Re: [PATCH V2 3/6] vDPA: implement IRQ offloading helpers in vDPA core
From: Jason Wang <jasowang@redhat.com>
Date: 2020-07-17 04:19:58
Also in:
kvm, virtualization
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.
quoted hunk ↗ jump to hunk
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 <redacted> 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.
quoted hunk ↗ jump to hunk
+{ + 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) \