From patchwork Mon Aug 12 17:30:12 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Julien Grall X-Patchwork-Id: 171114 Delivered-To: patch@linaro.org Received: by 2002:a92:d204:0:0:0:0:0 with SMTP id y4csp3121911ily; Mon, 12 Aug 2019 10:33:25 -0700 (PDT) X-Google-Smtp-Source: APXvYqzXsT80VVYcYmqsQ1QXljj6c/T8Sby/RBeH0S+iussN5FxC1oKFC865lVG+cfa+DwudKjcS X-Received: by 2002:a02:7f15:: with SMTP id r21mr34641616jac.120.1565631109354; Mon, 12 Aug 2019 10:31:49 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1565631109; cv=none; d=google.com; s=arc-20160816; b=vG0+hyr6G/cbV84W5dspV9GQ2XaHJLjq3BcZFtGp00LnVwRAYS4758R6ku80foCysl 4RYsc0uH3fTLXyRoOMBNqiXEXc7ZMr6OLI4LF2FHUKpkycfyVG7pT8OXbIdIFYBDbz/v P+/pJSk+tuwYrcT7PZNqLh59NHIN7Jtf0s4xMCpFBD8ytoSXxC5NvJiTXQzUX3guar9c NNziMqzP4YAnxti3dEzDO+dWulH10A9UA3KQU5JxODmMTKIJ+vvb/ToA8g/0iNZgIcP5 JAAYm/McE9MLcn1yE2SVj0H9HTeyN32zHrMj7wKUykaKjTbpwpyQBPAwqhhItQfSGlrn zrww== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=sender:errors-to:content-transfer-encoding:mime-version:cc :list-subscribe:list-help:list-post:list-unsubscribe:list-id :precedence:subject:references:in-reply-to:message-id:date:to:from; bh=YQnWtnj+k7l4DQOhSeQaVkrfCTZPJHAFo5iFqugBerk=; b=PyYYONjXV5bVw8FXemMAJWgb2RApBWoAYX3+MJC33mLQFOUIg4dO0mzFUYVPmWByeD qXFSkjQqykPGXTNcFbg5AypjHpewsC1ndS6Y767rw15LqEO1L71GNrI1aw+rjLcY6Hue 5R9XryeFMVn9eN5mIePb788Pwck2A+Ep6ZHE7/Z5jr8yhtl+1aODaLIMo1KXHQwb/oHC YnfvmD/m4RGWQgS6kd/i/GV+63efwNgSYDwMqwlzv4Do7dUBtrCCNh6koTwNMqwVLK+y Jv4ubp37lVPoDIPmbxBA06sGHh7YRtZ2K/vvZQjY7mxRWTz5KuKNikmKJmYxotlkJhQ7 /D1A== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of xen-devel-bounces@lists.xenproject.org designates 192.237.175.120 as permitted sender) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Return-Path: Received: from lists.xenproject.org (lists.xenproject.org. [192.237.175.120]) by mx.google.com with ESMTPS id l27si1431149jac.34.2019.08.12.10.31.49 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Mon, 12 Aug 2019 10:31:49 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of xen-devel-bounces@lists.xenproject.org designates 192.237.175.120 as permitted sender) client-ip=192.237.175.120; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of xen-devel-bounces@lists.xenproject.org designates 192.237.175.120 as permitted sender) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1hxE9g-0006v6-RG; Mon, 12 Aug 2019 17:30:48 +0000 Received: from us1-rack-dfw2.inumbo.com ([104.130.134.6]) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1hxE9f-0006tT-Jc for xen-devel@lists.xenproject.org; Mon, 12 Aug 2019 17:30:47 +0000 X-Inumbo-ID: eb29bb4c-bd26-11e9-8980-bc764e045a96 Received: from foss.arm.com (unknown [217.140.110.172]) by us1-rack-dfw2.inumbo.com (Halon) with ESMTP id eb29bb4c-bd26-11e9-8980-bc764e045a96; Mon, 12 Aug 2019 17:30:46 +0000 (UTC) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 3C15915AB; Mon, 12 Aug 2019 10:30:46 -0700 (PDT) Received: from e108454-lin.cambridge.arm.com (e108454-lin.cambridge.arm.com [10.1.196.50]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 8A9343F706; Mon, 12 Aug 2019 10:30:45 -0700 (PDT) From: Julien Grall To: xen-devel@lists.xenproject.org Date: Mon, 12 Aug 2019 18:30:12 +0100 Message-Id: <20190812173019.11956-22-julien.grall@arm.com> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20190812173019.11956-1-julien.grall@arm.com> References: <20190812173019.11956-1-julien.grall@arm.com> Subject: [Xen-devel] [PATCH v3 21/28] xen/arm32: head: Rework and document setup_fixmap() X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Cc: Julien Grall , Stefano Stabellini , Volodymyr Babchuk MIME-Version: 1.0 Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" At the moment, the fixmap table is only hooked when earlyprintk is used. This is fine today because in C land, the fixmap is not used by anyone until the the boot CPU is switching to the runtime page-tables. In the future, the boot CPU will not switch between page-tables to avoid TLB incoherency. Thus, the fixmap table will need to be always hooked beofre any use. Let's start doing it now in setup_fixmap(). Lastly, document the behavior and the main registers usage within the function. Signed-off-by: Julien Grall Reviewed-by: Stefano Stabellini --- Changes in v3: - The unused label is now removed in the previous patch - Add Stefano's reviewed-by Changes in v2: - Patch added --- xen/arch/arm/arm32/head.S | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-) diff --git a/xen/arch/arm/arm32/head.S b/xen/arch/arm/arm32/head.S index 34fc9ffcee..ee5c3d2af8 100644 --- a/xen/arch/arm/arm32/head.S +++ b/xen/arch/arm/arm32/head.S @@ -541,8 +541,21 @@ identity_mapping_removed: mov pc, lr ENDPROC(remove_identity_mapping) +/* + * Map the UART in the fixmap (when earlyprintk is used) and hook the + * fixmap table in the page tables. + * + * The fixmap cannot be mapped in create_page_tables because it may + * clash with the 1:1 mapping. + * + * Inputs: + * r10: Physical offset + * r11: Early UART base physical address + * + * Clobbers r1 - r4 + */ setup_fixmap: -#if defined(CONFIG_EARLY_PRINTK) /* Fixmap is only used by early printk */ +#if defined(CONFIG_EARLY_PRINTK) /* Add UART to the fixmap table */ ldr r1, =xen_fixmap /* r1 := vaddr (xen_fixmap) */ lsr r2, r11, #THIRD_SHIFT @@ -551,6 +564,7 @@ setup_fixmap: orr r2, r2, #PT_LOWER(DEV_L3) /* r2:r3 := 4K dev map including UART */ mov r3, #0x0 strd r2, r3, [r1, #(FIXMAP_CONSOLE*8)] /* Map it in the first fixmap's slot */ +#endif /* Map fixmap into boot_second */ ldr r1, =boot_second /* r1 := vaddr (boot_second) */ @@ -565,7 +579,7 @@ setup_fixmap: /* Ensure any page table updates made above have occurred. */ dsb nshst -#endif + mov pc, lr ENDPROC(setup_fixmap)