参照元†
- phys_addr_t phys_addr
- dma_addr_t device_addr
- size_t size
- int flags
- struct dma_coherent_mem **mem
返り値†
static int dma_init_coherent_memory(phys_addr_t phys_addr, dma_addr_t device_addr,
size_t size, int flags,
struct dma_coherent_mem **mem)
{
struct dma_coherent_mem *dma_mem = NULL;
void __iomem *mem_base = NULL;
int pages = size >> PAGE_SHIFT;
int bitmap_size = BITS_TO_LONGS(pages) * sizeof(long);
if ((flags & (DMA_MEMORY_MAP | DMA_MEMORY_IO)) == 0)
goto out;
if (!size)
goto out;
mem_base = ioremap(phys_addr, size);
if (!mem_base)
goto out;
dma_mem = kzalloc(sizeof(struct dma_coherent_mem), GFP_KERNEL);
if (!dma_mem)
goto out;
dma_mem->bitmap = kzalloc(bitmap_size, GFP_KERNEL);
if (!dma_mem->bitmap)
goto out;
dma_mem->virt_base = mem_base;
dma_mem->device_base = device_addr;
dma_mem->pfn_base = PFN_DOWN(phys_addr);
dma_mem->size = pages;
dma_mem->flags = flags;
spin_lock_init(&dma_mem->spinlock);
*mem = dma_mem;
if (flags & DMA_MEMORY_MAP)
return DMA_MEMORY_MAP;
return DMA_MEMORY_IO;
out:
kfree(dma_mem);
if (mem_base)
iounmap(mem_base);
return 0;
}
コメント†