From patchwork Thu Mar 24 00:07:09 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Heiko Stuebner X-Patchwork-Id: 12790278 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 72939C433F5 for ; Thu, 24 Mar 2022 00:10:48 +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:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=39NSpaNlWIcPGB4rfbpBheVperc1FRfRqx9tdep7FPI=; b=eMFpmmPKjPTR3Q JcyWGJeDY1ap9+oly/RzV2Kh2zBcLr5H52/ZRhEZjW1+oGV1yD5PcmfCNKNnUTrSMn1NhE2S1mG1K Z6HMO4bQQVIlNRapaSLFe38e7nydV91lNwPGOGXfTniuYOtvmxgXy6+PQP1MUDcgsBLiJhg43+C6R 3WzzUpWr2/jTuUbBhZp+NlGqUk7N6cMrUsFbs5kwDSocM5it1cI/P5RuMbbhxVzsNca2IOikw3BhO XO/HIWjCzUIw2nealSgv+g3wsgky02vogfit07j4qtp/Kw32lxbc2HJ0H5K9CeL+5wd84IYnF0TCq TMf512E+97DtAm/TAukQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nXB3o-00FB7x-D5; Thu, 24 Mar 2022 00:10:40 +0000 Received: from gloria.sntech.de ([185.11.138.130]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1nXB3l-00FB6t-NI for linux-riscv@lists.infradead.org; Thu, 24 Mar 2022 00:10:39 +0000 Received: from ip5b412258.dynamic.kabel-deutschland.de ([91.65.34.88] helo=phil.lan) by gloria.sntech.de with esmtpsa (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1nXB0u-00055s-8y; Thu, 24 Mar 2022 01:07:40 +0100 From: Heiko Stuebner To: palmer@dabbelt.com, paul.walmsley@sifive.com, aou@eecs.berkeley.edu Cc: linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, wefu@redhat.com, liush@allwinnertech.com, guoren@kernel.org, atishp@atishpatra.org, anup@brainfault.org, drew@beagleboard.org, hch@lst.de, arnd@arndb.de, wens@csie.org, maxime@cerno.tech, gfavor@ventanamicro.com, andrea.mondelli@huawei.com, behrensj@mit.edu, xinhaoqu@huawei.com, mick@ics.forth.gr, allen.baum@esperantotech.com, jscheid@ventanamicro.com, rtrauben@gmail.com, samuel@sholland.org, cmuellner@linux.com, philipp.tomsich@vrull.eu, Heiko Stuebner Subject: [PATCH v8 13/14] riscv: don't use global static vars to store alternative data Date: Thu, 24 Mar 2022 01:07:09 +0100 Message-Id: <20220324000710.575331-14-heiko@sntech.de> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220324000710.575331-1-heiko@sntech.de> References: <20220324000710.575331-1-heiko@sntech.de> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220323_171037_783858_58139A7A X-CRM114-Status: GOOD ( 14.96 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org Right now the code uses a global struct to store vendor-ids and another global variable to store the vendor-patch-function. There exist specific cases where we'll need to patch the kernel at an even earlier stage, where trying to write to a static variable might actually result in hangs. Also collecting the vendor-information consists of 3 sbi-ecalls (or csr-reads) which is pretty negligible in the context of booting a kernel. So rework the code to not rely on static variables and instead collect the vendor-information when a round of alternatives is to be applied. Signed-off-by: Heiko Stuebner --- arch/riscv/kernel/alternative.c | 51 ++++++++++++++++----------------- 1 file changed, 24 insertions(+), 27 deletions(-) diff --git a/arch/riscv/kernel/alternative.c b/arch/riscv/kernel/alternative.c index e6c9de9f9ba6..27f722ae452b 100644 --- a/arch/riscv/kernel/alternative.c +++ b/arch/riscv/kernel/alternative.c @@ -16,41 +16,35 @@ #include #include -static struct cpu_manufacturer_info_t { +struct cpu_manufacturer_info_t { unsigned long vendor_id; unsigned long arch_id; unsigned long imp_id; -} cpu_mfr_info; + void (*vendor_patch_func)(struct alt_entry *begin, struct alt_entry *end, + unsigned long archid, unsigned long impid, + unsigned int stage); +}; -static void (*vendor_patch_func)(struct alt_entry *begin, struct alt_entry *end, - unsigned long archid, unsigned long impid, - unsigned int stage) __initdata_or_module; - -static inline void __init riscv_fill_cpu_mfr_info(void) +static void __init_or_module riscv_fill_cpu_mfr_info(struct cpu_manufacturer_info_t *cpu_mfr_info) { #ifdef CONFIG_RISCV_M_MODE - cpu_mfr_info.vendor_id = csr_read(CSR_MVENDORID); - cpu_mfr_info.arch_id = csr_read(CSR_MARCHID); - cpu_mfr_info.imp_id = csr_read(CSR_MIMPID); + cpu_mfr_info->vendor_id = csr_read(CSR_MVENDORID); + cpu_mfr_info->arch_id = csr_read(CSR_MARCHID); + cpu_mfr_info->imp_id = csr_read(CSR_MIMPID); #else - cpu_mfr_info.vendor_id = sbi_get_mvendorid(); - cpu_mfr_info.arch_id = sbi_get_marchid(); - cpu_mfr_info.imp_id = sbi_get_mimpid(); + cpu_mfr_info->vendor_id = sbi_get_mvendorid(); + cpu_mfr_info->arch_id = sbi_get_marchid(); + cpu_mfr_info->imp_id = sbi_get_mimpid(); #endif -} - -static void __init init_alternative(void) -{ - riscv_fill_cpu_mfr_info(); - switch (cpu_mfr_info.vendor_id) { + switch (cpu_mfr_info->vendor_id) { #ifdef CONFIG_ERRATA_SIFIVE case SIFIVE_VENDOR_ID: - vendor_patch_func = sifive_errata_patch_func; + cpu_mfr_info->vendor_patch_func = sifive_errata_patch_func; break; #endif default: - vendor_patch_func = NULL; + cpu_mfr_info->vendor_patch_func = NULL; } } @@ -63,14 +57,19 @@ static void __init_or_module _apply_alternatives(struct alt_entry *begin, struct alt_entry *end, unsigned int stage) { + struct cpu_manufacturer_info_t cpu_mfr_info; + + riscv_fill_cpu_mfr_info(&cpu_mfr_info); + riscv_cpufeature_patch_func(begin, end, stage); - if (!vendor_patch_func) + if (!cpu_mfr_info.vendor_patch_func) return; - vendor_patch_func(begin, end, - cpu_mfr_info.arch_id, cpu_mfr_info.imp_id, - stage); + cpu_mfr_info.vendor_patch_func(begin, end, + cpu_mfr_info.arch_id, + cpu_mfr_info.imp_id, + stage); } void __init apply_boot_alternatives(void) @@ -78,8 +77,6 @@ void __init apply_boot_alternatives(void) /* If called on non-boot cpu things could go wrong */ WARN_ON(smp_processor_id() != 0); - init_alternative(); - _apply_alternatives((struct alt_entry *)__alt_start, (struct alt_entry *)__alt_end, RISCV_ALTERNATIVES_BOOT);