On Fri, 05 Jan 2018 15:24:48 +0100 Thomas Monjalon <tho...@monjalon.net> wrote:
> Stephen, > Qiming was suggesting a name change for the functions. > What do you think? > > 13/10/2017 17:12, Stephen Hemminger: > > On Wed, 11 Oct 2017 08:32:12 +0000 > > "Yang, Qiming" <qiming.y...@intel.com> wrote: > > > > > > From: dev [mailto:dev-boun...@dpdk.org] On Behalf Of Stephen Hemminger > > > > Sent: Saturday, July 15, 2017 2:30 AM > > > > To: dev@dpdk.org > > > > Cc: Stephen Hemminger <step...@networkplumber.org>; Stephen Hemminger > > > > <sthem...@microsoft.com> > > > > Subject: [dpdk-dev] [RFC 01/14] ethdev: add link status read/write > > > > functions > > > > > > > > Many drivers are all doing copy/paste of the same code to atomicly > > > > update the > > > > link status. Reduce duplication, and allow for future changes by having > > > > common > > > > function for this. > > > > > > > > Signed-off-by: Stephen Hemminger <sthem...@microsoft.com> > > > > --- > > > > lib/librte_ether/rte_ethdev.c | 36 ++++++++++++++++++++++++++++++++++++ > > > > lib/librte_ether/rte_ethdev.h | 28 ++++++++++++++++++++++++++++ > > > > 2 files changed, 64 insertions(+) > > > > > > > > diff --git a/lib/librte_ether/rte_ethdev.c > > > > b/lib/librte_ether/rte_ethdev.c index > > > > a1b744704f3a..7532fc6b65f0 100644 > > > > --- a/lib/librte_ether/rte_ethdev.c > > > > +++ b/lib/librte_ether/rte_ethdev.c > > > > @@ -1332,6 +1332,42 @@ rte_eth_link_get_nowait(uint8_t port_id, struct > > > > rte_eth_link *eth_link) } > > > > > > > > int > > > > +_rte_eth_link_update(struct rte_eth_dev *dev, > > > > + const struct rte_eth_link *link) > > > > +{ > > > > + volatile struct rte_eth_link *dev_link = &(dev->data->dev_link); > > > > + struct rte_eth_link old; > > > > + > > > > + RTE_BUILD_BUG_ON(sizeof(*link) != sizeof(uint64_t)); > > > > + > > > > + old = *dev_link; > > > > + > > > > + /* Only reason we use cmpset rather than set is > > > > + * that on some architecture may use sign bit as a flag value. > > > > + */ > > > > + while (rte_atomic64_cmpset((volatile uint64_t *)dev_link, > > > > + *(volatile uint64_t *)dev_link, > > > > + *(const uint64_t *)link) == 0) > > > > + continue; > > > > + > > > > + return (old.link_status == link->link_status) ? -1 : 0; } > > > > + > > > > +void _rte_eth_link_read(struct rte_eth_dev *dev, > > > > + struct rte_eth_link *link) > > > > +{ > > > > + const uint64_t *src = (const uint64_t *)&(dev->data->dev_link); > > > > + volatile uint64_t *dst = (uint64_t *)link; > > > > + > > > > + RTE_BUILD_BUG_ON(sizeof(*link) != sizeof(uint64_t)); > > > > + > > > > + /* Note: this should never fail since both destination and > > > > expected > > > > + * values are the same and are a pointer from caller. > > > > + */ > > > > + rte_atomic64_cmpset(dst, *dst, *src); > > > > +} > > > > + > > > > +int > > > > rte_eth_stats_get(uint8_t port_id, struct rte_eth_stats *stats) { > > > > struct rte_eth_dev *dev; > > > > diff --git a/lib/librte_ether/rte_ethdev.h > > > > b/lib/librte_ether/rte_ethdev.h index > > > > f6837278521c..974657933f23 100644 > > > > --- a/lib/librte_ether/rte_ethdev.h > > > > +++ b/lib/librte_ether/rte_ethdev.h > > > > @@ -2219,6 +2219,34 @@ void rte_eth_link_get(uint8_t port_id, struct > > > > rte_eth_link *link); > > > > */ > > > > void rte_eth_link_get_nowait(uint8_t port_id, struct rte_eth_link > > > > *link); > > > > > > > > + > > > > +/** > > > > + * @internal > > > > + * Atomically write the link status for the specific device. > > > > + * It is for use by DPDK device driver use only. > > > > + * User applications should not call it > > > > + * > > > > + * @param dev > > > > + * Pointer to struct rte_eth_dev. > > > > + * @param link > > > > + * New link status value. > > > > + * @return > > > > + * -1 if link state has changed, 0 if the same. > > > > + */ > > > > +int _rte_eth_link_update(struct rte_eth_dev *dev, > > > > + const struct rte_eth_link *link); > > > > + > > > This function is only do the atomically write, what do you think to > > > change the function name to _rte_eth_atomic_write_link_status, > > > Use name link_update makes me confused, and mix up it with dev_ops > > > link_update. > > > > +/** > > > > + * @internal > > > > + * Atomically read the link speed and status. > > > > + * @param dev > > > > + * Pointer to struct rte_eth_dev. > > > > + * @param link > > > > + * link status value. > > > > + */ > > > > +void _rte_eth_link_read(struct rte_eth_dev *dev, > > > > + struct rte_eth_link *link); > > > > + > > > This name is also not very clear. I think change to > > > _rte_eth_atomic_read_link_status will better. > > > > /** > > > > * Retrieve the general I/O statistics of an Ethernet device. > > > > * > > > > -- > > > > 2.11.0 > > > > > > > The first set of patches was just trying to combine multiple copies of > > same code. > > Every place was doing same thing for atomic update. I would just change the name to linkstatsus update. Also since writes of unsigned long are guaranteed atomic, the code could be optimized on 64bit platforms.
