Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760596AbbKTPSX (ORCPT ); Fri, 20 Nov 2015 10:18:23 -0500 Received: from aserp1040.oracle.com ([141.146.126.69]:22057 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760581AbbKTPSU (ORCPT ); Fri, 20 Nov 2015 10:18:20 -0500 Subject: Re: [PATCH v2] xen/events: Always allocate legacy interrupts on PV guests To: Stefano Stabellini References: <1447870445-17199-1-git-send-email-boris.ostrovsky@oracle.com> Cc: konrad.wilk@oracle.com, david.vrabel@citrix.com, linux@arm.linux.org.uk, stefano.stabellini@citrix.com, jgross@suse.com, tglx@linutronix.de, vkuznets@redhat.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, xen-devel@lists.xen.org, Catalin Marinas , Will Deacon From: Boris Ostrovsky Message-ID: <564F397A.8010203@oracle.com> Date: Fri, 20 Nov 2015 10:17:14 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.1.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit X-Source-IP: userv0021.oracle.com [156.151.31.71] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3916 Lines: 111 On 11/20/2015 06:24 AM, Stefano Stabellini wrote: > On Wed, 18 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 > You need to do this for arm64 too. > > FYI you can download arm64 cross-compilers from > https://releases.linaro.org/14.04/components/toolchain/binaries/ > then you can use them by exporting ARCH=arm64 and > CROSS_COMPILE=/path/to/gcc-linaro-aarch64-linux-gnu-version/bin/aarch64-linux-gnu- I did test on arm but didn't realize that arm64 uses different include files. Does arm64 not have any legacy interrupts? BTW, I got this build error: STUBCPY drivers/firmware/efi/libstub/lib-sort.stub.o 0000000000000000 R_AARCH64_ABS64 __efistub_sort 0000000000000008 R_AARCH64_ABS64 .init__ksymtab_strings drivers/firmware/efi/libstub/lib-sort.stub.o: absolute symbol references not allowed in the EFI stub drivers/firmware/efi/libstub/Makefile:63: recipe for target 'drivers/firmware/efi/libstub/lib-sort.stub.o' failed make[4]: *** [drivers/firmware/efi/libstub/lib-sort.stub.o] Error 1 scripts/Makefile.build:403: recipe for target 'drivers/firmware/efi/libstub' failed make[3]: *** [drivers/firmware/efi/libstub] Error 2 scripts/Makefile.build:403: recipe for target 'drivers/firmware/efi' failed make[2]: *** [drivers/firmware/efi] Error 2 scripts/Makefile.build:403: recipe for target 'drivers/firmware' failed make[1]: *** [drivers/firmware] Error 2 Makefile:943: recipe for target 'drivers' failed make: *** [drivers] Error 2 I worked around this by removing some of EFI config options but presumably this needs to be properly fixed. -boris > > >> 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); >> -- >> 2.1.0 >> -- 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/