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vmbus: split ring buffer allocation from open
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The UIO driver needs the ring buffer to be persistent(reused)
across open/close. Split the allocation and setup of ring buffer
out of vmbus_open. For normal usage vmbus_open/vmbus_close there
are no changes; only impacts uio_hv_generic which needs to keep
ring buffer memory and reuse when application restarts.

Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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@shemminger @gregkh
shemminger authored and gregkh committed Sep 25, 2018
1 parent 52a42c2 commit ae6935e
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Showing 3 changed files with 162 additions and 115 deletions.
267 changes: 152 additions & 115 deletions drivers/hv/channel.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -79,84 +79,96 @@ void vmbus_setevent(struct vmbus_channel *channel)
}
EXPORT_SYMBOL_GPL(vmbus_setevent);

/*
* vmbus_open - Open the specified channel.
*/
int vmbus_open(struct vmbus_channel *newchannel, u32 send_ringbuffer_size,
u32 recv_ringbuffer_size, void *userdata, u32 userdatalen,
void (*onchannelcallback)(void *context), void *context)
/* vmbus_free_ring - drop mapping of ring buffer */
void vmbus_free_ring(struct vmbus_channel *channel)
{
struct vmbus_channel_open_channel *open_msg;
struct vmbus_channel_msginfo *open_info = NULL;
unsigned long flags;
int ret, err = 0;
struct page *page;
unsigned int order;
hv_ringbuffer_cleanup(&channel->outbound);
hv_ringbuffer_cleanup(&channel->inbound);

if (send_ringbuffer_size % PAGE_SIZE ||
recv_ringbuffer_size % PAGE_SIZE)
return -EINVAL;
if (channel->ringbuffer_page) {
__free_pages(channel->ringbuffer_page,
get_order(channel->ringbuffer_pagecount
<< PAGE_SHIFT));
channel->ringbuffer_page = NULL;
}
}
EXPORT_SYMBOL_GPL(vmbus_free_ring);

order = get_order(send_ringbuffer_size + recv_ringbuffer_size);
/* vmbus_alloc_ring - allocate and map pages for ring buffer */
int vmbus_alloc_ring(struct vmbus_channel *newchannel,
u32 send_size, u32 recv_size)
{
struct page *page;
int order;

spin_lock_irqsave(&newchannel->lock, flags);
if (newchannel->state == CHANNEL_OPEN_STATE) {
newchannel->state = CHANNEL_OPENING_STATE;
} else {
spin_unlock_irqrestore(&newchannel->lock, flags);
if (send_size % PAGE_SIZE || recv_size % PAGE_SIZE)
return -EINVAL;
}
spin_unlock_irqrestore(&newchannel->lock, flags);

newchannel->onchannel_callback = onchannelcallback;
newchannel->channel_callback_context = context;

/* Allocate the ring buffer */
order = get_order(send_size + recv_size);
page = alloc_pages_node(cpu_to_node(newchannel->target_cpu),
GFP_KERNEL|__GFP_ZERO, order);

if (!page)
page = alloc_pages(GFP_KERNEL|__GFP_ZERO, order);

if (!page) {
err = -ENOMEM;
goto error_set_chnstate;
}
if (!page)
return -ENOMEM;

newchannel->ringbuffer_page = page;
newchannel->ringbuffer_pagecount = (send_ringbuffer_size +
recv_ringbuffer_size) >> PAGE_SHIFT;
newchannel->ringbuffer_pagecount = (send_size + recv_size) >> PAGE_SHIFT;
newchannel->ringbuffer_send_offset = send_size >> PAGE_SHIFT;

ret = hv_ringbuffer_init(&newchannel->outbound, page,
send_ringbuffer_size >> PAGE_SHIFT);
return 0;
}
EXPORT_SYMBOL_GPL(vmbus_alloc_ring);

if (ret != 0) {
err = ret;
goto error_free_pages;
}
static int __vmbus_open(struct vmbus_channel *newchannel,
void *userdata, u32 userdatalen,
void (*onchannelcallback)(void *context), void *context)
{
struct vmbus_channel_open_channel *open_msg;
struct vmbus_channel_msginfo *open_info = NULL;
struct page *page = newchannel->ringbuffer_page;
u32 send_pages, recv_pages;
unsigned long flags;
int err;

ret = hv_ringbuffer_init(&newchannel->inbound,
&page[send_ringbuffer_size >> PAGE_SHIFT],
recv_ringbuffer_size >> PAGE_SHIFT);
if (ret != 0) {
err = ret;
goto error_free_pages;
if (userdatalen > MAX_USER_DEFINED_BYTES)
return -EINVAL;

send_pages = newchannel->ringbuffer_send_offset;
recv_pages = newchannel->ringbuffer_pagecount - send_pages;

spin_lock_irqsave(&newchannel->lock, flags);
if (newchannel->state != CHANNEL_OPEN_STATE) {
spin_unlock_irqrestore(&newchannel->lock, flags);
return -EINVAL;
}
spin_unlock_irqrestore(&newchannel->lock, flags);

newchannel->state = CHANNEL_OPENING_STATE;
newchannel->onchannel_callback = onchannelcallback;
newchannel->channel_callback_context = context;

err = hv_ringbuffer_init(&newchannel->outbound, page, send_pages);
if (err)
goto error_clean_ring;

err = hv_ringbuffer_init(&newchannel->inbound,
&page[send_pages], recv_pages);
if (err)
goto error_clean_ring;

