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/usb/* 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 Reviewed-by: Duncan Sands <duncan.sands@xxxxxxx> Signed-off-by: Allen Pais <allen.lkml@xxxxxxxxx> --- Changes in v3: - Fixed broken link Changes in v2: - Update code comments and commit message. Suggested by Greg K h - Retain local variable name(hcd.c). Suggested by Alan Stern - Link to v1:https://lore.kernel.org/all/20240327160314.9982-1-apais@xxxxxxxxxxxxxxxxxxx/T/#m2ec7868fbf102f1551ebe4c92d200848b94af3b1 --- drivers/usb/atm/usbatm.c | 51 +++++++++++++++-------------- drivers/usb/atm/usbatm.h | 3 +- drivers/usb/core/hcd.c | 4 +-- drivers/usb/gadget/udc/fsl_qe_udc.c | 21 ++++++------ drivers/usb/gadget/udc/fsl_qe_udc.h | 4 +-- drivers/usb/host/ehci-sched.c | 2 +- drivers/usb/host/fhci-hcd.c | 3 +- drivers/usb/host/fhci-sched.c | 10 +++--- drivers/usb/host/fhci.h | 5 +-- drivers/usb/host/xhci-dbgcap.h | 3 +- drivers/usb/host/xhci-dbgtty.c | 15 +++++---- include/linux/usb/cdc_ncm.h | 2 +- include/linux/usb/usbnet.h | 2 +- 13 files changed, 65 insertions(+), 60 deletions(-) diff --git a/drivers/usb/atm/usbatm.c b/drivers/usb/atm/usbatm.c index 2da6615fbb6f..1467d09a98c0 100644 --- a/drivers/usb/atm/usbatm.c +++ b/drivers/usb/atm/usbatm.c @@ -68,6 +68,7 @@ #include <linux/wait.h> #include <linux/kthread.h> #include <linux/ratelimit.h> +#include <linux/workqueue.h> #ifdef VERBOSE_DEBUG static int usbatm_print_packet(struct usbatm_data *instance, const unsigned char *data, int len); @@ -269,7 +270,7 @@ static void usbatm_complete(struct urb *urb) /* throttle processing in case of an error */ mod_timer(&channel->delay, jiffies + msecs_to_jiffies(THROTTLE_MSECS)); } else - tasklet_schedule(&channel->tasklet); + queue_work(system_bh_wq, &channel->work); } @@ -511,10 +512,10 @@ static unsigned int usbatm_write_cells(struct usbatm_data *instance, ** receive ** **************/ -static void usbatm_rx_process(struct tasklet_struct *t) +static void usbatm_rx_process(struct work_struct *t) { - struct usbatm_data *instance = from_tasklet(instance, t, - rx_channel.tasklet); + struct usbatm_data *instance = from_work(instance, t, + rx_channel.work); struct urb *urb; while ((urb = usbatm_pop_urb(&instance->rx_channel))) { @@ -565,10 +566,10 @@ static void usbatm_rx_process(struct tasklet_struct *t) ** send ** ***********/ -static void usbatm_tx_process(struct tasklet_struct *t) +static void usbatm_tx_process(struct work_struct *t) { - struct usbatm_data *instance = from_tasklet(instance, t, - tx_channel.tasklet); + struct usbatm_data *instance = from_work(instance, t, + tx_channel.work); struct sk_buff *skb = instance->current_skb; struct urb *urb = NULL; const unsigned int buf_size = instance->tx_channel.buf_size; @@ -632,13 +633,13 @@ static void usbatm_cancel_send(struct usbatm_data *instance, } spin_unlock_irq(&instance->sndqueue.lock); - tasklet_disable(&instance->tx_channel.tasklet); + disable_work_sync(&instance->tx_channel.work); if ((skb = instance->current_skb) && (UDSL_SKB(skb)->atm.vcc == vcc)) { atm_dbg(instance, "%s: popping current skb (0x%p)\n", __func__, skb); instance->current_skb = NULL; usbatm_pop(vcc, skb); } - tasklet_enable(&instance->tx_channel.tasklet); + enable_and_queue_work(system_bh_wq, &instance->tx_channel.work); } static int usbatm_atm_send(struct atm_vcc *vcc, struct sk_buff *skb) @@ -677,7 +678,7 @@ static int usbatm_atm_send(struct atm_vcc *vcc, struct sk_buff *skb) ctrl->crc = crc32_be(~0, skb->data, skb->len); skb_queue_tail(&instance->sndqueue, skb); - tasklet_schedule(&instance->tx_channel.tasklet); + queue_work(system_bh_wq, &instance->tx_channel.work); return 0; @@ -695,8 +696,8 @@ static void usbatm_destroy_instance(struct kref *kref) { struct usbatm_data *instance = container_of(kref, struct usbatm_data, refcount); - tasklet_kill(&instance->rx_channel.tasklet); - tasklet_kill(&instance->tx_channel.tasklet); + cancel_work_sync(&instance->rx_channel.work); + cancel_work_sync(&instance->tx_channel.work); usb_put_dev(instance->usb_dev); kfree(instance); } @@ -823,12 +824,12 @@ static int usbatm_atm_open(struct atm_vcc *vcc) vcc->dev_data = new; - tasklet_disable(&instance->rx_channel.tasklet); + disable_work_sync(&instance->rx_channel.work); instance->cached_vcc = new; instance->cached_vpi = vpi; instance->cached_vci = vci; list_add(&new->list, &instance->vcc_list); - tasklet_enable(&instance->rx_channel.tasklet); + enable_and_queue_work(system_bh_wq, &instance->rx_channel.work); set_bit(ATM_VF_ADDR, &vcc->flags); set_bit(ATM_VF_PARTIAL, &vcc->flags); @@ -858,14 +859,14 @@ static void usbatm_atm_close(struct atm_vcc *vcc) mutex_lock(&instance->serialize); /* vs self, usbatm_atm_open, usbatm_usb_disconnect */ - tasklet_disable(&instance->rx_channel.tasklet); + disable_work_sync(&instance->rx_channel.work); if (instance->cached_vcc == vcc_data) { instance->cached_vcc = NULL; instance->cached_vpi = ATM_VPI_UNSPEC; instance->cached_vci = ATM_VCI_UNSPEC; } list_del(&vcc_data->list); - tasklet_enable(&instance->rx_channel.tasklet); + enable_and_queue_work(system_bh_wq, &instance->rx_channel.work); kfree_skb(vcc_data->sarb); vcc_data->sarb = NULL; @@ -991,18 +992,18 @@ static int usbatm_heavy_init(struct usbatm_data *instance) return 0; } -static void usbatm_tasklet_schedule(struct timer_list *t) +static void usbatm_queue_work(system_bh_wq, struct timer_list *t) { struct usbatm_channel *channel = from_timer(channel, t, delay); - tasklet_schedule(&channel->tasklet); + queue_work(system_bh_wq, &channel->work); } static void usbatm_init_channel(struct usbatm_channel *channel) { spin_lock_init(&channel->lock); INIT_LIST_HEAD(&channel->list); - timer_setup(&channel->delay, usbatm_tasklet_schedule, 0); + timer_setup(&channel->delay, usbatm_queue_work, 0); } int usbatm_usb_probe(struct usb_interface *intf, const struct usb_device_id *id, @@ -1074,8 +1075,8 @@ int usbatm_usb_probe(struct usb_interface *intf, const struct usb_device_id *id, usbatm_init_channel(&instance->rx_channel); usbatm_init_channel(&instance->tx_channel); - tasklet_setup(&instance->rx_channel.tasklet, usbatm_rx_process); - tasklet_setup(&instance->tx_channel.tasklet, usbatm_tx_process); + INIT_WORK(&instance->rx_channel.work, usbatm_rx_process); + INIT_WORK(&instance->tx_channel.work, usbatm_tx_process); instance->rx_channel.stride = ATM_CELL_SIZE + driver->rx_padding; instance->tx_channel.stride = ATM_CELL_SIZE + driver->tx_padding; instance->rx_channel.usbatm = instance->tx_channel.usbatm = instance; @@ -1231,8 +1232,8 @@ void usbatm_usb_disconnect(struct usb_interface *intf) vcc_release_async(vcc_data->vcc, -EPIPE); mutex_unlock(&instance->serialize); - tasklet_disable(&instance->rx_channel.tasklet); - tasklet_disable(&instance->tx_channel.tasklet); + disable_work_sync(&instance->rx_channel.work); + disable_work_sync(&instance->tx_channel.work); for (i = 0; i < num_rcv_urbs + num_snd_urbs; i++) usb_kill_urb(instance->urbs[i]); @@ -1245,8 +1246,8 @@ void usbatm_usb_disconnect(struct usb_interface *intf) INIT_LIST_HEAD(&instance->rx_channel.list); INIT_LIST_HEAD(&instance->tx_channel.list); - tasklet_enable(&instance->rx_channel.tasklet); - tasklet_enable(&instance->tx_channel.tasklet); + enable_and_queue_work(system_bh_wq, &instance->rx_channel.work); + enable_and_queue_work(system_bh_wq, &instance->tx_channel.work); if (instance->atm_dev && instance->driver->atm_stop) instance->driver->atm_stop(instance, instance->atm_dev); diff --git a/drivers/usb/atm/usbatm.h b/drivers/usb/atm/usbatm.h index d96658e2e209..3452f8c2e1e5 100644 --- a/drivers/usb/atm/usbatm.h +++ b/drivers/usb/atm/usbatm.h @@ -21,6 +21,7 @@ #include <linux/usb.h> #include <linux/mutex.h> #include <linux/ratelimit.h> +#include <linux/workqueue.h> /* #define VERBOSE_DEBUG @@ -109,7 +110,7 @@ struct usbatm_channel { unsigned int packet_size; /* endpoint maxpacket */ spinlock_t lock; struct list_head list; - struct tasklet_struct tasklet; + struct work_struct work; struct timer_list delay; struct usbatm_data *usbatm; }; diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c index c0e005670d67..b31d84b02055 100644 --- a/drivers/usb/core/hcd.c +++ b/drivers/usb/core/hcd.c @@ -37,6 +37,7 @@ #include <linux/usb.h> #include <linux/usb/hcd.h> #include <linux/usb/otg.h> +#include <linux/workqueue.h> #include "usb.h" #include "phy.h" @@ -1664,8 +1665,7 @@ static void __usb_hcd_giveback_urb(struct urb *urb) static void usb_giveback_urb_bh(struct work_struct *work) { - struct giveback_urb_bh *bh = - container_of(work, struct giveback_urb_bh, bh); + struct giveback_urb_bh *bh = from_work(bh, work, bh); struct list_head local_list; spin_lock_irq(&bh->lock); diff --git a/drivers/usb/gadget/udc/fsl_qe_udc.c b/drivers/usb/gadget/udc/fsl_qe_udc.c index 4e88681a79b6..ae29d946a972 100644 --- a/drivers/usb/gadget/udc/fsl_qe_udc.c +++ b/drivers/usb/gadget/udc/fsl_qe_udc.c @@ -35,6 +35,7 @@ #include <linux/usb/ch9.h> #include <linux/usb/gadget.h> #include <linux/usb/otg.h> +#include <linux/workqueue.h> #include <soc/fsl/qe/qe.h> #include <asm/cpm.h> #include <asm/dma.h> @@ -930,9 +931,9 @@ static int qe_ep_rxframe_handle(struct qe_ep *ep) return 0; } -static void ep_rx_tasklet(struct tasklet_struct *t) +static void ep_rx_work(struct work_struct *t) { - struct qe_udc *udc = from_tasklet(udc, t, rx_tasklet); + struct qe_udc *udc = from_work(udc, t, rx_work); struct qe_ep *ep; struct qe_frame *pframe; struct qe_bd __iomem *bd; @@ -945,9 +946,9 @@ static void ep_rx_tasklet(struct tasklet_struct *t) for (i = 1; i < USB_MAX_ENDPOINTS; i++) { ep = &udc->eps[i]; - if (ep->dir == USB_DIR_IN || ep->enable_tasklet == 0) { + if (ep->dir == USB_DIR_IN || ep->enable_work == 0) { dev_dbg(udc->dev, - "This is a transmit ep or disable tasklet!\n"); + "This is a transmit ep or disable work!\n"); continue; } @@ -1012,7 +1013,7 @@ static void ep_rx_tasklet(struct tasklet_struct *t) if (ep->localnack) ep_recycle_rxbds(ep); - ep->enable_tasklet = 0; + ep->enable_work = 0; } /* for i=1 */ spin_unlock_irqrestore(&udc->lock, flags); @@ -1057,8 +1058,8 @@ static int qe_ep_rx(struct qe_ep *ep) return 0; } - tasklet_schedule(&udc->rx_tasklet); - ep->enable_tasklet = 1; + queue_work(system_bh_wq, &udc->rx_work); + ep->enable_work = 1; return 0; } @@ -2559,7 +2560,7 @@ static int qe_udc_probe(struct platform_device *ofdev) DMA_TO_DEVICE); } - tasklet_setup(&udc->rx_tasklet, ep_rx_tasklet); + INIT_WORK(&udc->rx_work, ep_rx_work); /* request irq and disable DR */ udc->usb_irq = irq_of_parse_and_map(np, 0); if (!udc->usb_irq) { @@ -2636,7 +2637,7 @@ static void qe_udc_remove(struct platform_device *ofdev) usb_del_gadget_udc(&udc->gadget); udc->done = &done; - tasklet_disable(&udc->rx_tasklet); + disable_work_sync(&udc->rx_work); if (udc->nullmap) { dma_unmap_single(udc->gadget.dev.parent, @@ -2671,7 +2672,7 @@ static void qe_udc_remove(struct platform_device *ofdev) free_irq(udc->usb_irq, udc); irq_dispose_mapping(udc->usb_irq); - tasklet_kill(&udc->rx_tasklet); + cancel_work_sync(&udc->rx_work); iounmap(udc->usb_regs); diff --git a/drivers/usb/gadget/udc/fsl_qe_udc.h b/drivers/usb/gadget/udc/fsl_qe_udc.h index 53ca0ff7c2cb..1de87c318460 100644 --- a/drivers/usb/gadget/udc/fsl_qe_udc.h +++ b/drivers/usb/gadget/udc/fsl_qe_udc.h @@ -293,7 +293,7 @@ struct qe_ep { u8 init; u8 already_seen; - u8 enable_tasklet; + u8 enable_work; u8 setup_stage; u32 last_io; /* timestamp */ @@ -353,7 +353,7 @@ struct qe_udc { unsigned int usb_irq; struct usb_ctlr __iomem *usb_regs; - struct tasklet_struct rx_tasklet; + struct work_struct rx_work; struct completion *done; /* to make sure release() is done */ }; diff --git a/drivers/usb/host/ehci-sched.c b/drivers/usb/host/ehci-sched.c index 7e834587e7de..54f3bd6298e6 100644 --- a/drivers/usb/host/ehci-sched.c +++ b/drivers/usb/host/ehci-sched.c @@ -682,7 +682,7 @@ static void start_unlink_intr(struct ehci_hcd *ehci, struct ehci_qh *qh) /* * It is common only one intr URB is scheduled on one qh, and - * given complete() is run in tasklet context, introduce a bit + * given complete() is run in task context, introduce a bit * delay to avoid unlink qh too early. */ static void start_unlink_intr_wait(struct ehci_hcd *ehci, diff --git a/drivers/usb/host/fhci-hcd.c b/drivers/usb/host/fhci-hcd.c index 9a1b5224f239..5358bb688acb 100644 --- a/drivers/usb/host/fhci-hcd.c +++ b/drivers/usb/host/fhci-hcd.c @@ -211,8 +211,7 @@ static int fhci_mem_init(struct fhci_hcd *fhci) INIT_LIST_HEAD(&fhci->empty_tds); /* initialize work queue to handle done list */ - fhci_tasklet.data = (unsigned long)fhci; - fhci->process_done_task = &fhci_tasklet; + INIT_WORK(&fhci->process_done_task, process_done_list); for (i = 0; i < MAX_TDS; i++) { struct td *td; diff --git a/drivers/usb/host/fhci-sched.c b/drivers/usb/host/fhci-sched.c index a45ede80edfc..9033cce28014 100644 --- a/drivers/usb/host/fhci-sched.c +++ b/drivers/usb/host/fhci-sched.c @@ -628,13 +628,13 @@ irqreturn_t fhci_irq(struct usb_hcd *hcd) * is process_del_list(),which unlinks URBs by scanning EDs,instead of scanning * the (re-reversed) done list as this does. */ -static void process_done_list(unsigned long data) +static void process_done_list(struct work_struct *t) { struct urb *urb; struct ed *ed; struct td *td; struct urb_priv *urb_priv; - struct fhci_hcd *fhci = (struct fhci_hcd *)data; + struct fhci_hcd *fhci = from_work(fhci, t, process_done_task); disable_irq(fhci->timer->irq); disable_irq(fhci_to_hcd(fhci)->irq); @@ -677,13 +677,13 @@ static void process_done_list(unsigned long data) enable_irq(fhci_to_hcd(fhci)->irq); } -DECLARE_TASKLET_OLD(fhci_tasklet, process_done_list); +DECLARE_WORK(fhci_work, process_done_list); /* transfer complted callback */ u32 fhci_transfer_confirm_callback(struct fhci_hcd *fhci) { - if (!fhci->process_done_task->state) - tasklet_schedule(fhci->process_done_task); + if (!fhci->process_done_task) + queue_work(system_bh_wq, fhci->process_done_task); return 0; } diff --git a/drivers/usb/host/fhci.h b/drivers/usb/host/fhci.h index 1f57b0989485..7cd613762249 100644 --- a/drivers/usb/host/fhci.h +++ b/drivers/usb/host/fhci.h @@ -24,6 +24,7 @@ #include <linux/usb.h> #include <linux/usb/hcd.h> #include <linux/gpio/consumer.h> +#include <linux/workqueue.h> #include <soc/fsl/qe/qe.h> #include <soc/fsl/qe/immap_qe.h> @@ -254,7 +255,7 @@ struct fhci_hcd { struct virtual_root_hub *vroot_hub; /* the virtual root hub */ int active_urbs; struct fhci_controller_list *hc_list; - struct tasklet_struct *process_done_task; /* tasklet for done list */ + struct work_struct *process_done_task; /* work for done list */ struct list_head empty_eds; struct list_head empty_tds; @@ -549,7 +550,7 @@ void fhci_init_ep_registers(struct fhci_usb *usb, void fhci_ep0_free(struct fhci_usb *usb); /* fhci-sched.c */ -extern struct tasklet_struct fhci_tasklet; +extern struct work_struct fhci_work; void fhci_transaction_confirm(struct fhci_usb *usb, struct packet *pkt); void fhci_flush_all_transmissions(struct fhci_usb *usb); void fhci_schedule_transactions(struct fhci_usb *usb); diff --git a/drivers/usb/host/xhci-dbgcap.h b/drivers/usb/host/xhci-dbgcap.h index 92661b555c2a..0cd57c479fd7 100644 --- a/drivers/usb/host/xhci-dbgcap.h +++ b/drivers/usb/host/xhci-dbgcap.h @@ -11,6 +11,7 @@ #include <linux/tty.h> #include <linux/kfifo.h> +#include <linux/workqueue.h> struct dbc_regs { __le32 capability; @@ -107,7 +108,7 @@ struct dbc_port { struct list_head read_pool; struct list_head read_queue; unsigned int n_read; - struct tasklet_struct push; + struct work_struct push; struct