[dpdk-stable] [PATCH] net/bnxt: fix memory barriers

[dpdk-stable] [PATCH] net/bnxt: fix memory barriers

[Gavin Hu]

As there is an inclusive rte_io_wmb within the following rte_write32()
API who rings the doorbell, this makes the above rte_wmb unecessary and
remove it.

The doorbell ringing operation requires a rte_io_wmb immediately to make
it complete and visible to the device.

To read the doorbell response, which is held in the host CIO memory,
rte_cio_rmb is sufficient.

Fixes: 804e746c7b73 ("net/bnxt: add hardware resource manager init code")
Fixes: ca241d9a0952 ("net/bnxt: use I/O device memory read/write API")
Cc: stable@dpdk.org

Signed-off-by: Gavin Hu <gavin.hu@arm.com>
Reviewed-by: Steve Capper <steve.capper@arm.com>
Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>
Reviewed-by: Phil Yang <phil.yang@arm.com>
---
 drivers/net/bnxt/bnxt_hwrm.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/net/bnxt/bnxt_hwrm.c b/drivers/net/bnxt/bnxt_hwrm.c
index 9883fb5..ee07db9 100644
--- a/drivers/net/bnxt/bnxt_hwrm.c
+++ b/drivers/net/bnxt/bnxt_hwrm.c
@@ -115,9 +115,6 @@ static int bnxt_hwrm_send_message(struct bnxt *bp, void *msg,
 		data = (uint32_t *)&short_input;
 		msg_len = sizeof(short_input);
 
-		/* Sync memory write before updating doorbell */
-		rte_wmb();
-
 		max_req_len = BNXT_HWRM_SHORT_REQ_LEN;
 	}
 
@@ -137,11 +134,12 @@ static int bnxt_hwrm_send_message(struct bnxt *bp, void *msg,
 	/* Ring channel doorbell */
 	bar = (uint8_t *)bp->bar0 + mb_trigger_offset;
 	rte_write32(1, bar);
+	rte_io_wmb();
 
 	/* Poll for the valid bit */
 	for (i = 0; i < HWRM_CMD_TIMEOUT; i++) {
 		/* Sanity check on the resp->resp_len */
-		rte_rmb();
+		rte_cio_rmb();
 		if (resp->resp_len && resp->resp_len <= bp->max_resp_len) {
 			/* Last byte of resp contains the valid key */
 			valid = (uint8_t *)resp + resp->resp_len - 1;
-- 
2.7.4

[dpdk-stable] [PATCH v2 3/5] net/bnxt: remove duplicate barrier

[Gavin Hu]

As there is an inclusive rte_io_wmb within the following rte_write32()
API who rings the doorbell, this makes the above rte_wmb unnecessary and
remove it.

Fixes: 1cd45aeb3270 ("net/bnxt: support Stratus VF device")
Cc: stable@dpdk.org

Signed-off-by: Gavin Hu <gavin.hu@arm.com>
Reviewed-by: Steve Capper <steve.capper@arm.com>
Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>
Reviewed-by: Phil Yang <phil.yang@arm.com>
---
 drivers/net/bnxt/bnxt_hwrm.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/drivers/net/bnxt/bnxt_hwrm.c b/drivers/net/bnxt/bnxt_hwrm.c
index 9883fb5..1d9fb17 100644
--- a/drivers/net/bnxt/bnxt_hwrm.c
+++ b/drivers/net/bnxt/bnxt_hwrm.c
@@ -115,9 +115,6 @@ static int bnxt_hwrm_send_message(struct bnxt *bp, void *msg,
 		data = (uint32_t *)&short_input;
 		msg_len = sizeof(short_input);
 
-		/* Sync memory write before updating doorbell */
-		rte_wmb();
-
 		max_req_len = BNXT_HWRM_SHORT_REQ_LEN;
 	}
 
-- 
2.7.4

Re: [dpdk-stable] [PATCH v2 3/5] net/bnxt: remove duplicate barrier

[Ajit Khaparde]

