linux/drivers/pci/hotplug
Rafael J. Wysocki 202317a573 ACPI / scan: Add acpi_device objects for all device nodes in the namespace
Modify the ACPI namespace scanning code to register a struct
acpi_device object for every namespace node representing a device,
processor and so on, even if the device represented by that namespace
node is reported to be not present and not functional by _STA.

There are multiple reasons to do that.  First of all, it avoids
quite a lot of overhead when struct acpi_device objects are
deleted every time acpi_bus_trim() is run and then added again
by a subsequent acpi_bus_scan() for the same scope, although the
namespace objects they correspond to stay in memory all the time
(which always is the case on a vast majority of systems).

Second, it will allow user space to see that there are namespace
nodes representing devices that are not present at the moment and may
be added to the system.  It will also allow user space to evaluate
_SUN for those nodes to check what physical slots the "missing"
devices may be put into and it will make sense to add a sysfs
attribute for _STA evaluation after this change (that will be
useful for thermal management on some systems).

Next, it will help to consolidate the ACPI hotplug handling among
subsystems by making it possible to store hotplug-related information
in struct acpi_device objects in a standard common way.

Finally, it will help to avoid a race condition related to the
deletion of ACPI namespace nodes.  Namely, namespace nodes may be
deleted as a result of a table unload triggered by _EJ0 or _DCK.
If a hotplug notification for one of those nodes is triggered
right before the deletion and it executes a hotplug callback
via acpi_hotplug_execute(), the ACPI handle passed to that
callback may be stale when the callback actually runs.  One way
to work around that is to always pass struct acpi_device pointers
to hotplug callbacks after doing a get_device() on the objects in
question which eliminates the use-after-free possibility (the ACPI
handles in those objects are invalidated by acpi_scan_drop_device(),
so they will trigger ACPICA errors on attempts to use them).

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
2013-11-22 21:54:37 +01:00
..
acpi_pcihp.c ACPI: Eliminate the DEVICE_ACPI_HANDLE() macro 2013-11-14 23:17:21 +01:00
acpiphp_core.c PCI: Fix whitespace, capitalization, and spelling errors 2013-11-14 11:28:18 -07:00
acpiphp_glue.c ACPI / scan: Add acpi_device objects for all device nodes in the namespace 2013-11-22 21:54:37 +01:00
acpiphp_ibm.c PCI: Fix whitespace, capitalization, and spelling errors 2013-11-14 11:28:18 -07:00
acpiphp.h Merge branch 'acpi-hotplug' 2013-11-19 21:18:13 +01:00
cpci_hotplug_core.c PCI: Fix whitespace, capitalization, and spelling errors 2013-11-14 11:28:18 -07:00
cpci_hotplug_pci.c PCI: Fix whitespace, capitalization, and spelling errors 2013-11-14 11:28:18 -07:00
cpci_hotplug.h PCI: Remove "extern" from function declarations 2013-04-17 10:21:17 -06:00
cpcihp_generic.c PCI: Fix whitespace, capitalization, and spelling errors 2013-11-14 11:28:18 -07:00
cpcihp_zt5550.c PCI: Fix whitespace, capitalization, and spelling errors 2013-11-14 11:28:18 -07:00
cpcihp_zt5550.h PCI: Fix whitespace, capitalization, and spelling errors 2013-11-14 11:28:18 -07:00
cpqphp_core.c PCI: Fix whitespace, capitalization, and spelling errors 2013-11-14 11:28:18 -07:00
cpqphp_ctrl.c PCI: Fix whitespace, capitalization, and spelling errors 2013-11-14 11:28:18 -07:00
cpqphp_nvram.c PCI Hotplug: cpqphp: fix comment style 2009-06-11 12:04:08 -07:00
cpqphp_nvram.h PCI: Remove "extern" from function declarations 2013-04-17 10:21:17 -06:00
cpqphp_pci.c PCI: Fix whitespace, capitalization, and spelling errors 2013-11-14 11:28:18 -07:00
cpqphp_sysfs.c cpqphp_sysfs: switch to fixed_size_llseek() 2013-06-29 12:57:52 +04:00
cpqphp.h PCI: Remove "extern" from function declarations 2013-04-17 10:21:17 -06:00
ibmphp_core.c PCI: Fix whitespace, capitalization, and spelling errors 2013-11-14 11:28:18 -07:00
ibmphp_ebda.c PCI: Fix whitespace, capitalization, and spelling errors 2013-11-14 11:28:18 -07:00
ibmphp_hpc.c PCI: Fix whitespace, capitalization, and spelling errors 2013-11-14 11:28:18 -07:00
ibmphp_pci.c PCI: Fix whitespace, capitalization, and spelling errors 2013-11-14 11:28:18 -07:00
ibmphp_res.c PCI: Fix whitespace, capitalization, and spelling errors 2013-11-14 11:28:18 -07:00
ibmphp.h PCI: Fix whitespace, capitalization, and spelling errors 2013-11-14 11:28:18 -07:00
Kconfig PCI: Fix whitespace, capitalization, and spelling errors 2013-11-14 11:28:18 -07:00
Makefile PCI: Fix whitespace, capitalization, and spelling errors 2013-11-14 11:28:18 -07:00
pci_hotplug_core.c PCI: Fix whitespace, capitalization, and spelling errors 2013-11-14 11:28:18 -07:00
pciehp_acpi.c PCI updates for v3.13: 2013-11-22 10:53:47 -08:00
pciehp_core.c PCI: Fix whitespace, capitalization, and spelling errors 2013-11-14 11:28:18 -07:00
pciehp_ctrl.c PCI: pciehp: Use per-slot workqueues to avoid deadlock 2013-01-12 13:56:33 -07:00
pciehp_hpc.c PCI: Fix whitespace, capitalization, and spelling errors 2013-11-14 11:28:18 -07:00
pciehp_pci.c PCI: pciehp: Fix null pointer deref when hot-removing SR-IOV device 2013-07-25 14:11:06 -06:00
pciehp.h PCI: Fix whitespace, capitalization, and spelling errors 2013-11-14 11:28:18 -07:00
pcihp_skeleton.c PCI: Fix whitespace, capitalization, and spelling errors 2013-11-14 11:28:18 -07:00
pcihp_slot.c PCI: Simplify pcie_bus_configure_settings() interface 2013-08-22 10:47:02 -06:00
rpadlpar_core.c PCI: Fix whitespace, capitalization, and spelling errors 2013-11-14 11:28:18 -07:00
rpadlpar_sysfs.c
rpadlpar.h PCI: Remove "extern" from function declarations 2013-04-17 10:21:17 -06:00
rpaphp_core.c PCI: Fix whitespace, capitalization, and spelling errors 2013-11-14 11:28:18 -07:00
rpaphp_pci.c PCI: Fix whitespace, capitalization, and spelling errors 2013-11-14 11:28:18 -07:00
rpaphp_slot.c PCI: Fix whitespace, capitalization, and spelling errors 2013-11-14 11:28:18 -07:00
rpaphp.h PCI: Fix whitespace, capitalization, and spelling errors 2013-11-14 11:28:18 -07:00
s390_pci_hpc.c s390/pci: message cleanup 2013-10-24 17:17:15 +02:00
sgi_hotplug.c ACPI / driver core: Store an ACPI device pointer in struct acpi_dev_node 2013-11-14 23:14:43 +01:00
shpchp_core.c PCI: Fix whitespace, capitalization, and spelling errors 2013-11-14 11:28:18 -07:00
shpchp_ctrl.c PCI: shpchp: Use per-slot workqueues to avoid deadlock 2013-01-14 10:23:22 -07:00
shpchp_hpc.c PCI: Fix whitespace, capitalization, and spelling errors 2013-11-14 11:28:18 -07:00
shpchp_pci.c PCI: shpchp: Iterate over all devices in slot, not functions 0-7 2013-01-25 09:23:08 -07:00
shpchp_sysfs.c PCI: Remove __must_check from definitions 2013-04-17 10:20:58 -06:00
shpchp.h PCI: Fix whitespace, capitalization, and spelling errors 2013-11-14 11:28:18 -07:00