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=-16.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,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 1BA8CC433E2 for ; Mon, 22 Mar 2021 18:44:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E38DE6199E for ; Mon, 22 Mar 2021 18:43:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231327AbhCVSnk (ORCPT ); Mon, 22 Mar 2021 14:43:40 -0400 Received: from so254-9.mailgun.net ([198.61.254.9]:29725 "EHLO so254-9.mailgun.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232030AbhCVSnW (ORCPT ); Mon, 22 Mar 2021 14:43:22 -0400 DKIM-Signature: a=rsa-sha256; v=1; c=relaxed/relaxed; d=mg.codeaurora.org; q=dns/txt; s=smtp; t=1616438602; h=Message-Id: Date: Subject: Cc: To: From: Sender; bh=UAE86TM7cBWMTScfwM9qAFxkopoKgSbUvffSe5UtCqU=; b=TUmk/kfZHMrEr6QCPau4Aosx2eGdkhzykliZgiWGPSJg2CnTfzFXLK/R/gEbsZ/EnotsB9Xa XZqvixcu3NREEp81WS4QGOr0c91UZdtpj/fFwfbnMoyzS86hvqKOqSxdDeuyeAa+anXw8SUG o1F2Vd3sDO8kaOuRotA4WN4RAPY= X-Mailgun-Sending-Ip: 198.61.254.9 X-Mailgun-Sid: WyI0MWYwYSIsICJsaW51eC1rZXJuZWxAdmdlci5rZXJuZWwub3JnIiwgImJlOWU0YSJd Received: from smtp.codeaurora.org (ec2-35-166-182-171.us-west-2.compute.amazonaws.com [35.166.182.171]) by smtp-out-n06.prod.us-west-2.postgun.com with SMTP id 6058e53fe2200c0a0dc3c4f1 (version=TLS1.2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256); Mon, 22 Mar 2021 18:43:11 GMT Sender: mojha=codeaurora.org@mg.codeaurora.org Received: by smtp.codeaurora.org (Postfix, from userid 1001) id 07E47C433ED; Mon, 22 Mar 2021 18:43:11 +0000 (UTC) Received: from mojha-linux.qualcomm.com (unknown [202.46.22.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: mojha) by smtp.codeaurora.org (Postfix) with ESMTPSA id D3F55C433C6; Mon, 22 Mar 2021 18:43:07 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org D3F55C433C6 Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: aws-us-west-2-caf-mail-1.web.codeaurora.org; spf=fail smtp.mailfrom=mojha@codeaurora.org From: Mukesh Ojha To: linux-kernel@vger.kernel.org Cc: keescook@chromium.org, anton@enomsg.org, ccross@android.com, tony.luck@intel.com, Mukesh Ojha Subject: [PATCH v3] pstore: Add mem_type property DT parsing support Date: Tue, 23 Mar 2021 00:12:17 +0530 Message-Id: <1616438537-13719-1-git-send-email-mojha@codeaurora.org> X-Mailer: git-send-email 2.7.4 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org There could be a scenario where we define some region in normal memory and use them store to logs which is later retrieved by bootloader during warm reset. In this scenario, we wanted to treat this memory as normal cacheable memory instead of default behaviour which is an overhead. Making it cacheable could improve performance. This commit gives control to change mem_type from Device tree, and also documents the value for normal memory. Signed-off-by: Mukesh Ojha --- Changes in v3: - Minor code and documentation update done as per comment given by Kees. Changes in v2: - if-else converted to switch case - updated MODULE_PARM_DESC with new memory type. - default setting is still intact. Documentation/admin-guide/ramoops.rst | 4 +++- .../devicetree/bindings/reserved-memory/ramoops.txt | 10 ++++++++-- fs/pstore/ram.c | 7 ++++++- fs/pstore/ram_core.c | 18 ++++++++++++++++-- 4 files changed, 33 insertions(+), 6 deletions(-) diff --git a/Documentation/admin-guide/ramoops.rst b/Documentation/admin-guide/ramoops.rst index b0a1ae7..8f107d8 100644 --- a/Documentation/admin-guide/ramoops.rst +++ b/Documentation/admin-guide/ramoops.rst @@ -3,7 +3,7 @@ Ramoops oops/panic logger Sergiu Iordache -Updated: 17 November 2011 +Updated: 10 Feb 2021 Introduction ------------ @@ -30,6 +30,8 @@ mapping to pgprot_writecombine. Setting ``mem_type=1`` attempts to use depends on atomic operations. At least on ARM, pgprot_noncached causes the memory to be mapped strongly ordered, and atomic operations