Re: [PATCH 02/13] PCI: Add busn_res operation functions
From: Bjorn Helgaas <bhelgaas@google.com>
Date: 2012-01-30 15:29:19
Also in:
linux-pci, lkml
On Fri, Jan 27, 2012 at 6:49 PM, Yinghai Lu [off-list ref] wrote:
quoted hunk ↗ jump to hunk
will use them insert/update busn res in pci_bus Signed-off-by: Yinghai Lu <yinghai@kernel.org> --- drivers/pci/probe.c | 44 ++++++++++++++++++++++++++++++++++++++++++++ include/linux/pci.h | 3 +++ 2 files changed, 47 insertions(+), 0 deletions(-)diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index a114173..71261da 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c@@ -1622,6 +1622,50 @@ err_out:return NULL; } +void pci_bus_insert_busn_res(struct pci_bus *b, int bus, int bus_max) +{ + struct resource *res = &b->busn_res; + struct resource *parent_res = &iobusn_resource; + int ret; + + res->start = (pci_domain_nr(b) << 8) | bus; + res->end = (pci_domain_nr(b) << 8) | bus_max; + res->flags = IORESOURCE_BUS; + + if (!pci_is_root_bus(b)) + parent_res = &b->parent->busn_res; + + ret = insert_resource(parent_res, res); + + dev_printk(KERN_DEBUG, &b->dev, + "busn_res: %06llx-%06llx %s inserted under %06llx-%06llx\n", + (unsigned long long)res->start, + (unsigned long long)res->end, + ret ? "can not be" : "is", + (unsigned long long)parent_res->start, + (unsigned long long)parent_res->end);
Please update the %pR implementation so you can use it instead of having to fiddle around with start/end separately and casts.
+}
+
+void pci_bus_update_busn_res_end(struct pci_bus *b, int bus_max)
+{
+ struct resource *res = &b->busn_res;
+ unsigned long long old_end = res->end;
+
+ res->end &= ~0xff;
+ res->end |= bus_max;
This updates a resource in place, without removing it from the
resource tree and re-inserting it. Doesn't this make it possible to
corrupt the resource tree? For example, let's say you have this tree:
00-3f : host bridge A
00-1f : P2P bridge B
40-7f : host bridge C
Now you use pci_bus_update_busn_res_end() to update the resource for
P2P bridge B, setting its end to 5f. I think the resource tree is
now corrupted.
quoted hunk ↗ jump to hunk
+ dev_printk(KERN_DEBUG, &b->dev, + "busn_res: %06llx-%06llx end updated to %06llx-%06llx\n", + (unsigned long long)res->start, + old_end, + (unsigned long long)res->start, + (unsigned long long)res->end); +} + +void pci_bus_release_busn_res(struct pci_bus *b) +{ + release_resource(&b->busn_res); +} + struct pci_bus * __devinit pci_scan_root_bus(struct device *parent, int bus, struct pci_ops *ops, void *sysdata, struct list_head *resources) {diff --git a/include/linux/pci.h b/include/linux/pci.h index 94ad468..3da935c 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h@@ -665,6 +665,9 @@ struct pci_bus *pci_scan_bus(int bus, struct pci_ops *ops, void *sysdata);struct pci_bus *pci_create_root_bus(struct device *parent, int bus, struct pci_ops *ops, void *sysdata, struct list_head *resources); +void pci_bus_insert_busn_res(struct pci_bus *b, int bus, int busmax); +void pci_bus_update_busn_res_end(struct pci_bus *b, int busmax); +void pci_bus_release_busn_res(struct pci_bus *b); struct pci_bus * __devinit pci_scan_root_bus(struct device *parent, int bus, struct pci_ops *ops, void *sysdata, struct list_head *resources); -- 1.7.7