Re: [PATCH v2 02/17] xen/pci: solve compilation error on ARM with HAS_PCI enabled

[Stefano Stabellini <sstabellini@xxxxxxxxxx>]

On Wed, 22 Sep 2021, Rahul Singh wrote:
> Compilation error is observed when HAS_PCI is enabled for ARM
> architecture.
> 
> Add definition for arch_iommu_use_permitted() and
> arch_pci_clean_pirqs().
> 
> pci.c: In function ‘deassign_device’:
> pci.c:849:49: error: implicit declaration of function ‘pci_to_dev’;
> did you mean ‘dt_to_dev’? [-Werror=implicit-function-declaration]
>             pci_to_dev(pdev));
> pci.c:880: undefined reference to `arch_pci_clean_pirqs’
> pci.c:1392: undefined reference to `arch_iommu_use_permitted'
> 
> Signed-off-by: Rahul Singh <rahul.singh@xxxxxxx>

Reviewed-by: Stefano Stabellini <sstabellini@xxxxxxxxxx>


> ---
> Change in v2:
> - Remove pci_conf_read*(..) dummy implementation
> - Add in code comment for arch_pci_clean_pirqs() and 
> arch_iommu_use_permitted()
> - Fixed minor comments
> ---
>  xen/arch/arm/Makefile               |  1 +
>  xen/arch/arm/pci/Makefile           |  1 +
>  xen/arch/arm/pci/pci.c              | 33 +++++++++++++++++++++++++++++
>  xen/drivers/passthrough/arm/iommu.c |  9 ++++++++
>  xen/include/asm-arm/pci.h           | 31 ++++++++++++++++++++++++---
>  5 files changed, 72 insertions(+), 3 deletions(-)
>  create mode 100644 xen/arch/arm/pci/Makefile
>  create mode 100644 xen/arch/arm/pci/pci.c
> 
> diff --git a/xen/arch/arm/Makefile b/xen/arch/arm/Makefile
> index 3d3b97b5b4..44d7cc81fa 100644
> --- a/xen/arch/arm/Makefile
> +++ b/xen/arch/arm/Makefile
> @@ -2,6 +2,7 @@ obj-$(CONFIG_ARM_32) += arm32/
>  obj-$(CONFIG_ARM_64) += arm64/
>  obj-$(CONFIG_ARM_64) += efi/
>  obj-$(CONFIG_ACPI) += acpi/
> +obj-$(CONFIG_HAS_PCI) += pci/
>  ifneq ($(CONFIG_NO_PLAT),y)
>  obj-y += platforms/
>  endif
> diff --git a/xen/arch/arm/pci/Makefile b/xen/arch/arm/pci/Makefile
> new file mode 100644
> index 0000000000..a98035df4c
> --- /dev/null
> +++ b/xen/arch/arm/pci/Makefile
> @@ -0,0 +1 @@
> +obj-y += pci.o
> diff --git a/xen/arch/arm/pci/pci.c b/xen/arch/arm/pci/pci.c
> new file mode 100644
> index 0000000000..a7a7bc3213
> --- /dev/null
> +++ b/xen/arch/arm/pci/pci.c
> @@ -0,0 +1,33 @@
> +/*
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program.  If not, see <http://www.gnu.org/licenses/>.
> + */
> +
> +#include <xen/pci.h>
> +
> +/*
> + * PIRQ event channels are not supported on Arm, so nothing to do.
> + */
> +int arch_pci_clean_pirqs(struct domain *d)
> +{
> +    return 0;
> +}
> +
> +/*
> + * Local variables:
> + * mode: C
> + * c-file-style: "BSD"
> + * c-basic-offset: 4
> + * tab-width: 4
> + * indent-tabs-mode: nil
> + * End:
> + */
> diff --git a/xen/drivers/passthrough/arm/iommu.c 
> b/xen/drivers/passthrough/arm/iommu.c
> index db3b07a571..ee653a9c48 100644
> --- a/xen/drivers/passthrough/arm/iommu.c
> +++ b/xen/drivers/passthrough/arm/iommu.c
> @@ -135,3 +135,12 @@ void arch_iommu_domain_destroy(struct domain *d)
>  void __hwdom_init arch_iommu_hwdom_init(struct domain *d)
>  {
>  }
> +
> +/*
> + * Unlike x86, Arm doesn't support mem-sharing, mem-paging and log-dirty 
> (yet).
> + * So there is no restriction to use the IOMMU.
> + */
> +bool arch_iommu_use_permitted(const struct domain *d)
> +{
> +    return true;
> +}
> diff --git a/xen/include/asm-arm/pci.h b/xen/include/asm-arm/pci.h
> index de13359f65..7dd9eb3dba 100644
> --- a/xen/include/asm-arm/pci.h
> +++ b/xen/include/asm-arm/pci.h
> @@ -1,7 +1,32 @@
> -#ifndef __X86_PCI_H__
> -#define __X86_PCI_H__
> +/*
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program.  If not, see <http://www.gnu.org/licenses/>.
> + */
>  
> +#ifndef __ARM_PCI_H__
> +#define __ARM_PCI_H__
> +
> +#ifdef CONFIG_HAS_PCI
> +
> +#define pci_to_dev(pcidev) (&(pcidev)->arch.dev)
> +
> +/* Arch pci dev struct */
>  struct arch_pci_dev {
> +    struct device dev;
>  };
>  
> -#endif /* __X86_PCI_H__ */
> +#else   /*!CONFIG_HAS_PCI*/
> +
> +struct arch_pci_dev { };
> +
> +#endif  /*!CONFIG_HAS_PCI*/
> +#endif /* __ARM_PCI_H__ */
> -- 
> 2.17.1
>