From: Christoph Hellwig <hch@lst.de>
To: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>,
Dongli Zhang <dongli.zhang@oracle.com>,
Claire Chang <tientzu@chromium.org>,
xen-devel@lists.xenproject.org, linuxppc-dev@lists.ozlabs.org,
iommu@lists.linux-foundation.org
Subject: [PATCH 6/8] swiotlb: lift the double initialization protection from xen-swiotlb
Date: Sun, 7 Feb 2021 17:09:32 +0100 [thread overview]
Message-ID: <20210207160934.2955931-7-hch@lst.de> (raw)
In-Reply-To: <20210207160934.2955931-1-hch@lst.de>
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 <hch@lst.de>
---
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 6e0f2c5ecd1a2f..e6c8556e879ee6 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 adcc3c87e10078..a3737961ae5769 100644
--- a/kernel/dma/swiotlb.c
+++ b/kernel/dma/swiotlb.c
@@ -224,6 +224,10 @@ 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;
@@ -355,6 +359,10 @@ 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;
--
2.29.2
next prev parent reply other threads:[~2021-02-07 16:10 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-07 16:09 swiotlb cleanups Christoph Hellwig
2021-02-07 16:09 ` [PATCH 1/8] powerpc/svm: stop using io_tlb_start Christoph Hellwig
2021-02-07 16:09 ` [PATCH 2/8] xen-swiotlb: use is_swiotlb_buffer in is_xen_swiotlb_buffer Christoph Hellwig
2021-02-19 20:43 ` Konrad Rzeszutek Wilk
2021-02-07 16:09 ` [PATCH 3/8] xen-swiotlb: use io_tlb_end in xen_swiotlb_dma_supported Christoph Hellwig
2021-02-19 21:00 ` Konrad Rzeszutek Wilk
2021-02-07 16:09 ` [PATCH 4/8] xen-swiotlb: remove xen_set_nslabs Christoph Hellwig
2021-02-07 16:09 ` [PATCH 5/8] xen-swiotlb: remove xen_io_tlb_start and xen_io_tlb_nslabs Christoph Hellwig
2021-02-07 16:09 ` Christoph Hellwig [this message]
2021-02-07 16:09 ` [PATCH 7/8] xen-swiotlb: split xen_swiotlb_init Christoph Hellwig
2021-02-07 16:09 ` [PATCH 8/8] xen-swiotlb: remove the unused size argument from xen_swiotlb_fixup Christoph Hellwig
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