RE: [PATCH RESEND 1/3] PCI: Add fwnode_handle to pci_sysdata

Jake Oshins
2016-02-03T18:32:26Z

> -----Original Message-----
> From: Bjorn Helgaas [mailto:helgaas@kernel.org]
> Sent: Wednesday, February 3, 2016 10:25 AM
> To: Jake Oshins <jakeo@microsoft.com>
> Cc: gregkh@linuxfoundation.org; KY Srinivasan <kys@microsoft.com>; linux-
> kernel@vger.kernel.org; devel@linuxdriverproject.org; Haiyang Zhang
> <haiyangz@microsoft.com>; marc.zyngier@arm.com;
> bhelgaas@google.com; linux-pci@vger.kernel.org
> Subject: Re: [PATCH RESEND 1/3] PCI: Add fwnode_handle to pci_sysdata
>
> Hi Jake,
>
> On Tue, Feb 02, 2016 at 05:41:41PM +0000, jakeo@microsoft.com wrote:
> > From: Jake Oshins <jakeo@microsoft.com>
> >
> > This patch adds an fwnode_handle to struct pci_sysdata, which is used
> > by the next patch in the series when trying to locate an IRQ domain
> > associated with a root PCI bus.
> >
> > Signed-off-by: Jake Oshins <jakeo@microsoft.com>
> > ---
> > arch/x86/include/asm/pci.h | 15 +++++++++++++++
> > drivers/pci/probe.c | 1 +
> > include/linux/pci.h | 4 ++++
> > 3 files changed, 20 insertions(+)
> >
> > diff --git a/arch/x86/include/asm/pci.h b/arch/x86/include/asm/pci.h
> > index 4625943..6fc3c7c 100644
> > --- a/arch/x86/include/asm/pci.h
> > +++ b/arch/x86/include/asm/pci.h
> > @@ -20,6 +20,9 @@ struct pci_sysdata { #ifdef CONFIG_X86_64
> > void *iommu; /* IOMMU private data */
> > #endif
> > +#ifdef CONFIG_PCI_MSI_IRQ_DOMAIN
> > + void *fwnode; /* IRQ domain for MSI assignment */
> > +#endif
> > };
> >
> > extern int pci_routeirq;
> > @@ -32,6 +35,7 @@ extern int noioapicreroute; static inline int
> > pci_domain_nr(struct pci_bus *bus) {
> > struct pci_sysdata *sd = bus->sysdata;
> > +
> > return sd->domain;
> > }
> >
> > @@ -41,6 +45,17 @@ static inline int pci_proc_domain(struct pci_bus
> > *bus) } #endif
> >
> > +#ifdef CONFIG_PCI_MSI_IRQ_DOMAIN
> > +static inline void *_pci_root_bus_fwnode(struct pci_bus *bus) {
> > + struct pci_sysdata *sd = bus->sysdata;
> > +
> > + return sd->fwnode;
> > +}
> > +
> > +#define pci_root_bus_fwnode _pci_root_bus_fwnode
> > +#endif
> > +
> > /* Can be used to override the logic in pci_scan_bus for skipping
> > already-configured bus numbers - to be used for buggy BIOSes
> > or architectures with incomplete PCI setup by the loader */ diff
> > --git a/drivers/pci/probe.c b/drivers/pci/probe.c index
> > 6d7ab9b..b207e74 100644
> > --- a/drivers/pci/probe.c
> > +++ b/drivers/pci/probe.c
> > @@ -15,6 +15,7 @@
> > #include <linux/pci-aspm.h>
> > #include <linux/aer.h>
> > #include <linux/acpi.h>
> > +#include <linux/irqdomain.h>
>
> You're not adding a use of anything in irqdomain.h. It looks like this hunk
> should be moved to the second patch.

Wil do.

>
> > #include <asm-generic/pci-bridge.h>
> > #include "pci.h"
> >
> > diff --git a/include/linux/pci.h b/include/linux/pci.h index
> > 27df4a6..cd05a8e 100644
> > --- a/include/linux/pci.h
> > +++ b/include/linux/pci.h
> > @@ -1515,6 +1515,10 @@ static inline int pci_get_new_domain_nr(void) {
> > return -ENOSYS; }
> >
> > #include <asm/pci.h>
> >
> > +#ifndef pci_root_bus_fwnode
> > +#define pci_root_bus_fwnode(bus) ((void)(bus), NULL)
>
> Huh, interesting. This is new for me; I guess the idea is that we at least
> evaluate "bus" even when pci_root_bus_fwnode isn't defined, so the
> compiler can catch egregious errors?
>

This was a suggestion by Mark Zyngier. It made the non-x86 architectures build benignly. If you'd like it done differently, I'm open to suggestion.

Thanks,
Jake Oshins