Re: [PATCH v1 12/29] xen/asm-generic: introduce stub header pci.h

[Oleksii <oleksii.kurochko@xxxxxxxxx>]

Hello Jan,

On Thu, 2023-10-19 at 11:55 +0200, Jan Beulich wrote:
> On 14.09.2023 16:56, Oleksii Kurochko wrote:
> > --- /dev/null
> > +++ b/xen/include/asm-generic/pci.h
> > @@ -0,0 +1,18 @@
> > +/* SPDX-License-Identifier: GPL-2.0-only */
> > +#ifndef __ASM_GENERIC_PCI_H__
> > +#define __ASM_GENERIC_PCI_H__
> > +
> > +struct arch_pci_dev {
> > +};
> > +
> > +#endif /* __ASM_GENERIC_PCI_H__ */
> 
> While more involved, I still wonder whether xen/pci.h could also
> avoid
> including asm/pci.h when !HAS_PCI. Of course there's more than just
> the
> #include which then would need #ifdef-ing out.
> 
> Jan

It looks like we can do that but only one question should be resolved.
In ARM case, in <asm/pci.h> there is !HAS_PCI branch:

#else   /*!CONFIG_HAS_PCI*/

struct arch_pci_dev { };

static always_inline bool is_pci_passthrough_enabled(void)
{
    return false;
}

struct pci_dev;

static inline void arch_pci_init_pdev(struct pci_dev *pdev) {}

static inline int pci_get_host_bridge_segment(const struct
dt_device_node *node,
                                              uint16_t *segment)
{
    ASSERT_UNREACHABLE();
    return -EINVAL;
}

static inline int pci_get_new_domain_nr(void)
{
    ASSERT_UNREACHABLE();
    return -1;
}

#endif  /*!CONFIG_HAS_PCI*/

And if is_pci_passthrough_enabled(), arch_pci_init_pdev() is used by
all architrectures but pci_get_host_bridge_segment() and
pci_get_new_domain_nr() is ARM specific.
Does it make sense to add them to <xen/pci.h> and ifdef them?

~ Oleksii