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 X-Spam-Level: X-Spam-Status: No, score=-11.5 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 73890C43387 for ; Tue, 8 Jan 2019 14:52:03 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 427B5206BB for ; Tue, 8 Jan 2019 14:52:03 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="fX9PHGu5" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 427B5206BB Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender:Content-Type: Content-Transfer-Encoding:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:Date:Message-ID:From: References:To:Subject:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=T5Q0neldaPredrwDziadoh2+jy3SEcVWGMcx72aTRGM=; b=fX9PHGu590+mArJnz5pzEbn1c TeyNZvJvNzto1X4IsXYbbBn7f0CGh48yXfhG+4NYZp3TBBRzmIXBOo9f2OBLptonAGZi5QEVgOsdb ii+7Vgc8EkvAfLQeWk+LJ34qMRu+v99X6DZdBO/FmoEpzyNG/PguPH6rv/Ioy/iOQGr7UAO3MPt4w Cgwx10Twz1Rt9bIiOnn9UyrZtPkBgv/Vi5xUOsm9NSQUyN7MbhfgOaoCXfkrMATiKyza5QJ/c+29N 4bIjgIPjridaUpX5hpbH6KS2oS6Hjn0A4rFv1+b4rxzKb39TGXf6l/9MYntX5lC+37nMUjKhgB/wy 1nHkSqHCA==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1ggsjX-0005r8-3x; Tue, 08 Jan 2019 14:51:59 +0000 Received: from foss.arm.com ([217.140.101.70]) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1ggsjS-0005qH-JU for linux-arm-kernel@lists.infradead.org; Tue, 08 Jan 2019 14:51:56 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 863C680D; Tue, 8 Jan 2019 06:51:52 -0800 (PST) Received: from [10.1.196.93] (en101.cambridge.arm.com [10.1.196.93]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id B50543F5AF; Tue, 8 Jan 2019 06:51:50 -0800 (PST) Subject: Re: [PATCH v8 15/26] arm64: alternative: Apply alternatives early in boot process To: Julien Thierry , linux-arm-kernel@lists.infradead.org References: <1546956464-48825-1-git-send-email-julien.thierry@arm.com> <1546956464-48825-16-git-send-email-julien.thierry@arm.com> From: Suzuki K Poulose Message-ID: Date: Tue, 8 Jan 2019 14:51:48 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.2.1 MIME-Version: 1.0 In-Reply-To: <1546956464-48825-16-git-send-email-julien.thierry@arm.com> Content-Language: en-US X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190108_065154_655391_BA6F2D04 X-CRM114-Status: GOOD ( 26.73 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: mark.rutland@arm.com, daniel.thompson@linaro.org, marc.zyngier@arm.com, catalin.marinas@arm.com, will.deacon@arm.com, linux-kernel@vger.kernel.org, christoffer.dall@arm.com, james.morse@arm.com, joel@joelfernandes.org Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hi Julien, On 08/01/2019 14:07, Julien Thierry wrote: > From: Daniel Thompson > > Currently alternatives are applied very late in the boot process (and > a long time after we enable scheduling). Some alternative sequences, > such as those that alter the way CPU context is stored, must be applied > much earlier in the boot sequence. > > Introduce apply_boot_alternatives() to allow some alternatives to be > applied immediately after we detect the CPU features of the boot CPU. > > Signed-off-by: Daniel Thompson > [julien.thierry@arm.com: rename to fit new cpufeature framework better, > apply BOOT_SCOPE feature early in boot] > Signed-off-by: Julien Thierry > Cc: Catalin Marinas > Cc: Will Deacon > Cc: Christoffer Dall > Cc: Suzuki K Poulose > --- > arch/arm64/include/asm/alternative.h | 1 + > arch/arm64/include/asm/cpufeature.h | 4 ++++ > arch/arm64/kernel/alternative.c | 43 +++++++++++++++++++++++++++++++----- > arch/arm64/kernel/cpufeature.c | 6 +++++ > arch/arm64/kernel/smp.c | 7 ++++++ > 5 files changed, 56 insertions(+), 5 deletions(-) > > diff --git a/arch/arm64/include/asm/alternative.h b/arch/arm64/include/asm/alternative.h > index 9806a23..b9f8d78 100644 > --- a/arch/arm64/include/asm/alternative.h > +++ b/arch/arm64/include/asm/alternative.h > @@ -25,6 +25,7 @@ struct alt_instr { > typedef void (*alternative_cb_t)(struct alt_instr *alt, > __le32 *origptr, __le32 *updptr, int nr_inst); > > +void __init apply_boot_alternatives(void); > void __init apply_alternatives_all(void); > bool alternative_is_applied(u16 cpufeature); > > diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h > index 89c3f31..e505e1f 100644 > --- a/arch/arm64/include/asm/cpufeature.h > +++ b/arch/arm64/include/asm/cpufeature.h > @@ -391,6 +391,10 @@ static inline int cpucap_default_scope(const struct arm64_cpu_capabilities *cap) > extern struct static_key_false cpu_hwcap_keys[ARM64_NCAPS]; > extern