[PATCH net-next v2 0/4] Add support to do threaded napi busy poll

[PATCH net-next v2 0/4] Add support to do threaded napi busy poll

[Samiullah Khawaja]

Extend the already existing support of threaded napi poll to do continuous
busy polling.

This is used for doing continuous polling of napi to fetch descriptors from
backing RX/TX queues for low latency applications. Allow enabling of threaded
busypoll using netlink so this can be enabled on a set of dedicated napis for
low latency applications.

It allows enabling NAPI busy poll for any userspace application
indepdendent of userspace API being used for packet and event processing
(epoll, io_uring, raw socket APIs). Once enabled user can fetch the PID
of the kthread doing NAPI polling and set affinity, priority and
scheduler for it depending on the low-latency requirements.

Currently threaded napi is only enabled at device level using sysfs. Add
support to enable/disable threaded mode for a napi individually. This can be
done using the netlink interface. Extend `napi-set` op in netlink spec that
allows setting the `threaded` attribute of a napi.

Extend the threaded attribute in napi struct to add an option to enable
continuous busy polling. Extend the netlink and sysfs interface to allow
enabled/disabling threaded busypolling at device or individual napi level.

We use this for our AF_XDP based hard low-latency usecase using onload
stack (https://github.com/Xilinx-CNS/onload) that runs in userspace. Our
usecase is a fixed frequency RPC style traffic with fixed
request/response size. We simulated this using neper by only starting
next transaction when last one has completed. The experiment results are
listed below,

Setup:

- Running on Google C3 VMs with idpf driver with following configurations.
- IRQ affinity and coalascing is common for both experiments.
- There is only 1 RX/TX queue configured.
- First experiment enables busy poll using sysctl for both epoll and
  socket APIs.
- Second experiment enables NAPI threaded busy poll for the full device
  using sysctl.

Non threaded NAPI busy poll enabled using sysctl.
```
echo 400 | sudo tee /proc/sys/net/core/busy_poll
echo 400 | sudo tee /proc/sys/net/core/busy_read
echo 2 | sudo tee /sys/class/net/eth0/napi_defer_hard_irqs
echo 15000  | sudo tee /sys/class/net/eth0/gro_flush_timeout
```

Results using following command,
```
sudo EF_NO_FAIL=0 EF_POLL_USEC=100000 taskset -c 3-10 onload -v \
		--profile=latency ./neper/tcp_rr -Q 200 -R 400 -T 1 -F 50 \
		-p 50,90,99,999 -H <IP> -l 10

...
...

num_transactions=2835
latency_min=0.000018976
latency_max=0.049642100
latency_mean=0.003243618
latency_stddev=0.010636847
latency_p50=0.000025270
latency_p90=0.005406710
latency_p99=0.049807350
latency_p99.9=0.049807350
```

Results with napi threaded busy poll using following command,
```
sudo EF_NO_FAIL=0 EF_POLL_USEC=100000 taskset -c 3-10 onload -v \
                --profile=latency ./neper/tcp_rr -Q 200 -R 400 -T 1 -F 50 \
                -p 50,90,99,999 -H <IP> -l 10

...
...

num_transactions=460163
latency_min=0.000015707
latency_max=0.200182942
latency_mean=0.000019453
latency_stddev=0.000720727
latency_p50=0.000016950
latency_p90=0.000017270
latency_p99=0.000018710
latency_p99.9=0.000020150
```

Here with NAPI threaded busy poll in a separate core, we are able to
consistently poll the NAPI to keep latency to absolute minimum. And also
we are able to do this without any major changes to the onload stack and
threading model.

v2:
 - Add documentation in napi.rst.
 - Provide experiment data and usecase details.
 - Update busy_poller selftest to include napi threaded poll testcase.
 - Define threaded mode enum in netlink interface.
 - Included NAPI threaded state in napi config to save/restore.

Samiullah Khawaja (4):
  Add support to set napi threaded for individual napi
  net: Create separate gro_flush helper function
  Extend napi threaded polling to allow kthread based busy polling
  selftests: Add napi threaded busy poll test in `busy_poller`

 Documentation/ABI/testing/sysfs-class-net     |   3 +-
 Documentation/netlink/specs/netdev.yaml       |  14 ++
 Documentation/networking/napi.rst             |  80 ++++++++++-
 .../net/ethernet/atheros/atl1c/atl1c_main.c   |   2 +-
 include/linux/netdevice.h                     |  24 +++-
 include/uapi/linux/netdev.h                   |   7 +
 net/core/dev.c                                | 127 ++++++++++++++----
 net/core/net-sysfs.c                          |   2 +-
 net/core/netdev-genl-gen.c                    |   5 +-
 net/core/netdev-genl.c                        |   9 ++
 tools/include/uapi/linux/netdev.h             |   7 +
 tools/testing/selftests/net/busy_poll_test.sh |  25 +++-
 tools/testing/selftests/net/busy_poller.c     |  14 +-
 13 files changed, 282 insertions(+), 37 deletions(-)

-- 
2.48.1.262.g85cc9f2d1e-goog

[PATCH net-next v2 1/4] Add support to set napi threaded for individual napi

[Samiullah Khawaja]

A net device has a threaded sysctl that can be used to enable threaded
napi polling on all of the NAPI contexts under that device. Allow
enabling threaded napi polling at individual napi level using netlink.

Extend the netlink operation `napi-set` and allow setting the threaded
attribute of a NAPI. This will enable the threaded polling on a napi
context.

Tested using following command in qemu/virtio-net:
./tools/net/ynl/cli.py --spec Documentation/netlink/specs/netdev.yaml \
  --do napi-set       --json '{"id": 66, "threaded": 1}'

Signed-off-by: Samiullah Khawaja <skhawaja@google.com>
---
 Documentation/netlink/specs/netdev.yaml | 10 ++++++++
 Documentation/networking/napi.rst       | 13 ++++++++++-
 include/linux/netdevice.h               | 10 ++++++++
 include/uapi/linux/netdev.h             |  1 +
 net/core/dev.c                          | 31 +++++++++++++++++++++++++
 net/core/netdev-genl-gen.c              |  5 ++--
 net/core/netdev-genl.c                  |  9 +++++++
 tools/include/uapi/linux/netdev.h       |  1 +
 8 files changed, 77 insertions(+), 3 deletions(-)

diff --git a/Documentation/netlink/specs/netdev.yaml b/Documentation/netlink/specs/netdev.yaml
index cbb544bd6c84..785240d60df6 100644
--- a/Documentation/netlink/specs/netdev.yaml
+++ b/Documentation/netlink/specs/netdev.yaml
@@ -268,6 +268,14 @@ attribute-sets:
         doc: The timeout, in nanoseconds, of how long to suspend irq
              processing, if event polling finds events
         type: uint
+      -
+        name: threaded
+        doc: Whether the napi is configured to operate in threaded polling
+             mode. If this is set to `1` then the NAPI context operates
+             in threaded polling mode.
+        type: u32
+        checks:
+          max: 1
   -
     name: queue
     attributes:
@@ -659,6 +667,7 @@ operations:
             - defer-hard-irqs
             - gro-flush-timeout
             - irq-suspend-timeout
+            - threaded
       dump:
         request:
           attributes:
@@ -711,6 +720,7 @@ operations:
             - defer-hard-irqs
             - gro-flush-timeout
             - irq-suspend-timeout
+            - threaded
 
 kernel-family:
   headers: [ "linux/list.h"]
diff --git a/Documentation/networking/napi.rst b/Documentation/networking/napi.rst
index 6083210ab2a4..41926e7a3dd4 100644
--- a/Documentation/networking/napi.rst
+++ b/Documentation/networking/napi.rst
@@ -413,7 +413,18 @@ dependent). The NAPI instance IDs will be assigned in the opposite
 order than the process IDs of the kernel threads.
 
 Threaded NAPI is controlled by writing 0/1 to the ``threaded`` file in
-netdev's sysfs directory.
+netdev's sysfs directory. It can also be enabled for a specific napi using
+netlink interface.
+
+For example, using the script:
+
+.. code-block:: bash
+
+  $ kernel-source/tools/net/ynl/pyynl/cli.py \
+            --spec Documentation/netlink/specs/netdev.yaml \
+            --do napi-set \
+            --json='{"id": 66,
+                     "threaded": 1}'
 
 .. rubric:: Footnotes
 
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 8da4c61f97b9..6afba24b18d1 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -352,6 +352,7 @@ struct napi_config {
 	u64 gro_flush_timeout;
 	u64 irq_suspend_timeout;
 	u32 defer_hard_irqs;
+	bool threaded;
 	unsigned int napi_id;
 };
 
@@ -572,6 +573,15 @@ static inline bool napi_complete(struct napi_struct *n)
 
 int dev_set_threaded(struct net_device *dev, bool threaded);
 
+/*
+ * napi_set_threaded - set napi threaded state
+ * @napi: NAPI context
+ * @threaded: whether this napi does threaded polling
+ *
+ * Return 0 on success and negative errno on failure.
+ */
+int napi_set_threaded(struct napi_struct *napi, bool threaded);
+
 void napi_disable(struct napi_struct *n);
 void napi_disable_locked(struct napi_struct *n);
 
diff --git a/include/uapi/linux/netdev.h b/include/uapi/linux/netdev.h
index e4be227d3ad6..829648b2ef65 100644
--- a/include/uapi/linux/netdev.h
+++ b/include/uapi/linux/netdev.h
@@ -125,6 +125,7 @@ enum {
 	NETDEV_A_NAPI_DEFER_HARD_IRQS,
 	NETDEV_A_NAPI_GRO_FLUSH_TIMEOUT,
 	NETDEV_A_NAPI_IRQ_SUSPEND_TIMEOUT,
+	NETDEV_A_NAPI_THREADED,
 
