can: add hash based access to single EFF frame filters (45c70029) · Commits · 戴 / test

net/can/af_can.c

+26 −5

Original line number	Diff line number	Diff line
		@@ -337,6 +337,29 @@ static struct dev_rcv_lists find_dev_rcv_lists(struct net_device dev)
		return (struct dev_rcv_lists *)dev->ml_priv;
		}

		/**
		* effhash - hash function for 29 bit CAN identifier reduction
		* @can_id: 29 bit CAN identifier
		*
		* Description:
		* To reduce the linear traversal in one linked list of _single_ EFF CAN
		* frame subscriptions the 29 bit identifier is mapped to 10 bits.
		* (see CAN_EFF_RCV_HASH_BITS definition)
		*
		* Return:
		* Hash value from 0x000 - 0x3FF ( enforced by CAN_EFF_RCV_HASH_BITS mask )
		*/
		static unsigned int effhash(canid_t can_id)
		{
		unsigned int hash;

		hash = can_id;
		hash ^= can_id >> CAN_EFF_RCV_HASH_BITS;
		hash ^= can_id >> (2 * CAN_EFF_RCV_HASH_BITS);

		return hash & ((1 << CAN_EFF_RCV_HASH_BITS) - 1);
		}

		/**
		* find_rcv_list - determine optimal filterlist inside device filter struct
		* @can_id: pointer to CAN identifier of a given can_filter
		@@ -400,10 +423,8 @@ static struct hlist_head find_rcv_list(canid_t can_id, canid_t *mask,
		!(*can_id & CAN_RTR_FLAG)) {

		if (*can_id & CAN_EFF_FLAG) {
		if (*mask == (CAN_EFF_MASK \| CAN_EFF_RTR_FLAGS)) {
		/* RFC: a future use-case for hash-tables? */
		return &d->rx[RX_EFF];
		}
		if (*mask == (CAN_EFF_MASK \| CAN_EFF_RTR_FLAGS))
		return &d->rx_eff[effhash(*can_id)];
		} else {
		if (*mask == (CAN_SFF_MASK \| CAN_EFF_RTR_FLAGS))
		return &d->rx_sff[*can_id];
		@@ -632,7 +653,7 @@ static int can_rcv_filter(struct dev_rcv_lists d, struct sk_buff skb)
		return matches;

		if (can_id & CAN_EFF_FLAG) {
		hlist_for_each_entry_rcu(r, &d->rx[RX_EFF], list) {
		hlist_for_each_entry_rcu(r, &d->rx_eff[effhash(can_id)], list) {
		if (r->can_id == can_id) {
		deliver(skb, r);
		matches++;

net/can/af_can.h

+4 −1

Original line number	Diff line number	Diff line
		@@ -60,13 +60,16 @@ struct receiver {
		};

		#define CAN_SFF_RCV_ARRAY_SZ (1 << CAN_SFF_ID_BITS)
		#define CAN_EFF_RCV_HASH_BITS 10
		#define CAN_EFF_RCV_ARRAY_SZ (1 << CAN_EFF_RCV_HASH_BITS)

		enum { RX_ERR, RX_ALL, RX_FIL, RX_INV, RX_EFF, RX_MAX };
		enum { RX_ERR, RX_ALL, RX_FIL, RX_INV, RX_MAX };

		/* per device receive filters linked at dev->ml_priv */
		struct dev_rcv_lists {
		struct hlist_head rx[RX_MAX];
		struct hlist_head rx_sff[CAN_SFF_RCV_ARRAY_SZ];
		struct hlist_head rx_eff[CAN_EFF_RCV_ARRAY_SZ];
		int remove_on_zero_entries;
		int entries;
		};

net/can/proc.c

+45 −3

Original line number	Diff line number	Diff line
		@@ -80,7 +80,6 @@ static const char rx_list_name[][8] = {
		[RX_ALL] = "rx_all",
		[RX_FIL] = "rx_fil",
		[RX_INV] = "rx_inv",
		[RX_EFF] = "rx_eff",
		};

		/*
		@@ -456,6 +455,49 @@ static const struct file_operations can_rcvlist_sff_proc_fops = {
		.release = single_release,
		};


		static int can_rcvlist_eff_proc_show(struct seq_file m, void v)
		{
		struct net_device *dev;
		struct dev_rcv_lists *d;

		/* RX_EFF */
		seq_puts(m, "\nreceive list 'rx_eff':\n");

		rcu_read_lock();

		/* eff receive list for 'all' CAN devices (dev == NULL) */
		d = &can_rx_alldev_list;
		can_rcvlist_proc_show_array(m, NULL, d->rx_eff, ARRAY_SIZE(d->rx_eff));

		/* eff receive list for registered CAN devices */
		for_each_netdev_rcu(&init_net, dev) {
		if (dev->type == ARPHRD_CAN && dev->ml_priv) {
		d = dev->ml_priv;
		can_rcvlist_proc_show_array(m, dev, d->rx_eff,
		ARRAY_SIZE(d->rx_eff));
		}
		}

		rcu_read_unlock();

		seq_putc(m, '\n');
		return 0;
		}

		static int can_rcvlist_eff_proc_open(struct inode inode, struct file file)
		{
		return single_open(file, can_rcvlist_eff_proc_show, NULL);
		}

		static const struct file_operations can_rcvlist_eff_proc_fops = {
		.owner = THIS_MODULE,
		.open = can_rcvlist_eff_proc_open,
		.read = seq_read,
		.llseek = seq_lseek,
		.release = single_release,
		};

		/*
		* proc utility functions
		*/
		@@ -495,8 +537,8 @@ void can_init_proc(void)
		&can_rcvlist_proc_fops, (void *)RX_FIL);
		pde_rcvlist_inv = proc_create_data(CAN_PROC_RCVLIST_INV, 0644, can_dir,
		&can_rcvlist_proc_fops, (void *)RX_INV);
		pde_rcvlist_eff = proc_create_data(CAN_PROC_RCVLIST_EFF, 0644, can_dir,
		&can_rcvlist_proc_fops, (void *)RX_EFF);
		pde_rcvlist_eff = proc_create(CAN_PROC_RCVLIST_EFF, 0644, can_dir,
		&can_rcvlist_eff_proc_fops);
		pde_rcvlist_sff = proc_create(CAN_PROC_RCVLIST_SFF, 0644, can_dir,
		&can_rcvlist_sff_proc_fops);
		}

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