[PATCH v9 06/16] PCI: introduce platform dependent hooks for creating/destroying PCI busses

[PATCH v9 06/16] PCI: introduce platform dependent hooks for creating/destroying PCI busses

[Jiang Liu]

On ACPI based platforms, the pci_slot driver creates PCI slot devices
according to information from ACPI tables by registering an ACPI PCI
subdriver. The ACPI PCI subdriver will only be called when creating/
destroying PCI root buses, and it won't be called when hot-plugging
P2P bridges. It may cause stale PCI slot devices after hot-removing
a P2P bridge if that bridge has associated PCI slots. And the acpiphp
driver has the same issue too.

This patch introduces two hook points into the PCI core, which will
be invoked when creating/destroying PCI busses for PCI host and P2P
bridges. They could be used to setup/destroy platform dependent staffs
in a unified way, both at boot time and for PCI hotplug operations.

Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Signed-off-by: Yijing Wang <wangyijing@huawei.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Cc: Toshi Kani <toshi.kani@hp.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Myron Stowe <myron.stowe@redhat.com>
Cc: linux-pci@vger.kernel.org
Cc: linux-ia64@vger.kernel.org
Cc: x86@kernel.org
Cc: linux-kernel@vger.kernel.org
---
 drivers/pci/probe.c  |   12 ++++++++++++
 drivers/pci/remove.c |    1 +
 include/linux/pci.h  |    2 ++
 3 files changed, 15 insertions(+)

diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 45c93b3..43ece5d 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -673,6 +673,8 @@ add_dev:
 	ret = device_register(&child->dev);
 	WARN_ON(ret < 0);
 
+	pcibios_add_bus(child);
+
 	/* Create legacy_io and legacy_mem files for this bus */
 	pci_create_legacy_files(child);
 
@@ -1660,6 +1662,14 @@ int __weak pcibios_root_bridge_prepare(struct pci_host_bridge *bridge)
 	return 0;
 }
 
+void __weak pcibios_add_bus(struct pci_bus *bus)
+{
+}
+
+void __weak pcibios_remove_bus(struct pci_bus *bus)
+{
+}
+
 struct pci_bus *pci_create_root_bus(struct device *parent, int bus,
 		struct pci_ops *ops, void *sysdata, struct list_head *resources)
 {
@@ -1714,6 +1724,8 @@ struct pci_bus *pci_create_root_bus(struct device *parent, int bus,
 	if (error)
 		goto class_dev_reg_err;
 
+	pcibios_add_bus(b);
+
 	/* Create legacy_io and legacy_mem files for this bus */
 	pci_create_legacy_files(b);
 
diff --git a/drivers/pci/remove.c b/drivers/pci/remove.c
index a831880..8fc54b7 100644
--- a/drivers/pci/remove.c
+++ b/drivers/pci/remove.c
@@ -51,6 +51,7 @@ void pci_remove_bus(struct pci_bus *bus)
 	pci_bus_release_busn_res(bus);
 	up_write(&pci_bus_sem);
 	pci_remove_legacy_files(bus);
+	pcibios_remove_bus(bus);
 	device_unregister(&bus->dev);
 }
 EXPORT_SYMBOL(pci_remove_bus);
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 849a336..7eb6023 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -693,6 +693,8 @@ extern struct list_head pci_root_buses;	/* list of all known PCI buses */
 extern int no_pci_devices(void);
 
 void pcibios_resource_survey_bus(struct pci_bus *bus);
+void pcibios_add_bus(struct pci_bus *bus);
+void pcibios_remove_bus(struct pci_bus *bus);
 void pcibios_fixup_bus(struct pci_bus *);
 int __must_check pcibios_enable_device(struct pci_dev *, int mask);
 /* Architecture specific versions may override this (weak) */
-- 
1.7.9.5

[PATCH v9 07/16] PCI, ACPI: prepare stub functions to handle ACPI PCI (hotplug) slots

[Jiang Liu]

Prepare two stub functions to handle ACPI PCI slots and ACPI PCI hotplug
slots, which will be invoked by the PCI core when creating/destroying
PCI buses.

It will be used to get rid of ACPI PCI subdrivers for pci_slot and
acpiphp, and eventually remove the ACPI PCI subdriver mechanism.

And it will also be used to handle ACPI PCI (hotplug) slots in a unified
way, both at boot time and for PCI hotplug operations.

Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Signed-off-by: Yijing Wang <wangyijing@huawei.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Cc: Toshi Kani <toshi.kani@hp.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Myron Stowe <myron.stowe@redhat.com>
Cc: linux-pci@vger.kernel.org
Cc: linux-ia64@vger.kernel.org
Cc: x86@kernel.org
Cc: linux-kernel@vger.kernel.org
---
 drivers/pci/pci-acpi.c   |   24 ++++++++++++++++++++++++
 include/linux/pci-acpi.h |    8 +++++++-
 2 files changed, 31 insertions(+), 1 deletion(-)

diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c
index dee5ddd..b8b8437 100644
--- a/drivers/pci/pci-acpi.c
+++ b/drivers/pci/pci-acpi.c
@@ -287,6 +287,30 @@ static struct pci_platform_pm_ops acpi_pci_platform_pm = {
 	.run_wake = acpi_pci_run_wake,
 };
 
+void acpi_pci_add_bus(struct pci_bus *bus)
+{
+	acpi_handle handle = NULL;
+
+	if (bus->bridge)
+		handle = ACPI_HANDLE(bus->bridge);
+	if (acpi_pci_disabled || handle = NULL)
+		return;
+
+	/* TODO: add PCI slots and acpiphp hotplug slots */
+}
+
+void acpi_pci_remove_bus(struct pci_bus *bus)
+{
+	/*
+	 * bus->bridge->acpi_node.handle has already been reset to NULL
+	 * when acpi_pci_remove_bus() is called, so don't check ACPI handle.
+	 */
+	if (acpi_pci_disabled)
+		return;
+
+	/* TODO: remove PCI slots and acpiphp hotplug slots */
+}
+
 /* ACPI bus type */
 static int acpi_pci_find_device(struct device *dev, acpi_handle *handle)
 {
diff --git a/include/linux/pci-acpi.h b/include/linux/pci-acpi.h
index 9a22b5e..2b1743c 100644
--- a/include/linux/pci-acpi.h
+++ b/include/linux/pci-acpi.h
@@ -41,7 +41,13 @@ static inline acpi_handle acpi_pci_get_bridge_handle(struct pci_bus *pbus)
 
 	return DEVICE_ACPI_HANDLE(dev);
 }
-#endif
+
+void acpi_pci_add_bus(struct pci_bus *bus);
+void acpi_pci_remove_bus(struct pci_bus *bus);
+#else	/* CONFIG_ACPI */
+static inline void acpi_pci_add_bus(struct pci_bus *bus) { }
+static inline void acpi_pci_remove_bus(struct pci_bus *bus) { }
+#endif	/* CONFIG_ACPI */
 
 #ifdef CONFIG_ACPI_APEI
 extern bool aer_acpi_firmware_first(void);
-- 
1.7.9.5

[PATCH v9 08/16] PCI, IA64: implement pcibios_{add|remove}_bus() hooks

[Jiang Liu]

Implement pcibios_{add|remove}_bus() hooks for IA64 platforms.

Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Signed-off-by: Yijing Wang <wangyijing@huawei.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Cc: Toshi Kani <toshi.kani@hp.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: linux-ia64@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
---
 arch/ia64/pci/pci.c |   11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/arch/ia64/pci/pci.c b/arch/ia64/pci/pci.c
index 60532ab..de1474f 100644
--- a/arch/ia64/pci/pci.c
+++ b/arch/ia64/pci/pci.c
@@ -15,6 +15,7 @@
 #include <linux/types.h>
 #include <linux/kernel.h>
 #include <linux/pci.h>
+#include <linux/pci-acpi.h>
 #include <linux/init.h>
 #include <linux/ioport.h>
 #include <linux/slab.h>
@@ -458,6 +459,16 @@ void pcibios_fixup_bus(struct pci_bus *b)
 	platform_pci_fixup_bus(b);
 }
 
+void pcibios_add_bus(struct pci_bus *bus)
+{
+	acpi_pci_add_bus(bus);
+}
+
+void pcibios_remove_bus(struct pci_bus *bus)
+{
+	acpi_pci_remove_bus(bus);
+}
+
 void pcibios_set_master (struct pci_dev *dev)
 {
 	/* No special bus mastering setup handling */
-- 
1.7.9.5