参照元†
- FIXME: これは何？
- 説明
- dma_alloc_coherent() がメモリを確保する
- struct ion_heap *heap
- struct ion_buffer *buffer
- unsigned long len
- unsigned long align
- unsigned long flags
- 割り当てる領域の属性フラグ
- ION_FLAG_XXX を OR で指定
返り値†
- int
- 成功なら 0、失敗なら ION_CMA_ALLOCATE_FAILED
/* ION CMA heap operations functions */
static int ion_cma_allocate(struct ion_heap *heap, struct ion_buffer *buffer,
unsigned long len, unsigned long align,
unsigned long flags)
{
struct ion_cma_heap *cma_heap = to_cma_heap(heap);
struct device *dev = cma_heap->dev;
struct ion_cma_buffer_info *info;
dev_dbg(dev, "Request buffer allocation len %ld\n", len);
if (buffer->flags & ION_FLAG_CACHED)
return -EINVAL;
if (align > PAGE_SIZE)
return -EINVAL;
info = kzalloc(sizeof(struct ion_cma_buffer_info), GFP_KERNEL);
if (!info)
return ION_CMA_ALLOCATE_FAILED;
info->cpu_addr = dma_alloc_coherent(dev, len, &(info->handle),
GFP_HIGHUSER | __GFP_ZERO);
if (!info->cpu_addr) {
dev_err(dev, "Fail to allocate buffer\n");
goto err;
}
info->table = kmalloc(sizeof(struct sg_table), GFP_KERNEL);
if (!info->table)
goto free_mem;
if (dma_get_sgtable(dev, info->table, info->cpu_addr, info->handle,
len))
goto free_table;
/* keep this for memory release */
buffer->priv_virt = info;
dev_dbg(dev, "Allocate buffer %p\n", buffer);
return 0;
free_table:
kfree(info->table);
free_mem:
dma_free_coherent(dev, len, info->cpu_addr, info->handle);
err:
kfree(info);
return ION_CMA_ALLOCATE_FAILED;
}
コメント†
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