diff mbox series

[v3,08/11] can: bcm: Add LIN answer offloading for responder mode

Message ID 20240502182804.145926-9-christoph.fritz@hexdev.de (mailing list archive)
State Superseded
Headers show
Series LIN Bus support for Linux | expand

Commit Message

Christoph Fritz May 2, 2024, 6:28 p.m. UTC 
Enhance CAN broadcast manager with RX_LIN_SETUP and RX_LIN_DELETE
operations to setup automatic LIN frame responses in responder mode.

Additionally, the patch introduces the LIN_EVENT_FRAME flag to
setup event-triggered LIN frames.

Signed-off-by: Christoph Fritz <christoph.fritz@hexdev.de>
---
 include/uapi/linux/can/bcm.h |  5 ++-
 net/can/bcm.c                | 74 +++++++++++++++++++++++++++++++++++-
 2 files changed, 77 insertions(+), 2 deletions(-)

Comments

Ilpo Järvinen May 6, 2024, 5:08 p.m. UTC | #1 
On Thu, 2 May 2024, Christoph Fritz wrote:

> Enhance CAN broadcast manager with RX_LIN_SETUP and RX_LIN_DELETE
> operations to setup automatic LIN frame responses in responder mode.
> 
> Additionally, the patch introduces the LIN_EVENT_FRAME flag to
> setup event-triggered LIN frames.
> 
> Signed-off-by: Christoph Fritz <christoph.fritz@hexdev.de>
> ---
>  include/uapi/linux/can/bcm.h |  5 ++-
>  net/can/bcm.c                | 74 +++++++++++++++++++++++++++++++++++-
>  2 files changed, 77 insertions(+), 2 deletions(-)
> 
> diff --git a/include/uapi/linux/can/bcm.h b/include/uapi/linux/can/bcm.h
> index f1e45f533a72c..c46268a114078 100644
> --- a/include/uapi/linux/can/bcm.h
> +++ b/include/uapi/linux/can/bcm.h
> @@ -86,7 +86,9 @@ enum {
>  	TX_EXPIRED,	/* notification on performed transmissions (count=0) */
>  	RX_STATUS,	/* reply to RX_READ request */
>  	RX_TIMEOUT,	/* cyclic message is absent */
> -	RX_CHANGED	/* updated CAN frame (detected content change) */
> +	RX_CHANGED,	/* updated CAN frame (detected content change) */
> +	RX_LIN_SETUP,	/* create auto-response for LIN frame */
> +	RX_LIN_DELETE,  /* remove auto-response for LIN frame */
>  };
>  
>  #define SETTIMER            0x0001
> @@ -101,5 +103,6 @@ enum {
>  #define TX_RESET_MULTI_IDX  0x0200
>  #define RX_RTR_FRAME        0x0400
>  #define CAN_FD_FRAME        0x0800
> +#define LIN_EVENT_FRAME     0x1000
>  
>  #endif /* !_UAPI_CAN_BCM_H */
> diff --git a/net/can/bcm.c b/net/can/bcm.c
> index 27d5fcf0eac9d..a717e594234d1 100644
> --- a/net/can/bcm.c
> +++ b/net/can/bcm.c
> @@ -59,6 +59,7 @@
>  #include <linux/can/bcm.h>
>  #include <linux/slab.h>
>  #include <net/sock.h>
> +#include <net/lin.h>
>  #include <net/net_namespace.h>
>  
>  /*
> @@ -1330,6 +1331,59 @@ static int bcm_tx_send(struct msghdr *msg, int ifindex, struct sock *sk,
>  	return cfsiz + MHSIZ;
>  }
>  
> +static int bcm_lin_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
> +			 int ifindex, struct sock *sk, int cfsiz, int is_active)
> +{
> +	struct lin_responder_answer answ;
> +	struct net_device *dev;
> +	struct sk_buff *skb;
> +	struct canfd_frame cf;
> +	netdevice_tracker tracker;
> +	size_t sz;
> +	int ret;
> +
> +	if (msg_head->nframes > 1)
> +		return -EINVAL;
> +
> +	if (!(msg_head->flags & CAN_FD_FRAME))
> +		return -EINVAL;
> +
> +	ret = memcpy_from_msg(&cf, msg, cfsiz);
> +	if (ret < 0)
> +		return ret;
> +
> +	answ.lf.lin_id = cf.can_id & LIN_ID_MASK;
> +	answ.is_active = is_active;
> +	answ.is_event_frame = !!(msg_head->flags & LIN_EVENT_FRAME);
> +	answ.event_associated_id = msg_head->can_id;
> +	answ.lf.len = min(cf.len, LIN_MAX_DLEN);
> +	memcpy(answ.lf.data, cf.data, answ.lf.len);
> +	sz = min(sizeof(struct lin_responder_answer), sizeof(cf.data));
> +	cf.can_id |= LIN_RXOFFLOAD_DATA_FLAG;
> +	memcpy(cf.data, &answ, sz);
> +
> +	dev = netdev_get_by_index(sock_net(sk), ifindex, &tracker, GFP_KERNEL);
> +	if (!dev)
> +		return -ENODEV;
> +
> +	skb = alloc_skb(cfsiz + sizeof(struct can_skb_priv), gfp_any());

You just called the other function with GFP_KERNEL and you now need 
gfp_any(). Which is correct??

