272 lines
6.1 KiB
C
272 lines
6.1 KiB
C
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// SPDX-License-Identifier: GPL-2.0
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#include <linux/device.h>
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#include <linux/dma-buf.h>
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#include <linux/err.h>
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#include <linux/highmem.h>
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#include <linux/idr.h>
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#include <linux/list.h>
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#include <linux/slab.h>
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#include <linux/uaccess.h>
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#include <linux/vmalloc.h>
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#include <uapi/linux/dma-heap.h>
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#include "heap-helpers.h"
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void init_heap_helper_buffer(struct heap_helper_buffer *buffer,
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void (*free)(struct heap_helper_buffer *))
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{
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buffer->priv_virt = NULL;
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mutex_init(&buffer->lock);
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buffer->vmap_cnt = 0;
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buffer->vaddr = NULL;
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buffer->pagecount = 0;
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buffer->pages = NULL;
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INIT_LIST_HEAD(&buffer->attachments);
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buffer->free = free;
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}
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struct dma_buf *heap_helper_export_dmabuf(struct heap_helper_buffer *buffer,
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int fd_flags)
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{
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DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
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exp_info.ops = &heap_helper_ops;
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exp_info.size = buffer->size;
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exp_info.flags = fd_flags;
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exp_info.priv = buffer;
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return dma_buf_export(&exp_info);
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}
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static void *dma_heap_map_kernel(struct heap_helper_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 void dma_heap_buffer_destroy(struct heap_helper_buffer *buffer)
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{
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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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}
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buffer->free(buffer);
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}
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static void *dma_heap_buffer_vmap_get(struct heap_helper_buffer *buffer)
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{
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void *vaddr;
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if (buffer->vmap_cnt) {
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buffer->vmap_cnt++;
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return buffer->vaddr;
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}
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vaddr = dma_heap_map_kernel(buffer);
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if (IS_ERR(vaddr))
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return vaddr;
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buffer->vaddr = vaddr;
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buffer->vmap_cnt++;
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return vaddr;
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}
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static void dma_heap_buffer_vmap_put(struct heap_helper_buffer *buffer)
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{
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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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}
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struct dma_heaps_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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};
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static int dma_heap_attach(struct dma_buf *dmabuf,
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struct dma_buf_attachment *attachment)
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{
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struct dma_heaps_attachment *a;
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struct heap_helper_buffer *buffer = dmabuf->priv;
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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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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 dma_heap_detach(struct dma_buf *dmabuf,
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struct dma_buf_attachment *attachment)
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{
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struct dma_heaps_attachment *a = attachment->priv;
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struct heap_helper_buffer *buffer = dmabuf->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
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struct sg_table *dma_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_heaps_attachment *a = attachment->priv;
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struct sg_table *table;
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table = &a->table;
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if (!dma_map_sg(attachment->dev, table->sgl, table->nents,
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direction))
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table = ERR_PTR(-ENOMEM);
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return table;
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}
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static void dma_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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dma_unmap_sg(attachment->dev, table->sgl, table->nents, direction);
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}
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static vm_fault_t dma_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 heap_helper_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 = dma_heap_vm_fault,
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};
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static int dma_heap_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma)
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{
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struct heap_helper_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 dma_heap_dma_buf_release(struct dma_buf *dmabuf)
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{
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struct heap_helper_buffer *buffer = dmabuf->priv;
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dma_heap_buffer_destroy(buffer);
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}
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static int dma_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 heap_helper_buffer *buffer = dmabuf->priv;
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struct dma_heaps_attachment *a;
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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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invalidate_kernel_vmap_range(buffer->vaddr, buffer->size);
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list_for_each_entry(a, &buffer->attachments, list) {
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dma_sync_sg_for_cpu(a->dev, a->table.sgl, a->table.nents,
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direction);
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}
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mutex_unlock(&buffer->lock);
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return ret;
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}
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static int dma_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 heap_helper_buffer *buffer = dmabuf->priv;
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struct dma_heaps_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->size);
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list_for_each_entry(a, &buffer->attachments, list) {
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dma_sync_sg_for_device(a->dev, a->table.sgl, a->table.nents,
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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 void *dma_heap_dma_buf_vmap(struct dma_buf *dmabuf)
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{
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struct heap_helper_buffer *buffer = dmabuf->priv;
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void *vaddr;
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mutex_lock(&buffer->lock);
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vaddr = dma_heap_buffer_vmap_get(buffer);
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mutex_unlock(&buffer->lock);
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return vaddr;
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}
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static void dma_heap_dma_buf_vunmap(struct dma_buf *dmabuf, void *vaddr)
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{
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struct heap_helper_buffer *buffer = dmabuf->priv;
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mutex_lock(&buffer->lock);
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dma_heap_buffer_vmap_put(buffer);
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mutex_unlock(&buffer->lock);
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}
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const struct dma_buf_ops heap_helper_ops = {
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.map_dma_buf = dma_heap_map_dma_buf,
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.unmap_dma_buf = dma_heap_unmap_dma_buf,
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.mmap = dma_heap_mmap,
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.release = dma_heap_dma_buf_release,
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.attach = dma_heap_attach,
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.detach = dma_heap_detach,
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.begin_cpu_access = dma_heap_dma_buf_begin_cpu_access,
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.end_cpu_access = dma_heap_dma_buf_end_cpu_access,
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.vmap = dma_heap_dma_buf_vmap,
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.vunmap = dma_heap_dma_buf_vunmap,
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};
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