[PATCH v6 1/5] x86, pci: add dummy pci device for early stage

Andrew Murray amurray at embedded-bits.co.uk
Tue Nov 13 05:01:21 EST 2012


Hello,

Some comments inline...

On 13 November 2012 09:07, Takao Indoh <indou.takao at jp.fujitsu.com> wrote:
> From: Yinghai Lu <yinghai at kernel.org>
>
> So we can pass pci_dev *dev to reuse some generic pci functions.
>
> Signed-off-by: Yinghai Lu <yinghai at kernel.org>
> Signed-off-by: Takao Indoh <indou.takao at jp.fujitsu.com>
> ---
>  arch/x86/include/asm/pci-direct.h |    2 +
>  arch/x86/pci/early.c              |   75 +++++++++++++++++++++++++++++++++++++
>  2 files changed, 77 insertions(+), 0 deletions(-)
>
> diff --git a/arch/x86/include/asm/pci-direct.h b/arch/x86/include/asm/pci-direct.h
> index b1e7a45..b6360d3 100644
> --- a/arch/x86/include/asm/pci-direct.h
> +++ b/arch/x86/include/asm/pci-direct.h
> @@ -18,4 +18,6 @@ extern int early_pci_allowed(void);
>  extern unsigned int pci_early_dump_regs;
>  extern void early_dump_pci_device(u8 bus, u8 slot, u8 func);
>  extern void early_dump_pci_devices(void);
> +
> +struct pci_dev *get_early_pci_dev(int num, int slot, int func);
>  #endif /* _ASM_X86_PCI_DIRECT_H */
> diff --git a/arch/x86/pci/early.c b/arch/x86/pci/early.c
> index d1067d5..aea6b2b 100644
> --- a/arch/x86/pci/early.c
> +++ b/arch/x86/pci/early.c
> @@ -109,3 +109,78 @@ void early_dump_pci_devices(void)
>                 }
>         }
>  }
> +
> +static __init int
> +early_pci_read(struct pci_bus *bus, unsigned int devfn, int where,
> +                       int size, u32 *value)
> +{
> +       int num, slot, func;
> +
> +       num = bus->number;
> +       slot = devfn >> 3;
> +       func = devfn & 7;

You may want to use the PCI_SLOT and PCI_FUNC macros in
include/linux/pci.h to determine values for slot and func.

> +       switch (size) {
> +       case 1:
> +               *value = read_pci_config_byte(num, slot, func, where);
> +               break;
> +       case 2:
> +               *value = read_pci_config_16(num, slot, func, where);
> +               break;
> +       case 4:
> +               *value = read_pci_config(num, slot, func, where);
> +               break;
> +       }
> +
> +       return 0;
> +}
> +
> +static __init int
> +early_pci_write(struct pci_bus *bus, unsigned int devfn, int where,
> +                       int size, u32 value)
> +{
> +       int num, slot, func;
> +
> +       num = bus->number;
> +       slot = devfn >> 3;
> +       func = devfn & 7;

As above.

> +       switch (size) {
> +       case 1:
> +               write_pci_config_byte(num, slot, func, where, (u8)value);
> +               break;
> +       case 2:
> +               write_pci_config_16(num, slot, func, where, (u16)value);
> +               break;
> +       case 4:
> +               write_pci_config(num, slot, func, where, (u32)value);
> +               break;
> +       }
> +
> +       return 0;
> +}
> +
> +static __initdata struct pci_ops pci_early_ops = {
> +       .read  = early_pci_read,
> +       .write = early_pci_write,
> +};
> +static __initdata struct pci_bus pci_early_bus = {
> +       .ops = &pci_early_ops,
> +};
> +static __initdata char pci_early_init_name[8];
> +static __initdata struct pci_dev pci_early_dev = {
> +       .bus = &pci_early_bus,
> +       .dev = {
> +               .init_name = pci_early_init_name,
> +       },
> +};
> +
> +__init struct pci_dev *get_early_pci_dev(int num, int slot, int func)
> +{
> +       struct pci_dev *pdev;
> +
> +       pdev = &pci_early_dev;
> +       pdev->devfn = (slot<<3) | (func & 7);

You can use PCI_DEVFN here.

> +       pdev->bus->number = num;
> +       sprintf((char *)pdev->dev.init_name, "%02x:%02x.%01x", num, slot, func);
> +
> +       return pdev;
> +}
> --
> 1.7.1
>
>
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Andrew Murray



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