* [PATCH] dmaengine: async_xor, fix zero address issue when xor highmem page
@ 2011-12-27 6:30 b29237
2012-01-11 7:51 ` Shi Xuelin-B29237
0 siblings, 1 reply; 3+ messages in thread
From: b29237 @ 2011-12-27 6:30 UTC (permalink / raw)
To: vinod.koul, dan.j.williams, linuxppc-dev, linux-kernel, r58472
Cc: Forrest shi
From: Forrest shi <b29237@freescale.com>
we may do_sync_xor high mem pages, in this case, page_address will
return zero address which cause a failure.
this patch uses kmap_atomic before xor the pages and kunmap_atomic
after it.
Signed-off-by: b29237@freescale.com <xuelin.shi@freescale.com>
---
crypto/async_tx/async_xor.c | 16 ++++++++++++----
1 files changed, 12 insertions(+), 4 deletions(-)
diff --git a/crypto/async_tx/async_xor.c b/crypto/async_tx/async_xor.c
index bc28337..5b416d1 100644
--- a/crypto/async_tx/async_xor.c
+++ b/crypto/async_tx/async_xor.c
@@ -26,6 +26,7 @@
#include <linux/kernel.h>
#include <linux/interrupt.h>
#include <linux/mm.h>
+#include <linux/highmem.h>
#include <linux/dma-mapping.h>
#include <linux/raid/xor.h>
#include <linux/async_tx.h>
@@ -126,7 +127,7 @@ do_sync_xor(struct page *dest, struct page **src_list, unsigned int offset,
int src_cnt, size_t len, struct async_submit_ctl *submit)
{
int i;
- int xor_src_cnt = 0;
+ int xor_src_cnt = 0, kmap_cnt=0;
int src_off = 0;
void *dest_buf;
void **srcs;
@@ -138,11 +139,13 @@ do_sync_xor(struct page *dest, struct page **src_list, unsigned int offset,
/* convert to buffer pointers */
for (i = 0; i < src_cnt; i++)
- if (src_list[i])
- srcs[xor_src_cnt++] = page_address(src_list[i]) + offset;
+ if (src_list[i]) {
+ srcs[xor_src_cnt++] = kmap_atomic(src_list[i], KM_USER1) + offset;
+ }
+ kmap_cnt = xor_src_cnt;
src_cnt = xor_src_cnt;
/* set destination address */
- dest_buf = page_address(dest) + offset;
+ dest_buf = kmap_atomic(dest, KM_USER0) + offset;
if (submit->flags & ASYNC_TX_XOR_ZERO_DST)
memset(dest_buf, 0, len);
@@ -157,6 +160,11 @@ do_sync_xor(struct page *dest, struct page **src_list, unsigned int offset,
src_off += xor_src_cnt;
}
+ kunmap_atomic(dest_buf, KM_USER0);
+ for (i = 0; i < kmap_cnt; i++)
+ if (src_list[i])
+ kunmap_atomic(srcs[i], KM_USER1);
+
async_tx_sync_epilog(submit);
}
--
1.7.0.4
^ permalink raw reply related [flat|nested] 3+ messages in thread* RE: [PATCH] dmaengine: async_xor, fix zero address issue when xor highmem page
2011-12-27 6:30 [PATCH] dmaengine: async_xor, fix zero address issue when xor highmem page b29237
@ 2012-01-11 7:51 ` Shi Xuelin-B29237
2012-01-26 9:12 ` Dan Williams
0 siblings, 1 reply; 3+ messages in thread
From: Shi Xuelin-B29237 @ 2012-01-11 7:51 UTC (permalink / raw)
To: dan.j.williams@intel.com
Cc: vinod.koul@intel.com, linuxppc-dev@lists.ozlabs.org,
linux-kernel@vger.kernel.org, Li Yang-R58472
Hello Dan Williams,
Do you have any comment about this patch?
