| Message ID | 20240528091144.112829-2-shayd@nvidia.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | Introduce auxiliary bus IRQs sysfs | expand |
On 5/28/24 11:11, Shay Drory wrote: > Some PCI subfunctions (SF) are anchored on the auxiliary bus. PCI > physical and virtual functions are anchored on the PCI bus. The irq > information of each such function is visible to users via sysfs > directory "msi_irqs" containing file for each irq entry. However, for > PCI SFs such information is unavailable. Due to this users have no > visibility on IRQs used by the SFs. > Secondly, an SF can be multi function device supporting rdma, netdevice > and more. Without irq information at the bus level, the user is unable > to view or use the affinity of the SF IRQs. > > Hence to match to the equivalent PCI PFs and VFs, add "irqs" directory, > for supporting auxiliary devices, containing file for each irq entry. > > Additionally, the PCI SFs sometimes share the IRQs with peer SFs. This > information is also not available to the users. To overcome this > limitation, each irq sysfs entry shows if irq is exclusive or shared. > > For example: > $ ls /sys/bus/auxiliary/devices/mlx5_core.sf.1/irqs/ > 50 51 52 53 54 55 56 57 58 > $ cat /sys/bus/auxiliary/devices/mlx5_core.sf.1/irqs/52 > exclusive > > Reviewed-by: Parav Pandit <parav@nvidia.com> > Signed-off-by: Shay Drory <shayd@nvidia.com> > > --- > v4-v5: > - restore global mutex and replace refcount_t with simple integer (Greg) > v3->4: > - remove global mutex (Przemek) > v2->v3: > - fix function declaration in case SYSFS isn't defined > v1->v2: > - move #ifdefs from drivers/base/auxiliary.c to > include/linux/auxiliary_bus.h (Greg) > - use EXPORT_SYMBOL_GPL instead of EXPORT_SYMBOL (Greg) > - Fix kzalloc(ref) to kzalloc(*ref) (Simon) > - Add return description in auxiliary_device_sysfs_irq_add() kdoc (Simon) > - Fix auxiliary_irq_mode_show doc (kernel test boot) > --- > Documentation/ABI/testing/sysfs-bus-auxiliary | 14 ++ > drivers/base/auxiliary.c | 165 +++++++++++++++++- > include/linux/auxiliary_bus.h | 24 ++- > 3 files changed, 200 insertions(+), 3 deletions(-) > create mode 100644 Documentation/ABI/testing/sysfs-bus-auxiliary > > diff --git a/Documentation/ABI/testing/sysfs-bus-auxiliary b/Documentation/ABI/testing/sysfs-bus-auxiliary > new file mode 100644 > index 000000000000..3b8299d49d9e > --- /dev/null > +++ b/Documentation/ABI/testing/sysfs-bus-auxiliary > @@ -0,0 +1,14 @@ > +What: /sys/bus/auxiliary/devices/.../irqs/ > +Date: April, 2024 > +Contact: Shay Drory <shayd@nvidia.com> > +Description: > + The /sys/devices/.../irqs directory contains a variable set of > + files, with each file is named as irq number similar to PCI PF > + or VF's irq number located in msi_irqs directory. > + > +What: /sys/bus/auxiliary/devices/.../irqs/<N> > +Date: April, 2024 > +Contact: Shay Drory <shayd@nvidia.com> > +Description: > + auxiliary devices can share IRQs. This attribute indicates if > + the irq is shared with other SFs or exclusively used by the SF. > diff --git a/drivers/base/auxiliary.c b/drivers/base/auxiliary.c > index d3a2c40c2f12..579d755dcbee 100644 > --- a/drivers/base/auxiliary.c > +++ b/drivers/base/auxiliary.c > @@ -158,6 +158,163 @@ > * }; > */ > > +#ifdef CONFIG_SYSFS > +/* Xarray of irqs to determine if irq is exclusive or shared. */ > +static DEFINE_XARRAY(irqs); > +/* Protects insertions into the irqs xarray. */ > +static DEFINE_MUTEX(irqs_lock); > + > +struct auxiliary_irq_info { > + struct device_attribute sysfs_attr; > + int irq; > +}; > + > +static struct attribute *auxiliary_irq_attrs[] = { > + NULL > +}; > + > +static const struct attribute_group auxiliary_irqs_group = { > + .name = "irqs", > + .attrs = auxiliary_irq_attrs, > +}; > + > +static const struct attribute_group *auxiliary_irqs_groups[] = { > + &auxiliary_irqs_group, > + NULL > +}; > + > +/* Auxiliary devices can share IRQs. Expose to user whether the provided IRQ is > + * shared or exclusive. > + */ > +static ssize_t auxiliary_irq_mode_show(struct device *dev, > + struct device_attribute *attr, char *buf) > +{ > + struct auxiliary_irq_info *info = > + container_of(attr, struct auxiliary_irq_info, sysfs_attr); > + int ref = xa_to_value(xa_load(&irqs, info->irq)); just a note that you forgot to take the global lock here > + > + if (!ref) > + return -ENOENT; > + if (ref > 1) > + return sysfs_emit(buf, "%s\n", "shared"); > + else > + return sysfs_emit(buf, "%s\n", "exclusive"); > +} > + > +static void auxiliary_irq_destroy(int irq) > +{ > + int ref; > + > + mutex_lock(&irqs_lock); > + ref = xa_to_value(xa_load(&irqs, irq)); > + if (!