| Message ID | 4002729.BbipMAJtM0@vostro.rjw.lan |
|---|---|
| State | Superseded |
| Headers | show |
On 12/10/2012 07:00 AM, Rafael J. Wysocki wrote: > From: Rafael J. Wysocki <rafael.j.wysocki@intel.com> > > Currently, as soon as an ACPI device node object (struct acpi_device) > is created, the driver core attempts to probe ACPI drivers against > it. That leads to some unpleasant side effects, like the fact that > the boot code path for ACPI namespace scanning is different from the > analogous hot-plug code path (during boot ACPI drivers are not > present when ACPI device node objects are registered, so they are > guaranteed not to be probed, which is not the case during hot-plug). > That, in turn, leads to unnecessary complications in the PCI > enumeration algorithm. > > Reduce the differences between the boot and hot-plug cases by > splitting the ACPI namespace scanning for devices into two passes, > such that struct acpi_device objects are registerd in the first > patch without probing ACPI drivers and the drivers are probed > against them directly in the second pass. This way ACPI drivers > can assume that all of the ACPI device node objects in the given > scope will be registered when their .add() routines run and the > hot-plug case becomes the same as the boot case from their > perspective. > > Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> > --- > drivers/acpi/scan.c | 96 +++++++++++++++++++++++++++++++++--------------- > include/acpi/acpi_bus.h | 1 > 2 files changed, 68 insertions(+), 29 deletions(-) > > Index: linux/include/acpi/acpi_bus.h > =================================================================== > --- linux.orig/include/acpi/acpi_bus.h > +++ linux/include/acpi/acpi_bus.h > @@ -98,6 +98,7 @@ typedef void (*acpi_op_notify) (struct a > struct acpi_bus_ops { > u32 acpi_op_add:1; > u32 acpi_op_start:1; > + u32 acpi_op_match:1; > }; > > struct acpi_device_ops { > Index: linux/drivers/acpi/scan.c > =================================================================== > --- linux.orig/drivers/acpi/scan.c > +++ linux/drivers/acpi/scan.c > @@ -494,7 +494,8 @@ static int acpi_bus_match(struct device > struct acpi_device *acpi_dev = to_acpi_device(dev); > struct acpi_driver *acpi_drv = to_acpi_driver(drv); > > - return !acpi_match_device_ids(acpi_dev, acpi_drv->ids); > + return acpi_dev->bus_ops.acpi_op_match > + && !acpi_match_device_ids(acpi_dev, acpi_drv->ids); > } Hi Rafael, PCI host bridge hotplug has the same requirement to separate device enumeration from device driver binding. And VFIO has a similar requirement too. Yinghai and I have implemented two different solutions for PCI host bridge hotplug but all rejected by Greg. So it would be great if we could promote a common mechanism to the device core to temporarily disable binding drivers to devices, which could used to support ACPI hotplug, PCI hotplug and VFIO. Regards! Gerry -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 12/10/2012 07:00 AM, Rafael J. Wysocki wrote: > From: Rafael J. Wysocki <rafael.j.wysocki@intel.com> > > Currently, as soon as an ACPI device node object (struct acpi_device) snip > @@ -1600,48 +1608,77 @@ static acpi_status acpi_bus_check_add(ac > * We may already have an acpi_device from a previous enumeration. If > * so, we needn't add it again, but we may still have to start it. > */ > - device = NULL; > acpi_bus_get_device(handle, &device); > if (ops->acpi_op_add && !device) { > - acpi_add_single_object(&device, handle, type, sta, ops); > - /* Is the device a known good platform device? */ > - if (device > - && !acpi_match_device_ids(device, acpi_platform_device_ids)) > - acpi_create_platform_device(device); > - } > + struct acpi_bus_ops add_ops = *ops; > > - if (!device) > - return AE_CTRL_DEPTH; > - > - if (ops->acpi_op_start && !(ops->acpi_op_add)) { > - status = acpi_start_single_object(device); > - if (ACPI_FAILURE(status)) > + add_ops.acpi_op_match = 0; > + acpi_add_single_object(&device, handle, type, sta, &add_ops); > + if (!device) > return AE_CTRL_DEPTH; > + > + device->bus_ops.acpi_op_match = 1; > } > > if (!*return_value) > *return_value = device; > + > return AE_OK; > } > > +static acpi_status acpi_bus_probe_start(acpi_handle handle, u32 lvl, > + void *context, void **not_used) > +{ > + struct acpi_bus_ops *ops = context; > + struct acpi_device *device; > + acpi_status status = AE_OK; > + > + if (acpi_bus_get_device(handle, &device)) > + return AE_CTRL_DEPTH; > + > + if (ops->acpi_op_add) { > + if (!acpi_match_device_ids(device, acpi_platform_device_ids)) { > + /* This is a known good platform device. */ > + acpi_create_platform_device(device); > + } else { > + int ret = device_attach(&device->dev); > + acpi_hot_add_bind(device); > + if (ret) > + status = AE_CTRL_DEPTH; > + } > + } else if (ops->acpi_op_start) { > + if (ACPI_FAILURE(acpi_start_single_object(device))) > + status = AE_CTRL_DEPTH; > + } > + return status; > +} > + > static int acpi_bus_scan(acpi_handle handle, struct acpi_bus_ops *ops, > struct acpi_device **child) > { > - acpi_status status; > void *device = NULL; > + acpi_status status; > + int ret = 0; > > status = acpi_bus_check_add(handle, 0, ops, &device); > - if (ACPI_SUCCESS(status)) > + if (ACPI_FAILURE(status)) { > + ret = -ENODEV; > + goto out; > + } > + > + acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX, > + acpi_bus_check_add, NULL, ops, &device); > + if (device) > acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX, > - acpi_bus_check_add, NULL, ops, &device); > + acpi_bus_probe_start, NULL, ops, NULL); Hi Rafael, Should we call acpi_bus_probe_start for the top device corresponding