list_head write_pool; struct kfifo write_fifo; diff --git a/drivers/usb/host/xhci-dbgtty.c b/drivers/usb/host/xhci-dbgtty.c index b74e98e94393..dec2280b4ae9 100644 --- a/drivers/usb/host/xhci-dbgtty.c +++ b/drivers/usb/host/xhci-dbgtty.c @@ -11,6 +11,7 @@ #include <linux/tty.h> #include <linux/tty_flip.h> #include <linux/idr.h> +#include <linux/workqueue.h> #include "xhci.h" #include "xhci-dbgcap.h" @@ -108,7 +109,7 @@ dbc_read_complete(struct xhci_dbc *dbc, struct dbc_request *req) spin_lock_irqsave(&port->port_lock, flags); list_add_tail(&req->list_pool, &port->read_queue); - tasklet_schedule(&port->push); + queue_work(system_bh_wq, &port->push); spin_unlock_irqrestore(&port->port_lock, flags); } @@ -278,7 +279,7 @@ static void dbc_tty_unthrottle(struct tty_struct *tty) unsigned long flags; spin_lock_irqsave(&port->port_lock, flags); - tasklet_schedule(&port->push); + queue_work(system_bh_wq, &port->push); spin_unlock_irqrestore(&port->port_lock, flags); } @@ -294,14 +295,14 @@ static const struct tty_operations dbc_tty_ops = { .unthrottle = dbc_tty_unthrottle, }; -static void dbc_rx_push(struct tasklet_struct *t) +static void dbc_rx_push(struct work_struct *t) { struct dbc_request *req; struct tty_struct *tty; unsigned long flags; bool do_push = false; bool disconnect = false; - struct dbc_port *port = from_tasklet(port, t, push); + struct dbc_port *port = from_work(port, t, push); struct list_head *queue = &port->read_queue; spin_lock_irqsave(&port->port_lock, flags); @@ -355,7 +356,7 @@ static void dbc_rx_push(struct tasklet_struct *t) if (!list_empty(queue) && tty) { if (!tty_throttled(tty)) { if (do_push) - tasklet_schedule(&port->push); + queue_work(system_bh_wq, &port->push); else pr_warn("ttyDBC0: RX not scheduled?\n"); } @@ -388,7 +389,7 @@ xhci_dbc_tty_init_port(struct xhci_dbc *dbc, struct dbc_port *port) { tty_port_init(&port->port); spin_lock_init(&port->port_lock); - tasklet_setup(&port->push, dbc_rx_push); + INIT_WORK(&port->push, dbc_rx_push); INIT_LIST_HEAD(&port->read_pool); INIT_LIST_HEAD(&port->read_queue); INIT_LIST_HEAD(&port->write_pool); @@ -400,7 +401,7 @@ xhci_dbc_tty_init_port(struct xhci_dbc *dbc, struct dbc_port *port) static void xhci_dbc_tty_exit_port(struct dbc_port *port) { - tasklet_kill(&port->push); + cancel_work_sync(&port->push); tty_port_destroy(&port->port); } diff --git a/include/linux/usb/cdc_ncm.h b/include/linux/usb/cdc_ncm.h index 2d207cb4837d..8775580852f9 100644 --- a/include/linux/usb/cdc_ncm.h +++ b/include/linux/usb/cdc_ncm.h @@ -96,7 +96,7 @@ struct cdc_ncm_ctx { struct usb_cdc_ncm_ntb_parameters ncm_parm; struct hrtimer tx_timer; - struct tasklet_struct bh; + struct work_struct bh; struct usbnet *dev; diff --git a/include/linux/usb/usbnet.h b/include/linux/usb/usbnet.h index 9f08a584d707..522c533a966b 100644 --- a/include/linux/usb/usbnet.h +++ b/include/linux/usb/usbnet.h @@ -58,7 +58,7 @@ struct usbnet { unsigned interrupt_count; struct mutex interrupt_mutex; struct usb_anchor deferred; - struct tasklet_struct bh; + struct work_struct bh; struct work_struct kevent; unsigned long flags; -- 2.17.1
