Re: [RFC PATCH v2 10/10] iommu/arm-smmu-v3: Invoke pm_runtime before hw access

[kernel test robot <lkp@intel.com>]

Hi Pranjal,

[This is a private test report for your RFC patch.]
kernel test robot noticed the following build warnings:

[auto build test WARNING on arm-perf/for-next/perf]
[also build test WARNING on linus/master v6.15-rc2 next-20250417]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Pranjal-Shrivastava/iommu-arm-smmu-v3-Refactor-arm_smmu_setup_irqs/20250419-073729
base:   https://git.kernel.org/pub/scm/linux/kernel/git/will/linux.git for-next/perf
patch link:    https://lore.kernel.org/r/20250418233409.3926715-11-praan%40google.com
patch subject: [RFC PATCH v2 10/10] iommu/arm-smmu-v3: Invoke pm_runtime before hw access
config: arm64-randconfig-001-20250419 (https://download.01.org/0day-ci/archive/20250419/202504192248.FUDmPe37-lkp@intel.com/config)
compiler: aarch64-linux-gcc (GCC) 7.5.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250419/202504192248.FUDmPe37-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202504192248.FUDmPe37-lkp@intel.com/

All warnings (new ones prefixed by >>):

   drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-iommufd.c: In function 'arm_smmu_attach_dev_nested':
>> drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-iommufd.c:150:26: warning: unused variable 'smmu' [-Wunused-variable]
     struct arm_smmu_device *smmu = master->smmu;
                             ^~~~


vim +/smmu +150 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-iommufd.c

   138	
   139	static int arm_smmu_attach_dev_nested(struct iommu_domain *domain,
   140					      struct device *dev)
   141	{
   142		struct arm_smmu_nested_domain *nested_domain =
   143			to_smmu_nested_domain(domain);
   144		struct arm_smmu_master *master = dev_iommu_priv_get(dev);
   145		struct arm_smmu_attach_state state = {
   146			.master = master,
   147			.old_domain = iommu_get_domain_for_dev(dev),
   148			.ssid = IOMMU_NO_PASID,
   149		};
 > 150		struct arm_smmu_device *smmu = master->smmu;
   151		struct arm_smmu_ste ste;
   152		int ret;
   153	
   154		if (nested_domain->vsmmu->smmu != master->smmu)
   155			return -EINVAL;
   156		if (arm_smmu_ssids_in_use(&master->cd_table))
   157			return -EBUSY;
   158	
   159		mutex_lock(&arm_smmu_asid_lock);
   160		/*
   161		 * The VM has to control the actual ATS state at the PCI device because
   162		 * we forward the invalidations directly from the VM. If the VM doesn't
   163		 * think ATS is on it will not generate ATC flushes and the ATC will
   164		 * become incoherent. Since we can't access the actual virtual PCI ATS
   165		 * config bit here base this off the EATS value in the STE. If the EATS
   166		 * is set then the VM must generate ATC flushes.
   167		 */
   168		state.disable_ats = !nested_domain->enable_ats;
   169		ret = arm_smmu_attach_prepare(&state, domain);
   170		if (ret) {
   171			mutex_unlock(&arm_smmu_asid_lock);
   172			return ret;
   173		}
   174	
   175		arm_smmu_make_nested_domain_ste(&ste, master, nested_domain,
   176						state.ats_enabled);
   177		arm_smmu_install_ste_for_dev(master, &ste);
   178		arm_smmu_attach_commit(&state);
   179		mutex_unlock(&arm_smmu_asid_lock);
   180		return 0;
   181	}
   182	

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