2023-04-10 10:13:07

by Song, Yoong Siang

[permalink] [raw]
Subject: [PATCH net-next 0/4] XDP Rx HWTS metadata for stmmac driver

Implemented XDP receive hardware timestamp metadata for stmmac driver.

This patchset is tested with tools/testing/selftests/bpf/xdp_hw_metadata.
Below are the test steps and results.

Command on DUT:
sudo ./xdp_hw_metadata <interface name>

Command on Link Partner:
echo -n xdp | nc -u -q1 <destination IPv4 addr> 9091
echo -n skb | nc -u -q1 <destination IPv4 addr> 9092

Result for port 9091:
0x55fdb5f006d0: rx_desc[3]->addr=1000000003bd000 addr=3bd100 comp_addr=3bd000
rx_timestamp: 1677762474360150047
rx_hash: 0
0x55fdb5f006d0: complete idx=515 addr=3bd000

Result for port 9092:
found skb hwtstamp = 1677762476.320146161

---

Ong Boon Leong (1):
net: stmmac: restructure Rx hardware timestamping function

Song Yoong Siang (3):
net: stmmac: introduce wrapper for struct xdp_buff
net: stmmac: add Rx HWTS metadata to XDP receive pkt
net: stmmac: add Rx HWTS metadata to XDP ZC receive pkt

drivers/net/ethernet/stmicro/stmmac/stmmac.h | 5 ++
.../net/ethernet/stmicro/stmmac/stmmac_main.c | 88 ++++++++++++++-----
2 files changed, 73 insertions(+), 20 deletions(-)

--
2.34.1


2023-04-10 10:14:57

by Song, Yoong Siang

[permalink] [raw]
Subject: [PATCH net-next 1/4] net: stmmac: restructure Rx hardware timestamping function

From: Ong Boon Leong <[email protected]>

Rearrange the function of getting Rx hardware timestamp for skb so
that it can be reused for XDP later.

Signed-off-by: Ong Boon Leong <[email protected]>
Signed-off-by: Song Yoong Siang <[email protected]>
---
.../net/ethernet/stmicro/stmmac/stmmac_main.c | 21 ++++++++++++-------
1 file changed, 13 insertions(+), 8 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 04fbb7770618..2cc6237a9c28 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -570,15 +570,14 @@ static void stmmac_get_tx_hwtstamp(struct stmmac_priv *priv,
* @priv: driver private structure
* @p : descriptor pointer
* @np : next descriptor pointer
- * @skb : the socket buffer
+ * @hwtstamp : hardware timestamp
* Description :
* This function will read received packet's timestamp from the descriptor
* and pass it to stack. It also perform some sanity checks.
*/
static void stmmac_get_rx_hwtstamp(struct stmmac_priv *priv, struct dma_desc *p,
- struct dma_desc *np, struct sk_buff *skb)
+ struct dma_desc *np, ktime_t *hwtstamp)
{
- struct skb_shared_hwtstamps *shhwtstamp = NULL;
struct dma_desc *desc = p;
u64 ns = 0;

@@ -595,9 +594,7 @@ static void stmmac_get_rx_hwtstamp(struct stmmac_priv *priv, struct dma_desc *p,
ns -= priv->plat->cdc_error_adj;

netdev_dbg(priv->dev, "get valid RX hw timestamp %llu\n", ns);
- shhwtstamp = skb_hwtstamps(skb);
- memset(shhwtstamp, 0, sizeof(struct skb_shared_hwtstamps));
- shhwtstamp->hwtstamp = ns_to_ktime(ns);
+ *hwtstamp = ns_to_ktime(ns);
} else {
netdev_dbg(priv->dev, "cannot get RX hw timestamp\n");
}
@@ -4909,6 +4906,7 @@ static void stmmac_dispatch_skb_zc(struct stmmac_priv *priv, u32 queue,
struct xdp_buff *xdp)
{
struct stmmac_channel *ch = &priv->channel[queue];
+ struct skb_shared_hwtstamps *shhwtstamp = NULL;
unsigned int len = xdp->data_end - xdp->data;
enum pkt_hash_types hash_type;
int coe = priv->hw->rx_csum;
@@ -4921,7 +4919,10 @@ static void stmmac_dispatch_skb_zc(struct stmmac_priv *priv, u32 queue,
return;
}

- stmmac_get_rx_hwtstamp(priv, p, np, skb);
+ shhwtstamp = skb_hwtstamps(skb);
+ memset(shhwtstamp, 0, sizeof(struct skb_shared_hwtstamps));
+ stmmac_get_rx_hwtstamp(priv, p, np, &shhwtstamp->hwtstamp);
+
stmmac_rx_vlan(priv->dev, skb);
skb->protocol = eth_type_trans(skb, priv->dev);

