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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E150AC433EF for ; Wed, 11 May 2022 19:31:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S245560AbiEKTbm (ORCPT ); Wed, 11 May 2022 15:31:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59112 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1343611AbiEKTbL (ORCPT ); Wed, 11 May 2022 15:31:11 -0400 Received: from gloria.sntech.de (gloria.sntech.de [185.11.138.130]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9A34960D6 for ; Wed, 11 May 2022 12:31:09 -0700 (PDT) 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 1nos1m-0004fe-Lr; Wed, 11 May 2022 21:29:42 +0200 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 11/12] riscv: don't use global static vars to store alternative data Date: Wed, 11 May 2022 21:29:20 +0200 Message-Id: <20220511192921.2223629-12-heiko@sntech.de> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220511192921.2223629-1-heiko@sntech.de> References: <20220511192921.2223629-1-heiko@sntech.de> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.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 Reviewed-by: Guo Ren Reviewed-by: Philipp Tomsich --- 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); -- 2.35.1