Re: [PATCH v3 5/6] PCI: cadence: Add callback functions for RP and EP controller

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

Hi,

kernel test robot noticed the following build warnings:

[auto build test WARNING on a24588245776dafc227243a01bfbeb8a59bafba9]

url:    https://github.com/intel-lab-lkp/linux/commits/hans-zhang-cixtech-com/dt-bindings-pci-cadence-Extend-compatible-for-new-RP-configuration/20250414-094836
base:   a24588245776dafc227243a01bfbeb8a59bafba9
patch link:    https://lore.kernel.org/r/20250411103656.2740517-6-hans.zhang%40cixtech.com
patch subject: [PATCH v3 5/6] PCI: cadence: Add callback functions for RP and EP controller
config: powerpc64-randconfig-001-20250414 (https://download.01.org/0day-ci/archive/20250414/202504141719.svx3rf5x-lkp@intel.com/config)
compiler: clang version 17.0.6 (https://github.com/llvm/llvm-project 6009708b4367171ccdbf4b5905cb6a803753fe18)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250414/202504141719.svx3rf5x-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/202504141719.svx3rf5x-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> drivers/pci/controller/cadence/pcie-cadence.c:303:12: warning: variable 'ctrl0' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized]
     303 |                 desc1 |= CDNS_PCIE_HPA_AT_OB_REGION_DESC1_DEVFN(fn);
         |                          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   drivers/pci/controller/cadence/pcie-cadence.h:342:2: note: expanded from macro 'CDNS_PCIE_HPA_AT_OB_REGION_DESC1_DEVFN'
     342 |         FIELD_PREP(CDNS_PCIE_HPA_AT_OB_REGION_DESC1_DEVFN_MASK, devfn)
         |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   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:68:3: note: expanded from macro '__BF_FIELD_CHECK'
      68 |                 BUILD_BUG_ON_MSG(__builtin_constant_p(_val) ?           \
         |                 ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
      69 |                                  ~((_mask) >> __bf_shf(_mask)) &        \
         |                                  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
      70 |                                         (0 + (_val)) : 0,               \
         |                                         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
      71 |                                  _pfx "value too large for the field"); \
         |                                  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   note: (skipping 1 expansions in backtrace; use -fmacro-backtrace-limit=0 to see all)
   include/linux/compiler_types.h:557:2: note: expanded from macro 'compiletime_assert'
     557 |         _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
         |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/compiler_types.h:545:2: note: expanded from macro '_compiletime_assert'
     545 |         __compiletime_assert(condition, msg, prefix, suffix)
         |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/compiler_types.h:537:7: note: expanded from macro '__compiletime_assert'
     537 |                 if (!(condition))                                       \
         |                     ^~~~~~~~~~~~
   drivers/pci/controller/cadence/pcie-cadence.c:323:46: note: uninitialized use occurs here
     323 |                              CDNS_PCIE_HPA_AT_OB_REGION_CTRL0(r), ctrl0);
         |                                                                   ^~~~~
   drivers/pci/controller/cadence/pcie-cadence.c:303:12: note: remove the 'if' if its condition is always true
     303 |                 desc1 |= CDNS_PCIE_HPA_AT_OB_REGION_DESC1_DEVFN(fn);
         |                          ^
   drivers/pci/controller/cadence/pcie-cadence.h:342:2: note: expanded from macro 'CDNS_PCIE_HPA_AT_OB_REGION_DESC1_DEVFN'
     342 |         FIELD_PREP(CDNS_PCIE_HPA_AT_OB_REGION_DESC1_DEVFN_MASK, devfn)
         |         ^
   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:68:3: note: expanded from macro '__BF_FIELD_CHECK'
      68 |                 BUILD_BUG_ON_MSG(__builtin_constant_p(_val) ?           \
         |                 ^
   note: (skipping 1 expansions in backtrace; use -fmacro-backtrace-limit=0 to see all)
   include/linux/compiler_types.h:557:2: note: expanded from macro 'compiletime_assert'
     557 |         _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
         |         ^
   include/linux/compiler_types.h:545:2: note: expanded from macro '_compiletime_assert'
     545 |         __compiletime_assert(condition, msg, prefix, suffix)
         |         ^
   include/linux/compiler_types.h:537:3: note: expanded from macro '__compiletime_assert'
     537 |                 if (!(condition))                                       \
         |                 ^
   drivers/pci/controller/cadence/pcie-cadence.c:291:39: note: initialize the variable 'ctrl0' to silence this warning
     291 |         u32 addr0, addr1, desc0, desc1, ctrl0;
         |                                              ^
         |                                               = 0
   1 warning generated.
--
>> drivers/pci/controller/cadence/pcie-cadence-host.c:122:3: warning: variable 'desc0' is uninitialized when used here [-Wuninitialized]
     122 |                 desc0 |= CDNS_PCIE_HPA_AT_OB_REGION_DESC0_TYPE_CONF_TYPE0;
         |                 ^~~~~
   drivers/pci/controller/cadence/pcie-cadence-host.c:80:18: note: initialize the variable 'desc0' to silence this warning
      80 |         u32 addr0, desc0, desc1, ctrl0;
         |                         ^
         |                          = 0
   1 warning generated.


