From 5d0538b2b884f7fd239f6ab3b667148dc57123f1 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Mon, 1 Mar 2021 08:44:31 +0100 Subject: [PATCH] swiotlb: lift the double initialization protection from xen-swiotlb Lift the double initialization protection from xen-swiotlb to the core code to avoid exposing too many swiotlb internals. Also upgrade the check to a warning as it should not happen. Signed-off-by: Christoph Hellwig Signed-off-by: Konrad Rzeszutek Wilk --- drivers/xen/swiotlb-xen.c | 7 ------- kernel/dma/swiotlb.c | 8 ++++++++ 2 files changed, 8 insertions(+), 7 deletions(-) diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c index 1a31ddf713979..060eeb056486f 100644 --- a/drivers/xen/swiotlb-xen.c +++ b/drivers/xen/swiotlb-xen.c @@ -172,12 +172,6 @@ int __ref xen_swiotlb_init(int verbose, bool early) bytes = nslabs << IO_TLB_SHIFT; order = get_order(bytes); - /* - * IO TLB memory already allocated. Just use it. - */ - if (io_tlb_start != 0) - goto end; - /* * Get IO TLB memory from any location. */ @@ -232,7 +226,6 @@ int __ref xen_swiotlb_init(int verbose, bool early) } else rc = swiotlb_late_init_with_tbl(start, nslabs); -end: if (!rc) swiotlb_set_max_segment(PAGE_SIZE); diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c index 5fe8781be6f26..35e24f0ff8b20 100644 --- a/kernel/dma/swiotlb.c +++ b/kernel/dma/swiotlb.c @@ -229,6 +229,10 @@ int __init swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose) unsigned long i, bytes; size_t alloc_size; + /* protect against double initialization */ + if (WARN_ON_ONCE(io_tlb_start)) + return -ENOMEM; + bytes = nslabs << IO_TLB_SHIFT; io_tlb_nslabs = nslabs; @@ -367,6 +371,10 @@ swiotlb_late_init_with_tbl(char *tlb, unsigned long nslabs) { unsigned long i, bytes; + /* protect against double initialization */ + if (WARN_ON_ONCE(io_tlb_start)) + return -ENOMEM; + bytes = nslabs << IO_TLB_SHIFT; io_tlb_nslabs = nslabs;