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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id A380E10F3DE1 for ; Sat, 28 Mar 2026 10:10:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:CC: To:From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=35Vdxw+bGikUGARyshD29d8hmxPEOshopH4zQVVJEkw=; b=Y/wayCqrK7EKVORu6EvTJJArfq 6K+ZNnhkBjT0Ou+Kzsu8uLnbD0cQRdMhOVbR3ytVY5lzrvlmpDcLTh+JRorCvX7SIG9TLzyWJrRKH PZjjgVMBromBO8/kir+Ix1kxNzdmqBCsYw8JlBg35ZcqmxgbsvssOCD0vLYwXr/kOM3K8SNUDVjVu T8V9DfyN94XqL5sBNB5F3PNjvko3qzp/ljR4OX+fBHDhkXH3sN2Zvlp9clgAmd+PrW7HimtzIWFZQ WBgJBMvvTYNIbUBqUgxnG3+vb/FSnF7udIt2I53kChFOZILXf9fMiEz5xElc5R0aQzJuvacxftGfp LRQsowMw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1w6QcV-00000008oTf-47oF; Sat, 28 Mar 2026 10:10:19 +0000 Received: from canpmsgout11.his.huawei.com ([113.46.200.226]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1w6QcG-00000008oNL-0Xsn for linux-arm-kernel@lists.infradead.org; Sat, 28 Mar 2026 10:10:08 +0000 dkim-signature: v=1; a=rsa-sha256; d=huawei.com; s=dkim; c=relaxed/relaxed; q=dns/txt; h=From; bh=35Vdxw+bGikUGARyshD29d8hmxPEOshopH4zQVVJEkw=; b=s49vGdAHRwvtDhPiphC6xoXo/WG2C5Df4WFVvligxTKt1X6zBh5vr+jG+n7Z+guWwk/9RoNel MvljwNHxvht3ChIOXlBNkn+m6mr44/MOYkxxABpG2vxTAsLpxite/xkdksIG2DoMnSMBhG1xLJB uApiIXqzmtFkytkRb2rItXc= Received: from mail.maildlp.com (unknown [172.19.163.163]) by canpmsgout11.his.huawei.com (SkyGuard) with ESMTPS id 4fjY4g2CLtzKm5B; Sat, 28 Mar 2026 18:03:47 +0800 (CST) Received: from kwepemj200003.china.huawei.com (unknown [7.202.194.15]) by mail.maildlp.com (Postfix) with ESMTPS id 8A78640565; Sat, 28 Mar 2026 18:09:56 +0800 (CST) Received: from localhost.huawei.com (10.90.31.46) by kwepemj200003.china.huawei.com (7.202.194.15) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.11; Sat, 28 Mar 2026 18:09:55 +0800 From: Qinxin Xia To: , , , CC: , , , , , , , , Subject: [RFC PATCH v2 5/5] iommu/arm-smmu-v3: Add Context Descriptor display to debugfs Date: Sat, 28 Mar 2026 18:09:53 +0800 Message-ID: <20260328100953.3441915-6-xiaqinxin@huawei.com> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20260328100953.3441915-1-xiaqinxin@huawei.com> References: <20260328100953.3441915-1-xiaqinxin@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit X-Originating-IP: [10.90.31.46] X-ClientProxiedBy: kwepems500001.china.huawei.com (7.221.188.70) To kwepemj200003.china.huawei.com (7.202.194.15) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260328_031004_955668_8543A037 X-CRM114-Status: GOOD ( 13.80 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Add Context Descriptor (CD) display functionality to debugfs. This allow inspecting CD contents for all Substream IDs including: - CD validity and translation parameters - TTBR0 and TCR configurations - Raw CD data /sys/kernel/debug/iommu/arm_smmu_v3/smmu0/stream_table/ └── / ├─── ste ├─── cd └─── Signed-off-by: Qinxin Xia --- .../arm/arm-smmu-v3/arm-smmu-v3-debugfs.c | 94 +++++++++++++++++++ 1 file changed, 94 insertions(+) diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-debugfs.