diff options
Diffstat (limited to 'drivers/xen/swiotlb-xen.c')
| -rw-r--r-- | drivers/xen/swiotlb-xen.c | 23 |
1 files changed, 12 insertions, 11 deletions
diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c index 5dcb06fe9667..d53f3493a6b9 100644 --- a/drivers/xen/swiotlb-xen.c +++ b/drivers/xen/swiotlb-xen.c @@ -1,18 +1,10 @@ +// SPDX-License-Identifier: GPL-2.0-only /* * Copyright 2010 * by Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> * * This code provides a IOMMU for Xen PV guests with PCI passthrough. * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License v2.0 as published by - * the Free Software Foundation - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * * PV guests under Xen are running in an non-contiguous memory architecture. * * When PCI pass-through is utilized, this necessitates an IOMMU for @@ -30,7 +22,6 @@ * and PFN+1==MFN+1. Lastly with Xen 4.0, pages (in debug mode) are * allocated in descending order (high to low), meaning the guest might * never get any MFN's under the 4GB mark. - * */ #define pr_fmt(fmt) "xen:" KBUILD_MODNAME ": " fmt @@ -211,6 +202,15 @@ int __ref xen_swiotlb_init(int verbose, bool early) retry: bytes = xen_set_nslabs(xen_io_tlb_nslabs); order = get_order(xen_io_tlb_nslabs << IO_TLB_SHIFT); + + /* + * IO TLB memory already allocated. Just use it. + */ + if (io_tlb_start != 0) { + xen_io_tlb_start = phys_to_virt(io_tlb_start); + goto end; + } + /* * Get IO TLB memory from any location. */ @@ -240,7 +240,6 @@ retry: m_ret = XEN_SWIOTLB_ENOMEM; goto error; } - xen_io_tlb_end = xen_io_tlb_start + bytes; /* * And replace that memory with pages under 4GB. */ @@ -267,6 +266,8 @@ retry: } else rc = swiotlb_late_init_with_tbl(xen_io_tlb_start, xen_io_tlb_nslabs); +end: + xen_io_tlb_end = xen_io_tlb_start + bytes; if (!rc) swiotlb_set_max_segment(PAGE_SIZE); |