| Message ID | 20210720134429.511541-2-boqun.feng@gmail.com |
|---|---|
| State | New |
| Headers | show |
| Series | PCI: hv: Support host bridge probing on ARM64 | expand |
On Tue, Jul 20, 2021 at 09:44:22PM +0800, Boqun Feng wrote: > Currently we retrieve the PCI domain number of the host bridge from the > bus sysdata (or pci_config_window if PCI_DOMAINS_GENERIC=y). Actually > we have the information at PCI host bridge probing time, and it makes > sense that we store it into pci_host_bridge. One benefit of doing so is > the requirement for supporting PCI on Hyper-V for ARM64, because the > host bridge of Hyper-V doesn't have pci_config_window, whereas ARM64 is > a PCI_DOMAINS_GENERIC=y arch, so we cannot retrieve the PCI domain > number from pci_config_window on ARM64 Hyper-V guest. > > As the preparation for ARM64 Hyper-V PCI support, we introduce the > domain_nr in pci_host_bridge and a sentinel value to allow drivers to > set domain numbers properly at probing time. Currently > CONFIG_PCI_DOMAINS_GENERIC=y archs are only users of this > newly-introduced field. > > Signed-off-by: Boqun Feng <boqun.feng@gmail.com> Once all the issues are ironed out, Lorenzo should probably merge this since it's primarily Hyper-V stuff, but I'm OK with this part: Acked-by: Bjorn Helgaas <bhelgaas@google.com> But fix the comment issue below. > --- > drivers/pci/probe.c | 6 +++++- > include/linux/pci.h | 10 ++++++++++ > 2 files changed, 15 insertions(+), 1 deletion(-) > > diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c > index 79177ac37880..60c50d4f156f 100644 > --- a/drivers/pci/probe.c > +++ b/drivers/pci/probe.c > @@ -594,6 +594,7 @@ static void pci_init_host_bridge(struct pci_host_bridge *bridge) > bridge->native_pme = 1; > bridge->native_ltr = 1; > bridge->native_dpc = 1; > + bridge->domain_nr = PCI_DOMAIN_NR_NOT_SET; > > device_initialize(&bridge->dev); > } > @@ -898,7 +899,10 @@ static int pci_register_host_bridge(struct pci_host_bridge *bridge) > bus->ops = bridge->ops; > bus->number = bus->busn_res.start = bridge->busnr; > #ifdef CONFIG_PCI_DOMAINS_GENERIC > - bus->domain_nr = pci_bus_find_domain_nr(bus, parent); > + if (bridge->domain_nr == PCI_DOMAIN_NR_NOT_SET) > + bus->domain_nr = pci_bus_find_domain_nr(bus, parent); > + else > + bus->domain_nr = bridge->domain_nr; > #endif > > b = pci_find_bus(pci_domain_nr(bus), bridge->busnr); > diff --git a/include/linux/pci.h b/include/linux/pci.h > index 540b377ca8f6..2c413a64d168 100644 > --- a/include/linux/pci.h > +++ b/include/linux/pci.h > @@ -526,6 +526,15 @@ static inline int pci_channel_offline(struct pci_dev *pdev) > return (pdev->error_state != pci_channel_io_normal); > } > > +/* > +* Currently in ACPI spec, for each PCI host bridge, PCI Segment Group number is > +* limited to a 16-bit value, therefore (int)-1 is not a valid PCI domain number, > +* and can be used as a sentinel value indicating >domain_nr is not set by the > +* driver (and CONFIG_PCI_DOMAINS_GENERIC=y archs will set it with > +* pci_bus_find_domain_nr()). > +*/ Fix comment indentation (follow style of other comments in this file). s/>domain_nr/->domain_nr/ > +#define PCI_DOMAIN_NR_NOT_SET (-1) > + > struct pci_host_bridge { > struct device dev; > struct pci_bus *bus; /* Root bus */ > @@ -533,6 +542,7 @@ struct pci_host_bridge { > struct pci_ops *child_ops; > void *sysdata; > int busnr; > + int domain_nr; > struct list_head windows; /* resource_entry */ > struct list_head dma_ranges; /* dma ranges resource list */ > u8 (*swizzle_irq)(struct pci_dev *, u8 *); /* Platform IRQ swizzler */ > -- > 2.30.2 >