(--ref)) > + xa_erase(&irqs, irq); Global lock makes it indeed simpler to support xa_erase()-on-zero. There are simple solutions without erasing zero elements (you could have non-allocating store), but let's say we are leaving "the simplest" room then :) > + else > + xa_store(&irqs, irq, xa_mk_value(ref), GFP_KERNEL); > + mutex_unlock(&irqs_lock); > +} > + > +static int auxiliary_irq_create(int irq) > +{ > + int ret = 0; > + int ref; > + > + mutex_lock(&irqs_lock); > + ref = xa_to_value(xa_load(&irqs, irq)); > + if (ref) { > + ref++; > + xa_store(&irqs, irq, xa_mk_value(ref), GFP_KERNEL); > + goto out; > + } > + > + ret = xa_insert(&irqs, irq, xa_mk_value(1), GFP_KERNEL); make code simpler by one common variant of ref++ & store > + > +out: > + mutex_unlock(&irqs_lock); > + return ret; > +} > + > +/** > + * auxiliary_device_sysfs_irq_add - add a sysfs entry for the given IRQ > + * @auxdev: auxiliary bus device to add the sysfs entry. > + * @irq: The associated Linux interrupt number. > + * > + * This function should be called after auxiliary device have successfully > + * received the irq. > + * > + * Return: zero on success or an error code on failure. > + */ > +int auxiliary_device_sysfs_irq_add(struct auxiliary_device *auxdev, int irq) > +{ > + struct device *dev = &auxdev->dev; > + struct auxiliary_irq_info *info; > + int ret; > + > + ret = auxiliary_irq_create(irq); > + if (ret) > + return ret; > + > + info = kzalloc(sizeof(*info), GFP_KERNEL); > + if (!info) { > + ret = -ENOMEM; > + goto info_err; > + } > + > + sysfs_attr_init(&info->sysfs_attr.attr); > + info->sysfs_attr.attr.name = kasprintf(GFP_KERNEL, "%d", irq); > + if (!info->sysfs_attr.attr.name) { > + ret = -ENOMEM; > + goto name_err; > + } > + info->irq = irq; > + info->sysfs_attr.attr.mode = 0444; > + info->sysfs_attr.show = auxiliary_irq_mode_show; > + > + ret = xa_insert(&auxdev->irqs, irq, info, GFP_KERNEL); > + if (ret) > + goto auxdev_xa_err; > + > + ret = sysfs_add_file_to_group(&dev->kobj, &info->sysfs_attr.attr, > + auxiliary_irqs_group.name); > + if (ret) > + goto sysfs_add_err; > + > + return 0; > + > +sysfs_add_err: > + xa_erase(&auxdev->irqs, irq); > +auxdev_xa_err: > + kfree(info->sysfs_attr.attr.name); > +name_err: > + kfree(info); > +info_err: > + auxiliary_irq_destroy(irq); > + return ret; > +} > +EXPORT_SYMBOL_GPL(auxiliary_device_sysfs_irq_add); > + > +/** > + * auxiliary_device_sysfs_irq_remove - remove a sysfs entry for the given IRQ > + * @auxdev: auxiliary bus device to add the sysfs entry. > + * @irq: the IRQ to remove. > + * > + * This function should be called to remove an IRQ sysfs entry. > + */ > +void auxiliary_device_sysfs_irq_remove(struct auxiliary_device *auxdev, int irq) > +{ > + struct auxiliary_irq_info *info = xa_load(&auxdev->irqs, irq); > + struct device *dev = &auxdev->dev; > + > + sysfs_remove_file_from_group(&dev->kobj, &info->sysfs_attr.attr, > + auxiliary_irqs_group.name); > + xa_erase(&auxdev->irqs, irq); > + kfree(info->sysfs_attr.attr.name); > + kfree(info); > + auxiliary_irq_destroy(irq); > +} > +EXPORT_SYMBOL_GPL(auxiliary_device_sysfs_irq_remove); > +#endif > + > static const struct auxiliary_device_id *auxiliary_match_id(const struct auxiliary_device_id *id, > const struct auxiliary_device *auxdev) > { > @@ -295,6 +452,7 @@ EXPORT_SYMBOL_GPL(auxiliary_device_init); > * __auxiliary_device_add - add an auxiliary bus device > * @auxdev: auxiliary bus device to add to the bus > * @modname: name of the parent device's driver module > + * @irqs_sysfs_enable: whether to enable IRQs sysfs > * > * This is the third step in the three-step process to register an > * auxiliary_device. > @@ -310,7 +468,8 @@ EXPORT_SYMBOL_GPL(auxiliary_device_init); > * parameter. Only if a user requires a custom name would this version be > * called directly. > */ > -int __auxiliary_device_add(struct auxiliary_device *auxdev, const char *modname) > +int __auxiliary_device_add(struct auxiliary_device *auxdev, const char *modname, > + bool irqs_sysfs_enable) > { > struct device *dev = &auxdev->dev; > int ret; > @@ -325,6 +484,10 @@ int __auxiliary_device_add(struct auxiliary_device *auxdev, const char *modname) > dev_err(dev, "auxiliary device dev_set_name failed: %d\n", ret); > return ret; > } > + if (irqs_sysfs_enable) { > + dev->groups = auxiliary_irqs_groups; > + xa_init(&auxdev->irqs); > + } > > ret = device_add(dev); > if (ret) > diff --git a/include/linux/auxiliary_bus.h b/include/linux/auxiliary_bus.h > index de21d9d24a95..760fadb26620 100644 > --- a/include/linux/auxiliary_bus.h > +++ b/include/linux/auxiliary_bus.h > @@ -58,6 +58,7 @@ > * in > * @name: Match name found by the auxiliary device driver, > * @id: unique identitier if multiple devices of the same name are exported, > + * @irqs: irqs xarray contains irq indices which are used by the device, > * > * An auxiliary_device represents a part of its parent device's functionality. > * It is given a name that, combined with the registering drivers > @@ -138,6 +139,7 @@ > struct auxiliary_device { > struct device dev; > const char *name; > + struct xarray irqs; > u32 id; > }; > > @@ -209,8 +211,26 @@ static inline struct auxiliary_driver *to_auxiliary_drv(struct device_driver *dr > } > > int auxiliary_device_init(struct auxiliary_device *auxdev); > -int __auxiliary_device_add(struct auxiliary_device *auxdev, const char *modname); > -#define auxiliary_device_add(auxdev) __auxiliary_device_add(auxdev, KBUILD_MODNAME) > +int __auxiliary_device_add(struct auxiliary_device *auxdev, const char *modname, > + bool irqs_sysfs_enable); > +#define auxiliary_device_add(auxdev) __auxiliary_device_add(auxdev, KBUILD_MODNAME, false) > +#define auxiliary_device_add_with_irqs(auxdev) \ > + __auxiliary_device_add(auxdev, KBUILD_MODNAME, true) > + > +#ifdef CONFIG_SYSFS > +int auxiliary_device_sysfs_irq_add(struct auxiliary_device *auxdev, int irq); > +void auxiliary_device_sysfs_irq_remove(struct auxiliary_device *auxdev, > + int irq); > +#else /* CONFIG_SYSFS */ > +static inline int > +auxiliary_device_sysfs_irq_add(struct auxiliary_device *auxdev, int irq) > +{ > + return 0; > +} > + > +static inline void > +auxiliary_device_sysfs_irq_remove(struct auxiliary_device *auxdev, int irq) {} > +#endif > > static inline void auxiliary_device_uninit(struct auxiliary_device *auxdev) > {
On Tue, May 28, 2024 at 12:11:43PM +0300, Shay Drory wrote: > +#ifdef CONFIG_SYSFS > +/* Xarray of irqs to determine if irq is exclusive or shared. */ > +static DEFINE_XARRAY(irqs); > +/* Protects insertions into the irqs xarray. */ > +static DEFINE_MUTEX(irqs_lock); You access the irq xarray without grabbing the lock in places :( But again, I fail to see why the xarray is needed at all, why isn't the needed information here: > +struct auxiliary_irq_info { > + struct device_attribute sysfs_attr; > + int irq; > +}; Right there^ should contain everything you need, NOT a global array and lock at all. > +/* Auxiliary devices can share IRQs. Expose to user whether the provided IRQ is > + * shared or exclusive. Why are you using networking comment style here? :) > diff --git a/include/linux/auxiliary_bus.h b/include/linux/auxiliary_bus.h > index de21d9d24a95..760fadb26620 100644 > --- a/include/linux/auxiliary_bus.h > +++ b/include/linux/auxiliary_bus.h > @@ -58,6 +58,7 @@ > * in > * @name: Match name found by the auxiliary device driver, > * @id: unique identitier if multiple devices of the same name are exported, > + * @irqs: irqs xarray contains irq indices which are used by the device, > * > * An auxiliary_device represents a part of its parent device's functionality. > * It is given a name that, combined with the registering drivers > @@ -138,6 +139,7 @@ > struct auxiliary_device { > struct device dev; > const char *name; > + struct xarray irqs; wait, why is an xarray added here too? That feels wrong, or odd, or something as you seem to have multiple xarrays here when it feels like you need none. confused, greg k-h
On 28/05/2024 21:00, Greg KH wrote: > External email: Use caution opening links or attachments > > > On Tue, May 28, 2024 at 12:11:43PM +0300, Shay Drory wrote: >> +#ifdef CONFIG_SYSFS >> +/* Xarray of irqs to determine if irq is exclusive or shared. */ >> +static DEFINE_XARRAY(irqs); >> +/* Protects insertions into the irqs xarray. */ >> +static DEFINE_MUTEX(irqs_lock); > > You access the irq xarray without grabbing the lock in places :( > > But again, I fail to see why the xarray is needed at all, why isn't the > needed information here: > >> +struct auxiliary_irq_info { >> + struct device_attribute sysfs_attr; >> + int irq; >> +}; > > Right there^ should contain everything you need, NOT a global array and > lock at all. 1) one xarray is per aux device that indicates which IRQs irqs are used by this device. this xarray is holding the info above. 