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-debugfs.c index dbcc8fce6d8e..501437432809 100644 --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-debugfs.c +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-debugfs.c @@ -10,6 +10,7 @@ * └── stream_table * └─── / # Stream ID * ├─── ste # Stream Table Entry + * ├── cd # Context Descriptor * └── # Symlink to device sysfs directory * * The capabilities file provides detailed information about: @@ -26,6 +27,12 @@ * - Stage 1 and Stage 2 context pointers * - Raw STE data * + * CD Information Displayed: + * - T0SZ: Input address space size configuration + * - EPD0/EPD1: Stage 1 translation enable flags + * - TTBR0: Stage 1 translation table base address + * - Raw Data: Complete CD structure in hexadecimal format + * Copyright (C) 2026 HiSilicon Limited. * Author: Qinxin Xia */ @@ -284,6 +291,91 @@ static const struct file_operations smmu_debugfs_ste_fops = { .release = smmu_debugfs_ste_release, }; +/** + * smmu_debug_dump_cd() - Dump a single Context Descriptor + * @seq: seq_file to write to + * @cd: pointer to the Context Descriptor to dump + */ +static void smmu_debug_dump_cd(struct seq_file *seq, struct arm_smmu_cd *cd) +{ + u64 data; + int i; + + /* CD 0 */ + data = le64_to_cpu(cd->data[0]); + seq_printf(seq, " T0SZ: 0x%llx\n", data & CTXDESC_CD_0_TCR_T0SZ); + seq_printf(seq, " EPD0: %s\n", data & CTXDESC_CD_0_TCR_EPD0 ? "Yes" : "No"); + seq_printf(seq, " EPD1: %s\n", data & CTXDESC_CD_0_TCR_EPD1 ? "Yes" : "No"); + + /* CD 1 */ + data = le64_to_cpu(cd->data[1]); + seq_printf(seq, " TTBR0: 0x%016llx\n", data & CTXDESC_CD_1_TTB0_MASK); + + /* Display raw CD data */ + seq_puts(seq, " Raw Data:\n"); + for (i = 0; i < CTXDESC_CD_DWORDS; i++) + seq_printf(seq, " CD[%d]: 0x%016llx\n", i, + le64_to_cpu(cd->data[i])); +} + +static int smmu_debugfs_cd_show(struct seq_file *seq, void *unused) +{ + struct device *dev = seq->private; + struct arm_smmu_master *master = dev_iommu_priv_get(dev); + u32 max_ssids, ssid; + + if (!master) { + seq_puts(seq, "No master data\n"); + return 0; + } + + mutex_lock(&arm_smmu_asid_lock); + max_ssids = 1 << master->ssid_bits; + seq_printf(seq, "Context Descriptors for device (max SSIDs: %u):\n", + max_ssids); + + for (ssid = 0; ssid < max_ssids; ssid++) { + struct arm_smmu_cd *cd = arm_smmu_get_cd_ptr(master, ssid); + + if (cd && (le64_to_cpu(cd->data[0]) & CTXDESC_CD_0_V)) { + seq_printf(seq, "\n--- SSID %u ---\n", ssid); + smmu_debug_dump_cd(seq, cd); + } + } + + mutex_unlock(&arm_smmu_asid_lock); + return 0; +} + +static int smmu_debugfs_cd_open(struct inode *inode, struct file *file) +{ + struct device *dev = inode->i_private; + + if (!dev || !get_device(dev)) + return -ENODEV; + + return single_open(file, smmu_debugfs_cd_show, dev); +} + +static int smmu_debugfs_cd_release(struct inode *inode, struct file *file) +{ + struct seq_file *seq = file->private_data; + struct device *dev = seq->private; + + single_release(inode, file); + if (dev) + put_device(dev); + return 0; +} + +static const struct file_operations smmu_debugfs_cd_fops = { + .owner = THIS_MODULE, + .open = smmu_debugfs_cd_open, + .read = seq_read, + .llseek = seq_lseek, + .release = smmu_debugfs_cd_release, +}; + /** * arm_smmu_debugfs_create_stream_table() - Create debugfs entries for stream table * @dev: device to create entries for @@ -348,6 +440,8 @@ int arm_smmu_debugfs_create_stream_table(struct device *dev, } kfree(path); + /* Create CD file to dump all valid Context Descriptors */ + debugfs_create_file("cd", 0444, dev_dir, dev, &smmu_debugfs_cd_fops); } return 0; -- 2.33.0