vmbus: change to per channel tasklet (631e63a9) · Commits · e / devices / android_kernel_oneplus_sm8150

drivers/hv/channel.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -530,7 +530,7 @@ static int vmbus_close_internal(struct vmbus_channel *channel)
		int ret;

		/*
		* process_chn_event(), running in the tasklet, can race
		* vmbus_on_event(), running in the tasklet, can race
		* with vmbus_close_internal() in the case of SMP guest, e.g., when
		* the former is accessing channel->inbound.ring_buffer, the latter
		* could be freeing the ring_buffer pages.

drivers/hv/channel_mgmt.c

+7 −9

Original line number	Diff line number	Diff line
		@@ -339,6 +339,9 @@ static struct vmbus_channel *alloc_channel(void)
		INIT_LIST_HEAD(&channel->sc_list);
		INIT_LIST_HEAD(&channel->percpu_list);

		tasklet_init(&channel->callback_event,
		vmbus_on_event, (unsigned long)channel);

		return channel;
		}

		@@ -347,6 +350,7 @@ static struct vmbus_channel *alloc_channel(void)
		*/
		static void free_channel(struct vmbus_channel *channel)
		{
		tasklet_kill(&channel->callback_event);
		kfree(channel);
		}

		@@ -380,21 +384,15 @@ static void vmbus_release_relid(u32 relid)

		void hv_event_tasklet_disable(struct vmbus_channel *channel)
		{
		struct hv_per_cpu_context *hv_cpu;

		hv_cpu = per_cpu_ptr(hv_context.cpu_context, channel->target_cpu);
		tasklet_disable(&hv_cpu->event_dpc);
		tasklet_disable(&channel->callback_event);
		}

		void hv_event_tasklet_enable(struct vmbus_channel *channel)
		{
		struct hv_per_cpu_context *hv_cpu;

		hv_cpu = per_cpu_ptr(hv_context.cpu_context, channel->target_cpu);
		tasklet_enable(&hv_cpu->event_dpc);
		tasklet_enable(&channel->callback_event);

		/* In case there is any pending event */
		tasklet_schedule(&hv_cpu->event_dpc);
		tasklet_schedule(&channel->callback_event);
		}

		void hv_process_channel_removal(struct vmbus_channel *channel, u32 relid)

drivers/hv/connection.c

+3 −75

Original line number	Diff line number	Diff line
		@@ -259,29 +259,6 @@ void vmbus_disconnect(void)
		vmbus_connection.monitor_pages[1] = NULL;
		}

		/*
		* Map the given relid to the corresponding channel based on the
		* per-cpu list of channels that have been affinitized to this CPU.
		* This will be used in the channel callback path as we can do this
		* mapping in a lock-free fashion.
		*/
		static struct vmbus_channel *pcpu_relid2channel(u32 relid)
		{
		struct hv_per_cpu_context *hv_cpu
		= this_cpu_ptr(hv_context.cpu_context);
		struct vmbus_channel *found_channel = NULL;
		struct vmbus_channel *channel;

		list_for_each_entry(channel, &hv_cpu->chan_list, percpu_list) {
		if (channel->offermsg.child_relid == relid) {
		found_channel = channel;
		break;
		}
		}

		return found_channel;
		}

		/*
		* relid2channel - Get the channel object given its
		* child relative id (ie channel id)
		@@ -318,24 +295,15 @@ struct vmbus_channel *relid2channel(u32 relid)
		}

		/*
		* process_chn_event - Process a channel event notification
		* vmbus_on_event - Process a channel event notification
		*/
		static void process_chn_event(u32 relid)
		void vmbus_on_event(unsigned long data)
		{
		struct vmbus_channel *channel;
		struct vmbus_channel channel = (void ) data;
		void *arg;
		bool read_state;
		u32 bytes_to_read;

		/*
		* Find the channel based on this relid and invokes the
		* channel callback to process the event
		*/
		channel = pcpu_relid2channel(relid);

		if (!channel)
		return;

		/*
		* A channel once created is persistent even when there
		* is no driver handling the device. An unloading driver
		@@ -344,7 +312,6 @@ static void process_chn_event(u32 relid)
		* 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;
		@@ -372,45 +339,6 @@ static void process_chn_event(u32 relid)
		}
		}

		/*
		* vmbus_on_event - Handler for events
		*/
		void vmbus_on_event(unsigned long data)
		{
		struct hv_per_cpu_context hv_cpu = (void )data;
		unsigned long *recv_int_page;
		u32 maxbits, relid;

		if (vmbus_proto_version < VERSION_WIN8) {
		maxbits = MAX_NUM_CHANNELS_SUPPORTED;
		recv_int_page = vmbus_connection.recv_int_page;
		} else {
		/*
		* When the host is win8 and beyond, the event page
		* can be directly checked to get the id of the channel
		* that has the interrupt pending.
		*/
		void *page_addr = hv_cpu->synic_event_page;
		union hv_synic_event_flags *event
		= (union hv_synic_event_flags *)page_addr +
		VMBUS_MESSAGE_SINT;

		maxbits = HV_EVENT_FLAGS_COUNT;
		recv_int_page = event->flags;
		}

		if (unlikely(!recv_int_page))
		return;

		for_each_set_bit(relid, recv_int_page, maxbits) {
		if (sync_test_and_clear_bit(relid, recv_int_page)) {
		/* Special case - vmbus channel protocol msg */
		if (relid != 0)
		process_chn_event(relid);
		}
		}
		}

		/*
		* vmbus_post_msg - Send a msg on the vmbus's message connection
		*/

drivers/hv/hv.c

+0 −2

Original line number	Diff line number	Diff line
		@@ -156,8 +156,6 @@ int hv_synic_alloc(void)
		= per_cpu_ptr(hv_context.cpu_context, cpu);

		memset(hv_cpu, 0, sizeof(*hv_cpu));
		tasklet_init(&hv_cpu->event_dpc,
		vmbus_on_event, (unsigned long) hv_cpu);
		tasklet_init(&hv_cpu->msg_dpc,
		vmbus_on_msg_dpc, (unsigned long) hv_cpu);

drivers/hv/hyperv_vmbus.h

+0 −1

Original line number	Diff line number	Diff line
		@@ -206,7 +206,6 @@ struct hv_per_cpu_context {
		* we will manage the tasklet that handles events messages on a per CPU
		* basis.
		*/
		struct tasklet_struct event_dpc;
		struct tasklet_struct msg_dpc;

		/*