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=-19.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 7D5BFC43611 for ; Wed, 5 May 2021 16:51:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5A8E36141B for ; Wed, 5 May 2021 16:51:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235974AbhEEQwb (ORCPT ); Wed, 5 May 2021 12:52:31 -0400 Received: from mail.kernel.org ([198.145.29.99]:49996 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235842AbhEEQpH (ORCPT ); Wed, 5 May 2021 12:45:07 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 1C8A66142F; Wed, 5 May 2021 16:35:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1620232549; bh=L9Fh6FiWjtyOYGHCrMPfyT8MFcvxiBflcyQyZc5AxaM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=TQrwd/IF8aohczlbQ2uOXIqLSP8T7mNfjnt0zLNC5JlwowG/H8Nu+unBmQ2o7zeVC DIUH/el1tFs6jmj0wRovsy0fzTC6/sd0XqneILD7ZVv2eV8j9L9lY7Hy6xS/mbed9x u9g7qJf2cuQWGz+lLcBLzGjtmhLOF0slrT1CWBIqWg0KKCa4xTuiYPLALbBzUD1nA9 PyQqItMYQ5s4+qtE47bAkeRJmsHWq12t/K2BssCoUkUr+SZeyziPSfS7Z010ro/Q1x eNIr0aZcyWKE2iUb8XAEnuGrYyI3u5bmp3jmJYvD6+4wN3iCz0t/YG9kFo3UDxK6lp Jiow33MCpXgGA== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Paul Menzel , Tj , Shuah Khan , Alexander Monakov , David Coe , Suravee Suthikulpanit , Joerg Roedel , Sasha Levin , iommu@lists.linux-foundation.org Subject: [PATCH AUTOSEL 5.11 066/104] Revert "iommu/amd: Fix performance counter initialization" Date: Wed, 5 May 2021 12:33:35 -0400 Message-Id: <20210505163413.3461611-66-sashal@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210505163413.3461611-1-sashal@kernel.org> References: <20210505163413.3461611-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Paul Menzel [ Upstream commit 715601e4e36903a653cd4294dfd3ed0019101991 ] This reverts commit 6778ff5b21bd8e78c8bd547fd66437cf2657fd9b. The original commit tries to address an issue, where PMC power-gating causing the IOMMU PMC pre-init test to fail on certain desktop/mobile platforms where the power-gating is normally enabled. There have been several reports that the workaround still does not guarantee to work, and can add up to 100 ms (on the worst case) to the boot process on certain platforms such as the MSI B350M MORTAR with AMD Ryzen 3 2200G. Therefore, revert this commit as a prelude to removing the pre-init test. Link: https://lore.kernel.org/linux-iommu/alpine.LNX.3.20.13.2006030935570.3181@monopod.intra.ispras.ru/ Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=201753 Cc: Tj (Elloe Linux) Cc: Shuah Khan Cc: Alexander Monakov Cc: David Coe Signed-off-by: Paul Menzel Signed-off-by: Suravee Suthikulpanit Link: https://lore.kernel.org/r/20210409085848.3908-2-suravee.suthikulpanit@amd.com Signed-off-by: Joerg Roedel Signed-off-by: Sasha Levin --- drivers/iommu/amd/init.c | 45 ++++++++++------------------------------ 1 file changed, 11 insertions(+), 34 deletions(-) diff --git a/drivers/iommu/amd/init.c b/drivers/iommu/amd/init.c index 78339b0bb8e5..7720dcfa2b29 100644 --- a/drivers/iommu/amd/init.c +++ b/drivers/iommu/amd/init.c @@ -12,7 +12,6 @@ #include #include #include -#include #include #include #include @@ -255,8 +254,6 @@ static enum iommu_init_state init_state = IOMMU_START_STATE; static int amd_iommu_enable_interrupts(void); static int __init iommu_go_to_state(enum iommu_init_state state); static void init_device_table_dma(void); -static int iommu_pc_get_set_reg(struct amd_iommu *iommu, u8 bank, u8 cntr, - u8 fxn, u64 *value, bool is_write); static bool amd_iommu_pre_enabled = true; @@ -1715,11 +1712,13 @@ static int __init init_iommu_all(struct acpi_table_header *table) return 0; } -static void __init init_iommu_perf_ctr(struct amd_iommu *iommu) +static int iommu_pc_get_set_reg(struct amd_iommu *iommu, u8 bank, u8 cntr, + u8 fxn, u64 *value, bool is_write); + +static void init_iommu_perf_ctr(struct amd_iommu *iommu) { - int retry; struct pci_dev *pdev = iommu->dev; - u64 val = 0xabcd, val2 = 0, save_reg, save_src; + u64 val = 0xabcd, val2 = 0, save_reg = 0; if (!iommu_feature(iommu, FEATURE_PC)) return; @@ -1727,39 +1726,17 @@ static void __init init_iommu_perf_ctr(struct amd_iommu *iommu) amd_iommu_pc_present = true; /* save the value to restore, if writable */ - if (iommu_pc_get_set_reg(iommu, 0, 0, 0, &save_reg, false) || - iommu_pc_get_set_reg(iommu, 0, 0, 8, &save_src, false)) - goto pc_false; - - /* - * Disable power gating by programing the performance counter - * source to 20 (i.e. counts the reads and writes from/to IOMMU - * Reserved Register [MMIO Offset 1FF8h] that are ignored.), - * which never get incremented during this init phase. - * (Note: The event is also deprecated.) - */ - val = 20; - if (iommu_pc_get_set_reg(iommu, 0, 0, 8, &val, true)) + if (iommu_pc_get_set_reg(iommu, 0, 0, 0, &save_reg, false)) goto pc_false; /* Check if the performance counters can be written to */ - val = 0xabcd; - for (retry = 5; retry; retry--) { - if (iommu_pc_get_set_reg(iommu, 0, 0, 0, &val, true) || - iommu_pc_get_set_reg(iommu, 0, 0, 0, &val2, false) || - val2) - break; - - /* Wait about 20 msec for power gating to disable and retry. */ - msleep(20); - } - - /* restore */ - if (iommu_pc_get_set_reg(iommu, 0, 0, 0, &save_reg, true) || - iommu_pc_get_set_reg(iommu, 0, 0, 8, &save_src, true)) + if ((iommu_pc_get_set_reg(iommu, 0, 0, 0, &val, true)) || + (iommu_pc_get_set_reg(iommu, 0, 0, 0, &val2, false)) || + (val != val2)) goto pc_false; - if (val != val2) + /* restore */ + if (iommu_pc_get_set_reg(iommu, 0, 0, 0, &save_reg, true)) goto pc_false; pci_info(pdev, "IOMMU performance counters supported\n"); -- 2.30.2