On Sun, Feb 14, 2021 at 4:02 PM Alexandru Ardelean <ardeleanalex@xxxxxxxxx> wrote: > > On Sun, Feb 14, 2021 at 3:21 PM Jonathan Cameron <jic23@xxxxxxxxxx> wrote: > > > > On Thu, 11 Feb 2021 14:24:47 +0200 > > Alexandru Ardelean <alexandru.ardelean@xxxxxxxxxx> wrote: > > > > > With this change, calling iio_device_attach_buffer() will actually attach > > > more buffers. > > > Right now this doesn't do any validation of whether a buffer is attached > > > twice; maybe that can be added later (if needed). Attaching a buffer more > > > than once should yield noticeably bad results. > > > > > > The first buffer is the legacy buffer, so a reference is kept to it. > > > > > > At this point, accessing the data for the extra buffers (that are added > > > after the first one) isn't possible yet. > > > > > > The iio_device_attach_buffer() is also changed to return an error code, > > > which for now is -ENOMEM if the array could not be realloc-ed for more > > > buffers. > > > > This is called from a bunch of places, so we need to add error handling > > for those which isn't currently present. > > > > Now arguably it is unlikely to fail, so I'm not that bothered about seeing > > them all in place as part of this series, but I would like the handling > > to have been posted at least. > > I know what you're referring to. > I have a slightly better approach before updating this. > I was going to send it a little later. > I wanted to send it earlier, but I wanted to avoid overlapping myself > with too many patches. > Let me send something now [since it is ready]. So, coming back here. See series [1]: https://lore.kernel.org/linux-iio/20210214143313.67202-1-alexandru.ardelean@xxxxxxxxxx/T/#t I could probably re-spin this series on top of series [1]. That would make things cleaner in terms of handling iio_device_attach_buffer() in just 2 places I think. > > > > > Otherwise, a few passing comments in here, but nothing to actually change. > > > > > > Jonathan > > > > > > > > Signed-off-by: Alexandru Ardelean <alexandru.ardelean@xxxxxxxxxx> > > > --- > > > drivers/iio/iio_core.h | 2 + > > > drivers/iio/industrialio-buffer.c | 96 +++++++++++++++++++++++++------ > > > drivers/iio/industrialio-core.c | 6 +- > > > include/linux/iio/buffer.h | 4 +- > > > include/linux/iio/buffer_impl.h | 3 + > > > include/linux/iio/iio-opaque.h | 4 ++ > > > 6 files changed, 93 insertions(+), 22 deletions(-) > > > > > > diff --git a/drivers/iio/iio_core.h b/drivers/iio/iio_core.h > > > index 87868fff7d37..4690c3240a5d 100644 > > > --- a/drivers/iio/iio_core.h > > > +++ b/drivers/iio/iio_core.h > > > @@ -77,6 +77,7 @@ void iio_buffer_free_sysfs_and_mask(struct iio_dev *indio_dev); > > > > > > void iio_disable_all_buffers(struct iio_dev *indio_dev); > > > void iio_buffer_wakeup_poll(struct iio_dev *indio_dev); > > > +void iio_buffers_put(struct iio_dev *indio_dev); > > > > > > #else > > > > > > @@ -92,6 +93,7 @@ static inline void iio_buffer_free_sysfs_and_mask(struct iio_dev *indio_dev) {} > > > > > > static inline void iio_disable_all_buffers(struct iio_dev *indio_dev) {} > > > static inline void iio_buffer_wakeup_poll(struct iio_dev *indio_dev) {} > > > +static inline void iio_buffers_put(struct iio_dev *indio_dev) {} > > > > > > #endif > > > > > > diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c > > > index 209b3a32bdbb..1e8e4c2ff00e 100644 > > > --- a/drivers/iio/industrialio-buffer.c > > > +++ b/drivers/iio/industrialio-buffer.c > > > @@ -193,12 +193,14 @@ __poll_t iio_buffer_poll(struct file *filp, > > > */ > > > void iio_buffer_wakeup_poll(struct iio_dev *indio_dev) > > > { > > > - struct iio_buffer *buffer = indio_dev->buffer; > > > - > > > - if (!buffer) > > > - return; > > > + struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev); > > > + struct iio_buffer *buffer; > > > + unsigned int i; > > > > > > - wake_up(&buffer->pollq); > > > + for (i = 0; i < iio_dev_opaque->attached_buffers_cnt; i++) { > > > + buffer = iio_dev_opaque->attached_buffers[i]; > > > + wake_up(&buffer->pollq); > > > + } > > > } > > > > > > void iio_buffer_init(struct iio_buffer *buffer) > > > @@ -212,6 +214,18 @@ void iio_buffer_init(struct iio_buffer *buffer) > > > } > > > EXPORT_SYMBOL(iio_buffer_init); > > > > > > +void