On Mon, Sep 16, 2019 at 4:27 AM Gavin Hu <gavin.hu@arm.com> wrote:

> As there is an inclusive rte_io_wmb within the following rte_write32()
> API who rings the doorbell, this makes the above rte_wmb unnecessary and
> remove it.
>
> Fixes: 1cd45aeb3270 ("net/bnxt: support Stratus VF device")
> Cc: stable@dpdk.org
>
> Signed-off-by: Gavin Hu <gavin.hu@arm.com>
> Reviewed-by: Steve Capper <steve.capper@arm.com>
> Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>
> Reviewed-by: Phil Yang <phil.yang@arm.com>
>

Acked-by: Ajit Khaparde <ajit.khaparde@broadcom.com>


> ---
>  drivers/net/bnxt/bnxt_hwrm.c | 3 ---
>  1 file changed, 3 deletions(-)
>
> diff --git a/drivers/net/bnxt/bnxt_hwrm.c b/drivers/net/bnxt/bnxt_hwrm.c
> index 9883fb5..1d9fb17 100644
> --- a/drivers/net/bnxt/bnxt_hwrm.c
> +++ b/drivers/net/bnxt/bnxt_hwrm.c
> @@ -115,9 +115,6 @@ static int bnxt_hwrm_send_message(struct bnxt *bp,
> void *msg,
>                 data = (uint32_t *)&short_input;
>                 msg_len = sizeof(short_input);
>
> -               /* Sync memory write before updating doorbell */
> -               rte_wmb();
> -
>                 max_req_len = BNXT_HWRM_SHORT_REQ_LEN;
>         }
>
> --
> 2.7.4
>
>

[dpdk-stable] [PATCH v2 4/5] net/bnxt: replace with cio barrier for doorbell resp

[Gavin Hu]

To read the doorbell response, which is held in the host CIO memory,
rte_cio_rmb is sufficient.

Fixes: 804e746c7b73 ("net/bnxt: add hardware resource manager init code")
Cc: stable@dpdk.org

Signed-off-by: Gavin Hu <gavin.hu@arm.com>
---
 drivers/net/bnxt/bnxt_hwrm.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/bnxt/bnxt_hwrm.c b/drivers/net/bnxt/bnxt_hwrm.c
index 1d9fb17..2d5dc00 100644
--- a/drivers/net/bnxt/bnxt_hwrm.c
+++ b/drivers/net/bnxt/bnxt_hwrm.c
@@ -138,7 +138,7 @@ static int bnxt_hwrm_send_message(struct bnxt *bp, void *msg,
 	/* Poll for the valid bit */
 	for (i = 0; i < HWRM_CMD_TIMEOUT; i++) {
 		/* Sanity check on the resp->resp_len */
-		rte_rmb();
+		rte_cio_rmb();
 		if (resp->resp_len && resp->resp_len <= bp->max_resp_len) {
 			/* Last byte of resp contains the valid key */
 			valid = (uint8_t *)resp + resp->resp_len - 1;
-- 
2.7.4

Re: [dpdk-stable] [PATCH v2 4/5] net/bnxt: replace with cio barrier for doorbell resp

[Ajit Khaparde]

On Mon, Sep 16, 2019 at 4:27 AM Gavin Hu <gavin.hu@arm.com> wrote:

> To read the doorbell response, which is held in the host CIO memory,
> rte_cio_rmb is sufficient.
>
> Fixes: 804e746c7b73 ("net/bnxt: add hardware resource manager init code")
> Cc: stable@dpdk.org
>
> Signed-off-by: Gavin Hu <gavin.hu@arm.com>
>
Acked-by: Ajit Khaparde <ajit.khaparde@broadcom.com>


