Messages in this thread | | | Subject | Re: [PATCH 02/10] swiotlb-xen: remove start_dma_addr | From | Julien Grall <> | Date | Thu, 21 May 2020 09:05:07 +0100 |
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Hi,
On 21/05/2020 00:45, Stefano Stabellini wrote: > From: Stefano Stabellini <stefano.stabellini@xilinx.com> > > It is not strictly needed. Call virt_to_phys on xen_io_tlb_start > instead. It will be useful not to have a start_dma_addr around with the > next patches. > > Signed-off-by: Stefano Stabellini <stefano.stabellini@xilinx.com> > --- > drivers/xen/swiotlb-xen.c | 5 +---- > 1 file changed, 1 insertion(+), 4 deletions(-) > > diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c > index a42129cba36e..b5e0492b07b9 100644 > --- a/drivers/xen/swiotlb-xen.c > +++ b/drivers/xen/swiotlb-xen.c > @@ -52,8 +52,6 @@ static unsigned long xen_io_tlb_nslabs; > * Quick lookup value of the bus address of the IOTLB. > */ > > -static u64 start_dma_addr; > - > /* > * Both of these functions should avoid XEN_PFN_PHYS because phys_addr_t > * can be 32bit when dma_addr_t is 64bit leading to a loss in > @@ -241,7 +239,6 @@ int __ref xen_swiotlb_init(int verbose, bool early) > m_ret = XEN_SWIOTLB_EFIXUP; > goto error; > } > - start_dma_addr = xen_virt_to_bus(xen_io_tlb_start); > if (early) { > if (swiotlb_init_with_tbl(xen_io_tlb_start, xen_io_tlb_nslabs, > verbose)) > @@ -389,7 +386,7 @@ static dma_addr_t xen_swiotlb_map_page(struct device *dev, struct page *page, > */ > trace_swiotlb_bounced(dev, dev_addr, size, swiotlb_force); > > - map = swiotlb_tbl_map_single(dev, start_dma_addr, phys, > + map = swiotlb_tbl_map_single(dev, virt_to_phys(xen_io_tlb_start), phys,
xen_virt_to_bus() is implemented as xen_phys_to_bus(virt_to_phys()). Can you explain how the two are equivalent?
Cheers,
-- Julien Grall
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