[PATCH 04/12] x86/PCI: supply root bus resources to pci_create_bus()

From: Bjorn Helgaas
Date: Mon Oct 10 2011 - 23:18:52 EST


Parse ACPI host bridge _CRS resources first, so we can build a list of
resources available on the root bus and pass it to pci_create_bus().

Note that as before, we parse the ACPI _CRS even if we aren't paying
attention to it so we can print it for debugging purposes.

Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
---
arch/x86/pci/acpi.c | 41 ++++++++++++++++++++++++++---------------
1 files changed, 26 insertions(+), 15 deletions(-)

diff --git a/arch/x86/pci/acpi.c b/arch/x86/pci/acpi.c
index 9bf7aaa..6269545 100644
--- a/arch/x86/pci/acpi.c
+++ b/arch/x86/pci/acpi.c
@@ -12,7 +12,7 @@ struct pci_root_info {
char *name;
unsigned int res_num;
struct resource *res;
- struct pci_bus *bus;
+ struct list_head *resources;
int busnum;
};

@@ -250,27 +250,27 @@ static void add_resources(struct pci_root_info *info)
"ignoring host bridge window %pR (conflicts with %s %pR)\n",
res, conflict->name, conflict);
else
- pci_bus_add_resource(info->bus, res, 0);
+ pci_add_resource(info->resources, res);
}
}

-static void
-get_current_resources(struct acpi_device *device, int busnum,
- int domain, struct pci_bus *bus)
+static struct list_head *
+get_current_resources(struct acpi_device *device, int busnum, int domain)
{
struct pci_root_info info;
size_t size;

- if (pci_use_crs)
- pci_bus_remove_resources(bus);
-
info.bridge = device;
- info.bus = bus;
info.res_num = 0;
+ info.resources = kmalloc(sizeof(struct list_head), GFP_KERNEL);
+ if (!info.resources)
+ return NULL;
+
+ INIT_LIST_HEAD(info.resources);
acpi_walk_resources(device->handle, METHOD_NAME__CRS, count_resource,
&info);
if (!info.res_num)
- return;
+ goto res_alloc_fail;

size = sizeof(*info.res) * info.res_num;
info.res = kmalloc(size, GFP_KERNEL);
@@ -286,12 +286,12 @@ get_current_resources(struct acpi_device *device, int busnum,
&info);

add_resources(&info);
- return;
+ return info.resources;

name_alloc_fail:
kfree(info.res);
res_alloc_fail:
- return;
+ return info.resources;
}

struct pci_bus * __devinit pci_acpi_scan_root(struct acpi_pci_root *root)
@@ -299,6 +299,7 @@ struct pci_bus * __devinit pci_acpi_scan_root(struct acpi_pci_root *root)
struct acpi_device *device = root->device;
int domain = root->segment;
int busnum = root->secondary.start;
+ struct list_head *resources;
struct pci_bus *bus;
struct pci_sysdata *sd;
int node;
@@ -353,11 +354,21 @@ struct pci_bus * __devinit pci_acpi_scan_root(struct acpi_pci_root *root)
memcpy(bus->sysdata, sd, sizeof(*sd));
kfree(sd);
} else {
- bus = pci_create_bus(NULL, busnum, &pci_root_ops, sd, NULL);
- if (bus) {
- get_current_resources(device, busnum, domain, bus);
+ resources = get_current_resources(device, busnum, domain);
+ if (!pci_use_crs) {
+ pci_free_resource_list(resources);
+ resources = NULL;
+ }
+
+ bus = pci_create_bus(NULL, busnum, &pci_root_ops, sd,
+ resources);
+ if (bus)
bus->subordinate = pci_scan_child_bus(bus);
+ else {
+ if (resources)
+ pci_free_resource_list(resources);
}
+ kfree(resources);
}

/* After the PCI-E bus has been walked and all devices discovered,

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