| Message ID | 1594898629-18790-4-git-send-email-lingshan.zhu@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | IRQ offloading for vDPA | expand |
On 2020/7/16 下午7:23, Zhu Lingshan wrote: > This commit implements IRQ offloading helpers Let's say "vq irq allocate/free helpers" here. > in vDPA core by > introducing two couple of functions: > > vdpa_alloc_vq_irq() and vdpa_free_vq_irq(): request irq and free > irq, will setup irq offloading. > > vdpa_setup_irq() and vdpa_unsetup_irq(): supportive functions, > will call vhost_vdpa helpers. > > Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com> > Suggested-by: Jason Wang <jasowang@redhat.com> > --- > drivers/vdpa/vdpa.c | 42 ++++++++++++++++++++++++++++++++++++++++++ > include/linux/vdpa.h | 13 +++++++++++++ > 2 files changed, 55 insertions(+) > > diff --git a/drivers/vdpa/vdpa.c b/drivers/vdpa/vdpa.c > index ff6562f..cce4d91 100644 > --- a/drivers/vdpa/vdpa.c > +++ b/drivers/vdpa/vdpa.c > @@ -163,6 +163,48 @@ void vdpa_unregister_driver(struct vdpa_driver *drv) > } > EXPORT_SYMBOL_GPL(vdpa_unregister_driver); > > +static void vdpa_setup_irq(struct vdpa_device *vdev, int qid, int irq) > +{ > + struct vdpa_driver *drv = drv_to_vdpa(vdev->dev.driver); > + > + if (drv->setup_vq_irq) > + drv->setup_vq_irq(vdev, qid, irq); > +} > + > +static void vdpa_unsetup_irq(struct vdpa_device *vdev, int qid) > +{ > + struct vdpa_driver *drv = drv_to_vdpa(vdev->dev.driver); > + > + if (drv->unsetup_vq_irq) > + drv->unsetup_vq_irq(vdev, qid); Do you need to check the existence of drv before calling unset_vq_irq()? And how can this synchronize with driver releasing and binding? > +} > + > +int vdpa_alloc_vq_irq(struct device *dev, struct vdpa_device *vdev, > + unsigned int irq, irq_handler_t handler, > + unsigned long irqflags, const char *devname, void *dev_id, > + int qid) Let's add comment as what has been done by other exported helpers. > +{ > + int ret; > + > + ret = devm_request_irq(dev, irq, handler, irqflags, devname, dev_id); > + if (ret) > + dev_err(dev, "Failed to request irq for vq %d\n", qid); > + else > + vdpa_setup_irq(vdev, qid, irq); > + > + return ret; > + > +} > +EXPORT_SYMBOL_GPL(vdpa_alloc_vq_irq); > + > +void vdpa_free_vq_irq(struct device *dev, struct vdpa_device *vdev, int irq, > + int qid, void *dev_id) > +{ > + devm_free_irq(dev, irq, dev_id); > + vdpa_unsetup_irq(vdev, qid); > +} > +EXPORT_SYMBOL_GPL(vdpa_free_vq_irq); > + > static int vdpa_init(void) > { > return bus_register(&vdpa_bus); > diff --git a/include/linux/vdpa.h b/include/linux/vdpa.h > index 239db79..7d64d83 100644 > --- a/include/linux/vdpa.h > +++ b/include/linux/vdpa.h > @@ -220,17 +220,30 @@ struct vdpa_device *__vdpa_alloc_device(struct device *parent, > > int vdpa_register_device(struct vdpa_device *vdev); > void vdpa_unregister_device(struct vdpa_device *vdev); > +/* request irq for a vq, setup irq offloading if its a vhost_vdpa vq */ Let's do the documentation in vdpa.c, and again, document the devres implications or j_xxxust name it as vdpa_devm_xxx. > +int vdpa_alloc_vq_irq(struct device *dev, struct vdpa_device *vdev, > + unsigned int irq, irq_handler_t handler, > + unsigned long irqflags, const char *devname, void *dev_id, > + int qid); > +/* free irq for a vq, unsetup irq offloading if its a vhost_vdpa vq */ > +void vdpa_free_vq_irq(struct device *dev, struct vdpa_device *vdev, int irq, > + int qid, void *dev_id); > + > > /** > * vdpa_driver - operations for a vDPA driver > * @driver: underlying device driver > * @probe: the function to call when a device is found. Returns 