iio_buffers_put(struct iio_dev *indio_dev) > > > +{ > > > + struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev); > > > + struct iio_buffer *buffer; > > > + unsigned int i; > > > + > > > + for (i = 0; i < iio_dev_opaque->attached_buffers_cnt; i++) { > > > + buffer = iio_dev_opaque->attached_buffers[i]; > > > + iio_buffer_put(buffer); > > > + } > > > +} > > > + > > > static ssize_t iio_show_scan_index(struct device *dev, > > > struct device_attribute *attr, > > > char *buf) > > > @@ -1453,9 +1467,11 @@ static void __iio_buffer_free_sysfs_and_mask(struct iio_buffer *buffer) > > > > > > int iio_buffer_alloc_sysfs_and_mask(struct iio_dev *indio_dev) > > > { > > > - struct iio_buffer *buffer = indio_dev->buffer; > > > + struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev); > > > const struct iio_chan_spec *channels; > > > - int i; > > > + struct iio_buffer *buffer; > > > + int unwind_idx; > > > + int ret, i; > > > > > > channels = indio_dev->channels; > > > if (channels) { > > > @@ -1466,22 +1482,46 @@ int iio_buffer_alloc_sysfs_and_mask(struct iio_dev *indio_dev) > > > indio_dev->masklength = ml; > > > } > > > > > > - if (!buffer) > > > + if (!iio_dev_opaque->attached_buffers_cnt) > > > return 0; > > > > > > - return __iio_buffer_alloc_sysfs_and_mask(buffer, indio_dev, 0); > > > + for (i = 0; i < iio_dev_opaque->attached_buffers_cnt; i++) { > > > + buffer = iio_dev_opaque->attached_buffers[i]; > > > + ret = __iio_buffer_alloc_sysfs_and_mask(buffer, indio_dev, i); > > > + if (ret) { > > > + unwind_idx = i; > > > + goto error_unwind_sysfs_and_mask; > > > + } > > > + } > > > + > > > + return 0; > > > + > > > +error_unwind_sysfs_and_mask: > > > + for (; unwind_idx >= 0; unwind_idx--) { > > > + buffer = iio_dev_opaque->attached_buffers[unwind_idx]; > > > + __iio_buffer_free_sysfs_and_mask(buffer); > > > + } > > > + kfree(iio_dev_opaque->attached_buffers); > > > + return ret; > > > } > > > > > > void iio_buffer_free_sysfs_and_mask(struct iio_dev *indio_dev) > > > { > > > > Perhaps we should do a follow up adjusting names to slightly better > > reflect they are not handling multiple buffers. > > > > > - struct iio_buffer *buffer = indio_dev->buffer; > > > + struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev); > > > + struct iio_buffer *buffer; > > > + int i; > > > > > > - if (!buffer) > > > + if (!iio_dev_opaque->attached_buffers_cnt) > > > return; > > > > > > iio_buffer_unregister_legacy_sysfs_groups(indio_dev); > > > > > > - __iio_buffer_free_sysfs_and_mask(buffer); > > > + for (i = iio_dev_opaque->attached_buffers_cnt - 1; i >= 0; i--) { > > > + buffer = iio_dev_opaque->attached_buffers[i]; > > > + __iio_buffer_free_sysfs_and_mask(buffer); > > > + } > > > + > > > + kfree(iio_dev_opaque->attached_buffers); > > > > Hmm. This does feel like it's in slightly the wrong place, but > > I'm not sure where it actually should be. > > > > Given this is the last element in the call sequence I guess it doesn't > > makes sense to bring in another function just to tidy up this connection. > > > > > } > > > > > > /** > > > @@ -1599,13 +1639,35 @@ EXPORT_SYMBOL_GPL(iio_buffer_put); > > > * @indio_dev: The device the buffer should be attached to > > > * @buffer: The buffer to attach to the device > > > * > > > + * Return 0 if successful, negative if error. > > > + * > > > * This function attaches a buffer to a IIO device. The buffer stays attached to > > > - * the device until the device is freed. The function should only be called at > > > - * most once per device. > > > + * the device until the device is freed. For legacy reasons, the first attached > > > + * buffer will also be assigned to 'indio_dev->buffer'. > > > */ > > > -void iio_device_attach_buffer(struct iio_dev *indio_dev, > > > - struct iio_buffer *buffer) > > > +int iio_device_attach_buffer(struct iio_dev *indio_dev, > > > + struct iio_buffer *buffer) > > > { > > > - indio_dev->buffer = iio_buffer_get(buffer); > > > + struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev); > > > + struct iio_buffer **new, **old = iio_dev_opaque->attached_buffers; > > > + unsigned int cnt = iio_dev_opaque->attached_buffers_cnt; > > > + > > > + cnt++; > > > + > > > + new = krealloc(old, sizeof(*new) * cnt, GFP_KERNEL); > > > + if (!new) > > > + return -ENOMEM; > > > + iio_dev_opaque->attached_buffers = new; > > > + > > > + buffer = iio_buffer_get(buffer); > > > + > > > + /* first buffer is legacy; attach it to the IIO device directly */ > > > + if (!indio_dev->buffer) > > > + indio_dev->buffer = buffer; > > > + > > > + iio_dev_opaque->attached_buffers[cnt - 1] = buffer; > > > + iio_dev_opaque->attached_buffers_cnt = cnt; > > > + > > > + return 0; > > > } > > > EXPORT_SYMBOL_GPL(iio_device_attach_buffer); > > > diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c > > > index 1be94df3e591..26b05dddfa71 100644 > > > --- a/drivers/iio/industrialio-core.c > > > +++ b/drivers/iio/industrialio-core.c > > > @@ -1583,7 +1583,7 @@ static void iio_dev_release(struct device *device) > > > iio_device_unregister_eventset(indio_dev); > > > iio_device_unregister_sysfs(indio_dev); > > > > > > - iio_buffer_put(indio_dev->buffer); > > > + iio_buffers_put(indio_dev); > > > > > > ida_simple_remove(&iio_ida, indio_dev->id); > > > kfree(iio_dev_opaque); > > > @@ -1884,12 +1884,12 @@ int __iio_device_register(struct iio_dev *indio_dev, struct module *this_mod) > > > indio_dev->setup_ops == NULL) > > > indio_dev->setup_ops = &noop_ring_setup_ops; > > > > > > - if (indio_dev->buffer) > > > + if (iio_dev_opaque->attached_buffers_cnt) > > > cdev_init(&indio_dev->chrdev, &iio_buffer_fileops); > > > else if (iio_dev_opaque->event_interface) > > > cdev_init(&indio_dev->chrdev, &iio_event_fileops); > > > > > > - if (indio_dev->buffer || iio_dev_opaque->event_interface) { > > > + if (iio_dev_opaque->attached_buffers_cnt || iio_dev_opaque->event_interface) { > > > indio_dev->dev.devt = MKDEV(MAJOR(iio_devt), indio_dev->id); > > > indio_dev->chrdev.owner = this_mod; > > > } > > > diff --git a/include/linux/iio/buffer.h b/include/linux/iio/buffer.h > > > index 8febc23f5f26..b6928ac5c63d 100644 > > > --- a/include/linux/iio/buffer.h > > > +++ b/include/linux/iio/buffer.h > > > @@ -41,7 +41,7 @@ static inline int iio_push_to_buffers_with_timestamp(struct iio_dev *indio_dev, > > > bool iio_validate_scan_mask_onehot(struct iio_dev *indio_dev, > > > const unsigned long *mask); > > > > > > -void iio_device_attach_buffer(struct iio_dev *indio_dev, > > > - struct iio_buffer *buffer); > > > +int iio_device_attach_buffer(struct iio_dev *indio_dev, > > > + struct iio_buffer *buffer); > > > > > > #endif /* _IIO_BUFFER_GENERIC_H_ */ > > > diff --git a/include/linux/iio/buffer_impl.h b/include/linux/iio/buffer_impl.h > > > index 41044320e581..768b90c64412 100644 > > > --- a/include/linux/iio/buffer_impl.h > > > +++ b/include/linux/iio/buffer_impl.h > > > @@ -112,6 +112,9 @@ struct iio_buffer { > > > /* @demux_bounce: Buffer for doing gather from incoming scan. */ > > > void *demux_bounce; > > > > > > + /* @attached_entry: Entry in the devices list of buffers attached by the driver. */ > > > + struct list_head attached_entry; > > > + > > > /* @buffer_list: Entry in the devices list of current buffers. */ > > > struct list_head buffer_list; > > > > > > diff --git a/include/linux/iio/iio-opaque.h b/include/linux/iio/iio-opaque.h > > > index 3e4c3cd248fd..c909835b6247 100644 > > > --- a/include/linux/iio/iio-opaque.h > > > +++ b/include/linux/iio/iio-opaque.h > > > @@ -7,6 +7,8 @@ > > > * struct iio_dev_opaque - industrial I/O device opaque information > > > * @indio_dev: public industrial I/O device information > > > * @event_interface: event chrdevs associated with interrupt lines > > > + * @attached_buffers: array of buffers statically attached by the driver > > > + * @attached_buffers_cnt: number of buffers in the array of statically attached buffers > > > * @buffer_list: list of all buffers currently attached > > > * @channel_attr_list: keep track of automatically created channel > > > * attributes > > > @@ -24,6 +26,8 @@ > > > struct iio_dev_opaque { > > > struct iio_dev indio_dev; > > > struct iio_event_interface *event_interface; > > > + struct iio_buffer **attached_buffers; > > > + unsigned int attached_buffers_cnt; > > > struct list_head buffer_list; > > > struct list_head channel_attr_list; > > > struct attribute_group chan_attr_group; > >
