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-rw-r--r--net/can/af_can.c31
-rw-r--r--net/can/af_can.h5
-rw-r--r--net/can/proc.c48
3 files changed, 75 insertions, 9 deletions
diff --git a/net/can/af_can.c b/net/can/af_can.c
index a27f8aad9e99..ce82337521f6 100644
--- a/net/can/af_can.c
+++ b/net/can/af_can.c
@@ -338,6 +338,29 @@ static struct dev_rcv_lists *find_dev_rcv_lists(struct net_device *dev)
}
/**
+ * 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
* @mask: pointer to CAN mask 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++;
diff --git a/net/can/af_can.h b/net/can/af_can.h
index b4bdaa32d7a4..fca0fe9fc45a 100644
--- a/net/can/af_can.h
+++ b/net/can/af_can.h
@@ -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;
};
diff --git a/net/can/proc.c b/net/can/proc.c
index 1621e5909ee6..1a19b985a868 100644
--- a/net/can/proc.c
+++ b/net/can/proc.c
@@ -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);
}