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=-7.3 required=3.0 tests=BAYES_00,DKIM_ADSP_CUSTOM_MED, DKIM_INVALID,DKIM_SIGNED,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no 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 B6A1DC433DB for ; Thu, 14 Jan 2021 19:26:12 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 366D023B3E for ; Thu, 14 Jan 2021 19:26:11 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 366D023B3E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from bilbo.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 4DGvS15ZW2zDrpn for ; Fri, 15 Jan 2021 06:26:09 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=gmail.com (client-ip=2607:f8b0:4864:20::629; helo=mail-pl1-x629.google.com; envelope-from=f.fainelli@gmail.com; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20161025 header.b=sJaFTBZ3; dkim-atps=neutral Received: from mail-pl1-x629.google.com (mail-pl1-x629.google.com [IPv6:2607:f8b0:4864:20::629]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4DGvMB5ZNCzDscm for ; Fri, 15 Jan 2021 06:21:57 +1100 (AEDT) Received: by mail-pl1-x629.google.com with SMTP id j1so3425476pld.3 for ; Thu, 14 Jan 2021 11:21:56 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:autocrypt:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=tF8uyKERWCoMyAnlRKqJDO1qWaCVQS8YdldPCqsx9S0=; b=sJaFTBZ37WgPKnSYnIC9X0ttgJ4KnYrNxbfK23tXhe3FVi2plUEkuCgczIjgNj1soe zOgfMT0+s/KHUkB+I8lHtDfOggJsnE+TBYwLFhae8QCqBUKHfhXAvx6taH8R3eQrNryU hCeov6owT+z0GIUsPKd2AQykVhGzkhAt7EfpX9InyZPXfN8HL1URiEfPWV3Vk08PnIMr vJ89xFZQq+npyP4fyXbsm4M9Q0OfURLHAXeBS6jYm9atoBh443ZHdzRCKQ+Wysf+i4ZI zfPeZwqnzRaeFDAUlmAIk8KrE5opaScYFnCLgvucoARS2zz9WsfsCWydTb7yNvShWYlM LIwQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:autocrypt :message-id:date:user-agent:mime-version:in-reply-to :content-language:content-transfer-encoding; bh=tF8uyKERWCoMyAnlRKqJDO1qWaCVQS8YdldPCqsx9S0=; b=XnjcKOq6ga6D0A7FC7L+Ug1/mobyjRI7QHq0GqaQIvulRMakMx+CtdXjy1xIohhwae 3kJ0XbgY98SL55VrXzt/MICc3brIqDLPv6+q3rJgNMTsWx1ftKJpymAm1kZlO5wzOWRq Na+7uY4OUTsSmEthlwHdjAB/aJoAXZXJHnsy4V7FMF8v2hnch5zU0LbaVU159aix3SUL DG4NYdy9/F+bhE/Zl28nYK54zPYNjdWduxSgChIPucqI2M6dYTe64TybNFtAUxO+ATaL wOA2lKPkaJWtXxd4vL+V3ev9+vxRA8xQUbD70JyRVtZ9K7G1s8JpeEw2hnMYZ8lcovmF 7aWw== X-Gm-Message-State: AOAM532Cfi94kWTP0BwVWfQ8H9PDOnhw9UYLHjib6Nw7z4NTj0AZWpX/ WR9zL4Qc1l/3taZixF8bCXPGLvk3xX8= X-Google-Smtp-Source: ABdhPJyPo9ML0x66bHS+KgpIhpg94ojy5fT6fH9mQxG7FMKBoEYl0Sy3IFq3hGAQTn1h+1yxXOP42w== X-Received: by 2002:aa7:81d6:0:b029:19e:2987:7465 with SMTP id