From patchwork Mon May 6 06:41:34 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Benjamin Herrenschmidt X-Patchwork-Id: 241558 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from ozlabs.org (localhost [IPv6:::1]) by ozlabs.org (Postfix) with ESMTP id 69B932C0224 for ; Mon, 6 May 2013 16:42:15 +1000 (EST) Received: from gate.crashing.org (gate.crashing.org [63.228.1.57]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 179B32C00DE for ; Mon, 6 May 2013 16:41:45 +1000 (EST) Received: from [127.0.0.1] (localhost.localdomain [127.0.0.1]) by gate.crashing.org (8.14.1/8.13.8) with ESMTP id r466fYlM017062; Mon, 6 May 2013 01:41:35 -0500 Message-ID: <1367822494.15842.12.camel@pasglop> Subject: [PATCH] irqdomain: Allow quiet failure mode From: Benjamin Herrenschmidt To: linuxppc-dev@lists.ozlabs.org Date: Mon, 06 May 2013 16:41:34 +1000 X-Mailer: Evolution 3.6.4-0ubuntu1 Mime-Version: 1.0 Cc: Grant Likely X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" Some interrupt controllers refuse to map interrupts marked as "protected" by firwmare. Since we try to map everyting in the device-tree on some platforms, we end up with a lot of nasty WARN's in the boot log for what is a normal situation on those machines. This defines a specific return code (-EPERM) from the host map() callback which cause irqdomain to fail silently. MPIC is updated to return this when hitting a protected source printing only a single line message for diagnostic purposes. Signed-off-by: Benjamin Herrenschmidt Grant, I'm happy to merge that myself provided I have your ack, it fixes an annoying problem on Cell introduced by previous changes to irqdomain (not recent but users started to notice). arch/powerpc/sysdev/mpic.c | 14 +++++++++++--- kernel/irq/irqdomain.c | 20 +++++++++++++++++--- 2 files changed, 28 insertions(+), 6 deletions(-) Acked-by: Grant Likely diff --git a/arch/powerpc/sysdev/mpic.c b/arch/powerpc/sysdev/mpic.c index d30e6a6..ee21b5e 100644 --- a/arch/powerpc/sysdev/mpic.c +++ b/arch/powerpc/sysdev/mpic.c @@ -1001,8 +1001,12 @@ static int mpic_host_map(struct irq_domain *h, unsigned int virq, if (hw == mpic->spurious_vec) return -EINVAL; - if (mpic->protected && test_bit(hw, mpic->protected)) - return -EINVAL; + if (mpic->protected && test_bit(hw, mpic->protected)) { + pr_warning("mpic: Mapping of source 0x%x failed, " + "source protected by firmware !\n",\ + (unsigned int)hw); + return -EPERM; + } #ifdef CONFIG_SMP else if (hw >= mpic->ipi_vecs[0]) { @@ -1029,8 +1033,12 @@ static int mpic_host_map(struct irq_domain *h, unsigned int virq, if (mpic_map_error_int(mpic, virq, hw)) return 0; - if (hw >= mpic->num_sources) + if (hw >= mpic->num_sources) { + pr_warning("mpic: Mapping of source 0x%x failed, " + "source out of range !\n",\ + (unsigned int)hw); return -EINVAL; + } mpic_msi_reserve_hwirq(mpic, hw); diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c index 96f3a1d..5a83dde 100644 --- a/kernel/irq/irqdomain.c +++ b/kernel/irq/irqdomain.c @@ -462,9 +462,23 @@ int irq_domain_associate_many(struct irq_domain *domain, unsigned int irq_base, if (domain->ops->map) { ret = domain->ops->map(domain, virq, hwirq); if (ret != 0) { - pr_err("irq-%i==>hwirq-0x%lx mapping failed: %d\n", - virq, hwirq, ret); - WARN_ON(1); + /* + * If map() returns -EPERM, this interrupt is protected + * by the firmware or some other service and shall not + * be mapped. + * + * Since on some platforms we blindly try to map everything + * we end up with a log full of backtraces. + * + * So instead, we silently fail on -EPERM, it is the + * responsibility of the PIC driver to display a relevant + * message if needed. + */ + if (ret != -EPERM) { + pr_err("irq-%i==>hwirq-0x%lx mapping failed: %d\n", + virq, hwirq, ret); + WARN_ON(1); + } irq_data->domain = NULL; irq_data->hwirq = 0; goto err_unmap;