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: Stephen Hemminger <sthemmin@microsoft.com> Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
stephen hemminger
David S. Miller
parent
50698d80f8
commit
f3dd3f4797
|
|
@ -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
|
||||
|
||||
/* Get data payload associated with descriptor */
|
||||
static inline void *hv_pkt_data(const struct vmpacket_descriptor *desc)
|
||||
{
|
||||
return (void *)((unsigned long)desc + (desc->offset8 << 3));
|
||||
}
|
||||
|
||||
/* Get data size associated with descriptor */
|
||||
static inline u32 hv_pkt_datalen(const struct vmpacket_descriptor *desc)
|
||||
{
|
||||
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);
|
||||
|
||||
/*
|
||||
* Get next packet descriptor from iterator
|
||||
* If at end of list, return NULL and update host.
|
||||
*/
|
||||
static inline struct vmpacket_descriptor *
|
||||
get_next_pkt_raw(struct vmbus_channel *channel)
|
||||
hv_pkt_iter_next(struct vmbus_channel *channel,
|
||||
const struct vmpacket_descriptor *pkt)
|
||||
{
|
||||
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);
|
||||
struct vmpacket_descriptor *nxt;
|
||||
|
||||
if (bytes_avail_toread < sizeof(struct vmpacket_descriptor))
|
||||
return NULL;
|
||||
nxt = __hv_pkt_iter_next(channel, pkt);
|
||||
if (!nxt)
|
||||
hv_pkt_iter_close(channel);
|
||||
|
||||
return ring_buffer + priv_read_loc;
|
||||
}
|
||||
|
||||
/*
|
||||
* 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)
|
||||
{
|
||||
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;
|
||||
}
|
||||
|
||||
/*
|
||||
* 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();
|
||||
*/
|
||||
static inline void commit_rd_index(struct vmbus_channel *channel)
|
||||
{
|
||||
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;
|
||||
|
||||
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 */
|
||||
|
|
|
|||
Loading…
Reference in a new issue