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From: kernel test robot <lkp@intel.com>
To: Vasant Hegde <vasant.hegde@amd.com>
Cc: oe-kbuild-all@lists.linux.dev, iommu@lists.linux.dev,
	Joerg Roedel <jroedel@suse.de>, Jason Gunthorpe <jgg@nvidia.com>,
	Jerry Snitselaar <jsnitsel@redhat.com>
Subject: [joro-iommu:x86/amd 16/19] drivers/iommu/amd/iommu.c:829:21: warning: variable 'entry' set but not used
Date: Sat, 7 Oct 2023 11:20:35 +0800	[thread overview]
Message-ID: <202310071103.BYatoc0b-lkp@intel.com> (raw)

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu.git x86/amd
head:   189116d5ad54eee2bab82c5f12e837912fc0b4c4
commit: d55b0d2e075ad32d560cdd35a2016973fda52ed6 [16/19] iommu/amd: Remove PPR support
config: x86_64-randconfig-003-20231007 (https://download.01.org/0day-ci/archive/20231007/202310071103.BYatoc0b-lkp@intel.com/config)
compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231007/202310071103.BYatoc0b-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/202310071103.BYatoc0b-lkp@intel.com/

All warnings (new ones prefixed by >>):

   drivers/iommu/amd/iommu.c: In function 'iommu_poll_ppr_log':
>> drivers/iommu/amd/iommu.c:829:21: warning: variable 'entry' set but not used [-Wunused-but-set-variable]
     829 |                 u64 entry[2];
         |                     ^~~~~


