[RFC PATCH 11/16] x86/PCI: Use pci_scan_host_bridge() instead of pci_create_root_bus()

Yijing Wang
2014-11-17T10:21:45Z

Now we could use pci_scan_host_bridge() to refactor
pci_acpi_scan_root().

Signed-off-by: Yijing Wang <wangyijing@huawei.com>
---
arch/x86/pci/acpi.c | 65 ++++++++++++++++++++++++++++++-------------------
arch/x86/pci/common.c | 23 ++++++++++++-----
2 files changed, 56 insertions(+), 32 deletions(-)

diff --git a/arch/x86/pci/acpi.c b/arch/x86/pci/acpi.c
index cfd1b13..528fca3 100644
--- a/arch/x86/pci/acpi.c
+++ b/arch/x86/pci/acpi.c
@@ -13,6 +13,7 @@ struct pci_root_info {
unsigned int res_num;
struct resource *res;
resource_size_t *res_offset;
+ struct acpi_pci_root *root;
struct pci_sysdata sd;
#ifdef CONFIG_PCI_MMCONFIG
bool mcfg_added;
@@ -467,16 +468,40 @@ static void probe_pci_root_info(struct pci_root_info *info,
info);
}

+static int pci_acpi_init_res(struct pci_host_bridge *host,
+ struct pci_host_info *arg)
+{
+ struct pci_sysdata *sd = arg->arg;
+ struct pci_root_info *info = container_of(sd,
+ struct pci_root_info, sd);
+
+ /* insert busn res at first */
+ pci_add_resource(&host->windows, &info->root->secondary);
+ /*
+ * _CRS with no apertures is normal, so only fall back to
+ * defaults or native bridge info if we're ignoring _CRS.
+ */
+ if (pci_use_crs)
+ add_resources(info, &host->windows);
+ else {
+ free_pci_root_info_res(info);
+ x86_pci_root_bus_resources(host->busnum, &host->windows);
+ }
+
+ return 0;
+}
+
struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root)
{
struct acpi_device *device = root->device;
struct pci_root_info *info;
int domain = root->segment;
int busnum = root->secondary.start;
- LIST_HEAD(resources);
struct pci_bus *bus;
struct pci_sysdata *sd;
int node;
+ struct pci_host_info arg;
+ struct pci_host_bridge *host;

if (pci_ignore_seg)
domain = 0;
@@ -506,10 +531,14 @@ struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root)
return NULL;
}

+ info->root = root;
sd = &info->sd;
sd->domain = domain;
sd->node = node;
sd->companion = device;
+ init_pci_host_info(&arg);
+ arg.arg = sd;
+ arg.init_res = pci_acpi_init_res;

bus = pci_find_bus(domain, busnum);
if (bus) {
@@ -522,33 +551,19 @@ struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root)
} else {
probe_pci_root_info(info, device, busnum, domain);

- /* insert busn res at first */
- pci_add_resource(&resources, &root->secondary);
- /*
- * _CRS with no apertures is normal, so only fall back to
- * defaults or native bridge info if we're ignoring _CRS.
- */
- if (pci_use_crs)
- add_resources(info, &resources);
- else {
- free_pci_root_info_res(info);
- x86_pci_root_bus_resources(busnum, &resources);
+ if (!setup_mcfg_map(info, domain, (u8)root->secondary.start,
+ (u8)root->secondary.end, root->mcfg_addr)) {
+ host = pci_scan_host_bridge(NULL, PCI_DOMBUS(domain, busnum),
+ &pci_root_ops, &arg);
+ bus = host->bus;
}

- if (!setup_mcfg_map(info, domain, (u8)root->secondary.start,
- (u8)root->secondary.end, root->mcfg_addr))
- bus = pci_create_root_bus(NULL, busnum, &pci_root_ops,
- sd, &resources);
-
- if (bus) {
- pci_scan_child_bus(bus);
- pci_set_host_bridge_release(
- to_pci_host_bridge(bus->bridge),
+ if (bus)
+ pci_set_host_bridge_release(host,
release_pci_root_info, info);
- } else {
- pci_free_resource_list(&resources);
+ else
__release_pci_root_info(info);
- }
+
}

/* After the PCI-E bus has been walked and all devices discovered,
@@ -568,7 +583,7 @@ struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root)

int pcibios_root_bridge_prepare(struct pci_host_bridge *bridge)
{
- struct pci_sysdata *sd = bridge->bus->sysdata;
+ struct pci_sysdata *sd = bridge->sysdata;

ACPI_COMPANION_SET(&bridge->dev, sd->companion);
return 0;
diff --git a/arch/x86/pci/common.c b/arch/x86/pci/common.c
index b16632b..0032065 100644
--- a/arch/x86/pci/common.c
+++ b/arch/x86/pci/common.c
@@ -456,11 +456,18 @@ void __init dmi_check_pciprobe(void)
dmi_check_system(pciprobe_dmi_table);
}

+static int pcibios_init_res(struct pci_host_bridge *host,
+ struct pci_host_info *info)
+{
+ x86_pci_root_bus_resources(host->busnum, &host->windows);
+ return 0;
+}
+
void pcibios_scan_root(int busnum)
{
- struct pci_bus *bus;
struct pci_sysdata *sd;
- LIST_HEAD(resources);
+ struct pci_host_info info;
+ struct pci_host_bridge *host;

sd = kzalloc(sizeof(*sd), GFP_KERNEL);
if (!sd) {
@@ -468,14 +475,16 @@ void pcibios_scan_root(int busnum)
return;
}
sd->node = x86_pci_root_bus_node(busnum);
- x86_pci_root_bus_resources(busnum, &resources);
+ init_pci_host_info(&info);
+ info.init_res = pcibios_init_res;
+ info.arg = sd;
printk(KERN_DEBUG "PCI: Probing PCI hardware (bus %02x)\n", busnum);
- bus = pci_scan_root_bus(NULL, busnum, &pci_root_ops, sd, &resources);
- if (bus) {
- pci_bus_add_devices(bus);
+ host = pci_scan_host_bridge(NULL, PCI_DOMBUS(0, busnum),
+ &pci_root_ops, &info);
+ if (host) {
+ pci_bus_add_devices(host->bus);
return;
}
- pci_free_resource_list(&resources);
kfree(sd);
}

--
1.7.1