From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from canpmsgout03.his.huawei.com (canpmsgout03.his.huawei.com [113.46.200.218]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5AD0E32C94A for ; Wed, 20 May 2026 06:37:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=113.46.200.218 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779259050; cv=none; b=GVhDU63tZDk4oRBRGqPZFM2eaUXIpdo9rXZ5fNuJluyE2U46jB+uGEIncAxy7DipVixN7m6eQP4/M34ysTaZPa8EAfIF5+99Bk3G2V96PPJqFWC59L9IifCBg3JnMp9prvS/Yiv7RMEatoLPQI3XCv0I20jw9OpvJEvIql8bKnY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779259050; c=relaxed/simple; bh=Dr/4xDbrG510OQcjwBL+tFBVj+TL+p3PLRpuroJdcow=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=iK2Kin4gZ8EzGTDxWcdL37B40fIT/mpfEekxycu9J1p/52wvV+G6YaBgGukQbWid4JcpRtixCDXkL6sI/mMYjsmEfYzEXgOapgaP3R311BeI1j4Ke/8Y1s4PafJutAOLYCSkwjVYYf/IhCWe4MMGIod7RRU/TwNso1tl4fVgyOc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huawei.com; dkim=pass (1024-bit key) header.d=huawei.com header.i=@huawei.com header.b=JP0H/hcb; arc=none smtp.client-ip=113.46.200.218 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=huawei.com header.i=@huawei.com header.b="JP0H/hcb" dkim-signature: v=1; a=rsa-sha256; d=huawei.com; s=dkim; c=relaxed/relaxed; q=dns/txt; h=From; bh=A+9GMhHowlViOnH7+R9rmivmHqr2sB1gmzk/fG1Uco0=; b=JP0H/hcbSFdYwsZD0y/WqrbQ/tzGa8skOHjGDlyMM26YfHsUUglbpIbKwyZp3qvRLTM/vFpTo 3HCy15p48E/Drxodqr2XwBNXeS97tlHjEveIXS+m62aOKUO8yxOEOfK+UDypixYU0bCkWRDf4gc v5gacV3Ab6oangMQznj6aY8= Received: from mail.maildlp.com (unknown [172.19.163.104]) by canpmsgout03.his.huawei.com (SkyGuard) with ESMTPS id 4gL1qg5S4VzpT03; Wed, 20 May 2026 14:30:07 +0800 (CST) Received: from kwepemj200003.china.huawei.com (unknown [7.202.194.15]) by mail.maildlp.com (Postfix) with ESMTPS id 5915B4048F; Wed, 20 May 2026 14:37:21 +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; Wed, 20 May 2026 14:37:20 +0800 From: Qinxin Xia To: , , , CC: , , , , , , , , , Subject: [PATCH 5/5] iommu/arm-smmu-v3: Add Context Descriptor display to debugfs Date: Wed, 20 May 2026 14:37:11 +0800 Message-ID: <20260520063714.2440584-5-xiaqinxin@huawei.com> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20260328101706.3448655-1-xiaqinxin@huawei.com> References: <20260328101706.3448655-1-xiaqinxin@huawei.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit X-ClientProxiedBy: kwepems500002.china.huawei.com (7.221.188.17) To kwepemj200003.china.huawei.com (7.202.194.15) 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 | 101 ++++++++++++++++++ 1 file changed, 101 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 9babc7d640fd..567749de5537 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 */ @@ -303,6 +310,97 @@ 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; + u32 max_ssids, ssid; + + guard(mutex)(&arm_smmu_asid_lock); + + master = dev_iommu_priv_get(dev); + if (!master) { + seq_puts(seq, "No master data\n"); + return 0; + } + + 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); + } + } + + return 0; +} + +static int smmu_debugfs_cd_open(struct inode *inode, struct file *file) +{ + struct device *dev = inode->i_private; + int ret; + + if (!dev || !get_device(dev)) + return -ENODEV; + + ret = single_open(file, smmu_debugfs_cd_show, dev); + if (ret) + put_device(dev); + + return ret; +} + +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 * @smmu: SMMU device @@ -373,6 +471,9 @@ int arm_smmu_debugfs_create_stream_table(struct arm_smmu_device *smmu, kfree(full_path); } } + + /* Create CD file to dump all valid Context Descriptors */ + debugfs_create_file("cd", 0444, dev_dir, dev, &smmu_debugfs_cd_fops); } kfree(path); -- 2.33.0