From: Qinxin Xia <xiaqinxin@huawei•com>
To: Nicolin Chen <nicolinc@nvidia•com>
Cc: <robin.murphy@arm•com>, <will@kernel•org>, <jpb@kernel•org>,
<linux-arm-kernel@lists•infradead.org>, <iommu@lists•linux.dev>,
<wangzhou1@hisilicon•com>, <prime.zeng@hisilicon•com>,
<fanghao11@huawei•com>, <jonathan.cameron@huawei•com>,
<wuyifan50@huawei•com>, <linuxarm@huawei•com>
Subject: Re: [RFC PATCH v2 1/5] iommu/arm-smmu-v3: Add basic debugfs framework
Date: Thu, 2 Apr 2026 11:50:54 +0800 [thread overview]
Message-ID: <b0e67dac-a95f-4b8f-b4c6-3e992b66a780@huawei.com> (raw)
In-Reply-To: <acpUoZ7wx9gdT5BG@nvidia.com>
On 2026/3/30 18:46:57, Nicolin Chen <nicolinc@nvidia•com> wrote:
> On Sat, Mar 28, 2026 at 06:17:02PM +0800, Qinxin Xia wrote:
>> Add basic debugfs framework for ARM SMMUv3 driver.This creates the
>
> Needs a space after "."
>
>> +static int smmu_debugfs_capabilities_show(struct seq_file *seq, void *unused)
>> +{
>> + struct arm_smmu_device *smmu = seq->private;
>> +
>> + if (!smmu) {
>> + seq_puts(seq, "SMMU not available\n");
>> + return 0;
>> + }
>> +
>> + seq_puts(seq, "SMMUv3 Capabilities:\n");
>> + seq_printf(seq, " Stage1 Translation: %s\n",
>> + smmu->features & ARM_SMMU_FEAT_TRANS_S1 ? "Yes" : "No");
>> + seq_printf(seq, " Stage2 Translation: %s\n",
>> + smmu->features & ARM_SMMU_FEAT_TRANS_S2 ? "Yes" : "No");
>> + seq_printf(seq, " Coherent Walk: %s\n",
>> + smmu->features & ARM_SMMU_FEAT_COHERENCY ? "Yes" : "No");
>> + seq_printf(seq, " ATS Support: %s\n",
>> + smmu->features & ARM_SMMU_FEAT_ATS ? "Yes" : "No");
>> + seq_printf(seq, " PRI Support: %s\n",
>> + smmu->features & ARM_SMMU_FEAT_PRI ? "Yes" : "No");
>> + seq_printf(seq, " Stream Table Size: %d\n", 1 << smmu->sid_bits);
>> + seq_printf(seq, " Command Queue Depth: %d\n",
>> + 1 << smmu->cmdq.q.llq.max_n_shift);
>> + seq_printf(seq, " Event Queue Depth: %d\n",
>> + 1 << smmu->evtq.q.llq.max_n_shift);
>
> Nit: should we do all sizes or all depths? Any good reason to mix
> them here?
>
Stream Table is a table, not a queue, so 'Size' is more appropriate;
queues use 'Depth'. But I can change to unify if preferred.
>> +/**
>> + * arm_smmu_debugfs_remove() - Clean up debugfs entries for an SMMU device
>> + * @smmu: SMMU device
>> + *
>> + * This function removes the debugfs directories created by setup.
>> + */
>> +void arm_smmu_debugfs_remove(struct arm_smmu_device *smmu)
>> +{
>> + struct arm_smmu_debugfs *debugfs;
>> +
>> + scoped_guard(mutex, &arm_smmu_debugfs_lock) {
>
> It could be just normal guard().
>
>> diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
>> index 4d00d796f078..cbb3fccc501b 100644
>> --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
>> +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
>> @@ -4904,6 +4904,15 @@ static int arm_smmu_device_probe(struct platform_device *pdev)
>> /* Check for RMRs and install bypass STEs if any */
>> arm_smmu_rmr_install_bypass_ste(smmu);
>>
>> +#ifdef CONFIG_ARM_SMMU_V3_DEBUGFS
>> + char name[32];
>
> This could be moved to the top, as iommu_device_sysfs_add() can use
> it, whether CONFIG_ARM_SMMU_V3_DEBUGFS=y or =n.