 	__NETDEV_A_NAPI_MAX,
 	NETDEV_A_NAPI_MAX = (__NETDEV_A_NAPI_MAX - 1)
diff --git a/net/core/dev.c b/net/core/dev.c
index afa2282f2604..3885f3095873 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -6787,6 +6787,30 @@ static void init_gro_hash(struct napi_struct *napi)
 	napi->gro_bitmask = 0;
 }
 
+int napi_set_threaded(struct napi_struct *napi, bool threaded)
+{
+	if (napi->dev->threaded)
+		return -EINVAL;
+
+	if (threaded) {
+		if (!napi->thread) {
+			int err = napi_kthread_create(napi);
+
+			if (err)
+				return err;
+		}
+	}
+
+	if (napi->config)
+		napi->config->threaded = threaded;
+
+	/* Make sure kthread is created before THREADED bit is set. */
+	smp_mb__before_atomic();
+	assign_bit(NAPI_STATE_THREADED, &napi->state, threaded);
+
+	return 0;
+}
+
 int dev_set_threaded(struct net_device *dev, bool threaded)
 {
 	struct napi_struct *napi;
@@ -6798,6 +6822,11 @@ int dev_set_threaded(struct net_device *dev, bool threaded)
 		return 0;
 
 	if (threaded) {
+		/* Check if threaded is set at napi level already */
+		list_for_each_entry(napi, &dev->napi_list, dev_list)
+			if (test_bit(NAPI_STATE_THREADED, &napi->state))
+				return -EINVAL;
+
 		list_for_each_entry(napi, &dev->napi_list, dev_list) {
 			if (!napi->thread) {
 				err = napi_kthread_create(napi);
@@ -6880,6 +6909,8 @@ static void napi_restore_config(struct napi_struct *n)
 		napi_hash_add(n);
 		n->config->napi_id = n->napi_id;
 	}
+
+	napi_set_threaded(n, n->config->threaded);
 }
 
 static void napi_save_config(struct napi_struct *n)
diff --git a/net/core/netdev-genl-gen.c b/net/core/netdev-genl-gen.c
index 996ac6a449eb..a1f80e687f53 100644
--- a/net/core/netdev-genl-gen.c
+++ b/net/core/netdev-genl-gen.c
@@ -92,11 +92,12 @@ static const struct nla_policy netdev_bind_rx_nl_policy[NETDEV_A_DMABUF_FD + 1]
 };
 
 /* NETDEV_CMD_NAPI_SET - do */
-static const struct nla_policy netdev_napi_set_nl_policy[NETDEV_A_NAPI_IRQ_SUSPEND_TIMEOUT + 1] = {
+static const struct nla_policy netdev_napi_set_nl_policy[NETDEV_A_NAPI_THREADED + 1] = {
 	[NETDEV_A_NAPI_ID] = { .type = NLA_U32, },
 	[NETDEV_A_NAPI_DEFER_HARD_IRQS] = NLA_POLICY_FULL_RANGE(NLA_U32, &netdev_a_napi_defer_hard_irqs_range),
 	[NETDEV_A_NAPI_GRO_FLUSH_TIMEOUT] = { .type = NLA_UINT, },
 	[NETDEV_A_NAPI_IRQ_SUSPEND_TIMEOUT] = { .type = NLA_UINT, },
+	[NETDEV_A_NAPI_THREADED] = NLA_POLICY_MAX(NLA_U32, 1),
 };
 
 /* Ops table for netdev */
@@ -187,7 +188,7 @@ static const struct genl_split_ops netdev_nl_ops[] = {
 		.cmd		= NETDEV_CMD_NAPI_SET,
 		.doit		= netdev_nl_napi_set_doit,
 		.policy		= netdev_napi_set_nl_policy,
-		.maxattr	= NETDEV_A_NAPI_IRQ_SUSPEND_TIMEOUT,
+		.maxattr	= NETDEV_A_NAPI_THREADED,
 		.flags		= GENL_ADMIN_PERM | GENL_CMD_CAP_DO,
 	},
 };
diff --git a/net/core/netdev-genl.c b/net/core/netdev-genl.c
index 715f85c6b62e..208c3dd768ec 100644
--- a/net/core/netdev-genl.c
+++ b/net/core/netdev-genl.c
@@ -183,6 +183,9 @@ netdev_nl_napi_fill_one(struct sk_buff *rsp, struct napi_struct *napi,
 	if (napi->irq >= 0 && nla_put_u32(rsp, NETDEV_A_NAPI_IRQ, napi->irq))
 		goto nla_put_failure;
 
+	if (nla_put_u32(rsp, NETDEV_A_NAPI_THREADED, !!napi->thread))
+		goto nla_put_failure;
+
 	if (napi->thread) {
 		pid = task_pid_nr(napi->thread);
 		if (nla_put_u32(rsp, NETDEV_A_NAPI_PID, pid))
@@ -321,8 +324,14 @@ netdev_nl_napi_set_config(struct napi_struct *napi, struct genl_info *info)
 {
 	u64 irq_suspend_timeout = 0;
 	u64 gro_flush_timeout = 0;
+	u32 threaded = 0;
 	u32 defer = 0;
 
+	if (info->attrs[NETDEV_A_NAPI_THREADED]) {
+		threaded = nla_get_u32(info->attrs[NETDEV_A_NAPI_THREADED]);
+		napi_set_threaded(napi, !!threaded);
+	}
+
 	if (info->attrs[NETDEV_A_NAPI_DEFER_HARD_IRQS]) {
 		defer = nla_get_u32(info->attrs[NETDEV_A_NAPI_DEFER_HARD_IRQS]);
 		napi_set_defer_hard_irqs(napi, defer);
diff --git a/tools/include/uapi/linux/netdev.h b/tools/include/uapi/linux/netdev.h
index e4be227d3ad6..829648b2ef65 100644
--- a/tools/include/uapi/linux/netdev.h
+++ b/tools/include/uapi/linux/netdev.h
@@ -125,6 +125,7 @@ enum {
 	NETDEV_A_NAPI_DEFER_HARD_IRQS,
 	NETDEV_A_NAPI_GRO_FLUSH_TIMEOUT,
 	NETDEV_A_NAPI_IRQ_SUSPEND_TIMEOUT,
+	NETDEV_A_NAPI_THREADED,
 
 	__NETDEV_A_NAPI_MAX,
 	NETDEV_A_NAPI_MAX = (__NETDEV_A_NAPI_MAX - 1)
-- 
2.48.1.262.g85cc9f2d1e-goog

[PATCH net-next v2 2/4] net: Create separate gro_flush helper function

[Samiullah Khawaja]

Move multiple copies of same code snippet doing `gro_flush` and
`gro_normal_list` into a separate helper function.

Signed-off-by: Samiullah Khawaja <skhawaja@google.com>
---
 net/core/dev.c | 28 +++++++++++++---------------
 1 file changed, 13 insertions(+), 15 deletions(-)

diff --git a/net/core/dev.c b/net/core/dev.c
index 3885f3095873..484947ad5410 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -6484,6 +6484,17 @@ static void skb_defer_free_flush(struct softnet_data *sd)
 	}
 }
 
+static void __napi_gro_flush_helper(struct napi_struct *napi)
+{
+	if (napi->gro_bitmask) {
+		/* flush too old packets
+		 * If HZ < 1000, flush all packets.
+		 */
+		napi_gro_flush(napi, HZ >= 1000);
+	}
+	gro_normal_list(napi);
+}
+
 #if defined(CONFIG_NET_RX_BUSY_POLL)
 
 static void __busy_poll_stop(struct napi_struct *napi, bool skip_schedule)
@@ -6494,14 +6505,8 @@ static void __busy_poll_stop(struct napi_struct *napi, bool skip_schedule)
 		return;
 	}
 
-	if (napi->gro_bitmask) {
-		/* flush too old packets
-		 * If HZ < 1000, flush all packets.
-		 */
-		napi_gro_flush(napi, HZ >= 1000);
-	}
+	__napi_gro_flush_helper(napi);
 
-	gro_normal_list(napi);
 	clear_bit(NAPI_STATE_SCHED, &napi->state);
 }
 
@@ -7170,14 +7175,7 @@ static int __napi_poll(struct napi_struct *n, bool *repoll)
 		return work;
 	}
 
-	if (n->gro_bitmask) {
-		/* flush too old packets
-		 * If HZ < 1000, flush all packets.
-		 */
-		napi_gro_flush(n, HZ >= 1000);
-	}
-
-	gro_normal_list(n);
+	__napi_gro_flush_helper(n);
 
 	/* Some drivers may have called napi_schedule
 	 * prior to exhausting their budget.
-- 
2.48.1.262.g85cc9f2d1e-goog

[PATCH net-next v2 3/4] Extend napi threaded polling to allow kthread based busy polling

[Samiullah Khawaja]

Add a new state to napi state enum:

- STATE_THREADED_BUSY_POLL
  Threaded busy poll is enabled/running for this napi.

Following changes are introduced in the napi scheduling and state logic:

- When threaded busy poll is enabled through sysfs it also enables
  NAPI_STATE_THREADED so a kthread is created per napi. It also sets
  NAPI_STATE_THREADED_BUSY_POLL bit on each napi to indicate that we are
  supposed to busy poll for each napi.

- When napi is scheduled with STATE_SCHED_THREADED and associated
  kthread is woken up, the kthread owns the context. If
  NAPI_STATE_THREADED_BUSY_POLL and NAPI_SCHED_THREADED both are set
  then it means that we can busy poll.

