* [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; +Cc: vinod.koul, linuxppc-dev, linux-kernel, Li Yang-R58472
Hello Dan Williams,
Do you have any comment about this patch?
Thanks,
Forrest
-----Original Message-----
From: Shi Xuelin-B29237
Sent: 2011年12月27日 14:31
To: vinod.koul@intel.com; dan.j.williams@intel.com; linuxppc-dev@lists.ozlabs.org; linux-kernel@vger.kernel.org; Li Yang-R58472
Cc: Shi Xuelin-B29237
Subject: [PATCH] dmaengine: async_xor, fix zero address issue when xor highmem 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 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 [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, linuxppc-dev, linux-kernel, 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年12月27日 14:31
> To: vinod.koul@intel.com; dan.j.williams@intel.com; linuxppc-dev@lists.ozlabs.org; linux-kernel@vger.kernel.org; Li Yang-R58472
> Cc: Shi Xuelin-B29237
> Subject: [PATCH] dmaengine: async_xor, fix zero address issue when xor highmem 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.
In what scenarios do we xor highmem?
In the case of raid we currently always xor on kmalloc'd memory.
>
> 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;
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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