The only generic interface to execute asynchronously in the BH context is tasklet; however, it's marked deprecated and has some design flaws. To replace tasklets, BH workqueue support was recently added. A BH workqueue behaves similarly to regular workqueues except that the queued work items are executed in the BH context. This patch converts drivers/hv/* from tasklet to BH workqueue. Based on the work done by Tejun Heo <tj@xxxxxxxxxx> Branch: https://git.kernel.org/pub/scm/linux/kernel/git/tj/wq.git for-6.10 Signed-off-by: Allen Pais <allen.lkml@xxxxxxxxx> --- drivers/hv/channel.c | 8 ++++---- drivers/hv/channel_mgmt.c | 5 ++--- drivers/hv/connection.c | 9 +++++---- drivers/hv/hv.c | 3 +-- drivers/hv/hv_balloon.c | 4 ++-- drivers/hv/hv_fcopy.c | 8 ++++---- drivers/hv/hv_kvp.c | 8 ++++---- drivers/hv/hv_snapshot.c | 8 ++++---- drivers/hv/hyperv_vmbus.h | 9 +++++---- drivers/hv/vmbus_drv.c | 20 +++++++++++--------- include/linux/hyperv.h | 2 +- 11 files changed, 43 insertions(+), 41 deletions(-) diff --git a/drivers/hv/channel.c b/drivers/hv/channel.c index adbf674355b2..876d78eb4dce 100644 --- a/drivers/hv/channel.c +++ b/drivers/hv/channel.c @@ -859,7 +859,7 @@ void vmbus_reset_channel_cb(struct vmbus_channel *channel) unsigned long flags; /* - * vmbus_on_event(), running in the per-channel tasklet, can race + * vmbus_on_event(), running in the per-channel work, 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, so here we must stop it @@ -871,7 +871,7 @@ void vmbus_reset_channel_cb(struct vmbus_channel *channel) * and that the channel ring buffer is no longer being accessed, cf. * the calls to napi_disable() in netvsc_device_remove(). */ - tasklet_disable(&channel->callback_event); + disable_work_sync(&channel->callback_event); /* See the inline comments in vmbus_chan_sched(). */ spin_lock_irqsave(&channel->sched_lock, flags); @@ -880,8 +880,8 @@ void vmbus_reset_channel_cb(struct vmbus_channel *channel) channel->sc_creation_callback = NULL; - /* Re-enable tasklet for use on re-open */ - tasklet_enable(&channel->callback_event); + /* Re-enable work for use on re-open */ + enable_and_queue_work(system_bh_wq, &channel->callback_event); } static int vmbus_close_internal(struct vmbus_channel *channel) diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c index 2f4d09ce027a..58397071a0de 100644 --- a/drivers/hv/channel_mgmt.c +++ b/drivers/hv/channel_mgmt.c @@ -353,8 +353,7 @@ static struct vmbus_channel *alloc_channel(void) INIT_LIST_HEAD(&channel->sc_list); - tasklet_init(&channel->callback_event, - vmbus_on_event, (unsigned long)channel); + INIT_WORK(&channel->callback_event, vmbus_on_event); hv_ringbuffer_pre_init(channel); @@ -366,7 +365,7 @@ static struct vmbus_channel *alloc_channel(void) */ static void free_channel(struct vmbus_channel *channel) { - tasklet_kill(&channel->callback_event); + cancel_work_sync(&channel->callback_event); vmbus_remove_channel_attr_group(channel); kobject_put(&channel->kobj); diff --git a/drivers/hv/connection.c b/drivers/hv/connection.c index 3cabeeabb1ca..f2a3394a8303 100644 --- a/drivers/hv/connection.c +++ b/drivers/hv/connection.c @@ -372,12 +372,13 @@ struct vmbus_channel *relid2channel(u32 