- To keep busy polling and to avoid scheduling of the interrupts, the
  napi_complete_done returns false when both SCHED_THREADED and
  THREADED_BUSY_POLL flags are set. Also napi_complete_done returns
  early to avoid the STATE_SCHED_THREADED being unset.

- If at any point STATE_THREADED_BUSY_POLL is unset, the
  napi_complete_done will run and unset the SCHED_THREADED bit also.
  This will make the associated kthread go to sleep as per existing
  logic.

Signed-off-by: Samiullah Khawaja <skhawaja@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
---
 Documentation/ABI/testing/sysfs-class-net     |  3 +-
 Documentation/netlink/specs/netdev.yaml       | 12 ++--
 Documentation/networking/napi.rst             | 67 ++++++++++++++++-
 .../net/ethernet/atheros/atl1c/atl1c_main.c   |  2 +-
 include/linux/netdevice.h                     | 20 ++++--
 include/uapi/linux/netdev.h                   |  6 ++
 net/core/dev.c                                | 72 ++++++++++++++++---
 net/core/net-sysfs.c                          |  2 +-
 net/core/netdev-genl-gen.c                    |  2 +-
 net/core/netdev-genl.c                        |  2 +-
 tools/include/uapi/linux/netdev.h             |  6 ++
 11 files changed, 168 insertions(+), 26 deletions(-)

diff --git a/Documentation/ABI/testing/sysfs-class-net b/Documentation/ABI/testing/sysfs-class-net
index ebf21beba846..15d7d36a8294 100644
--- a/Documentation/ABI/testing/sysfs-class-net
+++ b/Documentation/ABI/testing/sysfs-class-net
@@ -343,7 +343,7 @@ Date:		Jan 2021
 KernelVersion:	5.12
 Contact:	netdev@vger.kernel.org
 Description:
-		Boolean value to control the threaded mode per device. User could
+		Integer value to control the threaded mode per device. User could
 		set this value to enable/disable threaded mode for all napi
 		belonging to this device, without the need to do device up/down.
 
@@ -351,4 +351,5 @@ Description:
 		== ==================================
 		0  threaded mode disabled for this dev
 		1  threaded mode enabled for this dev
+		2  threaded mode enabled, and busy polling enabled.
 		== ==================================
diff --git a/Documentation/netlink/specs/netdev.yaml b/Documentation/netlink/specs/netdev.yaml
index 785240d60df6..db3bf1eb9a63 100644
--- a/Documentation/netlink/specs/netdev.yaml
+++ b/Documentation/netlink/specs/netdev.yaml
@@ -78,6 +78,10 @@ definitions:
     name: qstats-scope
     type: flags
     entries: [ queue ]
+  -
+    name: napi-threaded
+    type: enum
+    entries: [ disable, enable, busy-poll-enable ]
 
 attribute-sets:
   -
@@ -271,11 +275,11 @@ attribute-sets:
       -
         name: threaded
         doc: Whether the napi is configured to operate in threaded polling
-             mode. If this is set to `1` then the NAPI context operates
-             in threaded polling mode.
+             mode. If this is set to `enable` then the NAPI context operates
+             in threaded polling mode. If this is set to `busy-poll-enable`
+             then the NAPI kthread also does busypolling.
         type: u32
-        checks:
-          max: 1
+        enum: napi-threaded
   -
     name: queue
     attributes:
diff --git a/Documentation/networking/napi.rst b/Documentation/networking/napi.rst
index 41926e7a3dd4..edecc21f0bca 100644
--- a/Documentation/networking/napi.rst
+++ b/Documentation/networking/napi.rst
@@ -232,7 +232,9 @@ are not well known).
 Busy polling is enabled by either setting ``SO_BUSY_POLL`` on
 selected sockets or using the global ``net.core.busy_poll`` and
 ``net.core.busy_read`` sysctls. An io_uring API for NAPI busy polling
-also exists.
+also exists. Threaded polling of NAPI also has a mode to busy poll for
+packets (:ref:`threaded busy polling<threaded_busy_poll>`) using the same
+thread that is used for NAPI processing.
 
 epoll-based busy polling
 ------------------------
@@ -395,6 +397,69 @@ Therefore, setting ``gro_flush_timeout`` and ``napi_defer_hard_irqs`` is
 the recommended usage, because otherwise setting ``irq-suspend-timeout``
 might not have any discernible effect.
 
+.. _threaded_busy_poll:
+
+Threaded NAPI busy polling
+--------------------------
+
+Threaded napi allows processing of packets from each NAPI in a kthread in
+kernel. Threaded napi busy polling extends this and adds support to do
+continuous busy polling of this napi. This can be used to enable busy polling
+independent of userspace application or the API (epoll, io_uring, raw sockets)
+being used in userspace to process the packets.
+
+It can be enabled for each NAPI using netlink interface or at device level using
+the threaded NAPI sysctl.
+
+For example, using following script:
+
+.. code-block:: bash
+
+  $ kernel-source/tools/net/ynl/pyynl/cli.py \
+            --spec Documentation/netlink/specs/netdev.yaml \
+            --do napi-set \
+            --json='{"id": 66,
+                     "threaded": "busy-poll-enable"}'
+
+
+Enabling it for each NAPI allows finer control to enable busy pollling for
+only a set of NIC queues which will get traffic with low latency requirements.
+
+Depending on application requirement, user might want to set affinity of the
+kthread that is busy polling each NAPI. User might also want to set priority
+and the scheduler of the thread depending on the latency requirements.
+
+For a hard low-latency application, user might want to dedicate the full core
+for the NAPI polling so the NIC queue descriptors are picked up from the queue
+as soon as they appear. For more relaxed low-latency requirement, user might
+want to share the core with other threads.
+
+Once threaded busy polling is enabled for a NAPI, PID of the kthread can be
+fetched using netlink interface so the affinity, priority and scheduler
+configuration can be done.
+
+For example, following script can be used to fetch the pid:
+
+.. code-block:: bash
+
+  $ kernel-source/tools/net/ynl/pyynl/cli.py \
+            --spec Documentation/netlink/specs/netdev.yaml \
+            --do napi-get \
+            --json='{"id": 66}'
+
+This will output something like following, the pid `258` is the PID of the
+kthread that is polling this NAPI.
+
+.. code-block:: bash
+
+  $ {'defer-hard-irqs': 0,
+     'gro-flush-timeout': 0,
+     'id': 66,
+     'ifindex': 2,
+     'irq-suspend-timeout': 0,
+     'pid': 258,
+     'threaded': 'enable'}
+
 .. _threaded:
 
 Threaded NAPI
diff --git a/drivers/net/ethernet/atheros/atl1c/atl1c_main.c b/drivers/net/ethernet/atheros/atl1c/atl1c_main.c
index c571614b1d50..513328476770 100644
--- a/drivers/net/ethernet/atheros/atl1c/atl1c_main.c
+++ b/drivers/net/ethernet/atheros/atl1c/atl1c_main.c
@@ -2688,7 +2688,7 @@ static int atl1c_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 	adapter->mii.mdio_write = atl1c_mdio_write;
 	adapter->mii.phy_id_mask = 0x1f;
 	adapter->mii.reg_num_mask = MDIO_CTRL_REG_MASK;
-	dev_set_threaded(netdev, true);
+	dev_set_threaded(netdev, NETDEV_NAPI_THREADED_ENABLE);
 	for (i = 0; i < adapter->rx_queue_count; ++i)
 		netif_napi_add(netdev, &adapter->rrd_ring[i].napi,
 			       atl1c_clean_rx);
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 6afba24b18d1..9d6bb0d719b3 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -352,7 +352,7 @@ struct napi_config {
 	u64 gro_flush_timeout;
 	u64 irq_suspend_timeout;
 	u32 defer_hard_irqs;
-	bool threaded;
+	u8 threaded;
 	unsigned int napi_id;
 };
 
@@ -410,6 +410,8 @@ enum {
 	NAPI_STATE_PREFER_BUSY_POLL,	/* prefer busy-polling over softirq processing*/
 	NAPI_STATE_THREADED,		/* The poll is performed inside its own thread*/
 	NAPI_STATE_SCHED_THREADED,	/* Napi is currently scheduled in threaded mode */
+	NAPI_STATE_THREADED_BUSY_POLL,	/* The threaded napi poller will busy poll */
+	NAPI_STATE_SCHED_THREADED_BUSY_POLL,  /* The threaded napi poller is busy polling */
 };
 
 enum {
@@ -423,8 +425,14 @@ enum {
 	NAPIF_STATE_PREFER_BUSY_POLL	= BIT(NAPI_STATE_PREFER_BUSY_POLL),
 	NAPIF_STATE_THREADED		= BIT(NAPI_STATE_THREADED),
 	NAPIF_STATE_SCHED_THREADED	= BIT(NAPI_STATE_SCHED_THREADED),
+	NAPIF_STATE_THREADED_BUSY_POLL	= BIT(NAPI_STATE_THREADED_BUSY_POLL),
+	NAPIF_STATE_SCHED_THREADED_BUSY_POLL
+				= BIT(NAPI_STATE_SCHED_THREADED_BUSY_POLL),
 };
 
+#define NAPIF_STATE_THREADED_BUSY_POLL_MASK \
+	(NAPIF_STATE_THREADED | NAPIF_STATE_THREADED_BUSY_POLL)
+
 enum gro_result {
 	GRO_MERGED,
 	GRO_MERGED_FREE,
@@ -571,16 +579,18 @@ static inline bool napi_complete(struct napi_struct *n)
 	return napi_complete_done(n, 0);
 }
 
