linux/drivers/pci/hotplug/fakephp.c

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PCI Hotplug: restore fakephp interface with complete reimplementation A complete re-implementation of fakephp is necessary if it is to present its former interface (pre-2.6.27, when it broke). The reason is that PCI hotplug drivers call pci_hp_register(), which enforces the rule that only one /sys/bus/pci/slots/ file may be created per physical slot. The change breaks the old fakephp's assumption that it could create a file per function. So we re-implement fakephp to avoid using the standard PCI hotplug API so that we can restore the old fakephp user interface. It puts entries in /sys/bus/pci/slots with the names of all PCI devices/functions, exactly symmetrical to what is shown in /sys/bus/pci/devices. Each slots/ entry has a "power" attribute, which works the same way as the fakephp driver's power attribute has worked. There are a few improvements over old fakephp, which couldn't handle PCI devices being added or removed via a means outside of fakephp's knowledge. If a device was added another way, old fakephp didn't notice and didn't create the fake slot for it. If a device was removed another way, old fakephp didn't delete the fake slot for it (and accessing the stale slot caused an oops). The new implementation overcomes these limitations. As a consequence, removing a bridge with other devices behind it now works as well, which is something else old fakephp couldn't do previously. This duplicates a tiny bit of the code in the PCI core that does this same function. Re-using that code ends up being more complex than duplicating it, and it makes code in the PCI core more ugly just to support this legacy fakephp interface compatibility layer. Reviewed-by: James Cameron <qz@hp.com> Signed-off-by: Trent Piepho <xyzzy@speakeasy.org> Signed-off-by: Alex Chiang <achiang@hp.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2009-03-20 20:56:46 +00:00
/* Works like the fakephp driver used to, except a little better.
*
* - It's possible to remove devices with subordinate busses.
* - New PCI devices that appear via any method, not just a fakephp triggered
* rescan, will be noticed.
* - Devices that are removed via any method, not just a fakephp triggered
* removal, will also be noticed.
*
* Uses nothing from the pci-hotplug subsystem.
*
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/list.h>
#include <linux/kobject.h>
#include <linux/sysfs.h>
#include <linux/init.h>
#include <linux/pci.h>
#include <linux/device.h>
include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 08:04:11 +00:00
#include <linux/slab.h>
PCI Hotplug: restore fakephp interface with complete reimplementation A complete re-implementation of fakephp is necessary if it is to present its former interface (pre-2.6.27, when it broke). The reason is that PCI hotplug drivers call pci_hp_register(), which enforces the rule that only one /sys/bus/pci/slots/ file may be created per physical slot. The change breaks the old fakephp's assumption that it could create a file per function. So we re-implement fakephp to avoid using the standard PCI hotplug API so that we can restore the old fakephp user interface. It puts entries in /sys/bus/pci/slots with the names of all PCI devices/functions, exactly symmetrical to what is shown in /sys/bus/pci/devices. Each slots/ entry has a "power" attribute, which works the same way as the fakephp driver's power attribute has worked. There are a few improvements over old fakephp, which couldn't handle PCI devices being added or removed via a means outside of fakephp's knowledge. If a device was added another way, old fakephp didn't notice and didn't create the fake slot for it. If a device was removed another way, old fakephp didn't delete the fake slot for it (and accessing the stale slot caused an oops). The new implementation overcomes these limitations. As a consequence, removing a bridge with other devices behind it now works as well, which is something else old fakephp couldn't do previously. This duplicates a tiny bit of the code in the PCI core that does this same function. Re-using that code ends up being more complex than duplicating it, and it makes code in the PCI core more ugly just to support this legacy fakephp interface compatibility layer. Reviewed-by: James Cameron <qz@hp.com> Signed-off-by: Trent Piepho <xyzzy@speakeasy.org> Signed-off-by: Alex Chiang <achiang@hp.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2009-03-20 20:56:46 +00:00
#include "../pci.h"
struct legacy_slot {
struct kobject kobj;
struct pci_dev *dev;
struct list_head list;
};
static LIST_HEAD(legacy_list);
static ssize_t legacy_show(struct kobject *kobj, struct attribute *attr,
char *buf)
{
struct legacy_slot *slot = container_of(kobj, typeof(*slot), kobj);
strcpy(buf, "1\n");
return 2;
}
static void remove_callback(void *data)
{
pci_stop_and_remove_bus_device((struct pci_dev *)data);
