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

From: Andrew Murray
Date: Tue Nov 13 2012 - 05:01:13 EST


Hello,

Some comments inline...

On 13 November 2012 09:07, Takao Indoh <indou.takao@xxxxxxxxxxxxxx> wrote:
> From: Yinghai Lu <yinghai@xxxxxxxxxx>
>
> So we can pass pci_dev *dev to reuse some generic pci functions.
>
> Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx>
> Signed-off-by: Takao Indoh <indou.takao@xxxxxxxxxxxxxx>
> ---
> 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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