Re: [RFC PATCH 07/16] PCI: Separate pci_host_bridge creation out of pci_create_root_bus()
From: Arnd Bergmann <arnd@arndb.de>
Date: 2014-11-17 10:57:56
Also in:
linux-arm-kernel, linux-pci, lkml
On Monday 17 November 2014 18:21:41 Yijing Wang wrote:
quoted hunk ↗ jump to hunk
There are some common PCI infos like domain, msi_controller, these infos are saved in arch PCI sysdata, and lots arch specific functions like pci_domain_nr() and pcibios_msi_controller() required. We could separate pci_host_bridge creation out of pci_create_root_bus(), then we could put the common infos in, then we could eliminate the arch specifc functions. Signed-off-by: Yijing Wang <redacted> --- drivers/pci/host-bridge.c | 99 +++++++++++++++++++++++++++++++++ drivers/pci/probe.c | 134 ++++++++++++++++---------------------------- include/linux/pci.h | 11 +++- 3 files changed, 158 insertions(+), 86 deletions(-)diff --git a/drivers/pci/host-bridge.c b/drivers/pci/host-bridge.c index 0e5f3c9..e31604f 100644 --- a/drivers/pci/host-bridge.c +++ b/drivers/pci/host-bridge.c@@ -8,6 +8,105 @@ #include "pci.h" +LIST_HEAD(pci_host_bridge_list); +DECLARE_RWSEM(pci_host_bridge_sem);
Unless the pci_host_bridge_sem is accessed thousands of times per second, it's normally better to use a simple mutex instead.
+static struct resource busn_resource = {
+ .name = "PCI busn",
+ .start = 0,
+ .end = 255,
+ .flags = IORESOURCE_BUS,
+};I think it would be better to require callers to pass the bus resource down to the function.
+struct pci_host_bridge *pci_create_host_bridge(
+ struct device *parent, u32 db,
+ struct pci_ops *ops, void *sysdata,
+ struct list_head *resources)
+{Do we still need to pass the 'sysdata' in here? If we are guaranteed to have a device pointer, we should always be able to get the driver private data from dev_get_drvdata(host->dev->parent).
+ host = kzalloc(sizeof(*host), GFP_KERNEL); + if (!host) + return NULL;
devm_kzalloc maybe?
+ if (!resources) {
+ /* Use default IO/MEM/BUS resources*/
+ pci_add_resource(&host->windows, &ioport_resource);
+ pci_add_resource(&host->windows, &iomem_resource);
+ pci_add_resource(&host->windows, &busn_resource);
+ } else {
+ list_for_each_entry_safe(window, n, resources, list)
+ list_move_tail(&window->list, &host->windows);
+ }I think we should assume that the correct resources are passed. You could add a wrapper around this function to convert old platforms though.
+EXPORT_SYMBOL(pci_create_host_bridge);
EXPORT_SYMBOL_GPL() maybe?
quoted hunk ↗ jump to hunk
diff --git a/include/linux/pci.h b/include/linux/pci.h index 8b11b38..daa7f40 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h@@ -402,7 +402,12 @@ struct pci_host_bridge_window { struct pci_host_bridge { struct device dev; struct pci_bus *bus; /* root bus */ + struct list_head list; struct list_head windows; /* pci_host_bridge_windows */ + int busnum;
The busnum should already be implied through the bus resource. Arnd