On Tue, Jul 20, 2021 at 05:49:25PM -0500, Bjorn Helgaas wrote: > On Tue, Jul 20, 2021 at 09:44:22PM +0800, Boqun Feng wrote: > > Currently we retrieve the PCI domain number of the host bridge from the > > bus sysdata (or pci_config_window if PCI_DOMAINS_GENERIC=y). Actually > > we have the information at PCI host bridge probing time, and it makes > > sense that we store it into pci_host_bridge. One benefit of doing so is > > the requirement for supporting PCI on Hyper-V for ARM64, because the > > host bridge of Hyper-V doesn't have pci_config_window, whereas ARM64 is > > a PCI_DOMAINS_GENERIC=y arch, so we cannot retrieve the PCI domain > > number from pci_config_window on ARM64 Hyper-V guest. > > > > As the preparation for ARM64 Hyper-V PCI support, we introduce the > > domain_nr in pci_host_bridge and a sentinel value to allow drivers to > > set domain numbers properly at probing time. Currently > > CONFIG_PCI_DOMAINS_GENERIC=y archs are only users of this > > newly-introduced field. > > > > Signed-off-by: Boqun Feng <boqun.feng@gmail.com> > > Once all the issues are ironed out, Lorenzo should probably merge this > since it's primarily Hyper-V stuff, but I'm OK with this part: > > Acked-by: Bjorn Helgaas <bhelgaas@google.com> > Thanks! > But fix the comment issue below. > Just send a v5.1 for this patch with the comment fixed and your Acked-by. Regards, Boqun > > --- > > drivers/pci/probe.c | 6 +++++- > > include/linux/pci.h | 10 ++++++++++ > > 2 files changed, 15 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c > > index 79177ac37880..60c50d4f156f 100644 > > --- a/drivers/pci/probe.c > > +++ b/drivers/pci/probe.c > > @@ -594,6 +594,7 @@ static void pci_init_host_bridge(struct pci_host_bridge *bridge) > > bridge->native_pme = 1; > > bridge->native_ltr = 1; > > bridge->native_dpc = 1; > > + bridge->domain_nr = PCI_DOMAIN_NR_NOT_SET; > > > > device_initialize(&bridge->dev); > > } > > @@ -898,7 +899,10 @@ static int pci_register_host_bridge(struct pci_host_bridge *bridge) > > bus->ops = bridge->ops; > > bus->number = bus->busn_res.start = bridge->busnr; > > #ifdef CONFIG_PCI_DOMAINS_GENERIC > > - bus->domain_nr = pci_bus_find_domain_nr(bus, parent); > > + if (bridge->domain_nr == PCI_DOMAIN_NR_NOT_SET) > > + bus->domain_nr = pci_bus_find_domain_nr(bus, parent); > > + else > > + bus->domain_nr = bridge->domain_nr; > > #endif > > > > b = pci_find_bus(pci_domain_nr(bus), bridge->busnr); > > diff --git a/include/linux/pci.h b/include/linux/pci.h > > index 540b377ca8f6..2c413a64d168 100644 > > --- a/include/linux/pci.h > > +++ b/include/linux/pci.h > > @@ -526,6 +526,15 @@ static inline int pci_channel_offline(struct pci_dev *pdev) > > return (pdev->error_state != pci_channel_io_normal); > > } > > > > +/* > > +* Currently in ACPI spec, for each PCI host bridge, PCI Segment Group number is > > +* limited to a 16-bit value, therefore (int)-1 is not a valid PCI domain number, > > +* and can be used as a sentinel value indicating >domain_nr is not set by the > > +* driver (and CONFIG_PCI_DOMAINS_GENERIC=y archs will set it with > > +* pci_bus_find_domain_nr()). > > +*/ > > Fix comment indentation (follow style of other comments in