Re: [PATCH v3 04/15] PCI: Add pci_find_vsec_capability() to find a specific VSEC

From: kernel test robot
Date: Wed Feb 03 2021 - 16:12:40 EST


Hi Gustavo,

I love your patch! Perhaps something to improve:

[auto build test WARNING on vkoul-dmaengine/next]
[also build test WARNING on pci/next linux/master linus/master v5.11-rc6 next-20210125]
[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]

url: https://github.com/0day-ci/linux/commits/Gustavo-Pimentel/dmaengine-dw-edma-HDMA-support/20210204-021120
base: https://git.kernel.org/pub/scm/linux/kernel/git/vkoul/dmaengine.git next
config: s390-randconfig-r031-20210202 (attached as .config)
compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project 275c6af7d7f1ed63a03d05b4484413e447133269)
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# install s390 cross compiling tool for clang build
# apt-get install binutils-s390x-linux-gnu
# https://github.com/0day-ci/linux/commit/01913af21093b2ba821ea6ff4846edff4971e981
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review Gustavo-Pimentel/dmaengine-dw-edma-HDMA-support/20210204-021120
git checkout 01913af21093b2ba821ea6ff4846edff4971e981
# save the attached .config to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=s390

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@xxxxxxxxx>

All warnings (new ones prefixed by >>):

