From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Gleixner Subject: [patch V3 12/20] powerpc/ps3: Convert half completion to rcuwait Date: Sat, 21 Mar 2020 12:25:56 +0100 Message-ID: <20200321113241.930037873@linutronix.de> References: <20200321112544.878032781@linutronix.de> Mime-Version: 1.0 Content-Transfer-Encoding: 8-bit Return-path: Sender: linux-ia64-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="us-ascii" To: LKML Cc: Peter Zijlstra , Ingo Molnar , Sebastian Siewior , Linus Torvalds , Joel Fernandes , Oleg Nesterov , Davidlohr Bueso , Michael Ellerman , Arnd Bergmann , Geoff Levand , linuxppc-dev@lists.ozlabs.org, Logan Gunthorpe , Bjorn Helgaas , Kurt Schwemmer , linux-pci@vger.kernel.org, Greg Kroah-Hartman , Felipe Balbi , linux-usb@vger.kernel.org, Kalle Valo , "David S. Miller" From: Thomas Gleixner The PS3 notification interrupt and kthread use a hacked up completion to communicate. Since we're wanting to change the completion implementation and this is abuse anyway, replace it with a simple rcuwait since there is only ever the one waiter. AFAICT the kthread uses TASK_INTERRUPTIBLE to not increase loadavg, kthreads cannot receive signals by default and this one doesn't look different. Use TASK_IDLE instead. Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Thomas Gleixner Cc: Michael Ellerman Cc: Arnd Bergmann Cc: Geoff Levand Cc: linuxppc-dev@lists.ozlabs.org --- V3: Folded the init fix from bigeasy V2: New patch to avoid the magic completion wait variant --- arch/powerpc/platforms/ps3/device-init.c | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) --- a/arch/powerpc/platforms/ps3/device-init.c +++ b/arch/powerpc/platforms/ps3/device-init.c @@ -13,6 +13,7 @@ #include #include #include +#include #include #include @@ -670,7 +671,8 @@ struct ps3_notification_device { spinlock_t lock; u64 tag; u64 lv1_status; - struct completion done; + struct rcuwait wait; + bool done; }; enum ps3_notify_type { @@ -712,7 +714,8 @@ static irqreturn_t ps3_notification_inte pr_debug("%s:%u: completed, status 0x%llx\n", __func__, __LINE__, status); dev->lv1_status = status; - complete(&dev->done); + dev->done = true; + rcuwait_wake_up(&dev->wait); } spin_unlock(&dev->lock); return IRQ_HANDLED; @@ -725,12 +728,12 @@ static int ps3_notification_read_write(s unsigned long flags; int res; - init_completion(&dev->done); spin_lock_irqsave(&dev->lock, flags); res = write ? lv1_storage_write(dev->sbd.dev_id, 0, 0, 1, 0, lpar, &dev->tag) : lv1_storage_read(dev->sbd.dev_id, 0, 0, 1, 0, lpar, &dev->tag); + dev->done = false; spin_unlock_irqrestore(&dev->lock, flags); if (res) { pr_err("%s:%u: %s failed %d\n", __func__, __LINE__, op, res); @@ -738,14 +741,10 @@ static int ps3_notification_read_write(s } pr_debug("%s:%u: notification %s issued\n", __func__, __LINE__, op); - res = wait_event_interruptible(dev->done.wait, - dev->done.done || kthread_should_stop()); + rcuwait_wait_event(&dev->wait, dev->done || kthread_should_stop(), TASK_IDLE); + if (kthread_should_stop()) res = -EINTR; - if (res) { - pr_debug("%s:%u: interrupted %s\n", __func__, __LINE__, op); - return res; - } if (dev->lv1_status) { pr_err("%s:%u: %s not completed, status 0x%llx\n", __func__, @@ -810,6 +809,7 @@ static int ps3_probe_thread(void *data) } spin_lock_init(&dev.lock); + rcuwait_init(&dev.wait); res = request_irq(irq, ps3_notification_interrupt, 0, "ps3_notification", &dev);