2) second xarray is global that tracks if irq share between multiple aux devices or exclusive to aux device. > >> +/* Auxiliary devices can share IRQs. Expose to user whether the provided IRQ is >> + * shared or exclusive. > > Why are you using networking comment style here? :) correct, will fix in next version > >> diff --git a/include/linux/auxiliary_bus.h b/include/linux/auxiliary_bus.h >> index de21d9d24a95..760fadb26620 100644 >> --- a/include/linux/auxiliary_bus.h >> +++ b/include/linux/auxiliary_bus.h >> @@ -58,6 +58,7 @@ >> * in >> * @name: Match name found by the auxiliary device driver, >> * @id: unique identitier if multiple devices of the same name are exported, >> + * @irqs: irqs xarray contains irq indices which are used by the device, >> * >> * An auxiliary_device represents a part of its parent device's functionality. >> * It is given a name that, combined with the registering drivers >> @@ -138,6 +139,7 @@ >> struct auxiliary_device { >> struct device dev; >> const char *name; >> + struct xarray irqs; > > wait, why is an xarray added here too? That feels wrong, or odd, or > something as you seem to have multiple xarrays here when it feels like > you need none. > please look the answer above > confused, > > greg k-h
On 28/05/2024 17:43, Przemek Kitszel wrote: > External email: Use caution opening links or attachments > > > On 5/28/24 11:11, Shay Drory wrote: >> Some PCI subfunctions (SF) are anchored on the auxiliary bus. PCI >> physical and virtual functions are anchored on the PCI bus. The irq >> information of each such function is visible to users via sysfs >> directory "msi_irqs" containing file for each irq entry. However, for >> PCI SFs such information is unavailable. Due to this users have no >> visibility on IRQs used by the SFs. >> Secondly, an SF can be multi function device supporting rdma, netdevice >> and more. Without irq information at the bus level, the user is unable >> to view or use the affinity of the SF IRQs. >> >> Hence to match to the equivalent PCI PFs and VFs, add "irqs" directory, >> for supporting auxiliary devices, containing file for each irq entry. >> >> Additionally, the PCI SFs sometimes share the IRQs with peer SFs. This >> information is also not available to the users. To overcome this >> limitation, each irq sysfs entry shows if irq is exclusive or shared. >> >> For example: >> $ ls /sys/bus/auxiliary/devices/mlx5_core.sf.1/irqs/ >> 50 51 52 53 54 55 56 57 58 >> $ cat /sys/bus/auxiliary/devices/mlx5_core.sf.1/irqs/52 >> exclusive >> >> Reviewed-by: Parav Pandit <parav@nvidia.com> >> Signed-off-by: Shay Drory <shayd@nvidia.com> >> >> --- >> v4-v5: >> - restore global mutex and replace refcount_t with simple integer (Greg) >> v3->4: >> - remove global mutex (Przemek) >> v2->v3: >> - fix function declaration in case SYSFS isn't defined >> v1->v2: >> - move #ifdefs from drivers/base/auxiliary.c to >> include/linux/auxiliary_bus.h (Greg) >> - use EXPORT_SYMBOL_GPL instead of EXPORT_SYMBOL (Greg) >> - Fix kzalloc(ref) to kzalloc(*ref) (Simon) >> - Add return description in auxiliary_device_sysfs_irq_add() kdoc (Simon) >> - Fix auxiliary_irq_mode_show doc (kernel test boot) >> --- >> Documentation/ABI/testing/sysfs-bus-auxiliary | 14 ++ >> drivers/base/auxiliary.c | 165 +++++++++++++++++- >> include/linux/auxiliary_bus.h | 24 ++- >> 3 files changed, 200 insertions(+), 3 deletions(-) >> create mode 100644 Documentation/ABI/testing/sysfs-bus-auxiliary >> >> diff --git a/Documentation/ABI/testing/sysfs-bus-auxiliary >> b/Documentation/ABI/testing/sysfs-bus-auxiliary >> new file mode 100644 >> index 000000000000..3b8299d49d9e >> --- /dev/null >> +++ b/Documentation/ABI/testing/sysfs-bus-auxiliary >> @@ -0,0 +1,14 @@ >> +What: /sys/bus/auxiliary/devices/.../irqs/ >> +Date: April, 2024 >> +Contact: Shay Drory <shayd@nvidia.com> >> +Description: >> + The /sys/devices/.../irqs directory contains a variable >> set of >> + files, with each file is named as irq number similar to >> PCI PF >> + or VF's irq number located in msi_irqs directory. >> + >> +What: /sys/bus/auxiliary/devices/.../irqs/<N> >> +Date: April, 2024 >> +Contact: Shay Drory <shayd@nvidia.com> >> +Description: >> + auxiliary devices can share IRQs. This attribute >> indicates if >> + the irq is shared with other SFs or exclusively used by >> the SF. >> diff --git a/drivers/base/auxiliary.c