| Message ID | 1592280528-6350-4-git-send-email-yilun.xu@intel.com (mailing list archive) |
|---|---|
| State | Mainlined, archived |
| Headers | show |
| Series | Add interrupt support to FPGA DFL drivers | expand |
On Tue, Jun 16, 2020 at 12:08:44PM +0800, Xu Yilun wrote: > FPGA user applications may be interested in interrupts generated by > DFL features. For example, users can implement their own FPGA > logics with interrupts enabled in AFU (Accelerated Function Unit, > dynamic region of DFL based FPGA). So user applications need to be > notified to handle these interrupts. > > In order to allow userspace applications to monitor interrupts, > driver requires userspace to provide eventfds as interrupt > notification channels. Applications then poll/select on the eventfds > to get notified. > > This patch introduces a generic helper functions to do eventfds binding > with given interrupts. > > Sub feature drivers are expected to use XXX_GET_IRQ_NUM to query irq > info, and XXX_SET_IRQ to set eventfds for interrupts. This patch also > introduces helper functions for these 2 ioctls. > > Signed-off-by: Luwei Kang <luwei.kang@intel.com> > Signed-off-by: Wu Hao <hao.wu@intel.com> > Signed-off-by: Xu Yilun <yilun.xu@intel.com> > Signed-off-by: Tom Rix <trix@redhat.com> > Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com> > Acked-by: Wu Hao <hao.wu@intel.com> > --- > v2: use unsigned int instead of int for irq array indexes in > dfl_fpga_set_irq_triggers() > Improves comments for NULL fds param in dfl_fpga_set_irq_triggers() > v3: Improve comments of dfl_fpga_set_irq_triggers() > refines code for dfl_fpga_set_irq_triggers, delete local variable j > v4: Introduce 2 helper functions to help handle the XXX_GET_IRQ_NUM & > XXX_SET_IRQ ioctls for sub feature drivers. > v5: Some minor fix for Hao's comments > v6: Remove unnecessary type casting > v7: Split the check and wrap the overflow check with the unlikely macro > for dfl_fpga_set_irq_triggers() > remove the redunant check in do_set_irq_trigger() > --- > drivers/fpga/dfl.c | 157 ++++++++++++++++++++++++++++++++++++++++++ > drivers/fpga/dfl.h | 16 +++++ > include/uapi/linux/fpga-dfl.h | 13 ++++ > 3 files changed, 186 insertions(+) > > diff --git a/drivers/fpga/dfl.c b/drivers/fpga/dfl.c > index 02c1ec4..b51db80 100644 > --- a/drivers/fpga/dfl.c > +++ b/drivers/fpga/dfl.c > @@ -10,7 +10,9 @@ > * Wu Hao <hao.wu@intel.com> > * Xiao Guangrong <guangrong.xiao@linux.intel.com> > */ > +#include <linux/fpga-dfl.h> > #include <linux/module.h> > +#include <linux/uaccess.h> > > #include "dfl.h" > > @@ -534,6 +536,7 @@ static int build_info_commit_dev(struct build_feature_devs_info *binfo) > unsigned int i; > > /* save resource information for each feature */ > + feature->dev = fdev; > feature->id = finfo->fid; > feature->resource_index = index; > feature->ioaddr = finfo->ioaddr; > @@ -1394,6 +1397,160 @@ int dfl_fpga_cdev_config_ports_vf(struct dfl_fpga_cdev *cdev, int num_vfs) > } > EXPORT_SYMBOL_GPL(dfl_fpga_cdev_config_ports_vf); > > +static irqreturn_t dfl_irq_handler(int irq, void *arg) > +{ > + struct eventfd_ctx *trigger = arg; > + > + eventfd_signal(trigger, 1); > + return IRQ_HANDLED; > +} > + > +static int do_set_irq_trigger(struct dfl_feature *feature, unsigned int idx, > + int fd) > +{ > + struct platform_device *pdev = feature->dev; > + struct