* [PATCH v3] ntb_transport: Limit memory windows based on available, scratchpads
@ 2016-12-02 17:46 Shyam Sundar S K
2016-12-06 7:30 ` Shyam Sundar S K
0 siblings, 1 reply; 3+ messages in thread
From: Shyam Sundar S K @ 2016-12-02 17:46 UTC (permalink / raw)
To: Jon Mason, Allen Hubbe, linux-ntb
Cc: Dave Jiang, Yu, Xiangliang, Sen, Pankaj, Shah, Nehal-bakulchandra,
Agrawal, Nitesh-kumar, Subramaniyan, Ramkumar, Su, Richard (Bin)
When the underlying NTB H/W driver advertises more memory windows
than the number of scratchpads available to setup MW's, it is likely
that we may end up filling the remaining memory windows with garbage.
So to avoid that, lets limit the memory windows that transport driver
can setup based on the available scratchpads.
Reviewed-by: Shah, Nehal-bakulchandra <Nehal-bakulchandra.Shah@amd.com>
Reviewed-by: Agrawal, Nitesh-kumar <Nitesh-kumar.Agrawal@amd.com>
Signed-off-by: S-k, Shyam-sundar <Shyam-sundar.S-k@amd.com>
---
drivers/ntb/ntb_transport.c | 24 +++++++++++++-----------
1 file changed, 13 insertions(+), 11 deletions(-)
diff --git a/drivers/ntb/ntb_transport.c b/drivers/ntb/ntb_transport.c
index 4eb8adb..e02ad4e 100644
--- a/drivers/ntb/ntb_transport.c
+++ b/drivers/ntb/ntb_transport.c
@@ -66,6 +66,7 @@
#define NTB_TRANSPORT_VER "4"
#define NTB_TRANSPORT_NAME "ntb_transport"
#define NTB_TRANSPORT_DESC "Software Queue-Pair Transport over NTB"
+#define NTB_TRANSPORT_MIN_SPADS (MW0_SZ_HIGH + 2)
MODULE_DESCRIPTION(NTB_TRANSPORT_DESC);
MODULE_VERSION(NTB_TRANSPORT_VER);
@@ -242,9 +243,6 @@ enum {
NUM_MWS,
MW0_SZ_HIGH,
MW0_SZ_LOW,
- MW1_SZ_HIGH,
- MW1_SZ_LOW,
- MAX_SPAD,
};
#define dev_client_dev(__dev) \
@@ -831,7 +829,7 @@ static void ntb_transport_link_cleanup(struct ntb_transport_ctx *nt)
* goes down, blast them now to give them a sane value the next
* time they are accessed
*/
- for (i = 0; i < MAX_SPAD; i++)
+ for (i = 0; i < ntb_spad_count(nt->ndev); i++)
ntb_spad_write(nt->ndev, i, 0);
}
@@ -1064,17 +1062,12 @@ static int ntb_transport_probe(struct ntb_client *self, struct ntb_dev *ndev)
{
struct ntb_transport_ctx *nt;
struct ntb_transport_mw *mw;
- unsigned int mw_count, qp_count;
+ unsigned int mw_count, qp_count, spad_count, max_mw_count_for_spads;
u64 qp_bitmap;
int node;
int rc, i;
mw_count = ntb_mw_count(ndev);
- if (ntb_spad_count(ndev) < (NUM_MWS + 1 + mw_count * 2)) {
- dev_err(&ndev->dev, "Not enough scratch pad registers for %s",
- NTB_TRANSPORT_NAME);
- return -EIO;
- }
if (ntb_db_is_unsafe(ndev))
dev_dbg(&ndev->dev,
@@ -1090,8 +1083,17 @@ static int ntb_transport_probe(struct ntb_client *self, struct ntb_dev *ndev)
return -ENOMEM;
nt->ndev = ndev;
+ spad_count = ntb_spad_count(ndev);
+
+ /* Limit the MW's based on the availability of scratchpads */
+
+ if (spad_count < NTB_TRANSPORT_MIN_SPADS) {
+ nt->mw_count = 0;
+ goto err;
+ }
- nt->mw_count = mw_count;
+ max_mw_count_for_spads = (spad_count - MW0_SZ_HIGH) / 2;
+ nt->mw_count = min(mw_count, max_mw_count_for_spads);
nt->mw_vec = kzalloc_node(mw_count * sizeof(*nt->mw_vec),
GFP_KERNEL, node);
--
2.7.4
^ permalink raw reply related [flat|nested] 3+ messages in thread* Re: [PATCH v3] ntb_transport: Limit memory windows based on available, scratchpads
2016-12-02 17:46 [PATCH v3] ntb_transport: Limit memory windows based on available, scratchpads Shyam Sundar S K
@ 2016-12-06 7:30 ` Shyam Sundar S K
2016-12-06 14:23 ` Allen Hubbe
0 siblings, 1 reply; 3+ messages in thread
From: Shyam Sundar S K @ 2016-12-06 7:30 UTC (permalink / raw)
To: Jon Mason, Allen Hubbe, linux-ntb
Cc: Dave Jiang, Yu, Xiangliang, Sen, Pankaj, Shah, Nehal-bakulchandra,
Agrawal, Nitesh-kumar, Subramaniyan, Ramkumar, Su, Richard (Bin)
Any feedback on the below patch ?