> +	if (!skb)
> +		goto lin_out;
> +
> +	can_skb_reserve(skb);
> +	can_skb_prv(skb)->ifindex = dev->ifindex;
> +	can_skb_prv(skb)->skbcnt = 0;
> +	skb_put_data(skb, &cf, cfsiz);
> +
> +	skb->dev = dev;
> +	can_skb_set_owner(skb, sk);
> +	ret = can_send(skb, 1); /* send with loopback */
> +
> +lin_out:
> +	netdev_put(dev, &tracker);
> +	return ret;
> +}
> +
>  /*
>   * bcm_sendmsg - process BCM commands (opcodes) from the userspace
>   */
> @@ -1429,12 +1483,30 @@ static int bcm_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
>  
>  	case TX_SEND:
>  		/* we need exactly one CAN frame behind the msg head */
> -		if ((msg_head.nframes != 1) || (size != cfsiz + MHSIZ))
> +		if (msg_head.nframes != 1 || size != cfsiz + MHSIZ)

Unrelated style fix, doesn't belong to this patch.

>  			ret = -EINVAL;
>  		else
>  			ret = bcm_tx_send(msg, ifindex, sk, cfsiz);
>  		break;
>  
> +	case RX_LIN_SETUP:
> +		/* we need exactly one CAN frame behind the msg head */
> +		if (msg_head.nframes != 1 || size != cfsiz + MHSIZ)
> +			ret = -EINVAL;
> +		else
> +			ret = bcm_lin_setup(&msg_head, msg, ifindex, sk, cfsiz,
> +					    1);
> +		break;
> +
> +	case RX_LIN_DELETE:
> +		/* we need exactly one CAN frame behind the msg head */
> +		if (msg_head.nframes != 1 || size != cfsiz + MHSIZ)
> +			ret = -EINVAL;
> +		else
> +			ret = bcm_lin_setup(&msg_head, msg, ifindex, sk, cfsiz,
> +					    0);
> +		break;
> +
>  	default:
>  		ret = -EINVAL;
>  		break;
>
Christoph Fritz May 9, 2024, 5:06 p.m. UTC | #2 
On Mon, 2024-05-06 at 20:08 +0300, Ilpo Järvinen wrote:
> On Thu, 2 May 2024, Christoph Fritz wrote:
> 
> > Enhance CAN broadcast manager with RX_LIN_SETUP and RX_LIN_DELETE
> > operations to setup automatic LIN frame responses in responder mode.
> > 
> > Additionally, the patch introduces the LIN_EVENT_FRAME flag to
> > setup event-triggered LIN frames.
> > 
> > Signed-off-by: Christoph Fritz <christoph.fritz@hexdev.de>
> > ---
> >  include/uapi/linux/can/bcm.h |  5 ++-
> >  net/can/bcm.c                | 74 +++++++++++++++++++++++++++++++++++-
> >  2 files changed, 77 insertions(+), 2 deletions(-)
> > 
> > diff --git a/include/uapi/linux/can/bcm.h b/include/uapi/linux/can/bcm.h
> > index f1e45f533a72c..c46268a114078 100644
> > --- a/include/uapi/linux/can/bcm.h
> > +++ b/include/uapi/linux/can/bcm.h
> > @@ -86,7 +86,9 @@ enum {
> >  	TX_EXPIRED,	/* notification on performed transmissions (count=0) */
> >  	RX_STATUS,	/* reply to RX_READ request */
> >  	RX_TIMEOUT,	/* cyclic message is absent */
> > -	RX_CHANGED	/* updated CAN frame (detected content change) */
> > +	RX_CHANGED,	/* updated CAN frame (detected content change) */
> > +	RX_LIN_SETUP,	/* create auto-response for LIN frame */
> > +	RX_LIN_DELETE,  /* remove auto-response for LIN frame */
> >  };
> >  
> >  #define SETTIMER            0x0001
> > @@ -101,5 +103,6 @@ enum {
> >  #define TX_RESET_MULTI_IDX  0x0200
> >  #define RX_RTR_FRAME        0x0400
> >  #define CAN_FD_FRAME        0x0800
> > +#define LIN_EVENT_FRAME     0x1000
> >  
> >  #endif /* !_UAPI_CAN_BCM_H */
> > diff --git a/net/can/bcm.c b/net/can/bcm.c
> > index 27d5fcf0eac9d..a717e594234d1 100644
> > --- a/net/can/bcm.c
> > +++ b/net/can/bcm.c
> > @@ -59,6 +59,7 @@
> >  #include <linux/can/bcm.h>
> >  #include <linux/slab.h>
> >  #include <net/sock.h>
> > +#include <net/lin.h>
> >  #include <net/net_namespace.h>
> >  
> >  /*
> > @@ -1330,6 +1331,59 @@ static int bcm_tx_send(struct msghdr *msg, int ifindex, struct sock *sk,
> >  	return cfsiz + MHSIZ;
> >  }
> >  
> > +static int bcm_lin_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
> > +			 int ifindex, struct sock *sk, int cfsiz, int is_active)
> > +{
> > +	struct lin_responder_answer answ;
> > +	struct net_device *dev;
> > +	struct sk_buff *skb;
> > +	struct canfd_frame cf;
> > +	netdevice_tracker tracker;
> > +	size_t sz;
> > +	int ret;
> > +
> > +	if (msg_head->nframes > 1)
> > +		return -EINVAL;
> > +
> > +	if (!(msg_head->flags & CAN_FD_FRAME))
> > +		return -EINVAL;
> > +
> > +	ret = memcpy_from_msg(&cf, msg, cfsiz);
> > +	if (ret < 0)
> > +		return ret;
> > +
> > +	answ.lf.lin_id = cf.can_id & LIN_ID_MASK;
> > +	answ.is_active = is_active;
> > +	answ.is_event_frame = !!(msg_head->flags & LIN_EVENT_FRAME);
> > +	answ.event_associated_id = msg_head->can_id;
> > +	answ.lf.len = min(cf.len, LIN_MAX_DLEN);
> > +	memcpy(answ.lf.data, cf.data, answ.lf.len);
> > +	sz = min(sizeof(struct lin_responder_answer), sizeof(cf.data));
> > +	cf.can_id |= LIN_RXOFFLOAD_DATA_FLAG;
> > +	memcpy(cf.data, &answ, sz);
> > +
> > +	dev = netdev_get_by_index(sock_net(sk), ifindex, &tracker, GFP_KERNEL);
> > +	if (!dev)
> > +		return -ENODEV;
> > +
> > +	skb = alloc_skb(cfsiz + sizeof(struct can_skb_priv), gfp_any());
> 
> You just called the other function with GFP_KERNEL and you now need 
> gfp_any(). Which is correct??

