![Christoph Hellwig](/assets/img/avatar_default.png)
Merge dma-contiguous.h into dma-map-ops.h, after removing the comment describing the contiguous allocator into kernel/dma/contigous.c. Signed-off-by: Christoph Hellwig <hch@lst.de>
178 lines
4 KiB
C
178 lines
4 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* DMABUF CMA heap exporter
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*
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* Copyright (C) 2012, 2019 Linaro Ltd.
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* Author: <benjamin.gaignard@linaro.org> for ST-Ericsson.
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*/
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#include <linux/cma.h>
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#include <linux/device.h>
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#include <linux/dma-buf.h>
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#include <linux/dma-heap.h>
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#include <linux/dma-map-ops.h>
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#include <linux/err.h>
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#include <linux/errno.h>
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#include <linux/highmem.h>
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#include <linux/module.h>
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#include <linux/slab.h>
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#include <linux/scatterlist.h>
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#include <linux/sched/signal.h>
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#include "heap-helpers.h"
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struct cma_heap {
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struct dma_heap *heap;
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struct cma *cma;
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};
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static void cma_heap_free(struct heap_helper_buffer *buffer)
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{
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struct cma_heap *cma_heap = dma_heap_get_drvdata(buffer->heap);
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unsigned long nr_pages = buffer->pagecount;
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struct page *cma_pages = buffer->priv_virt;
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/* free page list */
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kfree(buffer->pages);
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/* release memory */
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cma_release(cma_heap->cma, cma_pages, nr_pages);
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kfree(buffer);
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}
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/* dmabuf heap CMA operations functions */
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static int cma_heap_allocate(struct dma_heap *heap,
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unsigned long len,
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unsigned long fd_flags,
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unsigned long heap_flags)
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{
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struct cma_heap *cma_heap = dma_heap_get_drvdata(heap);
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struct heap_helper_buffer *helper_buffer;
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struct page *cma_pages;
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size_t size = PAGE_ALIGN(len);
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unsigned long nr_pages = size >> PAGE_SHIFT;
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unsigned long align = get_order(size);
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struct dma_buf *dmabuf;
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int ret = -ENOMEM;
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pgoff_t pg;
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if (align > CONFIG_CMA_ALIGNMENT)
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align = CONFIG_CMA_ALIGNMENT;
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helper_buffer = kzalloc(sizeof(*helper_buffer), GFP_KERNEL);
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if (!helper_buffer)
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return -ENOMEM;
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init_heap_helper_buffer(helper_buffer, cma_heap_free);
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helper_buffer->heap = heap;
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helper_buffer->size = len;
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cma_pages = cma_alloc(cma_heap->cma, nr_pages, align, false);
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if (!cma_pages)
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goto free_buf;
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if (PageHighMem(cma_pages)) {
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unsigned long nr_clear_pages = nr_pages;
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struct page *page = cma_pages;
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while (nr_clear_pages > 0) {
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void *vaddr = kmap_atomic(page);
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memset(vaddr, 0, PAGE_SIZE);
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kunmap_atomic(vaddr);
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/*
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* Avoid wasting time zeroing memory if the process
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* has been killed by by SIGKILL
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*/
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if (fatal_signal_pending(current))
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goto free_cma;
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page++;
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nr_clear_pages--;
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}
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} else {
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memset(page_address(cma_pages), 0, size);
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}
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helper_buffer->pagecount = nr_pages;
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helper_buffer->pages = kmalloc_array(helper_buffer->pagecount,
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sizeof(*helper_buffer->pages),
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GFP_KERNEL);
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if (!helper_buffer->pages) {
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ret = -ENOMEM;
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goto free_cma;
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}
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for (pg = 0; pg < helper_buffer->pagecount; pg++)
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helper_buffer->pages[pg] = &cma_pages[pg];
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/* create the dmabuf */
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dmabuf = heap_helper_export_dmabuf(helper_buffer, fd_flags);
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if (IS_ERR(dmabuf)) {
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ret = PTR_ERR(dmabuf);
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goto free_pages;
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}
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helper_buffer->dmabuf = dmabuf;
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helper_buffer->priv_virt = cma_pages;
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ret = dma_buf_fd(dmabuf, fd_flags);
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if (ret < 0) {
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dma_buf_put(dmabuf);
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/* just return, as put will call release and that will free */
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return ret;
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}
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return ret;
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free_pages:
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kfree(helper_buffer->pages);
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free_cma:
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cma_release(cma_heap->cma, cma_pages, nr_pages);
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free_buf:
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kfree(helper_buffer);
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return ret;
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}
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static const struct dma_heap_ops cma_heap_ops = {
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.allocate = cma_heap_allocate,
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};
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static int __add_cma_heap(struct cma *cma, void *data)
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{
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struct cma_heap *cma_heap;
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struct dma_heap_export_info exp_info;
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cma_heap = kzalloc(sizeof(*cma_heap), GFP_KERNEL);
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if (!cma_heap)
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return -ENOMEM;
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cma_heap->cma = cma;
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exp_info.name = cma_get_name(cma);
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exp_info.ops = &cma_heap_ops;
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exp_info.priv = cma_heap;
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cma_heap->heap = dma_heap_add(&exp_info);
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if (IS_ERR(cma_heap->heap)) {
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int ret = PTR_ERR(cma_heap->heap);
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kfree(cma_heap);
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return ret;
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}
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return 0;
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}
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static int add_default_cma_heap(void)
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{
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struct cma *default_cma = dev_get_cma_area(NULL);
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int ret = 0;
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if (default_cma)
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ret = __add_cma_heap(default_cma, NULL);
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return ret;
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}
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module_init(add_default_cma_heap);
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MODULE_DESCRIPTION("DMA-BUF CMA Heap");
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MODULE_LICENSE("GPL v2");
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