PCI Hotplug: restore fakephp interface with complete reimplementation A complete re-implementation of fakephp is necessary if it is to present its former interface (pre-2.6.27, when it broke). The reason is that PCI hotplug drivers call pci_hp_register(), which enforces the rule that only one /sys/bus/pci/slots/ file may be created per physical slot. The change breaks the old fakephp's assumption that it could create a file per function. So we re-implement fakephp to avoid using the standard PCI hotplug API so that we can restore the old fakephp user interface. It puts entries in /sys/bus/pci/slots with the names of all PCI devices/functions, exactly symmetrical to what is shown in /sys/bus/pci/devices. Each slots/ entry has a "power" attribute, which works the same way as the fakephp driver's power attribute has worked. There are a few improvements over old fakephp, which couldn't handle PCI devices being added or removed via a means outside of fakephp's knowledge. If a device was added another way, old fakephp didn't notice and didn't create the fake slot for it. If a device was removed another way, old fakephp didn't delete the fake slot for it (and accessing the stale slot caused an oops). The new implementation overcomes these limitations. As a consequence, removing a bridge with other devices behind it now works as well, which is something else old fakephp couldn't do previously. This duplicates a tiny bit of the code in the PCI core that does this same function. Re-using that code ends up being more complex than duplicating it, and it makes code in the PCI core more ugly just to support this legacy fakephp interface compatibility layer. Reviewed-by: James Cameron <qz@hp.com> Signed-off-by: Trent Piepho <xyzzy@speakeasy.org> Signed-off-by: Alex Chiang <achiang@hp.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2009-03-20 20:56:46 +00:00
}
static ssize_t legacy_store(struct kobject *kobj, struct attribute *attr,
const char *buf, size_t len)
{
struct legacy_slot *slot = container_of(kobj, typeof(*slot), kobj);
unsigned long val;
if (strict_strtoul(buf, 0, &val) < 0)
return -EINVAL;
if (val)
pci_rescan_bus(slot->dev->bus);
else
sysfs_schedule_callback(&slot->dev->dev.kobj, remove_callback,
slot->dev, THIS_MODULE);
return len;
}
static struct attribute *legacy_attrs[] = {
&(struct attribute){ .name = "power", .mode = 0644 },
NULL,
};
static void legacy_release(struct kobject *kobj)
{
struct legacy_slot *slot = container_of(kobj, typeof(*slot), kobj);
pci_dev_put(slot->dev);
kfree(slot);
}
static struct kobj_type legacy_ktype = {
.sysfs_ops = &(const struct sysfs_ops){
PCI Hotplug: restore fakephp interface with complete reimplementation A complete re-implementation of fakephp is necessary if it is to present its former interface (pre-2.6.27, when it broke). The reason is that PCI hotplug drivers call pci_hp_register(), which enforces the rule that only one /sys/bus/pci/slots/ file may be created per physical slot. The change breaks the old fakephp's assumption that it could create a file per function. So we re-implement fakephp to avoid using the standard PCI hotplug API so that we can restore the old fakephp user interface. It puts entries in /sys/bus/pci/slots with the names of all PCI devices/functions, exactly symmetrical to what is shown in /sys/bus/pci/devices. Each slots/ entry has a "power" attribute, which works the same way as the fakephp driver's power attribute has worked. There are a few improvements over old fakephp, which couldn't handle PCI devices being added or removed via a means outside of fakephp's knowledge. If a device was added another way, old fakephp didn't notice and didn't create the fake slot for it. If a device was removed another way, old fakephp didn't delete the fake slot for it (and accessing the stale slot caused an oops). The new implementation overcomes these limitations. As a consequence, removing a bridge with other devices behind it now works as well, which is something else old fakephp couldn't do previously. This duplicates a tiny bit of the code in the PCI core that does this same function. Re-using that code ends up being more complex than duplicating it, and it makes code in the PCI core more ugly just to support this legacy fakephp interface compatibility layer. Reviewed-by: James Cameron <qz@hp.com> Signed-off-by: Trent Piepho <xyzzy@speakeasy.org> Signed-off-by: Alex Chiang <achiang@hp.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2009-03-20 20:56:46 +00:00
.store = legacy_store, .show = legacy_show
},
.release = &legacy_release,
.default_attrs = legacy_attrs,
};
static int legacy_add_slot(struct pci_dev *pdev)
{
struct legacy_slot *slot = kzalloc(sizeof(*slot), GFP_KERNEL);
if (!slot)
return -ENOMEM;
if (kobject_init_and_add(&slot->kobj, &legacy_ktype,
&pci_slots_kset->kobj, "%s",
dev_name(&pdev->dev))) {
