408 lines
9.0 KiB
C
408 lines
9.0 KiB
C
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// 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, 2020 Linaro Ltd.
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* Author: <benjamin.gaignard@linaro.org> for ST-Ericsson.
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*
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* Also utilizing parts of Andrew Davis' SRAM heap:
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* Copyright (C) 2019 Texas Instruments Incorporated - http://www.ti.com/
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* Andrew F. Davis <afd@ti.com>
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*/
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#include <linux/cma.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/highmem.h>
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#include <linux/io.h>
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#include <linux/mm.h>
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#include <linux/module.h>
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#include <linux/scatterlist.h>
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#include <linux/slab.h>
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#include <linux/vmalloc.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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struct cma_heap_buffer {
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struct cma_heap *heap;
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struct list_head attachments;
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struct mutex lock;
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unsigned long len;
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struct page *cma_pages;
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struct page **pages;
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pgoff_t pagecount;
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int vmap_cnt;
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void *vaddr;
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};
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struct dma_heap_attachment {
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struct device *dev;
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struct sg_table table;
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struct list_head list;
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bool mapped;
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};
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static int cma_heap_attach(struct dma_buf *dmabuf,
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struct dma_buf_attachment *attachment)
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{
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struct cma_heap_buffer *buffer = dmabuf->priv;
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struct dma_heap_attachment *a;
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int ret;
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a = kzalloc(sizeof(*a), GFP_KERNEL);
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if (!a)
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return -ENOMEM;
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ret = sg_alloc_table_from_pages(&a->table, buffer->pages,
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buffer->pagecount, 0,
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buffer->pagecount << PAGE_SHIFT,
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GFP_KERNEL);
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if (ret) {
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kfree(a);
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return ret;
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}
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a->dev = attachment->dev;
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INIT_LIST_HEAD(&a->list);
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a->mapped = false;
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attachment->priv = a;
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mutex_lock(&buffer->lock);
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list_add(&a->list, &buffer->attachments);
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mutex_unlock(&buffer->lock);
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return 0;
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}
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static void cma_heap_detach(struct dma_buf *dmabuf,
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struct dma_buf_attachment *attachment)
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{
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struct cma_heap_buffer *buffer = dmabuf->priv;
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struct dma_heap_attachment *a = attachment->priv;
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mutex_lock(&buffer->lock);
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list_del(&a->list);
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mutex_unlock(&buffer->lock);
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sg_free_table(&a->table);
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kfree(a);
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}
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static struct sg_table *cma_heap_map_dma_buf(struct dma_buf_attachment *attachment,
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enum dma_data_direction direction)
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{
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struct dma_heap_attachment *a = attachment->priv;
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struct sg_table *table = &a->table;
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int ret;
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ret = dma_map_sgtable(attachment->dev, table, direction, 0);
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if (ret)
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return ERR_PTR(-ENOMEM);
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a->mapped = true;
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return table;
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}
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static void cma_heap_unmap_dma_buf(struct dma_buf_attachment *attachment,
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struct sg_table *table,
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enum dma_data_direction direction)
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{
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struct dma_heap_attachment *a = attachment->priv;
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a->mapped = false;
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dma_unmap_sgtable(attachment->dev, table, direction, 0);
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}
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static int cma_heap_dma_buf_begin_cpu_access(struct dma_buf *dmabuf,
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enum dma_data_direction direction)
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{
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struct cma_heap_buffer *buffer = dmabuf->priv;
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struct dma_heap_attachment *a;
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mutex_lock(&buffer->lock);
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if (buffer->vmap_cnt)
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invalidate_kernel_vmap_range(buffer->vaddr, buffer->len);
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list_for_each_entry(a, &buffer->attachments, list) {
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if (!a->mapped)
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continue;
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dma_sync_sgtable_for_cpu(a->dev, &a->table, direction);
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}
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mutex_unlock(&buffer->lock);
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return 0;
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}
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static int cma_heap_dma_buf_end_cpu_access(struct dma_buf *dmabuf,
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enum dma_data_direction direction)
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{
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struct cma_heap_buffer *buffer = dmabuf->priv;
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struct dma_heap_attachment *a;
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mutex_lock(&buffer->lock);
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if (buffer->vmap_cnt)
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flush_kernel_vmap_range(buffer->vaddr, buffer->len);
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list_for_each_entry(a, &buffer->attachments, list) {
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if (!a->mapped)
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continue;
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dma_sync_sgtable_for_device(a->dev, &a->table, direction);
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}
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mutex_unlock(&buffer->lock);
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return 0;
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}
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static vm_fault_t cma_heap_vm_fault(struct vm_fault *vmf)
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{
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struct vm_area_struct *vma = vmf->vma;
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struct cma_heap_buffer *buffer = vma->vm_private_data;
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if (vmf->pgoff > buffer->pagecount)
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return VM_FAULT_SIGBUS;
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vmf->page = buffer->pages[vmf->pgoff];
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get_page(vmf->page);