-int dev_set_threaded(struct net_device *dev, bool threaded);
+int dev_set_threaded(struct net_device *dev,
+		     enum netdev_napi_threaded threaded);
 
 /*
  * napi_set_threaded - set napi threaded state
  * @napi: NAPI context
- * @threaded: whether this napi does threaded polling
+ * @threaded: threading mode
  *
  * Return 0 on success and negative errno on failure.
  */
-int napi_set_threaded(struct napi_struct *napi, bool threaded);
+int napi_set_threaded(struct napi_struct *napi,
+		      enum netdev_napi_threaded threaded);
 
 void napi_disable(struct napi_struct *n);
 void napi_disable_locked(struct napi_struct *n);
@@ -2404,7 +2414,7 @@ struct net_device {
 	struct sfp_bus		*sfp_bus;
 	struct lock_class_key	*qdisc_tx_busylock;
 	bool			proto_down;
-	bool			threaded;
+	u8			threaded;
 
 	/* priv_flags_slow, ungrouped to save space */
 	unsigned long		see_all_hwtstamp_requests:1;
diff --git a/include/uapi/linux/netdev.h b/include/uapi/linux/netdev.h
index 829648b2ef65..c2a9dbb361f6 100644
--- a/include/uapi/linux/netdev.h
+++ b/include/uapi/linux/netdev.h
@@ -74,6 +74,12 @@ enum netdev_qstats_scope {
 	NETDEV_QSTATS_SCOPE_QUEUE = 1,
 };
 
+enum netdev_napi_threaded {
+	NETDEV_NAPI_THREADED_DISABLE,
+	NETDEV_NAPI_THREADED_ENABLE,
+	NETDEV_NAPI_THREADED_BUSY_POLL_ENABLE,
+};
+
 enum {
 	NETDEV_A_DEV_IFINDEX = 1,
 	NETDEV_A_DEV_PAD,
diff --git a/net/core/dev.c b/net/core/dev.c
index 484947ad5410..8a5fde81f0b8 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -78,6 +78,7 @@
 #include <linux/slab.h>
 #include <linux/sched.h>
 #include <linux/sched/isolation.h>
+#include <linux/sched/types.h>
 #include <linux/sched/mm.h>
 #include <linux/smpboot.h>
 #include <linux/mutex.h>
@@ -6403,7 +6404,8 @@ bool napi_complete_done(struct napi_struct *n, int work_done)
 	 *    the guarantee we will be called later.
 	 */
 	if (unlikely(n->state & (NAPIF_STATE_NPSVC |
-				 NAPIF_STATE_IN_BUSY_POLL)))
+				 NAPIF_STATE_IN_BUSY_POLL |
+				 NAPIF_STATE_SCHED_THREADED_BUSY_POLL)))
 		return false;
 
 	if (work_done) {
@@ -6792,8 +6794,10 @@ static void init_gro_hash(struct napi_struct *napi)
 	napi->gro_bitmask = 0;
 }
 
-int napi_set_threaded(struct napi_struct *napi, bool threaded)
+int napi_set_threaded(struct napi_struct *napi,
+		      enum netdev_napi_threaded threaded)
 {
+	unsigned long val;
 	if (napi->dev->threaded)
 		return -EINVAL;
 
@@ -6811,14 +6815,20 @@ int napi_set_threaded(struct napi_struct *napi, bool threaded)
 
 	/* Make sure kthread is created before THREADED bit is set. */
 	smp_mb__before_atomic();
-	assign_bit(NAPI_STATE_THREADED, &napi->state, threaded);
+	val = 0;
+	if (threaded == NETDEV_NAPI_THREADED_BUSY_POLL_ENABLE)
+		val |= NAPIF_STATE_THREADED_BUSY_POLL;
+	if (threaded)
+		val |= NAPIF_STATE_THREADED;
+	set_mask_bits(&napi->state, NAPIF_STATE_THREADED_BUSY_POLL_MASK, val);
 
 	return 0;
 }
 
-int dev_set_threaded(struct net_device *dev, bool threaded)
+int dev_set_threaded(struct net_device *dev, enum netdev_napi_threaded threaded)
 {
 	struct napi_struct *napi;
+	unsigned long val;
 	int err = 0;
 
 	netdev_assert_locked_or_invisible(dev);
@@ -6826,17 +6836,22 @@ int dev_set_threaded(struct net_device *dev, bool threaded)
 	if (dev->threaded == threaded)
 		return 0;
 
+	val = 0;
 	if (threaded) {
 		/* Check if threaded is set at napi level already */
 		list_for_each_entry(napi, &dev->napi_list, dev_list)
 			if (test_bit(NAPI_STATE_THREADED, &napi->state))
 				return -EINVAL;
 
+		val |= NAPIF_STATE_THREADED;
+		if (threaded == NETDEV_NAPI_THREADED_BUSY_POLL_ENABLE)
+			val |= NAPIF_STATE_THREADED_BUSY_POLL;
+
 		list_for_each_entry(napi, &dev->napi_list, dev_list) {
 			if (!napi->thread) {
 				err = napi_kthread_create(napi);
 				if (err) {
-					threaded = false;
+					threaded = NETDEV_NAPI_THREADED_DISABLE;
 					break;
 				}
 			}
@@ -6855,9 +6870,13 @@ int dev_set_threaded(struct net_device *dev, bool threaded)
 	 * polled. In this case, the switch between threaded mode and
 	 * softirq mode will happen in the next round of napi_schedule().
 	 * This should not cause hiccups/stalls to the live traffic.
+	 *
+	 * Switch to busy_poll threaded napi will occur after the threaded
+	 * napi is scheduled.
 	 */
 	list_for_each_entry(napi, &dev->napi_list, dev_list)
-		assign_bit(NAPI_STATE_THREADED, &napi->state, threaded);
+		set_mask_bits(&napi->state,
+			      NAPIF_STATE_THREADED_BUSY_POLL_MASK, val);
 
 	return err;
 }
@@ -7235,7 +7254,7 @@ static int napi_thread_wait(struct napi_struct *napi)
 	return -1;
 }
 
-static void napi_threaded_poll_loop(struct napi_struct *napi)
+static void napi_threaded_poll_loop(struct napi_struct *napi, bool busy_poll)
 {
 	struct bpf_net_context __bpf_net_ctx, *bpf_net_ctx;
 	struct softnet_data *sd;
@@ -7264,22 +7283,53 @@ static void napi_threaded_poll_loop(struct napi_struct *napi)
 		}
 		skb_defer_free_flush(sd);
 		bpf_net_ctx_clear(bpf_net_ctx);
+
+		/* Push the skbs up the stack if busy polling. */
+		if (busy_poll)
+			__napi_gro_flush_helper(napi);
 		local_bh_enable();
 
-		if (!repoll)
+		/* If busy polling then do not break here because we need to
+		 * call cond_resched and rcu_softirq_qs_periodic to prevent
+		 * watchdog warnings.
+		 */
+		if (!repoll && !busy_poll)
 			break;
 
 		rcu_softirq_qs_periodic(last_qs);
 		cond_resched();
+
+		if (!repoll)
+			break;
 	}
 }
 
 static int napi_threaded_poll(void *data)
 {
 	struct napi_struct *napi = data;
+	bool busy_poll_sched;
+	unsigned long val;
+	bool busy_poll;
+
+	while (!napi_thread_wait(napi)) {
+		/* Once woken up, this means that we are scheduled as threaded
+		 * napi and this thread owns the napi context, if busy poll
+		 * state is set then we busy poll this napi.
+		 */
+		val = READ_ONCE(napi->state);
+		busy_poll = val & NAPIF_STATE_THREADED_BUSY_POLL;
+		busy_poll_sched = val & NAPIF_STATE_SCHED_THREADED_BUSY_POLL;
+
+		/* Do not busy poll if napi is disabled. */
+		if (unlikely(val & NAPIF_STATE_DISABLE))
+			busy_poll = false;
+
+		if (busy_poll != busy_poll_sched)
+			assign_bit(NAPI_STATE_SCHED_THREADED_BUSY_POLL,
+				   &napi->state, busy_poll);
 
-	while (!napi_thread_wait(napi))
-		napi_threaded_poll_loop(napi);
+		napi_threaded_poll_loop(napi, busy_poll);
+	}
 
 	return 0;
 }
@@ -12497,7 +12547,7 @@ static void run_backlog_napi(unsigned int cpu)
 {
 	struct softnet_data *sd = per_cpu_ptr(&softnet_data, cpu);
 
-	napi_threaded_poll_loop(&sd->backlog);
+	napi_threaded_poll_loop(&sd->backlog, false);
 }
 
 static void backlog_napi_setup(unsigned int cpu)
diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c
index 07cb99b114bd..beb496bcb633 100644
--- a/net/core/net-sysfs.c
+++ b/net/core/net-sysfs.c
@@ -657,7 +657,7 @@ static int modify_napi_threaded(struct net_device *dev, unsigned long val)
 	if (list_empty(&dev->napi_list))
 		return -EOPNOTSUPP;
 
