From ae7871be189cb41184f1e05742b4a99e2c59774d Mon Sep 17 00:00:00 2001 From: Geert Uytterhoeven Date: Fri, 16 Dec 2016 14:28:41 +0100 Subject: swiotlb: Convert swiotlb_force from int to enum Convert the flag swiotlb_force from an int to an enum, to prepare for the advent of more possible values. Suggested-by: Konrad Rzeszutek Wilk Signed-off-by: Geert Uytterhoeven Signed-off-by: Konrad Rzeszutek Wilk --- drivers/xen/swiotlb-xen.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'drivers/xen') diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c index 478fb91..aba1200 100644 --- a/drivers/xen/swiotlb-xen.c +++ b/drivers/xen/swiotlb-xen.c @@ -392,7 +392,7 @@ dma_addr_t xen_swiotlb_map_page(struct device *dev, struct page *page, if (dma_capable(dev, dev_addr, size) && !range_straddles_page_boundary(phys, size) && !xen_arch_need_swiotlb(dev, phys, dev_addr) && - !swiotlb_force) { + (swiotlb_force != SWIOTLB_FORCE)) { /* we are not interested in the dma_addr returned by * xen_dma_map_page, only in the potential cache flushes executed * by the function. */ @@ -552,7 +552,7 @@ xen_swiotlb_map_sg_attrs(struct device *hwdev, struct scatterlist *sgl, phys_addr_t paddr = sg_phys(sg); dma_addr_t dev_addr = xen_phys_to_bus(paddr); - if (swiotlb_force || + if (swiotlb_force == SWIOTLB_FORCE || xen_arch_need_swiotlb(hwdev, paddr, dev_addr) || !dma_capable(hwdev, dev_addr, sg->length) || range_straddles_page_boundary(paddr, sg->length)) { -- cgit v1.1 From 7453c549f5f6485c0d79cad7844870dcc7d1b34d Mon Sep 17 00:00:00 2001 From: Konrad Rzeszutek Wilk Date: Tue, 20 Dec 2016 10:02:02 -0500 Subject: swiotlb: Export swiotlb_max_segment to users So they can figure out what is the optimal number of pages that can be contingously stitched together without fear of bounce buffer. We also expose an mechanism for sub-users of SWIOTLB API, such as Xen-SWIOTLB to set the max segment value. And lastly if swiotlb=force is set (which mandates we bounce buffer everything) we set max_segment so at least we can bounce buffer one 4K page instead of a giant 512KB one for which we may not have space. Signed-off-by: Konrad Rzeszutek Wilk Reported-and-Tested-by: Juergen Gross --- drivers/xen/swiotlb-xen.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'drivers/xen') diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c index aba1200..f905d6e 100644 --- a/drivers/xen/swiotlb-xen.c +++ b/drivers/xen/swiotlb-xen.c @@ -275,6 +275,10 @@ retry: rc = 0; } else rc = swiotlb_late_init_with_tbl(xen_io_tlb_start, xen_io_tlb_nslabs); + + if (!rc) + swiotlb_set_max_segment(PAGE_SIZE); + return rc; error: if (repeat--) { -- cgit v1.1