@@ -5213,6 +5214,7 @@ static int stmmac_rx(struct stmmac_priv *priv, int limit, u32 queue)
rx_q->dma_rx_phy, desc_size);
}
while (count < limit) {
+ struct skb_shared_hwtstamps *shhwtstamp = NULL;
unsigned int buf1_len = 0, buf2_len = 0;
enum pkt_hash_types hash_type;
struct stmmac_rx_buffer *buf;
@@ -5407,7 +5409,10 @@ static int stmmac_rx(struct stmmac_priv *priv, int limit, u32 queue)

/* Got entire packet into SKB. Finish it. */

- stmmac_get_rx_hwtstamp(priv, p, np, skb);
+ shhwtstamp = skb_hwtstamps(skb);
+ memset(shhwtstamp, 0, sizeof(struct skb_shared_hwtstamps));
+ stmmac_get_rx_hwtstamp(priv, p, np, &shhwtstamp->hwtstamp);
+
stmmac_rx_vlan(priv->dev, skb);
skb->protocol = eth_type_trans(skb, priv->dev);

--
2.34.1

2023-04-10 10:16:51

by Song, Yoong Siang

[permalink] [raw]
Subject: [PATCH net-next 2/4] net: stmmac: introduce wrapper for struct xdp_buff

Introduce struct stmmac_xdp_buff as a preparation to support XDP Rx
metadata via kfuncs.

Signed-off-by: Song Yoong Siang <[email protected]>
---
drivers/net/ethernet/stmicro/stmmac/stmmac.h | 4 ++++
.../net/ethernet/stmicro/stmmac/stmmac_main.c | 18 +++++++++---------
2 files changed, 13 insertions(+), 9 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac.h b/drivers/net/ethernet/stmicro/stmmac/stmmac.h
index 3d15e1e92e18..ac8ccf851708 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac.h
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac.h
@@ -92,6 +92,10 @@ struct stmmac_rx_buffer {
dma_addr_t sec_addr;
};

+struct stmmac_xdp_buff {
+ struct xdp_buff xdp;
+};
+
struct stmmac_rx_queue {
u32 rx_count_frames;
u32 queue_index;
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 2cc6237a9c28..f7bbdf04d20c 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -5189,9 +5189,9 @@ static int stmmac_rx(struct stmmac_priv *priv, int limit, u32 queue)
int status = 0, coe = priv->hw->rx_csum;
unsigned int next_entry = rx_q->cur_rx;
enum dma_data_direction dma_dir;
+ struct stmmac_xdp_buff ctx = {};
unsigned int desc_size;
struct sk_buff *skb = NULL;
- struct xdp_buff xdp;
int xdp_status = 0;
int buf_sz;

@@ -5313,17 +5313,17 @@ static int stmmac_rx(struct stmmac_priv *priv, int limit, u32 queue)
dma_sync_single_for_cpu(priv->device, buf->addr,
buf1_len, dma_dir);

- xdp_init_buff(&xdp, buf_sz, &rx_q->xdp_rxq);
- xdp_prepare_buff(&xdp, page_address(buf->page),
+ xdp_init_buff(&ctx.xdp, buf_sz, &rx_q->xdp_rxq);
+ xdp_prepare_buff(&ctx.xdp, page_address(buf->page),
buf->page_offset, buf1_len, false);

- pre_len = xdp.data_end - xdp.data_hard_start -
+ pre_len = ctx.xdp.data_end - ctx.xdp.data_hard_start -
buf->page_offset;
- skb = stmmac_xdp_run_prog(priv, &xdp);
+ skb = stmmac_xdp_run_prog(priv, &ctx.xdp);
/* Due xdp_adjust_tail: DMA sync for_device
* cover max len CPU touch
*/
- sync_len = xdp.data_end - xdp.data_hard_start -
+ sync_len = ctx.xdp.data_end - ctx.xdp.data_hard_start -
buf->page_offset;
sync_len = max(sync_len, pre_len);

@@ -5333,7 +5333,7 @@ static int stmmac_rx(struct stmmac_priv *priv, int limit, u32 queue)

if (xdp_res & STMMAC_XDP_CONSUMED) {
page_pool_put_page(rx_q->page_pool,
- virt_to_head_page(xdp.data),
+ virt_to_head_page(ctx.xdp.data),
sync_len, true);
buf->page = NULL;
priv->dev->stats.rx_dropped++;
@@ -5361,7 +5361,7 @@ static int stmmac_rx(struct stmmac_priv *priv, int limit, u32 queue)

if (!skb) {
/* XDP program may expand or reduce tail */
- buf1_len = xdp.data_end - xdp.data;
+ buf1_len = ctx.xdp.data_end - ctx.xdp.data;

skb = napi_alloc_skb(&ch->rx_napi, buf1_len);
if (!skb) {
@@ -5371,7 +5371,7 @@ static int stmmac_rx(struct stmmac_priv *priv, int limit, u32 queue)
}

/* XDP program may adjust header */
- skb_copy_to_linear_data(skb, xdp.data, buf1_len);
+ skb_copy_to_linear_data(skb, ctx.xdp.data, buf1_len);
skb_put(skb, buf1_len);

/* Data payload copied into SKB, page ready for recycle */
--
2.34.1

2023-04-10 10:21:52

by Song, Yoong Siang

[permalink] [raw]
Subject: [PATCH net-next 3/4] net: stmmac: add Rx HWTS metadata to XDP receive pkt

Add receive hardware timestamp metadata support via kfunc to XDP receive
packets.

