From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id AAA3CEEAA4E for ; Thu, 14 Sep 2023 15:03:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-ID:Subject:CC:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=2/thg5HKj1DCjBMNUkMbnPP/6UIV+wDTXF9Na8zJ8Y8=; b=dO5lfx5y5SOGmd Co734N+kAnbe2zfJWfWukL1GTaw65FDCvLjmog4Uq4i4zHoPrQHLLR0881WyTppmVW4+coHlYo3He FpkNuJjFHa4zhYKhpUADgXQrE1Foi13EDRHMNjjFHpzHEf++ZtBPsf7Z4uBgfym+RHV8KDqjOQn23 5JZ2hmz1Rr/KMXaIX8DbKUvUZrhAfNj7VXX4nu5JJbeleMOnJ+EUxe2FHmaw4tjsPBo0MBpgFsN/E MVExs1rxqhq6Ox67zJw5La/7s9W0vLscGa4HXG+IUGnRqSrQQb0VU/qKsvuGD07Fk2xW7r4CnIJug JUAH7ck8U9dwBdgttDhw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qgnrY-008jKw-1m; Thu, 14 Sep 2023 15:02:36 +0000 Received: from frasgout.his.huawei.com ([185.176.79.56]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1qgnrW-008jIR-0i; Thu, 14 Sep 2023 15:02:35 +0000 Received: from lhrpeml500005.china.huawei.com (unknown [172.18.147.200]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4RmgWw1VMVz6K5sT; Thu, 14 Sep 2023 23:01:48 +0800 (CST) Received: from localhost (10.202.227.76) by lhrpeml500005.china.huawei.com (7.191.163.240) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.31; Thu, 14 Sep 2023 16:02:24 +0100 Date: Thu, 14 Sep 2023 16:02:23 +0100 From: Jonathan Cameron To: James Morse CC: , , , , , , , , , Salil Mehta , Russell King , Jean-Philippe Brucker , , Subject: Re: [RFC PATCH v2 29/35] irqchip/gic-v3: Don't return errors from gic_acpi_match_gicc() Message-ID: <20230914160223.0000782f@Huawei.com> In-Reply-To: <20230913163823.7880-30-james.morse@arm.com> References: <20230913163823.7880-1-james.morse@arm.com> <20230913163823.7880-30-james.morse@arm.com> Organization: Huawei Technologies Research and Development (UK) Ltd. X-Mailer: Claws Mail 4.1.0 (GTK 3.24.33; x86_64-w64-mingw32) MIME-Version: 1.0 X-Originating-IP: [10.202.227.76] X-ClientProxiedBy: lhrpeml500006.china.huawei.com (7.191.161.198) To lhrpeml500005.china.huawei.com (7.191.163.240) X-CFilter-Loop: Reflected X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230914_080234_541526_B7D0B68E X-CRM114-Status: GOOD ( 23.83 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Wed, 13 Sep 2023 16:38:17 +0000 James Morse wrote: > gic_acpi_match_gicc() is only called via gic_acpi_count_gicr_regions(). > It should only count the number of enabled redistributors, but it > also tries to sanity check the GICC entry, currently returning an > error if the Enabled bit is set, but the gicr_base_address is zero. > > Adding support for the online-capable bit to the sanity check > complicates it, for no benefit. The existing check implicitly > depends on gic_acpi_count_gicr_regions() previous failing to find > any GICR regions (as it is valid to have gicr_base_address of zero if > the redistributors are described via a GICR entry). > > Instead of complicating the check, remove it. Failures that happen > at this point cause the irqchip not to register, meaning no irqs > can be requested. The kernel grinds to a panic() pretty quickly. > > Without the check, MADT tables that exhibit this problem are still > caught by gic_populate_rdist(), which helpfully also prints what > went wrong: > | CPU4: mpidr 100 has no re-distributor! > > Signed-off-by: James Morse > --- > drivers/irqchip/irq-gic-v3.c | 18 ++++++------------ > 1 file changed, 6 insertions(+), 12 deletions(-) > > diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c > index 72d3cdebdad1..0f54811262eb 100644 > --- a/drivers/irqchip/irq-gic-v3.c > +++ b/drivers/irqchip/irq-gic-v3.c > @@ -2415,21 +2415,15 @@ static int __init gic_acpi_match_gicc(union acpi_subtable_headers *header, > > /* > * If GICC is enabled and has valid gicr base address, then it means > - * GICR base is presented via GICC > + * GICR base is presented via GICC. The redistributor is only known to > + * be accessible if the GICC is marked as enabled. If this bit is not > + * set, we'd need to add the redistributor at runtime, which isn't > + * supported. > */ > - if (acpi_gicc_is_usable(gicc) && gicc->gicr_base_address) { > + if (gicc->flags & ACPI_MADT_ENABLED && gicc->gicr_base_address) Going in circles... > acpi_data.enabled_rdists++; > - return 0; > - } > > - /* > - * It's perfectly valid firmware can pass disabled GICC entry, driver > - * should not treat as errors, skip the entry instead of probe fail. > - */ > - if (!acpi_gicc_is_usable(gicc)) > - return 0; > - > - return -ENODEV; > + return 0; > } > > static int __init gic_acpi_count_gicr_regions(void) _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel