svn commit: r309225 - in head/sys/dev/hyperv: include vmbus
Sepherosa Ziehau
sephe at FreeBSD.org
Mon Nov 28 05:07:50 UTC 2016
Author: sephe
Date: Mon Nov 28 05:07:48 2016
New Revision: 309225
URL: https://svnweb.freebsd.org/changeset/base/309225
Log:
hyperv/vmbus: Add supportive transaction wait function.
This function supports channel revocation properly.
MFC after: 1 week
Sponsored by: Microsoft
Differential Revision: https://reviews.freebsd.org/D8611
Modified:
head/sys/dev/hyperv/include/vmbus.h
head/sys/dev/hyperv/vmbus/vmbus_chan.c
Modified: head/sys/dev/hyperv/include/vmbus.h
==============================================================================
--- head/sys/dev/hyperv/include/vmbus.h Mon Nov 28 04:53:36 2016 (r309224)
+++ head/sys/dev/hyperv/include/vmbus.h Mon Nov 28 05:07:48 2016 (r309225)
@@ -116,6 +116,7 @@ struct vmbus_chan_br {
};
struct vmbus_channel;
+struct vmbus_xact;
struct vmbus_xact_ctx;
struct hyperv_guid;
struct task;
@@ -173,6 +174,8 @@ void vmbus_chan_run_task(struct vmbus_c
void vmbus_chan_set_orphan(struct vmbus_channel *chan,
struct vmbus_xact_ctx *);
void vmbus_chan_unset_orphan(struct vmbus_channel *chan);
+const void *vmbus_chan_xact_wait(const struct vmbus_channel *chan,
+ struct vmbus_xact *xact, size_t *resp_len, bool can_sleep);
int vmbus_chan_gpadl_connect(struct vmbus_channel *chan,
bus_addr_t paddr, int size, uint32_t *gpadl);
Modified: head/sys/dev/hyperv/vmbus/vmbus_chan.c
==============================================================================
--- head/sys/dev/hyperv/vmbus/vmbus_chan.c Mon Nov 28 04:53:36 2016 (r309224)
+++ head/sys/dev/hyperv/vmbus/vmbus_chan.c Mon Nov 28 05:07:48 2016 (r309225)
@@ -1927,3 +1927,37 @@ vmbus_chan_unset_orphan(struct vmbus_cha
chan->ch_orphan_xact = NULL;
sx_xunlock(&chan->ch_orphan_lock);
}
+
+const void *
+vmbus_chan_xact_wait(const struct vmbus_channel *chan,
+ struct vmbus_xact *xact, size_t *resp_len, bool can_sleep)
+{
+ const void *ret;
+
+ if (can_sleep)
+ ret = vmbus_xact_wait(xact, resp_len);
+ else
+ ret = vmbus_xact_busywait(xact, resp_len);
+ if (vmbus_chan_is_revoked(chan)) {
+ /*
+ * This xact probably is interrupted, and the
+ * interruption can race the reply reception,
+ * so we have to make sure that there are nothing
+ * left on the RX bufring, i.e. this xact will
+ * not be touched, once this function returns.
+ *
+ * Since the hypervisor will not put more data
+ * onto the RX bufring once the channel is revoked,
+ * the following loop will be terminated, once all
+ * data are drained by the driver's channel
+ * callback.
+ */
+ while (!vmbus_chan_rx_empty(chan)) {
+ if (can_sleep)
+ pause("chxact", 1);
+ else
+ DELAY(1000);
+ }
+ }
+ return (ret);
+}
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