vim +/entry +829 drivers/iommu/amd/iommu.c

90008ee4b811c9 arch/x86/kernel/amd_iommu.c Joerg Roedel 2008-09-09  816  
72e1dcc4192288 drivers/iommu/amd_iommu.c   Joerg Roedel 2011-11-10  817  static void iommu_poll_ppr_log(struct amd_iommu *iommu)
72e1dcc4192288 drivers/iommu/amd_iommu.c   Joerg Roedel 2011-11-10  818  {
72e1dcc4192288 drivers/iommu/amd_iommu.c   Joerg Roedel 2011-11-10  819  	u32 head, tail;
72e1dcc4192288 drivers/iommu/amd_iommu.c   Joerg Roedel 2011-11-10  820  
72e1dcc4192288 drivers/iommu/amd_iommu.c   Joerg Roedel 2011-11-10  821  	if (iommu->ppr_log == NULL)
72e1dcc4192288 drivers/iommu/amd_iommu.c   Joerg Roedel 2011-11-10  822  		return;
72e1dcc4192288 drivers/iommu/amd_iommu.c   Joerg Roedel 2011-11-10  823  
72e1dcc4192288 drivers/iommu/amd_iommu.c   Joerg Roedel 2011-11-10  824  	head = readl(iommu->mmio_base + MMIO_PPR_HEAD_OFFSET);
72e1dcc4192288 drivers/iommu/amd_iommu.c   Joerg Roedel 2011-11-10  825  	tail = readl(iommu->mmio_base + MMIO_PPR_TAIL_OFFSET);
72e1dcc4192288 drivers/iommu/amd_iommu.c   Joerg Roedel 2011-11-10  826  
72e1dcc4192288 drivers/iommu/amd_iommu.c   Joerg Roedel 2011-11-10  827  	while (head != tail) {
eee53537c476c9 drivers/iommu/amd_iommu.c   Joerg Roedel 2012-06-01  828  		volatile u64 *raw;
eee53537c476c9 drivers/iommu/amd_iommu.c   Joerg Roedel 2012-06-01 @829  		u64 entry[2];
eee53537c476c9 drivers/iommu/amd_iommu.c   Joerg Roedel 2012-06-01  830  		int i;
72e1dcc4192288 drivers/iommu/amd_iommu.c   Joerg Roedel 2011-11-10  831  
eee53537c476c9 drivers/iommu/amd_iommu.c   Joerg Roedel 2012-06-01  832  		raw = (u64 *)(iommu->ppr_log + head);
72e1dcc4192288 drivers/iommu/amd_iommu.c   Joerg Roedel 2011-11-10  833  
eee53537c476c9 drivers/iommu/amd_iommu.c   Joerg Roedel 2012-06-01  834  		/*
eee53537c476c9 drivers/iommu/amd_iommu.c   Joerg Roedel 2012-06-01  835  		 * Hardware bug: Interrupt may arrive before the entry is
eee53537c476c9 drivers/iommu/amd_iommu.c   Joerg Roedel 2012-06-01  836  		 * written to memory. If this happens we need to wait for the
eee53537c476c9 drivers/iommu/amd_iommu.c   Joerg Roedel 2012-06-01  837  		 * entry to arrive.
eee53537c476c9 drivers/iommu/amd_iommu.c   Joerg Roedel 2012-06-01  838  		 */
eee53537c476c9 drivers/iommu/amd_iommu.c   Joerg Roedel 2012-06-01  839  		for (i = 0; i < LOOP_TIMEOUT; ++i) {
eee53537c476c9 drivers/iommu/amd_iommu.c   Joerg Roedel 2012-06-01  840  			if (PPR_REQ_TYPE(raw[0]) != 0)
eee53537c476c9 drivers/iommu/amd_iommu.c   Joerg Roedel 2012-06-01  841  				break;
eee53537c476c9 drivers/iommu/amd_iommu.c   Joerg Roedel 2012-06-01  842  			udelay(1);
eee53537c476c9 drivers/iommu/amd_iommu.c   Joerg Roedel 2012-06-01  843  		}
eee53537c476c9 drivers/iommu/amd_iommu.c   Joerg Roedel 2012-06-01  844  
eee53537c476c9 drivers/iommu/amd_iommu.c   Joerg Roedel 2012-06-01  845  		/* Avoid memcpy function-call overhead */
eee53537c476c9 drivers/iommu/amd_iommu.c   Joerg Roedel 2012-06-01  846  		entry[0] = raw[0];
eee53537c476c9 drivers/iommu/amd_iommu.c   Joerg Roedel 2012-06-01  847  		entry[1] = raw[1];
eee53537c476c9 drivers/iommu/amd_iommu.c   Joerg Roedel 2012-06-01  848  
eee53537c476c9 drivers/iommu/amd_iommu.c   Joerg Roedel 2012-06-01  849  		/*
05d227efbd8d3c drivers/iommu/amd/iommu.c   Tom Lendacky 2023-01-17  850  		 * To detect the hardware errata 733 we need to clear the
05d227efbd8d3c drivers/iommu/amd/iommu.c   Tom Lendacky 2023-01-17  851  		 * entry back to zero. This issue does not exist on SNP
05d227efbd8d3c drivers/iommu/amd/iommu.c   Tom Lendacky 2023-01-17  852  		 * enabled system. Also this buffer is not writeable on
05d227efbd8d3c drivers/iommu/amd/iommu.c   Tom Lendacky 2023-01-17  853  		 * SNP enabled system.
eee53537c476c9 drivers/iommu/amd_iommu.c   Joerg Roedel 2012-06-01  854  		 */
05d227efbd8d3c drivers/iommu/amd/iommu.c   Tom Lendacky 2023-01-17  855  		if (!amd_iommu_snp_en)
eee53537c476c9 drivers/iommu/amd_iommu.c   Joerg Roedel 2012-06-01  856  			raw[0] = raw[1] = 0UL;
eee53537c476c9 drivers/iommu/amd_iommu.c   Joerg Roedel 2012-06-01  857  
eee53537c476c9 drivers/iommu/amd_iommu.c   Joerg Roedel 2012-06-01  858  		/* Update head pointer of hardware ring-buffer */
72e1dcc4192288 drivers/iommu/amd_iommu.c   Joerg Roedel 2011-11-10  859  		head = (head + PPR_ENTRY_SIZE) % PPR_LOG_SIZE;
72e1dcc4192288 drivers/iommu/amd_iommu.c   Joerg Roedel 2011-11-10  860  		writel(head, iommu->mmio_base + MMIO_PPR_HEAD_OFFSET);
eee53537c476c9 drivers/iommu/amd_iommu.c   Joerg Roedel 2012-06-01  861  
d55b0d2e075ad3 drivers/iommu/amd/iommu.c   Vasant Hegde 2023-10-06  862  		/* TODO: PPR Handler will be added when we add IOPF support */
eee53537c476c9 drivers/iommu/amd_iommu.c   Joerg Roedel 2012-06-01  863  
eee53537c476c9 drivers/iommu/amd_iommu.c   Joerg Roedel 2012-06-01  864  		/* Refresh ring-buffer information */
eee53537c476c9 drivers/iommu/amd_iommu.c   Joerg Roedel 2012-06-01  865  		head = readl(iommu->mmio_base + MMIO_PPR_HEAD_OFFSET);
72e1dcc4192288 drivers/iommu/amd_iommu.c   Joerg Roedel 2011-11-10  866  		tail = readl(iommu->mmio_base + MMIO_PPR_TAIL_OFFSET);
72e1dcc4192288 drivers/iommu/amd_iommu.c   Joerg Roedel 2011-11-10  867  	}
72e1dcc4192288 drivers/iommu/amd_iommu.c   Joerg Roedel 2011-11-10  868  }
72e1dcc4192288 drivers/iommu/amd_iommu.c   Joerg Roedel 2011-11-10  869  

:::::: The code at line 829 was first introduced by commit
:::::: eee53537c476c947bf7faa1c916d2f5a0ae8ec93 iommu/amd: Fix deadlock in ppr-handling error path

:::::: TO: Joerg Roedel <joerg.roedel@amd.com>
:::::: CC: Joerg Roedel <joerg.roedel@amd.com>

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

             reply	other threads:[~2023-10-07  3:20 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-10-07  3:20 kernel test robot [this message]
2023-10-12  5:26 ` [joro-iommu:x86/amd 16/19] drivers/iommu/amd/iommu.c:829:21: warning: variable 'entry' set but not used Vasant Hegde
2023-10-12 13:21   ` Jason Gunthorpe

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