#define __le32_to_cpu(x) __swab32((__force __u32)(__le32)(x))
^
include/uapi/linux/swab.h:119:21: note: expanded from macro '__swab32'
___constant_swab32(x) : \
^
include/uapi/linux/swab.h:19:12: note: expanded from macro '___constant_swab32'
(((__u32)(x) & (__u32)0x000000ffUL) << 24) | \
^
In file included from drivers/pci/pci.c:18:
In file included from include/linux/pci.h:39:
In file included from include/linux/io.h:13:
In file included from arch/s390/include/asm/io.h:80:
include/asm-generic/io.h:490:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
val = __le32_to_cpu((__le32 __force)__raw_readl(PCI_IOBASE + addr));
~~~~~~~~~~ ^
include/uapi/linux/byteorder/big_endian.h:34:59: note: expanded from macro '__le32_to_cpu'
#define __le32_to_cpu(x) __swab32((__force __u32)(__le32)(x))
^
include/uapi/linux/swab.h:119:21: note: expanded from macro '__swab32'
___constant_swab32(x) : \
^
include/uapi/linux/swab.h:20:12: note: expanded from macro '___constant_swab32'
(((__u32)(x) & (__u32)0x0000ff00UL) << 8) | \
^
In file included from drivers/pci/pci.c:18:
In file included from include/linux/pci.h:39:
In file included from include/linux/io.h:13:
In file included from arch/s390/include/asm/io.h:80:
include/asm-generic/io.h:490:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
val = __le32_to_cpu((__le32 __force)__raw_readl(PCI_IOBASE + addr));
~~~~~~~~~~ ^
include/uapi/linux/byteorder/big_endian.h:34:59: note: expanded from macro '__le32_to_cpu'
#define __le32_to_cpu(x) __swab32((__force __u32)(__le32)(x))
^
include/uapi/linux/swab.h:119:21: note: expanded from macro '__swab32'
___constant_swab32(x) : \
^
include/uapi/linux/swab.h:21:12: note: expanded from macro '___constant_swab32'
(((__u32)(x) & (__u32)0x00ff0000UL) >> 8) | \
^
In file included from drivers/pci/pci.c:18:
In file included from include/linux/pci.h:39:
In file included from include/linux/io.h:13:
In file included from arch/s390/include/asm/io.h:80:
include/asm-generic/io.h:490:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
val = __le32_to_cpu((__le32 __force)__raw_readl(PCI_IOBASE + addr));
~~~~~~~~~~ ^
include/uapi/linux/byteorder/big_endian.h:34:59: note: expanded from macro '__le32_to_cpu'
#define __le32_to_cpu(x) __swab32((__force __u32)(__le32)(x))
^
include/uapi/linux/swab.h:119:21: note: expanded from macro '__swab32'
___constant_swab32(x) : \
^
include/uapi/linux/swab.h:22:12: note: expanded from macro '___constant_swab32'
(((__u32)(x) & (__u32)0xff000000UL) >> 24)))
^
In file included from drivers/pci/pci.c:18:
In file included from include/linux/pci.h:39:
In file included from include/linux/io.h:13:
In file included from arch/s390/include/asm/io.h:80:
include/asm-generic/io.h:490:61: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
val = __le32_to_cpu((__le32 __force)__raw_readl(PCI_IOBASE + addr));
~~~~~~~~~~ ^
include/uapi/linux/byteorder/big_endian.h:34:59: note: expanded from macro '__le32_to_cpu'
#define __le32_to_cpu(x) __swab32((__force __u32)(__le32)(x))
^
include/uapi/linux/swab.h:120:12: note: expanded from macro '__swab32'
__fswab32(x))
^
In file included from drivers/pci/pci.c:18:
In file included from include/linux/pci.h:39:
In file included from include/linux/io.h:13:
In file included from arch/s390/include/asm/io.h:80:
include/asm-generic/io.h:501:33: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
__raw_writeb(value, PCI_IOBASE + addr);
~~~~~~~~~~ ^
include/asm-generic/io.h:511:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
__raw_writew((u16 __force)cpu_to_le16(value), PCI_IOBASE + addr);
~~~~~~~~~~ ^
include/asm-generic/io.h:521:59: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
__raw_writel((u32 __force)cpu_to_le32(value), PCI_IOBASE + addr);
~~~~~~~~~~ ^
include/asm-generic/io.h:609:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
readsb(PCI_IOBASE + addr, buffer, count);
~~~~~~~~~~ ^
include/asm-generic/io.h:617:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
readsw(PCI_IOBASE + addr, buffer, count);
~~~~~~~~~~ ^
include/asm-generic/io.h:625:20: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
readsl(PCI_IOBASE + addr, buffer, count);
~~~~~~~~~~ ^
include/asm-generic/io.h:634:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
writesb(PCI_IOBASE + addr, buffer, count);
~~~~~~~~~~ ^
include/asm-generic/io.h:643:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
writesw(PCI_IOBASE + addr, buffer, count);
~~~~~~~~~~ ^
include/asm-generic/io.h:652:21: warning: performing pointer arithmetic on a null pointer has undefined behavior [-Wnull-pointer-arithmetic]
writesl(PCI_IOBASE + addr, buffer, count);
~~~~~~~~~~ ^
>> drivers/pci/pci.c:717:15: warning: equality comparison with extraneous parentheses [-Wparentheses-equality]
while ((vsec == pci_find_next_ext_capability(dev, vsec,
~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/pci/pci.c:717:15: note: remove extraneous parentheses around the comparison to silence this warning
while ((vsec == pci_find_next_ext_capability(dev, vsec,
~ ^
drivers/pci/pci.c:717:15: note: use '=' to turn this equality comparison into an assignment
while ((vsec == pci_find_next_ext_capability(dev, vsec,
^~
=
21 warnings generated.


vim +717 drivers/pci/pci.c

694
695 /**
696 * pci_find_vsec_capability - Find a vendor-specific extended capability
697 * @dev: PCI device to query
698 * @cap: vendor-specific capability ID code
699 *
700 * Typically this function will be called by the pci driver, which passes
701 * through argument the 'struct pci_dev *' already pointing for the device
702 * config space that is associated with the vendor and device ID which will
703 * know which ID to search and what to do with it, however, it might be
704 * cases that this function could be called outside of this scope and
705 * therefore is the caller responsibility to check the vendor and/or
706 * device ID first.
707 *
708 * Returns the address of the vendor-specific structure that matches the
709 * requested capability ID code within the device's PCI configuration space
710 * or 0 if it does not find a match.
711 */
712 u16 pci_find_vsec_capability(struct pci_dev *dev, int vsec_cap_id)
713 {
714 u16 vsec = 0;
715 u32 header;
716
> 717 while ((vsec == pci_find_next_ext_capability(dev, vsec,
718 PCI_EXT_CAP_ID_VNDR))) {
719 if (pci_read_config_dword(dev, vsec + PCI_VSEC_HDR,
720 &header) == PCIBIOS_SUCCESSFUL &&
721 PCI_VSEC_CAP_ID(header) == vsec_cap_id)
722 return vsec;
723 }
724
725 return 0;
726 }
727 EXPORT_SYMBOL_GPL(pci_find_vsec_capability);
728

---
0-DAY CI Kernel Test Service, Intel Corporation
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