0 or -errno. > * @remove: the function to call when a device is removed. > + * @setup_vq_irq: setup irq offloading for a vhost_vdpa vq. > + * @unsetup_vq_irq: unsetup offloading for a vhost_vdpa vq. Let's not limit the methods for a specific use case like irq offloading here. > */ > struct vdpa_driver { > struct device_driver driver; > int (*probe)(struct vdpa_device *vdev); > void (*remove)(struct vdpa_device *vdev); > + void (*setup_vq_irq)(struct vdpa_device *vdev, int qid, int irq); > + void (*unsetup_vq_irq)(struct vdpa_device *vdev, int qid); To be consistent with the exported helper, let's use alloc_vq_irq/free_vq_irq Thanks > }; > > #define vdpa_register_driver(drv) \
On 2020/7/20 下午5:07, Zhu, Lingshan wrote: >>> >>> +} >>> + >>> +static void vdpa_unsetup_irq(struct vdpa_device *vdev, int qid) >>> +{ >>> + struct vdpa_driver *drv = drv_to_vdpa(vdev->dev.driver); >>> + >>> + if (drv->unsetup_vq_irq) >>> + drv->unsetup_vq_irq(vdev, qid); >> >> >> Do you need to check the existence of drv before calling unset_vq_irq()? > Yes, we should check this when we take the releasing path into account. >> >> And how can this synchronize with driver releasing and binding? > Will add an vdpa_unsetup_irq() call in vhsot_vdpa_release(). > For binding, I think it is a new dev bound to the the driver, > it should go through the vdpa_setup_irq() routine. or if it is > a device re-bind to vhost_vdpa, I think we have cleaned up > irq_bypass_producer for it as we would call vhdpa_unsetup_irq() > in the release function. I meant can the following things happen? 1) some vDPA device driver probe the hardware and call vdpa_request_irq() in its PCI probe function. 2) vDPA device is probed by vhost-vDPA Then irq bypass can't work since we when vdpa_unsetup_irq() is called, there's no driver bound. Or is there a requirement that vdap_request/free_irq() must be called somewhere (e.g in the set_status bus operations)? If yes, we need document those requirements. Thanks
On 2020/7/21 上午10:02, Zhu, Lingshan wrote: > > > On 7/20/2020 5:40 PM, Jason Wang wrote: >> >> On 2020/7/20 下午5:07, Zhu, Lingshan wrote: >>>>> >>>>> +} >>>>> + >>>>> +static void vdpa_unsetup_irq(struct vdpa_device *vdev, int qid) >>>>> +{ >>>>> + struct vdpa_driver *drv = drv_to_vdpa(vdev->dev.driver); >>>>> + >>>>> + if (drv->unsetup_vq_irq) >>>>> + drv->unsetup_vq_irq(vdev, qid); >>>> >>>> >>>> Do you need to check the existence of drv before calling >>>> unset_vq_irq()? >>> Yes, we should check this when we take the releasing path into account. >>>> >>>> And how can this synchronize with driver releasing and binding? >>> Will add an vdpa_unsetup_irq() call in vhsot_vdpa_release(). >>> For binding, I think it is a new dev bound to the the driver, >>> it should go through the vdpa_setup_irq() routine. or if it is >>> a device re-bind to vhost_vdpa, I think we have cleaned up >>> irq_bypass_producer for it as we would call vhdpa_unsetup_irq() >>> in the release function. >> >> >> I meant can the following things happen? >> >> 1) some vDPA device driver probe the hardware and call >> vdpa_request_irq() in its PCI probe function. >> 2) vDPA device is probed by vhost-vDPA >> >> Then irq bypass can't work since we when vdpa_unsetup_irq() is >> called, there's no driver bound. Or is there a requirement that >> vdap_request/free_irq() must be called somewhere (e.g in the >> set_status bus operations)? If yes, we need document those requirements. > vdpa_unseup_irq is only called when we want to unregister the producer, Typo, I meant vdpa_setup_irq(). Thanks > now we have two code path using it: free_irq and relaase(). I agree we can document this requirements for the helpers, these functions can only be called through status changes(DRIVER_OK and !DRIVER_OK). > > Thanks, > BR > Zhu Lingshan >> >> Thanks >>