to "handle" too here? > + else > + ret = -ENODEV; > > + out: > if (child) > *child = device; > > - if (device) > - return 0; > - else > - return -ENODEV; > + return ret; > } > > /* > @@ -1752,6 +1789,7 @@ static int acpi_bus_scan_fixed(void) > memset(&ops, 0, sizeof(ops)); > ops.acpi_op_add = 1; > ops.acpi_op_start = 1; > + ops.acpi_op_match = 1; > > /* > * Enumerate all fixed-feature devices. > > -- > To unsubscribe from this list: send the line "unsubscribe linux-pci" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Thursday, December 13, 2012 12:38:01 AM Jiang Liu wrote: > On 12/10/2012 07:00 AM, Rafael J. Wysocki wrote: > > From: Rafael J. Wysocki <rafael.j.wysocki@intel.com> > > > > Currently, as soon as an ACPI device node object (struct acpi_device) > snip > > > @@ -1600,48 +1608,77 @@ static acpi_status acpi_bus_check_add(ac > > * We may already have an acpi_device from a previous enumeration. If > > * so, we needn't add it again, but we may still have to start it. > > */ > > - device = NULL; > > acpi_bus_get_device(handle, &device); > > if (ops->acpi_op_add && !device) { > > - acpi_add_single_object(&device, handle, type, sta, ops); > > - /* Is the device a known good platform device? */ > > - if (device > > - && !acpi_match_device_ids(device, acpi_platform_device_ids)) > > - acpi_create_platform_device(device); > > - } > > + struct acpi_bus_ops add_ops = *ops; > > > > - if (!device) > > - return AE_CTRL_DEPTH; > > - > > - if (ops->acpi_op_start && !(ops->acpi_op_add)) { > > - status = acpi_start_single_object(device); > > - if (ACPI_FAILURE(status)) > > + add_ops.acpi_op_match = 0; > > + acpi_add_single_object(&device, handle, type, sta, &add_ops); > > + if (!device) > > return AE_CTRL_DEPTH; > > + > > + device->bus_ops.acpi_op_match = 1; > > } > > > > if (!*return_value) > > *return_value = device; > > + > > return AE_OK; > > } > > > > +static acpi_status acpi_bus_probe_start(acpi_handle handle, u32 lvl, > > + void *context, void **not_used) > > +{ > > + struct acpi_bus_ops *ops = context; > > + struct acpi_device *device; > > + acpi_status status = AE_OK; > > + > > + if (acpi_bus_get_device(handle, &device)) > > + return AE_CTRL_DEPTH; > > + > > + if (ops->acpi_op_add) { > > + if (!acpi_match_device_ids(device, acpi_platform_device_ids)) { > > + /* This is a known good platform device. */ > > + acpi_create_platform_device(device); > > + } else { > > + int ret = device_attach(&device->dev); > > + acpi_hot_add_bind(device); > > + if (ret) > > + status = AE_CTRL_DEPTH; > > + } > > + } else if (ops->acpi_op_start) { > > + if (ACPI_FAILURE(acpi_start_single_object(device))) > > + status = AE_CTRL_DEPTH; > > + } > > + return status; > > +} > > + > > static int acpi_bus_scan(acpi_handle handle, struct acpi_bus_ops *ops, > > struct acpi_device **child) > > { > > - acpi_status status; > > void *device = NULL; > > + acpi_status status; > > + int ret = 0; > > > > status = acpi_bus_check_add(handle, 0, ops, &device); > > - if (ACPI_SUCCESS(status)) > > + if (ACPI_FAILURE(status)) { > > + ret = -ENODEV; > > + goto out; > > + } > > + > > + acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX, > > + acpi_bus_check_add, NULL, ops, &device); > > + if (device) > > acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX, > > - acpi_bus_check_add, NULL, ops, &device); > > + acpi_bus_probe_start, NULL, ops, NULL); > Hi Rafael, > Should we call acpi_bus_probe_start for the top device corresponding to > "handle" too here? Do you mean separately? I don't think so. It will be covered by the namespace walking, won't it? Rafael
On Wednesday, December 12, 2012 11:50:06 PM Jiang Liu wrote: > On 12/10/2012 07:00 AM, Rafael J. Wysocki wrote: > > From: Rafael J. Wysocki <rafael.j.wysocki@intel.com> > > > > Currently, as soon as an ACPI device node object (struct acpi_device) > > is created, the driver core attempts to probe ACPI drivers against > > it. That leads to some unpleasant side effects, like the fact that > > the boot code path for ACPI namespace scanning is different from the > > analogous hot-plug code path (during boot ACPI drivers are not > > present when ACPI device node objects are registered, so they are > > guaranteed not to be probed, which is not the case during hot-plug). > > That, in turn, leads to unnecessary complications in the PCI > > enumeration algorithm. > > > > Reduce the differences between the boot and hot-plug cases by > > splitting the ACPI namespace scanning for devices into two passes, > > such that struct acpi_device objects are registerd in the first > > patch without probing ACPI drivers and the drivers are probed > > against them directly in the second pass. This way ACPI drivers > > can assume that all of the ACPI device node objects in the given > > scope will be registered when their .add() routines run and the > > hot-plug case becomes the same as the boot case from their > > perspective. > > > > Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> > > --- > > drivers/acpi/scan.c | 96 +++++++++++++++++++++++++++++++++--------------- > > include/acpi/acpi_bus.h | 1 > > 2 files changed, 68 insertions(+), 29 deletions(-) > > > > Index: linux/include/acpi/acpi_bus.h > > =================================================================== > > --- linux.orig/include/acpi/acpi_bus.h > > +++ linux/include/acpi/acpi_bus.h > > @@ -98,6 +98,7 @@ typedef void (*acpi_op_notify) (struct a > > struct acpi_bus_ops { > > u32 acpi_op_add:1; > > u32 acpi_op_start:1; > > + u32 acpi_op_match:1; > > }; > > > > struct acpi_device_ops { > > Index: linux/drivers/acpi/scan.c > > =================================================================== > > --- linux.orig/drivers/acpi/scan.c > > +++ linux/drivers/acpi/scan.c > > @@ -494,7 +494,8 @@ static int acpi_bus_match(struct device > > struct acpi_device *acpi_dev = to_acpi_device(dev); > > struct acpi_driver *acpi_drv = to_acpi_driver(drv); > > > > - return !acpi_match_device_ids(acpi_dev, acpi_drv->ids); > > + return acpi_dev->bus_ops.acpi_op_match > > + && !acpi_match_device_ids(acpi_dev, acpi_drv->ids); > > } > Hi Rafael, > PCI host bridge hotplug has the same requirement to separate device > enumeration from device driver binding. And VFIO has a similar requirement too. > Yinghai and I have implemented two different solutions for PCI host bridge > hotplug but all rejected by Greg. So it would be great if we could promote > a common mechanism to the device core to temporarily disable binding drivers > to devices, which could used to support ACPI hotplug, PCI hotplug and VFIO. OK, but let's first have a good common use case, I think. I mean, let's implement it in each of these subsystems separately and then show that it leads to simpler code if we move it up to the driver core. Thanks, Rafael
On Sun, Dec 9, 2012 at 4:00 PM, Rafael J. Wysocki <rjw@sisk.pl> wrote: > From: Rafael J. Wysocki <rafael.j.wysocki@intel.com> > > Currently, as soon as an ACPI device node object (struct acpi_device) > is created, the driver core attempts to probe ACPI drivers against > it. That leads to some unpleasant side effects, like the fact that > the boot code path for ACPI namespace scanning is different from the > analogous hot-plug code path (during boot ACPI drivers are not > present when ACPI device node objects are registered, so they are > guaranteed not to be probed, which is not the case during hot-plug). > That, in turn, leads to unnecessary complications in the PCI > enumeration algorithm. Can you elaborate a bit on the complications in PCI enumeration? Hopefully this will lead to some simplification in PCI enumeration, but these patches don't go that far (yet). > Reduce the differences between the boot and hot-plug cases by > splitting the ACPI namespace scanning for devices into two passes, > such that struct acpi_device objects are registerd in the first > patch without probing ACPI drivers and the drivers are probed > against them directly in the second pass. This way ACPI drivers > can assume that all of the ACPI device node objects in the given > scope will be registered when their .add() routines run and the > hot-plug case becomes the same as the boot case from their > perspective. If I understand correctly, you're talking about a hierarchical topology where a device, e.g., a bridge, can have subordinate devices below it. In general terms, if a driver claims X, and the driver's add() method can assume that every device below X has already been registered, I guess that means any bridge drivers must be integrated into the core, so the core can enumerate things below the bridge without the driver's help. The PCI core effectively has the P2P bridge driver integrated into it, so that's the way it is already for PCI. I can imagine scenarios, e.g., NTBs, where it's not practical to integrate the bridge driver, so I'm not 100% comfortable with this assumption. But I admit that's a totally hypothetical situation, and there are lots of other obstacles to non-integrated bridge drivers, like the fact that we can't do dynamic resource assignment. s/registerd/registered/ above > Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> > --- > drivers/acpi/scan.c | 96 +++++++++++++++++++++++++++++++++--------------- > include/acpi/acpi_bus.h | 1 > 2 files changed, 68 insertions(+), 29 deletions(-) > > Index: linux/include/acpi/acpi_bus.h > =================================================================== > --- linux.orig/include/acpi/acpi_bus.h > +++ linux/include/acpi/acpi_bus.h > @@ -98,6 +98,7 @@ typedef void (*acpi_op_notify) (struct a > struct acpi_bus_ops { > u32 acpi_op_add:1; > u32 acpi_op_start:1; > + u32 acpi_op_match:1; > }; > > struct acpi_device_ops { > Index: linux/drivers/acpi/scan.c > =================================================================== > --- linux.orig/drivers/acpi/scan.c > +++ linux/drivers/acpi/scan.c > @@ -494,7 +494,8 @@ static int acpi_bus_match(struct device > struct acpi_device *acpi_dev = to_acpi_device(dev); > struct acpi_driver *acpi_drv = to_acpi_driver(drv); > > - return !acpi_match_device_ids(acpi_dev, acpi_drv->ids); > + return acpi_dev->bus_ops.acpi_op_match > + && !acpi_match_device_ids(acpi_dev, acpi_drv->ids); > } > > static int acpi_device_uevent(struct device *dev, struct kobj_uevent_env *env) > @@ -1418,6 +1419,17 @@ static int acpi_bus_remove(struct acpi_d > return 0; > } > > +/* > + * acpi_hot_add_bind - Bind _ADR-based devices on hot-add. > + * @device: ACPI device node to bind. > + */ > +static void acpi_hot_add_bind(struct acpi_device *device) > +{ > + if (device->flags.bus_address > + && device->parent && device->parent->ops.bind) > + device->parent->ops.bind(device); > +} > + > static int acpi_add_single_object(struct acpi_device **child, > acpi_handle handle, int type, > unsigned long long sta, > @@ -1490,13 +1502,8 @@ static int acpi_add_single_object(struct > > result = acpi_device_register(device); > > - /* > - * Bind _ADR-Based Devices when hot add > - */ > - if (device->flags.bus_address) { > - if (device->parent && device->parent->ops.bind) > - device->parent->ops.bind(device); > - } > + if (device->bus_ops.acpi_op_match) > + acpi_hot_add_bind(device); > > end: > if (!result) { > @@ -1522,6 +1529,7 @@ static void acpi_bus_add_power_resource( > struct acpi_bus_ops ops = { > .acpi_op_add = 1, > .acpi_op_start = 1, > + .acpi_op_match = 1, > }; > struct acpi_device *device = NULL; > > @@ -1574,9 +1582,9 @@ static acpi_status acpi_bus_check_add(ac > void *context, void **return_value) > { > struct acpi_bus_ops *ops = context; > + struct acpi_device *device = NULL; > int type; > unsigned long long sta; > - struct acpi_device *device; > acpi_status status; > int result; > > @@ -1600,48 +1608,77 @@ static acpi_status acpi_bus_check_add(ac > * We may already have an acpi_device from a previous enumeration. If > * so, we needn't add it again, but we may still have to start it. > */ > - device = NULL; > acpi_bus_get_device(handle, &device); > if (ops->acpi_op_add && !device) { > - acpi_add_single_object(&device, handle, type, sta, ops); > - /* Is the device a known good platform device? */ > - if (device > - && !acpi_match_device_ids(device, acpi_platform_device_ids)) > - acpi_create_platform_device(device); > - } > + struct acpi_bus_ops add_ops = *ops; > > - if (!device) > - return AE_CTRL_DEPTH; > - > - if (ops->acpi_op_start && !(ops->acpi_op_add)) { > - status = acpi_start_single_object(device); > - if (ACPI_FAILURE(status)) > + add_ops.acpi_op_match = 0; > + acpi_add_single_object(&device, handle, type, sta, &add_ops); > + if (!device) > return AE_CTRL_DEPTH; > + > + device->bus_ops.acpi_op_match = 1; > } > > if (!*return_value) > *return_value = device; > + > return AE_OK; > } > > +static acpi_status acpi_bus_probe_start(acpi_handle handle, u32 lvl, > + void *context, void **not_used) > +{ > + struct acpi_bus_ops *ops = context; > + struct acpi_device *device; > + acpi_status status = AE_OK; > + > + if (acpi_bus_get_device(handle, &device)) > + return AE_CTRL_DEPTH; > + > + if (ops->acpi_op_add) { > + if (!acpi_match_device_ids(device, acpi_platform_device_ids)) { > + /* This is a known good platform device. */ > + acpi_create_platform_device(device); > + } else { > + int ret = device_attach(&device->dev); > + acpi_hot_add_bind(device); > + if (ret) > + status = AE_CTRL_DEPTH; > + } > + } else if (ops->acpi_op_start) { > + if (ACPI_FAILURE(acpi_start_single_object(device))) > + status = AE_CTRL_DEPTH; > + } > + return status; > +} > + > static int acpi_bus_scan(acpi_handle handle, struct acpi_bus_ops *ops, > struct acpi_device **child) > { > - acpi_status status; > void *device = NULL; > + acpi_status status; > + int ret = 0; > > status = acpi_bus_check_add(handle, 0, ops, &device); > - if (ACPI_SUCCESS(status)) > + if (ACPI_FAILURE(status)) { > + ret = -ENODEV; > + goto out; > + } > + > + acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX, > + acpi_bus_check_add, NULL, ops, &device); > + if (device) > acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX, > - acpi_bus_check_add, NULL, ops, &device); > + acpi_bus_probe_start, NULL, ops, NULL); > + else > + ret = -ENODEV; > > + out: > if (child) > *child = device; > > - if (device) > - return 0; > - else > - return -ENODEV; > + return ret; > } > > /* > @@ -1752,6 +1789,7 @@ static int acpi_bus_scan_fixed(void) > memset(&ops, 0, sizeof(ops)); > ops.acpi_op_add = 1; > ops.acpi_op_start = 1; > + ops.acpi_op_match = 1; > > /* > * Enumerate all fixed-feature devices. > -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Wednesday, December 12, 2012 06:00:03 PM Bjorn Helgaas wrote: > On Sun, Dec 9, 2012 at 4:00 PM, Rafael J. Wysocki <rjw@sisk.pl> wrote: > > From: Rafael J. Wysocki <rafael.j.wysocki@intel.com> > > > > Currently, as soon as an ACPI device node object (struct acpi_device) > > is created, the driver core attempts to probe ACPI drivers against > > it. That leads to some unpleasant side effects, like the fact that > > the boot code path for ACPI namespace scanning is different from the > > analogous hot-plug code path (during boot ACPI drivers are not > > present when ACPI device node objects are registered, so they are > > guaranteed not to be probed, which is not the case during hot-plug). > > That, in turn, leads to unnecessary complications in the PCI > > enumeration algorithm. > > Can you elaborate a bit on the complications in PCI enumeration? > Hopefully this will lead to some simplification in PCI enumeration, > but these patches don't go that far (yet). For example, in the hotplug case it is not guaranteed that companion struct acpi_device objects have been created already when struct pci_dev objects are created during acpi_pci_root_add(). This forces us to use acpi_get_pci_dev() in acpi_pci_bind(), which we could avoid otherwise. Moreover, if we knew that the companion struct acpi_device objects existed as soon as in pci_scan_device(), we could just populate the ACPI handle of the struct pci_dev in there and that would allow acpi_platform_notify() later on to skip the bus browsing (due to recent changes just merged in). I suppose we could even get rid of acpi_pci_bind()/acpi_pci_unbind() by integrating that code directly into the initialization/removal code paths. > > Reduce the differences between the boot and hot-plug cases by > > splitting the ACPI namespace scanning for devices into two passes, > > such that struct acpi_device objects are registerd in the first > > patch without probing ACPI drivers and the drivers are probed > > against them directly in the second pass. This way ACPI drivers > > can assume that all of the ACPI device node objects in the given > > scope will be registered when their .add() routines run and the > > hot-plug case becomes the same as the boot case from their > > perspective. > > If I understand correctly, you're talking about a hierarchical > topology where a device, e.g., a bridge, can have subordinate