Commit f3dd3f47 authored by stephen hemminger's avatar stephen hemminger Committed by David S. Miller

vmbus: introduce in-place packet iterator

This is mostly just a refactoring of previous functions
(get_pkt_next_raw, put_pkt_raw and commit_rd_index) to make it easier
to use for other drivers and NAPI.
Signed-off-by: default avatarStephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 50698d80
......@@ -32,6 +32,8 @@
#include "hyperv_vmbus.h"
#define VMBUS_PKT_TRAILER 8
/*
* When we write to the ring buffer, check if the host needs to
* be signaled. Here is the details of this protocol:
......@@ -336,6 +338,12 @@ int hv_ringbuffer_write(struct vmbus_channel *channel,
return 0;
}
static inline void
init_cached_read_index(struct hv_ring_buffer_info *rbi)
{
rbi->cached_read_index = rbi->ring_buffer->read_index;
}
int hv_ringbuffer_read(struct vmbus_channel *channel,
void *buffer, u32 buflen, u32 *buffer_actual_len,
u64 *requestid, bool raw)
......@@ -366,7 +374,8 @@ int hv_ringbuffer_read(struct vmbus_channel *channel,
return ret;
}
init_cached_read_index(channel);
init_cached_read_index(inring_info);
next_read_location = hv_get_next_read_location(inring_info);
next_read_location = hv_copyfrom_ringbuffer(inring_info, &desc,
sizeof(desc),
......@@ -410,3 +419,86 @@ int hv_ringbuffer_read(struct vmbus_channel *channel,
return ret;
}
/*
* Determine number of bytes available in ring buffer after
* the current iterator (priv_read_index) location.
*
* This is similar to hv_get_bytes_to_read but with private
* read index instead.
*/
static u32 hv_pkt_iter_avail(const struct hv_ring_buffer_info *rbi)
{
u32 priv_read_loc = rbi->priv_read_index;
u32 write_loc = READ_ONCE(rbi->ring_buffer->write_index);
if (write_loc >= priv_read_loc)
return write_loc - priv_read_loc;
else
return (rbi->ring_datasize - priv_read_loc) + write_loc;
}
/*
* Get first vmbus packet from ring buffer after read_index
*
* If ring buffer is empty, returns NULL and no other action needed.
*/
struct vmpacket_descriptor *hv_pkt_iter_first(struct vmbus_channel *channel)
{
struct hv_ring_buffer_info *rbi = &channel->inbound;
/* set state for later hv_signal_on_read() */
init_cached_read_index(rbi);
if (hv_pkt_iter_avail(rbi) < sizeof(struct vmpacket_descriptor))
return NULL;
return hv_get_ring_buffer(rbi) + rbi->priv_read_index;
}
EXPORT_SYMBOL_GPL(hv_pkt_iter_first);
/*
* Get next vmbus packet from ring buffer.
*
* Advances the current location (priv_read_index) and checks for more
* data. If the end of the ring buffer is reached, then return NULL.
*/
struct vmpacket_descriptor *
__hv_pkt_iter_next(struct vmbus_channel *channel,
const struct vmpacket_descriptor *desc)
{
struct hv_ring_buffer_info *rbi = &channel->inbound;
u32 packetlen = desc->len8 << 3;
u32 dsize = rbi->ring_datasize;
/* bump offset to next potential packet */
rbi->priv_read_index += packetlen + VMBUS_PKT_TRAILER;
if (rbi->priv_read_index >= dsize)
rbi->priv_read_index -= dsize;
/* more data? */
if (hv_pkt_iter_avail(rbi) < sizeof(struct vmpacket_descriptor))
return NULL;
else
return hv_get_ring_buffer(rbi) + rbi->priv_read_index;
}
EXPORT_SYMBOL_GPL(__hv_pkt_iter_next);
/*
* Update host ring buffer after iterating over packets.
*/
void hv_pkt_iter_close(struct vmbus_channel *channel)
{
struct hv_ring_buffer_info *rbi = &channel->inbound;
/*
* Make sure all reads are done before we update the read index since
* the writer may start writing to the read area once the read index
* is updated.