Thanks,
Forrest
-----Original Message-----
From: Shi Xuelin-B29237=20
Sent: 2011=1B$BG/=1B(B12=1B$B7n=1B(B27=1B$BF|=1B(B 14:31
To: vinod.koul@intel.com; dan.j.williams@intel.com; linuxppc-dev@lists.ozla=
bs.org; linux-kernel@vger.kernel.org; Li Yang-R58472
Cc: Shi Xuelin-B29237
Subject: [PATCH] dmaengine: async_xor, fix zero address issue when xor high=
mem page
From: Forrest shi <b29237@freescale.com>
we may do_sync_xor high mem pages, in this case, page_address will
return zero address which cause a failure.
this patch uses kmap_atomic before xor the pages and kunmap_atomic
after it.
Signed-off-by: b29237@freescale.com <xuelin.shi@freescale.com>
---
crypto/async_tx/async_xor.c | 16 ++++++++++++----
1 files changed, 12 insertions(+), 4 deletions(-)
diff --git a/crypto/async_tx/async_xor.c b/crypto/async_tx/async_xor.c inde=
x bc28337..5b416d1 100644
--- a/crypto/async_tx/async_xor.c
+++ b/crypto/async_tx/async_xor.c
@@ -26,6 +26,7 @@
#include <linux/kernel.h>
#include <linux/interrupt.h>
#include <linux/mm.h>
+#include <linux/highmem.h>
#include <linux/dma-mapping.h>
#include <linux/raid/xor.h>
#include <linux/async_tx.h>
@@ -126,7 +127,7 @@ do_sync_xor(struct page *dest, struct page **src_list, =
unsigned int offset,
int src_cnt, size_t len, struct async_submit_ctl *submit) {
int i;
- int xor_src_cnt =3D 0;
+ int xor_src_cnt =3D 0, kmap_cnt=3D0;
int src_off =3D 0;
void *dest_buf;
void **srcs;
@@ -138,11 +139,13 @@ do_sync_xor(struct page *dest, struct page **src_list=
, unsigned int offset,
=20
/* convert to buffer pointers */
for (i =3D 0; i < src_cnt; i++)
- if (src_list[i])
- srcs[xor_src_cnt++] =3D page_address(src_list[i]) + offset;
+ if (src_list[i]) {
+ srcs[xor_src_cnt++] =3D kmap_atomic(src_list[i], KM_USER1) + offset;
+ }
+ kmap_cnt =3D xor_src_cnt;
src_cnt =3D xor_src_cnt;
/* set destination address */
- dest_buf =3D page_address(dest) + offset;
+ dest_buf =3D kmap_atomic(dest, KM_USER0) + offset;
=20
if (submit->flags & ASYNC_TX_XOR_ZERO_DST)
memset(dest_buf, 0, len);
@@ -157,6 +160,11 @@ do_sync_xor(struct page *dest, struct page **src_list,=
unsigned int offset,
src_off +=3D xor_src_cnt;
}
=20
+ kunmap_atomic(dest_buf, KM_USER0);
+ for (i =3D 0; i < kmap_cnt; i++)=20
+ if (src_list[i])
+ kunmap_atomic(srcs[i], KM_USER1);
+
async_tx_sync_epilog(submit);
}
=20
--
1.7.0.4
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [PATCH] dmaengine: async_xor, fix zero address issue when xor highmem page
2012-01-11 7:51 ` Shi Xuelin-B29237
@ 2012-01-26 9:12 ` Dan Williams
0 siblings, 0 replies; 3+ messages in thread
From: Dan Williams @ 2012-01-26 9:12 UTC (permalink / raw)
To: Shi Xuelin-B29237
Cc: vinod.koul@intel.com, linuxppc-dev@lists.ozlabs.org,
linux-kernel@vger.kernel.org, Li Yang-R58472
2012/1/10 Shi Xuelin-B29237 <B29237@freescale.com>:
> Hello Dan Williams,
>
> Do you have any comment about this patch?
Hi, sorrry for the delay.