On 12/2/2016 11:16 PM, Shyam Sundar S K wrote:
> When the underlying NTB H/W driver advertises more memory windows
> than the number of scratchpads available to setup MW's, it is likely
> that we may end up filling the remaining memory windows with garbage.
> So to avoid that, lets limit the memory windows that transport driver
> can setup based on the available scratchpads.
>
> Reviewed-by: Shah, Nehal-bakulchandra <Nehal-bakulchandra.Shah@amd.com>
> Reviewed-by: Agrawal, Nitesh-kumar <Nitesh-kumar.Agrawal@amd.com>
> Signed-off-by: S-k, Shyam-sundar <Shyam-sundar.S-k@amd.com>
> ---
> drivers/ntb/ntb_transport.c | 24 +++++++++++++-----------
> 1 file changed, 13 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/ntb/ntb_transport.c b/drivers/ntb/ntb_transport.c
> index 4eb8adb..e02ad4e 100644
> --- a/drivers/ntb/ntb_transport.c
> +++ b/drivers/ntb/ntb_transport.c
> @@ -66,6 +66,7 @@
> #define NTB_TRANSPORT_VER "4"
> #define NTB_TRANSPORT_NAME "ntb_transport"
> #define NTB_TRANSPORT_DESC "Software Queue-Pair Transport over NTB"
> +#define NTB_TRANSPORT_MIN_SPADS (MW0_SZ_HIGH + 2)
>
> MODULE_DESCRIPTION(NTB_TRANSPORT_DESC);
> MODULE_VERSION(NTB_TRANSPORT_VER);
> @@ -242,9 +243,6 @@ enum {
> NUM_MWS,
> MW0_SZ_HIGH,
> MW0_SZ_LOW,
> - MW1_SZ_HIGH,
> - MW1_SZ_LOW,
> - MAX_SPAD,
> };
>
> #define dev_client_dev(__dev) \
> @@ -831,7 +829,7 @@ static void ntb_transport_link_cleanup(struct ntb_transport_ctx *nt)
> * goes down, blast them now to give them a sane value the next
> * time they are accessed
> */
> - for (i = 0; i < MAX_SPAD; i++)
> + for (i = 0; i < ntb_spad_count(nt->ndev); i++)
> ntb_spad_write(nt->ndev, i, 0);
> }
>
> @@ -1064,17 +1062,12 @@ static int ntb_transport_probe(struct ntb_client *self, struct ntb_dev *ndev)
> {
> struct ntb_transport_ctx *nt;
> struct ntb_transport_mw *mw;
> - unsigned int mw_count, qp_count;
> + unsigned int mw_count, qp_count, spad_count, max_mw_count_for_spads;
> u64 qp_bitmap;
> int node;
> int rc, i;
>
> mw_count = ntb_mw_count(ndev);
> - if (ntb_spad_count(ndev) < (NUM_MWS + 1 + mw_count * 2)) {
> - dev_err(&ndev->dev, "Not enough scratch pad registers for %s",
> - NTB_TRANSPORT_NAME);
> - return -EIO;
> - }
>
> if (ntb_db_is_unsafe(ndev))
> dev_dbg(&ndev->dev,
> @@ -1090,8 +1083,17 @@ static int ntb_transport_probe(struct ntb_client *self, struct ntb_dev *ndev)
> return -ENOMEM;
>
> nt->ndev = ndev;
> + spad_count = ntb_spad_count(ndev);
> +
> + /* Limit the MW's based on the availability of scratchpads */
> +
> + if (spad_count < NTB_TRANSPORT_MIN_SPADS) {
> + nt->mw_count = 0;
> + goto err;
> + }
>
> - nt->mw_count = mw_count;
> + max_mw_count_for_spads = (spad_count - MW0_SZ_HIGH) / 2;
> + nt->mw_count = min(mw_count, max_mw_count_for_spads);
>
> nt->mw_vec = kzalloc_node(mw_count * sizeof(*nt->mw_vec),
> GFP_KERNEL, node);
>
^ permalink raw reply [flat|nested] 3+ messages in thread* RE: [PATCH v3] ntb_transport: Limit memory windows based on available, scratchpads
2016-12-06 7:30 ` Shyam Sundar S K
@ 2016-12-06 14:23 ` Allen Hubbe
0 siblings, 0 replies; 3+ messages in thread
From: Allen Hubbe @ 2016-12-06 14:23 UTC (permalink / raw)
To: 'Shyam Sundar S K', 'Jon Mason', linux-ntb
Cc: 'Dave Jiang', 'Yu, Xiangliang',
'Sen, Pankaj', 'Shah, Nehal-bakulchandra',
'Agrawal, Nitesh-kumar', 'Subramaniyan, Ramkumar',
'Su, Richard (Bin)'
> Any feedback on the below patch ?