diff --git a/drivers/vdpa/vdpa.c b/drivers/vdpa/vdpa.c index ff6562f..cce4d91 100644 --- a/drivers/vdpa/vdpa.c +++ b/drivers/vdpa/vdpa.c @@ -163,6 +163,48 @@ void vdpa_unregister_driver(struct vdpa_driver *drv) } EXPORT_SYMBOL_GPL(vdpa_unregister_driver); +static void vdpa_setup_irq(struct vdpa_device *vdev, int qid, int irq) +{ + struct vdpa_driver *drv = drv_to_vdpa(vdev->dev.driver); + + if (drv->setup_vq_irq) + drv->setup_vq_irq(vdev, qid, irq); +} + +static void vdpa_unsetup_irq(struct vdpa_device *vdev, int qid) +{ + struct vdpa_driver *drv = drv_to_vdpa(vdev->dev.driver); + + if (drv->unsetup_vq_irq) + drv->unsetup_vq_irq(vdev, qid); +} + +int vdpa_alloc_vq_irq(struct device *dev, struct vdpa_device *vdev, + unsigned int irq, irq_handler_t handler, + unsigned long irqflags, const char *devname, void *dev_id, + int qid) +{ + int ret; + + ret = devm_request_irq(dev, irq, handler, irqflags, devname, dev_id); + if (ret) + dev_err(dev, "Failed to request irq for vq %d\n", qid); + else + vdpa_setup_irq(vdev, qid, irq); + + return ret; + +} +EXPORT_SYMBOL_GPL(vdpa_alloc_vq_irq); + +void vdpa_free_vq_irq(struct device *dev, struct vdpa_device *vdev, int irq, + int qid, void *dev_id) +{ + devm_free_irq(dev, irq, dev_id); + vdpa_unsetup_irq(vdev, qid); +} +EXPORT_SYMBOL_GPL(vdpa_free_vq_irq); + static int vdpa_init(void) { return bus_register(&vdpa_bus); diff --git a/include/linux/vdpa.h b/include/linux/vdpa.h index 239db79..7d64d83 100644 --- a/include/linux/vdpa.h +++ b/include/linux/vdpa.h @@ -220,17 +220,30 @@ struct vdpa_device *__vdpa_alloc_device(struct device *parent, int vdpa_register_device(struct vdpa_device *vdev); void vdpa_unregister_device(struct vdpa_device *vdev); +/* request irq for a vq, setup irq offloading if its a vhost_vdpa vq */ +int vdpa_alloc_vq_irq(struct device *dev, struct vdpa_device *vdev, + unsigned int irq, irq_handler_t handler, + unsigned long irqflags, const char *devname, void *dev_id, + int qid); +/* free irq for a vq, unsetup irq offloading if its a vhost_vdpa vq */ +void vdpa_free_vq_irq(struct device *dev, struct vdpa_device *vdev, int irq, + int qid, void *dev_id); + /** * vdpa_driver - operations for a vDPA driver * @driver: underlying device driver * @probe: the function to call when a device is found. Returns 0 or -errno. * @remove: the function to call when a device is removed. + * @setup_vq_irq: setup irq offloading for a vhost_vdpa vq. + * @unsetup_vq_irq: unsetup offloading for a vhost_vdpa vq. */ struct vdpa_driver { struct device_driver driver; int (*probe)(struct vdpa_device *vdev); void (*remove)(struct vdpa_device *vdev); + void (*setup_vq_irq)(struct vdpa_device *vdev, int qid, int irq); + void (*unsetup_vq_irq)(struct vdpa_device *vdev, int qid); }; #define vdpa_register_driver(drv) \
This commit implements IRQ offloading helpers in vDPA core by introducing two couple of functions: vdpa_alloc_vq_irq() and vdpa_free_vq_irq(): request irq and free irq, will setup irq offloading. vdpa_setup_irq() and vdpa_unsetup_irq(): supportive functions, will call vhost_vdpa helpers. Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com> Suggested-by: Jason Wang <jasowang@redhat.com> --- drivers/vdpa/vdpa.c | 42 ++++++++++++++++++++++++++++++++++++++++++ include/linux/vdpa.h | 13 +++++++++++++ 2 files changed, 55 insertions(+)