/* Establish the gpadl for the ring buffer */
newchannel->ringbuffer_gpadlhandle = 0;

ret = vmbus_establish_gpadl(newchannel,
page_address(page),
send_ringbuffer_size +
recv_ringbuffer_size,
err = vmbus_establish_gpadl(newchannel,
page_address(newchannel->ringbuffer_page),
(send_pages + recv_pages) << PAGE_SHIFT,
&newchannel->ringbuffer_gpadlhandle);

if (ret != 0) {
err = ret;
goto error_free_pages;
}
if (err)
goto error_clean_ring;

/* Create and init the channel open message */
open_info = kmalloc(sizeof(*open_info) +
Expand All @@ -175,15 +187,9 @@ int vmbus_open(struct vmbus_channel *newchannel, u32 send_ringbuffer_size,
open_msg->openid = newchannel->offermsg.child_relid;
open_msg->child_relid = newchannel->offermsg.child_relid;
open_msg->ringbuffer_gpadlhandle = newchannel->ringbuffer_gpadlhandle;
open_msg->downstream_ringbuffer_pageoffset = send_ringbuffer_size >>
PAGE_SHIFT;
open_msg->downstream_ringbuffer_pageoffset = newchannel->ringbuffer_send_offset;
open_msg->target_vp = newchannel->target_vp;

if (userdatalen > MAX_USER_DEFINED_BYTES) {
err = -EINVAL;
goto error_free_gpadl;
}

if (userdatalen)
memcpy(open_msg->userdata, userdata, userdatalen);

Expand All @@ -194,18 +200,16 @@ int vmbus_open(struct vmbus_channel *newchannel, u32 send_ringbuffer_size,

if (newchannel->rescind) {
err = -ENODEV;
goto error_free_gpadl;
goto error_free_info;
}

ret = vmbus_post_msg(open_msg,
err = vmbus_post_msg(open_msg,
sizeof(struct vmbus_channel_open_channel), true);

trace_vmbus_open(open_msg, ret);
trace_vmbus_open(open_msg, err);

if (ret != 0) {
err = ret;
if (err != 0)
goto error_clean_msglist;
}

wait_for_completion(&open_info->waitevent);

Expand All @@ -215,12 +219,12 @@ int vmbus_open(struct vmbus_channel *newchannel, u32 send_ringbuffer_size,

if (newchannel->rescind) {
err = -ENODEV;
goto error_free_gpadl;
goto error_free_info;
}

if (open_info->response.open_result.status) {
err = -EAGAIN;
goto error_free_gpadl;
goto error_free_info;
}

newchannel->state = CHANNEL_OPENED_STATE;
Expand All @@ -231,18 +235,50 @@ int vmbus_open(struct vmbus_channel *newchannel, u32 send_ringbuffer_size,
spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
list_del(&open_info->msglistentry);
spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);

error_free_info:
kfree(open_info);
error_free_gpadl:
vmbus_teardown_gpadl(newchannel, newchannel->ringbuffer_gpadlhandle);
kfree(open_info);
error_free_pages:
newchannel->ringbuffer_gpadlhandle = 0;
error_clean_ring:
hv_ringbuffer_cleanup(&newchannel->outbound);
hv_ringbuffer_cleanup(&newchannel->inbound);
__free_pages(page, order);
error_set_chnstate:
newchannel->state = CHANNEL_OPEN_STATE;
return err;
}

/*
* vmbus_connect_ring - Open the channel but reuse ring buffer
*/
int vmbus_connect_ring(struct vmbus_channel *newchannel,
void (*onchannelcallback)(void *context), void *context)
{
return __vmbus_open(newchannel, NULL, 0, onchannelcallback, context);
}
EXPORT_SYMBOL_GPL(vmbus_connect_ring);

/*
* vmbus_open - Open the specified channel.
*/
int vmbus_open(struct vmbus_channel *newchannel,
u32 send_ringbuffer_size, u32 recv_ringbuffer_size,
void *userdata, u32 userdatalen,
void (*onchannelcallback)(void *context), void *context)
{
int err;

err = vmbus_alloc_ring(newchannel, send_ringbuffer_size,
recv_ringbuffer_size);
if (err)
return err;

err = __vmbus_open(newchannel, userdata, userdatalen,
onchannelcallback, context);
if (err)
vmbus_free_ring(newchannel);

return err;
}
EXPORT_SYMBOL_GPL(vmbus_open);