*/
virt_rmb();
rbi->ring_buffer->read_index = rbi->priv_read_index;
hv_signal_on_read(channel);
}
EXPORT_SYMBOL_GPL(hv_pkt_iter_close);
......@@ -647,14 +647,11 @@ static void netvsc_send_tx_complete(struct netvsc_device *net_device,
static void netvsc_send_completion(struct netvsc_device *net_device,
struct vmbus_channel *incoming_channel,
struct hv_device *device,
struct vmpacket_descriptor *packet)
const struct vmpacket_descriptor *desc)
{
struct nvsp_message *nvsp_packet;
struct nvsp_message *nvsp_packet = hv_pkt_data(desc);
struct net_device *ndev = hv_get_drvdata(device);
nvsp_packet = (struct nvsp_message *)((unsigned long)packet +
(packet->offset8 << 3));
switch (nvsp_packet->hdr.msg_type) {
case NVSP_MSG_TYPE_INIT_COMPLETE:
case NVSP_MSG1_TYPE_SEND_RECV_BUF_COMPLETE:
......@@ -668,7 +665,7 @@ static void netvsc_send_completion(struct netvsc_device *net_device,
case NVSP_MSG1_TYPE_SEND_RNDIS_PKT_COMPLETE:
netvsc_send_tx_complete(net_device, incoming_channel,
device, packet);
device, desc);
break;
default:
......@@ -1071,9 +1068,11 @@ static void netvsc_receive(struct net_device *ndev,
struct net_device_context *net_device_ctx,
struct hv_device *device,
struct vmbus_channel *channel,
struct vmtransfer_page_packet_header *vmxferpage_packet,
const struct vmpacket_descriptor *desc,
struct nvsp_message *nvsp)
{
const struct vmtransfer_page_packet_header *vmxferpage_packet
= container_of(desc, const struct vmtransfer_page_packet_header, d);
char *recv_buf = net_device->recv_buf;
u32 status = NVSP_STAT_SUCCESS;
int i;
......@@ -1185,12 +1184,10 @@ static void netvsc_process_raw_pkt(struct hv_device *device,
struct netvsc_device *net_device,
struct net_device *ndev,
u64 request_id,
struct vmpacket_descriptor *desc)
const struct vmpacket_descriptor *desc)
{
struct net_device_context *net_device_ctx = netdev_priv(ndev);
struct nvsp_message *nvmsg
= (struct nvsp_message *)((unsigned long)desc
+ (desc->offset8 << 3));
struct nvsp_message *nvmsg = hv_pkt_data(desc);
switch (desc->type) {
case VM_PKT_COMP:
......@@ -1199,9 +1196,7 @@ static void netvsc_process_raw_pkt(struct hv_device *device,
case VM_PKT_DATA_USING_XFER_PAGES:
netvsc_receive(ndev, net_device, net_device_ctx,
device, channel,
(struct vmtransfer_page_packet_header *)desc,
nvmsg);
device, channel, desc, nvmsg);
break;
case VM_PKT_DATA_INBAND:
......@@ -1223,7 +1218,6 @@ void netvsc_channel_cb(void *context)
struct netvsc_device *net_device;
struct vmpacket_descriptor *desc;
struct net_device *ndev;
bool need_to_commit = false;
if (channel->primary_channel != NULL)
device = channel->primary_channel->device_obj;
......@@ -1239,20 +1233,12 @@ void netvsc_channel_cb(void *context)
netvsc_channel_idle(net_device, q_idx))
return;
/* commit_rd_index() -> hv_signal_on_read() needs this. */
init_cached_read_index(channel);
while ((desc = get_next_pkt_raw(channel)) != NULL) {
foreach_vmbus_pkt(desc, channel) {
netvsc_process_raw_pkt(device, channel, net_device,
ndev, desc->trans_id, desc);
put_pkt_raw(channel, desc);
need_to_commit = true;
}
if (need_to_commit)
commit_rd_index(channel);
netvsc_chk_recv_comp(net_device, channel, q_idx);
}
......
