swiotlb-xen: remove start_dma_addr

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.

Note that virt_to_phys is not the same as xen_virt_to_bus but actually
it is used to compared again __pa(xen_io_tlb_start) as passed to
swiotlb_init_with_tbl, so virt_to_phys is actually what we want.

Signed-off-by: Stefano Stabellini <stefano.stabellini@xilinx.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Tested-by: Corey Minyard <cminyard@mvista.com>
Tested-by: Roman Shaposhnik <roman@zededa.com>
Link: https://lore.kernel.org/r/20200710223427.6897-2-sstabellini@kernel.org
Signed-off-by: Juergen Gross <jgross@suse.com>
This commit is contained in:
Stefano Stabellini 2020-07-10 15:34:18 -07:00 committed by Juergen Gross
parent 8b1e868f66
commit ae4f0a17ee

View File

@ -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 @@ retry:
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))
@ -392,8 +389,8 @@ 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,
size, size, dir, attrs);
map = swiotlb_tbl_map_single(dev, virt_to_phys(xen_io_tlb_start),
phys, size, size, dir, attrs);
if (map == (phys_addr_t)DMA_MAPPING_ERROR)
return DMA_MAPPING_ERROR;