Michael Kelley (LINUX)
2022-Apr-15 03:34 UTC
[RFC PATCH 6/6] Drivers: hv: vmbus: Refactor the ring-buffer iterator functions
From: Andrea Parri (Microsoft) <parri.andrea at gmail.com> Sent: Wednesday, April 13, 2022 1:48 PM> > With no users of hv_pkt_iter_next_raw() and no "external" users of > hv_pkt_iter_first_raw(), the iterator functions can be refactored > and simplified to remove some indirection/code. > > Signed-off-by: Andrea Parri (Microsoft) <parri.andrea at gmail.com> > --- > drivers/hv/ring_buffer.c | 11 +++++------ > include/linux/hyperv.h | 35 ++++------------------------------- > 2 files changed, 9 insertions(+), 37 deletions(-) > > diff --git a/drivers/hv/ring_buffer.c b/drivers/hv/ring_buffer.c > index 3d215d9dec433..c9357dae2a2c8 100644 > --- a/drivers/hv/ring_buffer.c > +++ b/drivers/hv/ring_buffer.c > @@ -421,7 +421,7 @@ int hv_ringbuffer_read(struct vmbus_channel *channel, > memcpy(buffer, (const char *)desc + offset, packetlen); > > /* Advance ring index to next packet descriptor */ > - __hv_pkt_iter_next(channel, desc, true); > + __hv_pkt_iter_next(channel, desc); > > /* Notify host of update */ > hv_pkt_iter_close(channel); > @@ -459,7 +459,8 @@ static u32 hv_pkt_iter_avail(const struct hv_ring_buffer_info > *rbi) > /* > * Get first vmbus packet without copying it out of the ring buffer > */ > -struct vmpacket_descriptor *hv_pkt_iter_first_raw(struct vmbus_channel *channel) > +static struct vmpacket_descriptor * > +hv_pkt_iter_first_raw(struct vmbus_channel *channel) > { > struct hv_ring_buffer_info *rbi = &channel->inbound; > > @@ -470,7 +471,6 @@ struct vmpacket_descriptor *hv_pkt_iter_first_raw(struct > vmbus_channel *channel) > > return (struct vmpacket_descriptor *)(hv_get_ring_buffer(rbi) + rbi- > >priv_read_index); > } > -EXPORT_SYMBOL_GPL(hv_pkt_iter_first_raw);Does hv_pkt_iter_first_raw() need to be retained at all as a separate function? I think after these changes, the only caller is hv_pkt_iter_first(), in which case the code could just go inline in hv_pkt_iter_first(). Doing that combining would also allow the elimination of the duplicate call to hv_pkt_iter_avail(). Michael> > /* > * Get first vmbus packet from ring buffer after read_index > @@ -534,8 +534,7 @@ EXPORT_SYMBOL_GPL(hv_pkt_iter_first); > */ > struct vmpacket_descriptor * > __hv_pkt_iter_next(struct vmbus_channel *channel, > - const struct vmpacket_descriptor *desc, > - bool copy) > + const struct vmpacket_descriptor *desc) > { > struct hv_ring_buffer_info *rbi = &channel->inbound; > u32 packetlen = desc->len8 << 3; > @@ -548,7 +547,7 @@ __hv_pkt_iter_next(struct vmbus_channel *channel, > rbi->priv_read_index -= dsize; > > /* more data? */ > - return copy ? hv_pkt_iter_first(channel) : hv_pkt_iter_first_raw(channel); > + return hv_pkt_iter_first(channel); > } > EXPORT_SYMBOL_GPL(__hv_pkt_iter_next); > > diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h > index 1112c5cf894e6..370adc9971d3e 100644 > --- a/include/linux/hyperv.h > +++ b/include/linux/hyperv.h > @@ -1673,55 +1673,28 @@ static inline u32 hv_pkt_len(const struct > vmpacket_descriptor *desc) > return desc->len8 << 3; > } > > -struct vmpacket_descriptor * > -hv_pkt_iter_first_raw(struct vmbus_channel *channel); > - > struct vmpacket_descriptor * > hv_pkt_iter_first(struct vmbus_channel *channel); > > struct vmpacket_descriptor * > __hv_pkt_iter_next(struct vmbus_channel *channel, > - const struct vmpacket_descriptor *pkt, > - bool copy); > + const struct vmpacket_descriptor *pkt); > > void hv_pkt_iter_close(struct vmbus_channel *channel); > > static inline struct vmpacket_descriptor * > -hv_pkt_iter_next_pkt(struct vmbus_channel *channel, > - const struct vmpacket_descriptor *pkt, > - bool copy) > +hv_pkt_iter_next(struct vmbus_channel *channel, > + const struct vmpacket_descriptor *pkt) > { > struct vmpacket_descriptor *nxt; > > - nxt = __hv_pkt_iter_next(channel, pkt, copy); > + nxt = __hv_pkt_iter_next(channel, pkt); > if (!nxt) > hv_pkt_iter_close(channel); > > return nxt; > } > > -/* > - * Get next packet descriptor without copying it out of the ring buffer > - * If at end of list, return NULL and update host. > - */ > -static inline struct vmpacket_descriptor * > -hv_pkt_iter_next_raw(struct vmbus_channel *channel, > - const struct vmpacket_descriptor *pkt) > -{ > - return hv_pkt_iter_next_pkt(channel, pkt, false); > -} > - > -/* > - * Get next packet descriptor from iterator > - * If at end of list, return NULL and update host. > - */ > -static inline struct vmpacket_descriptor * > -hv_pkt_iter_next(struct vmbus_channel *channel, > - const struct vmpacket_descriptor *pkt) > -{ > - return hv_pkt_iter_next_pkt(channel, pkt, true); > -} > - > #define foreach_vmbus_pkt(pkt, channel) \ > for (pkt = hv_pkt_iter_first(channel); pkt; \ > pkt = hv_pkt_iter_next(channel, pkt)) > -- > 2.25.1