- again:
- page = dma_alloc_pages(dev,
- noretry ? gfp | __GFP_NORETRY : gfp, get_order(size));
- if (page == NULL)
- return NULL;
-
- {
- int high, mmu;
- bus = page_to_phys(page);
- memory = page_address(page);
- high = (bus + size) >= dma_mask;
- mmu = high;
- if (force_iommu && !(gfp & GFP_DMA))
- mmu = 1;
- else if (high) {
- free_pages((unsigned long)memory,
- get_order(size));
-
- /* Don't use the 16MB ZONE_DMA unless absolutely
- needed. It's better to use remapping first. */
- if (dma_mask < DMA_32BIT_MASK && !(gfp & GFP_DMA)) {
- gfp = (gfp & ~GFP_DMA32) | GFP_DMA;
- goto again;
- }
-
- /* Let low level make its own zone decisions */
- gfp &= ~(GFP_DMA32|GFP_DMA);
-
- if (ops->alloc_coherent)
- return ops->alloc_coherent(dev, size,
- dma_handle, gfp);
- return NULL;
- }
-
- memset(memory, 0, size);
- if (!mmu) {
- *dma_handle = bus;
- return memory;
- }
- }
-
- if (ops->alloc_coherent) {
- free_pages((unsigned long)memory, get_order(size));
- gfp &= ~(GFP_DMA|GFP_DMA32);
- return ops->alloc_coherent(dev, size, dma_handle, gfp);
- }
-
- if (ops->map_simple) {
- *dma_handle = ops->map_simple(dev, virt_to_phys(memory),
- size,
- PCI_DMA_BIDIRECTIONAL);
- if (*dma_handle != bad_dma_address)
- return memory;
- }
-
- if (panic_on_overflow)
- panic("dma_alloc_coherent: IOMMU overflow by %lu bytes\n",
- (unsigned long)size);
- free_pages((unsigned long)memory, get_order(size));