Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933947AbbKSJLC (ORCPT ); Thu, 19 Nov 2015 04:11:02 -0500 Received: from mx2.suse.de ([195.135.220.15]:36086 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933685AbbKSJKt (ORCPT ); Thu, 19 Nov 2015 04:10:49 -0500 Subject: Re: [PATCH v2] xen/events: Always allocate legacy interrupts on PV guests To: Boris Ostrovsky , konrad.wilk@oracle.com, david.vrabel@citrix.com, linux@arm.linux.org.uk References: <1447870445-17199-1-git-send-email-boris.ostrovsky@oracle.com> Cc: stefano.stabellini@citrix.com, tglx@linutronix.de, vkuznets@redhat.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, xen-devel@lists.xen.org From: Juergen Gross Message-ID: <564D9216.7010307@suse.com> Date: Thu, 19 Nov 2015 10:10:46 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.3.0 MIME-Version: 1.0 In-Reply-To: <1447870445-17199-1-git-send-email-boris.ostrovsky@oracle.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2360 Lines: 76 On 18/11/15 19:14, Boris Ostrovsky wrote: > After commit 8c058b0b9c34 ("x86/irq: Probe for PIC presence before > allocating descs for legacy IRQs") early_irq_init() will no longer > preallocate descriptors for legacy interrupts if PIC does not > exist, which is the case for Xen PV guests. > > Therefore we may need to allocate those descriptors ourselves. > > Signed-off-by: Boris Ostrovsky > Suggested-by: Thomas Gleixner Tested-by: Juergen Gross Juergen > --- > > v2: Use nr_legacy_irqs() instead of NR_IRQS_LEGACY (needs definition for ARM) > > arch/arm/include/asm/irq.h | 4 ++++ > drivers/xen/events/events_base.c | 5 +++-- > 2 files changed, 7 insertions(+), 2 deletions(-) > > diff --git a/arch/arm/include/asm/irq.h b/arch/arm/include/asm/irq.h > index be1d07d..b864f60 100644 > --- a/arch/arm/include/asm/irq.h > +++ b/arch/arm/include/asm/irq.h > @@ -2,6 +2,10 @@ > #define __ASM_ARM_IRQ_H > > #define NR_IRQS_LEGACY 16 > +static inline int nr_legacy_irqs(void) > +{ > + return NR_IRQS_LEGACY; > +} > > #ifndef CONFIG_SPARSE_IRQ > #include > diff --git a/drivers/xen/events/events_base.c b/drivers/xen/events/events_base.c > index 849500e..524c221 100644 > --- a/drivers/xen/events/events_base.c > +++ b/drivers/xen/events/events_base.c > @@ -39,6 +39,7 @@ > #include > #include > #include > +#include > #include > #endif > #include > @@ -420,7 +421,7 @@ static int __must_check xen_allocate_irq_gsi(unsigned gsi) > return xen_allocate_irq_dynamic(); > > /* Legacy IRQ descriptors are already allocated by the arch. */ > - if (gsi < NR_IRQS_LEGACY) > + if (gsi < nr_legacy_irqs()) > irq = gsi; > else > irq = irq_alloc_desc_at(gsi, -1); > @@ -446,7 +447,7 @@ static void xen_free_irq(unsigned irq) > kfree(info); > > /* Legacy IRQ descriptors are managed by the arch. */ > - if (irq < NR_IRQS_LEGACY) > + if (irq < nr_legacy_irqs()) > return; > > irq_free_desc(irq); > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/