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return 0;
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}
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static const struct vm_operations_struct dma_heap_vm_ops = {
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.fault = cma_heap_vm_fault,
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};
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static int cma_heap_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma)
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{
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struct cma_heap_buffer *buffer = dmabuf->priv;
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if ((vma->vm_flags & (VM_SHARED | VM_MAYSHARE)) == 0)
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return -EINVAL;
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vma->vm_ops = &dma_heap_vm_ops;
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vma->vm_private_data = buffer;
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return 0;
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}
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static void *cma_heap_do_vmap(struct cma_heap_buffer *buffer)
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{
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void *vaddr;
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vaddr = vmap(buffer->pages, buffer->pagecount, VM_MAP, PAGE_KERNEL);
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if (!vaddr)
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return ERR_PTR(-ENOMEM);
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return vaddr;
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}
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static int cma_heap_vmap(struct dma_buf *dmabuf, struct iosys_map *map)
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{
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struct cma_heap_buffer *buffer = dmabuf->priv;
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void *vaddr;
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int ret = 0;
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mutex_lock(&buffer->lock);
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if (buffer->vmap_cnt) {
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buffer->vmap_cnt++;
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iosys_map_set_vaddr(map, buffer->vaddr);
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goto out;
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}
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vaddr = cma_heap_do_vmap(buffer);
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if (IS_ERR(vaddr)) {
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ret = PTR_ERR(vaddr);
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goto out;
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}
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buffer->vaddr = vaddr;
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buffer->vmap_cnt++;
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iosys_map_set_vaddr(map, buffer->vaddr);
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out:
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mutex_unlock(&buffer->lock);
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return ret;
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}
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static void cma_heap_vunmap(struct dma_buf *dmabuf, struct iosys_map *map)
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{
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struct cma_heap_buffer *buffer = dmabuf->priv;
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mutex_lock(&buffer->lock);
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if (!--buffer->vmap_cnt) {
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vunmap(buffer->vaddr);
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buffer->vaddr = NULL;
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}
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mutex_unlock(&buffer->lock);
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iosys_map_clear(map);
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}
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static void cma_heap_dma_buf_release(struct dma_buf *dmabuf)
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{
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struct cma_heap_buffer *buffer = dmabuf->priv;
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struct cma_heap *cma_heap = buffer->heap;
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if (buffer->vmap_cnt > 0) {
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WARN(1, "%s: buffer still mapped in the kernel\n", __func__);
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vunmap(buffer->vaddr);
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buffer->vaddr = NULL;
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}
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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, buffer->cma_pages, buffer->pagecount);
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kfree(buffer);
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}
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static const struct dma_buf_ops cma_heap_buf_ops = {
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.attach = cma_heap_attach,
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.detach = cma_heap_detach,
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.map_dma_buf = cma_heap_map_dma_buf,
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.unmap_dma_buf = cma_heap_unmap_dma_buf,
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.begin_cpu_access = cma_heap_dma_buf_begin_cpu_access,
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.end_cpu_access = cma_heap_dma_buf_end_cpu_access,
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.mmap = cma_heap_mmap,
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.vmap = cma_heap_vmap,
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.vunmap = cma_heap_vunmap,
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.release = cma_heap_dma_buf_release,
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};
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static struct dma_buf *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 cma_heap_buffer *buffer;
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DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
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size_t size = PAGE_ALIGN(len);
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pgoff_t pagecount = size >> PAGE_SHIFT;
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unsigned long align = get_order(size);
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struct page *cma_pages;
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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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buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
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if (!buffer)
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return ERR_PTR(-ENOMEM);
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INIT_LIST_HEAD(&buffer->attachments);
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mutex_init(&buffer->lock);
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buffer->len = size;
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if (align > CONFIG_CMA_ALIGNMENT)
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align = CONFIG_CMA_ALIGNMENT;
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cma_pages = cma_alloc(cma_heap->cma, pagecount, align, false);
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if (!cma_pages)
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goto free_buffer;
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/* Clear the cma pages */
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if (PageHighMem(cma_pages)) {
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unsigned long nr_clear_pages = pagecount;
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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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buffer->pages = kmalloc_array(pagecount, sizeof(*buffer->pages), GFP_KERNEL);
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if (!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 < pagecount; pg++)
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buffer->pages[pg] = &cma_pages[pg];
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buffer->cma_pages = cma_pages;
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buffer->heap = cma_heap;
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buffer->pagecount = pagecount;
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/* create the dmabuf */
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exp_info.exp_name = dma_heap_get_name(heap);
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exp_info.ops = &cma_heap_buf_ops;
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exp_info.size = buffer->len;
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exp_info.flags = fd_flags;
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exp_info.priv = buffer;
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dmabuf = dma_buf_export(&exp_info);
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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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return dmabuf;
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free_pages:
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kfree(buffer->pages);
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free_cma:
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cma_release(cma_heap->cma, cma_pages, pagecount);
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free_buffer:
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kfree(buffer);
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return ERR_PTR(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);
|
||
|
|
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");
|