> ---
>  drivers/net/bnxt/bnxt_hwrm.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/net/bnxt/bnxt_hwrm.c b/drivers/net/bnxt/bnxt_hwrm.c
> index 1d9fb17..2d5dc00 100644
> --- a/drivers/net/bnxt/bnxt_hwrm.c
> +++ b/drivers/net/bnxt/bnxt_hwrm.c
> @@ -138,7 +138,7 @@ static int bnxt_hwrm_send_message(struct bnxt *bp,
> void *msg,
>         /* Poll for the valid bit */
>         for (i = 0; i < HWRM_CMD_TIMEOUT; i++) {
>                 /* Sanity check on the resp->resp_len */
> -               rte_rmb();
> +               rte_cio_rmb();
>                 if (resp->resp_len && resp->resp_len <= bp->max_resp_len) {
>                         /* Last byte of resp contains the valid key */
>                         valid = (uint8_t *)resp + resp->resp_len - 1;
> --
> 2.7.4
>
>

[dpdk-stable] [PATCH v2 5/5] net/bnxt: enforce io barrier for doorbell command

[Gavin Hu]

The doorbell ringing operation requires a rte_io_mb immediately to make
the command complete and visible to the device before reading the
response, otherwise it may read stale or invalid responses.

Fixes: ca241d9a0952 ("net/bnxt: use I/O device memory read/write API")
Cc: stable@dpdk.org

Signed-off-by: Gavin Hu <gavin.hu@arm.com>
---
 drivers/net/bnxt/bnxt_hwrm.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/net/bnxt/bnxt_hwrm.c b/drivers/net/bnxt/bnxt_hwrm.c
index 2d5dc00..7d192e3 100644
--- a/drivers/net/bnxt/bnxt_hwrm.c
+++ b/drivers/net/bnxt/bnxt_hwrm.c
@@ -134,6 +134,12 @@ static int bnxt_hwrm_send_message(struct bnxt *bp, void *msg,
 	/* Ring channel doorbell */
 	bar = (uint8_t *)bp->bar0 + mb_trigger_offset;
 	rte_write32(1, bar);
+	/*
+	 * Make sure the channel doorbell ring command complete before
+	 * reading the response to avoid getting stale or invalid
+	 * responses.
+	 */
+	rte_io_mb();
 
 	/* Poll for the valid bit */
 	for (i = 0; i < HWRM_CMD_TIMEOUT; i++) {
-- 
2.7.4

Re: [dpdk-stable] [PATCH v2 5/5] net/bnxt: enforce io barrier for doorbell command

[Ajit Khaparde]

On Mon, Sep 16, 2019 at 4:27 AM Gavin Hu <gavin.hu@arm.com> wrote:

> The doorbell ringing operation requires a rte_io_mb immediately to make
> the command complete and visible to the device before reading the
> response, otherwise it may read stale or invalid responses.
>
> Fixes: ca241d9a0952 ("net/bnxt: use I/O device memory read/write API")
> Cc: stable@dpdk.org
>
> Signed-off-by: Gavin Hu <gavin.hu@arm.com>
>
Acked-by: Ajit Khaparde <ajit.khaparde@broadcom.com>


> ---
>  drivers/net/bnxt/bnxt_hwrm.c | 6 ++++++
>  1 file changed, 6 insertions(+)
>
> diff --git a/drivers/net/bnxt/bnxt_hwrm.c b/drivers/net/bnxt/bnxt_hwrm.c
> index 2d5dc00..7d192e3 100644
> --- a/drivers/net/bnxt/bnxt_hwrm.c
> +++ b/drivers/net/bnxt/bnxt_hwrm.c
> @@ -134,6 +134,12 @@ static int bnxt_hwrm_send_message(struct bnxt *bp,
> void *msg,
>         /* Ring channel doorbell */
>         bar = (uint8_t *)bp->bar0 + mb_trigger_offset;
>         rte_write32(1, bar);
> +       /*
> +        * Make sure the channel doorbell ring command complete before
> +        * reading the response to avoid getting stale or invalid
> +        * responses.
> +        */
> +       rte_io_mb();
>
>         /* Poll for the valid bit */
>         for (i = 0; i < HWRM_CMD_TIMEOUT; i++) {
> --
> 2.7.4
>
>