>
> Thanks,
> Forrest
>
> -----Original Message-----
> From: Shi Xuelin-B29237
> Sent: 2011=E5=B9=B412=E6=9C=8827=E6=97=A5 14:31
> To: vinod.koul@intel.com; dan.j.williams@intel.com; linuxppc-dev@lists.oz=
labs.org; linux-kernel@vger.kernel.org; Li Yang-R58472
> Cc: Shi Xuelin-B29237
> Subject: [PATCH] dmaengine: async_xor, fix zero address issue when xor hi=
ghmem page
>
> From: Forrest shi <b29237@freescale.com>
>
> =C2=A0 =C2=A0 =C2=A0 =C2=A0we may do_sync_xor high mem pages, in this cas=
e, page_address will
> =C2=A0 =C2=A0 =C2=A0 =C2=A0return zero address which cause a failure.
In what scenarios do we xor highmem?
In the case of raid we currently always xor on kmalloc'd memory.
>
> =C2=A0 =C2=A0 =C2=A0 =C2=A0this patch uses kmap_atomic before xor the pag=
es and kunmap_atomic
> =C2=A0 =C2=A0 =C2=A0 =C2=A0after it.
>
> =C2=A0 =C2=A0 =C2=A0 =C2=A0Signed-off-by: b29237@freescale.com <xuelin.sh=
i@freescale.com>
> ---
> =C2=A0crypto/async_tx/async_xor.c | =C2=A0 16 ++++++++++++----
> =C2=A01 files changed, 12 insertions(+), 4 deletions(-)
>
> diff --git a/crypto/async_tx/async_xor.c b/crypto/async_tx/async_xor.c in=
dex bc28337..5b416d1 100644
> --- a/crypto/async_tx/async_xor.c
> +++ b/crypto/async_tx/async_xor.c
> @@ -26,6 +26,7 @@
> =C2=A0#include <linux/kernel.h>
> =C2=A0#include <linux/interrupt.h>
> =C2=A0#include <linux/mm.h>
> +#include <linux/highmem.h>
> =C2=A0#include <linux/dma-mapping.h>
> =C2=A0#include <linux/raid/xor.h>
> =C2=A0#include <linux/async_tx.h>
> @@ -126,7 +127,7 @@ do_sync_xor(struct page *dest, struct page **src_list=
, unsigned int offset,
> =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0int src_cnt, size_t len, struct =
async_submit_ctl *submit) =C2=A0{
> =C2=A0 =C2=A0 =C2=A0 =C2=A0int i;
> - =C2=A0 =C2=A0 =C2=A0 int xor_src_cnt =3D 0;
> + =C2=A0 =C2=A0 =C2=A0 int xor_src_cnt =3D 0, kmap_cnt=3D0;
> =C2=A0 =C2=A0 =C2=A0 =C2=A0int src_off =3D 0;
> =C2=A0 =C2=A0 =C2=A0 =C2=A0void *dest_buf;
> =C2=A0 =C2=A0 =C2=A0 =C2=A0void **srcs;
> @@ -138,11 +139,13 @@ do_sync_xor(struct page *dest, struct page **src_li=
st, unsigned int offset,
>
> =C2=A0 =C2=A0 =C2=A0 =C2=A0/* convert to buffer pointers */
> =C2=A0 =C2=A0 =C2=A0 =C2=A0for (i =3D 0; i < src_cnt; i++)
> - =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 if (src_list[i])
> - =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =
=C2=A0 srcs[xor_src_cnt++] =3D page_address(src_list[i]) + offset;
> + =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 if (src_list[i]) {
> + =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =
=C2=A0 srcs[xor_src_cnt++] =3D kmap_atomic(src_list[i], KM_USER1) + offset;
> + =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 }
> + =C2=A0 =C2=A0 =C2=A0 kmap_cnt =3D xor_src_cnt;
I guess this works now that we have stack based kmap_atomic, but on
older kernels you could not simultaneously map that many buffers with
a single kmap slot. So if you resend, drop the second parameter to
kmap_atomic.
...but unless you have a non md/raid456 use case in mind, or have
patches to convert md/raid to xor straight out of the incoming biovecs
I don't think this patch is needed right?
^ permalink raw reply [flat|nested] 3+ messages in thread
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2011-12-27 6:30 [PATCH] dmaengine: async_xor, fix zero address issue when xor highmem page b29237
2012-01-11 7:51 ` Shi Xuelin-B29237
2012-01-26 9:12 ` Dan Williams
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