eventfd_ctx *trigger; > + int irq, ret; > + > + irq = feature->irq_ctx[idx].irq; > + > + if (feature->irq_ctx[idx].trigger) { > + free_irq(irq, feature->irq_ctx[idx].trigger); > + kfree(feature->irq_ctx[idx].name); > + eventfd_ctx_put(feature->irq_ctx[idx].trigger); > + feature->irq_ctx[idx].trigger = NULL; > + } > + > + if (fd < 0) > + return 0; > + > + feature->irq_ctx[idx].name = > + kasprintf(GFP_KERNEL, "fpga-irq[%u](%s-%llx)", idx, > + dev_name(&pdev->dev), feature->id); > + if (!feature->irq_ctx[idx].name) > + return -ENOMEM; > + > + trigger = eventfd_ctx_fdget(fd); > + if (IS_ERR(trigger)) { > + ret = PTR_ERR(trigger); > + goto free_name; > + } > + > + ret = request_irq(irq, dfl_irq_handler, 0, > + feature->irq_ctx[idx].name, trigger); > + if (!ret) { > + feature->irq_ctx[idx].trigger = trigger; > + return ret; > + } > + > + eventfd_ctx_put(trigger); > +free_name: > + kfree(feature->irq_ctx[idx].name); > + > + return ret; > +} > + > +/** > + * dfl_fpga_set_irq_triggers - set eventfd triggers for dfl feature interrupts > + * > + * @feature: dfl sub feature. > + * @start: start of irq index in this dfl sub feature. > + * @count: number of irqs. > + * @fds: eventfds to bind with irqs. unbind related irq if fds[n] is negative. > + * unbind "count" specified number of irqs if fds ptr is NULL. > + * > + * Bind given eventfds with irqs in this dfl sub feature. Unbind related irq if > + * fds[n] is negative. Unbind "count" specified number of irqs if fds ptr is > + * NULL. > + * > + * Return: 0 on success, negative error code otherwise. > + */ > +int dfl_fpga_set_irq_triggers(struct dfl_feature *feature, unsigned int start, > + unsigned int count, int32_t *fds) > +{ > + unsigned int i; > + int ret = 0; > + > + /* overflow */ > + if (unlikely(start + count < start)) > + return -EINVAL; > + > + /* exceeds nr_irqs */ > + if (start + count > feature->nr_irqs) > + return -EINVAL; > + > + for (i = 0; i < count; i++) { > + int fd = fds ? fds[i] : -1; > + > + ret = do_set_irq_trigger(feature, start + i, fd); > + if (ret) { > + while (i--) > + do_set_irq_trigger(feature, start + i, -1); > + break; > + } > + } > + > + return ret; > +} > +EXPORT_SYMBOL_GPL(dfl_fpga_set_irq_triggers); > + > +/** > + * dfl_feature_ioctl_get_num_irqs - dfl feature _GET_IRQ_NUM ioctl interface. > + * @pdev: the feature device which has the sub feature > + * @feature: the dfl sub feature > + * @arg: ioctl argument > + * > + * Return: 0 on success, negative error code otherwise. > + */ > +long dfl_feature_ioctl_get_num_irqs(struct platform_device *pdev, > + struct dfl_feature *feature, > + unsigned long arg) > +{ > + return put_user(feature->nr_irqs, (__u32 __user *)arg); > +} > +EXPORT_SYMBOL_GPL(dfl_feature_ioctl_get_num_irqs); > + > +/** > + * dfl_feature_ioctl_set_irq - dfl feature _SET_IRQ ioctl interface. > + * @pdev: the feature device which has the sub feature > + * @feature: the dfl sub feature > + * @arg: ioctl argument > + * > + * Return: 0 on success, negative error code otherwise. > + */ > +long dfl_feature_ioctl_set_irq(struct platform_device *pdev, > + struct dfl_feature *feature, > + unsigned long arg) > +{ > + struct dfl_feature_platform_data *pdata = dev_get_platdata(&pdev->dev); > + struct dfl_fpga_irq_set hdr; > + s32 *fds; > + long ret; > + > + if (!feature->nr_irqs) > + return -ENOENT; > + > + if (copy_from_user(&hdr, (void __user *)arg, sizeof(hdr))) > + return -EFAULT; > + > + if (!hdr.count || (hdr.start + hdr.count > feature->nr_irqs) || > + (hdr.start + hdr.count < hdr.start)) > + return -EINVAL; > + > + fds = memdup_user((void __user *)(arg + sizeof(hdr)), > + hdr.count * sizeof(s32)); > + if (IS_ERR(fds)) > + return PTR_ERR(fds); > + > + mutex_lock(&pdata->lock); > + ret = dfl_fpga_set_irq_triggers(feature, hdr.start, hdr.count, fds); > + mutex_unlock(&pdata->lock); > + > + kfree(fds); > + return ret; > +} > +EXPORT_SYMBOL_GPL(dfl_feature_ioctl_set_irq); > + > static void __exit dfl_fpga_exit(void) > { > dfl_chardev_uinit(); > diff --git a/drivers/fpga/dfl.h b/drivers/fpga/dfl.h > index 59e26f7..632e733 100644 > --- a/drivers/fpga/dfl.h > +++ b/drivers/fpga/dfl.h > @@ -17,6 +17,7 @@ > #include <linux/bitfield.h> > #include <linux/cdev.h> > #include <linux/delay.h> > +#include <linux/eventfd.h> > #include <linux/fs.h> > #include <linux/interrupt.h> > #include <linux/iopoll.h> > @@ -214,14 +215,19 @@ struct dfl_feature_driver { > * struct dfl_feature_irq_ctx - dfl private feature interrupt context > * > * @irq: Linux IRQ number of this interrupt. > + * @trigger: eventfd context to signal when interrupt happens. > + * @name: irq name needed when requesting irq. > */ > struct dfl_feature_irq_ctx { > int irq; > + struct eventfd_ctx *trigger; > + char *name; > }; > > /** > * struct dfl_feature - sub feature of the feature devices > * > + * @dev: ptr to pdev of the feature device which has the sub feature. > * @id: sub feature id. > * @resource_index: each sub feature has one mmio resource for its registers. > * this index is used to find its mmio resource from the > @@ -233,6 +239,7 @@ struct dfl_feature_irq_ctx { > * @priv: priv data of this feature. > */ > struct dfl_feature { > + struct platform_device *dev; > u64 id; > int resource_index; > void __iomem *ioaddr; > @@ -509,4 +516,13 @@ int dfl_fpga_cdev_release_port(struct dfl_fpga_cdev *cdev, int port_id); > int dfl_fpga_cdev_assign_port(struct dfl_fpga_cdev *cdev, int port_id); > void dfl_fpga_cdev_config_ports_pf(struct dfl_fpga_cdev *cdev); > int dfl_fpga_cdev_config_ports_vf(struct dfl_fpga_cdev *cdev, int num_vf); > +int dfl_fpga_set_irq_triggers(struct dfl_feature *feature, unsigned int start, > + unsigned int count, int32_t *fds); > +long dfl_feature_ioctl_get_num_irqs(struct platform_device *pdev, > + struct dfl_feature *feature, > + unsigned long arg); > +long dfl_feature_ioctl_set_irq(struct platform_device *pdev, > + struct dfl_feature *feature, > + unsigned long arg); > + > #endif /* __FPGA_DFL_H */ > diff --git a/include/uapi/linux/fpga-dfl.h b/include/uapi/linux/fpga-dfl.h > index ec70a0746..7331350 100644 > --- a/include/uapi/linux/fpga-dfl.h > +++ b/include/uapi/linux/fpga-dfl.h > @@ -151,6 +151,19 @@ struct dfl_fpga_port_dma_unmap { > > #define DFL_FPGA_PORT_DMA_UNMAP _IO(DFL_FPGA_MAGIC, DFL_PORT_BASE + 4) > > +/** > + * struct dfl_fpga_irq_set - the argument for DFL_FPGA_XXX_SET_IRQ ioctl. > + * > + * @start: Index of the first irq. > + * @count: The number of eventfd handler. > + * @evtfds: Eventfd handlers. > + */ > +struct dfl_fpga_irq_set { > + __u32 start; > + __u32 count; > + __s32 evtfds[]; > +}; > + > /* IOCTLs for FME file descriptor */ > > /** > -- > 2.7.4 > Applied to for-next, Thanks!