devices > below it. > > In general terms, if a driver claims X, and the driver's add() method > can assume that every device below X has already been registered, I > guess that means any bridge drivers must be integrated into the core, > so the core can enumerate things below the bridge without the driver's > help. Well, I don't quite understand. Do you have an example? We're registering only struct acpi_device things kind of in advance here. I would assume that device drivers would operate on device structures of other types (like struct pci_dev) and those struct acpi_device objects would only be companions of the "physical" device nodes. IOW what we do here is to extract some information from ACPI tables and put it into a number of objects in the device hierarchy (the fact that they are in the device hierarchy allows us to export some of their properties via sysfs easily), but that's about it. How buses/drivers use that information is up to them. And by the way, I think that binding drivers to struct acpi_device objects directly is too much of a shortcut and it leads to more problems than it solves. I'd like to get rid of that eventually. > The PCI core effectively has the P2P bridge driver integrated > into it, so that's the way it is already for PCI. I can imagine > scenarios, e.g., NTBs, where it's not practical to integrate the > bridge driver, so I'm not 100% comfortable with this assumption. But > I admit that's a totally hypothetical situation, and there are lots of > other obstacles to non-integrated bridge drivers, like the fact that > we can't do dynamic resource assignment. Well, precisely. :-) > s/registerd/registered/ above Yup, thanks! Thanks a lot for having a look. :-) Rafael > > Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> > > --- > > drivers/acpi/scan.c | 96 +++++++++++++++++++++++++++++++++--------------- > > include/acpi/acpi_bus.h | 1 > > 2 files changed, 68 insertions(+), 29 deletions(-) > > > > Index: linux/include/acpi/acpi_bus.h > > =================================================================== > > --- linux.orig/include/acpi/acpi_bus.h > > +++ linux/include/acpi/acpi_bus.h > > @@ -98,6 +98,7 @@ typedef void (*acpi_op_notify) (struct a > > struct acpi_bus_ops { > > u32 acpi_op_add:1; > > u32 acpi_op_start:1; > > + u32 acpi_op_match:1; > > }; > > > > struct acpi_device_ops { > > Index: linux/drivers/acpi/scan.c > > =================================================================== > > --- linux.orig/drivers/acpi/scan.c > > +++ linux/drivers/acpi/scan.c > > @@ -494,7 +494,8 @@ static int acpi_bus_match(struct device > > struct acpi_device *acpi_dev = to_acpi_device(dev); > > struct acpi_driver *acpi_drv = to_acpi_driver(drv); > > > > - return !acpi_match_device_ids(acpi_dev, acpi_drv->ids); > > + return acpi_dev->bus_ops.acpi_op_match > > + && !acpi_match_device_ids(acpi_dev, acpi_drv->ids); > > } > > > > static int acpi_device_uevent(struct device *dev, struct kobj_uevent_env *env) > > @@ -1418,6 +1419,17 @@ static int acpi_bus_remove(struct acpi_d > > return 0; > > } > > > > +/* > > + * acpi_hot_add_bind - Bind _ADR-based devices on hot-add. > > + * @device: ACPI device node to bind. > > + */ > > +static void acpi_hot_add_bind(struct acpi_device *device) > > +{ > > + if (device->flags.bus_address > > + && device->parent && device->parent->ops.bind) > > + device->parent->ops.bind(device); > > +} > > + > > static int acpi_add_single_object(struct acpi_device **child, > > acpi_handle handle, int type, > > unsigned long long sta, > > @@ -1490,13 +1502,8 @@ static int acpi_add_single_object(struct > > > > result = acpi_device_register(device); > > > > - /* > > - * Bind _ADR-Based Devices when hot add > > - */ > > - if (device->flags.bus_address) { > > - if (device->parent && device->parent->ops.bind) > > - device->parent->ops.bind(device); > > - } > > + if (device->bus_ops.acpi_op_match) > > + acpi_hot_add_bind(device); > > > > end: > > if (!result) { > > @@ -1522,6 +1529,7 @@ static void acpi_bus_add_power_resource( > > struct acpi_bus_ops ops = { > > .acpi_op_add = 1, > > .acpi_op_start = 1, > > + .acpi_op_match = 1, > > }; > > struct acpi_device *device = NULL; > > > > @@ -1574,9 +1582,9 @@ static acpi_status acpi_bus_check_add(ac > > void *context, void **return_value) > > { > > struct acpi_bus_ops *ops = context; > > + struct acpi_device *device = NULL; > > int type; > > unsigned long long sta; > > - struct acpi_device *device; > > acpi_status status; > > int result; > > > > @@ -1600,48 +1608,77 @@ static acpi_status acpi_bus_check_add(ac > > * We may already have an acpi_device from a previous enumeration. If > > * so, we needn't add it again, but we may still have to start it. > > */ > > - device = NULL; > > acpi_bus_get_device(handle, &device); > > if (ops->acpi_op_add && !device) { > > - acpi_add_single_object(&device, handle, type, sta, ops); > > - /* Is the device a known good platform device? */ > > - if (device > > - && !acpi_match_device_ids(device, acpi_platform_device_ids)) > > - acpi_create_platform_device(device); > > - } > > + struct acpi_bus_ops add_ops = *ops; > > > > - if (!device) > > - return AE_CTRL_DEPTH; > > - > > - if (ops->acpi_op_start && !(ops->acpi_op_add)) { > > - status = acpi_start_single_object(device); > > - if (ACPI_FAILURE(status)) > > + add_ops.acpi_op_match = 0; > > + acpi_add_single_object(&device, handle, type, sta, &add_ops); > > + if (!device) > > return AE_CTRL_DEPTH; > > + > > + device->bus_ops.acpi_op_match = 1; > > } > > > > if (!