| Message ID | 20201117162340.43924-12-alexandru.ardelean@analog.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [RFC,01/12] iio: core: register chardev only if needed | expand |
On Tue, 17 Nov 2020 18:23:39 +0200 Alexandru Ardelean <alexandru.ardelean@analog.com> 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. > > Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com> A couple of minor things in here.. Jonathan > --- > drivers/iio/industrialio-buffer.c | 58 +++++++++++++++++++++++++------ > include/linux/iio/buffer_impl.h | 3 ++ > include/linux/iio/iio-opaque.h | 4 +++ > 3 files changed, 54 insertions(+), 11 deletions(-) > > diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c > index c83cec89eddf..daa68822cea7 100644 > --- a/drivers/iio/industrialio-buffer.c > +++ b/drivers/iio/industrialio-buffer.c > @@ -1513,6 +1513,7 @@ 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_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev); > struct iio_buffer *buffer = indio_dev->buffer; > const struct iio_chan_spec *channels; > int i, ret; > @@ -1529,15 +1530,18 @@ int iio_buffer_alloc_sysfs_and_mask(struct iio_dev *indio_dev) > if (!buffer) > return 0; > > - ret = __iio_buffer_alloc_sysfs_and_mask(buffer, indio_dev, 0); > - if (ret) > - return ret; > + 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) > + goto error_unwind_sysfs_and_mask; > + } > > ret = sysfs_create_link(&indio_dev->dev.kobj, > &indio_dev->buffer->buffer_dir, > "buffer"); > if (ret) > - goto error_free_sysfs_and_mask; > + goto error_unwind_sysfs_and_mask; > > ret = sysfs_create_link(&indio_dev->dev.kobj, > &indio_dev->buffer->scan_el_dir, > @@ -1549,8 +1553,14 @@ int iio_buffer_alloc_sysfs_and_mask(struct iio_dev *indio_dev) > > error_remove_buffer_dir_link: > sysfs_remove_link(&indio_dev->dev.kobj, "buffer"); > -error_free_sysfs_and_mask: > - __iio_buffer_free_sysfs_and_mask(buffer); > + i = iio_dev_opaque->attached_buffers_cnt - 1; Perhaps just use a counter variable that is only for this then you won't need to set it again in this error path. > +error_unwind_sysfs_and_mask: > + for (; i >= 0; i--) { > + buffer = iio_dev_opaque->attached_buffers[i]; > + __iio_buffer_free_sysfs_and_mask(buffer); > + } > + kfree(iio_dev_opaque->attached_buffers); > + iio_dev_opaque->attached_buffers = NULL; > return ret; > } > > @@ -1568,7 +1578,9 @@ static void __iio_buffer_free_sysfs_and_mask(struct iio_buffer *buffer) > > void iio_buffer_free_sysfs_and_mask(struct iio_dev *indio_dev) > { > + struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev); > struct iio_buffer *buffer = indio_dev->buffer; > + int i; > > if (!buffer) > return; > @@ -1576,7 +1588,13 @@ void iio_buffer_free_sysfs_and_mask(struct iio_dev *indio_dev) > sysfs_remove_link(&indio_dev->dev.kobj, "scan_elements"); > sysfs_remove_link(&indio_dev->dev.kobj, "buffer"); > > - __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); > + iio_dev_opaque->attached_buffers = NULL; > } > > /** > @@ -1709,14 +1727,32 @@ EXPORT_SYMBOL_GPL(iio_buffer_get_iio_dev); > * @buffer: The buffer to attach to the device > * > * 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) > { > - 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) { > + kfree(old); Need a comment on why freeing old makes sense. > + return; > + } > + iio_dev_opaque->attached_buffers = new; > + > + /* first buffer is legacy; attach it to the IIO device directly */ > + if (!indio_dev->buffer) > + indio_dev->buffer = iio_buffer_get(buffer); > + > + buffer->indio_dev = indio_dev; > > - indio_dev->buffer->indio_dev = indio_dev; > + iio_dev_opaque->attached_buffers[cnt - 1] = buffer; > + iio_dev_opaque->attached_buffers_cnt = cnt; > } > EXPORT_SYMBOL_GPL(iio_device_attach_buffer); > diff --git a/include/linux/iio/buffer_impl.h b/include/linux/iio/buffer_impl.h > index 77e169e51434..e25d26a7f601 100644 > --- a/include/linux/iio/buffer_impl.h > +++ b/include/linux/iio/buffer_impl.h > @@ -124,6 +124,9 @@ 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 07c5a8e52ca8..1db0ea09520e 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 > @@ -20,6 +22,8 @@ > 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;
