Re: [PATCH v3 5/6] MIPS: implement architecture-specific 'pci_remap_iospace()'

Xi Ruoyao
2021-12-16T11:52:58Z

On Sat, 2021-09-25 at 22:32 +0200, Sergio Paracuellos wrote:
> To make PCI IO work we need to properly virtually map IO cpu physical address
> and set this virtual address as the address of the first PCI IO port which
> is set using function 'set_io_port_base()'.
>
> Acked-by: Arnd Bergmann <arnd@arndb.de>
> Signed-off-by: Sergio Paracuellos <sergio.paracuellos@gmail.com>

Hi,

the change is causing a WARNING on loongson64g-4core-ls7a:

[ 0.105781] loongson-pci 1a000000.pci: IO 0x0018020000..0x001803ffff ->
0x0000020000
[ 0.105792] loongson-pci 1a000000.pci: MEM 0x0040000000..0x007fffffff ->
0x0040000000
[ 0.105801] ------------[ cut here ]------------
[ 0.105804] WARNING: CPU: 0 PID: 1 at arch/mips/pci/pci-generic.c:55 pci_remap_iospace+0x80/0x88
[ 0.105815] resource start address is not zero

I'm not sure how to fix this one.

> ---
>  arch/mips/include/asm/pci.h |  2 ++
>  arch/mips/pci/pci-generic.c | 14 ++++++++++++++
>  2 files changed, 16 insertions(+)
>
> diff --git a/arch/mips/include/asm/pci.h b/arch/mips/include/asm/pci.h
> index 9ffc8192adae..35270984a5f0 100644
> --- a/arch/mips/include/asm/pci.h
> +++ b/arch/mips/include/asm/pci.h
> @@ -20,6 +20,8 @@
>  #include <linux/list.h>
>  #include <linux/of.h>
>
> +#define pci_remap_iospace pci_remap_iospace
> +
>  #ifdef CONFIG_PCI_DRIVERS_LEGACY
>
>  /*
> diff --git a/arch/mips/pci/pci-generic.c b/arch/mips/pci/pci-generic.c
> index 95b00017886c..18eb8a453a86 100644
> --- a/arch/mips/pci/pci-generic.c
> +++ b/arch/mips/pci/pci-generic.c
> @@ -46,3 +46,17 @@ void pcibios_fixup_bus(struct pci_bus *bus)
>  {
>         pci_read_bridge_bases(bus);
>  }
> +
> +int pci_remap_iospace(const struct resource *res, phys_addr_t phys_addr)
> +{
> +       unsigned long vaddr;
> +
> +       if (res->start != 0) {
> +               WARN_ONCE(1, "resource start address is not zero\n");
> +               return -ENODEV;
> +       }
> +
> +       vaddr = (unsigned long)ioremap(phys_addr, resource_size(res));
> +       set_io_port_base(vaddr);
> +       return 0;
> +}

--
Xi Ruoyao <xry111@mengyan1223.wang>
School of Aerospace Science and Technology, Xidian University