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=-16.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 0F3A2C49EA2 for ; Thu, 17 Jun 2021 09:48:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E78256113C for ; Thu, 17 Jun 2021 09:48:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231834AbhFQJuk (ORCPT ); Thu, 17 Jun 2021 05:50:40 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57228 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229901AbhFQJue (ORCPT ); Thu, 17 Jun 2021 05:50:34 -0400 Received: from mail.kapsi.fi (mail.kapsi.fi [IPv6:2001:67c:1be8::25]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7687AC061574; Thu, 17 Jun 2021 02:48:24 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=kapsi.fi; s=20161220; h=Content-Transfer-Encoding:MIME-Version:Message-Id:Date:Subject :Cc:To:From:Sender:Reply-To:Content-Type:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: In-Reply-To:References:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=zXnOBn26cINm8enzOJszXsNuboJbpqm7HmK6Xcx5VOw=; b=KgSQ53lQn8xks4e1gAkAJZX+Wr qj0982oho/C6iIMo2lRcjqlUKdAkQUlR6CPdMFtTvP69VYxS6EbfrBPHZtDY5U3F55SWDf9qAyRSG vy0i5BgiiTNB5Ge9REAhYOZlhJESkyUCxpQvUV/vMxJxVteDuXhxoKG5rJMtl/U3DtEhcZUo+MECQ EeetpoRppuoYROxokWHZsE7f/y3pI19bEuKE74No71P7UGMNKQvuf7bRGJO+Fc7xA/fdoEMS67miA h98m2LnHx8DQ/iS46bnSvZzZ0G6N/cepfnQWBMYsq5qNhqU1Tm5cx57at5jHGw98bhuuiNpw154NF umN6Sebw==; Received: from dsl-hkibng22-54f986-236.dhcp.inet.fi ([84.249.134.236] helo=toshino.localdomain) by mail.kapsi.fi with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.89) (envelope-from ) id 1ltodH-0000JZ-OC; Thu, 17 Jun 2021 12:48:19 +0300 From: Mikko Perttunen To: arnd@arndb.de, gregkh@linuxfoundation.org Cc: ykaukab@suse.de, linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org, Mikko Perttunen Subject: [PATCH] misc: sram: Only map reserved areas in Tegra SYSRAM Date: Thu, 17 Jun 2021 12:48:04 +0300 Message-Id: <20210617094804.667716-1-mperttunen@nvidia.com> X-Mailer: git-send-email 2.30.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-SA-Exim-Connect-IP: 84.249.134.236 X-SA-Exim-Mail-From: mperttunen@nvidia.com X-SA-Exim-Scanned: No (on mail.kapsi.fi); SAEximRunCond expanded to false Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tegra186 and later, a portion of the SYSRAM may be reserved for use by TZ. Non-TZ memory accesses to this portion, including speculative accesses, trigger SErrors that bring down the system. This does also happen in practice occasionally (due to speculative accesses). To fix the issue, add a flag to the SRAM driver to only map the device tree-specified reserved areas depending on a flag set based on the compatibility string. This would not affect non-Tegra systems that rely on the entire thing being memory mapped. Signed-off-by: Mikko Perttunen --- drivers/misc/sram.c | 108 +++++++++++++++++++++++++++++++------------- drivers/misc/sram.h | 9 ++++ 2 files changed, 86 insertions(+), 31 deletions(-) diff --git a/drivers/misc/sram.c b/drivers/misc/sram.c index 93638ae2753a..a27ffb3dbea8 100644 --- a/drivers/misc/sram.c +++ b/drivers/misc/sram.c @@ -97,7 +97,24 @@ static int sram_add_partition(struct sram_dev *sram, struct sram_reserve *block, struct sram_partition *part = &sram->partition[sram->partitions]; mutex_init(&part->lock); - part->base = sram->virt_base + block->start; + + if (sram->config->map_only_reserved) { + void *virt_base; + + if (sram->no_memory_wc) + virt_base = devm_ioremap_resource(sram->dev, &block->res); + else + virt_base = devm_ioremap_resource_wc(sram->dev, &block->res); + + if (IS_ERR(virt_base)) { + dev_err(sram->dev, "could not map SRAM at %pr\n", &block->res); + return PTR_ERR(virt_base); + } + + part->base = virt_base; + } else { + part->base = sram->virt_base + block->start; + } if (block->pool) { ret = sram_add_pool(sram, block, start, part); @@ -198,6 +215,7 @@ static int sram_reserve_regions(struct sram_dev *sram, struct resource *res) block->start = child_res.start - res->start; block->size = resource_size(&child_res); + block->res = child_res; list_add_tail(&block->list, &reserve_list); if (of_find_property(child, "export", NULL)) @@ -295,15 +313,17 @@ static int sram_reserve_regions(struct sram_dev *sram, struct resource *res) */ cur_size = block->start - cur_start; - dev_dbg(sram->dev, "adding chunk 0x%lx-0x%lx\n", - cur_start, cur_start + cur_size); + if (sram->pool) { + dev_dbg(sram->dev, "adding chunk 0x%lx-0x%lx\n", + cur_start, cur_start + cur_size); - ret = gen_pool_add_virt(sram->pool, - (unsigned