b/drivers/base/auxiliary.c >> index d3a2c40c2f12..579d755dcbee 100644 >> --- a/drivers/base/auxiliary.c >> +++ b/drivers/base/auxiliary.c >> @@ -158,6 +158,163 @@ >> * }; >> */ >> >> +#ifdef CONFIG_SYSFS >> +/* Xarray of irqs to determine if irq is exclusive or shared. */ >> +static DEFINE_XARRAY(irqs); >> +/* Protects insertions into the irqs xarray. */ >> +static DEFINE_MUTEX(irqs_lock); >> + >> +struct auxiliary_irq_info { >> + struct device_attribute sysfs_attr; >> + int irq; >> +}; >> + >> +static struct attribute *auxiliary_irq_attrs[] = { >> + NULL >> +}; >> + >> +static const struct attribute_group auxiliary_irqs_group = { >> + .name = "irqs", >> + .attrs = auxiliary_irq_attrs, >> +}; >> + >> +static const struct attribute_group *auxiliary_irqs_groups[] = { >> + &auxiliary_irqs_group, >> + NULL >> +}; >> + >> +/* Auxiliary devices can share IRQs. Expose to user whether the >> provided IRQ is >> + * shared or exclusive. >> + */ >> +static ssize_t auxiliary_irq_mode_show(struct device *dev, >> + struct device_attribute *attr, >> char *buf) >> +{ >> + struct auxiliary_irq_info *info = >> + container_of(attr, struct auxiliary_irq_info, sysfs_attr); >> + int ref = xa_to_value(xa_load(&irqs, info->irq)); > > just a note that you forgot to take the global lock here correct, will fix in next version > >> + >> + if (!ref) >> + return -ENOENT; >> + if (ref > 1) >> + return sysfs_emit(buf, "%s\n", "shared"); >> + else >> + return sysfs_emit(buf, "%s\n", "exclusive"); >> +} >> + >> +static void auxiliary_irq_destroy(int irq) >> +{ >> + int ref; >> + >> + mutex_lock(&irqs_lock); >> + ref = xa_to_value(xa_load(&irqs, irq)); >> + if (!(--ref)) >> + xa_erase(&irqs, irq); > > Global lock makes it indeed simpler to support xa_erase()-on-zero. > There are simple solutions without erasing zero elements (you could > have non-allocating store), but let's say we are leaving "the simplest" > room then :) > >> + else >> + xa_store(&irqs, irq, xa_mk_value(ref), GFP_KERNEL); >> + mutex_unlock(&irqs_lock); >> +} >> + >> +static int auxiliary_irq_create(int irq) >> +{ >> + int ret = 0; >> + int ref; >> + >> + mutex_lock(&irqs_lock); >> + ref = xa_to_value(xa_load(&irqs, irq)); >> + if (ref) { >> + ref++; >> + xa_store(&irqs, irq, xa_mk_value(ref), GFP_KERNEL); >> + goto out; >> + } >> + >> + ret = xa_insert(&irqs, irq, xa_mk_value(1), GFP_KERNEL); > > make code simpler by one common variant of ref++ & store Nice :) will change in next version. > >> + >> +out: >> + mutex_unlock(&irqs_lock); >> + return ret; >> +} >> + >> +/** >> + * auxiliary_device_sysfs_irq_add - add a sysfs entry for the given IRQ >> + * @auxdev: auxiliary bus device to add the sysfs entry. >> + * @irq: The associated Linux interrupt number. >> + * >> + * This function should be called after auxiliary device have >> successfully >> + * received the irq. >> + * >> + * Return: zero on success or an error code on failure. >> + */ >> +int auxiliary_device_sysfs_irq_add(struct auxiliary_device *auxdev, >> int irq) >> +{ >> + struct device *dev = &auxdev->dev; >> + struct auxiliary_irq_info *info; >> + int ret; >> + >> + ret = auxiliary_irq_create(irq); >> + if (ret) >> + return ret; >> + >> + info = kzalloc(sizeof(*info), GFP_KERNEL); >> + if (!info) { >> + ret = -ENOMEM; >> + goto info_err; >> + } >> + >> + sysfs_attr_init(&info->sysfs_attr.attr); >> + info->sysfs_attr.attr.name = kasprintf(GFP_KERNEL, "%d", irq); >> + if (!info->sysfs_attr.attr.name) { >> + ret = -ENOMEM; >> + goto name_err; >> + } >> + info->irq = irq; >> + info->sysfs_attr.attr.mode = 0444; >> + info->sysfs_attr.show = auxiliary_irq_mode_show; >> + >> + ret = xa_insert(&auxdev->irqs, irq, info, GFP_KERNEL); >> + if (ret) >> + goto auxdev_xa_err; >> + >> + ret = sysfs_add_file_to_group(&dev->kobj, &info->sysfs_attr.attr, >> + auxiliary_irqs_group.name); >> + if (ret) >> + goto sysfs_add_err; >> + >> + return 0; >> + >> +sysfs_add_err: >> + xa_erase(&auxdev->irqs, irq); >> +auxdev_xa_err: >> + kfree(info->sysfs_attr.attr.name); >> +name_err: >> + kfree(info); >> +info_err: >> + auxiliary_irq_destroy(irq); >> + return ret; >> +} >> +EXPORT_SYMBOL_GPL(auxiliary_device_sysfs_irq_add); >> + >> +/** >> + * auxiliary_device_sysfs_irq_remove - remove a sysfs entry for the >> given IRQ >> + * @auxdev: auxiliary bus device to add the sysfs entry. >> + * @irq: the IRQ to remove. >> + * >> + * This function should be called to remove an IRQ sysfs entry. >> + */ >> +void auxiliary_device_sysfs_irq_remove(struct auxiliary_device >> *auxdev, int irq) >> +{ >> + struct auxiliary_irq_info *info = xa_load(&auxdev->irqs, irq); >> + struct device *dev = &auxdev->dev; >> + >> + sysfs_remove_file_from_group(&dev->kobj, &info->sysfs_attr.attr, >> + auxiliary_irqs_group.name); >> + xa_erase(&auxdev->irqs, irq); >> + kfree(info->sysfs_attr.attr.name); >> + kfree(info); >> + auxiliary_irq_destroy(irq); >> +} >> +EXPORT_SYMBOL_GPL(auxiliary_device_sysfs_irq_remove); >> +#endif >> + >> static const struct auxiliary_device_id *auxiliary_match_id(const >> struct auxiliary_device_id *id, >> const struct >> auxiliary_device *auxdev) >> { >> @@ -295,6 +452,7 @@ EXPORT_SYMBOL_GPL(auxiliary_device_init); >> * __auxiliary_device_add - add an auxiliary bus device >> * @auxdev: auxiliary bus device to add to the bus >> * @modname: name of the parent device's driver module >> + * @irqs_sysfs_enable: whether to enable IRQs sysfs >> * >> * This is the third step in the three-step process to register an >> * auxiliary_device. >> @@ -310,7 +468,8 @@ EXPORT_SYMBOL_GPL(auxiliary_device_init); >> * parameter. Only if a user requires a custom name would this >> version be >> * called directly. >> */ >> -int __auxiliary_device_add(struct auxiliary_device *auxdev, const >> char *modname) >> +int __auxiliary_device_add(struct auxiliary_device *auxdev, const >> char *modname, >> + bool irqs_sysfs_enable) >> { >> struct device *dev = &auxdev->dev; >> int ret; >> @@ -325,6 +484,10 @@ int __auxiliary_device_add(struct >> auxiliary_device *auxdev, const char *modname) >> dev_err(dev, "auxiliary device dev_set_name failed: >> %d\n", ret); >> return ret; >> } >> + if (irqs_sysfs_enable) { >> + dev->groups = auxiliary_irqs_groups; >> + xa_init(&auxdev->irqs); >> + } >> >> ret = device_add(dev); >> if (ret) >> diff --git a/include/linux/auxiliary_bus.h >> b/include/linux/auxiliary_bus.h >> index de21d9d24a95..760fadb26620 100644 >> --- a/include/linux/auxiliary_bus.h >> +++ b/include/linux/auxiliary_bus.h >> @@ -58,6 +58,7 @@ >> * in >> * @name: Match name found by the auxiliary device driver, >> * @id: unique identitier if multiple devices of the same name are >> exported, >> + * @irqs: irqs xarray contains irq indices which are used by the device, >> * >> * An auxiliary_device represents a part of its parent device's >> functionality. >> * It is given a name that, combined with the registering drivers >> @@ -138,6 +139,7 @@ >> struct auxiliary_device { >> struct device dev; >> const char *name; >> + struct xarray irqs; >> u32 id; >> }; >> >> @@ -209,8 +211,26 @@ static inline struct auxiliary_driver >> *to_auxiliary_drv(struct device_driver *dr >> } >> >> int auxiliary_device_init(struct auxiliary_device *auxdev); >> -int __auxiliary_device_add(struct auxiliary_device *auxdev, const >> char *modname); >> -#define auxiliary_device_add(auxdev) __auxiliary_device_add(auxdev, >> KBUILD_MODNAME) >> +int __auxiliary_device_add(struct auxiliary_device *auxdev, const >> char *modname, >> + bool irqs_sysfs_enable); >> +#define auxiliary_device_add(auxdev) __auxiliary_device_add(auxdev, >> KBUILD_MODNAME, false) >> +#define auxiliary_device_add_with_irqs(auxdev) \ >> + __auxiliary_device_add(auxdev, KBUILD_MODNAME, true) >> + >> +#ifdef CONFIG_SYSFS >> +int auxiliary_device_sysfs_irq_add(struct auxiliary_device *auxdev, >> int irq); >> +void auxiliary_device_sysfs_irq_remove(struct auxiliary_device *auxdev, >> + int irq); >> +#else /* CONFIG_SYSFS */ >> +static inline int >> +auxiliary_device_sysfs_irq_add(struct auxiliary_device *auxdev, int irq) >> +{ >> + return 0; >> +} >> + >> +static inline void >> +auxiliary_device_sysfs_irq_remove(struct auxiliary_device *auxdev, >> int irq) {} >> +#endif >> >> static inline void auxiliary_device_uninit(struct auxiliary_device >> *auxdev) >> { >