On Sat, Nov 21, 2020 at 8:46 PM Jonathan Cameron <jic23@kernel.org> wrote: > > On Tue, 17 Nov 2020 18:23:39 +0200 > Alexandru Ardelean <alexandru.ardelean@analog.com> 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. > > > > Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com> > A couple of minor things in here.. > > Jonathan > > > --- > > drivers/iio/industrialio-buffer.c | 58 +++++++++++++++++++++++++------ > > include/linux/iio/buffer_impl.h | 3 ++ > > include/linux/iio/iio-opaque.h | 4 +++ > > 3 files changed, 54 insertions(+), 11 deletions(-) > > > > diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c > > index c83cec89eddf..daa68822cea7 100644 > > --- a/drivers/iio/industrialio-buffer.c > > +++ b/drivers/iio/industrialio-buffer.c > > @@ -1513,6 +1513,7 @@ 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_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev); > > struct iio_buffer *buffer = indio_dev->buffer; > > const struct iio_chan_spec *channels; > > int i, ret; > > @@ -1529,15 +1530,18 @@ int iio_buffer_alloc_sysfs_and_mask(struct iio_dev *indio_dev) > > if (!buffer) > > return 0; > > > > - ret = __iio_buffer_alloc_sysfs_and_mask(buffer, indio_dev, 0); > > - if (ret) > > - return ret; > > + 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) > > + goto error_unwind_sysfs_and_mask; > > + } > > > > ret = sysfs_create_link(&indio_dev->dev.kobj, > > &indio_dev->buffer->buffer_dir, > > "buffer"); > > if (ret) > > - goto error_free_sysfs_and_mask; > > + goto error_unwind_sysfs_and_mask; > > > > ret = sysfs_create_link(&indio_dev->dev.kobj, > > &indio_dev->buffer->scan_el_dir, > > @@ -1549,8 +1553,14 @@ int iio_buffer_alloc_sysfs_and_mask(struct iio_dev *indio_dev) > > > > error_remove_buffer_dir_link: > > sysfs_remove_link(&indio_dev->dev.kobj, "buffer"); > > -error_free_sysfs_and_mask: > > - __iio_buffer_free_sysfs_and_mask(buffer); > > + i = iio_dev_opaque->attached_buffers_cnt - 1; > > Perhaps just use a counter variable that is only for this then you won't need > to set it again in this error path. Ack. > > > +error_unwind_sysfs_and_mask: > > + for (; i >= 0; i--) { > > + buffer = iio_dev_opaque->attached_buffers[i]; > > + __iio_buffer_free_sysfs_and_mask(buffer); > > + } > > + kfree(iio_dev_opaque->attached_buffers); > > + iio_dev_opaque->attached_buffers = NULL; > > return ret; > > } > > > > @@ -1568,7 +1578,9 @@ static void __iio_buffer_free_sysfs_and_mask(struct iio_buffer *buffer) > > > > void iio_buffer_free_sysfs_and_mask(struct iio_dev *indio_dev) > > { > > + struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev); > > struct iio_buffer *buffer = indio_dev->buffer; > > + int i; > > > > if (!buffer) > > return; > > @@ -1576,7 +1588,13 @@ void iio_buffer_free_sysfs_and_mask(struct iio_dev *indio_dev) > > sysfs_remove_link(&indio_dev->dev.kobj, "scan_elements"); > > sysfs_remove_link(&indio_dev->dev.kobj, "buffer"); > > > > - __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); > > + iio_dev_opaque->attached_buffers = NULL; > > } > > > > /** > > @@ -1709,14 +1727,32 @@ EXPORT_SYMBOL_GPL(iio_buffer_get_iio_dev); > > * @buffer: The buffer to attach to the device > > * > > * 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) > > { > > - 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) { > > + kfree(old); > > Need a comment on why freeing old makes sense. Hmm, maybe here I'd need to change this a bit. I'm seeing a few potential issues. > > > + return; > > + } > > + iio_dev_opaque->attached_buffers = new; > > + > > + /* first buffer is legacy; attach it to the IIO device directly */ > > + if (!indio_dev->buffer) > > + indio_dev->buffer = iio_buffer_get(buffer); > > + > > + buffer->indio_dev = indio_dev; > > > > - indio_dev->buffer->indio_dev = indio_dev; > > + iio_dev_opaque->attached_buffers[cnt - 1] = buffer; > > + iio_dev_opaque->attached_buffers_cnt = cnt; > > } > > EXPORT_SYMBOL_GPL(iio_device_attach_buffer); > > diff --git a/include/linux/iio/buffer_impl.h b/include/linux/iio/buffer_impl.h > > index 77e169e51434..e25d26a7f601 100644 > > --- a/include/linux/iio/buffer_impl.h > > +++ b/include/linux/iio/buffer_impl.h > > @@ -124,6 +124,9 @@ 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 07c5a8e52ca8..1db0ea09520e 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 > > @@ -20,6 +22,8 @@ > > 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; >
diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c index c83cec89eddf..daa68822cea7 100644 --- a/drivers/iio/industrialio-buffer.c +++ b/drivers/iio/industrialio-buffer.c @@ -1513,6 +1513,7 @@ 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_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev); struct iio_buffer *buffer = indio_dev->buffer; const struct iio_chan_spec *channels; int i, ret; @@ -1529,15 +1530,18 @@ int iio_buffer_alloc_sysfs_and_mask(struct iio_dev *indio_dev) if (!buffer) return 0; - ret = __iio_buffer_alloc_sysfs_and_mask(buffer, indio_dev, 0); - if (ret) - return ret; + 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) + goto error_unwind_sysfs_and_mask; + } ret = sysfs_create_link(&indio_dev->dev.kobj, &indio_dev->buffer->buffer_dir, "buffer"); if (ret) - goto error_free_sysfs_and_mask; + goto error_unwind_sysfs_and_mask; ret = sysfs_create_link(&indio_dev->dev.kobj, &indio_dev->buffer->scan_el_dir, @@ -1549,8 +1553,14 @@ int iio_buffer_alloc_sysfs_and_mask(struct iio_dev *indio_dev) error_remove_buffer_dir_link: sysfs_remove_link(&indio_dev->dev.kobj, "buffer"); -error_free_sysfs_and_mask: - __iio_buffer_free_sysfs_and_mask(buffer); + i = iio_dev_opaque->attached_buffers_cnt - 1; +error_unwind_sysfs_and_mask: + for (; i >= 0; i--) { + buffer = iio_dev_opaque->attached_buffers[i]; + __iio_buffer_free_sysfs_and_mask(buffer); + } + kfree(iio_dev_opaque->attached_buffers); + iio_dev_opaque->attached_buffers = NULL; return ret; } @@ -1568,7 +1578,9 @@ static void __iio_buffer_free_sysfs_and_mask(struct iio_buffer *buffer) void iio_buffer_free_sysfs_and_mask(struct iio_dev *indio_dev) { + struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev); struct iio_buffer *buffer = indio_dev->buffer; + int i; if (!buffer) return; @@ -1576,7 +1588,13 @@ void iio_buffer_free_sysfs_and_mask(struct iio_dev *indio_dev) sysfs_remove_link(&indio_dev->dev.kobj, "scan_elements"); sysfs_remove_link(&indio_dev->dev.kobj, "buffer"); - __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); + iio_dev_opaque->attached_buffers = NULL; } /** @@ -1709,14 +1727,32 @@ EXPORT_SYMBOL_GPL(iio_buffer_get_iio_dev); * @buffer: The buffer to attach to the device * * 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) { - 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) { + kfree(old); + return; + } + iio_dev_opaque->attached_buffers = new; + + /* first buffer is legacy; attach it to the IIO device directly */ + if (!indio_dev->buffer) + indio_dev->buffer = iio_buffer_get(buffer); + + buffer->indio_dev = indio_dev; - indio_dev->buffer->indio_dev = indio_dev; + iio_dev_opaque->attached_buffers[cnt - 1] = buffer; + iio_dev_opaque->attached_buffers_cnt = cnt; } EXPORT_SYMBOL_GPL(iio_device_attach_buffer); diff --git a/include/linux/iio/buffer_impl.h b/include/linux/iio/buffer_impl.h index 77e169e51434..e25d26a7f601 100644 --- a/include/linux/iio/buffer_impl.h +++ b/include/linux/iio/buffer_impl.h @@ -124,6 +124,9 @@ 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 07c5a8e52ca8..1db0ea09520e 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 @@ -20,6 +22,8 @@ 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;
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. Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com> --- drivers/iio/industrialio-buffer.c | 58 +++++++++++++++++++++++++------ include/linux/iio/buffer_impl.h | 3 ++ include/linux/iio/iio-opaque.h | 4 +++ 3 files changed, 54 insertions(+), 11 deletions(-)