* [PATCH resend] swiotlb: ensure that page-sized mappings are page-aligned
@ 2017-01-11 18:56 Nikita Yushchenko
2017-01-12 7:55 ` Christoph Hellwig
` (2 more replies)
0 siblings, 3 replies; 4+ messages in thread
From: Nikita Yushchenko @ 2017-01-11 18:56 UTC (permalink / raw)
To: Konrad Rzeszutek Wilk
Cc: linux-kernel, Artemi Ivanov, Christoph Hellwig, linux-nvme,
Nikita Yushchenko
Some drivers do depend on page mappings to be page aligned.
Swiotlb already enforces such alignment for mappings greater than page,
extend that to page-sized mappings as well.
Without this fix, nvme hits BUG() in nvme_setup_prps(), because that routine
assumes page-aligned mappings.
Signed-off-by: Nikita Yushchenko <nikita.yoush@cogentembedded.com>
---
lib/swiotlb.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/lib/swiotlb.c b/lib/swiotlb.c
index 975b8fc..a8d74a7 100644
--- a/lib/swiotlb.c
+++ b/lib/swiotlb.c
@@ -483,11 +483,11 @@ phys_addr_t swiotlb_tbl_map_single(struct device *hwdev,
: 1UL << (BITS_PER_LONG - IO_TLB_SHIFT);
/*
- * For mappings greater than a page, we limit the stride (and
- * hence alignment) to a page size.
+ * For mappings greater than or equal to a page, we limit the stride
+ * (and hence alignment) to a page size.
*/
nslots = ALIGN(size, 1 << IO_TLB_SHIFT) >> IO_TLB_SHIFT;
- if (size > PAGE_SIZE)
+ if (size >= PAGE_SIZE)
stride = (1 << (PAGE_SHIFT - IO_TLB_SHIFT));
else
stride = 1;
--
2.1.4
^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: [PATCH resend] swiotlb: ensure that page-sized mappings are page-aligned
2017-01-11 18:56 [PATCH resend] swiotlb: ensure that page-sized mappings are page-aligned Nikita Yushchenko
@ 2017-01-12 7:55 ` Christoph Hellwig
2017-01-12 9:09 ` Sagi Grimberg
2017-01-15 17:41 ` Konrad Rzeszutek Wilk
2 siblings, 0 replies; 4+ messages in thread
From: Christoph Hellwig @ 2017-01-12 7:55 UTC (permalink / raw)
To: Nikita Yushchenko
Cc: Konrad Rzeszutek Wilk, linux-kernel, Artemi Ivanov,
Christoph Hellwig, linux-nvme
Looks good,
Reviewed-by: Christoph Hellwig <hch@lst.de>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH resend] swiotlb: ensure that page-sized mappings are page-aligned
2017-01-11 18:56 [PATCH resend] swiotlb: ensure that page-sized mappings are page-aligned Nikita Yushchenko
2017-01-12 7:55 ` Christoph Hellwig
@ 2017-01-12 9:09 ` Sagi Grimberg
2017-01-15 17:41 ` Konrad Rzeszutek Wilk
2 siblings, 0 replies; 4+ messages in thread
From: Sagi Grimberg @ 2017-01-12 9:09 UTC (permalink / raw)
To: Nikita Yushchenko, Konrad Rzeszutek Wilk
Cc: Artemi Ivanov, linux-kernel, linux-nvme, Christoph Hellwig
Looks good,
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH resend] swiotlb: ensure that page-sized mappings are page-aligned
2017-01-11 18:56 [PATCH resend] swiotlb: ensure that page-sized mappings are page-aligned Nikita Yushchenko
2017-01-12 7:55 ` Christoph Hellwig
2017-01-12 9:09 ` Sagi Grimberg
@ 2017-01-15 17:41 ` Konrad Rzeszutek Wilk
2 siblings, 0 replies; 4+ messages in thread
From: Konrad Rzeszutek Wilk @ 2017-01-15 17:41 UTC (permalink / raw)
To: Nikita Yushchenko
Cc: Konrad Rzeszutek Wilk, linux-kernel, Artemi Ivanov,
Christoph Hellwig, linux-nvme
On Wed, Jan 11, 2017 at 09:56:31PM +0300, Nikita Yushchenko wrote:
> Some drivers do depend on page mappings to be page aligned.
>
> Swiotlb already enforces such alignment for mappings greater than page,
> extend that to page-sized mappings as well.
>
> Without this fix, nvme hits BUG() in nvme_setup_prps(), because that routine
> assumes page-aligned mappings.
>
> Signed-off-by: Nikita Yushchenko <nikita.yoush@cogentembedded.com>
I queued it up in stable/for-linus-4.10 in swiotlb queue tree.
> ---
> lib/swiotlb.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/lib/swiotlb.c b/lib/swiotlb.c
> index 975b8fc..a8d74a7 100644
> --- a/lib/swiotlb.c
> +++ b/lib/swiotlb.c
> @@ -483,11 +483,11 @@ phys_addr_t swiotlb_tbl_map_single(struct device *hwdev,
> : 1UL << (BITS_PER_LONG - IO_TLB_SHIFT);
>
> /*
> - * For mappings greater than a page, we limit the stride (and
> - * hence alignment) to a page size.
> + * For mappings greater than or equal to a page, we limit the stride
> + * (and hence alignment) to a page size.
> */
> nslots = ALIGN(size, 1 << IO_TLB_SHIFT) >> IO_TLB_SHIFT;
> - if (size > PAGE_SIZE)
> + if (size >= PAGE_SIZE)
> stride = (1 << (PAGE_SHIFT - IO_TLB_SHIFT));
> else
> stride = 1;
> --
> 2.1.4
>
^ permalink raw reply [flat|nested] 4+ messages in thread
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2017-01-11 18:56 [PATCH resend] swiotlb: ensure that page-sized mappings are page-aligned Nikita Yushchenko
2017-01-12 7:55 ` Christoph Hellwig
2017-01-12 9:09 ` Sagi Grimberg
2017-01-15 17:41 ` Konrad Rzeszutek Wilk
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