Signed-off-by: Song Yoong Siang <[email protected]>
---
drivers/net/ethernet/stmicro/stmmac/stmmac.h | 1 +
.../net/ethernet/stmicro/stmmac/stmmac_main.c | 24 +++++++++++++++++--
2 files changed, 23 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac.h b/drivers/net/ethernet/stmicro/stmmac/stmmac.h
index ac8ccf851708..760445275da8 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac.h
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac.h
@@ -94,6 +94,7 @@ struct stmmac_rx_buffer {

struct stmmac_xdp_buff {
struct xdp_buff xdp;
+ ktime_t rx_hwts;
};

struct stmmac_rx_queue {
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index f7bbdf04d20c..ca183fbfde85 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -5307,6 +5307,8 @@ static int stmmac_rx(struct stmmac_priv *priv, int limit, u32 queue)
}
}

+ stmmac_get_rx_hwtstamp(priv, p, np, &ctx.rx_hwts);
+
if (!skb) {
unsigned int pre_len, sync_len;

@@ -5315,7 +5317,7 @@ static int stmmac_rx(struct stmmac_priv *priv, int limit, u32 queue)

xdp_init_buff(&ctx.xdp, buf_sz, &rx_q->xdp_rxq);
xdp_prepare_buff(&ctx.xdp, page_address(buf->page),
- buf->page_offset, buf1_len, false);
+ buf->page_offset, buf1_len, true);

pre_len = ctx.xdp.data_end - ctx.xdp.data_hard_start -
buf->page_offset;
@@ -5411,7 +5413,7 @@ static int stmmac_rx(struct stmmac_priv *priv, int limit, u32 queue)

shhwtstamp = skb_hwtstamps(skb);
memset(shhwtstamp, 0, sizeof(struct skb_shared_hwtstamps));
- stmmac_get_rx_hwtstamp(priv, p, np, &shhwtstamp->hwtstamp);
+ shhwtstamp->hwtstamp = ctx.rx_hwts;

stmmac_rx_vlan(priv->dev, skb);
skb->protocol = eth_type_trans(skb, priv->dev);
@@ -7071,6 +7073,22 @@ void stmmac_fpe_handshake(struct stmmac_priv *priv, bool enable)
}
}

+static int stmmac_xdp_rx_timestamp(const struct xdp_md *_ctx, u64 *timestamp)
+{
+ const struct stmmac_xdp_buff *ctx = (void *)_ctx;
+
+ if (ctx->rx_hwts) {
+ *timestamp = ctx->rx_hwts;
+ return 0;
+ }
+
+ return -ENODATA;
+}
+
+const struct xdp_metadata_ops stmmac_xdp_metadata_ops = {
+ .xmo_rx_timestamp = stmmac_xdp_rx_timestamp,
+};
+
/**
* stmmac_dvr_probe
* @device: device pointer
@@ -7178,6 +7196,8 @@ int stmmac_dvr_probe(struct device *device,

ndev->netdev_ops = &stmmac_netdev_ops;

+ ndev->xdp_metadata_ops = &stmmac_xdp_metadata_ops;
+
ndev->hw_features = NETIF_F_SG | NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM |
NETIF_F_RXCSUM;
ndev->xdp_features = NETDEV_XDP_ACT_BASIC | NETDEV_XDP_ACT_REDIRECT |
--
2.34.1

2023-04-10 10:24:01

by Song, Yoong Siang

[permalink] [raw]
Subject: [PATCH net-next 4/4] net: stmmac: add Rx HWTS metadata to XDP ZC receive pkt

Add receive hardware timestamp metadata support via kfunc to XDP Zero Copy
receive packets.

Signed-off-by: Song Yoong Siang <[email protected]>
---
.../net/ethernet/stmicro/stmmac/stmmac_main.c | 29 +++++++++++++++++--
1 file changed, 26 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index ca183fbfde85..a4545e9eb8fd 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -1611,6 +1611,12 @@ static int stmmac_alloc_rx_buffers_zc(struct stmmac_priv *priv,
struct stmmac_rx_queue *rx_q = &dma_conf->rx_queue[queue];
int i;