*return_value) > > *return_value = device; > > + > > return AE_OK; > > } > > > > +static acpi_status acpi_bus_probe_start(acpi_handle handle, u32 lvl, > > + void *context, void **not_used) > > +{ > > + struct acpi_bus_ops *ops = context; > > + struct acpi_device *device; > > + acpi_status status = AE_OK; > > + > > + if (acpi_bus_get_device(handle, &device)) > > + return AE_CTRL_DEPTH; > > + > > + if (ops->acpi_op_add) { > > + if (!acpi_match_device_ids(device, acpi_platform_device_ids)) { > > + /* This is a known good platform device. */ > > + acpi_create_platform_device(device); > > + } else { > > + int ret = device_attach(&device->dev); > > + acpi_hot_add_bind(device); > > + if (ret) > > + status = AE_CTRL_DEPTH; > > + } > > + } else if (ops->acpi_op_start) { > > + if (ACPI_FAILURE(acpi_start_single_object(device))) > > + status = AE_CTRL_DEPTH; > > + } > > + return status; > > +} > > + > > static int acpi_bus_scan(acpi_handle handle, struct acpi_bus_ops *ops, > > struct acpi_device **child) > > { > > - acpi_status status; > > void *device = NULL; > > + acpi_status status; > > + int ret = 0; > > > > status = acpi_bus_check_add(handle, 0, ops, &device); > > - if (ACPI_SUCCESS(status)) > > + if (ACPI_FAILURE(status)) { > > + ret = -ENODEV; > > + goto out; > > + } > > + > > + acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX, > > + acpi_bus_check_add, NULL, ops, &device); > > + if (device) > > acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX, > > - acpi_bus_check_add, NULL, ops, &device); > > + acpi_bus_probe_start, NULL, ops, NULL); > > + else > > + ret = -ENODEV; > > > > + out: > > if (child) > > *child = device; > > > > - if (device) > > - return 0; > > - else > > - return -ENODEV; > > + return ret; > > } > > > > /* > > @@ -1752,6 +1789,7 @@ static int acpi_bus_scan_fixed(void) > > memset(&ops, 0, sizeof(ops)); > > ops.acpi_op_add = 1; > > ops.acpi_op_start = 1; > > + ops.acpi_op_match = 1; > > > > /* > > * Enumerate all fixed-feature devices. > >
On 12/13/2012 06:32 AM, Rafael J. Wysocki wrote: > On Thursday, December 13, 2012 12:38:01 AM Jiang Liu wrote: >> On 12/10/2012 07:00 AM, Rafael J. Wysocki wrote: >>> From: Rafael J. Wysocki <rafael.j.wysocki@intel.com> >>> >>> Currently, as soon as an ACPI device node object (struct acpi_device) >> snip >> >>> @@ -1600,48 +1608,77 @@ static acpi_status acpi_bus_check_add(ac >>> * We may already have an acpi_device from a previous enumeration. If >>> * so, we needn't add it again, but we may still have to start it. >>> */ >>> - device = NULL; >>> acpi_bus_get_device(handle, &device); >>> if (ops->acpi_op_add && !device) { >>> - acpi_add_single_object(&device, handle, type, sta, ops); >>> - /* Is the device a known good platform device? */ >>> - if (device >>> - && !acpi_match_device_ids(device, acpi_platform_device_ids)) >>> - acpi_create_platform_device(device); >>> - } >>> + struct acpi_bus_ops add_ops = *ops; >>> >>> - if (!device) >>> - return AE_CTRL_DEPTH; >>> - >>> - if (ops->acpi_op_start && !(ops->acpi_op_add)) { >>> - status = acpi_start_single_object(device); >>> - if (ACPI_FAILURE(status)) >>> + add_ops.acpi_op_match = 0; >>> + acpi_add_single_object(&device, handle, type, sta, &add_ops); >>> + if (!device) >>> return AE_CTRL_DEPTH; >>> + >>> + device->bus_ops.acpi_op_match = 1; >>> } >>> >>> if (!*return_value) >>> *return_value = device; >>> + >>> return AE_OK; >>> } >>> >>> +static acpi_status acpi_bus_probe_start(acpi_handle handle, u32 lvl, >>> + void *context, void **not_used) >>> +{ >>> + struct acpi_bus_ops *ops = context; >>> + struct acpi_device *device; >>> + acpi_status status = AE_OK; >>> + >>> + if (acpi_bus_get_device(handle, &device)) >>> + return AE_CTRL_DEPTH; >>> + >>> + if (ops->acpi_op_add) { >>> + if (!acpi_match_device_ids(device, acpi_platform_device_ids)) { >>> + /* This is a known good platform device. */ >>> + acpi_create_platform_device(device); >>> + } else { >>> + int ret = device_attach(&device->dev); >>> + acpi_hot_add_bind(device); >>> + if (ret) >>> + status = AE_CTRL_DEPTH; >>> + } >>> + } else if (ops->acpi_op_start) { >>> + if (ACPI_FAILURE(acpi_start_single_object(device))) >>> + status = AE_CTRL_DEPTH; >>> + } >>> + return status; >>> +} >>> + >>> static int acpi_bus_scan(acpi_handle handle, struct acpi_bus_ops *ops, >>> struct acpi_device **child) >>> { >>> - acpi_status status; >>> void *device = NULL; >>> + acpi_status status; >>> + int ret = 0; >>> >>> status = acpi_bus_check_add(handle, 0, ops, &device); >>> - if (ACPI_SUCCESS(status)) >>> + if (ACPI_FAILURE(status)) { >>> + ret = -ENODEV; >>> + goto out; >>> + } >>> + >>> + acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX, >>> + acpi_bus_check_add, NULL, ops, &device); >>> + if (device) >>> acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX, >>> - acpi_bus_check_add, NULL, ops, &device); >>> + acpi_bus_probe_start, NULL, ops, NULL); >> Hi Rafael, >> Should we call acpi_bus_probe_start for the top device corresponding to >> "handle" too here? > > Do you mean separately? I don't think so. It will be covered by the namespace > walking, won't it? Hi Rafael, According to test results from Yijing, we do need to call acpi_bus_probe_start for the top device corresponding to "handle". Comments for acpi_walk_namespace says: /******************************************************************************* * * FUNCTION: acpi_walk_namespace * * DESCRIPTION: Performs a modified depth-first walk of the namespace tree, * starting (and ending) at the object specified by start_handle. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ * The callback function is called whenever an object that matches * the type parameter is found. If the callback function returns * a non-zero value, the search is terminated immediately and this * value is returned to the caller. * * The point of this procedure is to provide a generic namespace * a non-zero value, the search is terminated immediately and this * value is returned to the caller. * * The point of this procedure is to provide a generic namespace * walk routine that can be called from multiple places to * provide multiple services; the callback function(s) can be * tailored to each task, whether it is a print function, * a compare function, etc. * ******************************************************************************/ But acpi_ns_walk_namespace() doesn't really call the pre_order_visit and post_order_visit for the start_handle. That means acpi_walk_namespace won't call the callback for the top handle. acpi_ns_walk_namespace(acpi_object_type type, acpi_handle start_node, u32 max_depth, u32 flags, acpi_walk_callback pre_order_visit, acpi_walk_callback post_order_visit, void *context, void **return_value) { ......................................... parent_node = start_node; child_node = acpi_ns_get_next_node(parent_node, NULL); child_type = ACPI_TYPE_ANY; level = 1; /* * Traverse the tree of nodes until we bubble back up to where we * started. When Level is zero, the loop is done because we have * bubbled up to (and passed) the original parent handle (start_entry) */ while (level > 0 && child_node) { ........................................... } > > Rafael > > -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Thursday, December 13, 2012 09:05:35 PM Jiang Liu wrote: > On 12/13/2012 06:32 AM, Rafael J. Wysocki wrote: > > On Thursday, December 13, 2012 12:38:01 AM Jiang Liu wrote: > >> On 12/10/2012 07:00 AM, Rafael J. Wysocki wrote: > >>> From: Rafael J. Wysocki <rafael.j.wysocki@intel.com> > >>> > >>> Currently, as soon as an ACPI device node object (struct acpi_device) > >> snip > >> > >>> @@ -1600,48 +1608,77 @@ static acpi_status acpi_bus_check_add(ac > >>> * We may already have an acpi_device from a previous enumeration. If > >>> * so, we needn't add it again, but we may still have to start it. > >>> */ > >>> - device = NULL; > >>> acpi_bus_get_device(handle, &device); > >>> if (ops->acpi_op_add && !device) { > >>> - acpi_add_single_object(&device, handle, type, sta, ops); > >>> - /* Is the device a known good platform device? */ > >>> - if (device > >>> - && !acpi_match_device_ids(device, acpi_platform_device_ids)) > >>> - acpi_create_platform_device(device); > >>> - } > >>> + struct acpi_bus_ops add_ops = *ops; > >>> > >>> - if (!device) > >>> - return AE_CTRL_DEPTH; > >>> - > >>> - if (ops->acpi_op_start && !(ops->acpi_op_add)) { > >>> - status = acpi_start_single_object(device); > >>> - if (ACPI_FAILURE(status)) > >>> + add_ops.acpi_op_match = 0; > >>> + acpi_add_single_object(&device, handle, type, sta, &add_ops); > >>> + if (!device) > >>> return AE_CTRL_DEPTH; > >>> + > >>> + device->bus_ops.acpi_op_match = 1; > >>> } > >>> > >>> if (!*return_value) > >>> *return_value = device; > >>> + > >>> return AE_OK; > >>> } > >>> > >>> +static acpi_status acpi_bus_probe_start(acpi_handle handle, u32 lvl, > >>> + void *context, void **not_used) > >>> +{ > >>> + struct acpi_bus_ops *ops = context; > >>> + struct acpi_device *device; > >>> + acpi_status status = AE_OK; > >>> + > >>> + if (acpi_bus_get_device(handle, &device)) > >>> + return AE_CTRL_DEPTH; > >>> + > >>> + if (ops->acpi_op_add) { > >>> + if (!acpi_match_device_ids(device, acpi_platform_device_ids)) { > >>> + /* This is a known good platform device. */ > >>> + acpi_create_platform_device(device); > >>> + } else { > >>> + int ret = device_attach(&device->dev); > >>> + acpi_hot_add_bind(device); > >>> + if (ret) > >>> + status = AE_CTRL_DEPTH; > >>> + } > >>> + } else if (ops->acpi_op_start) { > >>> + if (ACPI_FAILURE(acpi_start_single_object(device))) > >>> + status = AE_CTRL_DEPTH; > >>> + } > >>> + return status; > >>> +} > >>> + > >>> static int acpi_bus_scan(acpi_handle handle, struct acpi_bus_ops *ops, > >>> struct acpi_device **child) > >>> { > >>> - acpi_status status; > >>> void *device = NULL; > >>> + acpi_status status; > >>> + int ret = 0; > >>> > >>> status = acpi_bus_check_add(handle, 0, ops, &device); > >>> - if (ACPI_SUCCESS(status)) > >>> + if (ACPI_FAILURE(status)) { > >>> + ret = -ENODEV; > >>> + goto out; > >>> + } > >>> + > >>> + acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX, > >>> + acpi_bus_check_add, NULL, ops, &device); > >>> + if (device) > >>> acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX, > >>> - acpi_bus_check_add, NULL, ops, &device); > >>> + acpi_bus_probe_start, NULL, ops, NULL); > >> Hi Rafael, > >> Should we call acpi_bus_probe_start for the top device corresponding to > >> "handle" too here? > > > > Do you mean separately? I don't think so. It will be covered by the namespace > > walking, won't it? > Hi Rafael, > According to test results from Yijing, we do need to call acpi_bus_probe_start > for the top device corresponding to "handle". > Comments for acpi_walk_namespace says: > /******************************************************************************* > * > * FUNCTION: acpi_walk_namespace > * > * DESCRIPTION: Performs a modified depth-first walk of the namespace tree, > * starting (and ending) at the object specified by start_handle. > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > * The callback function is called whenever an object that matches > * the type parameter is found. If the callback function returns > * a non-zero value, the search is terminated immediately and this > * value is returned to the caller. > * > * The point of this procedure is to provide a generic namespace > * a non-zero value, the search is terminated immediately and this > * value is returned to the caller. > * > * The point of this procedure is to provide a generic namespace > * walk routine that can be called from multiple places to > * provide multiple services; the callback function(s) can be > * tailored to each task, whether it is a print function, > * a compare function, etc. > * > ******************************************************************************/ > > But acpi_ns_walk_namespace() doesn't really call the pre_order_visit and post_order_visit > for the start_handle. That means acpi_walk_namespace won't call the callback for the top > handle. You are right. I'll fix that and send updated series. It looks like Bjorn wants me to rework the changelogs anyway. :-) Thanks, Rafael
