Re: [lpieralisi-pci:pci/rcar 2/2] drivers/pci/controller/pcie-rcar-host.c:139:3: error: instruction requires: data-barriers

[Bjorn Helgaas <helgaas@kernel.org>]

On Wed, Mar 09, 2022 at 05:04:28PM +0800, kernel test robot wrote:
> tree:   https://git.kernel.org/pub/scm/linux/kernel/git/lpieralisi/pci.git pci/rcar
> head:   9775965dbae50a04f12879179d6d6fb58f240d6b
> commit: 9775965dbae50a04f12879179d6d6fb58f240d6b [2/2] PCI: rcar: Use PCI_SET_ERROR_RESPONSE after read which triggered an exception
> config: arm-randconfig-c002-20220307 (https://download.01.org/0day-ci/archive/20220309/202203091741.IetDk7a7-lkp@intel.com/config)
> compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project d271fc04d5b97b12e6b797c6067d3c96a8d7470e)
> 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 arm cross compiling tool for clang build
>         # apt-get install binutils-arm-linux-gnueabi
>         # https://git.kernel.org/pub/scm/linux/kernel/git/lpieralisi/pci.git/commit/?id=9775965dbae50a04f12879179d6d6fb58f240d6b
>         git remote add lpieralisi-pci https://git.kernel.org/pub/scm/linux/kernel/git/lpieralisi/pci.git
>         git fetch --no-tags lpieralisi-pci pci/rcar
>         git checkout 9775965dbae50a04f12879179d6d6fb58f240d6b
>         # save the config file to linux build tree
>         mkdir build_dir
>         COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=arm SHELL=/bin/bash
> 
> If you fix the issue, kindly add following tag as appropriate
> Reported-by: kernel test robot <lkp@intel.com>
> 
> All errors (new ones prefixed by >>):
> 
> >> drivers/pci/controller/pcie-rcar-host.c:139:3: error: instruction requires: data-barriers
>                    __rcar_pci_rw_reg_workaround("str")
>                    ^
>    drivers/pci/controller/pcie-rcar-host.c:120:4: note: expanded from macro '__rcar_pci_rw_reg_workaround'
>                    "2:     isb\n"                                          \
>                     ^
>    <inline asm>:2:4: note: instantiated into assembly here
>    2:      isb
>            ^
>    drivers/pci/controller/pcie-rcar-host.c:153:3: error: instruction requires: data-barriers
>                    __rcar_pci_rw_reg_workaround("ldr")
>                    ^
>    drivers/pci/controller/pcie-rcar-host.c:120:4: note: expanded from macro '__rcar_pci_rw_reg_workaround'
>                    "2:     isb\n"                                          \
>                     ^
>    <inline asm>:2:4: note: instantiated into assembly here
>    2:      isb
>            ^
>    2 errors generated.

I don't know how to fix this.  We currently have these on Lorenzo's
pci/rcar branch:

  9775965dbae5 ("PCI: rcar: Use PCI_SET_ERROR_RESPONSE after read which triggered an exception")
  de6b5097f58b ("PCI: rcar: Finish transition to L1 state in rcar_pcie_config_access()")

To avoid this error, for now I have cherry-picked de6b5097f58b to a
local pci/host/rcar branch and dropped 9775965dbae5.

> vim +139 drivers/pci/controller/pcie-rcar-host.c
> 
>    132	
>    133	static int rcar_pci_write_reg_workaround(struct rcar_pcie *pcie, u32 val,
>    134						 unsigned int reg)
>    135	{
>    136		int error = PCIBIOS_SUCCESSFUL;
>    137	#ifdef CONFIG_ARM
>    138		asm volatile(
>  > 139			__rcar_pci_rw_reg_workaround("str")
>    140		: "+r"(error):"r"(val), "r"(pcie->base + reg) : "memory");
>    141	#else
>    142		rcar_pci_write_reg(pcie, val, reg);
>    143	#endif
>    144		return error;
>    145	}
>    146	
> 
> ---
> 0-DAY CI Kernel Test Service, Intel Corporation
> https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org