+ /* struct stmmac_xdp_buff is using cb field (maximum size of 24 bytes)
+ * in struct xdp_buff_xsk to stash driver specific information. Thus,
+ * use this macro to make sure no size violations.
+ */
+ XSK_CHECK_PRIV_TYPE(struct stmmac_xdp_buff);
+
for (i = 0; i < dma_conf->dma_rx_size; i++) {
struct stmmac_rx_buffer *buf;
dma_addr_t dma_addr;
@@ -4903,7 +4909,7 @@ static struct sk_buff *stmmac_construct_skb_zc(struct stmmac_channel *ch,

static void stmmac_dispatch_skb_zc(struct stmmac_priv *priv, u32 queue,
struct dma_desc *p, struct dma_desc *np,
- struct xdp_buff *xdp)
+ struct xdp_buff *xdp, ktime_t rx_hwts)
{
struct stmmac_channel *ch = &priv->channel[queue];
struct skb_shared_hwtstamps *shhwtstamp = NULL;
@@ -4921,7 +4927,7 @@ static void stmmac_dispatch_skb_zc(struct stmmac_priv *priv, u32 queue,

shhwtstamp = skb_hwtstamps(skb);
memset(shhwtstamp, 0, sizeof(struct skb_shared_hwtstamps));
- stmmac_get_rx_hwtstamp(priv, p, np, &shhwtstamp->hwtstamp);
+ shhwtstamp->hwtstamp = rx_hwts;

stmmac_rx_vlan(priv->dev, skb);
skb->protocol = eth_type_trans(skb, priv->dev);
@@ -4999,6 +5005,16 @@ static bool stmmac_rx_refill_zc(struct stmmac_priv *priv, u32 queue, u32 budget)
return ret;
}

+static struct stmmac_xdp_buff *xsk_buff_to_stmmac_ctx(struct xdp_buff *xdp)
+{
+ /* In XDP zero copy data path, xdp field in struct xdp_buff_xsk is used
+ * to represent incoming packet, whereas cb field in the same structure
+ * is used to store driver specific info. Thus, struct stmmac_xdp_buff
+ * is laid on top of xdp and cb fields of struct xdp_buff_xsk.
+ */
+ return (struct stmmac_xdp_buff *)xdp;
+}
+
static int stmmac_rx_zc(struct stmmac_priv *priv, int limit, u32 queue)
{
struct stmmac_rx_queue *rx_q = &priv->dma_conf.rx_queue[queue];
@@ -5028,8 +5044,10 @@ static int stmmac_rx_zc(struct stmmac_priv *priv, int limit, u32 queue)
}
while (count < limit) {
struct stmmac_rx_buffer *buf;
+ struct stmmac_xdp_buff *ctx;
unsigned int buf1_len = 0;
struct dma_desc *np, *p;
+ ktime_t rx_hwts = 0;
int entry;
int res;

@@ -5113,6 +5131,10 @@ static int stmmac_rx_zc(struct stmmac_priv *priv, int limit, u32 queue)
goto read_again;
}

+ stmmac_get_rx_hwtstamp(priv, p, np, &rx_hwts);
+ ctx = xsk_buff_to_stmmac_ctx(buf->xdp);
+ ctx->rx_hwts = rx_hwts;
+
/* XDP ZC Frame only support primary buffers for now */
buf1_len = stmmac_rx_buf1_len(priv, p, status, len);
len += buf1_len;
@@ -5132,7 +5154,8 @@ static int stmmac_rx_zc(struct stmmac_priv *priv, int limit, u32 queue)

switch (res) {
case STMMAC_XDP_PASS:
- stmmac_dispatch_skb_zc(priv, queue, p, np, buf->xdp);
+ stmmac_dispatch_skb_zc(priv, queue, p, np, buf->xdp,
+ rx_hwts);
xsk_buff_free(buf->xdp);
break;
case STMMAC_XDP_CONSUMED:
--
2.34.1

2023-04-10 14:20:43

by Simon Horman

[permalink] [raw]
Subject: Re: [PATCH net-next 3/4] net: stmmac: add Rx HWTS metadata to XDP receive pkt

On Mon, Apr 10, 2023 at 06:09:38PM +0800, Song Yoong Siang wrote:
> Add receive hardware timestamp metadata support via kfunc to XDP receive
> packets.
>
> Signed-off-by: Song Yoong Siang <[email protected]>

...

> @@ -7071,6 +7073,22 @@ void stmmac_fpe_handshake(struct stmmac_priv *priv, bool enable)
> }
> }
>
> +static int stmmac_xdp_rx_timestamp(const struct xdp_md *_ctx, u64 *timestamp)
> +{
> + const struct stmmac_xdp_buff *ctx = (void *)_ctx;
> +
> + if (ctx->rx_hwts) {
> + *timestamp = ctx->rx_hwts;
> + return 0;
> + }
> +
> + return -ENODATA;
> +}
> +
> +const struct xdp_metadata_ops stmmac_xdp_metadata_ops = {
> + .xmo_rx_timestamp = stmmac_xdp_rx_timestamp,
> +};

sparse seems to think this should be static.

drivers/net/ethernet/stmicro/stmmac/stmmac_main.c:7082:31: warning: symbol 'stmmac_xdp_metadata_ops' was not declared. Should it be static?