relid) * 3. Once we return, enable signaling from the host. Once this * state is set we check to see if additional packets are * available to read. In this case we repeat the process. - * If this tasklet has been running for a long time + * If this work has been running for a long time * then reschedule ourselves. */ -void vmbus_on_event(unsigned long data) +void vmbus_on_event(struct work_struct *t) { - struct vmbus_channel *channel = (void *) data; + struct vmbus_channel *channel = from_work(channel, t, + callback_event); void (*callback_fn)(void *context); trace_vmbus_on_event(channel); @@ -401,7 +402,7 @@ void vmbus_on_event(unsigned long data) return; hv_begin_read(&channel->inbound); - tasklet_schedule(&channel->callback_event); + queue_work(system_bh_wq, &channel->callback_event); } /* diff --git a/drivers/hv/hv.c b/drivers/hv/hv.c index a8ad728354cb..2af92f08f9ce 100644 --- a/drivers/hv/hv.c +++ b/drivers/hv/hv.c @@ -119,8 +119,7 @@ int hv_synic_alloc(void) for_each_present_cpu(cpu) { hv_cpu = per_cpu_ptr(hv_context.cpu_context, cpu); - tasklet_init(&hv_cpu->msg_dpc, - vmbus_on_msg_dpc, (unsigned long) hv_cpu); + INIT_WORK(&hv_cpu->msg_dpc, vmbus_on_msg_dpc); if (ms_hyperv.paravisor_present && hv_isolation_type_tdx()) { hv_cpu->post_msg_page = (void *)get_zeroed_page(GFP_ATOMIC); diff --git a/drivers/hv/hv_balloon.c b/drivers/hv/hv_balloon.c index e000fa3b9f97..c7efa2ff4cdf 100644 --- a/drivers/hv/hv_balloon.c +++ b/drivers/hv/hv_balloon.c @@ -2083,7 +2083,7 @@ static int balloon_suspend(struct hv_device *hv_dev) { struct hv_dynmem_device *dm = hv_get_drvdata(hv_dev); - tasklet_disable(&hv_dev->channel->callback_event); + disable_work_sync(&hv_dev->channel->callback_event); cancel_work_sync(&dm->balloon_wrk.wrk); cancel_work_sync(&dm->ha_wrk.wrk); @@ -2094,7 +2094,7 @@ static int balloon_suspend(struct hv_device *hv_dev) vmbus_close(hv_dev->channel); } - tasklet_enable(&hv_dev->channel->callback_event); + enable_and_queue_work(system_bh_wq, &hv_dev->channel->callback_event); return 0; diff --git a/drivers/hv/hv_fcopy.c b/drivers/hv/hv_fcopy.c index 922d83eb7ddf..fd6799293c17 100644 --- a/drivers/hv/hv_fcopy.c +++ b/drivers/hv/hv_fcopy.c @@ -71,7 +71,7 @@ static void fcopy_poll_wrapper(void *channel) { /* Transaction is finished, reset the state here to avoid races. */ fcopy_transaction.state = HVUTIL_READY; - tasklet_schedule(&((struct vmbus_channel *)channel)->callback_event); + queue_work(system_bh_wq, &((struct vmbus_channel *)channel)->callback_event); } static void fcopy_timeout_func(struct work_struct *dummy) @@ -391,7 +391,7 @@ int hv_fcopy_pre_suspend(void) if (!fcopy_msg) return -ENOMEM; - tasklet_disable(&channel->callback_event); + disable_work_sync(&channel->callback_event); fcopy_msg->operation = CANCEL_FCOPY; @@ -404,7 +404,7 @@ int hv_fcopy_pre_suspend(void) fcopy_transaction.state = HVUTIL_READY; - /* tasklet_enable() will be called in hv_fcopy_pre_resume(). */ + /* enable_and_queue_work(system_bh_wq, ) will be called in hv_fcopy_pre_resume(). */ return 0; } @@ -412,7 +412,7 @@ int hv_fcopy_pre_resume(void) { struct vmbus_channel *channel = fcopy_transaction.recv_channel; - tasklet_enable(&channel->callback_event); + enable_and_queue_work(system_bh_wq, &channel->callback_event); return 0; } diff --git a/drivers/hv/hv_kvp.c b/drivers/hv/hv_kvp.c index d35b60c06114..85b8fb4a3d2e 100644 --- a/drivers/hv/hv_kvp.c +++ b/drivers/hv/hv_kvp.c @@ -113,7 +113,7 @@ static void kvp_poll_wrapper(void *channel) { /* Transaction is finished, reset the state here to avoid races. */ kvp_transaction.state = HVUTIL_READY; - tasklet_schedule(&((struct vmbus_channel *)channel)->callback_event); + queue_work(system_bh_wq, &((struct vmbus_channel *)channel)->callback_event); } static void kvp_register_done(void) @@ -160,7 +160,7 @@ static void kvp_timeout_func(struct work_struct *dummy) static void kvp_host_handshake_func(struct work_struct *dummy) { - tasklet_schedule(&kvp_transaction.recv_channel->callback_event); + queue_work(system_bh_wq, &kvp_transaction.recv_channel->callback_event); } static int kvp_handle_handshake(struct hv_kvp_msg *msg) @@ -786,7 +786,7 @@ int hv_kvp_pre_suspend(void) { struct vmbus_channel *channel = kvp_transaction.recv_channel; - tasklet_disable(&channel->callback_event); + disable_work_sync(&channel->callback_event); /* * If there is a pending transtion, it's unnecessary to tell the host @@ -809,7 +809,7 @@ int hv_kvp_pre_resume(void) { struct vmbus_channel *channel = kvp_transaction.recv_channel; - tasklet_enable(&channel->callback_event); + enable_and_queue_work(system_bh_wq, &channel->callback_event); return 0; } diff --git a/drivers/hv/hv_snapshot.c b/drivers/hv/hv_snapshot.c index 0d2184be1691..46c2263d2591 100644 --- a/drivers/hv/hv_snapshot.c +++ b/drivers/hv/hv_snapshot.c @@ -83,7 +83,7 @@ static void vss_poll_wrapper(void *channel) { /* Transaction is finished, reset the state here to avoid races. */ vss_transaction.state = HVUTIL_READY; - tasklet_schedule(&((struct vmbus_channel *)channel)->callback_event); + queue_work(system_bh_wq, &((struct vmbus_channel *)channel)->callback_event); } /* @@ -421,7 +421,7 @@ int hv_vss_pre_suspend(void) if (!vss_msg) return -ENOMEM; - tasklet_disable(&channel->callback_event); + disable_work_sync(&channel->callback_event); vss_msg->vss_hdr.operation = VSS_OP_THAW; @@ -435,7 +435,7 @@ int hv_vss_pre_suspend(void) vss_transaction.state = HVUTIL_READY; - /* tasklet_enable() will be called in hv_vss_pre_resume(). */ + /* enable_and_queue_work() will be called in hv_vss_pre_resume(). */ return 0; } @@ -443,7 +443,7 @@ int hv_vss_pre_resume(void) { struct vmbus_channel *channel = vss_transaction.recv_channel; - tasklet_enable(&channel->callback_event); + enable_and_queue_work(system_bh_wq, &channel->callback_event); return 0; } diff --git a/drivers/hv/hyperv_vmbus.h b/drivers/hv/hyperv_vmbus.h index f6b1e710f805..95ca570ac7af 100644 --- a/drivers/hv/hyperv_vmbus.h +++ b/drivers/hv/hyperv_vmbus.h @@ -19,6 +19,7 @@ #include <linux/atomic.h> #include <linux/hyperv.h> #include <linux/interrupt.h> +#include <linux/workqueue.h> #include "hv_trace.h" @@ -136,10 +137,10 @@ struct hv_per_cpu_context { /* * Starting with win8, we can take channel interrupts on any CPU; - * we will manage the tasklet that handles events messages on a per CPU + * we will manage the work that handles events messages on a