| Message ID | 1456843449-19393-2-git-send-email-lorenzo.pieralisi@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
[Replying to self] On Tue, Mar 01, 2016 at 02:44:07PM +0000, Lorenzo Pieralisi wrote: > From: Lorenzo Pieralisi <Lorenzo.Pieralisi@arm.com> > > PCI core code contains a set of functions, eg: > > pci_assign_unassigned_bus_resources() > > that allow to assign the PCI resources for a given bus after > enumeration. > > On systems where the PCI BARs are immutable (ie they must not and can > not be assigned), PCI bus resources should still be inserted in the PCI > resources tree (even if they are not (re)-assigned), but there is > no generic PCI kernel function for that purpose. Currently the PCI bus > resources insertion in the resources tree is implemented in an arch > specific fashion through arch specific callbacks that rely on the PCI > resources claiming API (for bridges and devices) which resulted in arches > implementations that contain duplicated code to claim resources for a > given PCI bus hierarchy. > > This patch, based on the x86/ia64 resources claiming arch implementations, > implements a set of functions in core PCI code that provides a PCI core > interface for resources claiming for a given PCI bus hierarchy, paving > the way for further resource claiming consolidation across architectures. > > Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> > Cc: Arnd Bergmann <arnd@arndb.de> > Cc: Bjorn Helgaas <bhelgaas@google.com> > Cc: Yinghai Lu <yinghai@kernel.org> > --- > drivers/pci/setup-bus.c | 68 +++++++++++++++++++++++++++++++++++++++++++++++++ > include/linux/pci.h | 1 + > 2 files changed, 69 insertions(+) I have v3 ready, which does not change this patch, however I have some questions below before asking to merge it. > diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c > index 7796d0a..95f0906 100644 > --- a/drivers/pci/setup-bus.c > +++ b/drivers/pci/setup-bus.c > @@ -1424,6 +1424,74 @@ void pci_bus_assign_resources(const struct pci_bus *bus) > } > EXPORT_SYMBOL(pci_bus_assign_resources); > > +static void pci_claim_device_resources(struct pci_dev *dev) > +{ > + int i; > + > + for (i = 0; i < PCI_BRIDGE_RESOURCES; i++) { > + struct resource *r = &dev->resource[i]; > + > + if (!r->flags || r->parent) > + continue; > + > + pci_claim_resource(dev, i); pci_claim_resource() (and in particular pci_find_parent_resource()) fails if resource.start == 0x0. Is this intentional ? The resource.start == 0x0 check is used in other bits of the kernel to detect an "invalid" resource, I am not sure I understand its implications correctly. > + } > +} > + > +static void pci_claim_bridge_resources(struct pci_dev *dev) > +{ > + int i; > + > + for (i = PCI_BRIDGE_RESOURCES; i < PCI_NUM_RESOURCES; i++) { > + struct resource *r = &dev->resource[i]; > + > + if (!r->flags || r->parent) > + continue; > + > + pci_claim_bridge_resource(dev, i); > + } > +} > + > +static void pci_bus_allocate_dev_resources(struct pci_bus *b) > +{ > + struct pci_dev *dev; > + struct pci_bus *child; > + > + list_for_each_entry(dev, &b->devices, bus_list) { > + pci_claim_device_resources(dev); > + > + child = dev->subordinate; > + if (child) > + pci_bus_allocate_dev_resources(child); > + } > +} > + > +static void pci_bus_allocate_resources(struct pci_bus *b) > +{ > + struct pci_bus *child; > + > + /* > + * Carry out a depth-first search on the PCI bus > + * tree to allocate bridge apertures. Read the > + * programmed bridge bases and recursively claim > + * the respective bridge resources. > + */ > + if (b->self) { Is it *always* correct to check b->self to detect a device backing the PCI bridge ? All PCI bridges should have their ->self pointer set-up correctly, I wanted to