>
>> + snprintf(name, sizeof(name), "smmu3.%pa", &ioaddr);
>
> And this could be moved after ioaddr gets a copy from res->start.
>
>>
>> +#ifdef CONFIG_ARM_SMMU_V3_DEBUGFS
>> +struct arm_smmu_debugfs {
>> + struct dentry *smmu_dir;
>
> A personal preference: for new structures, maybe drop those tabs?
>
>> /* An SMMUv3 instance */
>> struct arm_smmu_device {
>> struct device *dev;
>> @@ -803,6 +813,11 @@ struct arm_smmu_device {
>>
>> struct rb_root streams;
>> struct mutex streams_mutex;
>> +
>> +#ifdef CONFIG_ARM_SMMU_V3_DEBUGFS
>> + /* DebugFS Info */
>
> Doesn't seem very useful. I'd drop it.
>
>> + struct arm_smmu_debugfs *debugfs;
>> +#endif
>
> Nicolin
>
--
Thanks,
Qinxin
next prev parent reply other threads:[~2026-04-02 3:51 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-03-28 10:17 [RFC PATCH v2 0/5] Add debugfs support for ARM SMMUv3 Qinxin Xia
2026-03-28 10:17 ` [RFC PATCH v2 1/5] iommu/arm-smmu-v3: Add basic debugfs framework Qinxin Xia
2026-03-30 10:46 ` Nicolin Chen
2026-04-02 3:50 ` Qinxin Xia [this message]
2026-03-28 10:17 ` [RFC PATCH v2 2/5] iommu/arm-smmu-v3: Add register display to debugfs Qinxin Xia
2026-03-30 11:25 ` Nicolin Chen
2026-03-28 10:17 ` [RFC PATCH v2 3/5] iommu/arm-smmu-v3: Add Stream Table Entry " Qinxin Xia
2026-04-04 5:43 ` Nicolin Chen
2026-03-28 10:17 ` [RFC PATCH v2 4/5] iommu/arm-smmu-v3: Add device symlink in stream table debugfs Qinxin Xia
2026-03-28 10:17 ` [RFC PATCH v2 5/5] iommu/arm-smmu-v3: Add Context Descriptor display to debugfs Qinxin Xia
2026-05-20 6:37 ` [PATCH 0/5] Add debugfs support for ARM SMMUv3 Qinxin Xia
2026-05-20 6:37 ` [PATCH 1/5] iommu/arm-smmu-v3: Add basic debugfs framework Qinxin Xia
2026-05-27 0:41 ` Nicolin Chen
2026-05-20 6:37 ` [PATCH 2/5] iommu/arm-smmu-v3: Add register display to debugfs Qinxin Xia
2026-05-27 1:28 ` Nicolin Chen
2026-05-20 6:37 ` [PATCH 3/5] iommu/arm-smmu-v3: Add Stream Table Entry " Qinxin Xia
2026-05-27 2:18 ` Nicolin Chen
2026-05-27 2:43 ` Nicolin Chen
2026-05-20 6:37 ` [PATCH 4/5] iommu/arm-smmu-v3: Add device symlink in stream table debugfs Qinxin Xia
2026-05-20 6:37 ` [PATCH 5/5] iommu/arm-smmu-v3: Add Context Descriptor display to debugfs Qinxin Xia
2026-05-27 2:40 ` Nicolin Chen
2026-05-27 0:07 ` [PATCH 0/5] Add debugfs support for ARM SMMUv3 Nicolin Chen
-- strict thread matches above, loose matches on Subject: below --
2026-03-28 10:09 [RFC PATCH v2 " Qinxin Xia
2026-03-28 10:09 ` [RFC PATCH v2 1/5] iommu/arm-smmu-v3: Add basic debugfs framework Qinxin Xia
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