diff options
| -rw-r--r-- | drivers/hv/channel_mgmt.c | 7 | ||||
| -rw-r--r-- | drivers/hv/connection.c | 27 | ||||
| -rw-r--r-- | drivers/hv/hv_util.c | 3 | ||||
| -rw-r--r-- | drivers/hv/vmbus_drv.c | 26 | ||||
| -rw-r--r-- | drivers/uio/uio_hv_generic.c | 2 | ||||
| -rw-r--r-- | include/linux/hyperv.h | 31 |
6 files changed, 55 insertions, 41 deletions
diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c index 2f6270d76b79..b2bb5aafaa2f 100644 --- a/drivers/hv/channel_mgmt.c +++ b/drivers/hv/channel_mgmt.c @@ -820,13 +820,6 @@ static void vmbus_onoffer(struct vmbus_channel_message_header *hdr) } /* - * By default we setup state to enable batched - * reading. A specific service can choose to - * disable this prior to opening the channel. - */ - newchannel->batched_reading = true; - - /* * Setup state for signalling the host. */ newchannel->sig_event = (struct hv_input_signal_event *) diff --git a/drivers/hv/connection.c b/drivers/hv/connection.c index 27e72dc07e12..a8366fec1458 100644 --- a/drivers/hv/connection.c +++ b/drivers/hv/connection.c @@ -300,9 +300,7 @@ struct vmbus_channel *relid2channel(u32 relid) void vmbus_on_event(unsigned long data) { struct vmbus_channel *channel = (void *) data; - void *arg; - bool read_state; - u32 bytes_to_read; + void (*callback_fn)(void *); /* * A channel once created is persistent even when there @@ -312,9 +310,13 @@ void vmbus_on_event(unsigned long data) * Thus, checking and invoking the driver specific callback takes * care of orderly unloading of the driver. */ - if (channel->onchannel_callback != NULL) { - arg = channel->channel_callback_context; - read_state = channel->batched_reading; + callback_fn = READ_ONCE(channel->onchannel_callback); + if (unlikely(callback_fn == NULL)) + return; + + (*callback_fn)(channel->channel_callback_context); + + if (channel->callback_mode == HV_CALL_BATCHED) { /* * This callback reads the messages sent by the host. * We can optimize host to guest signaling by ensuring: @@ -326,16 +328,11 @@ void vmbus_on_event(unsigned long data) * state is set we check to see if additional packets are * available to read. In this case we repeat the process. */ + if (hv_end_read(&channel->inbound) != 0) { + hv_begin_read(&channel->inbound); - do { - if (read_state) - hv_begin_read(&channel->inbound); - channel->onchannel_callback(arg); - if (read_state) - bytes_to_read = hv_end_read(&channel->inbound); - else - bytes_to_read = 0; - } while (read_state && (bytes_to_read != 0)); + tasklet_schedule(&channel->callback_event); + } } } diff --git a/drivers/hv/hv_util.c b/drivers/hv/hv_util.c index 098cd3dc7db2..3042eaa13062 100644 --- a/drivers/hv/hv_util.c +++ b/drivers/hv/hv_util.c @@ -435,8 +435,7 @@ static int util_probe(struct hv_device *dev, * Turn off batched reading for all util drivers before we open the * channel. */ - - set_channel_read_state(dev->channel, false); + set_channel_read_mode(dev->channel, HV_CALL_DIRECT); hv_set_drvdata(dev, srv); diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c index eaf1a10b0245..f7f6b9144b07 100644 --- a/drivers/hv/vmbus_drv.c +++ b/drivers/hv/vmbus_drv.c @@ -887,6 +887,18 @@ msg_handled: /* + * Direct callback for channels using other deferred processing + */ +static void vmbus_channel_isr(struct vmbus_channel *channel) +{ + void (*callback_fn)(void *); + + callback_fn = READ_ONCE(channel->onchannel_callback); + if (likely(callback_fn != NULL)) + (*callback_fn)(channel->channel_callback_context); +} + +/* * Schedule all channels with events pending */ static void vmbus_chan_sched(struct hv_per_cpu_context *hv_cpu) @@ -927,9 +939,19 @@ static void vmbus_chan_sched(struct hv_per_cpu_context *hv_cpu) /* Find channel based on relid */ list_for_each_entry(channel, &hv_cpu->chan_list, percpu_list) { - if (channel->offermsg.child_relid == relid) { - tasklet_schedule(&channel->callback_event); + if (channel->offermsg.child_relid != relid) + continue; + + switch (channel->callback_mode) { + case HV_CALL_ISR: + vmbus_channel_isr(channel); break; + + case HV_CALL_BATCHED: + hv_begin_read(&channel->inbound); + /* fallthrough */ + case HV_CALL_DIRECT: + tasklet_schedule(&channel->callback_event); } } } diff --git a/drivers/uio/uio_hv_generic.c b/drivers/uio/uio_hv_generic.c index 50958f167305..48d5327d38d4 100644 --- a/drivers/uio/uio_hv_generic.c +++ b/drivers/uio/uio_hv_generic.c @@ -125,7 +125,7 @@ hv_uio_probe(struct hv_device *dev, goto fail; dev->channel->inbound.ring_buffer->interrupt_mask = 1; - dev->channel->batched_reading = false; + set_channel_read_mode(dev->channel, HV_CALL_DIRECT); /* Fill general uio info */ pdata->info.name = "uio_hv_generic"; diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h index 69afc9337c0d..e5aac5c051f7 100644 --- a/include/linux/hyperv.h +++ b/include/linux/hyperv.h @@ -748,19 +748,21 @@ struct vmbus_channel { void *channel_callback_context; /* - * A channel can be marked for efficient (batched) - * reading: - * If batched_reading is set to "true", we read until the - * channel is empty and hold off interrupts from the host - * during the entire read process. - * If batched_reading is set to "false", the client is not - * going to perform batched reading. - * - * By default we will enable batched reading; specific - * drivers that don't want this behavior can turn it off. + * A channel can be marked for one of three modes of reading: + * BATCHED - callback called from taslket and should read + * channel until empty. Interrupts from the host + * are masked while read is in process (default). + * DIRECT - callback called from tasklet (softirq). + * ISR - callback called in interrupt context and must + * invoke its own deferred processing. + * Host interrupts are disabled and must be re-enabled + * when ring is empty. */ - - bool batched_reading; + enum hv_callback_mode { + HV_CALL_BATCHED, + HV_CALL_DIRECT, + HV_CALL_ISR + } callback_mode; bool is_dedicated_interrupt; struct hv_input_signal_event_buffer sig_buf; @@ -910,9 +912,10 @@ static inline void set_channel_affinity_state(struct vmbus_channel *c, c->affinity_policy = policy; } -static inline void set_channel_read_state(struct vmbus_channel *c, bool state) +static inline void set_channel_read_mode(struct vmbus_channel *c, + enum hv_callback_mode mode) { - c->batched_reading = state; + c->callback_mode = mode; } static inline void set_per_channel_state(struct vmbus_channel *c, void *s) |