countercheck anyway. Comments welcome, thanks. Lorenzo > + pci_read_bridge_bases(b); > + pci_claim_bridge_resources(b->self); > + } > + > + list_for_each_entry(child, &b->children, node) > + pci_bus_allocate_resources(child); > +} > + > +void pci_bus_claim_resources(struct pci_bus *b) > +{ > + pci_bus_allocate_resources(b); > + pci_bus_allocate_dev_resources(b); > +} > +EXPORT_SYMBOL(pci_bus_claim_resources); > + > static void __pci_bridge_assign_resources(const struct pci_dev *bridge, > struct list_head *add_head, > struct list_head *fail_head) > diff --git a/include/linux/pci.h b/include/linux/pci.h > index 2771625..e66eba7 100644 > --- a/include/linux/pci.h > +++ b/include/linux/pci.h > @@ -1102,6 +1102,7 @@ ssize_t pci_write_vpd(struct pci_dev *dev, loff_t pos, size_t count, const void > /* Helper functions for low-level code (drivers/pci/setup-[bus,res].c) */ > resource_size_t pcibios_retrieve_fw_addr(struct pci_dev *dev, int idx); > void pci_bus_assign_resources(const struct pci_bus *bus); > +void pci_bus_claim_resources(struct pci_bus *bus); > void pci_bus_size_bridges(struct pci_bus *bus); > int pci_claim_resource(struct pci_dev *, int); > int pci_claim_bridge_resource(struct pci_dev *bridge, int i); > -- > 2.5.1 > -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c index 7796d0a..95f0906 100644 --- a/drivers/pci/setup-bus.c +++ b/drivers/pci/setup-bus.c @@ -1424,6 +1424,74 @@ void pci_bus_assign_resources(const struct pci_bus *bus) } EXPORT_SYMBOL(pci_bus_assign_resources); +static void pci_claim_device_resources(struct pci_dev *dev) +{ + int i; + + for (i = 0; i < PCI_BRIDGE_RESOURCES; i++) { + struct resource *r = &dev->resource[i]; + + if (!r->flags || r->parent) + continue; + + pci_claim_resource(dev, i); + } +} + +static void pci_claim_bridge_resources(struct pci_dev *dev) +{ + int i; + + for (i = PCI_BRIDGE_RESOURCES; i < PCI_NUM_RESOURCES; i++) { + struct resource *r = &dev->resource[i]; + + if (!r->flags || r->parent) + continue; + + pci_claim_bridge_resource(dev, i); + } +} + +static void pci_bus_allocate_dev_resources(struct pci_bus *b) +{ + struct pci_dev *dev; + struct pci_bus *child; + + list_for_each_entry(dev, &b->devices, bus_list) { + pci_claim_device_resources(dev); + + child = dev->subordinate; + if (child) + pci_bus_allocate_dev_resources(child); + } +} + +static void pci_bus_allocate_resources(struct pci_bus *b) +{ + struct pci_bus *child; + + /* + * Carry out a depth-first search on the PCI bus + * tree to allocate bridge apertures. Read the + * programmed bridge bases and recursively claim + * the respective bridge resources. + */ + if (b->self) { + pci_read_bridge_bases(b); + pci_claim_bridge_resources(b->self); + } + + list_for_each_entry(child, &b->children, node) + pci_bus_allocate_resources(child); +} + +void pci_bus_claim_resources(struct pci_bus *b) +{ + pci_bus_allocate_resources(b); + pci_bus_allocate_dev_resources(b); +} +EXPORT_SYMBOL(pci_bus_claim_resources); + static void __pci_bridge_assign_resources(const struct pci_dev *bridge, struct list_head *add_head, struct list_head *fail_head) diff --git a/include/linux/pci.h b/include/linux/pci.h index 2771625..e66eba7 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -1102,6 +1102,7 @@ ssize_t pci_write_vpd(struct pci_dev *dev, loff_t pos, size_t count, const void /* Helper functions for low-level code (drivers/pci/setup-[bus,res].c) */ resource_size_t pcibios_retrieve_fw_addr(struct pci_dev *dev, int idx); void pci_bus_assign_resources(const struct pci_bus *bus); +void pci_bus_claim_resources(struct pci_bus *bus); void pci_bus_size_bridges(struct pci_bus *bus); int pci_claim_resource(struct pci_dev *, int); int pci_claim_bridge_resource(struct pci_dev *bridge, int i);