From patchwork Sat Jul 25 17:34:24 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Julien Grall X-Patchwork-Id: 6865251 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 96A47C05AC for ; Sat, 25 Jul 2015 17:40:52 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 83F9620660 for ; Sat, 25 Jul 2015 17:40:51 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 5733C20629 for ; Sat, 25 Jul 2015 17:40:50 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1ZJ3OC-0001lC-N8; Sat, 25 Jul 2015 17:37:36 +0000 Received: from smtp.citrix.com ([66.165.176.89]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1ZJ3MZ-00014M-Ag for linux-arm-kernel@lists.infradead.org; Sat, 25 Jul 2015 17:36:08 +0000 X-IronPort-AV: E=Sophos;i="5.15,542,1432598400"; d="scan'208";a="284387255" From: Julien Grall To: Subject: [PATCH] xen/events: Support event channel rebind on ARM Date: Sat, 25 Jul 2015 18:34:24 +0100 Message-ID: <1437845664-32098-1-git-send-email-julien.grall@citrix.com> X-Mailer: git-send-email 2.1.4 MIME-Version: 1.0 X-DLP: MIA1 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20150725_103556_354852_CCE0E836 X-CRM114-Status: GOOD ( 14.26 ) X-Spam-Score: -8.1 (--------) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: x86@kernel.org, ian.campbell@citrix.com, stefano.stabellini@eu.citrix.com, Catalin Marinas , Konrad Rzeszutek Wilk , Will Deacon , linux-kernel@vger.kernel.org, Julien Grall , Ingo Molnar , David Vrabel , "H. Peter Anvin" , Boris Ostrovsky , Thomas Gleixner , linux-arm-kernel@lists.infradead.org Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-5.4 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Currently, the event channel rebind code is gated with the presence of the vector callback. The virtual interrupt controller on ARM has the concept of per-CPU interrupt (PPI) which allow us to support per-VCPU event channel. Therefore there is no need of vector callback for ARM. Xen is already using a free PPI to notify the guest VCPU of an event. Furthermore, the xen code initialization in Linux (see arch/arm/xen/enlighten.c) is requesting correctly a per-CPU IRQ. Introduce new macro xen_support_evtchn_rebind to allow architecture decide whether rebind an event is support or not. It will always return 1 on ARM and keep the same behavior on x86. This is also allow us to drop the usage of xen_have_vector_callback entirely in the ARM code. Signed-off-by: Julien Grall Cc: Stefano Stabellini Cc: Catalin Marinas Cc: Will Deacon Cc: Konrad Rzeszutek Wilk Cc: Boris Ostrovsky Cc: David Vrabel Cc: Thomas Gleixner Cc: Ingo Molnar Cc: "H. Peter Anvin" Cc: x86@kernel.org Reviewed-by: David Vrabel --- Tested by setting the affinity manually via /proc on dom0 ARM64 --- arch/arm/include/asm/xen/events.h | 3 +++ arch/arm/xen/enlighten.c | 4 ---- arch/arm64/include/asm/xen/events.h | 3 +++ arch/x86/include/asm/xen/events.h | 9 +++++++++ drivers/xen/events/events_base.c | 6 +----- include/xen/events.h | 1 - 6 files changed, 16 insertions(+), 10 deletions(-) diff --git a/arch/arm/include/asm/xen/events.h b/arch/arm/include/asm/xen/events.h index 8b1f37b..72d467f 100644 --- a/arch/arm/include/asm/xen/events.h +++ b/arch/arm/include/asm/xen/events.h @@ -20,4 +20,7 @@ static inline int xen_irqs_disabled(struct pt_regs *regs) atomic64_t, \ counter), (val)) +/* Rebind event channel is supported by default */ +#define xen_support_evtchn_rebind() (1) + #endif /* _ASM_ARM_XEN_EVENTS_H */ diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c index 9055c92..c50c8d3 100644 --- a/arch/arm/xen/enlighten.c +++ b/arch/arm/xen/enlighten.c @@ -45,10 +45,6 @@ static struct vcpu_info __percpu *xen_vcpu_info; unsigned long xen_released_pages; struct xen_memory_region xen_extra_mem[XEN_EXTRA_MEM_MAX_REGIONS] __initdata; -/* TODO: to be removed */ -__read_mostly int xen_have_vector_callback; -EXPORT_SYMBOL_GPL(xen_have_vector_callback); - static __read_mostly unsigned int xen_events_irq; static __initdata struct device_node *xen_node; diff --git a/arch/arm64/include/asm/xen/events.h b/arch/arm64/include/asm/xen/events.h index 8655321..259eef0 100644 --- a/arch/arm64/include/asm/xen/events.h +++ b/arch/arm64/include/asm/xen/events.h @@ -18,4 +18,7 @@ static inline int xen_irqs_disabled(struct pt_regs *regs) #define xchg_xen_ulong(ptr, val) xchg((ptr), (val)) +/* Rebind event channel is supported by default */ +#define xen_support_evtchn_rebind() (1) + #endif /* _ASM_ARM64_XEN_EVENTS_H */ diff --git a/arch/x86/include/asm/xen/events.h b/arch/x86/include/asm/xen/events.h index 608a79d..e8ed478 100644 --- a/arch/x86/include/asm/xen/events.h +++ b/arch/x86/include/asm/xen/events.h @@ -20,4 +20,13 @@ static inline int xen_irqs_disabled(struct pt_regs *regs) /* No need for a barrier -- XCHG is a barrier on x86. */ #define xchg_xen_ulong(ptr, val) xchg((ptr), (val)) +/* + * Events delivered via platform PCI interrupts are always + * routed to vcpu 0 and hence cannot be rebound. + */ +#define xen_support_evtchn_rebind() \ + (!xen_hvm_domain() || xen_have_vector_callback) + +extern int xen_have_vector_callback; + #endif /* _ASM_X86_XEN_EVENTS_H */ diff --git a/drivers/xen/events/events_base.c b/drivers/xen/events/events_base.c index 96093ae..ed620e5 100644 --- a/drivers/xen/events/events_base.c +++ b/drivers/xen/events/events_base.c @@ -1301,11 +1301,7 @@ static int rebind_irq_to_cpu(unsigned irq, unsigned tcpu) if (!VALID_EVTCHN(evtchn)) return -1; - /* - * Events delivered via platform PCI interrupts are always - * routed to vcpu 0 and hence cannot be rebound. - */ - if (xen_hvm_domain() && !xen_have_vector_callback) + if (!xen_support_evtchn_rebind()) return -1; /* Send future instances of this interrupt to other vcpu. */ diff --git a/include/xen/events.h b/include/xen/events.h index 7d95fdf..88da2ab 100644 --- a/include/xen/events.h +++ b/include/xen/events.h @@ -92,7 +92,6 @@ void xen_hvm_callback_vector(void); #ifdef CONFIG_TRACING #define trace_xen_hvm_callback_vector xen_hvm_callback_vector #endif -extern int xen_have_vector_callback; int xen_set_callback_via(uint64_t via); void xen_evtchn_do_upcall(struct pt_regs *regs); void xen_hvm_evtchn_do_upcall(void);