From patchwork Wed Sep 13 16:38:17 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: James Morse X-Patchwork-Id: 722412 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 49635EE01E0 for ; Wed, 13 Sep 2023 16:41:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231272AbjIMQlv (ORCPT ); Wed, 13 Sep 2023 12:41:51 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58456 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231273AbjIMQlE (ORCPT ); Wed, 13 Sep 2023 12:41:04 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 6477A2733; Wed, 13 Sep 2023 09:39:51 -0700 (PDT) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 505AE139F; Wed, 13 Sep 2023 09:40:28 -0700 (PDT) Received: from merodach.members.linode.com (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 55C453F5A1; Wed, 13 Sep 2023 09:39:49 -0700 (PDT) From: James Morse To: linux-pm@vger.kernel.org, loongarch@lists.linux.dev, linux-acpi@vger.kernel.org, linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-riscv@lists.infradead.org, kvmarm@lists.linux.dev Cc: x86@kernel.org, Salil Mehta , Russell King , Jean-Philippe Brucker , jianyong.wu@arm.com, justin.he@arm.com Subject: [RFC PATCH v2 29/35] irqchip/gic-v3: Don't return errors from gic_acpi_match_gicc() Date: Wed, 13 Sep 2023 16:38:17 +0000 Message-Id: <20230913163823.7880-30-james.morse@arm.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20230913163823.7880-1-james.morse@arm.com> References: <20230913163823.7880-1-james.morse@arm.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org 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 Reviewed-by: Gavin Shan --- 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) 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)