// 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->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 ret; } 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");