Index: linux/include/acpi/acpi_bus.h =================================================================== --- linux.orig/include/acpi/acpi_bus.h +++ linux/include/acpi/acpi_bus.h @@ -98,6 +98,7 @@ typedef void (*acpi_op_notify) (struct a struct acpi_bus_ops { u32 acpi_op_add:1; u32 acpi_op_start:1; + u32 acpi_op_match:1; }; struct acpi_device_ops { Index: linux/drivers/acpi/scan.c =================================================================== --- linux.orig/drivers/acpi/scan.c +++ linux/drivers/acpi/scan.c @@ -494,7 +494,8 @@ static int acpi_bus_match(struct device struct acpi_device *acpi_dev = to_acpi_device(dev); struct acpi_driver *acpi_drv = to_acpi_driver(drv); - return !acpi_match_device_ids(acpi_dev, acpi_drv->ids); + return acpi_dev->bus_ops.acpi_op_match + && !acpi_match_device_ids(acpi_dev, acpi_drv->ids); } static int acpi_device_uevent(struct device *dev, struct kobj_uevent_env *env) @@ -1418,6 +1419,17 @@ static int acpi_bus_remove(struct acpi_d return 0; } +/* + * acpi_hot_add_bind - Bind _ADR-based devices on hot-add. + * @device: ACPI device node to bind. + */ +static void acpi_hot_add_bind(struct acpi_device *device) +{ + if (device->flags.bus_address + && device->parent && device->parent->ops.bind) + device->parent->ops.bind(device); +} + static int acpi_add_single_object(struct acpi_device **child, acpi_handle handle, int type, unsigned long long sta, @@ -1490,13 +1502,8 @@ static int acpi_add_single_object(struct result = acpi_device_register(device); - /* - * Bind _ADR-Based Devices when hot add - */ - if (device->flags.bus_address) { - if (device->parent && device->parent->ops.bind) - device->parent->ops.bind(device); - } + if (device->bus_ops.acpi_op_match) + acpi_hot_add_bind(device); end: if (!result) { @@ -1522,6 +1529,7 @@ static void acpi_bus_add_power_resource( struct acpi_bus_ops ops = { .acpi_op_add = 1, .acpi_op_start = 1, + .acpi_op_match = 1, }; struct acpi_device *device = NULL; @@ -1574,9 +1582,9 @@ static acpi_status acpi_bus_check_add(ac void *context, void **return_value) { struct acpi_bus_ops *ops = context; + struct acpi_device *device = NULL; int type; unsigned long long sta; - struct acpi_device *device; acpi_status status; int result; @@ -1600,48 +1608,77 @@ static acpi_status acpi_bus_check_add(ac * We may already have an acpi_device from a previous enumeration. If * so, we needn't add it again, but we may still have to start it. */ - device = NULL; acpi_bus_get_device(handle, &device); if (ops->acpi_op_add && !device) { - acpi_add_single_object(&device, handle, type, sta, ops); - /* Is the device a known good platform device? */ - if (device - && !acpi_match_device_ids(device, acpi_platform_device_ids)) - acpi_create_platform_device(device); - } + struct acpi_bus_ops add_ops = *ops; - if (!device) - return AE_CTRL_DEPTH; - - if (ops->acpi_op_start && !(ops->acpi_op_add)) { - status = acpi_start_single_object(device); - if (ACPI_FAILURE(status)) + add_ops.acpi_op_match = 0; + acpi_add_single_object(&device, handle, type, sta, &add_ops); + if (!device) return AE_CTRL_DEPTH; + + device->bus_ops.acpi_op_match = 1; } if (!*return_value) *return_value = device; + return AE_OK; } +static acpi_status acpi_bus_probe_start(acpi_handle handle, u32 lvl, + void *context, void **not_used) +{ + struct acpi_bus_ops *ops = context; + struct acpi_device *device; + acpi_status status = AE_OK; + + if (acpi_bus_get_device(handle, &device)) + return AE_CTRL_DEPTH; + + if (ops->acpi_op_add) { + if (!acpi_match_device_ids(device, acpi_platform_device_ids)) { + /* This is a known good platform device. */ + acpi_create_platform_device(device); + } else { + int ret = device_attach(&device->dev); + acpi_hot_add_bind(device); + if (ret) + status = AE_CTRL_DEPTH; + } + } else if (ops->acpi_op_start) { + if (ACPI_FAILURE(acpi_start_single_object(device))) + status = AE_CTRL_DEPTH; + } + return status; +} + static int acpi_bus_scan(acpi_handle handle, struct acpi_bus_ops *ops, struct acpi_device **child) { - acpi_status status; void *device = NULL; + acpi_status status; + int ret = 0; status = acpi_bus_check_add(handle, 0, ops, &device); - if (ACPI_SUCCESS(status)) + if (ACPI_FAILURE(status)) { + ret = -ENODEV; + goto out; + } + + acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX, + acpi_bus_check_add, NULL, ops, &device); + if (device) acpi_walk_namespace(ACPI_TYPE_ANY, handle, ACPI_UINT32_MAX, - acpi_bus_check_add, NULL, ops, &device); + acpi_bus_probe_start, NULL, ops, NULL); + else + ret = -ENODEV; + out: if (child) *child = device; - if (device) - return 0; - else - return -ENODEV; + return ret; } /* @@ -1752,6 +1789,7 @@ static int acpi_bus_scan_fixed(void) memset(&ops, 0, sizeof(ops)); ops.acpi_op_add = 1; ops.acpi_op_start = 1; + ops.acpi_op_match = 1; /* * Enumerate all fixed-feature devices.