struct static_key_false arm64_const_caps_ready; > > +/* ARM64 CAPS + alternative_cb */ > +#define ARM64_NPATCHABLE (ARM64_NCAPS + 1) > +extern DECLARE_BITMAP(boot_capabilities, ARM64_NPATCHABLE); > + > #define for_each_available_cap(cap) \ > for_each_set_bit(cap, cpu_hwcaps, ARM64_NCAPS) > > diff --git a/arch/arm64/kernel/alternative.c b/arch/arm64/kernel/alternative.c > index c947d22..a9b4677 100644 > --- a/arch/arm64/kernel/alternative.c > +++ b/arch/arm64/kernel/alternative.c > @@ -155,7 +155,8 @@ static void clean_dcache_range_nopatch(u64 start, u64 end) > } while (cur += d_size, cur < end); > } > > -static void __apply_alternatives(void *alt_region, bool is_module) > +static void __apply_alternatives(void *alt_region, bool is_module, > + unsigned long *feature_mask) > { > struct alt_instr *alt; > struct alt_region *region = alt_region; > @@ -165,6 +166,9 @@ static void __apply_alternatives(void *alt_region, bool is_module) > for (alt = region->begin; alt < region->end; alt++) { > int nr_inst; > > + if (!test_bit(alt->cpufeature, feature_mask)) > + continue; > + > /* Use ARM64_CB_PATCH as an unconditional patch */ > if (alt->cpufeature < ARM64_CB_PATCH && > !cpus_have_cap(alt->cpufeature)) > @@ -203,8 +207,11 @@ static void __apply_alternatives(void *alt_region, bool is_module) > __flush_icache_all(); > isb(); > > - /* We applied all that was available */ > - bitmap_copy(applied_alternatives, cpu_hwcaps, ARM64_NCAPS); > + /* Ignore ARM64_CB bit from feature mask */ > + bitmap_or(applied_alternatives, applied_alternatives, > + feature_mask, ARM64_NCAPS); > + bitmap_and(applied_alternatives, applied_alternatives, > + cpu_hwcaps, ARM64_NCAPS); > } > } > > @@ -225,8 +232,13 @@ static int __apply_alternatives_multi_stop(void *unused) > cpu_relax(); > isb(); > } else { > + DECLARE_BITMAP(remaining_capabilities, ARM64_NPATCHABLE); > + > + bitmap_complement(remaining_capabilities, boot_capabilities, > + ARM64_NPATCHABLE); > + > BUG_ON(all_alternatives_applied); > - __apply_alternatives(®ion, false); > + __apply_alternatives(®ion, false, remaining_capabilities); > /* Barriers provided by the cache flushing */ > WRITE_ONCE(all_alternatives_applied, 1); > } > @@ -240,6 +252,24 @@ void __init apply_alternatives_all(void) > stop_machine(__apply_alternatives_multi_stop, NULL, cpu_online_mask); > } > > +/* > + * This is called very early in the boot process (directly after we run > + * a feature detect on the boot CPU). No need to worry about other CPUs > + * here. > + */ > +void __init apply_boot_alternatives(void) > +{ > + struct alt_region region = { > + .begin = (struct alt_instr *)__alt_instructions, > + .end = (struct alt_instr *)__alt_instructions_end, > + }; > + > + /* If called on non-boot cpu things could go wrong */ > + WARN_ON(smp_processor_id() != 0); > + > + __apply_alternatives(®ion, false, &boot_capabilities[0]); > +} > + > #ifdef CONFIG_MODULES > void apply_alternatives_module(void *start, size_t length) > { > @@ -247,7 +277,10 @@ void apply_alternatives_module(void *start, size_t length) > .begin = start, > .end = start + length, > }; > + DECLARE_BITMAP(all_capabilities, ARM64_NPATCHABLE); > + > + bitmap_fill(all_capabilities, ARM64_NPATCHABLE); > > - __apply_alternatives(®ion, true); > + __apply_alternatives(®ion, true, &all_capabilities[0]); > } > #endif > diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c > index 84fa5be..71c8d4f 100644 > --- a/arch/arm64/kernel/cpufeature.c > +++ b/arch/arm64/kernel/cpufeature.c > @@ -54,6 +54,9 @@ > EXPORT_SYMBOL(cpu_hwcaps); > static struct arm64_cpu_capabilities const __ro_after_init *cpu_hwcaps_ptrs[ARM64_NCAPS]; > > +/* Need also bit for ARM64_CB_PATCH */ > +DECLARE_BITMAP(boot_capabilities, ARM64_NPATCHABLE); > + > /* > * Flag to indicate if we have computed the system wide > * capabilities based on the boot time active CPUs. This > @@ -1672,6 +1675,9 @@ static void update_cpu_capabilities(u16 scope_mask) > if (caps->desc) > pr_info("detected: %s\n", caps->desc); > cpus_set_cap(caps->capability); > + > + if (caps->type & SCOPE_BOOT_CPU) You may want to do : if (scope_mask & SCOPE_BOOT_CPU) for a tighter check to ensure this doesn't update the boot_capabilities after we have applied the boot_scope alternatives and miss applying the alternatives for those, should someone add a multi-scope (i.e SCOPE_BOOT_CPU and something else) capability (even by mistake). With that: Reviewed-by: Suzuki K Poulose _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel