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=-17.9 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 C8985C4363A for ; Fri, 30 Oct 2020 03:43:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 687C920EDD for ; Fri, 30 Oct 2020 03:43:05 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=synopsys.com header.i=@synopsys.com header.b="BHCZ7qEx" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726412AbgJ3DnE (ORCPT ); Thu, 29 Oct 2020 23:43:04 -0400 Received: from smtprelay-out1.synopsys.com ([149.117.87.133]:34378 "EHLO smtprelay-out1.synopsys.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726397AbgJ3DnB (ORCPT ); Thu, 29 Oct 2020 23:43:01 -0400 Received: from mailhost.synopsys.com (sv1-mailhost2.synopsys.com [10.205.2.132]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) (No client certificate requested) by smtprelay-out1.synopsys.com (Postfix) with ESMTPS id 6C7FFC00BE; Fri, 30 Oct 2020 03:42:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=synopsys.com; s=mail; t=1604029380; bh=kjSG/8bFRPHkB2CFhnWfjh3ZEfK5o+yA97DGB8dFr8Q=; h=From:To:Cc:Subject:Date:From; b=BHCZ7qExbozK0aztY3F+sO2bo5sMXt3MQCMvIei+aHMEQmme6f7GoSn5F6N16QbGa RNLb4mppRiQ47BkQy46JjM/ycrcLEYjAKERrG7ceL1u8pLcORqsiaqA1tHVqV4x2DR yycR2UpJGAcQiQJsvbmtiDy2if7YTifraxJ9emc5QkcoAnQuC9WByhzZjMl4czCIEe Xc/fIKrAM79L5Z17Up4+2japJZOJuPXu+EPvlDmx3Njlj9JrVj0m1Qh7aRm9Ne6nHy ImAZEcP1QTpb7nagOp2YdYB9guHmyCn+GM5GdLRTDXlh5aHEsXU0BWg217aInhbh91 icafQBl+WmbRA== Received: from vineetg-Latitude-7400.internal.synopsys.com (unknown [10.13.183.89]) by mailhost.synopsys.com (Postfix) with ESMTP id 21938A0072; Fri, 30 Oct 2020 03:42:56 +0000 (UTC) X-SNPS-Relay: synopsys.com From: Vineet Gupta To: linux-snps-arc@lists.infradead.org Cc: linux-kernel@vger.kernel.org, Vineet Gupta , David Hildenbrand , linux-mm@kvack.org Subject: [PATCH] ARC: [plat-hsdk] Remap CCMs super early in asm boot trampoline Date: Thu, 29 Oct 2020 20:42:54 -0700 Message-Id: <20201030034254.4166696-1-vgupta@synopsys.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org ARC HSDK platform stopped booting on released v5.10-rc1, getting stuck in startup of non master SMP cores. This was bisected to upstream commit 7fef431be9c9ac25 "(mm/page_alloc: place pages to tail in __free_pages_core())" That commit itself is harmless, it just exposed a subtle assumption in our platform code (hence CC'ing linux-mm just as FYI in case some other arches / platforms trip on it). The upstream commit is semantically disruptive as it reverses the order of page allocations (actually it can be good test for hardware verification to exercise different memory patterns altogether). For ARC HSDK platform that meant a remapped memory region (pertaining to unused Closely Coupled Memory) started getting used early for dynamice allocations, while not effectively remapped on all the cores, triggering memory error exception on those cores. The fix is to move the CCM remapping from early platform code to to early core boot code. And while it is undesirable to riddle common boot code with platform quirks, there is no other way to do this since the faltering code involves setting up stack itself so even function calls are not allowed at that point. If anyone is interested, all the gory details can be found at Link below. Link: https://github.com/foss-for-synopsys-dwc-arc-processors/linux/issues/32 Cc: David Hildenbrand Cc: linux-mm@kvack.org Signed-off-by: Vineet Gupta --- arch/arc/kernel/head.S | 17 ++++++++++++++++- arch/arc/plat-hsdk/platform.c | 17 ----------------- 2 files changed, 16 insertions(+), 18 deletions(-) diff --git a/arch/arc/kernel/head.S b/arch/arc/kernel/head.S index 17fd1ed700cc..9152782444b5 100644 --- a/arch/arc/kernel/head.S +++ b/arch/arc/kernel/head.S @@ -67,7 +67,22 @@ sr r5, [ARC_REG_LPB_CTRL] 1: #endif /* CONFIG_ARC_LPB_DISABLE */ -#endif + + /* On HSDK, CCMs need to remapped super early */ +#ifdef CONFIG_ARC_SOC_HSDK + mov r6, 0x60000000 + lr r5, [ARC_REG_ICCM_BUILD] + breq r5, 0, 1f + sr r6, [ARC_REG_AUX_ICCM] +1: + lr r5, [ARC_REG_DCCM_BUILD] + breq r5, 0, 2f + sr r6, [ARC_REG_AUX_DCCM] +2: +#endif /* CONFIG_ARC_SOC_HSDK */ + +#endif /* CONFIG_ISA_ARCV2 */ + ; Config DSP_CTRL properly, so kernel may use integer multiply, ; multiply-accumulate, and divide operations DSP_EARLY_INIT diff --git a/arch/arc/plat-hsdk/platform.c b/arch/arc/plat-hsdk/platform.c index 0b63fc095b99..b3ea1fa11f87 100644 --- a/arch/arc/plat-hsdk/platform.c +++ b/arch/arc/plat-hsdk/platform.c @@ -17,22 +17,6 @@ int arc_hsdk_axi_dmac_coherent __section(".data") = 0; #define ARC_CCM_UNUSED_ADDR 0x60000000 -static void __init hsdk_init_per_cpu(unsigned int cpu) -{ - /* - * By default ICCM is mapped to 0x7z while this area is used for - * kernel virtual mappings, so move it to currently unused area. - */ - if (cpuinfo_arc700[cpu].iccm.sz) - write_aux_reg(ARC_REG_AUX_ICCM, ARC_CCM_UNUSED_ADDR); - - /* - * By default DCCM is mapped to 0x8z while this area is used by kernel, - * so move it to currently unused area. - */ - if (cpuinfo_arc700[cpu].dccm.sz) - write_aux_reg(ARC_REG_AUX_DCCM, ARC_CCM_UNUSED_ADDR); -} #define ARC_PERIPHERAL_BASE 0xf0000000 #define CREG_BASE (ARC_PERIPHERAL_BASE + 0x1000) @@ -339,5 +323,4 @@ static const char *hsdk_compat[] __initconst = { MACHINE_START(SIMULATION, "hsdk") .dt_compat = hsdk_compat, .init_early = hsdk_init_early, - .init_per_cpu = hsdk_init_per_cpu, MACHINE_END -- 2.25.1