diff --git a/drivers/fpga/dfl.c b/drivers/fpga/dfl.c index 02c1ec4..b51db80 100644 --- a/drivers/fpga/dfl.c +++ b/drivers/fpga/dfl.c @@ -10,7 +10,9 @@ * Wu Hao <hao.wu@intel.com> * Xiao Guangrong <guangrong.xiao@linux.intel.com> */ +#include <linux/fpga-dfl.h> #include <linux/module.h> +#include <linux/uaccess.h> #include "dfl.h" @@ -534,6 +536,7 @@ static int build_info_commit_dev(struct build_feature_devs_info *binfo) unsigned int i; /* save resource information for each feature */ + feature->dev = fdev; feature->id = finfo->fid; feature->resource_index = index; feature->ioaddr = finfo->ioaddr; @@ -1394,6 +1397,160 @@ int dfl_fpga_cdev_config_ports_vf(struct dfl_fpga_cdev *cdev, int num_vfs) } EXPORT_SYMBOL_GPL(dfl_fpga_cdev_config_ports_vf); +static irqreturn_t dfl_irq_handler(int irq, void *arg) +{ + struct eventfd_ctx *trigger = arg; + + eventfd_signal(trigger, 1); + return IRQ_HANDLED; +} + +static int do_set_irq_trigger(struct dfl_feature *feature, unsigned int idx, + int fd) +{ + struct platform_device *pdev = feature->dev; + struct eventfd_ctx *trigger; + int irq, ret; + + irq = feature->irq_ctx[idx].irq; + + if (feature->irq_ctx[idx].trigger) { + free_irq(irq, feature->irq_ctx[idx].trigger); + kfree(feature->irq_ctx[idx].name); + eventfd_ctx_put(feature->irq_ctx[idx].trigger); + feature->irq_ctx[idx].trigger = NULL; + } + + if (fd < 0) + return 0; + + feature->irq_ctx[idx].name = + kasprintf(GFP_KERNEL, "fpga-irq[%u](%s-%llx)", idx, + dev_name(&pdev->dev), feature->id); + if (!feature->irq_ctx[idx].name) + return -ENOMEM; + + trigger = eventfd_ctx_fdget(fd); + if (IS_ERR(trigger)) { + ret = PTR_ERR(trigger); + goto free_name; + } + + ret = request_irq(irq, dfl_irq_handler, 0, + feature->irq_ctx[idx].name, trigger); + if (!ret) { + feature->irq_ctx[idx].trigger = trigger; + return ret; + } + + eventfd_ctx_put(trigger); +free_name: + kfree(feature->irq_ctx[idx].name); + + return ret; +} + +/** + * dfl_fpga_set_irq_triggers - set eventfd triggers for dfl feature interrupts + * + * @feature: dfl sub feature. + * @start: start of irq index in this dfl sub feature. + * @count: number of irqs. + * @fds: eventfds to bind with irqs. unbind related irq if fds[n] is negative. + * unbind "count" specified number of irqs if fds ptr is NULL. + * + * Bind given eventfds with irqs in this dfl sub feature. Unbind related irq if + * fds[n] is negative. Unbind "count" specified number of irqs if fds ptr is + * NULL. + * + * Return: 0 on success, negative error code otherwise. + */ +int dfl_fpga_set_irq_triggers(struct dfl_feature *feature, unsigned int start, + unsigned int count, int32_t *fds) +{ + unsigned int i; + int ret = 0; + + /* overflow */ + if (unlikely(start + count < start)) + return -EINVAL; + + /* exceeds nr_irqs */ + if (start + count > feature->nr_irqs) + return -EINVAL; + + for (i = 0; i < count; i++) { + int fd = fds ? fds[i] : -1; + + ret = do_set_irq_trigger(feature, start + i, fd); + if (ret) { + while (i--) + do_set_irq_trigger(feature, start + i, -1); + break; + } + } + + return ret; +} +EXPORT_SYMBOL_GPL(dfl_fpga_set_irq_triggers); + +/** + * dfl_feature_ioctl_get_num_irqs - dfl feature _GET_IRQ_NUM ioctl interface. + * @pdev: the feature device which has the sub feature + * @feature: the dfl sub feature + * @arg: ioctl argument + * + * Return: 0 on success, negative error code otherwise. + */ +long dfl_feature_ioctl_get_num_irqs(struct platform_device *pdev, + struct dfl_feature *feature, + unsigned long arg) +{ + return put_user(feature->nr_irqs, (__u32 __user *)arg); +} +EXPORT_SYMBOL_GPL(dfl_feature_ioctl_get_num_irqs); + +/** + * dfl_feature_ioctl_set_irq - dfl feature _SET_IRQ ioctl interface. + * @pdev: the feature device which has the sub feature + * @feature: the dfl sub feature + * @arg: ioctl argument + * + * Return: 0 on success, negative error code otherwise. + */ +long dfl_feature_ioctl_set_irq(struct platform_device *pdev, + struct dfl_feature *feature, + unsigned long arg) +{ + struct dfl_feature_platform_data *pdata = dev_get_platdata(&pdev->dev); + struct dfl_fpga_irq_set hdr; + s32 *fds; + long ret; + + if (!feature->nr_irqs) + return -ENOENT; + + if (copy_from_user(&hdr, (void __user *)arg, sizeof(hdr))) + return -EFAULT; + + if (!hdr.count || (hdr.start + hdr.count > feature->nr_irqs) || + (hdr.start + hdr.count < hdr.start)) + return -EINVAL; + + fds = memdup_user((void __user *)(arg + sizeof(hdr)), + hdr.count * sizeof(s32)); + if (IS_ERR(fds)) + return PTR_ERR(fds); + + mutex_lock(&pdata->lock); + ret = dfl_fpga_set_irq_triggers(feature, hdr.start, hdr.count, fds); + mutex_unlock(&pdata->lock); + + kfree(fds); + return ret; +} +EXPORT_SYMBOL_GPL(dfl_feature_ioctl_set_irq); + static void __exit dfl_fpga_exit(void) { dfl_chardev_uinit(); diff --git a/drivers/fpga/dfl.h b/drivers/fpga/dfl.h index 59e26f7..632e733 100644 --- a/drivers/fpga/dfl.h +++ b/drivers/fpga/dfl.h @@ -17,6 +17,7 @@ #include <linux/bitfield.h> #include <linux/cdev.h> #include <linux/delay.h> +#include <linux/eventfd.h> #include <linux/fs.h> #include <linux/interrupt.h> #include <linux/iopoll.h> @@ -214,14 +215,19 @@ struct dfl_feature_driver { * struct dfl_feature_irq_ctx - dfl private feature interrupt context * * @irq: Linux IRQ number of this interrupt. + * @trigger: eventfd context to signal when interrupt happens. + * @name: irq name needed when requesting irq. */ struct dfl_feature_irq_ctx { int irq; + struct eventfd_ctx *trigger; + char *name; }; /** * struct dfl_feature - sub feature of the feature devices * + * @dev: ptr to pdev of the feature device which has the sub feature. * @id: sub feature id. * @resource_index: each sub feature has one mmio resource for its registers. * this index is used to find its mmio resource from the @@ -233,6 +239,7 @@ struct dfl_feature_irq_ctx { * @priv: priv data of this feature. */ struct dfl_feature { + struct platform_device *dev; u64 id; int resource_index; void __iomem *ioaddr; @@ -509,4 +516,13 @@ int dfl_fpga_cdev_release_port(struct dfl_fpga_cdev *cdev, int port_id); int dfl_fpga_cdev_assign_port(struct dfl_fpga_cdev *cdev, int port_id); void dfl_fpga_cdev_config_ports_pf(struct dfl_fpga_cdev *cdev); int dfl_fpga_cdev_config_ports_vf(struct dfl_fpga_cdev *cdev, int num_vf); +int dfl_fpga_set_irq_triggers(struct dfl_feature *feature, unsigned int start, + unsigned int count, int32_t *fds); +long dfl_feature_ioctl_get_num_irqs(struct platform_device *pdev, + struct dfl_feature *feature, + unsigned long arg); +long dfl_feature_ioctl_set_irq(struct platform_device *pdev, + struct dfl_feature *feature, + unsigned long arg); + #endif /* __FPGA_DFL_H */ diff --git a/include/uapi/linux/fpga-dfl.h b/include/uapi/linux/fpga-dfl.h index ec70a0746..7331350 100644 --- a/include/uapi/linux/fpga-dfl.h +++ b/include/uapi/linux/fpga-dfl.h @@ -151,6 +151,19 @@ struct dfl_fpga_port_dma_unmap { #define DFL_FPGA_PORT_DMA_UNMAP _IO(DFL_FPGA_MAGIC, DFL_PORT_BASE + 4) +/** + * struct dfl_fpga_irq_set - the argument for DFL_FPGA_XXX_SET_IRQ ioctl. + * + * @start: Index of the first irq. + * @count: The number of eventfd handler. + * @evtfds: Eventfd handlers. + */ +struct dfl_fpga_irq_set { + __u32 start; + __u32 count; + __s32 evtfds[]; +}; + /* IOCTLs for FME file descriptor */ /**