Re: [PATCH V6 2/5] PCI/TPH: Add Steering Tag support

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

Hi Wei,

kernel test robot noticed the following build warnings:

[auto build test WARNING on pci/next]
[also build test WARNING on pci/for-linus linus/master next-20240927]
[cannot apply to v6.11]
[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/Wei-Huang/PCI-Add-TLP-Processing-Hints-TPH-support/20240928-055915
base:   https://git.kernel.org/pub/scm/linux/kernel/git/pci/pci.git next
patch link:    https://lore.kernel.org/r/20240927215653.1552411-3-wei.huang2%40amd.com
patch subject: [PATCH V6 2/5] PCI/TPH: Add Steering Tag support
config: x86_64-allyesconfig (https://download.01.org/0day-ci/archive/20240928/202409282017.PWd5zICd-lkp@intel.com/config)
compiler: clang version 18.1.8 (https://github.com/llvm/llvm-project 3b5b5c1ec4a3095ab096dd780e84d7ab81f3d7ff)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240928/202409282017.PWd5zICd-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/202409282017.PWd5zICd-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> drivers/pci/tph.c:236:9: warning: result of comparison of constant 18446744073709551615 with expression of type 'typeof (_Generic((mask), char: (unsigned char)0, unsigned char: (unsigned char)0, signed char: (unsigned char)0, unsigned short: (unsigned short)0, short: (unsigned short)0, unsigned int: (unsigned int)0, int: (unsigned int)0, unsigned long: (unsigned long)0, long: (unsigned long)0, unsigned long long: (unsigned long long)0, long long: (unsigned long long)0, default: (mask)))' (aka 'unsigned int') is always false [-Wtautological-constant-out-of-range-compare]
     236 |         val |= FIELD_PREP(mask, st_val);
         |                ^~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/bitfield.h:115:3: note: expanded from macro 'FIELD_PREP'
     115 |                 __BF_FIELD_CHECK(_mask, 0ULL, _val, "FIELD_PREP: ");    \
         |                 ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/bitfield.h:72:53: note: expanded from macro '__BF_FIELD_CHECK'
      72 |                 BUILD_BUG_ON_MSG(__bf_cast_unsigned(_mask, _mask) >     \
         |                 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~
      73 |                                  __bf_cast_unsigned(_reg, ~0ull),       \
         |                                  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
      74 |                                  _pfx "type of reg too small for mask"); \
         |                                  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/build_bug.h:39:58: note: expanded from macro 'BUILD_BUG_ON_MSG'
      39 | #define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg)
         |                                     ~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~
   include/linux/compiler_types.h:517:22: note: expanded from macro 'compiletime_assert'
     517 |         _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
         |         ~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/compiler_types.h:505:23: note: expanded from macro '_compiletime_assert'
     505 |         __compiletime_assert(condition, msg, prefix, suffix)
         |         ~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/compiler_types.h:497:9: note: expanded from macro '__compiletime_assert'
     497 |                 if (!(condition))                                       \
         |                       ^~~~~~~~~
   1 warning generated.


vim +236 drivers/pci/tph.c

   205	
   206	/* Write ST to MSI-X vector control reg - Return 0 if OK, otherwise -errno */
   207	static int write_tag_to_msix(struct pci_dev *pdev, int msix_idx, u16 tag)
   208	{
   209		struct msi_desc *msi_desc = NULL;
   210		void __iomem *vec_ctrl;
   211		u32 val, mask, st_val;
   212		int err = 0;
   213	
   214		msi_lock_descs(&pdev->dev);
   215	
   216		/* Find the msi_desc entry with matching msix_idx */
   217		msi_for_each_desc(msi_desc, &pdev->dev, MSI_DESC_ASSOCIATED) {
   218			if (msi_desc->msi_index == msix_idx)
   219				break;
   220		}
   221	
   222		if (!msi_desc) {
   223			err = -ENXIO;
   224			goto err_out;
   225		}
   226	
   227		st_val = (u32)tag;
   228	
   229		/* Get the vector control register (offset 0xc) pointed by msix_idx */
   230		vec_ctrl = pdev->msix_base + msix_idx * PCI_MSIX_ENTRY_SIZE;
   231		vec_ctrl += PCI_MSIX_ENTRY_VECTOR_CTRL;
   232	
   233		val = readl(vec_ctrl);
   234		mask = PCI_MSIX_ENTRY_CTRL_ST_LOWER | PCI_MSIX_ENTRY_CTRL_ST_UPPER;
   235		val &= ~mask;
 > 236		val |= FIELD_PREP(mask, st_val);
   237		writel(val, vec_ctrl);
   238	
   239		/* Read back to flush the update */
   240		val = readl(vec_ctrl);
   241	
   242	err_out:
   243		msi_unlock_descs(&pdev->dev);
   244		return err;
   245	}
   246	

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