vim +303 drivers/pci/controller/cadence/pcie-cadence.c

   286	
   287	void cdns_pcie_hpa_set_outbound_region_for_normal_msg(struct cdns_pcie *pcie,
   288							      u8 busnr, u8 fn,
   289							      u32 r, u64 cpu_addr)
   290	{
   291		u32 addr0, addr1, desc0, desc1, ctrl0;
   292	
   293		desc0 = CDNS_PCIE_HPA_AT_OB_REGION_DESC0_TYPE_NORMAL_MSG;
   294		desc1 = 0;
   295	
   296		/* See cdns_pcie_set_outbound_region() comments above. */
   297		if (pcie->is_rc) {
   298			desc1 = CDNS_PCIE_HPA_AT_OB_REGION_DESC1_BUS(busnr) |
   299				CDNS_PCIE_HPA_AT_OB_REGION_DESC1_DEVFN(0);
   300			ctrl0 = CDNS_PCIE_HPA_AT_OB_REGION_CTRL0_SUPPLY_BUS |
   301				CDNS_PCIE_HPA_AT_OB_REGION_CTRL0_SUPPLY_DEV_FN;
   302		} else {
 > 303			desc1 |= CDNS_PCIE_HPA_AT_OB_REGION_DESC1_DEVFN(fn);
   304		}
   305	
   306		addr0 = CDNS_PCIE_HPA_AT_OB_REGION_CPU_ADDR0_NBITS(17) |
   307			(lower_32_bits(cpu_addr) & GENMASK(31, 8));
   308		addr1 = upper_32_bits(cpu_addr);
   309	
   310		cdns_pcie_hpa_writel(pcie, REG_BANK_AXI_SLAVE,
   311				     CDNS_PCIE_HPA_AT_OB_REGION_PCI_ADDR0(r), 0);
   312		cdns_pcie_hpa_writel(pcie, REG_BANK_AXI_SLAVE,
   313				     CDNS_PCIE_HPA_AT_OB_REGION_PCI_ADDR1(r), 0);
   314		cdns_pcie_hpa_writel(pcie, REG_BANK_AXI_SLAVE,
   315				     CDNS_PCIE_HPA_AT_OB_REGION_DESC0(r), desc0);
   316		cdns_pcie_hpa_writel(pcie, REG_BANK_AXI_SLAVE,
   317				     CDNS_PCIE_HPA_AT_OB_REGION_DESC1(r), desc1);
   318		cdns_pcie_hpa_writel(pcie, REG_BANK_AXI_SLAVE,
   319				     CDNS_PCIE_HPA_AT_OB_REGION_CPU_ADDR0(r), addr0);
   320		cdns_pcie_hpa_writel(pcie, REG_BANK_AXI_SLAVE,
   321				     CDNS_PCIE_HPA_AT_OB_REGION_CPU_ADDR1(r), addr1);
   322		cdns_pcie_hpa_writel(pcie, REG_BANK_AXI_SLAVE,
   323				     CDNS_PCIE_HPA_AT_OB_REGION_CTRL0(r), ctrl0);
   324	}
   325	

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