From patchwork Wed Apr 6 16:45:18 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: James Morse X-Patchwork-Id: 558565 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 27755C433F5 for ; Wed, 6 Apr 2022 18:06:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240113AbiDFSIX (ORCPT ); Wed, 6 Apr 2022 14:08:23 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56632 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240441AbiDFSHy (ORCPT ); Wed, 6 Apr 2022 14:07:54 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id DE5E618CD0C; Wed, 6 Apr 2022 09:46:15 -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 C501512FC; Wed, 6 Apr 2022 09:46:15 -0700 (PDT) Received: from eglon.cambridge.arm.com (eglon.cambridge.arm.com [10.1.196.218]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 2334C3F73B; Wed, 6 Apr 2022 09:46:15 -0700 (PDT) From: James Morse To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: James Morse , Catalin Marinas Subject: [stable:PATCH v4.9.309 15/43] arm64: arch_timer: Add erratum handler for CPU-specific capability Date: Wed, 6 Apr 2022 17:45:18 +0100 Message-Id: <20220406164546.1888528-15-james.morse@arm.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220406164546.1888528-1-james.morse@arm.com> References: <0220406164217.1888053-1-james.morse@arm.com> <20220406164546.1888528-1-james.morse@arm.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Marc Zyngier commit 0064030c6fd4ca6cfab42de037b2a89445beeead upstream. Should we ever have a workaround for an erratum that is detected using a capability and affecting a particular CPU, it'd be nice to have a way to probe them directly. Acked-by: Thomas Gleixner Signed-off-by: Marc Zyngier Signed-off-by: James Morse --- arch/arm64/include/asm/arch_timer.h | 1 + drivers/clocksource/arm_arch_timer.c | 28 ++++++++++++++++++++++++---- 2 files changed, 25 insertions(+), 4 deletions(-) diff --git a/arch/arm64/include/asm/arch_timer.h b/arch/arm64/include/asm/arch_timer.h index 5cd964e90d11..1b0d7e994e0c 100644 --- a/arch/arm64/include/asm/arch_timer.h +++ b/arch/arm64/include/asm/arch_timer.h @@ -39,6 +39,7 @@ extern struct static_key_false arch_timer_read_ool_enabled; enum arch_timer_erratum_match_type { ate_match_dt, + ate_match_local_cap_id, }; struct arch_timer_erratum_workaround { diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c index 015b28e7f1f2..138dbfdfb413 100644 --- a/drivers/clocksource/arm_arch_timer.c +++ b/drivers/clocksource/arm_arch_timer.c @@ -162,6 +162,13 @@ bool arch_timer_check_dt_erratum(const struct arch_timer_erratum_workaround *wa, return of_property_read_bool(np, wa->id); } +static +bool arch_timer_check_local_cap_erratum(const struct arch_timer_erratum_workaround *wa, + const void *arg) +{ + return this_cpu_has_cap((uintptr_t)wa->id); +} + static const struct arch_timer_erratum_workaround * arch_timer_iterate_errata(enum arch_timer_erratum_match_type type, ate_match_fn_t match_fn, @@ -192,14 +199,16 @@ static void arch_timer_check_ool_workaround(enum arch_timer_erratum_match_type t { const struct arch_timer_erratum_workaround *wa; ate_match_fn_t match_fn = NULL; - - if (static_branch_unlikely(&arch_timer_read_ool_enabled)) - return; + bool local = false; switch (type) { case ate_match_dt: match_fn = arch_timer_check_dt_erratum; break; + case ate_match_local_cap_id: + match_fn = arch_timer_check_local_cap_erratum; + local = true; + break; default: WARN_ON(1); return; @@ -209,8 +218,17 @@ static void arch_timer_check_ool_workaround(enum arch_timer_erratum_match_type t if (!wa) return; + if (needs_unstable_timer_counter_workaround()) { + if (wa != timer_unstable_counter_workaround) + pr_warn("Can't enable workaround for %s (clashes with %s\n)", + wa->desc, + timer_unstable_counter_workaround->desc); + return; + } + arch_timer_enable_workaround(wa); - pr_info("Enabling global workaround for %s\n", wa->desc); + pr_info("Enabling %s workaround for %s\n", + local ? "local" : "global", wa->desc); } #else @@ -470,6 +488,8 @@ static void __arch_timer_setup(unsigned type, BUG(); } + arch_timer_check_ool_workaround(ate_match_local_cap_id, NULL); + erratum_workaround_set_sne(clk); } else { clk->features |= CLOCK_EVT_FEAT_DYNIRQ;