From patchwork Thu Dec 10 19:26:02 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thomas Gleixner X-Patchwork-Id: 11967477 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 36433C1B0D9 for ; Fri, 11 Dec 2020 08:16:21 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id D640123E56 for ; Fri, 11 Dec 2020 08:16:20 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D640123E56 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linutronix.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id F2C296EC88; Fri, 11 Dec 2020 08:16:08 +0000 (UTC) Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) by gabe.freedesktop.org (Postfix) with ESMTPS id C28CC6EB26; Thu, 10 Dec 2020 19:42:48 +0000 (UTC) Message-Id: <20201210194045.157601122@linutronix.de> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1607629367; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: references:references; bh=RU1bu/2cEIaQZD4XBTa1ORm36AT2+9xoAT9okJ4RH1c=; b=AhYGZMH5Lll3k86M+Mw+u/CMXrFP+z5OweedDSPLrQC7zMl71ejfF6LXNXRZTGD8kmOuJe qS19XHZYRwS6BqhVuvnoRC1T4ttKWNuaoSyT3BgYYN1BzFtZlPcOz+YQKy/43th5Y90u/R X6B6cmkRFkndNRXwbx2PLjfkgaDXN0K9HLJvSEGYF2Mwu+bniCBmPPPJ7kblKM0absRSol Xu6RJgcDTReN71V4H+Nn1MY4+vbA65bMSFOyl/jldJBTen7poJfNR1wRX6XEMJPR917pl1 k5XFjcYwY2tULG78ylPnHOTKCe4dKJGK7v6roca6SRSYcgOrtkVCsvBrRQWZhw== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1607629367; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: references:references; bh=RU1bu/2cEIaQZD4XBTa1ORm36AT2+9xoAT9okJ4RH1c=; b=XdjqOHU/CtrxmjSRt3J35g254e3xJTlyAPxkG/hnQfineDJae9yPVorBnqLmfzdojIT+AV RtH7kedwWF+OweDQ== Date: Thu, 10 Dec 2020 20:26:02 +0100 From: Thomas Gleixner To: LKML Subject: [patch 26/30] xen/events: Use immediate affinity setting References: <20201210192536.118432146@linutronix.de> MIME-Version: 1.0 X-Mailman-Approved-At: Fri, 11 Dec 2020 08:16:07 +0000 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , Karthikeyan Mitran , Peter Zijlstra , Catalin Marinas , dri-devel@lists.freedesktop.org, Chris Wilson , "James E.J. Bottomley" , Saeed Mahameed , netdev@vger.kernel.org, Jakub Kicinski , Will Deacon , Michal Simek , linux-s390@vger.kernel.org, afzal mohammed , Stefano Stabellini , Dave Jiang , Leon Romanovsky , linux-rdma@vger.kernel.org, Marc Zyngier , Helge Deller , Russell King , Christian Borntraeger , linux-pci@vger.kernel.org, xen-devel@lists.xenproject.org, Heiko Carstens , Wambui Karuga , Allen Hubbe , David Airlie , linux-gpio@vger.kernel.org, Lorenzo Pieralisi , Rodrigo Vivi , Bjorn Helgaas , Boris Ostrovsky , linux-arm-kernel@lists.infradead.org, Juergen Gross , Tvrtko Ursulin , Lee Jones , linux-parisc@vger.kernel.org, Pankaj Bharadiya , Hou Zhiqiang , Tariq Toukan , Jon Mason , linux-ntb@googlegroups.com, intel-gfx@lists.freedesktop.org, "David S. Miller" Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" There is absolutely no reason to mimic the x86 deferred affinity setting. This mechanism is required to handle the hardware induced issues of IO/APIC and MSI and is not in use when the interrupts are remapped. XEN does not need this and can simply change the affinity from the calling context. The core code invokes this with the interrupt descriptor lock held so it is fully serialized against any other operation. Mark the interrupts with IRQ_MOVE_PCNTXT to disable the deferred affinity setting. The conditional mask/unmask operation is already handled in xen_rebind_evtchn_to_cpu(). This makes XEN on x86 use the same mechanics as on e.g. ARM64 where deferred affinity setting is not required and not implemented and the code path in the ack functions is compiled out. Signed-off-by: Thomas Gleixner Cc: Boris Ostrovsky Cc: Juergen Gross Cc: Stefano Stabellini Cc: xen-devel@lists.xenproject.org --- drivers/xen/events/events_base.c | 35 +++++++++-------------------------- 1 file changed, 9 insertions(+), 26 deletions(-) --- a/drivers/xen/events/events_base.c +++ b/drivers/xen/events/events_base.c @@ -628,6 +628,11 @@ static void xen_irq_init(unsigned irq) info->refcnt = -1; set_info_for_irq(irq, info); + /* + * Interrupt affinity setting can be immediate. No point + * in delaying it until an interrupt is handled. + */ + irq_set_status_flags(irq, IRQ_MOVE_PCNTXT); INIT_LIST_HEAD(&info->eoi_list); list_add_tail(&info->list, &xen_irq_list_head); @@ -739,18 +744,7 @@ static void eoi_pirq(struct irq_data *da if (!VALID_EVTCHN(evtchn)) return; - if (unlikely(irqd_is_setaffinity_pending(data)) && - likely(!irqd_irq_disabled(data))) { - int masked = test_and_set_mask(evtchn); - - clear_evtchn(evtchn); - - irq_move_masked_irq(data); - - if (!masked) - unmask_evtchn(evtchn); - } else - clear_evtchn(evtchn); + clear_evtchn(evtchn); if (pirq_needs_eoi(data->irq)) { rc = HYPERVISOR_physdev_op(PHYSDEVOP_eoi, &eoi); @@ -1641,7 +1635,6 @@ void rebind_evtchn_irq(evtchn_port_t evt mutex_unlock(&irq_mapping_update_lock); bind_evtchn_to_cpu(evtchn, info->cpu); - /* This will be deferred until interrupt is processed */ irq_set_affinity(irq, cpumask_of(info->cpu)); /* Unmask the event channel. */ @@ -1688,8 +1681,9 @@ static int set_affinity_irq(struct irq_d bool force) { unsigned tcpu = cpumask_first_and(dest, cpu_online_mask); - int ret = xen_rebind_evtchn_to_cpu(evtchn_from_irq(data->irq), tcpu); + int ret; + ret = xen_rebind_evtchn_to_cpu(evtchn_from_irq(data->irq), tcpu); if (!ret) irq_data_update_effective_affinity(data, cpumask_of(tcpu)); @@ -1719,18 +1713,7 @@ static void ack_dynirq(struct irq_data * if (!VALID_EVTCHN(evtchn)) return; - if (unlikely(irqd_is_setaffinity_pending(data)) && - likely(!irqd_irq_disabled(data))) { - int masked = test_and_set_mask(evtchn); - - clear_evtchn(evtchn); - - irq_move_masked_irq(data); - - if (!masked) - unmask_evtchn(evtchn); - } else - clear_evtchn(evtchn); + clear_evtchn(evtchn); } static void mask_ack_dynirq(struct irq_data *data)