/* Used for Hyper-V Socket: a guest client's connect() to the host */
Expand Down Expand Up @@ -610,10 +646,8 @@ static int vmbus_close_internal(struct vmbus_channel *channel)
* in Hyper-V Manager), the driver's remove() invokes vmbus_close():
* here we should skip most of the below cleanup work.
*/
if (channel->state != CHANNEL_OPENED_STATE) {
ret = -EINVAL;
goto out;
}
if (channel->state != CHANNEL_OPENED_STATE)
return -EINVAL;

channel->state = CHANNEL_OPEN_STATE;

Expand All @@ -635,11 +669,10 @@ static int vmbus_close_internal(struct vmbus_channel *channel)
* If we failed to post the close msg,
* it is perhaps better to leak memory.
*/
goto out;
}

/* Tear down the gpadl for the channel's ring buffer */
if (channel->ringbuffer_gpadlhandle) {
else if (channel->ringbuffer_gpadlhandle) {
ret = vmbus_teardown_gpadl(channel,
channel->ringbuffer_gpadlhandle);
if (ret) {
Expand All @@ -648,59 +681,63 @@ static int vmbus_close_internal(struct vmbus_channel *channel)
* If we failed to teardown gpadl,
* it is perhaps better to leak memory.
*/
goto out;
}
}

/* Cleanup the ring buffers for this channel */
hv_ringbuffer_cleanup(&channel->outbound);
hv_ringbuffer_cleanup(&channel->inbound);

__free_pages(channel->ringbuffer_page,
get_order(channel->ringbuffer_pagecount << PAGE_SHIFT));
channel->ringbuffer_gpadlhandle = 0;
}

out:
return ret;
}

/*
* vmbus_close - Close the specified channel
*/
void vmbus_close(struct vmbus_channel *channel)
/* disconnect ring - close all channels */
int vmbus_disconnect_ring(struct vmbus_channel *channel)
{
struct list_head *cur, *tmp;
struct vmbus_channel *cur_channel;
struct vmbus_channel *cur_channel, *tmp;
unsigned long flags;
LIST_HEAD(list);
int ret;

if (channel->primary_channel != NULL) {
/*
* We will only close sub-channels when
* the primary is closed.
*/
return;
}
/*
* Close all the sub-channels first and then close the
* primary channel.
*/
list_for_each_safe(cur, tmp, &channel->sc_list) {
cur_channel = list_entry(cur, struct vmbus_channel, sc_list);
if (cur_channel->rescind) {
if (channel->primary_channel != NULL)
return -EINVAL;

/* Snapshot the list of subchannels */
spin_lock_irqsave(&channel->lock, flags);
list_splice_init(&channel->sc_list, &list);
channel->num_sc = 0;
spin_unlock_irqrestore(&channel->lock, flags);

list_for_each_entry_safe(cur_channel, tmp, &list, sc_list) {
if (cur_channel->rescind)
wait_for_completion(&cur_channel->rescind_event);
mutex_lock(&vmbus_connection.channel_mutex);
vmbus_close_internal(cur_channel);
hv_process_channel_removal(cur_channel);
} else {
mutex_lock(&vmbus_connection.channel_mutex);
vmbus_close_internal(cur_channel);

mutex_lock(&vmbus_connection.channel_mutex);
if (vmbus_close_internal(cur_channel) == 0) {
vmbus_free_ring(cur_channel);

if (cur_channel->rescind)
hv_process_channel_removal(cur_channel);
}
mutex_unlock(&vmbus_connection.channel_mutex);
}

/*
* Now close the primary.
*/
mutex_lock(&vmbus_connection.channel_mutex);
vmbus_close_internal(channel);
ret = vmbus_close_internal(channel);
mutex_unlock(&vmbus_connection.channel_mutex);

return ret;
}
EXPORT_SYMBOL_GPL(vmbus_disconnect_ring);

/*
* vmbus_close - Close the specified channel
*/
void vmbus_close(struct vmbus_channel *channel)
{
if (vmbus_disconnect_ring(channel) == 0)
vmbus_free_ring(channel);
}
EXPORT_SYMBOL_GPL(vmbus_close);

Expand Down
1 change: 1 addition & 0 deletions drivers/hv/ring_buffer.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -241,6 +241,7 @@ int hv_ringbuffer_init(struct hv_ring_buffer_info *ring_info,
void hv_ringbuffer_cleanup(struct hv_ring_buffer_info *ring_info)
{
vunmap(ring_info->ring_buffer);
ring_info->ring_buffer = NULL;
}

/* Write to the ring buffer. */
Expand Down
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