......@@ -1504,14 +1504,6 @@ static inline void hv_signal_on_read(struct vmbus_channel *channel)
return;
}
static inline void
init_cached_read_index(struct vmbus_channel *channel)
{
struct hv_ring_buffer_info *rbi = &channel->inbound;
rbi->cached_read_index = rbi->ring_buffer->read_index;
}
/*
* Mask off host interrupt callback notifications
*/
......@@ -1545,76 +1537,48 @@ static inline u32 hv_end_read(struct hv_ring_buffer_info *rbi)
/*
* An API to support in-place processing of incoming VMBUS packets.
*/
#define VMBUS_PKT_TRAILER 8
static inline struct vmpacket_descriptor *
get_next_pkt_raw(struct vmbus_channel *channel)
/* Get data payload associated with descriptor */
static inline void *hv_pkt_data(const struct vmpacket_descriptor *desc)
{
struct hv_ring_buffer_info *ring_info = &channel->inbound;
u32 priv_read_loc = ring_info->priv_read_index;
void *ring_buffer = hv_get_ring_buffer(ring_info);
u32 dsize = ring_info->ring_datasize;
/*
* delta is the difference between what is available to read and
* what was already consumed in place. We commit read index after
* the whole batch is processed.
*/
u32 delta = priv_read_loc >= ring_info->ring_buffer->read_index ?
priv_read_loc - ring_info->ring_buffer->read_index :
(dsize - ring_info->ring_buffer->read_index) + priv_read_loc;
u32 bytes_avail_toread = (hv_get_bytes_to_read(ring_info) - delta);
if (bytes_avail_toread < sizeof(struct vmpacket_descriptor))
return NULL;
return ring_buffer + priv_read_loc;
return (void *)((unsigned long)desc + (desc->offset8 << 3));
}
/*
* A helper function to step through packets "in-place"
* This API is to be called after each successful call
* get_next_pkt_raw().
*/
static inline void put_pkt_raw(struct vmbus_channel *channel,
struct vmpacket_descriptor *desc)
/* Get data size associated with descriptor */
static inline u32 hv_pkt_datalen(const struct vmpacket_descriptor *desc)
{
struct hv_ring_buffer_info *ring_info = &channel->inbound;
u32 packetlen = desc->len8 << 3;
u32 dsize = ring_info->ring_datasize;
/*
* Include the packet trailer.
*/
ring_info->priv_read_index += packetlen + VMBUS_PKT_TRAILER;
ring_info->priv_read_index %= dsize;
return (desc->len8 << 3) - (desc->offset8 << 3);
}
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);
void hv_pkt_iter_close(struct vmbus_channel *channel);
/*
* This call commits the read index and potentially signals the host.
* Here is the pattern for using the "in-place" consumption APIs:
*
* init_cached_read_index();
*
* while (get_next_pkt_raw() {
* process the packet "in-place";
* put_pkt_raw();
* }
* if (packets processed in place)
* commit_rd_index();
* Get next packet descriptor from iterator
* If at end of list, return NULL and update host.
*/
static inline void commit_rd_index(struct vmbus_channel *channel)
static inline struct vmpacket_descriptor *
hv_pkt_iter_next(struct vmbus_channel *channel,
const struct vmpacket_descriptor *pkt)
{
struct hv_ring_buffer_info *ring_info = &channel->inbound;
/*
* Make sure all reads are done before we update the read index since
* the writer may start writing to the read area once the read index
* is updated.
*/
virt_rmb();
ring_info->ring_buffer->read_index = ring_info->priv_read_index;
struct vmpacket_descriptor *nxt;
nxt = __hv_pkt_iter_next(channel, pkt);
if (!nxt)
hv_pkt_iter_close(channel);
hv_signal_on_read(channel);
return nxt;
}
#define foreach_vmbus_pkt(pkt, channel) \
for (pkt = hv_pkt_iter_first(channel); pkt; \
pkt = hv_pkt_iter_next(channel, pkt))
#endif /* _HYPERV_H */
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