile +++ b/drivers/dma-buf/heaps/Makefile @@ -1,2 +1,3 @@ # SPDX-License-Identifier: GPL-2.0 obj-y += heap-helpers.o +obj-$(CONFIG_DMABUF_HEAPS_SYSTEM) += system_heap.o diff --git a/drivers/dma-buf/heaps/system_heap.c b/drivers/dma-buf/heaps/system_heap.c new file mode 100644 index 000000000000..455782efbb32 --- /dev/null +++ b/drivers/dma-buf/heaps/system_heap.c @@ -0,0 +1,124 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * DMABUF System heap exporter + * + * Copyright (C) 2011 Google, Inc. + * Copyright (C) 2019 Linaro Ltd. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "heap-helpers.h" + +struct dma_heap *sys_heap; + +static void system_heap_free(struct heap_helper_buffer *buffer) +{ + pgoff_t pg; + + for (pg = 0; pg < buffer->pagecount; pg++) + __free_page(buffer->pages[pg]); + kfree(buffer->pages); + kfree(buffer); +} + +static int system_heap_allocate(struct dma_heap *heap, + unsigned long len, + unsigned long fd_flags, + unsigned long heap_flags) +{ + struct heap_helper_buffer *helper_buffer; + struct dma_buf *dmabuf; + int ret = -ENOMEM; + pgoff_t pg; + + helper_buffer = kzalloc(sizeof(*helper_buffer), GFP_KERNEL); + if (!helper_buffer) + return -ENOMEM; + + init_heap_helper_buffer(helper_buffer, system_heap_free); + helper_buffer->flags = heap_flags; + helper_buffer->heap = heap; + helper_buffer->size = len; + + helper_buffer->pagecount = len / PAGE_SIZE; + helper_buffer->pages = kmalloc_array(helper_buffer->pagecount, + sizeof(*helper_buffer->pages), + GFP_KERNEL); + if (!helper_buffer->pages) { + ret = -ENOMEM; + goto err0; + } + + for (pg = 0; pg < helper_buffer->pagecount; pg++) { + /* + * Avoid trying to allocate memory if the process + * has been killed by by SIGKILL + */ + if (fatal_signal_pending(current)) + goto err1; + + helper_buffer->pages[pg] = alloc_page(GFP_KERNEL | __GFP_ZERO); + if (!helper_buffer->pages[pg]) + goto err1; + } + + /* create the dmabuf */ + dmabuf = heap_helper_export_dmabuf(helper_buffer, fd_flags); + if (IS_ERR(dmabuf)) { + ret = PTR_ERR(dmabuf); + goto err1; + } + + helper_buffer->dmabuf = dmabuf; + + ret = dma_buf_fd(dmabuf, fd_flags); + if (ret < 0) { + dma_buf_put(dmabuf); + /* just return, as put will call release and that will free */ + return ret; + } + + return ret; + +err1: + while (pg > 0) + __free_page(helper_buffer->pages[--pg]); + kfree(helper_buffer->pages); +err0: + kfree(helper_buffer); + + return -ENOMEM; +} + +static const struct dma_heap_ops system_heap_ops = { + .allocate = system_heap_allocate, +}; + +static int system_heap_create(void) +{ + struct dma_heap_export_info exp_info; + int ret = 0; + + exp_info.name = "system_heap"; + exp_info.ops = &system_heap_ops; + exp_info.priv = NULL; + + sys_heap = dma_heap_add(&exp_info); + if (IS_ERR(sys_heap)) + ret = PTR_ERR(sys_heap); + + return ret; +} +module_init(system_heap_create); +MODULE_LICENSE("GPL v2");