I guess GFP_KERNEL but I'm not sure so I'll let gfp_any() decide for
netdev_get_by_index() too.

> 
> > +	if (!skb)
> > +		goto lin_out;
> > +
> > +	can_skb_reserve(skb);
> > +	can_skb_prv(skb)->ifindex = dev->ifindex;
> > +	can_skb_prv(skb)->skbcnt = 0;
> > +	skb_put_data(skb, &cf, cfsiz);
> > +
> > +	skb->dev = dev;
> > +	can_skb_set_owner(skb, sk);
> > +	ret = can_send(skb, 1); /* send with loopback */
> > +
> > +lin_out:
> > +	netdev_put(dev, &tracker);
> > +	return ret;
> > +}
> > +
> >  /*
> >   * bcm_sendmsg - process BCM commands (opcodes) from the userspace
> >   */
> > @@ -1429,12 +1483,30 @@ static int bcm_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
> >  
> >  	case TX_SEND:
> >  		/* we need exactly one CAN frame behind the msg head */
> > -		if ((msg_head.nframes != 1) || (size != cfsiz + MHSIZ))
> > +		if (msg_head.nframes != 1 || size != cfsiz + MHSIZ)
> 
> Unrelated style fix, doesn't belong to this patch.

OK

...

thanks
  -- Christoph
diff mbox series

Patch

diff --git a/include/uapi/linux/can/bcm.h b/include/uapi/linux/can/bcm.h
index f1e45f533a72c..c46268a114078 100644
--- a/include/uapi/linux/can/bcm.h
+++ b/include/uapi/linux/can/bcm.h
@@ -86,7 +86,9 @@  enum {
 	TX_EXPIRED,	/* notification on performed transmissions (count=0) */
 	RX_STATUS,	/* reply to RX_READ request */
 	RX_TIMEOUT,	/* cyclic message is absent */
-	RX_CHANGED	/* updated CAN frame (detected content change) */
+	RX_CHANGED,	/* updated CAN frame (detected content change) */
+	RX_LIN_SETUP,	/* create auto-response for LIN frame */
+	RX_LIN_DELETE,  /* remove auto-response for LIN frame */
 };
 
