Re: [RESEND PATCH 1/4] iommu/arm-smmu-v3: Add support for ECMDQ register mode

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

Hi Tanmay,

kernel test robot noticed the following build warnings:

[auto build test WARNING on v6.5-rc2]
[also build test WARNING on linus/master next-20230728]
[cannot apply to joro-iommu/next]
[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/Tanmay-Jagdale/iommu-arm-smmu-v3-Add-support-for-ECMDQ-register-mode/20230721-143913
base:   v6.5-rc2
patch link:    https://lore.kernel.org/r/20230721063513.33431-2-tanmay%40marvell.com
patch subject: [RESEND PATCH 1/4] iommu/arm-smmu-v3: Add support for ECMDQ register mode
config: arm64-randconfig-r032-20230727 (https://download.01.org/0day-ci/archive/20230728/202307281657.K3A7kRax-lkp@intel.com/config)
compiler: clang version 17.0.0 (https://github.com/llvm/llvm-project.git 4a5ac14ee968ff0ad5d2cc1ffa0299048db4c88a)
reproduce: (https://download.01.org/0day-ci/archive/20230728/202307281657.K3A7kRax-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/202307281657.K3A7kRax-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c:3619:39: warning: variable 'pre_addr' is uninitialized when used here [-Wuninitialized]
    3619 |                 if (i && ((val & ECMDQ_CP_ADDR) != (pre_addr + ECMDQ_CP_RRESET_SIZE))) {
         |                                                     ^~~~~~~~
   include/linux/compiler.h:55:47: note: expanded from macro 'if'
      55 | #define if(cond, ...) if ( __trace_if_var( !!(cond , ## __VA_ARGS__) ) )
         |                                               ^~~~
   include/linux/compiler.h:57:52: note: expanded from macro '__trace_if_var'
      57 | #define __trace_if_var(cond) (__builtin_constant_p(cond) ? (cond) : __trace_if_value(cond))
         |                                                    ^~~~
   drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c:3610:20: note: initialize the variable 'pre_addr' to silence this warning
    3610 |                 u64 val, pre_addr;
         |                                  ^
         |                                   = 0
   1 warning generated.


vim +/pre_addr +3619 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c

  3588	
  3589	static int arm_smmu_ecmdq_probe(struct arm_smmu_device *smmu)
  3590	{
  3591		int ret, cpu;
  3592		u32 i, nump, numq, gap;
  3593		u32 reg, shift_increment;
  3594		u64 addr, smmu_dma_base;
  3595		void __iomem *cp_regs, *cp_base;
  3596	
  3597		/* IDR6 */
  3598		reg = readl_relaxed(smmu->base + ARM_SMMU_IDR6);
  3599		nump = 1 << FIELD_GET(IDR6_LOG2NUMP, reg);
  3600		numq = 1 << FIELD_GET(IDR6_LOG2NUMQ, reg);
  3601		smmu->nr_ecmdq = nump * numq;
  3602		gap = ECMDQ_CP_RRESET_SIZE >> FIELD_GET(IDR6_LOG2NUMQ, reg);
  3603	
  3604		smmu_dma_base = (vmalloc_to_pfn(smmu->base) << PAGE_SHIFT);
  3605		cp_regs = ioremap(smmu_dma_base + ARM_SMMU_ECMDQ_CP_BASE, PAGE_SIZE);
  3606		if (!cp_regs)
  3607			return -ENOMEM;
  3608	
  3609		for (i = 0; i < nump; i++) {
  3610			u64 val, pre_addr;
  3611	
  3612			val = readq_relaxed(cp_regs + 32 * i);
  3613			if (!(val & ECMDQ_CP_PRESET)) {
  3614				iounmap(cp_regs);
  3615				dev_err(smmu->dev, "ecmdq control page %u is memory mode\n", i);
  3616				return -EFAULT;
  3617			}
  3618	
> 3619			if (i && ((val & ECMDQ_CP_ADDR) != (pre_addr + ECMDQ_CP_RRESET_SIZE))) {
  3620				iounmap(cp_regs);
  3621				dev_err(smmu->dev, "ecmdq_cp memory region is not contiguous\n");
  3622				return -EFAULT;
  3623			}
  3624	
  3625			pre_addr = val & ECMDQ_CP_ADDR;
  3626		}
  3627	
  3628		addr = readl_relaxed(cp_regs) & ECMDQ_CP_ADDR;
  3629		iounmap(cp_regs);
  3630	
  3631		cp_base = devm_ioremap(smmu->dev, smmu_dma_base + addr, ECMDQ_CP_RRESET_SIZE * nump);
  3632		if (!cp_base)
  3633			return -ENOMEM;
  3634	
  3635		smmu->ecmdq = devm_alloc_percpu(smmu->dev, struct arm_smmu_ecmdq *);
  3636		if (!smmu->ecmdq)
  3637			return -ENOMEM;
  3638	
  3639		ret = arm_smmu_ecmdq_layout(smmu);
  3640		if (ret)
  3641			return ret;
  3642	
  3643		shift_increment = order_base_2(num_possible_cpus() / smmu->nr_ecmdq);
  3644	
  3645		addr = 0;
  3646		for_each_possible_cpu(cpu) {
  3647			struct arm_smmu_ecmdq *ecmdq;
  3648			struct arm_smmu_queue *q;
  3649	
  3650			ecmdq = *per_cpu_ptr(smmu->ecmdq, cpu);
  3651			ecmdq->base = cp_base + addr;
  3652	
  3653			q = &ecmdq->cmdq.q;
  3654	
  3655			q->llq.max_n_shift = ECMDQ_MAX_SZ_SHIFT + shift_increment;
  3656			ret = arm_smmu_init_one_queue(smmu, q, ecmdq->base, ARM_SMMU_ECMDQ_PROD,
  3657					ARM_SMMU_ECMDQ_CONS, CMDQ_ENT_DWORDS, "ecmdq");
  3658			if (ret)
  3659				return ret;
  3660	
  3661			q->ecmdq_prod = ECMDQ_PROD_EN;
  3662			rwlock_init(&q->ecmdq_lock);
  3663	
  3664			ret = arm_smmu_ecmdq_init(&ecmdq->cmdq);
  3665			if (ret) {
  3666				dev_err(smmu->dev, "ecmdq[%d] init failed\n", i);
  3667				return ret;
  3668			}
  3669	
  3670			addr += gap;
  3671		}
  3672	
  3673		return 0;
  3674	}
  3675	

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