-	if (val != 0 && val != 1)
+	if (val > NETDEV_NAPI_THREADED_BUSY_POLL_ENABLE)
 		return -EOPNOTSUPP;
 
 	ret = dev_set_threaded(dev, val);
diff --git a/net/core/netdev-genl-gen.c b/net/core/netdev-genl-gen.c
index a1f80e687f53..b572beba42e7 100644
--- a/net/core/netdev-genl-gen.c
+++ b/net/core/netdev-genl-gen.c
@@ -97,7 +97,7 @@ static const struct nla_policy netdev_napi_set_nl_policy[NETDEV_A_NAPI_THREADED
 	[NETDEV_A_NAPI_DEFER_HARD_IRQS] = NLA_POLICY_FULL_RANGE(NLA_U32, &netdev_a_napi_defer_hard_irqs_range),
 	[NETDEV_A_NAPI_GRO_FLUSH_TIMEOUT] = { .type = NLA_UINT, },
 	[NETDEV_A_NAPI_IRQ_SUSPEND_TIMEOUT] = { .type = NLA_UINT, },
-	[NETDEV_A_NAPI_THREADED] = NLA_POLICY_MAX(NLA_U32, 1),
+	[NETDEV_A_NAPI_THREADED] = NLA_POLICY_MAX(NLA_U32, 2),
 };
 
 /* Ops table for netdev */
diff --git a/net/core/netdev-genl.c b/net/core/netdev-genl.c
index 208c3dd768ec..7ae5f3ed0961 100644
--- a/net/core/netdev-genl.c
+++ b/net/core/netdev-genl.c
@@ -329,7 +329,7 @@ netdev_nl_napi_set_config(struct napi_struct *napi, struct genl_info *info)
 
 	if (info->attrs[NETDEV_A_NAPI_THREADED]) {
 		threaded = nla_get_u32(info->attrs[NETDEV_A_NAPI_THREADED]);
-		napi_set_threaded(napi, !!threaded);
+		napi_set_threaded(napi, threaded);
 	}
 
 	if (info->attrs[NETDEV_A_NAPI_DEFER_HARD_IRQS]) {
diff --git a/tools/include/uapi/linux/netdev.h b/tools/include/uapi/linux/netdev.h
index 829648b2ef65..c2a9dbb361f6 100644
--- a/tools/include/uapi/linux/netdev.h
+++ b/tools/include/uapi/linux/netdev.h
@@ -74,6 +74,12 @@ enum netdev_qstats_scope {
 	NETDEV_QSTATS_SCOPE_QUEUE = 1,
 };
 
+enum netdev_napi_threaded {
+	NETDEV_NAPI_THREADED_DISABLE,
+	NETDEV_NAPI_THREADED_ENABLE,
+	NETDEV_NAPI_THREADED_BUSY_POLL_ENABLE,
+};
+
 enum {
 	NETDEV_A_DEV_IFINDEX = 1,
 	NETDEV_A_DEV_PAD,
-- 
2.48.1.262.g85cc9f2d1e-goog

[PATCH net-next v2 4/4] selftests: Add napi threaded busy poll test in `busy_poller`

[Samiullah Khawaja]

Add testcase to run busy poll test with threaded napi busy poll enabled.

Signed-off-by: Samiullah Khawaja <skhawaja@google.com>
---
 tools/testing/selftests/net/busy_poll_test.sh | 25 ++++++++++++++++++-
 tools/testing/selftests/net/busy_poller.c     | 14 ++++++++---
 2 files changed, 35 insertions(+), 4 deletions(-)

diff --git a/tools/testing/selftests/net/busy_poll_test.sh b/tools/testing/selftests/net/busy_poll_test.sh
index 7db292ec4884..aeca610dc989 100755
--- a/tools/testing/selftests/net/busy_poll_test.sh
+++ b/tools/testing/selftests/net/busy_poll_test.sh
@@ -27,6 +27,9 @@ NAPI_DEFER_HARD_IRQS=100
 GRO_FLUSH_TIMEOUT=50000
 SUSPEND_TIMEOUT=20000000
 
+# NAPI threaded busy poll config
+NAPI_THREADED_POLL=2
+
 setup_ns()
 {
 	set -e
@@ -62,6 +65,9 @@ cleanup_ns()
 test_busypoll()
 {
 	suspend_value=${1:-0}
+	napi_threaded_value=${2:-0}
+	prefer_busy_poll_value=${3:-$PREFER_BUSY_POLL}
+
 	tmp_file=$(mktemp)
 	out_file=$(mktemp)
 
@@ -73,10 +79,11 @@ test_busypoll()
 					     -b${SERVER_IP}        \
 					     -m${MAX_EVENTS}       \
 					     -u${BUSY_POLL_USECS}  \
-					     -P${PREFER_BUSY_POLL} \
+					     -P${prefer_busy_poll_value} \
 					     -g${BUSY_POLL_BUDGET} \
 					     -i${NSIM_SV_IFIDX}    \
 					     -s${suspend_value}    \
+					     -t${napi_threaded_value} \
 					     -o${out_file}&
 
 	wait_local_port_listen nssv ${SERVER_PORT} tcp
@@ -109,6 +116,15 @@ test_busypoll_with_suspend()
 	return $?
 }
 
+test_busypoll_with_napi_threaded()
+{
+	# Only enable napi threaded poll. Set suspend timeout and prefer busy
+	# poll to 0.
+	test_busypoll 0 ${NAPI_THREADED_POLL} 0
+
+	return $?
+}
+
 ###
 ### Code start
 ###
@@ -154,6 +170,13 @@ if [ $? -ne 0 ]; then
 	exit 1
 fi
 
+test_busypoll_with_napi_threaded
+if [ $? -ne 0 ]; then
+	echo "test_busypoll_with_napi_threaded failed"
+	cleanup_ns
+	exit 1
+fi
+
 echo "$NSIM_SV_FD:$NSIM_SV_IFIDX" > $NSIM_DEV_SYS_UNLINK
 
 echo $NSIM_CL_ID > $NSIM_DEV_SYS_DEL
diff --git a/tools/testing/selftests/net/busy_poller.c b/tools/testing/selftests/net/busy_poller.c
index 04c7ff577bb8..f7407f09f635 100644
--- a/tools/testing/selftests/net/busy_poller.c
+++ b/tools/testing/selftests/net/busy_poller.c
@@ -65,15 +65,16 @@ static uint32_t cfg_busy_poll_usecs;
 static uint16_t cfg_busy_poll_budget;
 static uint8_t cfg_prefer_busy_poll;
 
-/* IRQ params */
+/* NAPI params */
 static uint32_t cfg_defer_hard_irqs;
 static uint64_t cfg_gro_flush_timeout;
 static uint64_t cfg_irq_suspend_timeout;
+static enum netdev_napi_threaded cfg_napi_threaded_poll = NETDEV_NAPI_THREADED_DISABLE;
 
 static void usage(const char *filepath)
 {
 	error(1, 0,
-	      "Usage: %s -p<port> -b<addr> -m<max_events> -u<busy_poll_usecs> -P<prefer_busy_poll> -g<busy_poll_budget> -o<outfile> -d<defer_hard_irqs> -r<gro_flush_timeout> -s<irq_suspend_timeout> -i<ifindex>",
+	      "Usage: %s -p<port> -b<addr> -m<max_events> -u<busy_poll_usecs> -P<prefer_busy_poll> -g<busy_poll_budget> -o<outfile> -d<defer_hard_irqs> -r<gro_flush_timeout> -s<irq_suspend_timeout> -t<napi_threaded_poll> -i<ifindex>",
 	      filepath);
 }
 
@@ -86,7 +87,7 @@ static void parse_opts(int argc, char **argv)
 	if (argc <= 1)
 		usage(argv[0]);
 
-	while ((c = getopt(argc, argv, "p:m:b:u:P:g:o:d:r:s:i:")) != -1) {
+	while ((c = getopt(argc, argv, "p:m:b:u:P:g:o:d:r:s:i:t:")) != -1) {
 		/* most options take integer values, except o and b, so reduce
 		 * code duplication a bit for the common case by calling
 		 * strtoull here and leave bounds checking and casting per
@@ -168,6 +169,12 @@ static void parse_opts(int argc, char **argv)
 
 			cfg_ifindex = (int)tmp;
 			break;
+		case 't':
+			if (tmp == ULLONG_MAX || tmp > 2)
+				error(1, ERANGE, "napi threaded poll value must be 0-2");
+
+			cfg_napi_threaded_poll = (enum netdev_napi_threaded)tmp;
+			break;
 		}
 	}
 
@@ -246,6 +253,7 @@ static void setup_queue(void)
 						  cfg_gro_flush_timeout);
 	netdev_napi_set_req_set_irq_suspend_timeout(set_req,
 						    cfg_irq_suspend_timeout);
+	netdev_napi_set_req_set_threaded(set_req, cfg_napi_threaded_poll);
 
 	if (netdev_napi_set(ys, set_req))
 		error(1, 0, "can't set NAPI params: %s\n", yerr.msg);
-- 
2.48.1.262.g85cc9f2d1e-goog

Re: [PATCH net-next v2 0/4] Add support to do threaded napi busy poll

[Jakub Kicinski]

On Thu, 23 Jan 2025 23:12:32 +0000 Samiullah Khawaja wrote:
> Extend the already existing support of threaded napi poll to do continuous
> busy polling.

## Form letter - net-next-closed

The merge window for v6.14 has begun and we have already posted our pull
request. Therefore net-next is closed for new drivers, features, code
refactoring and optimizations. We are currently accepting bug fixes only.

Please repost when net-next reopens after Feb 3rd.

RFC patches sent for review only are obviously welcome at any time.

