This is a note to let you know that I've just added the patch titled can: bcm: switch timer to HRTIMER_MODE_SOFT and remove hrtimer_tasklet to the 4.19-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: can-bcm-switch-timer-to-hrtimer_mode_soft-and-remove-hrtimer_tasklet.patch and it can be found in the queue-4.19 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From bf74aa86e111aa3b2fbb25db37e3a3fab71b5b68 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Date: Mon, 12 Aug 2019 14:57:14 +0200 Subject: can: bcm: switch timer to HRTIMER_MODE_SOFT and remove hrtimer_tasklet From: Thomas Gleixner <tglx@xxxxxxxxxxxxx> commit bf74aa86e111aa3b2fbb25db37e3a3fab71b5b68 upstream. This patch switches the timer to HRTIMER_MODE_SOFT, which executed the timer callback in softirq context and removes the hrtimer_tasklet. Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Signed-off-by: Anna-Maria Gleixner <anna-maria@xxxxxxxxxxxxx> Acked-by: Oliver Hartkopp <socketcan@xxxxxxxxxxxx> Signed-off-by: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx> Signed-off-by: Ziyang Xuan <william.xuanziyang@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/can/bcm.c | 156 +++++++++++++++++++--------------------------------------- 1 file changed, 52 insertions(+), 104 deletions(-) --- a/net/can/bcm.c +++ b/net/can/bcm.c @@ -105,7 +105,6 @@ struct bcm_op { unsigned long frames_abs, frames_filtered; struct bcm_timeval ival1, ival2; struct hrtimer timer, thrtimer; - struct tasklet_struct tsklet, thrtsklet; ktime_t rx_stamp, kt_ival1, kt_ival2, kt_lastmsg; int rx_ifindex; int cfsiz; @@ -374,25 +373,34 @@ static void bcm_send_to_user(struct bcm_ } } -static void bcm_tx_start_timer(struct bcm_op *op) +static bool bcm_tx_set_expiry(struct bcm_op *op, struct hrtimer *hrt) { + ktime_t ival; + if (op->kt_ival1 && op->count) - hrtimer_start(&op->timer, - ktime_add(ktime_get(), op->kt_ival1), - HRTIMER_MODE_ABS); + ival = op->kt_ival1; else if (op->kt_ival2) - hrtimer_start(&op->timer, - ktime_add(ktime_get(), op->kt_ival2), - HRTIMER_MODE_ABS); + ival = op->kt_ival2; + else + return false; + + hrtimer_set_expires(hrt, ktime_add(ktime_get(), ival)); + return true; } -static void bcm_tx_timeout_tsklet(unsigned long data) +static void bcm_tx_start_timer(struct bcm_op *op) { - struct bcm_op *op = (struct bcm_op *)data; + if (bcm_tx_set_expiry(op, &op->timer)) + hrtimer_start_expires(&op->timer, HRTIMER_MODE_ABS_SOFT); +} + +/* bcm_tx_timeout_handler - performs cyclic CAN frame transmissions */ +static enum hrtimer_restart bcm_tx_timeout_handler(struct hrtimer *hrtimer) +{ + struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer); struct bcm_msg_head msg_head; if (op->kt_ival1 && (op->count > 0)) { - op->count--; if (!op->count && (op->flags & TX_COUNTEVT)) { @@ -410,22 +418,12 @@ static void bcm_tx_timeout_tsklet(unsign } bcm_can_tx(op); - } else if (op->kt_ival2) + } else if (op->kt_ival2) { bcm_can_tx(op); + } - bcm_tx_start_timer(op); -} - -/* - * bcm_tx_timeout_handler - performs cyclic CAN frame transmissions - */ -static enum hrtimer_restart bcm_tx_timeout_handler(struct hrtimer *hrtimer) -{ - struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer); - - tasklet_schedule(&op->tsklet); - - return HRTIMER_NORESTART; + return bcm_tx_set_expiry(op, &op->timer) ? + HRTIMER_RESTART : HRTIMER_NORESTART; } /* @@ -492,7 +490,7 @@ static void bcm_rx_update_and_send(struc /* do not send the saved data - only start throttle timer */ hrtimer_start(&op->thrtimer, ktime_add(op->kt_lastmsg, op->kt_ival2), - HRTIMER_MODE_ABS); + HRTIMER_MODE_ABS_SOFT); return; } @@ -551,14 +549,21 @@ static void bcm_rx_starttimer(struct bcm return; if (op->kt_ival1) - hrtimer_start(&op->timer, op->kt_ival1, HRTIMER_MODE_REL); + hrtimer_start(&op->timer, op->kt_ival1, HRTIMER_MODE_REL_SOFT); } -static void bcm_rx_timeout_tsklet(unsigned long data) +/* bcm_rx_timeout_handler - when the (cyclic) CAN frame reception timed out */ +static enum hrtimer_restart bcm_rx_timeout_handler(struct hrtimer *hrtimer) { - struct bcm_op *op = (struct bcm_op *)data; + struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer); struct bcm_msg_head msg_head; + /* if user wants to be informed, when cyclic CAN-Messages come back */ + if ((op->flags & RX_ANNOUNCE_RESUME) && op->last_frames) { + /* clear received CAN frames to indicate 'nothing received' */ + memset(op->last_frames, 0, op->nframes * op->cfsiz); + } + /* create notification to user */ memset(&msg_head, 0, sizeof(msg_head)); msg_head.opcode = RX_TIMEOUT; @@ -570,25 +575,6 @@ static void bcm_rx_timeout_tsklet(unsign msg_head.nframes = 0; bcm_send_to_user(op, &msg_head, NULL, 0); -} - -/* - * bcm_rx_timeout_handler - when the (cyclic) CAN frame reception timed out - */ -static enum hrtimer_restart bcm_rx_timeout_handler(struct hrtimer *hrtimer) -{ - struct bcm_op *op = container_of(hrtimer, struct bcm_op, timer); - - /* schedule before NET_RX_SOFTIRQ */ - tasklet_hi_schedule(&op->tsklet); - - /* no restart of the timer is done here! */ - - /* if user wants to be informed, when cyclic CAN-Messages come back */ - if ((op->flags & RX_ANNOUNCE_RESUME) && op->last_frames) { - /* clear received CAN frames to indicate 'nothing received' */ - memset(op->last_frames, 0, op->nframes * op->cfsiz); - } return HRTIMER_NORESTART; } @@ -596,14 +582,12 @@ static enum hrtimer_restart bcm_rx_timeo /* * bcm_rx_do_flush - helper for bcm_rx_thr_flush */ -static inline int bcm_rx_do_flush(struct bcm_op *op, int update, - unsigned int index) +static inline int bcm_rx_do_flush(struct bcm_op *op, unsigned int index) { struct canfd_frame *lcf = op->last_frames + op->cfsiz * index; if ((op->last_frames) && (lcf->flags & RX_THR)) { - if (update) - bcm_rx_changed(op, lcf); + bcm_rx_changed(op, lcf); return 1; } return 0; @@ -611,11 +595,8 @@ static inline int bcm_rx_do_flush(struct /* * bcm_rx_thr_flush - Check for throttled data and send it to the userspace - * - * update == 0 : just check if throttled data is available (any irq context) - * update == 1 : check and send throttled data to userspace (soft_irq context) */ -static int bcm_rx_thr_flush(struct bcm_op *op, int update) +static int bcm_rx_thr_flush(struct bcm_op *op) { int updated = 0; @@ -624,24 +605,16 @@ static int bcm_rx_thr_flush(struct bcm_o /* for MUX filter we start at index 1 */ for (i = 1; i < op->nframes; i++) - updated += bcm_rx_do_flush(op, update, i); + updated += bcm_rx_do_flush(op, i); } else { /* for RX_FILTER_ID and simple filter */ - updated += bcm_rx_do_flush(op, update, 0); + updated += bcm_rx_do_flush(op, 0); } return updated; } -static void bcm_rx_thr_tsklet(unsigned long data) -{ - struct bcm_op *op = (struct bcm_op *)data; - - /* push the changed data to the userspace */ - bcm_rx_thr_flush(op, 1); -} - /* * bcm_rx_thr_handler - the time for blocked content updates is over now: * Check for throttled data and send it to the userspace @@ -650,9 +623,7 @@ static enum hrtimer_restart bcm_rx_thr_h { struct bcm_op *op = container_of(hrtimer, struct bcm_op, thrtimer); - tasklet_schedule(&op->thrtsklet); - - if (bcm_rx_thr_flush(op, 0)) { + if (bcm_rx_thr_flush(op)) { hrtimer_forward(hrtimer, ktime_get(), op->kt_ival2); return HRTIMER_RESTART; } else { @@ -748,23 +719,8 @@ static struct bcm_op *bcm_find_op(struct static void bcm_remove_op(struct bcm_op *op) { - if (op->tsklet.func) { - while (test_bit(TASKLET_STATE_SCHED, &op->tsklet.state) || - test_bit(TASKLET_STATE_RUN, &op->tsklet.state) || - hrtimer_active(&op->timer)) { - hrtimer_cancel(&op->timer); - tasklet_kill(&op->tsklet); - } - } - - if (op->thrtsklet.func) { - while (test_bit(TASKLET_STATE_SCHED, &op->thrtsklet.state) || - test_bit(TASKLET_STATE_RUN, &op->thrtsklet.state) || - hrtimer_active(&op->thrtimer)) { - hrtimer_cancel(&op->thrtimer); - tasklet_kill(&op->thrtsklet); - } - } + hrtimer_cancel(&op->timer); + hrtimer_cancel(&op->thrtimer); if ((op->frames) && (op->frames != &op->sframe)) kfree(op->frames); @@ -998,15 +954,13 @@ static int bcm_tx_setup(struct bcm_msg_h op->ifindex = ifindex; /* initialize uninitialized (kzalloc) structure */ - hrtimer_init(&op->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); + hrtimer_init(&op->timer, CLOCK_MONOTONIC, + HRTIMER_MODE_REL_SOFT); op->timer.function = bcm_tx_timeout_handler; - /* initialize tasklet for tx countevent notification */ - tasklet_init(&op->tsklet, bcm_tx_timeout_tsklet, - (unsigned long) op); - /* currently unused in tx_ops */ - hrtimer_init(&op->thrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); + hrtimer_init(&op->thrtimer, CLOCK_MONOTONIC, + HRTIMER_MODE_REL_SOFT); /* add this bcm_op to the list of the tx_ops */ list_add(&op->list, &bo->tx_ops); @@ -1175,20 +1129,14 @@ static int bcm_rx_setup(struct bcm_msg_h op->rx_ifindex = ifindex; /* initialize uninitialized (kzalloc) structure */ - hrtimer_init(&op->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); + hrtimer_init(&op->timer, CLOCK_MONOTONIC, + HRTIMER_MODE_REL_SOFT); op->timer.function = bcm_rx_timeout_handler; - /* initialize tasklet for rx timeout notification */ - tasklet_init(&op->tsklet, bcm_rx_timeout_tsklet, - (unsigned long) op); - - hrtimer_init(&op->thrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); + hrtimer_init(&op->thrtimer, CLOCK_MONOTONIC, + HRTIMER_MODE_REL_SOFT); op->thrtimer.function = bcm_rx_thr_handler; - /* initialize tasklet for rx throttle handling */ - tasklet_init(&op->thrtsklet, bcm_rx_thr_tsklet, - (unsigned long) op); - /* add this bcm_op to the list of the rx_ops */ list_add(&op->list, &bo->rx_ops); @@ -1234,12 +1182,12 @@ static int bcm_rx_setup(struct bcm_msg_h */ op->kt_lastmsg = 0; hrtimer_cancel(&op->thrtimer); - bcm_rx_thr_flush(op, 1); + bcm_rx_thr_flush(op); } if ((op->flags & STARTTIMER) && op->kt_ival1) hrtimer_start(&op->timer, op->kt_ival1, - HRTIMER_MODE_REL); + HRTIMER_MODE_REL_SOFT); } /* now we can register for can_ids, if we added a new bcm_op */ Patches currently in stable-queue which might be from tglx@xxxxxxxxxxxxx are queue-4.19/can-bcm-switch-timer-to-hrtimer_mode_soft-and-remove-hrtimer_tasklet.patch