c22-20020aa781d60000b029019e29877465mr8761737pfn.29.1610650373721; Thu, 14 Jan 2021 10:52:53 -0800 (PST) Received: from [10.67.48.230] ([192.19.223.252]) by smtp.googlemail.com with ESMTPSA id r11sm43351596pjj.2.2021.01.14.10.52.50 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 14 Jan 2021 10:52:52 -0800 (PST) Subject: Re: [RFC PATCH v3 6/6] of: Add plumbing for restricted DMA pool To: Claire Chang References: <20210106034124.30560-1-tientzu@chromium.org> <20210106034124.30560-7-tientzu@chromium.org> <95e6dd76-5e18-e445-c351-19fba18f36de@gmail.com> From: Florian Fainelli Autocrypt: addr=f.fainelli@gmail.com; prefer-encrypt=mutual; keydata= mQGiBEjPuBIRBACW9MxSJU9fvEOCTnRNqG/13rAGsj+vJqontvoDSNxRgmafP8d3nesnqPyR xGlkaOSDuu09rxuW+69Y2f1TzjFuGpBk4ysWOR85O2Nx8AJ6fYGCoeTbovrNlGT1M9obSFGQ X3IzRnWoqlfudjTO5TKoqkbOgpYqIo5n1QbEjCCwCwCg3DOH/4ug2AUUlcIT9/l3pGvoRJ0E AICDzi3l7pmC5IWn2n1mvP5247urtHFs/uusE827DDj3K8Upn2vYiOFMBhGsxAk6YKV6IP0d ZdWX6fqkJJlu9cSDvWtO1hXeHIfQIE/xcqvlRH783KrihLcsmnBqOiS6rJDO2x1eAgC8meAX SAgsrBhcgGl2Rl5gh/jkeA5ykwbxA/9u1eEuL70Qzt5APJmqVXR+kWvrqdBVPoUNy/tQ8mYc nzJJ63ng3tHhnwHXZOu8hL4nqwlYHRa9eeglXYhBqja4ZvIvCEqSmEukfivk+DlIgVoOAJbh qIWgvr3SIEuR6ayY3f5j0f2ejUMYlYYnKdiHXFlF9uXm1ELrb0YX4GMHz7QnRmxvcmlhbiBG YWluZWxsaSA8Zi5mYWluZWxsaUBnbWFpbC5jb20+iGYEExECACYCGyMGCwkIBwMCBBUCCAME FgIDAQIeAQIXgAUCVF/S8QUJHlwd3wAKCRBhV5kVtWN2DvCVAJ4u4/bPF4P3jxb4qEY8I2gS 6hG0gACffNWlqJ2T4wSSn+3o7CCZNd7SLSC5BA0ESM+4EhAQAL/o09boR9D3Vk1Tt7+gpYr3 WQ6hgYVON905q2ndEoA2J0dQxJNRw3snabHDDzQBAcqOvdi7YidfBVdKi0wxHhSuRBfuOppu pdXkb7zxuPQuSveCLqqZWRQ+Cc2QgF7SBqgznbe6Ngout5qXY5Dcagk9LqFNGhJQzUGHAsIs hap1f0B1PoUyUNeEInV98D8Xd/edM3mhO9nRpUXRK9Bvt4iEZUXGuVtZLT52nK6Wv2EZ1TiT OiqZlf1P+vxYLBx9eKmabPdm3yjalhY8yr1S1vL0gSA/C6W1o/TowdieF1rWN/MYHlkpyj9c Rpc281gAO0AP3V1G00YzBEdYyi0gaJbCEQnq8Vz1vDXFxHzyhgGz7umBsVKmYwZgA8DrrB0M oaP35wuGR3RJcaG30AnJpEDkBYHznI2apxdcuTPOHZyEilIRrBGzDwGtAhldzlBoBwE3Z3MY 31TOpACu1ZpNOMysZ6xiE35pWkwc0KYm4hJA5GFfmWSN6DniimW3pmdDIiw4Ifcx8b3mFrRO BbDIW13E51j9RjbO/nAaK9ndZ5LRO1B/8Fwat7bLzmsCiEXOJY7NNpIEpkoNoEUfCcZwmLrU +eOTPzaF6drw6ayewEi5yzPg3TAT6FV3oBsNg3xlwU0gPK3v6gYPX5w9+ovPZ1/qqNfOrbsE FRuiSVsZQ5s3AAMFD/9XjlnnVDh9GX/r/6hjmr4U9tEsM+VQXaVXqZuHKaSmojOLUCP/YVQo 7IiYaNssCS4FCPe4yrL4FJJfJAsbeyDykMN7wAnBcOkbZ9BPJPNCbqU6dowLOiy8AuTYQ48m vIyQ4Ijnb6GTrtxIUDQeOBNuQC/gyyx3nbL/lVlHbxr4tb6YkhkO6shjXhQh7nQb33FjGO4P WU11Nr9i/qoV8QCo12MQEo244RRA6VMud06y/E449rWZFSTwGqb0FS0seTcYNvxt8PB2izX+ HZA8SL54j479ubxhfuoTu5nXdtFYFj5Lj5x34LKPx7MpgAmj0H7SDhpFWF2FzcC1bjiW9mjW HaKaX23Awt97AqQZXegbfkJwX2Y53ufq8Np3e1542lh3/mpiGSilCsaTahEGrHK+lIusl6mz Joil+u3k01ofvJMK0ZdzGUZ/aPMZ16LofjFA+MNxWrZFrkYmiGdv+LG45zSlZyIvzSiG2lKy