Link: https://patchwork.kernel.org/project/netdevbpf/patch/[email protected]/

> +
> /**
> * stmmac_dvr_probe
> * @device: device pointer

2023-04-10 15:38:56

by Song, Yoong Siang

[permalink] [raw]
Subject: RE: [PATCH net-next 3/4] net: stmmac: add Rx HWTS metadata to XDP receive pkt

>On Mon, Apr 10, 2023 at 06:09:38PM +0800, Song Yoong Siang wrote:
>> Add receive hardware timestamp metadata support via kfunc to XDP
>> receive packets.
>>
>> Signed-off-by: Song Yoong Siang <[email protected]>
>
>...
>
>> @@ -7071,6 +7073,22 @@ void stmmac_fpe_handshake(struct stmmac_priv
>*priv, bool enable)
>> }
>> }
>>
>> +static int stmmac_xdp_rx_timestamp(const struct xdp_md *_ctx, u64
>> +*timestamp) {
>> + const struct stmmac_xdp_buff *ctx = (void *)_ctx;
>> +
>> + if (ctx->rx_hwts) {
>> + *timestamp = ctx->rx_hwts;
>> + return 0;
>> + }
>> +
>> + return -ENODATA;
>> +}
>> +
>> +const struct xdp_metadata_ops stmmac_xdp_metadata_ops = {
>> + .xmo_rx_timestamp = stmmac_xdp_rx_timestamp,
>> +};
>
>sparse seems to think this should be static.
>
>drivers/net/ethernet/stmicro/stmmac/stmmac_main.c:7082:31: warning: symbol
>'stmmac_xdp_metadata_ops' was not declared. Should it be static?
Yes, you are right. It should be static. I will add correct it in v2. Thank you.

Thanks & Regards
Siang
>
>Link:
>https://patchwork.kernel.org/project/netdevbpf/patch/20230410100939.331833
>[email protected]/
>
>> +
>> /**
>> * stmmac_dvr_probe
>> * @device: device pointer

2023-04-10 16:29:32

by Stanislav Fomichev

[permalink] [raw]
Subject: Re: [PATCH net-next 3/4] net: stmmac: add Rx HWTS metadata to XDP receive pkt

On 04/10, Song Yoong Siang wrote:
> Add receive hardware timestamp metadata support via kfunc to XDP receive
> packets.
>
> Signed-off-by: Song Yoong Siang <[email protected]>
> ---
> drivers/net/ethernet/stmicro/stmmac/stmmac.h | 1 +
> .../net/ethernet/stmicro/stmmac/stmmac_main.c | 24 +++++++++++++++++--
> 2 files changed, 23 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac.h b/drivers/net/ethernet/stmicro/stmmac/stmmac.h
> index ac8ccf851708..760445275da8 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac.h
> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac.h
> @@ -94,6 +94,7 @@ struct stmmac_rx_buffer {
>
> struct stmmac_xdp_buff {
> struct xdp_buff xdp;
> + ktime_t rx_hwts;
> };
>
> struct stmmac_rx_queue {
> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> index f7bbdf04d20c..ca183fbfde85 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> @@ -5307,6 +5307,8 @@ static int stmmac_rx(struct stmmac_priv *priv, int limit, u32 queue)
> }
> }
>

[..]

> + stmmac_get_rx_hwtstamp(priv, p, np, &ctx.rx_hwts);

Do we want to pay this cost for every packet?

The preferred alternative is to store enough state in the
stmmac_xdp_buff so we can get to this data from stmmac_xdp_rx_timestamp.

I haven't read this code, but tentatively:
- move priv, p, np into stmmac_xdp_buff, assign them here instead of
calling stmmac_get_rx_hwtstamp
- call stmmac_get_rx_hwtstamp from stmmac_xdp_rx_timestamp with the
stored priv, p, np

That would ensure that we won't waste the cycles pulling out the rx
timestamp for every packet if the higher levels / users don't care.

Would something like this work?

> +
> if (!skb) {
> unsigned int pre_len, sync_len;
>
> @@ -5315,7 +5317,7 @@ static int stmmac_rx(struct stmmac_priv *priv, int limit, u32 queue)
>
> xdp_init_buff(&ctx.xdp, buf_sz, &rx_q->xdp_rxq);
> xdp_prepare_buff(&ctx.xdp, page_address(buf->page),
> - buf->page_offset, buf1_len, false);
> + buf->page_offset, buf1_len, true);
>
> pre_len = ctx.xdp.data_end - ctx.xdp.data_hard_start -
> buf->page_offset;
> @@ -5411,7 +5413,7 @@ static int stmmac_rx(struct stmmac_priv *priv, int limit, u32 queue)
>
> shhwtstamp = skb_hwtstamps(skb);
> memset(shhwtstamp, 0, sizeof(struct skb_shared_hwtstamps));
> - stmmac_get_rx_hwtstamp(priv, p, np, &shhwtstamp->hwtstamp);
> + shhwtstamp->hwtstamp = ctx.rx_hwts;
>
> stmmac_rx_vlan(priv->dev, skb);
> skb->protocol = eth_type_trans(skb, priv->dev);
> @@ -7071,6 +7073,22 @@ void stmmac_fpe_handshake(struct stmmac_priv *priv, bool enable)
> }
> }
>
> +static int stmmac_xdp_rx_timestamp(const struct xdp_md *_ctx, u64 *timestamp)
> +{
> + const struct stmmac_xdp_buff *ctx = (void *)_ctx;
> +
> + if (ctx->rx_hwts) {
> + *timestamp = ctx->rx_hwts;
> + return 0;
> + }
> +
> + return -ENODATA;
> +}
> +
> +const struct xdp_metadata_ops stmmac_xdp_metadata_ops = {
> + .xmo_rx_timestamp = stmmac_xdp_rx_timestamp,
> +};
> +
> /**
> * stmmac_dvr_probe
> * @device: device pointer
> @@ -7178,6 +7196,8 @@ int stmmac_dvr_probe(struct device *device,
>
> ndev->netdev_ops = &stmmac_netdev_ops;
>
> + ndev->xdp_metadata_ops = &stmmac_xdp_metadata_ops;
> +
> ndev->hw_features = NETIF_F_SG | NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM |
> NETIF_F_RXCSUM;
> ndev->xdp_features = NETDEV_XDP_ACT_BASIC | NETDEV_XDP_ACT_REDIRECT |
> --
> 2.34.1
>

