diff options
Diffstat (limited to 'net')
| -rw-r--r-- | net/can/af_can.c | 63 | ||||
| -rw-r--r-- | net/can/bcm.c | 7 |
2 files changed, 52 insertions, 18 deletions
diff --git a/net/can/af_can.c b/net/can/af_can.c index 7d4d2b3..d8173e5 100644 --- a/net/can/af_can.c +++ b/net/can/af_can.c @@ -319,23 +319,52 @@ static struct dev_rcv_lists *find_dev_rcv_lists(struct net_device *dev) return n ? d : NULL; } +/** + * 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 + * @d: pointer to the device filter struct + * + * Description: + * Returns the optimal filterlist to reduce the filter handling in the + * receive path. This function is called by service functions that need + * to register or unregister a can_filter in the filter lists. + * + * A filter matches in general, when + * + * <received_can_id> & mask == can_id & mask + * + * so every bit set in the mask (even CAN_EFF_FLAG, CAN_RTR_FLAG) describe + * relevant bits for the filter. + * + * The filter can be inverted (CAN_INV_FILTER bit set in can_id) or it can + * filter for error frames (CAN_ERR_FLAG bit set in mask). For error frames + * there is a special filterlist and a special rx path filter handling. + * + * Return: + * Pointer to optimal filterlist for the given can_id/mask pair. + * Constistency checked mask. + * Reduced can_id to have a preprocessed filter compare value. + */ static struct hlist_head *find_rcv_list(canid_t *can_id, canid_t *mask, struct dev_rcv_lists *d) { canid_t inv = *can_id & CAN_INV_FILTER; /* save flag before masking */ - /* filter error frames */ + /* filter for error frames in extra filterlist */ if (*mask & CAN_ERR_FLAG) { - /* clear CAN_ERR_FLAG in list entry */ + /* clear CAN_ERR_FLAG in filter entry */ *mask &= CAN_ERR_MASK; return &d->rx[RX_ERR]; } - /* ensure valid values in can_mask */ - if (*mask & CAN_EFF_FLAG) - *mask &= (CAN_EFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG); - else - *mask &= (CAN_SFF_MASK | CAN_RTR_FLAG); + /* with cleared CAN_ERR_FLAG we have a simple mask/value filterpair */ + +#define CAN_EFF_RTR_FLAGS (CAN_EFF_FLAG | CAN_RTR_FLAG) + + /* ensure valid values in can_mask for 'SFF only' frame filtering */ + if ((*mask & CAN_EFF_FLAG) && !(*can_id & CAN_EFF_FLAG)) + *mask &= (CAN_SFF_MASK | CAN_EFF_RTR_FLAGS); /* reduce condition testing at receive time */ *can_id &= *mask; @@ -348,15 +377,19 @@ static struct hlist_head *find_rcv_list(canid_t *can_id, canid_t *mask, if (!(*mask)) return &d->rx[RX_ALL]; - /* use extra filterset for the subscription of exactly *ONE* can_id */ - if (*can_id & CAN_EFF_FLAG) { - if (*mask == (CAN_EFF_MASK | CAN_EFF_FLAG)) { - /* RFC: a use-case for hash-tables in the future? */ - return &d->rx[RX_EFF]; + /* extra filterlists for the subscription of a single non-RTR can_id */ + if (((*mask & CAN_EFF_RTR_FLAGS) == CAN_EFF_RTR_FLAGS) + && !(*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]; + } + } else { + if (*mask == (CAN_SFF_MASK | CAN_EFF_RTR_FLAGS)) + return &d->rx_sff[*can_id]; } - } else { - if (*mask == CAN_SFF_MASK) - return &d->rx_sff[*can_id]; } /* default: filter via can_id/can_mask */ diff --git a/net/can/bcm.c b/net/can/bcm.c index d0dd382..da0d426 100644 --- a/net/can/bcm.c +++ b/net/can/bcm.c @@ -64,10 +64,11 @@ #define BCM_CAN_DLC_MASK 0x0F /* clean private flags in can_dlc by masking */ /* get best masking value for can_rx_register() for a given single can_id */ -#define REGMASK(id) ((id & CAN_RTR_FLAG) | ((id & CAN_EFF_FLAG) ? \ - (CAN_EFF_MASK | CAN_EFF_FLAG) : CAN_SFF_MASK)) +#define REGMASK(id) ((id & CAN_EFF_FLAG) ? \ + (CAN_EFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG) : \ + (CAN_SFF_MASK | CAN_EFF_FLAG | CAN_RTR_FLAG)) -#define CAN_BCM_VERSION "20080415" +#define CAN_BCM_VERSION CAN_VERSION static __initdata const char banner[] = KERN_INFO "can: broadcast manager protocol (rev " CAN_BCM_VERSION ")\n"; |