on strongly ordered memory are implementation defined, and won't work on many ARMs such as omaps. +Setting ``mem_type=2`` attempts to treat the memory region as normal memory, +which enables full cache on it. This can improve the performance. The memory area is divided into ``record_size`` chunks (also rounded down to power of two) and each kmesg dump writes a ``record_size`` chunk of diff --git a/Documentation/devicetree/bindings/reserved-memory/ramoops.txt b/Documentation/devicetree/bindings/reserved-memory/ramoops.txt index b7886fe..6f1cb20 100644 --- a/Documentation/devicetree/bindings/reserved-memory/ramoops.txt +++ b/Documentation/devicetree/bindings/reserved-memory/ramoops.txt @@ -42,8 +42,14 @@ Optional properties: - pmsg-size: size in bytes of log buffer reserved for userspace messages (defaults to 0: disabled) -- unbuffered: if present, use unbuffered mappings to map the reserved region - (defaults to buffered mappings) +- mem-type: if present, sets the type of mapping is to be used to map the + reserved region. mem-type: 0 = write-combined (default), 1 = unbuffered, + 2 = cached. + +- unbuffered: deprecated, use mem_type instead. if present, and mem_type is + not specified, it is equivalent to mem_type = 1 and uses unbuffered mappings + to map the reserved region (defaults to buffered mappings mem_type = 0). If + both are specified -- "mem_type" overrides "unbuffered". - max-reason: if present, sets maximum type of kmsg dump reasons to store (defaults to 2: log Oopses and Panics). This can be set to INT_MAX to diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c index ca6d8a8..fefe3d3 100644 --- a/fs/pstore/ram.c +++ b/fs/pstore/ram.c @@ -56,7 +56,7 @@ MODULE_PARM_DESC(mem_size, static unsigned int mem_type; module_param(mem_type, uint, 0400); MODULE_PARM_DESC(mem_type, - "set to 1 to try to use unbuffered memory (default 0)"); + "memory type: 0=write-combined (default), 1=unbuffered, 2=cached"); static int ramoops_max_reason = -1; module_param_named(max_reason, ramoops_max_reason, int, 0400); @@ -648,6 +648,10 @@ static int ramoops_parse_dt(struct platform_device *pdev, pdata->mem_size = resource_size(res); pdata->mem_address = res->start; + /* + * Setting "unbuffered" is deprecated and will be ignored if + * "mem_type" is also specified. + */ pdata->mem_type = of_property_read_bool(of_node, "unbuffered"); /* * Setting "no-dump-oops" is deprecated and will be ignored if @@ -666,6 +670,7 @@ static int ramoops_parse_dt(struct platform_device *pdev, field = value; \ } + parse_u32("mem-type", pdata->record_size, pdata->mem_type); parse_u32("record-size", pdata->record_size, 0); parse_u32("console-size", pdata->console_size, 0); parse_u32("ftrace-size", pdata->ftrace_size, 0); diff --git a/fs/pstore/ram_core.c b/fs/pstore/ram_core.c index fff363b..fe53050 100644 --- a/fs/pstore/ram_core.c +++ b/fs/pstore/ram_core.c @@ -396,6 +396,10 @@ void persistent_ram_zap(struct persistent_ram_zone *prz) persistent_ram_update_header_ecc(prz); } +#define MEM_TYPE_WCOMBINE 0 +#define MEM_TYPE_NONCACHED 1 +#define MEM_TYPE_NORMAL 2 + static void *persistent_ram_vmap(phys_addr_t start, size_t size, unsigned int memtype) { @@ -409,10 +413,20 @@ static void *persistent_ram_vmap(phys_addr_t start, size_t size, page_start = start - offset_in_page(start); page_count = DIV_ROUND_UP(size + offset_in_page(start), PAGE_SIZE); - if (memtype) + switch (memtype) { + case MEM_TYPE_NORMAL: + prot = PAGE_KERNEL; + break; + case MEM_TYPE_NONCACHED: prot = pgprot_noncached(PAGE_KERNEL); - else + break; + case MEM_TYPE_WCOMBINE: prot = pgprot_writecombine(PAGE_KERNEL); + break; + default: + pr_err("invalid mem_type=%d\n", memtype); + return NULL; + } pages = kmalloc_array(page_count, sizeof(struct page *), GFP_KERNEL); if (!pages) { -- Qualcomm India Private Limited, on behalf of Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project