From mboxrd@z Thu Jan 1 00:00:00 1970 From: John Stultz Subject: [RFC][PATCH 4/5 v2] dma-buf: heaps: Add CMA heap to dmabuf heapss Date: Tue, 5 Mar 2019 12:54:32 -0800 Message-ID: <1551819273-640-5-git-send-email-john.stultz@linaro.org> References: <1551819273-640-1-git-send-email-john.stultz@linaro.org> Return-path: In-Reply-To: <1551819273-640-1-git-send-email-john.stultz@linaro.org> Sender: linux-kernel-owner@vger.kernel.org To: lkml Cc: John Stultz , Laura Abbott , Benjamin Gaignard , Greg KH , Sumit Semwal , Liam Mark , Brian Starkey , "Andrew F . Davis" , Chenbo Feng , Alistair Strachan , dri-devel@lists.freedesktop.org List-Id: dri-devel@lists.freedesktop.org This adds a CMA heap, which allows userspace to allocate a dma-buf of contiguous memory out of a CMA region. This code is an evolution of the Android ION implementation, so thanks to its original author and maintainters: Benjamin Gaignard, Laura Abbott, and others! Cc: Laura Abbott Cc: Benjamin Gaignard Cc: Greg KH Cc: Sumit Semwal Cc: Liam Mark Cc: Brian Starkey Cc: Andrew F. Davis Cc: Chenbo Feng Cc: Alistair Strachan Cc: dri-devel@lists.freedesktop.org Signed-off-by: John Stultz --- v2: * Switch allocate to return dmabuf fd * Simplify init code * Checkpatch fixups --- drivers/dma-buf/heaps/Kconfig | 8 ++ drivers/dma-buf/heaps/Makefile | 1 + drivers/dma-buf/heaps/cma_heap.c | 164 +++++++++++++++++++++++++++++++++++++++ 3 files changed, 173 insertions(+) create mode 100644 drivers/dma-buf/heaps/cma_heap.c diff --git a/drivers/dma-buf/heaps/Kconfig b/drivers/dma-buf/heaps/Kconfig index 2050527..a5eef06 100644 --- a/drivers/dma-buf/heaps/Kconfig +++ b/drivers/dma-buf/heaps/Kconfig @@ -4,3 +4,11 @@ config DMABUF_HEAPS_SYSTEM 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. + +config DMABUF_HEAPS_CMA + bool "DMA-BUF CMA Heap" + depends on DMABUF_HEAPS && DMA_CMA + help + 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. diff --git a/drivers/dma-buf/heaps/Makefile b/drivers/dma-buf/heaps/Makefile index d1808ec..6e54cde 100644 --- a/drivers/dma-buf/heaps/Makefile +++ b/drivers/dma-buf/heaps/Makefile @@ -1,3 +1,4 @@ # SPDX-License-Identifier: GPL-2.0 obj-y += heap-helpers.o obj-$(CONFIG_DMABUF_HEAPS_SYSTEM) += system_heap.o +obj-$(CONFIG_DMABUF_HEAPS_CMA) += cma_heap.o diff --git a/drivers/dma-buf/heaps/cma_heap.c b/drivers/dma-buf/heaps/cma_heap.c new file mode 100644 index 0000000..33c18ec --- /dev/null +++ b/drivers/dma-buf/heaps/cma_heap.c @@ -0,0 +1,164 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * DMABUF CMA heap exporter + * + * Copyright (C) 2012, 2019 Linaro Ltd. + * Author: for ST-Ericsson. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "heap-helpers.h" + +struct cma_heap { + struct dma_heap heap; + struct cma *cma; +}; + + +#define to_cma_heap(x) container_of(x, struct cma_heap, heap) + + +static void cma_heap_free(struct heap_helper_buffer *buffer) +{ + struct cma_heap *cma_heap = to_cma_heap(buffer->heap_buffer.heap); + struct page *pages = buffer->priv_virt; + unsigned long nr_pages; + + nr_pages = PAGE_ALIGN(buffer->heap_buffer.size) >> PAGE_SHIFT; + + /* release memory */ + cma_release(cma_heap->cma, pages, nr_pages); + /* release sg table */ + sg_free_table(buffer->sg_table); + kfree(buffer->sg_table); + kfree(buffer); +} + +/* dmabuf heap CMA operations functions */ +static int cma_heap_allocate(struct dma_heap *heap, + unsigned long len, + unsigned long flags) +{ + struct cma_heap *cma_heap = to_cma_heap(heap); + struct heap_helper_buffer *helper_buffer; + struct sg_table *table; + struct page *pages; + size_t size = PAGE_ALIGN(len); + unsigned long nr_pages = size >> PAGE_SHIFT; + unsigned long align = get_order(size); + DEFINE_DMA_BUF_EXPORT_INFO(exp_info); + struct dma_buf *dmabuf; + int ret = -ENOMEM; + + if (align > CONFIG_CMA_ALIGNMENT) + align = CONFIG_CMA_ALIGNMENT; + + helper_buffer = kzalloc(sizeof(*helper_buffer), GFP_KERNEL); + if (!helper_buffer) + return -ENOMEM; + + INIT_HEAP_HELPER_BUFFER(helper_buffer, cma_heap_free); + helper_buffer->heap_buffer.flags = flags; + helper_buffer->heap_buffer.heap = heap; + helper_buffer->heap_buffer.size = len; + + + pages = cma_alloc(cma_heap->cma, nr_pages, align, false); + if (!pages) + goto free_buf; + + if (PageHighMem(pages)) { + unsigned long nr_clear_pages = nr_pages; + struct page *page = pages; + + while (nr_clear_pages > 0) { + void *vaddr = kmap_atomic(page); + + memset(vaddr, 0, PAGE_SIZE); + kunmap_atomic(vaddr); + page++; + nr_clear_pages--; + } + } else { + memset(page_address(pages), 0, size); + } + + table = kmalloc(sizeof(*table), GFP_KERNEL); + if (!table) + goto free_cma; + + ret = sg_alloc_table(table, 1, GFP_KERNEL); + if (ret) + goto free_table; + + sg_set_page(table->sgl, pages, size, 0); + + /* create the dmabuf */ + exp_info.ops = &heap_helper_ops; + exp_info.size = len; + exp_info.flags = O_RDWR; + exp_info.priv = &helper_buffer->heap_buffer; + dmabuf = dma_buf_export(&exp_info); + if (IS_ERR(dmabuf)) { + ret = PTR_ERR(dmabuf); + goto free_table; + } + + helper_buffer->heap_buffer.dmabuf = dmabuf; + helper_buffer->priv_virt = pages; + helper_buffer->sg_table = table; + + ret = dma_buf_fd(dmabuf, O_CLOEXEC); + if (ret < 0) { + dma_buf_put(dmabuf); + /* just return, as put will call release and that will free */ + return ret; + } + + return ret; +free_table: + kfree(table); +free_cma: + cma_release(cma_heap->cma, pages, nr_pages); +free_buf: + kfree(helper_buffer); + return ret; +} + +static struct dma_heap_ops cma_heap_ops = { + .allocate = cma_heap_allocate, +}; + +static int __add_cma_heaps(struct cma *cma, void *data) +{ + struct cma_heap *cma_heap; + + cma_heap = kzalloc(sizeof(*cma_heap), GFP_KERNEL); + + if (!cma_heap) + return -ENOMEM; + + cma_heap->heap.name = cma_get_name(cma); + cma_heap->heap.ops = &cma_heap_ops; + cma_heap->cma = cma; + + dma_heap_add(&cma_heap->heap); + + return 0; +} + +static int add_cma_heaps(void) +{ + cma_for_each_area(__add_cma_heaps, NULL); + return 0; +} +device_initcall(add_cma_heaps); -- 2.7.4