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| author | Boqun Feng <boqun.feng@gmail.com> | 2021-07-27 02:06:50 +0800 |
|---|---|---|
| committer | Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> | 2021-08-23 10:59:26 +0100 |
| commit | 15d82ca23c996d50062286d27ed6a42a8105c04a (patch) | |
| tree | 9cd2e429798627d35f07c193be7ee87c01dc7d6f /include/linux/pci.h | |
| parent | e73f0f0ee7541171d89f2e2491130c7771ba58d3 (diff) | |
PCI: Introduce domain_nr in pci_host_bridge
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.
Link: https://lore.kernel.org/r/20210726180657.142727-2-boqun.feng@gmail.com
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Diffstat (limited to 'include/linux/pci.h')
| -rw-r--r-- | include/linux/pci.h | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/include/linux/pci.h b/include/linux/pci.h index 540b377ca8f6..01aa201e1df0 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -526,6 +526,16 @@ 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 +543,7 @@ 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 */ |