2023-04-10 18:13:27

by Simon Horman

[permalink] [raw]
Subject: Re: [PATCH net-next 3/4] net: stmmac: add Rx HWTS metadata to XDP receive pkt

On Mon, Apr 10, 2023 at 03:33:48PM +0000, Song, Yoong Siang wrote:
> >On Mon, Apr 10, 2023 at 06:09:38PM +0800, Song Yoong Siang wrote:
> >> Add receive hardware timestamp metadata support via kfunc to XDP
> >> receive packets.
> >>
> >> Signed-off-by: Song Yoong Siang <[email protected]>
> >
> >...
> >
> >> @@ -7071,6 +7073,22 @@ void stmmac_fpe_handshake(struct stmmac_priv
> >*priv, bool enable)
> >> }
> >> }
> >>
> >> +static int stmmac_xdp_rx_timestamp(const struct xdp_md *_ctx, u64
> >> +*timestamp) {
> >> + const struct stmmac_xdp_buff *ctx = (void *)_ctx;
> >> +
> >> + if (ctx->rx_hwts) {
> >> + *timestamp = ctx->rx_hwts;
> >> + return 0;
> >> + }
> >> +
> >> + return -ENODATA;
> >> +}
> >> +
> >> +const struct xdp_metadata_ops stmmac_xdp_metadata_ops = {
> >> + .xmo_rx_timestamp = stmmac_xdp_rx_timestamp,
> >> +};
> >
> >sparse seems to think this should be static.
> >
> >drivers/net/ethernet/stmicro/stmmac/stmmac_main.c:7082:31: warning: symbol
> >'stmmac_xdp_metadata_ops' was not declared. Should it be static?
> Yes, you are right. It should be static. I will add correct it in v2. Thank you.

Thanks

2023-04-12 01:34:32

by Song, Yoong Siang

[permalink] [raw]
Subject: RE: [PATCH net-next 3/4] net: stmmac: add Rx HWTS metadata to XDP receive pkt

On Tuesday, April 11, 2023 12:25 AM, Stanislav Fomichev <[email protected]> wrote:
>On 04/10, Song Yoong Siang wrote:
>> Add receive hardware timestamp metadata support via kfunc to XDP
>> receive packets.
>>
>> Signed-off-by: Song Yoong Siang <[email protected]>
>> ---
>> drivers/net/ethernet/stmicro/stmmac/stmmac.h | 1 +
>> .../net/ethernet/stmicro/stmmac/stmmac_main.c | 24 +++++++++++++++++--
>> 2 files changed, 23 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac.h
>> b/drivers/net/ethernet/stmicro/stmmac/stmmac.h
>> index ac8ccf851708..760445275da8 100644
>> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac.h
>> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac.h
>> @@ -94,6 +94,7 @@ struct stmmac_rx_buffer {
>>
>> struct stmmac_xdp_buff {
>> struct xdp_buff xdp;
>> + ktime_t rx_hwts;
>> };
>>
>> struct stmmac_rx_queue {
>> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
>> b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
>> index f7bbdf04d20c..ca183fbfde85 100644
>> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
>> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
>> @@ -5307,6 +5307,8 @@ static int stmmac_rx(struct stmmac_priv *priv, int
>limit, u32 queue)
>> }
>> }
>>
>
>[..]
>
>> + stmmac_get_rx_hwtstamp(priv, p, np, &ctx.rx_hwts);
>
>Do we want to pay this cost for every packet?
>
>The preferred alternative is to store enough state in the stmmac_xdp_buff so we
>can get to this data from stmmac_xdp_rx_timestamp.
>
>I haven't read this code, but tentatively:
>- move priv, p, np into stmmac_xdp_buff, assign them here instead of
> calling stmmac_get_rx_hwtstamp
>- call stmmac_get_rx_hwtstamp from stmmac_xdp_rx_timestamp with the
> stored priv, p, np
>
>That would ensure that we won't waste the cycles pulling out the rx timestamp
>for every packet if the higher levels / users don't care.
>
>Would something like this work?

Hi Stanislav Fomichev,

Thanks for your comments.

Original stmmac_rx() function is already calling stmmac_get_rx_hwtstamp() for
every packet. This patch move the calling of stmmac_get_rx_hwtstamp() earlier
so that rx timestamp is available before running bpf_prog_run_xdp(). So, i
think no additional cost introduced here. Any other thoughts?

Furthermore, stmmac_get_rx_hwtstamp() will check whether hw timestamp is
enabled in driver and available in the descriptor before getting the hw timestamp.

>
>> +
>> if (!skb) {
>> unsigned int pre_len, sync_len;
>>
>> @@ -5315,7 +5317,7 @@ static int stmmac_rx(struct stmmac_priv *priv,
>> int limit, u32 queue)
>>
>> xdp_init_buff(&ctx.xdp, buf_sz, &rx_q->xdp_rxq);
>> xdp_prepare_buff(&ctx.xdp, page_address(buf->page),
>> - buf->page_offset, buf1_len, false);
>> + buf->page_offset, buf1_len, true);
>>
>> pre_len = ctx.xdp.data_end - ctx.xdp.data_hard_start -
>> buf->page_offset;
>> @@ -5411,7 +5413,7 @@ static int stmmac_rx(struct stmmac_priv *priv,
>> int limit, u32 queue)
>>
>> shhwtstamp = skb_hwtstamps(skb);
>> memset(shhwtstamp, 0, sizeof(struct skb_shared_hwtstamps));
>> - stmmac_get_rx_hwtstamp(priv, p, np, &shhwtstamp->hwtstamp);

Original stmmac_get_rx_hwtstamp() function is called here.

Thanks & Regards
Siang

>> + shhwtstamp->hwtstamp = ctx.rx_hwts;
>>
>> stmmac_rx_vlan(priv->dev, skb);
>> skb->protocol = eth_type_trans(skb, priv->dev); @@ -7071,6
>+7073,22
>> @@ void stmmac_fpe_handshake(struct stmmac_priv *priv, bool enable)
>> }
>> }
>>
>> +static int stmmac_xdp_rx_timestamp(const struct xdp_md *_ctx, u64
>> +*timestamp) {
>> + const struct stmmac_xdp_buff *ctx = (void *)_ctx;
>> +
>> + if (ctx->rx_hwts) {
>> + *timestamp = ctx->rx_hwts;
>> + return 0;
>> + }
>> +
>> + return -ENODATA;
>> +}
>> +
>> +const struct xdp_metadata_ops stmmac_xdp_metadata_ops = {
>> + .xmo_rx_timestamp = stmmac_xdp_rx_timestamp,
>> +};
>> +
>> /**
>> * stmmac_dvr_probe
>> * @device: device pointer
>> @@ -7178,6 +7196,8 @@ int stmmac_dvr_probe(struct device *device,
>>
>> ndev->netdev_ops = &stmmac_netdev_ops;
>>
>> + ndev->xdp_metadata_ops = &stmmac_xdp_metadata_ops;
>> +
>> ndev->hw_features = NETIF_F_SG | NETIF_F_IP_CSUM |
>NETIF_F_IPV6_CSUM |
>> NETIF_F_RXCSUM;
>> ndev->xdp_features = NETDEV_XDP_ACT_BASIC |
>NETDEV_XDP_ACT_REDIRECT
>> |
>> --
>> 2.34.1
>>

2023-04-12 04:06:36

by Song, Yoong Siang

[permalink] [raw]
Subject: RE: [PATCH net-next 3/4] net: stmmac: add Rx HWTS metadata to XDP receive pkt