per CPU * basis. */ - struct tasklet_struct msg_dpc; + struct work_struct msg_dpc; }; struct hv_context { @@ -366,8 +367,8 @@ void vmbus_disconnect(void); int vmbus_post_msg(void *buffer, size_t buflen, bool can_sleep); -void vmbus_on_event(unsigned long data); -void vmbus_on_msg_dpc(unsigned long data); +void vmbus_on_event(struct work_struct *t); +void vmbus_on_msg_dpc(struct work_struct *t); int hv_kvp_init(struct hv_util_service *srv); void hv_kvp_deinit(void); diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c index 4cb17603a828..28490068cacc 100644 --- a/drivers/hv/vmbus_drv.c +++ b/drivers/hv/vmbus_drv.c @@ -1025,9 +1025,9 @@ static void vmbus_onmessage_work(struct work_struct *work) kfree(ctx); } -void vmbus_on_msg_dpc(unsigned long data) +void vmbus_on_msg_dpc(struct work_struct *t) { - struct hv_per_cpu_context *hv_cpu = (void *)data; + struct hv_per_cpu_context *hv_cpu = from_work(hv_cpu, t, msg_dpc); void *page_addr = hv_cpu->synic_message_page; struct hv_message msg_copy, *msg = (struct hv_message *)page_addr + VMBUS_MESSAGE_SINT; @@ -1131,7 +1131,7 @@ void vmbus_on_msg_dpc(unsigned long data) * before sending the rescind message of the same * channel. These messages are sent to the guest's * connect CPU; the guest then starts processing them - * in the tasklet handler on this CPU: + * in the work handler on this CPU: * * VMBUS_CONNECT_CPU * @@ -1276,7 +1276,7 @@ static void vmbus_chan_sched(struct hv_per_cpu_context *hv_cpu) hv_begin_read(&channel->inbound); fallthrough; case HV_CALL_DIRECT: - tasklet_schedule(&channel->callback_event); + queue_work(system_bh_wq, &channel->callback_event); } sched_unlock: @@ -1304,7 +1304,7 @@ static void vmbus_isr(void) hv_stimer0_isr(); vmbus_signal_eom(msg, HVMSG_TIMER_EXPIRED); } else - tasklet_schedule(&hv_cpu->msg_dpc); + queue_work(system_bh_wq, &hv_cpu->msg_dpc); } add_interrupt_randomness(vmbus_interrupt); @@ -2371,10 +2371,12 @@ static int vmbus_bus_suspend(struct device *dev) hv_context.cpu_context, VMBUS_CONNECT_CPU); struct vmbus_channel *channel, *sc; - tasklet_disable(&hv_cpu->msg_dpc); + disable_work_sync(&hv_cpu->msg_dpc); vmbus_connection.ignore_any_offer_msg = true; - /* The tasklet_enable() takes care of providing a memory barrier */ - tasklet_enable(&hv_cpu->msg_dpc); + /* The enable_and_queue_work() takes care of + * providing a memory barrier + */ + enable_and_queue_work(system_bh_wq, &hv_cpu->msg_dpc); /* Drain all the workqueues as we are in suspend */ drain_workqueue(vmbus_connection.rescind_work_queue); @@ -2692,7 +2694,7 @@ static void __exit vmbus_exit(void) struct hv_per_cpu_context *hv_cpu = per_cpu_ptr(hv_context.cpu_context, cpu); - tasklet_kill(&hv_cpu->msg_dpc); + cancel_work_sync(&hv_cpu->msg_dpc); } hv_debug_rm_all_dir(); diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h index 6ef0557b4bff..db3d85ea5ce6 100644 --- a/include/linux/hyperv.h +++ b/include/linux/hyperv.h @@ -882,7 +882,7 @@ struct vmbus_channel { bool out_full_flag; /* Channel callback's invoked in softirq context */ - struct tasklet_struct callback_event; + struct work_struct callback_event; void (*onchannel_callback)(void *context); void *channel_callback_context; -- 2.17.1