this file). > > s/>domain_nr/->domain_nr/ > > > +#define PCI_DOMAIN_NR_NOT_SET (-1) > > + > > struct pci_host_bridge { > > struct device dev; > > struct pci_bus *bus; /* Root bus */ > > @@ -533,6 +542,7 @@ struct pci_host_bridge { > > struct pci_ops *child_ops; > > void *sysdata; > > int busnr; > > + int domain_nr; > > struct list_head windows; /* resource_entry */ > > struct list_head dma_ranges; /* dma ranges resource list */ > > u8 (*swizzle_irq)(struct pci_dev *, u8 *); /* Platform IRQ swizzler */ > > -- > > 2.30.2 > >
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index 79177ac37880..60c50d4f156f 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -594,6 +594,7 @@ static void pci_init_host_bridge(struct pci_host_bridge *bridge) bridge->native_pme = 1; bridge->native_ltr = 1; bridge->native_dpc = 1; + bridge->domain_nr = PCI_DOMAIN_NR_NOT_SET; device_initialize(&bridge->dev); } @@ -898,7 +899,10 @@ static int pci_register_host_bridge(struct pci_host_bridge *bridge) bus->ops = bridge->ops; bus->number = bus->busn_res.start = bridge->busnr; #ifdef CONFIG_PCI_DOMAINS_GENERIC - bus->domain_nr = pci_bus_find_domain_nr(bus, parent); + if (bridge->domain_nr == PCI_DOMAIN_NR_NOT_SET) + bus->domain_nr = pci_bus_find_domain_nr(bus, parent); + else + bus->domain_nr = bridge->domain_nr; #endif b = pci_find_bus(pci_domain_nr(bus), bridge->busnr); diff --git a/include/linux/pci.h b/include/linux/pci.h index 540b377ca8f6..2c413a64d168 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -526,6 +526,15 @@ static inline int pci_channel_offline(struct pci_dev *pdev) return (pdev->error_state != pci_channel_io_normal); } +/* +* Currently in ACPI spec, for each PCI host bridge, PCI Segment Group number is +* limited to a 16-bit value, therefore (int)-1 is not a valid PCI domain number, +* and can be used as a sentinel value indicating >domain_nr is not set by the +* driver (and CONFIG_PCI_DOMAINS_GENERIC=y archs will set it with +* pci_bus_find_domain_nr()). +*/ +#define PCI_DOMAIN_NR_NOT_SET (-1) + struct pci_host_bridge { struct device dev; struct pci_bus *bus; /* Root bus */ @@ -533,6 +542,7 @@ struct pci_host_bridge { struct pci_ops *child_ops; void *sysdata; int busnr; + int domain_nr; struct list_head windows; /* resource_entry */ struct list_head dma_ranges; /* dma ranges resource list */ u8 (*swizzle_irq)(struct pci_dev *, u8 *); /* Platform IRQ swizzler */
Currently we retrieve the PCI domain number of the host bridge from the bus sysdata (or pci_config_window if PCI_DOMAINS_GENERIC=y). Actually we have the information at PCI host bridge probing time, and it makes sense that we store it into pci_host_bridge. One benefit of doing so is the requirement for supporting PCI on Hyper-V for ARM64, because the host bridge of Hyper-V doesn't have pci_config_window, whereas ARM64 is a PCI_DOMAINS_GENERIC=y arch, so we cannot retrieve the PCI domain number from pci_config_window on ARM64 Hyper-V guest. As the preparation for ARM64 Hyper-V PCI support, we introduce the domain_nr in pci_host_bridge and a sentinel value to allow drivers to set domain numbers properly at probing time. Currently CONFIG_PCI_DOMAINS_GENERIC=y archs are only users of this newly-introduced field. Signed-off-by: Boqun Feng <boqun.feng@gmail.com> --- drivers/pci/probe.c | 6 +++++- include/linux/pci.h | 10 ++++++++++ 2 files changed, 15 insertions(+), 1 deletion(-)