See: https://www.kernel.org/doc/html/next/process/maintainer-netdev.html#development-cycle
-- 
pw-bot: defer
pv-bot: closed

Re: [PATCH net-next v2 3/4] Extend napi threaded polling to allow kthread based busy polling

[kernel test robot]

Hi Samiullah,

kernel test robot noticed the following build warnings:

[auto build test WARNING on net-next/main]

url:    https://github.com/intel-lab-lkp/linux/commits/Samiullah-Khawaja/Add-support-to-set-napi-threaded-for-individual-napi/20250124-071412
base:   net-next/main
patch link:    https://lore.kernel.org/r/20250123231236.2657321-4-skhawaja%40google.com
patch subject: [PATCH net-next v2 3/4] Extend napi threaded polling to allow kthread based busy polling
config: loongarch-allyesconfig (https://download.01.org/0day-ci/archive/20250124/202501242114.hSuOcqsi-lkp@intel.com/config)
compiler: loongarch64-linux-gcc (GCC) 14.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250124/202501242114.hSuOcqsi-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202501242114.hSuOcqsi-lkp@intel.com/

All warnings (new ones prefixed by >>):

   drivers/net/ethernet/renesas/ravb_main.c: In function 'ravb_probe':
>> drivers/net/ethernet/renesas/ravb_main.c:3078:48: warning: implicit conversion from 'enum <anonymous>' to 'enum netdev_napi_threaded' [-Wenum-conversion]
    3078 |                         dev_set_threaded(ndev, true);
         |                                                ^~~~
--
   drivers/net/ethernet/mellanox/mlxsw/pci.c: In function 'mlxsw_pci_napi_devs_init':
>> drivers/net/ethernet/mellanox/mlxsw/pci.c:159:50: warning: implicit conversion from 'enum <anonymous>' to 'enum netdev_napi_threaded' [-Wenum-conversion]
     159 |         dev_set_threaded(mlxsw_pci->napi_dev_rx, true);
         |                                                  ^~~~
--
   drivers/net/wireless/ath/ath10k/snoc.c: In function 'ath10k_snoc_hif_start':
>> drivers/net/wireless/ath/ath10k/snoc.c:938:40: warning: implicit conversion from 'enum <anonymous>' to 'enum netdev_napi_threaded' [-Wenum-conversion]
     938 |         dev_set_threaded(ar->napi_dev, true);
         |                                        ^~~~


