diff options
Diffstat (limited to 'drivers/dma-buf/heaps/cma_heap.c')
| -rw-r--r-- | drivers/dma-buf/heaps/cma_heap.c | 177 |
1 files changed, 177 insertions, 0 deletions
diff --git a/drivers/dma-buf/heaps/cma_heap.c b/drivers/dma-buf/heaps/cma_heap.c new file mode 100644 index 000000000..e55384dc1 --- /dev/null +++ b/drivers/dma-buf/heaps/cma_heap.c @@ -0,0 +1,177 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * DMABUF CMA heap exporter + * + * Copyright (C) 2012, 2019 Linaro Ltd. + * Author: <benjamin.gaignard@linaro.org> for ST-Ericsson. + */ + +#include <linux/cma.h> +#include <linux/device.h> +#include <linux/dma-buf.h> +#include <linux/dma-heap.h> +#include <linux/dma-map-ops.h> +#include <linux/err.h> +#include <linux/errno.h> +#include <linux/highmem.h> +#include <linux/module.h> +#include <linux/slab.h> +#include <linux/scatterlist.h> +#include <linux/sched/signal.h> + +#include "heap-helpers.h" + +struct cma_heap { + struct dma_heap *heap; + struct cma *cma; +}; + +static void cma_heap_free(struct heap_helper_buffer *buffer) +{ + struct cma_heap *cma_heap = dma_heap_get_drvdata(buffer->heap); + unsigned long nr_pages = buffer->pagecount; + struct page *cma_pages = buffer->priv_virt; + + /* free page list */ + kfree(buffer->pages); + /* release memory */ + cma_release(cma_heap->cma, cma_pages, nr_pages); + kfree(buffer); +} + +/* dmabuf heap CMA operations functions */ +static int cma_heap_allocate(struct dma_heap *heap, + unsigned long len, + unsigned long fd_flags, + unsigned long heap_flags) +{ + struct cma_heap *cma_heap = dma_heap_get_drvdata(heap); + struct heap_helper_buffer *helper_buffer; + struct page *cma_pages; + size_t size = PAGE_ALIGN(len); + unsigned long nr_pages = size >> PAGE_SHIFT; + unsigned long align = get_order(size); + struct dma_buf *dmabuf; + int ret = -ENOMEM; + pgoff_t pg; + + 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 = heap; + helper_buffer->size = len; + + cma_pages = cma_alloc(cma_heap->cma, nr_pages, align, false); + if (!cma_pages) + goto free_buf; + + if (PageHighMem(cma_pages)) { + unsigned long nr_clear_pages = nr_pages; + struct page *page = cma_pages; + + while (nr_clear_pages > 0) { + void *vaddr = kmap_atomic(page); + + memset(vaddr, 0, PAGE_SIZE); + kunmap_atomic(vaddr); + /* + * Avoid wasting time zeroing memory if the process + * has been killed by by SIGKILL + */ + if (fatal_signal_pending(current)) + goto free_cma; + + page++; + nr_clear_pages--; + } + } else { + memset(page_address(cma_pages), 0, size); + } + + helper_buffer->pagecount = nr_pages; + helper_buffer->pages = kmalloc_array(helper_buffer->pagecount, + sizeof(*helper_buffer->pages), + GFP_KERNEL); + if (!helper_buffer->pages) { + ret = -ENOMEM; + goto free_cma; + } + + for (pg = 0; pg < helper_buffer->pagecount; pg++) + helper_buffer->pages[pg] = &cma_pages[pg]; + + /* create the dmabuf */ + dmabuf = heap_helper_export_dmabuf(helper_buffer, fd_flags); + if (IS_ERR(dmabuf)) { + ret = PTR_ERR(dmabuf); + goto free_pages; + } + + helper_buffer->dmabuf = dmabuf; + helper_buffer->priv_virt = cma_pages; + + 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; + +free_pages: + kfree(helper_buffer->pages); +free_cma: + cma_release(cma_heap->cma, cma_pages, nr_pages); +free_buf: + kfree(helper_buffer); + return ret; +} + +static const struct dma_heap_ops cma_heap_ops = { + .allocate = cma_heap_allocate, +}; + +static int __add_cma_heap(struct cma *cma, void *data) +{ + struct cma_heap *cma_heap; + struct dma_heap_export_info exp_info; + + cma_heap = kzalloc(sizeof(*cma_heap), GFP_KERNEL); + if (!cma_heap) + return -ENOMEM; + cma_heap->cma = cma; + + exp_info.name = cma_get_name(cma); + exp_info.ops = &cma_heap_ops; + exp_info.priv = cma_heap; + + cma_heap->heap = dma_heap_add(&exp_info); + if (IS_ERR(cma_heap->heap)) { + int ret = PTR_ERR(cma_heap->heap); + + kfree(cma_heap); + return ret; + } + + return 0; +} + +static int add_default_cma_heap(void) +{ + struct cma *default_cma = dev_get_cma_area(NULL); + int ret = 0; + + if (default_cma) + ret = __add_cma_heap(default_cma, NULL); + + return ret; +} +module_init(add_default_cma_heap); +MODULE_DESCRIPTION("DMA-BUF CMA Heap"); +MODULE_LICENSE("GPL v2"); |