From mboxrd@z Thu Jan 1 00:00:00 1970 From: Boris Ostrovsky Subject: Re: [PATCH] xen/events: Always allocate legacy interrupts on PV guests Date: Tue, 24 Nov 2015 09:36:28 -0500 Message-ID: <565475EC.40804__25442.8429798738$1448376429$gmane$org@oracle.com> References: <1448036704-18630-1-git-send-email-boris.ostrovsky@oracle.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Stefano Stabellini , linux@arm.linux.org.uk, will.deacon@arm.com, catalin.marinas@arm.com Cc: jgross@suse.com, linux-kernel@vger.kernel.org, xen-devel@lists.xen.org, stefano.stabellini@citrix.com, david.vrabel@citrix.com, vkuznets@redhat.com, tglx@linutronix.de, linux-arm-kernel@lists.infradead.org List-Id: xen-devel@lists.xenproject.org On 11/20/2015 11:35 AM, Stefano Stabellini wrote: > On Fri, 20 Nov 2015, 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 > Acked-by: Stefano Stabellini I realized that I neglected to add ARM64 maintainers here. Adding them now. (And this also need an ACK/NACK from Russell) -boris > > >> v3: Add arm64 definition of nr_legacy_irqs() >> >> arch/arm/include/asm/irq.h | 4 ++++ >> arch/arm64/include/asm/irq.h | 6 ++++++ >> drivers/xen/events/events_base.c | 5 +++-- >> 3 files changed, 13 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/arch/arm64/include/asm/irq.h b/arch/arm64/include/asm/irq.h >> index 23eb450..24ba8d8 100644 >> --- a/arch/arm64/include/asm/irq.h >> +++ b/arch/arm64/include/asm/irq.h >> @@ -7,4 +7,10 @@ struct pt_regs; >> >> extern void set_handle_irq(void (*handle_irq)(struct pt_regs *)); >> >> +#define NR_IRQS_LEGACY 0 >> +static inline int nr_legacy_irqs(void) >> +{ >> + return NR_IRQS_LEGACY; >> +} >> + >> #endif >> 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); >> -- >> 2.1.0 >>