| Message ID | 20210211122452.78106-6-alexandru.ardelean@analog.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | iio: core,buffer: add support for multiple IIO buffers per IIO device | expand |
On Thu, 11 Feb 2021 14:24:40 +0200 Alexandru Ardelean <alexandru.ardelean@analog.com> wrote: > If we want to merge the attributes of the buffer/ and scan_elements/ > directories, we'll need to count all attributes first, then (depending on > the attribute group) either allocate 2 attribute groups, or a single one. > Historically an IIO buffer was described by 2 subdirectories under > /sys/bus/iio/iio:devicesX (i.e. buffer/ and scan_elements/); these subdirs > were actually 2 separate attribute groups on the iio_buffer object. > > Moving forward, if we want to allow more than one buffer per IIO device, > keeping 2 subdirectories for each IIO buffer is a bit cumbersome > (especially for userpace ABI). So, we will merge the attributes of these 2 > subdirs under a /sys/bus/iio/iio:devicesX/bufferY subdirectory. To do this, > we need to count all attributes first, and then distribute them based on > which buffer this is. For the first buffer, we'll need to also allocate the > legacy 2 attribute groups (for buffer/ and scan_elements/), and also a > /sys/bus/iio/iio:devicesX/buffer0 attribute group. > > For buffer1 and above, just a single attribute group will be allocated (the > merged one). > > Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com> One totally trivial thing noticed in here. If we happen to respin please tidy it up, if I take these as is I 'might' tweak it, or I might not bother depending on what mood I'm in later today. Jonathan > --- > drivers/iio/industrialio-buffer.c | 71 ++++++++++++++++--------------- > 1 file changed, 37 insertions(+), 34 deletions(-) > > diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c > index cc846988fdb9..23f22be62cc7 100644 > --- a/drivers/iio/industrialio-buffer.c > +++ b/drivers/iio/industrialio-buffer.c > @@ -1257,41 +1257,16 @@ static int __iio_buffer_alloc_sysfs_and_mask(struct iio_buffer *buffer, > { > struct iio_dev_attr *p; > struct attribute **attr; > - int ret, i, attrn, attrcount; > + int ret, i, attrn, scan_el_attrcount, buffer_attrcount; > const struct iio_chan_spec *channels; > > - attrcount = 0; > + buffer_attrcount = 0; > if (buffer->attrs) { > - while (buffer->attrs[attrcount] != NULL) > - attrcount++; > + while (buffer->attrs[buffer_attrcount] != NULL) > + buffer_attrcount++; > } > > - attr = kcalloc(attrcount + ARRAY_SIZE(iio_buffer_attrs) + 1, > - sizeof(struct attribute *), GFP_KERNEL); > - if (!attr) > - return -ENOMEM; > - > - memcpy(attr, iio_buffer_attrs, sizeof(iio_buffer_attrs)); > - if (!buffer->access->set_length) > - attr[0] = &dev_attr_length_ro.attr; > - > - if (buffer->access->flags & INDIO_BUFFER_FLAG_FIXED_WATERMARK) > - attr[2] = &dev_attr_watermark_ro.attr; > - > - if (buffer->attrs) > - memcpy(&attr[ARRAY_SIZE(iio_buffer_attrs)], buffer->attrs, > - sizeof(struct attribute *) * attrcount); > - > - attr[attrcount + ARRAY_SIZE(iio_buffer_attrs)] = NULL; > - > - buffer->buffer_group.name = "buffer"; > - buffer->buffer_group.attrs = attr; > - > - ret = iio_device_register_sysfs_group(indio_dev, &buffer->buffer_group); > - if (ret) > - goto error_free_buffer_attrs; > - > - attrcount = 0; > + scan_el_attrcount = 0; > INIT_LIST_HEAD(&buffer->scan_el_dev_attr_list); > channels = indio_dev->channels; > if (channels) { > @@ -1304,7 +1279,7 @@ static int __iio_buffer_alloc_sysfs_and_mask(struct iio_buffer *buffer, > &channels[i]); > if (ret < 0) > goto error_cleanup_dynamic; > - attrcount += ret; > + scan_el_attrcount += ret; > if (channels[i].type == IIO_TIMESTAMP) > indio_dev->scan_index_timestamp = > channels[i].scan_index; > @@ -1319,9 +1294,37 @@ static int __iio_buffer_alloc_sysfs_and_mask(struct iio_buffer *buffer, > } > } > > + attr = kcalloc(buffer_attrcount + ARRAY_SIZE(iio_buffer_attrs) + 1, > + sizeof(struct attribute *), GFP_KERNEL); nitpick, I'd have made that sizeof(*attr) > + if (!attr) { > + ret = -ENOMEM; > + goto error_free_scan_mask; > + } > + > + memcpy(attr, iio_buffer_attrs, sizeof(iio_buffer_attrs)); > + if (!buffer->access->set_length) > + attr[0] = &dev_attr_length_ro.attr; > + > + if (buffer->access->flags & INDIO_BUFFER_FLAG_FIXED_WATERMARK) > + attr[2] = &dev_attr_watermark_ro.attr; > + > + if (buffer->attrs) > + memcpy(&attr[ARRAY_SIZE(iio_buffer_attrs)], buffer->attrs, > + sizeof(struct attribute *) * buffer_attrcount); > + > + buffer_attrcount += ARRAY_SIZE(iio_buffer_attrs); > + attr[buffer_attrcount] = NULL; > + > + buffer->buffer_group.name = "buffer"; > + buffer->buffer_group.attrs = attr; > + > + ret = iio_device_register_sysfs_group(indio_dev, &buffer->buffer_group); > + if (ret) > + goto error_free_buffer_attrs; > + > buffer->scan_el_group.name = iio_scan_elements_group_name; > > - buffer->scan_el_group.attrs = kcalloc(attrcount + 1, > + buffer->scan_el_group.attrs = kcalloc(scan_el_attrcount + 1, > sizeof(buffer->scan_el_group.attrs[0]), > GFP_KERNEL); > if (buffer->scan_el_group.attrs == NULL) { > @@ -1341,12 +1344,12 @@ static int __iio_buffer_alloc_sysfs_and_mask(struct iio_buffer *buffer, > > error_free_scan_el_attrs: > kfree(buffer->scan_el_group.attrs); > +error_free_buffer_attrs: > + kfree(buffer->buffer_group.attrs); > error_free_scan_mask: > bitmap_free(buffer->scan_mask); > error_cleanup_dynamic: > iio_free_chan_devattr_list(&buffer->scan_el_dev_attr_list); > -error_free_buffer_attrs: > - kfree(buffer->buffer_group.attrs); > > return ret; > }
diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c index cc846988fdb9..23f22be62cc7 100644 --- a/drivers/iio/industrialio-buffer.c +++ b/drivers/iio/industrialio-buffer.c @@ -1257,41 +1257,16 @@ static int __iio_buffer_alloc_sysfs_and_mask(struct iio_buffer *buffer, { struct iio_dev_attr *p; struct attribute **attr; - int ret, i, attrn, attrcount; + int ret, i, attrn, scan_el_attrcount, buffer_attrcount; const struct iio_chan_spec *channels; - attrcount = 0; + buffer_attrcount = 0; if (buffer->attrs) { - while (buffer->attrs[attrcount] != NULL) - attrcount++; + while (buffer->attrs[buffer_attrcount] != NULL) + buffer_attrcount++; } - attr = kcalloc(attrcount + ARRAY_SIZE(iio_buffer_attrs) + 1, - sizeof(struct attribute *), GFP_KERNEL); - if (!attr) - return -ENOMEM; - - memcpy(attr, iio_buffer_attrs, sizeof(iio_buffer_attrs)); - if (!buffer->access->set_length) - attr[0] = &dev_attr_length_ro.attr; - - if (buffer->access->flags & INDIO_BUFFER_FLAG_FIXED_WATERMARK) - attr[2] = &dev_attr_watermark_ro.attr; - - if (buffer->attrs) - memcpy(&attr[ARRAY_SIZE(iio_buffer_attrs)], buffer->attrs, - sizeof(struct attribute *) * attrcount); - - attr[attrcount + ARRAY_SIZE(iio_buffer_attrs)] = NULL; - - buffer->buffer_group.name = "buffer"; - buffer->buffer_group.attrs = attr; - - ret = iio_device_register_sysfs_group(indio_dev, &buffer->buffer_group); - if (ret) - goto error_free_buffer_attrs; - - attrcount = 0; + scan_el_attrcount = 0; INIT_LIST_HEAD(&buffer->scan_el_dev_attr_list); channels = indio_dev->channels; if (channels) { @@ -1304,7 +1279,7 @@ static int __iio_buffer_alloc_sysfs_and_mask(struct iio_buffer *buffer, &channels[i]); if (ret < 0) goto error_cleanup_dynamic; - attrcount += ret; + scan_el_attrcount += ret; if (channels[i].type == IIO_TIMESTAMP) indio_dev->scan_index_timestamp = channels[i].scan_index; @@ -1319,9 +1294,37 @@ static int __iio_buffer_alloc_sysfs_and_mask(struct iio_buffer *buffer, } } + attr = kcalloc(buffer_attrcount + ARRAY_SIZE(iio_buffer_attrs) + 1, + sizeof(struct attribute *), GFP_KERNEL); + if (!attr) { + ret = -ENOMEM; + goto error_free_scan_mask; + } + + memcpy(attr, iio_buffer_attrs, sizeof(iio_buffer_attrs)); + if (!buffer->access->set_length) + attr[0] = &dev_attr_length_ro.attr; + + if (buffer->access->flags & INDIO_BUFFER_FLAG_FIXED_WATERMARK) + attr[2] = &dev_attr_watermark_ro.attr; + + if (buffer->attrs) + memcpy(&attr[ARRAY_SIZE(iio_buffer_attrs)], buffer->attrs, + sizeof(struct attribute *) * buffer_attrcount); + + buffer_attrcount += ARRAY_SIZE(iio_buffer_attrs); + attr[buffer_attrcount] = NULL; + + buffer->buffer_group.name = "buffer"; + buffer->buffer_group.attrs = attr; + + ret = iio_device_register_sysfs_group(indio_dev, &buffer->buffer_group); + if (ret) + goto error_free_buffer_attrs; + buffer->scan_el_group.name = iio_scan_elements_group_name; - buffer->scan_el_group.attrs = kcalloc(attrcount + 1, + buffer->scan_el_group.attrs = kcalloc(scan_el_attrcount + 1, sizeof(buffer->scan_el_group.attrs[0]), GFP_KERNEL); if (buffer->scan_el_group.attrs == NULL) { @@ -1341,12 +1344,12 @@ static int __iio_buffer_alloc_sysfs_and_mask(struct iio_buffer *buffer, error_free_scan_el_attrs: kfree(buffer->scan_el_group.attrs); +error_free_buffer_attrs: + kfree(buffer->buffer_group.attrs); error_free_scan_mask: bitmap_free(buffer->scan_mask); error_cleanup_dynamic: iio_free_chan_devattr_list(&buffer->scan_el_dev_attr_list); -error_free_buffer_attrs: - kfree(buffer->buffer_group.attrs); return ret; }
If we want to merge the attributes of the buffer/ and scan_elements/ directories, we'll need to count all attributes first, then (depending on the attribute group) either allocate 2 attribute groups, or a single one. Historically an IIO buffer was described by 2 subdirectories under /sys/bus/iio/iio:devicesX (i.e. buffer/ and scan_elements/); these subdirs were actually 2 separate attribute groups on the iio_buffer object. Moving forward, if we want to allow more than one buffer per IIO device, keeping 2 subdirectories for each IIO buffer is a bit cumbersome (especially for userpace ABI). So, we will merge the attributes of these 2 subdirs under a /sys/bus/iio/iio:devicesX/bufferY subdirectory. To do this, we need to count all attributes first, and then distribute them based on which buffer this is. For the first buffer, we'll need to also allocate the legacy 2 attribute groups (for buffer/ and scan_elements/), and also a /sys/bus/iio/iio:devicesX/buffer0 attribute group. For buffer1 and above, just a single attribute group will be allocated (the merged one). Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com> --- drivers/iio/industrialio-buffer.c | 71 ++++++++++++++++--------------- 1 file changed, 37 insertions(+), 34 deletions(-)