 #define SETTIMER            0x0001
@@ -101,5 +103,6 @@  enum {
 #define TX_RESET_MULTI_IDX  0x0200
 #define RX_RTR_FRAME        0x0400
 #define CAN_FD_FRAME        0x0800
+#define LIN_EVENT_FRAME     0x1000
 
 #endif /* !_UAPI_CAN_BCM_H */
diff --git a/net/can/bcm.c b/net/can/bcm.c
index 27d5fcf0eac9d..a717e594234d1 100644
--- a/net/can/bcm.c
+++ b/net/can/bcm.c
@@ -59,6 +59,7 @@ 
 #include <linux/can/bcm.h>
 #include <linux/slab.h>
 #include <net/sock.h>
+#include <net/lin.h>
 #include <net/net_namespace.h>
 
 /*
@@ -1330,6 +1331,59 @@  static int bcm_tx_send(struct msghdr *msg, int ifindex, struct sock *sk,
 	return cfsiz + MHSIZ;
 }
 
+static int bcm_lin_setup(struct bcm_msg_head *msg_head, struct msghdr *msg,
+			 int ifindex, struct sock *sk, int cfsiz, int is_active)
+{
+	struct lin_responder_answer answ;
+	struct net_device *dev;
+	struct sk_buff *skb;
+	struct canfd_frame cf;
+	netdevice_tracker tracker;
+	size_t sz;
+	int ret;
+
+	if (msg_head->nframes > 1)
+		return -EINVAL;
+
+	if (!(msg_head->flags & CAN_FD_FRAME))
+		return -EINVAL;
+
+	ret = memcpy_from_msg(&cf, msg, cfsiz);
+	if (ret < 0)
+		return ret;
+
+	answ.lf.lin_id = cf.can_id & LIN_ID_MASK;
+	answ.is_active = is_active;
+	answ.is_event_frame = !!(msg_head->flags & LIN_EVENT_FRAME);
+	answ.event_associated_id = msg_head->can_id;
+	answ.lf.len = min(cf.len, LIN_MAX_DLEN);
+	memcpy(answ.lf.data, cf.data, answ.lf.len);
+	sz = min(sizeof(struct lin_responder_answer), sizeof(cf.data));
+	cf.can_id |= LIN_RXOFFLOAD_DATA_FLAG;
+	memcpy(cf.data, &answ, sz);
+
+	dev = netdev_get_by_index(sock_net(sk), ifindex, &tracker, GFP_KERNEL);
+	if (!dev)
+		return -ENODEV;
+
+	skb = alloc_skb(cfsiz + sizeof(struct can_skb_priv), gfp_any());
+	if (!skb)
+		goto lin_out;
+
+	can_skb_reserve(skb);
+	can_skb_prv(skb)->ifindex = dev->ifindex;
+	can_skb_prv(skb)->skbcnt = 0;
+	skb_put_data(skb, &cf, cfsiz);
+
+	skb->dev = dev;
+	can_skb_set_owner(skb, sk);
+	ret = can_send(skb, 1); /* send with loopback */
+
+lin_out:
+	netdev_put(dev, &tracker);
+	return ret;
+}
+
 /*
  * bcm_sendmsg - process BCM commands (opcodes) from the userspace
  */
@@ -1429,12 +1483,30 @@  static int bcm_sendmsg(struct socket *sock, struct msghdr *msg, size_t size)
 
 	case TX_SEND:
 		/* we need exactly one CAN frame behind the msg head */
-		if ((msg_head.nframes != 1) || (size != cfsiz + MHSIZ))
+		if (msg_head.nframes != 1 || size != cfsiz + MHSIZ)
 			ret = -EINVAL;
 		else
 			ret = bcm_tx_send(msg, ifindex, sk, cfsiz);
 		break;
 
+	case RX_LIN_SETUP:
+		/* we need exactly one CAN frame behind the msg head */
+		if (msg_head.nframes != 1 || size != cfsiz + MHSIZ)
+			ret = -EINVAL;
+		else
+			ret = bcm_lin_setup(&msg_head, msg, ifindex, sk, cfsiz,
+					    1);
+		break;
+
+	case RX_LIN_DELETE:
+		/* we need exactly one CAN frame behind the msg head */
+		if (msg_head.nframes != 1 || size != cfsiz + MHSIZ)
+			ret = -EINVAL;
+		else
+			ret = bcm_lin_setup(&msg_head, msg, ifindex, sk, cfsiz,
+					    0);
+		break;
+
 	default:
 		ret = -EINVAL;
 		break;