From patchwork Tue Jan 8 14:07:33 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Julien Thierry X-Patchwork-Id: 154973 Delivered-To: patch@linaro.org Received: by 2002:a02:48:0:0:0:0:0 with SMTP id 69csp4921980jaa; Tue, 8 Jan 2019 06:08:36 -0800 (PST) X-Google-Smtp-Source: ALg8bN7F7vh+5AXD4Ddd+Um4yXZHR4/lCfzFczIHUUaBjpJt0s9dIiYMpguz4a0UHXOHKqdiGb9x X-Received: by 2002:a17:902:7896:: with SMTP id q22mr1943943pll.280.1546956516874; Tue, 08 Jan 2019 06:08:36 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1546956516; cv=none; d=google.com; s=arc-20160816; b=qGsS9IfiSd1l1borIpTHdYBo3vikixHBNq+O7T8npW1lJI86Zl7KFY2cnRKj+A6Lk/ 9UfX+aeYlz+3OOT3YTn9gYvnzpvfBAuP7nYeySksyIarzepDVQx9snm3K5+wEHWklcmG h/GA3IKUEkBZsH0KLkMQLle2Ty/gR0uS0otR1T/0Gd1hOWttF9r9j9kfHcDiAuRZrOpS BksZDrqHigWFNsIVVLRf8AR9K2oRKDQOhrOovBicX1uZ+kcS/r11Utr0dqqlpu+I1SE8 h5uFT9ojc/l5taiOjz33UwvH9GXJ/zHOy8TJulgk45+8ohIsnSGk60RJ2j/ELEKLwxEG HztA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:references:in-reply-to:message-id:date :subject:cc:to:from; bh=2oaBCS0axhqaq6VcRV0AH7nFF4Dqjg4T7pJzxX16sdM=; b=PW8Fl4FgkBeL90uuWMWm/vd8QxB07oF8ctAdfJJb1CZACVbI7aGQjgh9NUtLpfmKjS lQovwEjlYkSMtCXzICI92hdWA5ldlwXi8qefgrr+YjyL7HaLWWG25+2gMPK/NB8YwTva Ei71vYfYT8vKquQUcvdrxGCo/U48XSrhwlWq8bjku5IYQ2LvNQMC3WhQSmxNpS7Dk1hW HsRZFnNpywkS3JIzgz4WOi/C1r5zF8iwlz1+OB5mTyMR7cuMQOCnqh5hQS3tBL37D9ul CE0wAc1RLUN6Kac8radoLkxxisnbG2ViN4bJbBAvXfGgp0pP5oL+uRBc9foa8VOQVCy4 g0Xg== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id 68si6189699pgh.320.2019.01.08.06.08.36; Tue, 08 Jan 2019 06:08:36 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729080AbfAHOIe (ORCPT + 31 others); Tue, 8 Jan 2019 09:08:34 -0500 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:52322 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729009AbfAHOId (ORCPT ); Tue, 8 Jan 2019 09:08:33 -0500 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 BA93F1B55; Tue, 8 Jan 2019 06:08:32 -0800 (PST) Received: from e112298-lin.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.72.51.249]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id C78CA3F70D; Tue, 8 Jan 2019 06:08:30 -0800 (PST) From: Julien Thierry To: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org, daniel.thompson@linaro.org, joel@joelfernandes.org, marc.zyngier@arm.com, christoffer.dall@arm.com, james.morse@arm.com, catalin.marinas@arm.com, will.deacon@arm.com, mark.rutland@arm.com, Julien Thierry , Suzuki K Poulose Subject: [PATCH v8 15/26] arm64: alternative: Apply alternatives early in boot process Date: Tue, 8 Jan 2019 14:07:33 +0000 Message-Id: <1546956464-48825-16-git-send-email-julien.thierry@arm.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1546956464-48825-1-git-send-email-julien.thierry@arm.com> References: <1546956464-48825-1-git-send-email-julien.thierry@arm.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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(-) -- 1.9.1 Reviewed-by: Suzuki K Poulose 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) + set_bit(caps->capability, boot_capabilities); } } diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c index 1598d6f..a944edd 100644 --- a/arch/arm64/kernel/smp.c +++ b/arch/arm64/kernel/smp.c @@ -419,6 +419,13 @@ void __init smp_prepare_boot_cpu(void) */ jump_label_init(); cpuinfo_store_boot_cpu(); + + /* + * We now know enough about the boot CPU to apply the + * alternatives that cannot wait until interrupt handling + * and/or scheduling is enabled. + */ + apply_boot_alternatives(); } static u64 __init of_get_cpu_mpidr(struct device_node *dn)