vim +3078 drivers/net/ethernet/renesas/ravb_main.c

32f012b8c01ca9 drivers/net/ethernet/renesas/ravb_main.c Claudiu Beznea     2024-02-02  2901  
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  2902  static int ravb_probe(struct platform_device *pdev)
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  2903  {
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  2904  	struct device_node *np = pdev->dev.of_node;
ebb091461a9e14 drivers/net/ethernet/renesas/ravb_main.c Biju Das           2021-08-18  2905  	const struct ravb_hw_info *info;
0d13a1a464a023 drivers/net/ethernet/renesas/ravb_main.c Biju Das           2021-08-25  2906  	struct reset_control *rstc;
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  2907  	struct ravb_private *priv;
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  2908  	struct net_device *ndev;
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  2909  	struct resource *res;
32f012b8c01ca9 drivers/net/ethernet/renesas/ravb_main.c Claudiu Beznea     2024-02-02  2910  	int error, q;
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  2911  
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  2912  	if (!np) {
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  2913  		dev_err(&pdev->dev,
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  2914  			"this driver is required to be instantiated from device tree\n");
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  2915  		return -EINVAL;
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  2916  	}
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  2917  
b1768e3dc47792 drivers/net/ethernet/renesas/ravb_main.c Claudiu Beznea     2024-02-02  2918  	rstc = devm_reset_control_get_exclusive(&pdev->dev, NULL);
0d13a1a464a023 drivers/net/ethernet/renesas/ravb_main.c Biju Das           2021-08-25  2919  	if (IS_ERR(rstc))
0d13a1a464a023 drivers/net/ethernet/renesas/ravb_main.c Biju Das           2021-08-25  2920  		return dev_err_probe(&pdev->dev, PTR_ERR(rstc),
0d13a1a464a023 drivers/net/ethernet/renesas/ravb_main.c Biju Das           2021-08-25  2921  				     "failed to get cpg reset\n");
0d13a1a464a023 drivers/net/ethernet/renesas/ravb_main.c Biju Das           2021-08-25  2922  
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  2923  	ndev = alloc_etherdev_mqs(sizeof(struct ravb_private),
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  2924  				  NUM_TX_QUEUE, NUM_RX_QUEUE);
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  2925  	if (!ndev)
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  2926  		return -ENOMEM;
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  2927  
8912ed25daf6fc drivers/net/ethernet/renesas/ravb_main.c Biju Das           2021-08-18  2928  	info = of_device_get_match_data(&pdev->dev);
8912ed25daf6fc drivers/net/ethernet/renesas/ravb_main.c Biju Das           2021-08-18  2929  
8912ed25daf6fc drivers/net/ethernet/renesas/ravb_main.c Biju Das           2021-08-18  2930  	ndev->features = info->net_features;
8912ed25daf6fc drivers/net/ethernet/renesas/ravb_main.c Biju Das           2021-08-18  2931  	ndev->hw_features = info->net_hw_features;
546875ccba938b drivers/net/ethernet/renesas/ravb_main.c Paul Barker        2024-10-15  2932  	ndev->vlan_features = info->vlan_features;
4d86d381862714 drivers/net/ethernet/renesas/ravb_main.c Simon Horman       2017-10-04  2933  
d8eb6ea4b302e7 drivers/net/ethernet/renesas/ravb_main.c Claudiu Beznea     2023-11-28  2934  	error = reset_control_deassert(rstc);
d8eb6ea4b302e7 drivers/net/ethernet/renesas/ravb_main.c Claudiu Beznea     2023-11-28  2935  	if (error)
d8eb6ea4b302e7 drivers/net/ethernet/renesas/ravb_main.c Claudiu Beznea     2023-11-28  2936  		goto out_free_netdev;
d8eb6ea4b302e7 drivers/net/ethernet/renesas/ravb_main.c Claudiu Beznea     2023-11-28  2937  
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  2938  	SET_NETDEV_DEV(ndev, &pdev->dev);
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  2939  
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  2940  	priv = netdev_priv(ndev);
ebb091461a9e14 drivers/net/ethernet/renesas/ravb_main.c Biju Das           2021-08-18  2941  	priv->info = info;
0d13a1a464a023 drivers/net/ethernet/renesas/ravb_main.c Biju Das           2021-08-25  2942  	priv->rstc = rstc;
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  2943  	priv->ndev = ndev;
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  2944  	priv->pdev = pdev;
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  2945  	priv->num_tx_ring[RAVB_BE] = BE_TX_RING_SIZE;
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  2946  	priv->num_rx_ring[RAVB_BE] = BE_RX_RING_SIZE;
1091da579d7ccd drivers/net/ethernet/renesas/ravb_main.c Biju Das           2021-10-12  2947  	if (info->nc_queues) {
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  2948  		priv->num_tx_ring[RAVB_NC] = NC_TX_RING_SIZE;
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  2949  		priv->num_rx_ring[RAVB_NC] = NC_RX_RING_SIZE;
a92f4f0662bf2c drivers/net/ethernet/renesas/ravb_main.c Biju Das           2021-10-01  2950  	}
a92f4f0662bf2c drivers/net/ethernet/renesas/ravb_main.c Biju Das           2021-10-01  2951  
32f012b8c01ca9 drivers/net/ethernet/renesas/ravb_main.c Claudiu Beznea     2024-02-02  2952  	error = ravb_setup_irqs(priv);
32f012b8c01ca9 drivers/net/ethernet/renesas/ravb_main.c Claudiu Beznea     2024-02-02  2953  	if (error)
32f012b8c01ca9 drivers/net/ethernet/renesas/ravb_main.c Claudiu Beznea     2024-02-02  2954  		goto out_reset_assert;
32f012b8c01ca9 drivers/net/ethernet/renesas/ravb_main.c Claudiu Beznea     2024-02-02  2955  
a654f6e875b753 drivers/net/ethernet/renesas/ravb_main.c Claudiu Beznea     2024-02-02  2956  	priv->clk = devm_clk_get(&pdev->dev, NULL);
a654f6e875b753 drivers/net/ethernet/renesas/ravb_main.c Claudiu Beznea     2024-02-02  2957  	if (IS_ERR(priv->clk)) {
a654f6e875b753 drivers/net/ethernet/renesas/ravb_main.c Claudiu Beznea     2024-02-02  2958  		error = PTR_ERR(priv->clk);
a654f6e875b753 drivers/net/ethernet/renesas/ravb_main.c Claudiu Beznea     2024-02-02  2959  		goto out_reset_assert;
a654f6e875b753 drivers/net/ethernet/renesas/ravb_main.c Claudiu Beznea     2024-02-02  2960  	}
a654f6e875b753 drivers/net/ethernet/renesas/ravb_main.c Claudiu Beznea     2024-02-02  2961  
a654f6e875b753 drivers/net/ethernet/renesas/ravb_main.c Claudiu Beznea     2024-02-02  2962  	if (info->gptp_ref_clk) {
a654f6e875b753 drivers/net/ethernet/renesas/ravb_main.c Claudiu Beznea     2024-02-02  2963  		priv->gptp_clk = devm_clk_get(&pdev->dev, "gptp");
a654f6e875b753 drivers/net/ethernet/renesas/ravb_main.c Claudiu Beznea     2024-02-02  2964  		if (IS_ERR(priv->gptp_clk)) {
a654f6e875b753 drivers/net/ethernet/renesas/ravb_main.c Claudiu Beznea     2024-02-02  2965  			error = PTR_ERR(priv->gptp_clk);
a654f6e875b753 drivers/net/ethernet/renesas/ravb_main.c Claudiu Beznea     2024-02-02  2966  			goto out_reset_assert;
a654f6e875b753 drivers/net/ethernet/renesas/ravb_main.c Claudiu Beznea     2024-02-02  2967  		}
a654f6e875b753 drivers/net/ethernet/renesas/ravb_main.c Claudiu Beznea     2024-02-02  2968  	}
a654f6e875b753 drivers/net/ethernet/renesas/ravb_main.c Claudiu Beznea     2024-02-02  2969  
a654f6e875b753 drivers/net/ethernet/renesas/ravb_main.c Claudiu Beznea     2024-02-02  2970  	priv->refclk = devm_clk_get_optional(&pdev->dev, "refclk");
a654f6e875b753 drivers/net/ethernet/renesas/ravb_main.c Claudiu Beznea     2024-02-02  2971  	if (IS_ERR(priv->refclk)) {
a654f6e875b753 drivers/net/ethernet/renesas/ravb_main.c Claudiu Beznea     2024-02-02  2972  		error = PTR_ERR(priv->refclk);
a654f6e875b753 drivers/net/ethernet/renesas/ravb_main.c Claudiu Beznea     2024-02-02  2973  		goto out_reset_assert;
a654f6e875b753 drivers/net/ethernet/renesas/ravb_main.c Claudiu Beznea     2024-02-02  2974  	}
a654f6e875b753 drivers/net/ethernet/renesas/ravb_main.c Claudiu Beznea     2024-02-02  2975  	clk_prepare(priv->refclk);
a654f6e875b753 drivers/net/ethernet/renesas/ravb_main.c Claudiu Beznea     2024-02-02  2976  
a654f6e875b753 drivers/net/ethernet/renesas/ravb_main.c Claudiu Beznea     2024-02-02  2977  	platform_set_drvdata(pdev, ndev);
48f894ab07c444 drivers/net/ethernet/renesas/ravb_main.c Claudiu Beznea     2024-02-14  2978  	pm_runtime_set_autosuspend_delay(&pdev->dev, 100);
48f894ab07c444 drivers/net/ethernet/renesas/ravb_main.c Claudiu Beznea     2024-02-14  2979  	pm_runtime_use_autosuspend(&pdev->dev);
a654f6e875b753 drivers/net/ethernet/renesas/ravb_main.c Claudiu Beznea     2024-02-02  2980  	pm_runtime_enable(&pdev->dev);
a654f6e875b753 drivers/net/ethernet/renesas/ravb_main.c Claudiu Beznea     2024-02-02  2981  	error = pm_runtime_resume_and_get(&pdev->dev);
a654f6e875b753 drivers/net/ethernet/renesas/ravb_main.c Claudiu Beznea     2024-02-02  2982  	if (error < 0)
a654f6e875b753 drivers/net/ethernet/renesas/ravb_main.c Claudiu Beznea     2024-02-02  2983  		goto out_rpm_disable;
a654f6e875b753 drivers/net/ethernet/renesas/ravb_main.c Claudiu Beznea     2024-02-02  2984  
e89a2cdb1cca51 drivers/net/ethernet/renesas/ravb_main.c Yang Yingliang     2021-06-09  2985  	priv->addr = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  2986  	if (IS_ERR(priv->addr)) {
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  2987  		error = PTR_ERR(priv->addr);
a654f6e875b753 drivers/net/ethernet/renesas/ravb_main.c Claudiu Beznea     2024-02-02  2988  		goto out_rpm_put;
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  2989  	}
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  2990  
e89a2cdb1cca51 drivers/net/ethernet/renesas/ravb_main.c Yang Yingliang     2021-06-09  2991  	/* The Ether-specific entries in the device structure. */
e89a2cdb1cca51 drivers/net/ethernet/renesas/ravb_main.c Yang Yingliang     2021-06-09  2992  	ndev->base_addr = res->start;
e89a2cdb1cca51 drivers/net/ethernet/renesas/ravb_main.c Yang Yingliang     2021-06-09  2993  
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  2994  	spin_lock_init(&priv->lock);
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  2995  	INIT_WORK(&priv->work, ravb_tx_timeout_work);
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  2996  
0c65b2b90d13c1 drivers/net/ethernet/renesas/ravb_main.c Andrew Lunn        2019-11-04  2997  	error = of_get_phy_mode(np, &priv->phy_interface);
0c65b2b90d13c1 drivers/net/ethernet/renesas/ravb_main.c Andrew Lunn        2019-11-04  2998  	if (error && error != -ENODEV)
a654f6e875b753 drivers/net/ethernet/renesas/ravb_main.c Claudiu Beznea     2024-02-02  2999  		goto out_rpm_put;
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  3000  
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  3001  	priv->no_avb_link = of_property_read_bool(np, "renesas,no-ether-link");
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  3002  	priv->avb_link_active_low =
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  3003  		of_property_read_bool(np, "renesas,ether-link-active-low");
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  3004  
1d63864299cafa drivers/net/ethernet/renesas/ravb_main.c Paul Barker        2024-09-18  3005  	ndev->max_mtu = info->tx_max_frame_size -
e82700b8662ce5 drivers/net/ethernet/renesas/ravb_main.c Niklas Söderlund   2024-03-04  3006  		(ETH_HLEN + VLAN_HLEN + ETH_FCS_LEN);
75efa06f457bbe drivers/net/ethernet/renesas/ravb_main.c Niklas Söderlund   2018-02-16  3007  	ndev->min_mtu = ETH_MIN_MTU;
75efa06f457bbe drivers/net/ethernet/renesas/ravb_main.c Niklas Söderlund   2018-02-16  3008  
c81d894226b944 drivers/net/ethernet/renesas/ravb_main.c Biju Das           2021-08-25  3009  	/* FIXME: R-Car Gen2 has 4byte alignment restriction for tx buffer
c81d894226b944 drivers/net/ethernet/renesas/ravb_main.c Biju Das           2021-08-25  3010  	 * Use two descriptor to handle such situation. First descriptor to
c81d894226b944 drivers/net/ethernet/renesas/ravb_main.c Biju Das           2021-08-25  3011  	 * handle aligned data buffer and second descriptor to handle the
c81d894226b944 drivers/net/ethernet/renesas/ravb_main.c Biju Das           2021-08-25  3012  	 * overflow data because of alignment.
c81d894226b944 drivers/net/ethernet/renesas/ravb_main.c Biju Das           2021-08-25  3013  	 */
c81d894226b944 drivers/net/ethernet/renesas/ravb_main.c Biju Das           2021-08-25  3014  	priv->num_tx_desc = info->aligned_tx ? 2 : 1;
f543305da9b5a5 drivers/net/ethernet/renesas/ravb_main.c Kazuya Mizuguchi   2018-09-19  3015  
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  3016  	/* Set function */
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  3017  	ndev->netdev_ops = &ravb_netdev_ops;
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  3018  	ndev->ethtool_ops = &ravb_ethtool_ops;
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  3019  
f384ab481cab6a drivers/net/ethernet/renesas/ravb_main.c Claudiu Beznea     2024-02-02  3020  	error = ravb_compute_gti(ndev);
b3d39a8805c510 drivers/net/ethernet/renesas/ravb_main.c Simon Horman       2015-11-20  3021  	if (error)
a654f6e875b753 drivers/net/ethernet/renesas/ravb_main.c Claudiu Beznea     2024-02-02  3022  		goto out_rpm_put;
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  3023  
a6f51f2efa742d drivers/net/ethernet/renesas/ravb_main.c Geert Uytterhoeven 2020-10-01  3024  	ravb_parse_delay_mode(np, ndev);
61fccb2d6274f7 drivers/net/ethernet/renesas/ravb_main.c Kazuya Mizuguchi   2017-01-27  3025  
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  3026  	/* Allocate descriptor base address table */
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  3027  	priv->desc_bat_size = sizeof(struct ravb_desc) * DBAT_ENTRY_NUM;
e2dbb33ad9545d drivers/net/ethernet/renesas/ravb_main.c Kazuya Mizuguchi   2015-09-30  3028  	priv->desc_bat = dma_alloc_coherent(ndev->dev.parent, priv->desc_bat_size,
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  3029  					    &priv->desc_bat_dma, GFP_KERNEL);
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  3030  	if (!priv->desc_bat) {
c451113291c193 drivers/net/ethernet/renesas/ravb_main.c Simon Horman       2015-11-02  3031  		dev_err(&pdev->dev,
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  3032  			"Cannot allocate desc base address table (size %d bytes)\n",
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  3033  			priv->desc_bat_size);
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  3034  		error = -ENOMEM;
a654f6e875b753 drivers/net/ethernet/renesas/ravb_main.c Claudiu Beznea     2024-02-02  3035  		goto out_rpm_put;
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  3036  	}
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  3037  	for (q = RAVB_BE; q < DBAT_ENTRY_NUM; q++)
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  3038  		priv->desc_bat[q].die_dt = DT_EOS;
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  3039  
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  3040  	/* Initialise HW timestamp list */
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  3041  	INIT_LIST_HEAD(&priv->ts_skb_list);
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  3042  
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  3043  	/* Debug message level */
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  3044  	priv->msg_enable = RAVB_DEF_MSG_ENABLE;
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  3045  
76fd52c1007785 drivers/net/ethernet/renesas/ravb_main.c Claudiu Beznea     2024-02-02  3046  	/* Set config mode as this is needed for PHY initialization. */
76fd52c1007785 drivers/net/ethernet/renesas/ravb_main.c Claudiu Beznea     2024-02-02  3047  	error = ravb_set_opmode(ndev, CCC_OPC_CONFIG);
76fd52c1007785 drivers/net/ethernet/renesas/ravb_main.c Claudiu Beznea     2024-02-02  3048  	if (error)
76fd52c1007785 drivers/net/ethernet/renesas/ravb_main.c Claudiu Beznea     2024-02-02  3049  		goto out_rpm_put;
76fd52c1007785 drivers/net/ethernet/renesas/ravb_main.c Claudiu Beznea     2024-02-02  3050  
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  3051  	/* Read and set MAC address */
83216e3988cd19 drivers/net/ethernet/renesas/ravb_main.c Michael Walle      2021-04-12  3052  	ravb_read_mac_address(np, ndev);
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  3053  	if (!is_valid_ether_addr(ndev->dev_addr)) {
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  3054  		dev_warn(&pdev->dev,
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  3055  			 "no valid MAC address supplied, using a random one\n");
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  3056  		eth_hw_addr_random(ndev);
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  3057  	}
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  3058  
77972b55fb9d35 drivers/net/ethernet/renesas/ravb_main.c Geert Uytterhoeven 2020-09-22  3059  	/* MDIO bus init */
77972b55fb9d35 drivers/net/ethernet/renesas/ravb_main.c Geert Uytterhoeven 2020-09-22  3060  	error = ravb_mdio_init(priv);
77972b55fb9d35 drivers/net/ethernet/renesas/ravb_main.c Geert Uytterhoeven 2020-09-22  3061  	if (error) {
77972b55fb9d35 drivers/net/ethernet/renesas/ravb_main.c Geert Uytterhoeven 2020-09-22  3062  		dev_err(&pdev->dev, "failed to initialize MDIO\n");
76fd52c1007785 drivers/net/ethernet/renesas/ravb_main.c Claudiu Beznea     2024-02-02  3063  		goto out_reset_mode;
77972b55fb9d35 drivers/net/ethernet/renesas/ravb_main.c Geert Uytterhoeven 2020-09-22  3064  	}
77972b55fb9d35 drivers/net/ethernet/renesas/ravb_main.c Geert Uytterhoeven 2020-09-22  3065  
76fd52c1007785 drivers/net/ethernet/renesas/ravb_main.c Claudiu Beznea     2024-02-02  3066  	/* Undo previous switch to config opmode. */
76fd52c1007785 drivers/net/ethernet/renesas/ravb_main.c Claudiu Beznea     2024-02-02  3067  	error = ravb_set_opmode(ndev, CCC_OPC_RESET);
76fd52c1007785 drivers/net/ethernet/renesas/ravb_main.c Claudiu Beznea     2024-02-02  3068  	if (error)
76fd52c1007785 drivers/net/ethernet/renesas/ravb_main.c Claudiu Beznea     2024-02-02  3069  		goto out_mdio_release;
76fd52c1007785 drivers/net/ethernet/renesas/ravb_main.c Claudiu Beznea     2024-02-02  3070  
b48b89f9c189d2 drivers/net/ethernet/renesas/ravb_main.c Jakub Kicinski     2022-09-27  3071  	netif_napi_add(ndev, &priv->napi[RAVB_BE], ravb_poll);
1091da579d7ccd drivers/net/ethernet/renesas/ravb_main.c Biju Das           2021-10-12  3072  	if (info->nc_queues)
b48b89f9c189d2 drivers/net/ethernet/renesas/ravb_main.c Jakub Kicinski     2022-09-27  3073  		netif_napi_add(ndev, &priv->napi[RAVB_NC], ravb_poll);
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  3074  
65c482bc226ab2 drivers/net/ethernet/renesas/ravb_main.c Paul Barker        2024-06-04  3075  	if (info->coalesce_irqs) {
7b39c1814ce3bc drivers/net/ethernet/renesas/ravb_main.c Paul Barker        2024-06-04  3076  		netdev_sw_irq_coalesce_default_on(ndev);
65c482bc226ab2 drivers/net/ethernet/renesas/ravb_main.c Paul Barker        2024-06-04  3077  		if (num_present_cpus() == 1)
65c482bc226ab2 drivers/net/ethernet/renesas/ravb_main.c Paul Barker        2024-06-04 @3078  			dev_set_threaded(ndev, true);
65c482bc226ab2 drivers/net/ethernet/renesas/ravb_main.c Paul Barker        2024-06-04  3079  	}
7b39c1814ce3bc drivers/net/ethernet/renesas/ravb_main.c Paul Barker        2024-06-04  3080  
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  3081  	/* Network device register */
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  3082  	error = register_netdev(ndev);
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  3083  	if (error)
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  3084  		goto out_napi_del;
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  3085  
3e3d647715d401 drivers/net/ethernet/renesas/ravb_main.c Niklas Söderlund   2017-08-01  3086  	device_set_wakeup_capable(&pdev->dev, 1);
3e3d647715d401 drivers/net/ethernet/renesas/ravb_main.c Niklas Söderlund   2017-08-01  3087  
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  3088  	/* Print device information */
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  3089  	netdev_info(ndev, "Base address at %#x, %pM, IRQ %d.\n",
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  3090  		    (u32)ndev->base_addr, ndev->dev_addr, ndev->irq);
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  3091  
48f894ab07c444 drivers/net/ethernet/renesas/ravb_main.c Claudiu Beznea     2024-02-14  3092  	pm_runtime_mark_last_busy(&pdev->dev);
48f894ab07c444 drivers/net/ethernet/renesas/ravb_main.c Claudiu Beznea     2024-02-14  3093  	pm_runtime_put_autosuspend(&pdev->dev);
48f894ab07c444 drivers/net/ethernet/renesas/ravb_main.c Claudiu Beznea     2024-02-14  3094  
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  3095  	return 0;
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  3096  
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  3097  out_napi_del:
1091da579d7ccd drivers/net/ethernet/renesas/ravb_main.c Biju Das           2021-10-12  3098  	if (info->nc_queues)
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  3099  		netif_napi_del(&priv->napi[RAVB_NC]);
a92f4f0662bf2c drivers/net/ethernet/renesas/ravb_main.c Biju Das           2021-10-01  3100  
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  3101  	netif_napi_del(&priv->napi[RAVB_BE]);
76fd52c1007785 drivers/net/ethernet/renesas/ravb_main.c Claudiu Beznea     2024-02-02  3102  out_mdio_release:
77972b55fb9d35 drivers/net/ethernet/renesas/ravb_main.c Geert Uytterhoeven 2020-09-22  3103  	ravb_mdio_release(priv);
76fd52c1007785 drivers/net/ethernet/renesas/ravb_main.c Claudiu Beznea     2024-02-02  3104  out_reset_mode:
76fd52c1007785 drivers/net/ethernet/renesas/ravb_main.c Claudiu Beznea     2024-02-02  3105  	ravb_set_opmode(ndev, CCC_OPC_RESET);
e2dbb33ad9545d drivers/net/ethernet/renesas/ravb_main.c Kazuya Mizuguchi   2015-09-30  3106  	dma_free_coherent(ndev->dev.parent, priv->desc_bat_size, priv->desc_bat,
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  3107  			  priv->desc_bat_dma);
a654f6e875b753 drivers/net/ethernet/renesas/ravb_main.c Claudiu Beznea     2024-02-02  3108  out_rpm_put:
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  3109  	pm_runtime_put(&pdev->dev);
88b74831faaee4 drivers/net/ethernet/renesas/ravb_main.c Claudiu Beznea     2023-11-28  3110  out_rpm_disable:
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  3111  	pm_runtime_disable(&pdev->dev);
48f894ab07c444 drivers/net/ethernet/renesas/ravb_main.c Claudiu Beznea     2024-02-14  3112  	pm_runtime_dont_use_autosuspend(&pdev->dev);
a654f6e875b753 drivers/net/ethernet/renesas/ravb_main.c Claudiu Beznea     2024-02-02  3113  	clk_unprepare(priv->refclk);
a654f6e875b753 drivers/net/ethernet/renesas/ravb_main.c Claudiu Beznea     2024-02-02  3114  out_reset_assert:
0d13a1a464a023 drivers/net/ethernet/renesas/ravb_main.c Biju Das           2021-08-25  3115  	reset_control_assert(rstc);
d8eb6ea4b302e7 drivers/net/ethernet/renesas/ravb_main.c Claudiu Beznea     2023-11-28  3116  out_free_netdev:
d8eb6ea4b302e7 drivers/net/ethernet/renesas/ravb_main.c Claudiu Beznea     2023-11-28  3117  	free_netdev(ndev);
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  3118  	return error;
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  3119  }
c156633f135326 drivers/net/ethernet/renesas/ravb.c      Sergei Shtylyov    2015-06-11  3120  

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

Re: [PATCH net-next v2 0/4] Add support to do threaded napi busy poll

[Joe Damato]

On Thu, Jan 23, 2025 at 11:12:32PM +0000, Samiullah Khawaja wrote:
> Extend the already existing support of threaded napi poll to do continuous
> busy polling.
> 
> This is used for doing continuous polling of napi to fetch descriptors from
> backing RX/TX queues for low latency applications. Allow enabling of threaded
> busypoll using netlink so this can be enabled on a set of dedicated napis for
> low latency applications.
> 
> It allows enabling NAPI busy poll for any userspace application
> indepdendent of userspace API being used for packet and event processing
> (epoll, io_uring, raw socket APIs). Once enabled user can fetch the PID
> of the kthread doing NAPI polling and set affinity, priority and
> scheduler for it depending on the low-latency requirements.

When you resubmit this after the merge window (or if you resubmit it
as an RFC), would you mind CCing both me (jdamato@fastly.com) and
Martin (mkarsten@uwaterloo.ca) ?

We almost missed this revision after commenting on the previous
version, since we weren't included in the CC list.

Both Martin and I read through the cover letter and proposed changes
and have several questions/comments, but given that the thread is
marked as deferred/closed due to the merge window, we'll hold off
on digging in until the next revision is posted.