kuVag+IijCIom78P9jRtB1q1Q5lwZp2TLAJlz92DmFwBg1hyFzwDADjZ2nrDxKUiybXIgZp9 aU2d++ptEGCVJOfEW4qpWCCLPbOT7XBr+g/4H3qWbs3j/cDDq7LuVYIe+wchy/iXEJaQVeTC y5arMQorqTFWlEOgRA8OP47L9knl9i4xuR0euV6DChDrguup2aJVU4hPBBgRAgAPAhsMBQJU X9LxBQkeXB3fAAoJEGFXmRW1Y3YOj4UAn3nrFLPZekMeqX5aD/aq/dsbXSfyAKC45Go0YyxV HGuUuzv+GKZ6nsysJ7kCDQRXG8fwARAA6q/pqBi5PjHcOAUgk2/2LR5LjjesK50bCaD4JuNc YDhFR7Vs108diBtsho3w8WRd9viOqDrhLJTroVckkk74OY8r+3t1E0Dd4wHWHQZsAeUvOwDM PQMqTUBFuMi6ydzTZpFA2wBR9x6ofl8Ax+zaGBcFrRlQnhsuXLnM1uuvS39+pmzIjasZBP2H UPk5ifigXcpelKmj6iskP3c8QN6x6GjUSmYx+xUfs/GNVSU1XOZn61wgPDbgINJd/THGdqiO iJxCLuTMqlSsmh1+E1dSdfYkCb93R/0ZHvMKWlAx7MnaFgBfsG8FqNtZu3PCLfizyVYYjXbV WO1A23riZKqwrSJAATo5iTS65BuYxrFsFNPrf7TitM8E76BEBZk0OZBvZxMuOs6Z1qI8YKVK UrHVGFq3NbuPWCdRul9SX3VfOunr9Gv0GABnJ0ET+K7nspax0xqq7zgnM71QEaiaH17IFYGS sG34V7Wo3vyQzsk7qLf9Ajno0DhJ+VX43g8+AjxOMNVrGCt9RNXSBVpyv2AMTlWCdJ5KI6V4 KEzWM4HJm7QlNKE6RPoBxJVbSQLPd9St3h7mxLcne4l7NK9eNgNnneT7QZL8fL//s9K8Ns1W t60uQNYvbhKDG7+/yLcmJgjF74XkGvxCmTA1rW2bsUriM533nG9gAOUFQjURkwI8jvMAEQEA AYkCaAQYEQIACQUCVxvH8AIbAgIpCRBhV5kVtWN2DsFdIAQZAQIABgUCVxvH8AAKCRCH0Jac RAcHBIkHD/9nmfog7X2ZXMzL9ktT++7x+W/QBrSTCTmq8PK+69+INN1ZDOrY8uz6htfTLV9+ e2W6G8/7zIvODuHk7r+yQ585XbplgP0V5Xc8iBHdBgXbqnY5zBrcH+Q/oQ2STalEvaGHqNoD UGyLQ/fiKoLZTPMur57Fy1c9rTuKiSdMgnT0FPfWVDfpR2Ds0gpqWePlRuRGOoCln5GnREA/ 2MW2rWf+CO9kbIR+66j8b4RUJqIK3dWn9xbENh/aqxfonGTCZQ2zC4sLd25DQA4w1itPo+f5 V/SQxuhnlQkTOCdJ7b/mby/pNRz1lsLkjnXueLILj7gNjwTabZXYtL16z24qkDTI1x3g98R/ xunb3/fQwR8FY5/zRvXJq5us/nLvIvOmVwZFkwXc+AF+LSIajqQz9XbXeIP/BDjlBNXRZNdo dVuSU51ENcMcilPr2EUnqEAqeczsCGpnvRCLfVQeSZr2L9N4svNhhfPOEscYhhpHTh0VPyxI pPBNKq+byuYPMyk3nj814NKhImK0O4gTyCK9b+gZAVvQcYAXvSouCnTZeJRrNHJFTgTgu6E0 caxTGgc5zzQHeX67eMzrGomG3ZnIxmd1sAbgvJUDaD2GrYlulfwGWwWyTNbWRvMighVdPkSF 6XFgQaosWxkV0OELLy2N485YrTr2Uq64VKyxpncLh50e2RnyAJ9Za0Dx0yyp44iD1OvHtkEI M5kY0ACeNhCZJvZ5g4C2Lc9fcTHu8jxmEkI= Message-ID: <5f276678-3ab2-ddc8-640c-6dbbe173463c@gmail.com> Date: Thu, 14 Jan 2021 10:52:44 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: heikki.krogerus@linux.intel.com, peterz@infradead.org, grant.likely@arm.com, paulus@samba.org, Frank Rowand , mingo@kernel.org, Marek Szyprowski , sstabellini@kernel.org, Saravana Kannan , Joerg Roedel , rafael.j.wysocki@intel.com, Christoph Hellwig , Bartosz Golaszewski , xen-devel@lists.xenproject.org, Thierry Reding , linux-devicetree , will@kernel.org, Konrad Rzeszutek Wilk , dan.j.williams@intel.com, linuxppc-dev@lists.ozlabs.org, Rob Herring , boris.ostrovsky@oracle.com, Andy Shevchenko , jgross@suse.com, Nicolas Boichat , Greg KH , rdunlap@infradead.org, lkml , Tomasz Figa , iommu@lists.linux-foundation.org, xypron.glpk@gmx.de, Robin Murphy , bauerman@linux.ibm.com Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On 1/14/21 1:08 AM, Claire Chang wrote: > On Wed, Jan 13, 2021 at 7:48 AM Florian Fainelli wrote: >> >> On 1/5/21 7:41 PM, Claire Chang wrote: >>> If a device is not behind an IOMMU, we look up the device node and set >>> up the restricted DMA when the restricted-dma-pool is presented. >>> >>> Signed-off-by: Claire Chang >>> --- >> >> [snip] >> >>> +int of_dma_set_restricted_buffer(struct device *dev) >>> +{ >>> + struct device_node *node; >>> + int count, i; >>> + >>> + if (!dev->of_node) >>> + return 0; >>> + >>> + count = of_property_count_elems_of_size(dev->of_node, "memory-region", >>> + sizeof(phandle)); >> >> You could have an early check for count < 0, along with an error >> message, if that is deemed useful. >> >>> + for (i = 0; i < count; i++) { >>> + node = of_parse_phandle(dev->of_node, "memory-region", i); >>> + if (of_device_is_compatible(node, "restricted-dma-pool")) >> >> And you may want to add here an of_device_is_available(node). A platform >> that provides the Device Tree firmware and try to support multiple >> different SoCs may try to determine if an IOMMU is present, and if it >> is, it could be marking the restriced-dma-pool region with a 'status = >> "disabled"' property, or any variant of that scheme. > > This function is called only when there is no IOMMU present (check in > drivers/of/device.c). I can still add of_device_is_available(node) > here if you think it's helpful. I believe it is, since boot loader can have a shared Device Tree blob skeleton and do various adaptations based on the chip (that's what we do) and adding a status property is much simpler than insertion new nodes are run time. > >> >>> + return of_reserved_mem_device_init_by_idx( >>> + dev, dev->of_node, i); >> >> This does not seem to be supporting more than one memory region, did not >> you want something like instead: >> >> ret = of_reserved_mem_device_init_by_idx(...); >> if (ret) >> return ret; >> > > Yes. This implement only supports one restriced-dma-pool memory region > with the assumption that there is only one memory region with the > compatible string, restricted-dma-pool, in the dts. IIUC, it's similar > to shared-dma-pool. Then if here is such a known limitation it should be both documented and enforced here, you shouldn ot be iterating over all of the phandles that you find, stop at the first one and issue a warning if count > 1? -- Florian