On Wed, May 29, 2024 at 09:29:33AM +0300, Shay Drori wrote: > > > On 28/05/2024 21:00, Greg KH wrote: > > External email: Use caution opening links or attachments > > > > > > On Tue, May 28, 2024 at 12:11:43PM +0300, Shay Drory wrote: > > > +#ifdef CONFIG_SYSFS > > > +/* Xarray of irqs to determine if irq is exclusive or shared. */ > > > +static DEFINE_XARRAY(irqs); > > > +/* Protects insertions into the irqs xarray. */ > > > +static DEFINE_MUTEX(irqs_lock); > > > > You access the irq xarray without grabbing the lock in places :( > > > > But again, I fail to see why the xarray is needed at all, why isn't the > > needed information here: > > > > > +struct auxiliary_irq_info { > > > + struct device_attribute sysfs_attr; > > > + int irq; > > > +}; > > > > Right there^ should contain everything you need, NOT a global array and > > lock at all. > > > 1) one xarray is per aux device that indicates which IRQs irqs are used > by this device. this xarray is holding the info above. Ok, please document that better, it's not obvious. > 2) second xarray is global that tracks if irq share between multiple aux > devices or exclusive to aux device. That should not be a "global" thing, as now you are getting into what the msi irq core should be handling, NOT the aux device. Userspace should be able to determine, just by the number, if it is "shared" or not by looking at them all, so why need to add complex logic here to attempt to also mirror this information? Doesn't the irq layer track this sufficiently? And it wouldn't even be correct if an irq was "shared" by a device that was NOT controlled by an aux device so it could be incorrect. thanks, greg k-h
diff --git a/Documentation/ABI/testing/sysfs-bus-auxiliary b/Documentation/ABI/testing/sysfs-bus-auxiliary new file mode 100644 index 000000000000..3b8299d49d9e --- /dev/null +++ b/Documentation/ABI/testing/sysfs-bus-auxiliary @@ -0,0 +1,14 @@ +What: /sys/bus/auxiliary/devices/.../irqs/ +Date: April, 2024 +Contact: Shay Drory <shayd@nvidia.com> +Description: + The /sys/devices/.../irqs directory contains a variable set of + files, with each file is named as irq number similar to PCI PF + or VF's irq number located in msi_irqs directory. + +What: /sys/bus/auxiliary/devices/.../irqs/<N> +Date: April, 2024 +Contact: Shay Drory <shayd@nvidia.com> +Description: + auxiliary devices can share IRQs. This attribute indicates if + the irq is shared with other SFs or exclusively used by the SF. diff --git a/drivers/base/auxiliary.c b/drivers/base/auxiliary.c index d3a2c40c2f12..579d755dcbee 100644 --- a/drivers/base/auxiliary.c +++ b/drivers/base/auxiliary.c @@ -158,6 +158,163 @@ * }; */ +#ifdef CONFIG_SYSFS +/* Xarray of irqs to determine if irq is exclusive or shared. */ +static DEFINE_XARRAY(irqs); +/* Protects insertions into the irqs xarray. */ +static DEFINE_MUTEX(irqs_lock); + +struct auxiliary_irq_info { + struct device_attribute sysfs_attr; + int irq; +}; + +static struct attribute *auxiliary_irq_attrs[] = { + NULL +}; + +static const struct attribute_group auxiliary_irqs_group = { + .name = "irqs", + .attrs = auxiliary_irq_attrs, +}; + +static const struct attribute_group *auxiliary_irqs_groups[] = { + &auxiliary_irqs_group, + NULL +}; + +/* Auxiliary devices can share IRQs. Expose to user whether the provided IRQ is + * shared or exclusive. + */ +static ssize_t auxiliary_irq_mode_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct auxiliary_irq_info *info = + container_of(attr, struct auxiliary_irq_info, sysfs_attr); + int ref = xa_to_value(xa_load(&irqs, info->irq)); + + if (!ref) + return -ENOENT; + if (ref > 1) + return sysfs_emit(buf, "%s\n", "shared"); + else + return sysfs_emit(buf, "%s\n", "exclusive"); +} + +static void auxiliary_irq_destroy(int irq) +{ + int ref; + + mutex_lock(&irqs_lock); + ref = xa_to_value(xa_load(&irqs, irq)); + if (!(--ref)) + xa_erase(&irqs, irq); + else + xa_store(&irqs, irq, xa_mk_value(ref), GFP_KERNEL); + mutex_unlock(&irqs_lock); +} + +static int auxiliary_irq_create(int irq) +{ + int ret = 0; + int ref; + + mutex_lock(&irqs_lock); + ref = xa_to_value(xa_load(&irqs, irq)); + if (ref) { + ref++; + xa_store(&irqs, irq, xa_mk_value(ref), GFP_KERNEL); + goto out; + } + + ret = xa_insert(&irqs, irq, xa_mk_value(1), GFP_KERNEL); + +out: + mutex_unlock(&irqs_lock); + return ret; +} + +/** + * auxiliary_device_sysfs_irq_add - add a sysfs entry for the given IRQ + * @auxdev: auxiliary bus device to add the sysfs entry. + * @irq: The associated Linux interrupt number. + * + * This function should be called after auxiliary device have successfully + * received the irq. + * + * Return: zero on success or an error code on failure. + */ +int auxiliary_device_sysfs_irq_add(struct auxiliary_device *auxdev, int irq) +{ + struct device *dev = &auxdev->dev; + struct auxiliary_irq_info *info; + int ret; + + ret = auxiliary_irq_create(irq); + if (ret) + return ret; + + info = kzalloc(sizeof(*info), GFP_KERNEL); + if (!info) { + ret = -ENOMEM; + goto info_err; + } + + sysfs_attr_init(&info->sysfs_attr.attr); + info->sysfs_attr.attr.name = kasprintf(GFP_KERNEL, "%d", irq); + if (!info->sysfs_attr.attr.name) { + ret = -ENOMEM; + goto name_err; + } + info->irq = irq; + info->sysfs_attr.attr.mode = 0444; + info->sysfs_attr.show = auxiliary_irq_mode_show; + + ret = xa_insert(&auxdev->irqs, irq, info, GFP_KERNEL); + if (ret) + goto auxdev_xa_err; + + ret = sysfs_add_file_to_group(&dev->kobj, &info->sysfs_attr.attr, + auxiliary_irqs_group.name); + if (ret) + goto sysfs_add_err; + + return 0; + +sysfs_add_err: + xa_erase(&auxdev->irqs, irq); +auxdev_xa_err: + kfree(info->sysfs_attr.attr.name); +name_err: + kfree(info); +info_err: + auxiliary_irq_destroy(irq); + return ret; +} +EXPORT_SYMBOL_GPL(auxiliary_device_sysfs_irq_add); + +/** + * auxiliary_device_sysfs_irq_remove - remove a sysfs entry for the given IRQ + * @auxdev: auxiliary bus device to add the sysfs entry. + * @irq: the IRQ to remove. + * + * This function should be called to remove an IRQ sysfs entry. + */ +void auxiliary_device_sysfs_irq_remove(struct auxiliary_device *auxdev, int irq) +{ + struct auxiliary_irq_info *info = xa_load(&auxdev->irqs, irq); + struct device *dev = &auxdev->dev; + + sysfs_remove_file_from_group(&dev->kobj, &info->sysfs_attr.attr, + auxiliary_irqs_group.name); + xa_erase(&auxdev->irqs, irq); + kfree(info->sysfs_attr.attr.name); + kfree(info); + auxiliary_irq_destroy(irq); +} +EXPORT_SYMBOL_GPL(auxiliary_device_sysfs_irq_remove); +#endif + static const struct auxiliary_device_id *auxiliary_match_id(const struct auxiliary_device_id *id, const struct auxiliary_device *auxdev) { @@ -295,6 +452,7 @@ EXPORT_SYMBOL_GPL(auxiliary_device_init); * __auxiliary_device_add - add an auxiliary bus device * @auxdev: auxiliary bus device to add to the bus * @modname: name of the parent device's driver module + * @irqs_sysfs_enable: whether to enable IRQs sysfs * * This is the third step in the three-step process to register an * auxiliary_device. @@ -310,7 +468,8 @@ EXPORT_SYMBOL_GPL(auxiliary_device_init); * parameter. Only if a user requires a custom name would this version be * called directly. */ -int __auxiliary_device_add(struct auxiliary_device *auxdev, const char *modname) +int __auxiliary_device_add(struct auxiliary_device *auxdev, const char *modname, + bool irqs_sysfs_enable) { struct device *dev = &auxdev->dev; int ret; @@ -325,6 +484,10 @@ int __auxiliary_device_add(struct auxiliary_device *auxdev, const char *modname) dev_err(dev, "auxiliary device dev_set_name failed: %d\n", ret); return ret; } + if (irqs_sysfs_enable) { + dev->groups = auxiliary_irqs_groups; + xa_init(&auxdev->irqs); + } ret = device_add(dev); if (ret) diff --git a/include/linux/auxiliary_bus.h b/include/linux/auxiliary_bus.h index de21d9d24a95..760fadb26620 100644 --- a/include/linux/auxiliary_bus.h +++ b/include/linux/auxiliary_bus.h @@ -58,6 +58,7 @@ * in * @name: Match name found by the auxiliary device driver, * @id: unique identitier if multiple devices of the same name are exported, + * @irqs: irqs xarray contains irq indices which are used by the device, * * An auxiliary_device represents a part of its parent device's functionality. * It is given a name that, combined with the registering drivers @@ -138,6 +139,7 @@ struct auxiliary_device { struct device dev; const char *name; + struct xarray irqs; u32 id; }; @@ -209,8 +211,26 @@ static inline struct auxiliary_driver *to_auxiliary_drv(struct device_driver *dr } int auxiliary_device_init(struct auxiliary_device *auxdev); -int __auxiliary_device_add(struct auxiliary_device *auxdev, const char *modname); -#define auxiliary_device_add(auxdev) __auxiliary_device_add(auxdev, KBUILD_MODNAME) +int __auxiliary_device_add(struct auxiliary_device *auxdev, const char *modname, + bool irqs_sysfs_enable); +#define auxiliary_device_add(auxdev) __auxiliary_device_add(auxdev, KBUILD_MODNAME, false) +#define auxiliary_device_add_with_irqs(auxdev) \ + __auxiliary_device_add(auxdev, KBUILD_MODNAME, true) + +#ifdef CONFIG_SYSFS +int auxiliary_device_sysfs_irq_add(struct auxiliary_device *auxdev, int irq); +void auxiliary_device_sysfs_irq_remove(struct auxiliary_device *auxdev, + int irq); +#else /* CONFIG_SYSFS */ +static inline int +auxiliary_device_sysfs_irq_add(struct auxiliary_device *auxdev, int irq) +{ + return 0; +} + +static inline void +auxiliary_device_sysfs_irq_remove(struct auxiliary_device *auxdev, int irq) {} +#endif static inline void auxiliary_device_uninit(struct auxiliary_device *auxdev) {