long)sram->virt_base + cur_start, - res->start + cur_start, cur_size, -1); - if (ret < 0) { - sram_free_partitions(sram); - goto err_chunks; + ret = gen_pool_add_virt(sram->pool, + (unsigned long)sram->virt_base + cur_start, + res->start + cur_start, cur_size, -1); + if (ret < 0) { + sram_free_partitions(sram); + goto err_chunks; + } } /* next allocation after this reserved block */ @@ -331,40 +351,66 @@ static int atmel_securam_wait(void) 10000, 500000); } +static const struct sram_config default_config = { +}; + +static const struct sram_config atmel_securam_config = { + .init = atmel_securam_wait +}; + +/* + * SYSRAM contains areas that are not accessible by the + * kernel, such as the first 256K that is reserved for TZ. + * Accesses to those areas (including speculative accesses) + * trigger SErrors. As such we must map only the areas of + * SYSRAM specified in the device tree. + */ +static const struct sram_config tegra_sysram_config = { + .map_only_reserved = true, +}; + static const struct of_device_id sram_dt_ids[] = { - { .compatible = "mmio-sram" }, - { .compatible = "atmel,sama5d2-securam", .data = atmel_securam_wait }, + { .compatible = "mmio-sram", .data = &default_config }, + { .compatible = "atmel,sama5d2-securam", .data = &atmel_securam_config }, + { .compatible = "nvidia,tegra186-sysram", .data = &tegra_sysram_config }, + { .compatible = "nvidia,tegra194-sysram", .data = &tegra_sysram_config }, {} }; static int sram_probe(struct platform_device *pdev) { + const struct sram_config *config; struct sram_dev *sram; int ret; struct resource *res; - int (*init_func)(void); + + config = of_device_get_match_data(&pdev->dev); sram = devm_kzalloc(&pdev->dev, sizeof(*sram), GFP_KERNEL); if (!sram) return -ENOMEM; sram->dev = &pdev->dev; + sram->no_memory_wc = of_property_read_bool(pdev->dev.of_node, "no-memory-wc"); + sram->config = config; + + if (!config->map_only_reserved) { + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (sram->no_memory_wc) + sram->virt_base = devm_ioremap_resource(&pdev->dev, res); + else + sram->virt_base = devm_ioremap_resource_wc(&pdev->dev, res); + if (IS_ERR(sram->virt_base)) { + dev_err(&pdev->dev, "could not map SRAM registers\n"); + return PTR_ERR(sram->virt_base); + } - res = platform_get_resource(pdev, IORESOURCE_MEM, 0); - if (of_property_read_bool(pdev->dev.of_node, "no-memory-wc")) - sram->virt_base = devm_ioremap_resource(&pdev->dev, res); - else - sram->virt_base = devm_ioremap_resource_wc(&pdev->dev, res); - if (IS_ERR(sram->virt_base)) { - dev_err(&pdev->dev, "could not map SRAM registers\n"); - return PTR_ERR(sram->virt_base); + sram->pool = devm_gen_pool_create(sram->dev, ilog2(SRAM_GRANULARITY), + NUMA_NO_NODE, NULL); + if (IS_ERR(sram->pool)) + return PTR_ERR(sram->pool); } - sram->pool = devm_gen_pool_create(sram->dev, ilog2(SRAM_GRANULARITY), - NUMA_NO_NODE, NULL); - if (IS_ERR(sram->pool)) - return PTR_ERR(sram->pool); - sram->clk = devm_clk_get(sram->dev, NULL); if (IS_ERR(sram->clk)) sram->clk = NULL; @@ -378,15 +424,15 @@ static int sram_probe(struct platform_device *pdev) platform_set_drvdata(pdev, sram); - init_func = of_device_get_match_data(&pdev->dev); - if (init_func) { - ret = init_func(); + if (config->init) { + ret = config->init(); if (ret) goto err_free_partitions; } - dev_dbg(sram->dev, "SRAM pool: %zu KiB @ 0x%p\n", - gen_pool_size(sram->pool) / 1024, sram->virt_base); + if (sram->pool) + dev_dbg(sram->dev, "SRAM pool: %zu KiB @ 0x%p\n", + gen_pool_size(sram->pool) / 1024, sram->virt_base); return 0; @@ -405,7 +451,7 @@ static int sram_remove(struct platform_device *pdev) sram_free_partitions(sram); - if (gen_pool_avail(sram->pool) < gen_pool_size(sram->pool)) + if (sram->pool && gen_pool_avail(sram->pool) < gen_pool_size(sram->pool)) dev_err(sram->dev, "removed while SRAM allocated\n"); if (sram->clk) diff --git a/drivers/misc/sram.h b/drivers/misc/sram.h index 9c1d21ff7347..d2058d8c8f1d 100644 --- a/drivers/misc/sram.h +++ b/drivers/misc/sram.h @@ -5,6 +5,11 @@ #ifndef __SRAM_H #define __SRAM_H +struct sram_config { + int (*init)(void); + bool map_only_reserved; +}; + struct sram_partition { void __iomem *base; @@ -15,8 +20,11 @@ struct sram_partition { }; struct sram_dev { + const struct sram_config *config; + struct device *dev; void __iomem *virt_base; + bool no_memory_wc; struct gen_pool *pool; struct clk *clk; @@ -29,6 +37,7 @@ struct sram_reserve { struct list_head list; u32 start; u32 size; + struct resource res; bool export; bool pool; bool protect_exec; -- 2.30.1