PCI Hotplug: restore fakephp interface with complete reimplementation A complete re-implementation of fakephp is necessary if it is to present its former interface (pre-2.6.27, when it broke). The reason is that PCI hotplug drivers call pci_hp_register(), which enforces the rule that only one /sys/bus/pci/slots/ file may be created per physical slot. The change breaks the old fakephp's assumption that it could create a file per function. So we re-implement fakephp to avoid using the standard PCI hotplug API so that we can restore the old fakephp user interface. It puts entries in /sys/bus/pci/slots with the names of all PCI devices/functions, exactly symmetrical to what is shown in /sys/bus/pci/devices. Each slots/ entry has a "power" attribute, which works the same way as the fakephp driver's power attribute has worked. There are a few improvements over old fakephp, which couldn't handle PCI devices being added or removed via a means outside of fakephp's knowledge. If a device was added another way, old fakephp didn't notice and didn't create the fake slot for it. If a device was removed another way, old fakephp didn't delete the fake slot for it (and accessing the stale slot caused an oops). The new implementation overcomes these limitations. As a consequence, removing a bridge with other devices behind it now works as well, which is something else old fakephp couldn't do previously. This duplicates a tiny bit of the code in the PCI core that does this same function. Re-using that code ends up being more complex than duplicating it, and it makes code in the PCI core more ugly just to support this legacy fakephp interface compatibility layer. Reviewed-by: James Cameron <qz@hp.com> Signed-off-by: Trent Piepho <xyzzy@speakeasy.org> Signed-off-by: Alex Chiang <achiang@hp.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2009-03-20 20:56:46 +00:00
dev_warn(&pdev->dev, "Failed to created legacy fake slot\n");
return -EINVAL;
}
slot->dev = pci_dev_get(pdev);
list_add(&slot->list, &legacy_list);
return 0;
}
static int legacy_notify(struct notifier_block *nb,
unsigned long action, void *data)
{
struct pci_dev *pdev = to_pci_dev(data);
if (action == BUS_NOTIFY_ADD_DEVICE) {
legacy_add_slot(pdev);
} else if (action == BUS_NOTIFY_DEL_DEVICE) {
struct legacy_slot *slot;
list_for_each_entry(slot, &legacy_list, list)
if (slot->dev == pdev)
goto found;
dev_warn(&pdev->dev, "Missing legacy fake slot?");
return -ENODEV;
found:
kobject_del(&slot->kobj);
list_del(&slot->list);
kobject_put(&slot->kobj);
}
return 0;
}
static struct notifier_block legacy_notifier = {
.notifier_call = legacy_notify
};
static int __init init_legacy(void)
{
struct pci_dev *pdev = NULL;
/* Add existing devices */
for_each_pci_dev(pdev)
PCI Hotplug: restore fakephp interface with complete reimplementation A complete re-implementation of fakephp is necessary if it is to present its former interface (pre-2.6.27, when it broke). The reason is that PCI hotplug drivers call pci_hp_register(), which enforces the rule that only one /sys/bus/pci/slots/ file may be created per physical slot. The change breaks the old fakephp's assumption that it could create a file per function. So we re-implement fakephp to avoid using the standard PCI hotplug API so that we can restore the old fakephp user interface. It puts entries in /sys/bus/pci/slots with the names of all PCI devices/functions, exactly symmetrical to what is shown in /sys/bus/pci/devices. Each slots/ entry has a "power" attribute, which works the same way as the fakephp driver's power attribute has worked. There are a few improvements over old fakephp, which couldn't handle PCI devices being added or removed via a means outside of fakephp's knowledge. If a device was added another way, old fakephp didn't notice and didn't create the fake slot for it. If a device was removed another way, old fakephp didn't delete the fake slot for it (and accessing the stale slot caused an oops). The new implementation overcomes these limitations. As a consequence, removing a bridge with other devices behind it now works as well, which is something else old fakephp couldn't do previously. This duplicates a tiny bit of the code in the PCI core that does this same function. Re-using that code ends up being more complex than duplicating it, and it makes code in the PCI core more ugly just to support this legacy fakephp interface compatibility layer. Reviewed-by: James Cameron <qz@hp.com> Signed-off-by: Trent Piepho <xyzzy@speakeasy.org> Signed-off-by: Alex Chiang <achiang@hp.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2009-03-20 20:56:46 +00:00
legacy_add_slot(pdev);
/* Be alerted of any new ones */
bus_register_notifier(&pci_bus_type, &legacy_notifier);
return 0;
}
module_init(init_legacy);
static void __exit remove_legacy(void)
{
struct legacy_slot *slot, *tmp;
bus_unregister_notifier(&pci_bus_type, &legacy_notifier);
list_for_each_entry_safe(slot, tmp, &legacy_list, list) {
list_del(&slot->list);
kobject_del(&slot->kobj);
kobject_put(&slot->kobj);
}
}
module_exit(remove_legacy);
MODULE_AUTHOR("Trent Piepho <xyzzy@speakeasy.org>");
MODULE_DESCRIPTION("Legacy version of the fakephp interface");
MODULE_LICENSE("GPL");