>
Except for the subject stating PATCH v3, this looks like exactly the same patch as v2. I will repeat my comment.
From: Shyam Sundar S K
> - for (i = 0; i < MAX_SPAD; i++)
> + for (i = 0; i < ntb_spad_count(nt->ndev); i++)
count = ntb_spad_count(nt->ndev);
for (i = 0; i < count; i++) ...
The rest looks good. Thanks.
> On 12/2/2016 11:16 PM, Shyam Sundar S K wrote:
> > When the underlying NTB H/W driver advertises more memory windows
> > than the number of scratchpads available to setup MW's, it is likely
> > that we may end up filling the remaining memory windows with garbage.
> > So to avoid that, lets limit the memory windows that transport driver
> > can setup based on the available scratchpads.
> >
> > Reviewed-by: Shah, Nehal-bakulchandra <Nehal-bakulchandra.Shah@amd.com>
> > Reviewed-by: Agrawal, Nitesh-kumar <Nitesh-kumar.Agrawal@amd.com>
> > Signed-off-by: S-k, Shyam-sundar <Shyam-sundar.S-k@amd.com>
> > ---
> > drivers/ntb/ntb_transport.c | 24 +++++++++++++-----------
> > 1 file changed, 13 insertions(+), 11 deletions(-)
> >
> > diff --git a/drivers/ntb/ntb_transport.c b/drivers/ntb/ntb_transport.c
> > index 4eb8adb..e02ad4e 100644
> > --- a/drivers/ntb/ntb_transport.c
> > +++ b/drivers/ntb/ntb_transport.c
> > @@ -66,6 +66,7 @@
> > #define NTB_TRANSPORT_VER "4"
> > #define NTB_TRANSPORT_NAME "ntb_transport"
> > #define NTB_TRANSPORT_DESC "Software Queue-Pair Transport over NTB"
> > +#define NTB_TRANSPORT_MIN_SPADS (MW0_SZ_HIGH + 2)
> >
> > MODULE_DESCRIPTION(NTB_TRANSPORT_DESC);
> > MODULE_VERSION(NTB_TRANSPORT_VER);
> > @@ -242,9 +243,6 @@ enum {
> > NUM_MWS,
> > MW0_SZ_HIGH,
> > MW0_SZ_LOW,
> > - MW1_SZ_HIGH,
> > - MW1_SZ_LOW,
> > - MAX_SPAD,
> > };
> >
> > #define dev_client_dev(__dev) \
> > @@ -831,7 +829,7 @@ static void ntb_transport_link_cleanup(struct ntb_transport_ctx *nt)
> > * goes down, blast them now to give them a sane value the next
> > * time they are accessed
> > */
> > - for (i = 0; i < MAX_SPAD; i++)
> > + for (i = 0; i < ntb_spad_count(nt->ndev); i++)
> > ntb_spad_write(nt->ndev, i, 0);
> > }
> >
> > @@ -1064,17 +1062,12 @@ static int ntb_transport_probe(struct ntb_client *self, struct
> ntb_dev *ndev)
> > {
> > struct ntb_transport_ctx *nt;
> > struct ntb_transport_mw *mw;
> > - unsigned int mw_count, qp_count;
> > + unsigned int mw_count, qp_count, spad_count, max_mw_count_for_spads;
> > u64 qp_bitmap;
> > int node;
> > int rc, i;
> >
> > mw_count = ntb_mw_count(ndev);
> > - if (ntb_spad_count(ndev) < (NUM_MWS + 1 + mw_count * 2)) {
> > - dev_err(&ndev->dev, "Not enough scratch pad registers for %s",
> > - NTB_TRANSPORT_NAME);
> > - return -EIO;
> > - }
> >
> > if (ntb_db_is_unsafe(ndev))
> > dev_dbg(&ndev->dev,
> > @@ -1090,8 +1083,17 @@ static int ntb_transport_probe(struct ntb_client *self, struct
> ntb_dev *ndev)
> > return -ENOMEM;
> >
> > nt->ndev = ndev;
> > + spad_count = ntb_spad_count(ndev);
> > +
> > + /* Limit the MW's based on the availability of scratchpads */
> > +
> > + if (spad_count < NTB_TRANSPORT_MIN_SPADS) {
> > + nt->mw_count = 0;
> > + goto err;
> > + }
> >
> > - nt->mw_count = mw_count;
> > + max_mw_count_for_spads = (spad_count - MW0_SZ_HIGH) / 2;
> > + nt->mw_count = min(mw_count, max_mw_count_for_spads);
> >
> > nt->mw_vec = kzalloc_node(mw_count * sizeof(*nt->mw_vec),
> > GFP_KERNEL, node);
> >
^ permalink raw reply [flat|nested] 3+ messages in thread
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2016-12-02 17:46 [PATCH v3] ntb_transport: Limit memory windows based on available, scratchpads Shyam Sundar S K
2016-12-06 7:30 ` Shyam Sundar S K
2016-12-06 14:23 ` Allen Hubbe
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