Michael Kelley (LINUX)
2022-Apr-20 23:15 UTC
[PATCH 5/5] Drivers: hv: vmbus: Refactor the ring-buffer iterator functions
From: Andrea Parri (Microsoft) <parri.andrea at gmail.com> Sent: Wednesday, April 20, 2022 1:07 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 | 32 +++++++++----------------------- > include/linux/hyperv.h | 35 ++++------------------------------- > 2 files changed, 13 insertions(+), 54 deletions(-) > > diff --git a/drivers/hv/ring_buffer.c b/drivers/hv/ring_buffer.c > index 3d215d9dec433..fa98b3a91206a 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); > @@ -456,22 +456,6 @@ static u32 hv_pkt_iter_avail(const struct hv_ring_buffer_info > *rbi) > return (rbi->ring_datasize - priv_read_loc) + write_loc; > } > > -/* > - * Get first vmbus packet without copying it out of the ring buffer > - */ > -struct vmpacket_descriptor *hv_pkt_iter_first_raw(struct vmbus_channel *channel) > -{ > - struct hv_ring_buffer_info *rbi = &channel->inbound; > - > - hv_debug_delay_test(channel, MESSAGE_DELAY); > - > - if (hv_pkt_iter_avail(rbi) < sizeof(struct vmpacket_descriptor)) > - return NULL; > - > - return (struct vmpacket_descriptor *)(hv_get_ring_buffer(rbi) + rbi- > >priv_read_index); > -} > -EXPORT_SYMBOL_GPL(hv_pkt_iter_first_raw); > - > /* > * Get first vmbus packet from ring buffer after read_index > * > @@ -483,11 +467,14 @@ struct vmpacket_descriptor *hv_pkt_iter_first(struct > vmbus_channel *channel) > struct vmpacket_descriptor *desc, *desc_copy; > u32 bytes_avail, pkt_len, pkt_offset; > > - desc = hv_pkt_iter_first_raw(channel); > - if (!desc) > + hv_debug_delay_test(channel, MESSAGE_DELAY); > + > + bytes_avail = hv_pkt_iter_avail(rbi); > + if (bytes_avail < sizeof(struct vmpacket_descriptor)) > return NULL; > + bytes_avail = min(rbi->pkt_buffer_size, bytes_avail); > > - bytes_avail = min(rbi->pkt_buffer_size, hv_pkt_iter_avail(rbi)); > + desc = (struct vmpacket_descriptor *)(hv_get_ring_buffer(rbi) + rbi- > >priv_read_index); > > /* > * Ensure the compiler does not use references to incoming Hyper-V values > (which > @@ -534,8 +521,7 @@ 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 +534,7 @@ __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)) > -- > 2.25.1Reviewed-by: Michael Kelley <mikelley at microsoft.com>