s390/pci_dma: improve map_sg (ee877b81) · Commits · 戴 / test

arch/s390/pci/pci_dma.c

+82 −24

Original line number	Diff line number	Diff line
		@@ -388,37 +388,94 @@ static void s390_dma_free(struct device *dev, size_t size,
		free_pages((unsigned long) pa, get_order(size));
		}

		static int s390_dma_map_sg(struct device dev, struct scatterlist sg,
		int nr_elements, enum dma_data_direction dir,
		unsigned long attrs)
		/* Map a segment into a contiguous dma address area */
		static int __s390_dma_map_sg(struct device dev, struct scatterlist sg,
		size_t size, dma_addr_t *handle,
		enum dma_data_direction dir)
		{
		int mapped_elements = 0;
		struct zpci_dev *zdev = to_zpci(to_pci_dev(dev));
		dma_addr_t dma_addr_base, dma_addr;
		int flags = ZPCI_PTE_VALID;
		struct scatterlist *s;
		int i;
		unsigned long pa;
		int ret;

		for_each_sg(sg, s, nr_elements, i) {
		struct page *page = sg_page(s);
		s->dma_address = s390_dma_map_pages(dev, page, s->offset,
		s->length, dir, 0);
		if (!dma_mapping_error(dev, s->dma_address)) {
		s->dma_length = s->length;
		mapped_elements++;
		} else
		size = PAGE_ALIGN(size);
		dma_addr_base = dma_alloc_address(dev, size >> PAGE_SHIFT);
		if (dma_addr_base == DMA_ERROR_CODE)
		return -ENOMEM;

		dma_addr = dma_addr_base;
		if (dir == DMA_NONE \|\| dir == DMA_TO_DEVICE)
		flags \|= ZPCI_TABLE_PROTECTED;

		for (s = sg; dma_addr < dma_addr_base + size; s = sg_next(s)) {
		pa = page_to_phys(sg_page(s)) + s->offset;
		ret = dma_update_trans(zdev, pa, dma_addr, s->length, flags);
		if (ret)
		goto unmap;

		dma_addr += s->length;
		}
		out:
		return mapped_elements;
		*handle = dma_addr_base;
		atomic64_add(size >> PAGE_SHIFT, &zdev->mapped_pages);

		return ret;

		unmap:
		for_each_sg(sg, s, mapped_elements, i) {
		if (s->dma_address)
		s390_dma_unmap_pages(dev, s->dma_address, s->dma_length,
		dir, 0);
		s->dma_address = 0;
		dma_update_trans(zdev, 0, dma_addr_base, dma_addr - dma_addr_base,
		ZPCI_PTE_INVALID);
		dma_free_address(dev, dma_addr_base, size >> PAGE_SHIFT);
		zpci_err("map error:\n");
		zpci_err_dma(ret, pa);
		return ret;
		}

		static int s390_dma_map_sg(struct device dev, struct scatterlist sg,
		int nr_elements, enum dma_data_direction dir,
		unsigned long attrs)
		{
		struct scatterlist s = sg, start = sg, *dma = sg;
		unsigned int max = dma_get_max_seg_size(dev);
		unsigned int size = s->offset + s->length;
		unsigned int offset = s->offset;
		int count = 0, i;

		for (i = 1; i < nr_elements; i++) {
		s = sg_next(s);

		s->dma_address = DMA_ERROR_CODE;
		s->dma_length = 0;

		if (s->offset \|\| (size & ~PAGE_MASK) \|\|
		size + s->length > max) {
		if (__s390_dma_map_sg(dev, start, size,
		&dma->dma_address, dir))
		goto unmap;

		dma->dma_address += offset;
		dma->dma_length = size - offset;

		size = offset = s->offset;
		start = s;
		dma = sg_next(dma);
		count++;
		}
		mapped_elements = 0;
		goto out;
		size += s->length;
		}
		if (__s390_dma_map_sg(dev, start, size, &dma->dma_address, dir))
		goto unmap;

		dma->dma_address += offset;
		dma->dma_length = size - offset;

		return count + 1;
		unmap:
		for_each_sg(sg, s, count, i)
		s390_dma_unmap_pages(dev, sg_dma_address(s), sg_dma_len(s),
		dir, attrs);

		return 0;
		}

		static void s390_dma_unmap_sg(struct device dev, struct scatterlist sg,
		@@ -429,8 +486,9 @@ static void s390_dma_unmap_sg(struct device dev, struct scatterlist sg,
		int i;

		for_each_sg(sg, s, nr_elements, i) {
		s390_dma_unmap_pages(dev, s->dma_address, s->dma_length, dir,
		0);
		if (s->dma_length)
		s390_dma_unmap_pages(dev, s->dma_address, s->dma_length,
		dir, attrs);
		s->dma_address = 0;
		s->dma_length = 0;
		}

Admin message