On Wednesday, April 12, 2023 9:31 AM, Song Yoong Siang <[email protected]> wrote:
>On Tuesday, April 11, 2023 12:25 AM, Stanislav Fomichev <[email protected]>
>wrote:
>>On 04/10, Song Yoong Siang wrote:
>>> Add receive hardware timestamp metadata support via kfunc to XDP
>>> receive packets.
>>>
>>> Signed-off-by: Song Yoong Siang <[email protected]>
>>> ---
>>> drivers/net/ethernet/stmicro/stmmac/stmmac.h | 1 +
>>> .../net/ethernet/stmicro/stmmac/stmmac_main.c | 24
>>> +++++++++++++++++--
>>> 2 files changed, 23 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac.h
>>> b/drivers/net/ethernet/stmicro/stmmac/stmmac.h
>>> index ac8ccf851708..760445275da8 100644
>>> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac.h
>>> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac.h
>>> @@ -94,6 +94,7 @@ struct stmmac_rx_buffer {
>>>
>>> struct stmmac_xdp_buff {
>>> struct xdp_buff xdp;
>>> + ktime_t rx_hwts;
>>> };
>>>
>>> struct stmmac_rx_queue {
>>> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
>>> b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
>>> index f7bbdf04d20c..ca183fbfde85 100644
>>> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
>>> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
>>> @@ -5307,6 +5307,8 @@ static int stmmac_rx(struct stmmac_priv *priv,
>>> int
>>limit, u32 queue)
>>> }
>>> }
>>>
>>
>>[..]
>>
>>> + stmmac_get_rx_hwtstamp(priv, p, np, &ctx.rx_hwts);
>>
>>Do we want to pay this cost for every packet?
>>
>>The preferred alternative is to store enough state in the
>>stmmac_xdp_buff so we can get to this data from stmmac_xdp_rx_timestamp.
>>
>>I haven't read this code, but tentatively:
>>- move priv, p, np into stmmac_xdp_buff, assign them here instead of
>> calling stmmac_get_rx_hwtstamp
>>- call stmmac_get_rx_hwtstamp from stmmac_xdp_rx_timestamp with the
>> stored priv, p, np
>>
>>That would ensure that we won't waste the cycles pulling out the rx
>>timestamp for every packet if the higher levels / users don't care.
>>
>>Would something like this work?
>
>Hi Stanislav Fomichev,
>
>Thanks for your comments.
>
>Original stmmac_rx() function is already calling stmmac_get_rx_hwtstamp() for
>every packet. This patch move the calling of stmmac_get_rx_hwtstamp() earlier
>so that rx timestamp is available before running bpf_prog_run_xdp(). So, i think
>no additional cost introduced here. Any other thoughts?
>
>Furthermore, stmmac_get_rx_hwtstamp() will check whether hw timestamp is
>enabled in driver and available in the descriptor before getting the hw timestamp.
>
Hi Stanislav Fomichev,

I think twice. It might add some latency for certain verdict if the hw timestamp is
enabled but the user app dint need it. I will take your suggestion and try to pull
the timestamp per need basic. Will submit v3 soon.

Thanks & Regards
Siang
>>
>>> +
>>> if (!skb) {
>>> unsigned int pre_len, sync_len;
>>>
>>> @@ -5315,7 +5317,7 @@ static int stmmac_rx(struct stmmac_priv *priv,
>>> int limit, u32 queue)
>>>
>>> xdp_init_buff(&ctx.xdp, buf_sz, &rx_q->xdp_rxq);
>>> xdp_prepare_buff(&ctx.xdp, page_address(buf->page),
>>> - buf->page_offset, buf1_len, false);
>>> + buf->page_offset, buf1_len, true);
>>>
>>> pre_len = ctx.xdp.data_end - ctx.xdp.data_hard_start -
>>> buf->page_offset;
>>> @@ -5411,7 +5413,7 @@ static int stmmac_rx(struct stmmac_priv *priv,
>>> int limit, u32 queue)
>>>
>>> shhwtstamp = skb_hwtstamps(skb);
>>> memset(shhwtstamp, 0, sizeof(struct skb_shared_hwtstamps));
>>> - stmmac_get_rx_hwtstamp(priv, p, np, &shhwtstamp->hwtstamp);
>
>Original stmmac_get_rx_hwtstamp() function is called here.
>
>Thanks & Regards
>Siang
>
>>> + shhwtstamp->hwtstamp = ctx.rx_hwts;
>>>
>>> stmmac_rx_vlan(priv->dev, skb);
>>> skb->protocol = eth_type_trans(skb, priv->dev); @@ -7071,6
>>+7073,22
>>> @@ void stmmac_fpe_handshake(struct stmmac_priv *priv, bool enable)
>>> }
>>> }
>>>
>>> +static int stmmac_xdp_rx_timestamp(const struct xdp_md *_ctx, u64
>>> +*timestamp) {
>>> + const struct stmmac_xdp_buff *ctx = (void *)_ctx;
>>> +
>>> + if (ctx->rx_hwts) {
>>> + *timestamp = ctx->rx_hwts;
>>> + return 0;
>>> + }
>>> +
>>> + return -ENODATA;
>>> +}
>>> +
>>> +const struct xdp_metadata_ops stmmac_xdp_metadata_ops = {
>>> + .xmo_rx_timestamp = stmmac_xdp_rx_timestamp,
>>> +};
>>> +
>>> /**
>>> * stmmac_dvr_probe
>>> * @device: device pointer
>>> @@ -7178,6 +7196,8 @@ int stmmac_dvr_probe(struct device *device,
>>>
>>> ndev->netdev_ops = &stmmac_netdev_ops;
>>>
>>> + ndev->xdp_metadata_ops = &stmmac_xdp_metadata_ops;
>>> +
>>> ndev->hw_features = NETIF_F_SG | NETIF_F_IP_CSUM |
>>NETIF_F_IPV6_CSUM |
>>> NETIF_F_RXCSUM;
>>> ndev->xdp_features = NETDEV_XDP_ACT_BASIC |
>>NETDEV_XDP_ACT_REDIRECT
>>> |
>>> --
>>> 2.34.1
>>>